WO2015176997A1

WO2015176997A1 - Threads having varying thread diameter and production method for such threads

Info

Publication number: WO2015176997A1
Application number: PCT/EP2015/060443
Authority: WO
Inventors: Martin Dauner; Erhard Müller; Sven Oberhoffner; Martin Hoss
Original assignee: Itv Denkendorf Produktservice Gmbh
Priority date: 2014-05-20
Filing date: 2015-05-12
Publication date: 2015-11-26
Also published as: EP3146096A1; DE102014209606B4; DE102014209606A1

Abstract

The invention relates to a thread having a varying thread diameter, comprising a) longitudinal thread segments, along which the thread diameter is constant or substantially constant, and b) longitudinal thread segments along which the thread diameter varies, wherein longitudinal thread segments a) are longer than longitudinal thread segments b). The invention further relates to a method for producing a thread, comprising the following steps: i) coextruding a thread core component and a sheath component from a shaping outlet opening of an extrusion device and thus forming an intermediate thread having a thread core and having a sheath surrounding the thread core, and ii) removing the sheath from the thread core, wherein during the performance of step i) the mass throughput of the thread core component and preferably of the sheath component is varied and/or the intermediate thread is drawn off at a varying speed after exiting from the outlet opening. The invention further relates to a method for producing a thread, comprising the following steps: i) extruding a thread polymer from a shaping outlet opening of an extrusion device and thus forming an intermediate thread, and ii) producing anchoring structures on the intermediate thread, wherein during the performance of step i) the mass throughput of the thread polymer is varied and/or the intermediate thread is drawn off at a varying speed after exiting from the outlet opening. The invention further relates to a thread having a thread diameter that varies in a longitudinal direction of the thread, which thread diameter is or can be produced according to one of the two methods mentioned above. Furthermore, the invention relates to a thread having a thread diameter that varies in a longitudinal direction of the thread, wherein the thread is a thread core of a core-sheath thread from which the sheath has been removed. In addition, the invention relates to a medical product, and to a kit, in particular in the form of a needle/thread combination.

Description

Threads with varying thread diameter and method of manufacturing such threads

Application area and technical background

The invention relates to yarns with thread diameter varying in the yarn longitudinal direction and to a process for producing such yarns.

Melt-blow nonwovens are known as coalescers, wherein the nonwoven fabric is formed from meltblown polymer fibers, the diameter of individual fibers varying along their length such that a single fiber has different diameters at different points along its length Length. The typical diameter of the individual filaments in melt-blow nonwovens is between 1 μηη and 10 μηη.

The subject of WO 99/15470 A1 are optical fibers of silicon dioxide, which have a varying diameter due to the use of different drawing rates during the manufacturing process.

US 4,631,162 relates to irregular multifilament hollow fibers which have sinusoidal filament constituents.

From the documents JP 09217221 A and JP 09217222 A, a raw yarn (vinylidene fluoride) for fly fishing is known in each case, for the production of which the extrusion rate and the take-off speed of the resulting yarn are varied.

GB 535,263 discloses the production of tapered filaments for bristles and fishing lines. To produce the filaments, the filament material throughput and the take-off speed of the resulting filaments are varied.

The publications GB 990,780 and GB 813,857 each show multifilaments each having a diameter varying in the longitudinal direction. To produce the multifilaments, jet nozzles of variable diameter (GB 990,780) and guide elements which change the way from the nozzle to the winding in the short term (GB 813,857) are used.

The subject of EP 0 270 019 A2 is a multifilament yarn which is composed of two ribbon-shaped, filament-like constituents, at least one filamentous core constituent and at least two middle, filament-like constituents. The core component extends sinusoidally along the longitudinal axis of the filament. US 2012/0010656 A1 relates to a surgical suture having suture portions that differ in diameter.

The US 2013/0101844 A1 relates to profiled individual filaments which are glued together by means of a spinning process in a stochastic, so random manner, whereby different overall cross-sectional structures can be formed.

The threads described in the prior art sometimes have the disadvantage that the variation of the thread diameter can not be sufficiently profiled and defined, which limits their potential application.

Task and solution

It is an object of the invention to provide threads with a varying thread diameter, which in particular circumvent the disadvantages known in the case of generic threads. Furthermore, it is an object of the invention to provide manufacturing methods for such threads. It is a further object of the invention to provide a technical textile, a medical product and a kit, which each have at least one thread with a varying thread diameter.

This is inventively achieved by threads according to claims 1 and 15, a method according to claim 9, a medical product according to claim 16 and a medical kit according to claim 17. Preferred embodiments of the invention are described, for example, in the subclaims, which are hereby incorporated by express reference into the content of the description. Further solutions are discussed in the description.

According to a first aspect, the invention relates to a thread having a varying (changing) thread diameter.

The thread according to the invention has thread longitudinal sections, i. two or more thread longitudinal sections, along which the thread diameter is constant or substantially constant, hereinafter referred to as thread longitudinal sections a).

In addition, the thread according to the invention has at least one thread longitudinal section along which the thread diameter varies, ie along which the thread diameter changes, hereinafter referred to as the at least one thread longitudinal section b). Due to the varying thread diameter, the at least one thread longitudinal section b) has a gradient in the longitudinal direction of the thread relative to the thread diameter.

The thread longitudinal sections a) are preferably longer than the at least one thread longitudinal section b), or in other words, the at least one thread longitudinal section b) is preferably shorter than the thread longitudinal sections a). In this way, a "sharper", i.e. steeper, diameter gradient in the longitudinal direction of the thread or of the at least one thread longitudinal section b) can be formed with particular advantage.

The present invention is further based on the surprising finding that such a "sharpening" of the diameter gradient, in particular starting from a coextruded core-sheath thread, ie a thread with a core-sheath structure (or with a core-sheath structure ), by subsequent removal of the shell (stripping) can realize, as will be explained in more detail below.

Unless defined otherwise, the term "diameter" as used in the present invention corresponds to the usual expert understanding unless otherwise defined the present invention, the thread diameter or the diameter of a longitudinal portion of the thread not attributed.

For the purposes of the present invention, the expression "at least one thread longitudinal section b)" means a thread longitudinal section b) or a multiplicity of thread longitudinal sections b), ie two or more thread longitudinal sections b) Executions mutatis mutandis in the event that the thread has several thread longitudinal sections b).

Along the at least one thread longitudinal section b), the thread diameter may vary continuously, in particular linearly or substantially linearly, and / or discontinuously, in particular stepwise, preferably increase or decrease.

A linear or substantially linear increase or decrease in the thread diameter along the at least one yarn longitudinal section b) is particularly preferred according to the invention. Preferably, the increase or decrease in the thread diameter along the at least one thread longitudinal section b) in an unstretched state of the thread is subject to an absolute pitch of 20 mm per cm thread length to 0.01 mm per cm thread length, in particular 15 mm per cm thread length to 0.02 mm per cm thread length , preferably 10 mm per cm thread length to 0.02 mm per cm thread length. For the purposes of the present invention, the term "absolute slope" is understood to mean the absolute measure, that is to say independent of the sign, of the steepness of a straight line or a curve which characterizes the variation of the thread diameter.

By contrast, after stretching the thread, the values for the absolute gradient can be significantly smaller. Thus, in the stretched state of the thread, the increase or decrease in the thread diameter along the at least one thread longitudinal section b) an absolute pitch of 7 mm per cm thread length to 0.002 mm per cm thread length, in particular 5 mm per cm thread length to 0.004 mm per cm thread length, preferably 4 mm per cm of thread length to 0.004 mm per cm of thread length, to follow.

The thread longitudinal sections a) can have a total length of 50% to 99%, in particular 70% to 99%, preferably 80% to 99%, based on the total length of the thread. The at least one thread longitudinal section b) can have a length fraction of 1% to 50%, in particular 1% to 30%, preferably 1% to 20%, based on the total length of the thread. The length portions described in this paragraph are particularly advantageous for medical uses of the thread.

For non-medical uses of the thread, it may be advantageous if the thread longitudinal sections a) a total length of 1% to 50%, in particular 1% to 30%, preferably 1% to 20%, and corresponding to the at least one thread longitudinal section b) a length portion from 50% to 99%, in particular 70% to 99%, preferably 80% to 99%, in each case based on the total length of the thread.

The thread longitudinal sections a) comprise in a further embodiment at least one thread longitudinal section, ie one or more thread longitudinal sections, along which (the) the thread continuously has a constant or substantially constant thread diameter di, hereinafter referred to as the at least one thread longitudinal section a-ι), and at least one thread longitudinal section, ie one or more thread longitudinal sections, along which (the) the thread has a constant or substantially constant thread diameter d ₂ , hereinafter referred to as the at least one thread longitudinal section a ₂ ), where di> d ₂ . In other words, the thread may comprise thread long sections a) which differ from each other in terms of their diameter. The diameter di may be greater than the diameter d ₂ by 10% to 200%, in particular 20% to 200%, preferably 20% to 100%.

In a further embodiment, the thread next to the thread longitudinal sections a) a plurality, i. two or more, Fadenlangsabschnitte b), along which the thread diameter continuously, in particular linear or substantially linear, or discontinuous, in particular stepped, varies, preferably increases and / or decreases.

Preferably, the thread has a plurality of thread long sections b), along which the thread diameter increases continuously, in particular linearly or substantially linearly, or discontinuously, in particular stepwise.

Further preferably, the thread on several Fadenlangsabschnitte b) along which the thread diameter decreases continuously, in particular linear or substantially linear, or discontinuous, in particular stepped.

If the thread has a plurality of thread long sections b), the thread long sections a) and b) can be singulated or periodic along the thread. According to the invention it is preferred if the thread has an alternating sequence of the thread longitudinal sections a) and b).

In a further embodiment, the thread in the longitudinal direction has a preferably recurring sequence of following thread longitudinal sections, in particular in the order a-ι), b), a ₂ ), on: a-ι) thread longitudinal section, along which the thread continuously a constant or substantially b) thread longitudinal section, along which the thread diameter, preferably linearly or substantially linearly, varies between di and a value d ₂ and a ₂ ) thread longitudinal section, along which the thread has a constant or substantially constant thread diameter d ₂ throughout where di> d ₂ .

The total length of the sequence of the thread longitudinal sections a-1), b), a ₂ ) can be <30 cm, in particular <20 cm, preferably <10 cm, in the unstretched state of the thread. These overall lengths are particularly advantageous in medical applications of the thread. The thread may in principle have a circular cross-section or a non-circular cross-section, in particular an oval, ellipsoidal or polygonal, such as triangular, rectangular, square, rhombic, pentagonal, hexagonal or star-shaped cross-section.

Furthermore, the thread may in principle comprise a resorbable, partially absorbable or non-resorbable polymer or a corresponding polymer blend (blend) or be formed from such a polymer or such a polymer blend. The polymer may be a homo- and / or copolymer. The copolymer may in turn be selected from the group comprising random copolymer, segmented copolymer (block copolymer), graft copolymer and mixtures (blends) thereof. For the purposes of the present invention, the term "copolymer" is to be understood as meaning a polymer which is composed of at least two recurring monomer units. According to this definition, the term "copolymer", for example bipolymers, i. Polymers composed of two preferably repeating monomer units and terpolymers, i. Polymers, which are composed of three preferably recurring monomer units detected.

Preferably, the thread comprises at least one polymer or is formed from at least one polymer which is selected from the group comprising polyolefins, polyamides, polyesters, polycarbonates, polyurethanes, in particular thermoplastic polyurethanes, polyhydroxyalkanoates, copolymers thereof, salts thereof, stereoisomers thereof and Mixtures (blends) thereof.

For example, the thread may comprise at least one polymer or be formed from at least one polymer selected from the group consisting of polyethylene, low density polyethylene, high density polyethylene, high molecular weight polyethylene, ultra high molecular weight polyethylene, polypropylene, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, nylon 6, Nylon 6-6, nylon 6-12, nylon 12, polytetrafluoroethylene, polyvinylidene difluoride, polytetrafluoropropylene, polyhexafluoropropylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polyglycolic acid, polylactic acid, polydioxanone, poly-3-hydroxybutyric acid, poly-4 hydroxybutyric acid, polytrimethylene carbonate, poly-ε-caprolactone, copolymers thereof, salts thereof, stereoisomers thereof and mixtures (blends) thereof.

A preferred terpolymer for the thread is composed for example of recurring glycolide, ε-caprolactone and Trimethylencarbonateinheiten and commercially available under the name Monosyn ^® . In a further embodiment, the thread is provided with at least one additive. In this way, a thread can be realized whose additive proportion varies in the longitudinal direction of the thread. According to the embodiment of the thread provided according to the invention, thread longitudinal sections along which the proportion of the at least one additive is constant or essentially constant (thread longitudinal sections a) and / or thread longitudinal sections along which the proportion of the at least one additive varies (thread longitudinal sections b)). As a result, the proportion of the at least one additive may vary continuously, preferably linearly or substantially linearly, or discontinuously, in particular stepwise, preferably - or lose weight.

The at least one additive may be incorporated into the thread. For example, the at least one additive may be part of a polymer compound used to make the thread. Alternatively or in addition, the at least one additive can coat the thread or be part of a thread coating.

The at least one additive is in particular selected from the group consisting of antimicrobial, in particular antibiotic, active ingredients, antiinflammatory agents, disinfectants, analgesic agents, scar reducing agents, cytostatics, pore-forming substances (chemical or physical), plasticizers, lubricants, dyes, pigments, radioactive substances, radio-opaque substances, nucleating agents, matting agents, density-influencing substances, conductive substances, refractive substances, magnetizable substances and mixtures thereof.

For example, resistance gradients along the at least one yarn longitudinal section b) can be formed by an additive with conductive substances, which can be used, for example, for the production of so-called "smart textiles".

By an additive with refractive substances light optical properties can be transferred to the thread.

Additive dyeing, for example, allows the production of effect threads, in particular surgical threads with tinning effects.

An additive with radioactive substances allows, for example, a use of the thread according to the invention in tumor therapy. In a particularly preferred embodiment, the thread has anchoring structures. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues.

The anchoring structures preferably protrude from the thread surface. The term "thread surface" in the context of the present invention means in particular the thread surface of the thread longitudinal sections a) and / or of the at least one thread longitudinal section b).

The anchoring structures are formed in a further embodiment by means of incisions in the thread.

The anchoring structures can in principle be formed in at least one row-shaped arrangement, staggered arrangement, zigzag arrangement, spiral arrangement, randomized arrangement or in combinations thereof in the longitudinal and / or transverse direction, preferably in the longitudinal direction, on the thread surface.

The anchoring structures can furthermore have a unidirectional and / or multidirectional, in particular bidirectional, arrangement on the thread surface. The arrangement of the anchoring structures can in this case in particular in the longitudinal and / or transverse direction of the thread, preferably in the longitudinal direction of the thread, be formed. Unidirectionally arranged anchoring structures are characterized in the sense of the present invention in that they are oriented only in one direction of the thread. Bidirectionally arranged anchoring structures are characterized in the sense of the present invention, however, by the fact that a part of the anchoring structures are oriented in one direction and another part of the anchoring structures in a direction opposite thereto. In particular, in the case of bidirectionally arranged anchoring structures, a part of the anchoring structures can be oriented along a first thread longitudinal section in the direction of a second thread longitudinal section, while another part of the anchoring structures can be oriented along the second thread longitudinal section in the direction of the first thread longitudinal section.

According to the invention, a unidirectional or bidirectional design of the anchoring structures in the longitudinal direction of the thread is preferred.

According to the invention, it may be particularly preferred if the thread has on its surface two rows of bidirectional anchoring structures, which are each arranged offset in the longitudinal direction of the thread and in particular in its circumferential direction by 180 degrees. In a further embodiment, the anchoring structures barb, coat of arms, shield, dandruff, wedge, thorn, especially rosendornen-, sting, arrow, V, and / or W-shaped.

The formation of the anchoring structures in the form of barbs is particularly preferred according to the invention.

Further preferably, the anchoring structures are each formed pointed or pointed at their protruding from the thread surface ends.

In principle, the anchoring structures can be formed on the thread longitudinal sections a) and / or the at least one thread longitudinal section b).

The anchoring structures may in particular be formed only on certain thread longitudinal sections a), whereas other thread longitudinal sections a) may be free of anchoring structures of the type described above.

Preferably, the anchoring structures are formed only on the already mentioned thread longitudinal sections a-i). In this way - in the case of a medical thread - an improved anchoring with a surrounding body tissue can be achieved, since the thread longitudinal sections a-i) have the smallest distance to the surrounding body tissue after application of the thread, possibly even being directly surrounded by the body tissue. Furthermore, lower cutting depths are required to form the anchoring structures, which reduces tissue trauma and on top of that the mechanical stability, in particular the linear tensile strength, of the thread can be increased. In the case of the embodiment described in this paragraph, it may optionally additionally be provided to form anchoring structures on sections of the at least one yarn longitudinal section b) which are directly adjacent to the thread longitudinal sections a-i). If the cutting depth (for the formation of the anchoring structures) is not changed in relation to the thread longitudinal sections, anchoring structures can be formed on said sections, the size of which decreases with increasing distance from the thread longitudinal sections a-i).

In a further embodiment, the thread is stretched or unstretched.

The thread may further be a monofilament or multifilament, in particular a braided multifilament. In the case of a multifilament-shaped configuration of the thread, sen individual filaments, in particular at least a part thereof, the thread longitudinal sections a) and the at least one thread longitudinal section b).

The thread can furthermore be in the form of an endless thread, in particular continuous monofilament, or of a cut-to-length thread.

The thread of the invention may further be a solid thread, i. around a thread without lumen, act.

Alternatively, the thread of the invention may be a hollow thread, i. a thread with a lumen, preferably with a lumen extending in the longitudinal direction of the thread act.

According to a particularly preferred embodiment, the thread is a thread core of a stripped core-sheath thread. In other words, the thread according to the invention is particularly preferably a thread which, starting from a core-sheath-structured thread (or core-sheath construction), is removed by removing the sheath, i. by stripping a thread with core-shell structure, is made.

The thread according to the invention opens up a variety of fields of application, both in the technical and in the medical field.

Thus, the thread according to the invention is generally suitable for the production of technical textiles, in particular in the form of woven, knitted, knitted, laid or nonwoven fabrics. Due to a varying thread diameter, it is possible to achieve gradients in terms of pore size or mesh size and / or with regard to an additive gradient in the textile surface.

Due to the varying thread diameter, the thread according to the invention is suitable for example for the production of textiles with light-optical effects that can be used for example as automotive textiles, home textiles and / or for the decoration of furniture and rooms.

Another field of application of the thread, which can be derived in particular from the presence of thread longitudinal sections with decreasing thread diameter (thread longitudinal sections b)), consists in the production of textile gripping arms. However, preferred are medical uses of the thread. Thus, the thread is particularly preferably intended for use as a medical, in particular surgical, thread (suture). The thread is preferably a medical, in particular surgical, thread (medical, in particular surgical, suture material). Further medical uses will be explained in more detail below.

According to a second aspect, the invention relates to a method for producing a thread, in particular a thread according to the first aspect of the invention. The process comprises the following steps: i) coextruding a core core component and a shell component from a shaping outlet opening of an extrusion device to form an intermediate thread having a core and a core surrounding the core (sheath-core, ie sheath-core structure) ) and ii) removing the shell from the intermediate thread, ie Stripping the intermediate thread, wherein in performing step i) the mass flow rate of the thread core component and preferably the shell component is varied (changed) and / or the intermediate thread is withdrawn after exiting the outlet opening at a varying (varying) speed.

The mantle can basically only partially surround the thread core. According to the invention, it is preferred if the thread core is completely surrounded by the jacket.

By varying the mass throughput of the thread core component and preferably the sheath component and / or by varying the take-off speed of the intermediate thread and by subsequently removing the sheath, thread longitudinal sections can be formed, along which the thread diameter varies (changes), preferably increases or decreases. In that regard, reference is made in particular to the statements made in the context of the first aspect of the invention.

By (substantially) keeping constant the total mass throughput, ie the sum of the mass throughput of the thread core component and the mass throughput of the sheath component, and / or by (substantially) keeping constant the take-off speed of the intermediate thread, an intermediate thread with a constant or substantially realize constant overall diameter, wherein the intermediate thread filament longitudinal sections with a constant ratio of filament core to sheath component (see the thread longitudinal sections Ui) and u ₃ ) of Figure 1) and thread longitudinal sections with a varying, preferably increasing or decreasing, the ratio of Fadenkern- Sheath component (see the thread longitudinal sections u ₂ ) and u ₄ ) of Figure 1). The resulting after removal of the jacket thread (stripped intermediate thread) preferably has thread longitudinal sections, along which the thread diameter is constant or substantially constant, and thread longitudinal sections, along which the thread diameter varies, preferably increases or decreases.

Specifically, by varying the mass throughput of the thread core component and preferably the sheath component, it is particularly advantageous to produce a gradient with respect to the thread core diameter and preferably with respect to the sheath thickness and thus preferably also with respect to the ratio of thread core diameter to sheath thickness.

In a particularly preferred embodiment, the mass flow rate of the thread core component and the mass flow rate of the shell component are varied in a contrasting manner, so that the total mass flow rate composed of the two partial mass flow rates remains constant or substantially constant at any point in time.

For example, a lower mass throughput of the thread core component can be compensated by a correspondingly higher mass throughput of the shell component or vice versa. In this way, the total mass flow rate and thus the total diameter of the intermediate thread, as already mentioned, can be kept constant or substantially constant.

According to the statements made so far, the mass flow rate of the thread core component, and preferably of the shell component, can be varied periodically or occasionally when performing step i). In particular, in an alternating sequence, the mass flow rate of the thread core component, and preferably the sheath component, can be kept constant or substantially constant and varied, or vice versa.

The inventively provided extrusion device usually includes an extruder for the thread core component and an extruder for the shell component. Both extruders can each be operated with their own spinning pump. Furthermore, the extrusion device expediently has a first melt channel for the thread core composite. NEN and a second melt channel for the shell component, which surrounds the first melt channel in the region of the spinneret usually concentric. The first and the second melt channel expediently open into a common outlet opening of the extrusion device.

In order to vary the mass throughput of the thread core component and preferably of the shell component, in one preferred embodiment the rotational speed of a spinning pump responsible for the extrusion of the thread core component and preferably the rotational speed of a spinning pump responsible for the extrusion of the shell component are varied.

If the mass throughput of the core component or sheath component is to be reduced, the speed of the spinning pump responsible for the extrusion of the thread core component or the speed of the spinning pump responsible for the extrusion of the sheath component is reduced. If, on the other hand, the mass throughput of the thread core component or sheath component is to be increased, the speed of the spinning pump responsible for the extrusion of the thread core component or the speed of the spinning pump responsible for the extrusion of the sheath component is increased.

For example, in order to form an intermediate thread with a constant or substantially constant thread diameter, the speed of the spin pump responsible for the extrusion of the thread core component can be reduced from 10 revolutions per minute to 5 revolutions per minute and, correspondingly, the speed of the spinning pump responsible for the extrusion of the shell component 5 revolutions / min increased to 10 revolutions / min.

Alternatively, the mass flow rate of the core core component and preferably the sheath component may be varied by controlling the mass flow rate within the aforementioned melt channels, for example by means of controllable switches that reduce or close and, if necessary, increase or open the cross-sectional area of the melt channels, or by means of an adjustable bypass , To vary the take-off speed, preferably the rotational speed of a godet responsible for the withdrawal of the intermediate yarn is varied.

According to the statements made so far, the withdrawal speed of the intermediate thread can be varied periodically or occasionally. In particular, the withdrawal speed of the intermediate thread can be kept constant and varied in alternating sequence or vice versa. In a particularly preferred embodiment, the withdrawal speed of the intermediate thread is increased while the mass flow rate of the thread core component is lowered. Alternatively, the take-off speed of the intermediate yarn can be lowered while the mass flow rate of the yarn core component is increased. This makes it possible to realize steeper gradients with respect to the ratio of thread core diameter to shell thickness (see the thread longitudinal sections u ₂ ) and u ₄ ) of FIG. 1). If these method measures combined with a subsequent removal of the jacket, so can be formed in this way steeper diameter gradients in the longitudinal direction of the stripped thread.

To perform step ii), d. H. In principle, both chemical and physical techniques are considered for removing the sheath from the thread core. For example, the jacket can be removed by dissolving in a solvent in which the filament core is insoluble. Alternatively, the shell can be removed by means of a chemical or enzymatic reaction, such as, for example, hydrolysis, in particular ester hydrolysis. If the melting point of the sheath component is lower than the melting point of the thread core component, a suitable physical method for removing the sheath is, for example, to melt the sheath by means of heat supply and drain it from the thread core. Furthermore, the jacket can be removed by means of a stretching of the intermediate thread by the shell breaks apart during the drawing process and detach from the thread core, in particular mechanically detach leaves.

To form the additive gradient described in the context of the first aspect of the invention, it is provided in a further embodiment that at least one additive is added in varying amounts to the thread core component. With regard to suitable additives, reference is made in full to what has been said in the context of the first aspect of the invention.

The core component and / or the sheath component may in principle comprise a resorbable, partially absorbable or non-resorbable polymer or a corresponding polymer mixture (blend) or be formed from such a polymer or such a polymer mixture. In that regard, reference is also made to the statements made in the context of the first aspect of the invention.

Preferably, the thread core component and / or the sheath component comprise at least one polymer or are formed from at least one polymer which is selected from the group comprising polyolefins, polyamides, polyesters, polycarbonates, polyurethanes, in particular the thermoplastic polyurethanes, polyhydroxyalkanoates, copolymers thereof, salts thereof, stereoisomers thereof, and mixtures (blends) thereof.

For example, the thread core component and / or the sheath component may comprise at least one polymer or be formed from at least one polymer which is selected from the group consisting of polyethylene, low density polyethylene, high density polyethylene, high molecular weight polyethylene, ultra high molecular weight polyethylene, polypropylene, polyethylene terephthalate, Polypropylene terephthalate, polybutylene terephthalate, nylon 6, nylon 6-6, nylon 6-12, nylon 12, polytetrafluoroethylene, polyvinylidene difluoride, polytetrafluoropropylene, polyhexafluoropropylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polyglycolic acid, polylactic acid, polydioxanone, poly-3-hydroxybutyric acid, Poly-4-hydroxybutyric acid, polytrimethylene carbonate, poly-e-caprolactone, copolymers thereof, salts thereof, stereoisomers thereof, and mixtures (blends) thereof.

In principle, the thread can be left in an unstretched state.

However, in an embodiment which is advantageous in terms of stability, the thread is drawn. Drawing of the thread may take place before or after performing step ii), i. Stripping the intermediate thread, be made.

The stretching is preferably carried out under heat, in particular in a temperature range from 20 ° C to 140 ° C. To generate a heat advantageous for the stretching, for example, infrared rays, electrically heated continuous furnaces, tempered water baths or chambers with steam can be used. For drawing, the thread can be guided over a roller or godet system, a so-called draw line. The rollers or godets can in this case have different speeds of rotation. Preferably, each successive roll or godet has a higher rotational speed than the preceding roll or godet of the draw line. Alternatively, the last roll or galette of such stretch line may be up to 15% slower than the penultimate roll or godet of the draw line, thereby relaxing with an increase in the elasticity of the thread. As an alternative to the continuous drawing just described, the thread can be stretched discontinuously. For a discontinuous stretching, the thread can be clamped between the clamping jaws of a tensioning device and then stretched under the effect of temperature.

The orientation can generally be carried out with a draw ratio of 1.5 to 12, in particular 2.5 to 10, preferably 3.0 to 8. In a preferred embodiment, anchoring structures, in particular anchoring structures projecting from the surface of the intermediate thread, or - after performing step ii) - anchoring structures projecting from the surface of the stripped thread, are produced. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues.

Particularly preferably, the anchoring structures are produced in the form of barbs on the surface of the thread. The anchoring structures are preferably produced by means of incisions in the thread. The production of the anchoring structures can be carried out before or after carrying out step ii).

If the anchoring structures are produced by means of cuts in the intermediate thread, it may be expedient to set the cutting depth such that it is greater than the thickness of the jacket. In this way it is ensured that the thread core of the intermediate thread is also cut.

The anchoring structures are produced in a further embodiment only on thread longitudinal sections of the intermediate thread whose core diameter is greater than the shell thickness. In this way, comparatively small cutting depths are sufficient to ensure a cutting of the thread core. In addition, the mechanical stability, in particular the linear tensile strength, of the resulting yarn is greater.

On the other hand, if the anchoring structures are made after performing step ii), i. After the jacket has been removed from the thread core, it is preferred if the anchoring structures are (only) formed on thread longitudinal sections with a thicker thread diameter.

The anchoring structures can basically be generated thermally, for example by means of a laser, and / or mechanically, for example by means of a corresponding cutting device. Suitable cutting devices suitably comprise a cutting bed, at least one cutting blade and holding devices for the thread to be cut. With particular advantage, a cutting bed with a groove can be used for the mechanical cutting of the anchoring structures, wherein the groove is provided for receiving the intermediary thread to be cut or - after performing step ii) - of the stripped thread to be cut. The anchoring structures can basically be produced in a stretched or unstretched state of the intermediate thread or stripped thread. In particular, the anchoring structures can be produced before or after stretching the intermediate thread or stripped thread.

Preferably, the intermediate thread or stripped thread is cut before or after stretching to create the anchoring structures.

When the intermediate thread or stripped thread is pre-stretched, i. In the still unstretched state, cut, anchoring structures projecting from the thread surface can be produced by means of a subsequent stretching, in particular with formation of special geometries as a function of the cutting distance, cutting depth and cutting angle. Preferably, such a cut, stripped thread has a constant or substantially constant diameter, a so-called effective thread diameter, after being stretched over its entire length. For the purposes of the present invention, the expression "effective thread diameter" is intended to mean the residual diameter of a thread according to the invention after the production of anchoring structures, preferably by means of incision, and after stretching (see FIG. 8) .This ensures a linear tensile force which is almost the same in all longitudinal thread segments and enables in particular a needling of the thread using small needle diameter.

In contrast, by means of incising a stretched intermediate thread or a stretched, stripped thread directly, i. without the inclusion of a further step, anchoring structures projecting from the thread surface are produced.

In a further embodiment, the thread to be produced may be an endless thread, in particular an endless monofilament, or a cut thread, in particular in the form of a monofilament.

In principle, the thread can be cut to length even before carrying out step ii). In other words, it may be provided according to the invention that the intermediate thread is cut to length.

However, it is preferred if the thread is cut to length only after carrying out step ii), ie the stripped thread, in particular to obtain the final thread to be produced. In a further embodiment, after performing step ii) and in particular after stretching, the thread is subjected to a subsequent treatment, a so-called "post-treatment." For this purpose, the thread is tempered in vacuo for this purpose, whereby the crystallinity of the thread can be increased A further advantage that can be achieved by such a post-treatment is a reduced susceptibility of the thread to shrinkage.

With regard to further features and advantages of the method, in particular threads that can be produced thereby, reference is made to the statements made in the context of the first aspect of the invention.

According to a third aspect, the invention relates to a further method for producing a thread, in particular a thread according to the first aspect of the invention. The method comprises the following steps: i) extruding a thread polymer from a shaping outlet opening of an extrusion device to form an intermediate thread and preferably ii) creating anchoring structures, preferably for anchoring in biological, in particular human and / or animal, tissues, on the intermediate thread, wherein in performing step i) the mass flow rate of the filament polymer is varied (changed) and / or the intermediate thread is withdrawn after exiting the outlet port at a varying (varying) speed.

By varying the mass throughput of the filament polymer and / or by varying the take-off speed of the intermediate filament, filament longitudinal sections can be formed, along which the filament diameter varies (changes), preferably increases or decreases. In that regard, reference is made entirely to the statements made in the context of the first aspect of the invention.

By (substantially) keeping constant the mass throughput of the yarn polymer and / or by (substantially) keeping constant the take-off speed of the intermediate yarn, thread longitudinal sections can be formed, along which the yarn diameter is (essentially) constant. In that regard, reference is equally made to the statements made in the context of the first aspect of the invention. The mass flow rate of the filament polymer when performing step i) can be varied periodically or occasionally. In particular, in an alternating sequence, the mass flow rate of the yarn polymer can be kept constant and varied or vice versa.

The extrusion apparatus provided for this aspect of the invention usually includes an extruder for the filament polymer, the extruder being operated with a spinning pump. Furthermore, the extrusion device expediently has a melt channel for the thread polymer, wherein the melt channel usually opens into the outlet opening of the extrusion device.

In order to vary the mass throughput of the yarn polymer, the speed of a spinning pump responsible for the extrusion of the yarn polymer is varied in a preferred embodiment.

If the mass flow rate of the filament polymer is to be reduced, the rotational speed of the spinning pump responsible for the extrusion of the filament polymer is reduced. If, on the other hand, the mass throughput of the filament polymer is to be increased, the rotational speed of the spinning pump responsible for the extrusion of the filament polymer is increased.

Alternatively, the mass flow rate of the filament polymer can be varied by controlling the mass flow rate within the aforementioned melt channel, for example by means of controllable switches which reduce or close the cross-sectional area of the melt channel and if necessary increase or open again, or by means of an adjustable bypass.

To vary the take-off speed, preferably the rotational speed of a godet responsible for the withdrawal of the intermediate yarn is varied.

In a particularly preferred embodiment, the draw-off speed of the intermediate yarn is increased at a time at which the mass flow rate of the yarn polymer is lowered. Alternatively, the take-off speed of the intermediate yarn can be lowered at a time at which the mass flow rate of the yarn polymer is increased. This makes it possible to realize particularly steep diameter gradients.

The withdrawal speed of the intermediate thread can be varied periodically or occasionally. In particular, the withdrawal speed of the intermediate thread can be kept constant and varied in alternating sequence or vice versa. The thread polymer may in principle be a resorbable, partially absorbable or non-absorbable polymer or a corresponding polymer blend (blend). In that regard, reference is made to the statements made in the context of the first aspect of the invention.

The yarn polymer is preferably selected from the group comprising polyolefins, polyamides, polyesters, polycarbonates, polyurethanes, in particular thermoplastic polyurethanes, polyhydroxyalkanoates, copolymers thereof, salts thereof, stereoisomers thereof and mixtures (blends) thereof.

For example, the filament polymer may be selected from the group consisting of polyethylene, low density polyethylene, high density polyethylene, high molecular weight polyethylene, ultra high molecular weight polyethylene, polypropylene, polyethylene terephthalate, polypropylene terephthalate, polybutylene terephthalate, nylon 6, nylon 6-6, nylon 6-12, nylon 12, polytetrafluoroethylene, polyvinylidene difluoride, polytetrafluoropropylene, polyhexafluoropropylene, polyvinyl alcohol, polyvinylpyrrolidone, polyethylene glycol, polyethylene oxide, polyglycolic acid, polylactic acid, polydi- oxanone, poly-3-hydroxybutyric acid, poly-4-hydroxybutyric acid, polytrimethylene carbonate, poly-ε-caprolactone, copolymers thereof , Salts thereof, stereoisomers thereof and mixtures (blends) thereof.

In principle, the thread can be left in an unstretched state.

However, in an embodiment which is advantageous in terms of stability, the thread is drawn. Drawing may be performed before or after performing step ii), i. before or after generating the anchoring structures. In other words, it may be provided according to the invention that the intermediate thread is already drawn. In that regard, reference is made mutatis mutandis to the statements made in the context of the second aspect of the invention.

In a preferred embodiment, the anchoring structures, preferably in the form of barbs, are produced by means of cuts in the intermediate thread.

The anchoring structures are produced in a further embodiment only on thread longitudinal sections with a larger thread diameter, in particular on the thread longitudinal sections ai) described in the context of the first aspect of the invention and optionally on sections of the at least one thread longitudinal section b also described in the context of the first aspect of the invention. In a further embodiment, the thread to be produced may be an endless thread, in particular an endless monofilament, or a cut thread, in particular in the form of a monofilament.

However, it is preferred if the thread is only after performing step ii), i. E. after producing the anchoring structures, preferably to obtain the final thread, is cut to length.

In a further embodiment, the thread, in particular after it has been stretched, is subjected to a subsequent treatment, a so-called "post-treatment." As a rule, the thread is tempered in vacuo for this purpose, thereby increasing the crystallinity of the thread and, in particular, the residual monomer content Another advantage that can be achieved by such a treatment is a reduced susceptibility of the thread to shrinkage.

With regard to further features and advantages of the method, as far as possible, reference is made to the statements made within the scope of the present invention aspects.

According to a fourth aspect, the invention relates to a thread having a varying in the longitudinal direction of the thread (changing) thread diameter, which is produced or produced according to one of the inventive method according to the second or third aspect of the invention.

In the embodiments described below, the thread is preferably stretched.

In the case of a needling, the corresponding thread longitudinal section is preferably completely received by a fastening device of a surgical needle. As a result, an improved filling of a needle channel caused by the needle is possible. In general, by combining a thread according to the invention with a surgical needle (or possibly two surgical needles), ratios of needle diameter to thread diameter <1, in particular <1, can be realized. The yarn preferably has at least one yarn longitudinal section a), along which the thread diameter is constant or essentially constant throughout, and at least one yarn longitudinal section b), along which the thread diameter varies (varies), preferably increases or decreases.

An increase or decrease in the thread diameter along the at least one thread longitudinal section b) can be carried out continuously, in particular linearly or substantially linearly, or discontinuously, in particular stepwise.

The at least one thread longitudinal section a) and the at least one thread longitudinal section b) preferably directly adjoin one another.

For anchoring in biological, in particular human and / or animal, tissues, the thread has anchoring structures in another embodiment. The anchoring structures preferably protrude from the thread surface.

The anchoring structures are preferably (only) formed on the surface of the at least one thread longitudinal section a).

According to the invention, it may further be provided that the anchoring structures are additionally also formed on a partial section of the at least one thread longitudinal section b), wherein the partial section preferably directly adjoins the at least one thread longitudinal section a).

The anchoring structures are preferably formed in a unidirectional arrangement in the previous embodiments. In the case of medical use of the suture, the at least one suture longitudinal section b) is preferably for attachment to a surgical needle, i. for a Benadelung, provided.

In a further embodiment, the thread has a thread longitudinal section a-1) along which the thread has a constant diameter di throughout, a thread longitudinal section a ₂ ), along which the thread has a constant diameter d ₂ throughout, and a thread longitudinal section b), wherein the thread longitudinal section b) is preferably arranged between the thread longitudinal sections a- ₁ and a ₂ ). Along the yarn longitudinal section b) varies the thread diameter, wherein the thread diameter preferably increases or decreases. The yarn longitudinal section a-ι) is preferably longer than the yarn longitudinal section a ₂ ). Anchoring structures are preferred in this embodiment on the thread longitudinal section a-ι) and optionally formed on a partial section of the yarn longitudinal section b), wherein the partial section preferably directly adjacent to the yarn longitudinal section ai). Also in this embodiment, anchoring structures preferably have a unidirectional arrangement. In the case of medical use of the thread, it is also preferred if the thread longitudinal section a ₂ ) is provided for a needling.

In an alternative embodiment, the thread has a thread longitudinal section a-ι) of the type described above, two thread longitudinal sections b) and optionally two thread longitudinal sections a ₂ ) of the type described above. The yarn longitudinal section a-ι) is preferably arranged between the two thread longitudinal sections b). The two optionally provided thread longitudinal sections a ₂ ) can each directly adjacent to one of the two thread longitudinal sections b). The two thread longitudinal sections b) may have the same length. The optionally provided thread longitudinal sections a ₂ ) may also have the same length. Preferably, the thread longitudinal section a-ι) is longer than each of the two thread longitudinal sections b) and in particular as each of the two optionally provided thread longitudinal sections a ₂ ). In particular, the thread can have two rows of bidirectionally formed anchoring structures, which are offset by 180 degrees in the circumferential direction of the thread. Preferably, the anchoring structures on the thread longitudinal section a-ι) and optionally on directly on the thread longitudinal section a-ι) adjoining sections of the thread longitudinal sections b) are formed. The anchoring structures are preferably arranged symmetrically to the center of the thread, in particular to the middle of the thread longitudinal section a-1). In the case of medical use of the thread, it is preferred if the thread longitudinal sections b) or the optionally provided thread longitudinal sections a ₂ ) are in each case needled (see FIG. 6 a).

In a further embodiment, anchoring structures which are formed on the at least one thread longitudinal section a) do not differ from each other.

However, anchoring structures of the at least one thread longitudinal section a) may differ from those of the at least one thread longitudinal section b). This applies in particular in relation to anchoring structures, which are formed on a section of the at least one thread longitudinal section b), which is directly adjacent to the at least one thread longitudinal section a). Differences may exist in terms of shape, length, aspect ratio, angle and / or orientation.

In a further embodiment, anchoring structures of the at least one thread longitudinal section b) differ from one another with respect to certain properties, such as For example, shape, length, aspect ratio, angle and / or orientation. If the anchoring structures are produced in the form of incisions, the differences are due to the fact that the depth of the incisions decrease in the direction of decreasing thread diameter.

With regard to further features and advantages of the thread, as far as possible, reference is made to the statements made in the context of the present invention aspects.

A fifth aspect of the invention relates to a thread having a thread diameter varying (varying) in the longitudinal direction of the thread, the thread being a thread core of a stripped core-sheath thread, i. a thread formed or made from a thread having a core-shell structure by removing the shell (stripping). Preferably, the core-sheath structure thread is an intermediate, i. occurring as an intermediate, thread and thus in the inventive thread to a stripped intermediate thread.

The thread has at least one thread longitudinal section a), i. a thread longitudinal section a) or a plurality of thread longitudinal sections a), i. two or more thread longitudinal sections a), along which the thread diameter is constant or substantially constant.

In addition, the thread has at least one thread longitudinal section b), i. a thread longitudinal section b) or a plurality of thread longitudinal sections b), i. two or more thread longitudinal sections b), along which the thread diameter varies (changes), preferably increases or decreases.

The thread diameter can vary along the at least one yarn longitudinal section b) continuously, in particular linearly or substantially linearly, or discontinuously, in particular stepwise, preferably increase or decrease.

An increase or decrease in the thread diameter along the at least one thread longitudinal section b) in the unstretched state of the thread an absolute pitch of 20 mm per cm thread length to 0.01 mm per cm thread length, in particular 15 mm per cm thread length to 0.02 mm per cm thread length, preferred 10 mm per cm of thread length up to 0.02 mm per cm of thread length. With regard to further features and advantages of the thread, as far as possible, reference is also made to the statements made in the context of the present invention aspects.

A sixth aspect of the invention relates to a thread, preferably in the form of a monofilament, having anchoring structures.

The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues. The anchoring structures depend on the thread surface.

The anchoring structures are preferably designed in the form of incisions on the thread and in particular in the form of barbs.

Compared to generic threads, the thread is characterized in particular by having a constant or substantially constant diameter (so-called effective diameter) after producing the anchoring structures, preferably by means of incisions in the thread surface, and after its stretching over its entire length.

In other words, the sixth aspect of the invention relates to a thread having a thread main body and anchoring structures which protrude from the thread main body. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues. The yarn is characterized in particular by the fact that the yarn main body has a (in the longitudinal direction) continuously constant or in contrast to the thread yarn body in the longitudinal direction of the thread continuously formed thread body, ie the thread structures without the anchoring structures substantially constant diameter (so-called effective diameter).

This can be realized with particular advantage an increase and equalization of the linear tensile force of the entire thread. This is in contrast to generic threads, for their production threads are cut with a constant over the entire thread length thread diameter to form anchoring structures. With such threads, the thread longitudinal sections with the anchoring structures have a thread diameter that is significantly reduced compared to the thread longitudinal sections without anchoring structures (effective) thread diameter, which leads to reduced linear and anchoring forces. With regard to further features and advantages of the thread, as far as possible, reference is also made to the statements made in the context of the present invention aspects.

According to a seventh aspect, the invention relates to a hollow fiber, d. H. a thread having a lumen (cavity) bounded by a wall of the thread. The lumen preferably extends in the longitudinal direction of the thread. Preferably, the thread is tubular.

Compared to generic threads, the thread according to the invention is characterized in that it has at least one thread longitudinal section along which the thread wall varies, d. H. along which the thread wall changes.

Due to the varying thread wall, the at least one thread longitudinal section has a gradient running in the longitudinal direction of the thread in relation to the thread lumen.

The wall thickness can vary continuously, in particular linearly or substantially linearly, and / or discontinuously, in particular stepwise, preferably increase or decrease.

A linear or substantially linear increase or decrease in the wall thickness is particularly preferred according to the invention.

Preferably, the increase or decrease of the wall thickness in an unstretched state of the thread is subject to an absolute pitch of 20 mm / cm thread length to 0.01 mm / cm, in particular 15 mm / cm to 0.02 mm / cm, preferably 10 mm / cm to 0.02 mm / cm. The term "absolute slope" is to be understood here as the absolute, that is, independent of the sign, measure for the steepness of a straight line or a curve which characterizes the variation of the wall thickness.

After stretching the thread, however, the values for the absolute slope can be smaller. Thus, in the stretched state of the thread, the increase or decrease of the wall thickness of an absolute pitch of 7 mm / cm thread length to 0.002 mm / cm, in particular 15 mm / cm to 0.04 mm / cm thread length, preferably 4 mm / cm thread length to 0.004 mm / cm thread length, follow.

In a further embodiment, the thread also has at least one thread longitudinal section, along which the thread has a constant or substantially constant wall thickness throughout. In a further embodiment, the thread has a plurality of thread longitudinal sections, along which the wall thickness of the thread varies. With regard to the possible variations of the wall thickness, reference is made to the preceding statements. In addition, the thread may have a plurality of thread longitudinal sections, along which the thread has a constant or substantially constant wall thickness throughout.

In a further embodiment, the thread has an alternating sequence of thread longitudinal sections, along which the wall thickness varies, as well as thread longitudinal sections, along which the thread continuously has a constant or substantially constant wall thickness.

The thread of the invention is particularly suitable for the removal of wound secretions or as a drug or drug depot, wherein the active ingredient or the drug may be embedded for example in a gel.

In another embodiment, the thread has anchoring structures, in particular in the form of barbs. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal tissues. The anchoring structures can thereby be produced, preferably cut, to form openings in the surface of the thread.

With regard to further features and advantages of the thread, in particular of polymers from which the thread may be formed, reference is made, as far as possible, to the statements made in the context of the present invention aspects.

According to an eighth aspect, the invention relates to a method for producing a hollow thread, in particular a hollow thread according to the seventh aspect of the invention. The process comprises the following steps: i) coextruding a core core component and a shell component from a shaping outlet opening of an extrusion device to form an intermediate thread having a core and a core surrounding the core (sheath-core, ie sheath-core structure) ) and ii) removal of the thread core, ie coring of the intermediate thread, wherein, in performing step i), the mass flow rate of the core core component, and preferably the sheath component, is varied (changed) and / or the intermediate thread is withdrawn after exiting the outlet port at a varying (varying) speed.

To perform step ii), d. H. To remove the thread core, both chemical and physical techniques are considered in principle. For example, the thread core can be removed by dissolving in a solvent in which the shell is insoluble. Alternatively, the thread core can be removed by means of a chemical or enzymatic reaction, such as, for example, hydrolysis, in particular ester hydrolysis. For example, if the melting point of the filament core component is lower than the melting point of the sheath component, a suitable physical method of removing the filament core is to melt the filament core by applying heat and allow it to drain to form a lumen extending preferably longitudinally of the filament.

In order to form the additive gradient described in the context of the first aspect of the invention, it is provided in a further embodiment that at least one additive is added in varying amounts to the shell component. With regard to suitable additives, reference is made in full to what has been said in the context of the first aspect of the invention.

In principle, the thread can be left in an unstretched state.

However, in an embodiment which is advantageous in terms of stability, the thread is drawn. Drawing of the thread may take place before or after performing step ii), i. H. Removing the thread core, be made.

In a preferred embodiment, anchoring structures, in particular anchoring structures protruding from the surface of the intermediate thread - or, after carrying out step ii) - anchoring structures projecting from the surface of the cored thread (hollow thread), are produced. The anchoring structures are preferably intended for anchoring in biological, in particular human and / or animal, tissues. The anchoring structures are furthermore preferably produced with the formation of openings through the wall of the thread. Particularly preferably, the anchoring structures in the form of barbs on the surface of the intermediate thread or - after performing step ii) - of the cored out thread produced.

The anchoring structures are preferably produced by means of incisions in the intermediate thread or - after performing step ii) - in the deinked thread.

The anchoring structures can in principle be produced in a stretched or unstretched state of the intermediate thread or, after performing step ii), of the deinked thread. In particular, the anchoring structures can be produced before or after stretching the intermediate thread or - after performing step ii) - of the cored thread.

Preferably, the intermediate thread or, after performing step ii), the de-cored thread is cut before or after stretching to produce the anchoring structures.

Basically, the intermediate thread can be gutted.

In an expedient embodiment, however, the intermediate thread is first cut to length and then the cut-to-length intermediate thread is gutted.

With regard to further features and advantages of the method, in particular threads that can be produced thereby, as far as possible, reference is made to the statements made in the context of the second and seventh aspects of the invention.

According to a ninth aspect, the invention relates to a further method for producing a hollow thread, in particular a hollow thread according to the seventh aspect of the invention. In the process, a filament polymer is extruded by means of a liquid or gaseous support medium from a shaping outlet opening of an extrusion device. The method is particularly characterized in that the mass flow rate of the yarn polymer varies (changed) and / or the mass or volume flow rate of the support medium is varied (changed).

The support medium serves to form a lumen (cavity) preferably extending in the longitudinal direction of the thread.

As a liquid support medium, for example, a polymer melt, a polymer solution (eg polyvinyl alcohol or polyvinylpyrrolidone in water) or lower viscosity liquids such as water, ethylene glycol, diethylene glycol and / or glycerol or mixtures thereof with water, other high-boiling liquid substances or aqueous solutions of mono-, di and / or oligosaccharides and / or amylose. Suitable gaseous support medium are, for example, air, nitrogen, argon and / or helium.

The mass flow rate of the yarn polymer and / or the mass or volume throughput of the support medium can be varied periodically or occasionally. In particular, in an alternating sequence, the mass flow rate of the filament polymer and / or the mass or volume throughput of the support medium can be kept constant and varied or vice versa.

In a further embodiment anchoring structures, preferably for anchoring in biological, in particular human and / or animal, tissues, are produced on the thread.

The anchoring structures are preferably produced by means of incisions in the thread. Here, the incisions can be chosen so deep that breakthroughs are generated by the wall of the thread.

The anchoring structures can furthermore be produced in an unstretched or drawn state of the thread.

With regard to further features and advantages of the method, in particular of the hollow thread to be produced, reference is made, as far as possible, to the statements made in the context of the second, seventh and eighth aspects of the invention.

A tenth aspect of the invention relates to a technical textile which has at least one thread according to the invention, preferably a plurality of threads according to the invention. The technical textile may in principle have a textile structure or be formed from such a structure which is selected from the group comprising woven, knitted, knitted, braided, scrim and combinations thereof.

The technical textile may in particular have a network or be in the form of a network.

Furthermore, the technical textile may have a textile fabric or be in the form of such a fabric.

The technical textile may furthermore have a hollow body structure, in particular a tubular structure, or be present in the form of such a structure.

With regard to further features and advantages of the technical textile, as far as possible, reference is also made to the statements made in the context of the present invention aspects.

According to an eleventh aspect, the invention relates to a medical product which comprises at least one thread according to the invention, preferably a plurality of threads according to the invention.

The medical product is preferably a surgical implant, particularly preferably a medical, in particular surgical, thread (medical, in particular surgical suture).

The medical product can basically have a textile structure or be formed from such a structure, which is selected from the group comprising tissue, knitted fabric, knitted fabric, mesh, scrim, fleece and combinations thereof.

The medical product may in particular have a network or be made as a network.

Furthermore, the medical product may have a textile fabric or be in the form of such a fabric.

The medical product may further comprise a hollow body structure, in particular a tubular structure, or be in the form of such a structure. In a further embodiment, the medical product is selected from the group comprising hernia mesh, prolapse mesh, wound dressing, hemostyptics, vein patch, implant for dura mater replacement, vascular prosthesis, in particular arterial vascular prosthesis, stent graft, stent and occluder.

In a further embodiment, the medical product is intended for use as a nerve guide rail.

With regard to further features and advantages of the medical product, reference is also made, as far as possible, to the statements made in the context of the present invention aspects.

According to a twelfth aspect, the invention relates to a kit, in particular in the form of a needle-thread combination, comprising at least one surgical needle, in particular two surgical needles, and at least one thread according to the invention or a medical product according to the invention.

The at least one needle as well as the at least one thread or the medical product may be spatially separated from each other. Alternatively, the at least one thread or medical product may already be needled.

For the needling, a longitudinal section of the at least one thread or the medical product is preferably completely received by a fastening device of the at least one surgical needle. This makes possible an improved filling of a puncture channel caused by the at least one needle. In general, by combining a thread according to the invention with a surgical needle (or possibly two surgical needles), ratios of needle diameter to thread diameter <1, in particular <1, can be realized.

For threads with bidirectionally formed anchoring structures, a needling is preferably carried out at both ends of the thread.

For threads with undirectionally formed anchoring structures, a needling is preferably carried out at the thread end, which is opposite to the orientation (direction) of the anchoring structures. The other end of the thread is preferably formed either as a loop, stopper or cable tie-like structure, whereby a fixation of the thread dens in biological, especially human and / or animal, tissues as a starting point for a continuous seam is made possible.

The at least one needle may be formed either straight or curved.

Furthermore, the at least one needle may be formed at its expediently pointed end either cutting or provided with a round tip.

In order to accommodate the at least one thread or the medical product, the at least one needle in another embodiment has at its tip end a borehole into which the at least one thread or medical product is inserted and subsequently fixed to the at least one needle, for example by squeezing can be.

With regard to further features and advantages of the medical kit, as far as possible, reference is also made to the statements made within the scope of the present invention aspects description.

Further features and advantages of the invention will become apparent from the following description of preferred embodiments in the form of figures, character descriptions and embodiments and the dependent claims. In this case, individual features can be realized individually or in combination with each other. The preferred embodiments are merely for further explanation and understanding of the invention without limiting it thereto.

In the figures show schematically:

1: an intermediate thread according to the second aspect of the invention, Fig. 2a: a cross section of the thread longitudinal section Ui), Fig. 2b: a cross section of the thread longitudinal section u ₂ ),

3 shows an embodiment of a thread according to the invention, 4 shows a graphic comparison of the thread diameter between a thread according to the invention and a monofilament thread known from the prior art,

5 shows an embodiment of a needle-thread combination according to the invention,

6a shows an embodiment of an unstretched thread according to the invention with incisions,

6b shows another embodiment of a needle-thread combination according to the invention,

FIG. 7 a: an undrawn thread with incisions known from the prior art, FIG.

7b: a needle-thread combination known from the prior art,

8 shows a thread according to the invention with anchoring structures,

9 shows graphically the diameter profile of the thread core of the intermediate thread produced according to Example 1,

10 shows graphically the diameter profile of the monofilament stripped according to Example 2,

1 1: shows graphically the diameter profile of the monofilaments produced according to Example 3,

12 shows graphically outside and effective diameter of the unstretched thread produced according to Example 5 after cutting and stripping,

13 shows diagrammatically the diameter (outer diameter or effective diameter) and top-top spacing of the drawn thread produced according to Example 5,

14a, b: graphically show the outside and effective diameters of the threads produced according to Examples 6 and 7 in the respectively unstretched state, FIGS. 15 a, b: graphically show the diameter (outer diameter or effective diameter) and top-to-top spacing of the threads produced according to Examples 6 and 7 in the respectively stretched state,

FIG. 16: graphically shows the outer diameter and the effective diameter of the comparative example. FIG

8 incised thread in the undrawn state and graphically shows the diameter (outer or effective diameter) and top-top distance of the thread prepared according to Comparative Example 8 in the stretched th state.

figure description

Figure 1 shows schematically a longitudinal section of an intermediate thread 1 according to the second aspect of the invention. The intermediate thread 1 has a thread core 100 and a sheath 200 surrounding the thread core 100. In other words, the intermediate thread 1 has a core-shell structure.

The intermediate thread 1 has a (substantially) constant (outer) thread diameter d.

The intermediate thread 1 can be further subdivided into the thread longitudinal sections Ui), u ₂ ), u ₃ ) and u ₄ ) described below.

The thread longitudinal sections Ui) and u ₃ ) each have a constant shell thickness and a constant thread core diameter. While the cladding thickness of the thread longitudinal sections Ui) is smaller than the cladding thickness of the thread longitudinal sections u ₃ ), the thread core diameter is reversed, ie the thread core diameter of the thread longitudinal sections Ui) is greater than the thread core diameter of the thread longitudinal sections u ₃ ).

Along the thread longitudinal sections u ₂ ) and u ₄ ), both the jacket thickness and the thread core diameter vary. In the embodiment shown in FIG. 1, the jacket thickness along the thread longitudinal sections u ₂ ) increases linearly and the thread core diameter accordingly decreases linearly. In the thread longitudinal sections u ₄ ) it behaves vice versa. There he takes Thread core diameter along the Fadenlangsabschnitte u ₄ ) linearly, whereas the shell thickness of the Fadenlangsabschnitte u ₄ ) decreases linearly accordingly.

The intermediate thread 1 has in the longitudinal direction a preferably recurring sequence of the thread longitudinal sections Ui), u ₂ ), u ₃ ) and u ₄ ).

FIG. 2 a schematically shows a cross section of the yarn longitudinal section U i) shown in FIG. 1, and illustrates that the diameter of the thread core 100 along this yarn longitudinal section is greater than the thickness of the jacket 200.

Figure 2b shows schematically a cross section of the yarn longitudinal section shown in Figure 1 u ₂ ). In the cross section shown, the thickness of the shell 200 is greater than the diameter of the thread core 100.

FIG. 3 schematically shows an embodiment of a thread 100 according to the invention which can be obtained by stripping the intermediate thread 1 shown in FIG.

The thread 100 is preferably stretched before.

The thread 100 has thread longitudinal sections a- ₁ ) with a constant or substantially constant thread diameter di and thread longitudinal sections a ₂ ) with a constant or substantially constant thread diameter d ₂ , where di> d ₂ .

Furthermore, the thread has thread longitudinal sections b), along which the thread diameter varies (changes).

In the embodiment shown in FIG. 3, the thread 100 has a plurality of thread longitudinal sections b), along which the thread diameter decreases (substantially) linearly from di to d ₂ , and several thread longitudinal sections b), along which the thread diameter is (substantially) linearly d ₂ on increases.

Overall, the thread 100 has a recurring sequence of the thread longitudinal sections ai), b) and a ₂ ), resulting in an alternating sequence of thread longitudinal sections with a constant thread diameter and thread longitudinal sections with varying thread diameter.

The thread longitudinal sections b) represent gradient regions with respect to the thread diameter. Figure 4 shows graphically the course of the thread diameter in the longitudinal direction in a thread according to the invention, which was prepared from a thread with a core-shell structure by subsequent removal of the jacket was made (stripped core-sheath thread), represented by curve 1, and at a generic monofilament thread, represented by curve 2.

The ordinate indicates the diameter in mm. On the abscissa, the thread longitudinal position is given in cm.

The graph shows that the thread according to the invention has cleanly formed plateaus, along which the thread diameter is (essentially) constant and at the same time has "sharp" (steep) gradient regions, along which the thread diameter varies almost linearly.

In contrast, the thread diameter in the generic thread shows a more sinusoidal course without recognizable plateau structures and with much flatter gradient areas.

FIG. 5 schematically shows an embodiment of a thread-needle combination 105 according to the invention. The combination 105 is composed of a thread 100 according to the invention and a surgical needle 110. The thread 100 is a thread that can be obtained starting from the intermediate thread 1 shown in FIG. 1 by removing the shell and cutting it to length (before or after removal of the shell).

The thread 100 is composed of a stretched thread longitudinal section ai), a stretched thread longitudinal section b) and a stretched thread longitudinal section a ₂ ). The thread longitudinal sections ai) and a ₂ ) each have a (substantially) constant thread diameter, wherein the thread diameter of the thread longitudinal section ai) is greater than the diameter of the thread longitudinal section a ₂ ).

On the other hand, along the yarn longitudinal section b) the thread diameter changes preferably (substantially) linearly from the diameter of the yarn longitudinal section ai) to the diameter of the yarn longitudinal section a ₂ ) (or vice versa). For attachment to the surgical needle 1 10 of the thread longitudinal section a ₂ ) is inserted into a borehole of the needle 1 10 and fixed, for example by squeezing with the needle end. The outer diameter of the needle 1 10 preferably corresponds (substantially) to the diameter of the thread longitudinal section a ₂ ). According to the invention, it is therefore possible with particular advantage to use a needle thread Diameter ratio of about 1: 1 to realize, which can avoid puncture bleeding, but at least reduce significantly. In contrast, conventional needle-and-thread combinations have needle-to-thread diameter ratios that are significantly larger, typically ranging from 2: 1 to 4: 1.

FIG. 6a schematically shows an embodiment of an unstretched thread 100 '. The thread 100 'is composed of a thread longitudinal section ai), two thread longitudinal sections b) and two thread longitudinal sections a ₂ ). While the thread longitudinal section ai) is arranged between the two thread longitudinal sections b), the thread longitudinal sections b) are each arranged between the thread longitudinal section ai) and one of the two thread longitudinal sections a ₂ ). The thread longitudinal sections a ₂ ) thus form the ends of the thread 100 '.

The thread 100 'has on its surface two rows of bidirectionally arranged anchoring structures 120', which are spaced over cuts 1 18 'from each other. The anchoring structures 120 'are arranged offset by 180 degrees in the circumferential direction of the thread 100'. The anchoring structures 120 'are arranged on the thread longitudinal section a-i) and in each case on a section of the thread longitudinal sections b), which adjoins directly to the thread longitudinal section a-i). By means of a subsequent drawing process, the anchoring structures 120 'can be transferred into anchoring structures 120 protruding from the thread surface, as shown in FIG. 6b.

FIG. 6b shows an embodiment of a needle-thread combination 105 according to the invention. The combination 105 is made of a thread 100 obtainable by stretching the thread 100 'shown in FIG. 6a and two surgical needles 110; 130 composed.

The yarn 100 shown in FIG. 6b is distinguished from generic yarns in particular in that it or the yarn main body 103 has an effective yarn diameter (d _eff ) that is constant over the entire yarn length. Furthermore, the thread 100 is characterized in that the size of the anchoring structures 120, which have emerged from the anchoring structures 120 'of the thread longitudinal section b) of the thread 100', increase in the direction of the thread center, whereas the anchoring structures 120, which consist of the anchoring structures 120 '. the thread longitudinal section ai) of the thread 100 'have emerged, with respect to their size do not differ from each other.

FIG. 7a schematically shows an undrawn thread 10 ', known from the prior art, whose thread diameter is constant over the entire thread length. The thread 10 'has on its surface two rows of bidirectionally arranged anchoring structures 20 ', which are arranged offset in the circumferential direction of the thread by 180 degrees to each other and spaced by cuts 18' from each other. By means of a subsequent drawing operation, the anchoring structures 20 'can be transferred into anchoring structures 20 projecting from the thread surface, as shown in FIG. 7b.

Figure 7b shows a prior art needle-thread combination 5. The combination 5 is made of a thread 10 obtainable by stretching the thread 10 'shown in Figure 7a and two surgical needles 30; 40 composed. In contrast to the thread 100 shown in FIG. 6b, the thread 10 has a significantly larger thread diameter in the region of its ends (outside the longitudinal section with the anchoring structures 20) than the effective thread diameter d _e t _f in the region of the anchoring structures. This in turn requires the use of surgical needles with a correspondingly larger outside diameter. The larger outer diameter forms a larger puncture channel, in which the anchoring structures can anchor less well with a surrounding body tissue. In addition, the linear tensile force along the yarn longitudinal section with the anchoring structures is significantly lower than the linear tensile force along the yarn longitudinal sections without anchoring structures.

FIG. 8 shows schematically an enlarged detail of the thread 100 shown in FIG. 6b. FIG. 8 illustrates once more that the thread 100 has a (substantially) constant effective diameter d _e _f over the entire thread length and also has anchoring structures 120 which (partially ) differ in size from each other.

example part

Example 1 Production of a Core-Sheath Monofilament Having a Thread Core of Poly-p-dioxanone (PDO) and a Jacket of Poly-s-caprolactone (PCL) with an Alternate Core-Sheath Ratio (Intermediate Thread According to the Second Invention Aspect)

The core-sheath monofilament was produced on a bicomponent monofilament extrusion line consisting of a single-screw extruder with two heating zones (core component) and a co-rotating twin-screw extruder with 6 heating zones (jacket) and a metering station for underfeeding the extruder. Both melt streams were conveyed via separate spinning pumps (4 x 0.25 cc / rev) in the spinneret to the spinnerets (4 places) and finally united in the spinneret to the core-shell structure. The nozzles had a diameter of 1, 5 mm at the outlet opening. The core component was via a centric capillary which ends in front of the nozzle outlet opening, while the jacket component annularly surrounded the central capillary. After exiting the die, the bicomponent strands passed through a water bath (T = 20 ° C.) for solidification, were subsequently drawn off via a godet system and wound up by means of a winder. Between the godet system and the winder was a double-axis laser diameter gauge for determining the monofilament diameter.

To obtain the sequence of yarn longitudinal regions Ui) (high core), u ₂ ) (decreasing core), u ₃ ) (low core) and u ₄ ) (increasing core), the control of the bicomponent equipment was modified to allow it to be separated for the spinning polymer of the core polymer and for the spinning polymer of the jacket polymer, in each case a starting value for the spinning pump speed [rpm] and a range (± rpm) within which the spinning pump speeds were varied. The spinning pump speed variation was inverse: by the time the spinning pump speed of the core polymer increased, the spinning polymer spinning speed of the sheath polymer was reduced. Furthermore, a holding time t _{H was} set for both spinning pumps together, during which the spinning pump speeds were kept constant at their maximum or minimum, and a ramp time t _R during which the spinning pump speed either increased from minimum to maximum or dropped from maximum to minimum. The length of the constant regions Ui) and u ₃ ) thus resulted from the holding time, multiplied by the withdrawal speed, the length of the varying regions from the ramp time, multiplied by the withdrawal speed. For this experiment, the parameterization was as follows:

Holding time t _H : 2 s Ramp time t _R : 1 s Pulling speed: 1, 4 m / min Spinning pump Core: 3.2 rpm ± 1, 2 rpm Spinning pump jacket: 3.2 rpm ± 1, 2 rpm Temperature profile core extruder: 140 ° C / 160 ° C Temperature profile jacket extruder: all zones 190 ° C

Spinning head temperature: 190 ° C The diameter of the bicomponent bicomponent monofilament was essentially constant at 1, 196 mm ± 0.025 mm over the entire run time.

In order to be able to make initial statements about the quality (precision of the constant diameter ranges and steepness of the varying regions) of the diameter profile of the core component, cross-sections were made at a distance of 1 cm along the longitudinal axis of the thread and measured microscopically.

The obtained diameter profile of the thread core over the longitudinal axis is shown graphically in FIG. The ordinate shows the diameter in mm, the abscissa shows the length of the thread in cm. As can be seen, despite the extremely short holding and ramping time, bicomponent technology, which ensures consistent overall mass flow rate, forms a very precise diameter profile with clean imaging of the plateaus and gradients.

Example 2: stripping of the intermediate monofilament from example 1 (according to the second aspect of the invention)

The sheath polymer PCL of the intermediate monofilament of Example 1 has a melting point of 60 ° C and is well soluble in toluene, while the core polymer PDO is insoluble in toluene and has a melting point of 105 ° C to 110 ° C. These differences in the behavior of both polymers were used to detach the cladding from the filament core at T = 65 ° C in toluene. This process can be carried out continuously in heated solvent baths, which passes through the intermediate thread, but also discontinuously in the cut-to-length state. For simplicity, the discontinuous process was chosen here: For this purpose, 50 cm long pieces of thread were placed for 10 min in toluene at T = 65 ° C and then washed in a second vessel in toluene at room temperature, stripped off the solvent and the pieces of thread dried overnight. A subsequently measured NMR spectrum contained no signals from PCL. The stripping of the intermediate thread was thus completely.

The stripped monofilament was characterized microscopically with respect to the diameter course on three pieces of thread, wherein the starting position of the investigation was chosen arbitrarily. In Figure 10, the diameter profile of the stripped Monfilaments is shown graphically. The ordinate shows the diameter in mm, the abscissa shows the length of the thread in cm. FIG. 10 shows an excellent design of the diameter profile under precise formation of the plateaus and sharp and reproducible formation of the gradients (gradient approx. 0.2 mm / cm).

In contrast, the gradient monofilament prepared according to Example 3 below using monocomponent technology shows a rather sinusoidal diameter profile due to the viscoelastic behavior of the polymer and the changing mass throughput and thus variable spinning distortions.

Example 3: Monocomponent monofilaments of variable diameter PDO

A overnight dried at 80 ° C in vacuo (6 mbar) PDO polymer was on a single screw extruder with two heating zones (T = 140 ° C / 160 ° C) with variation of the spinning pump speed with a monocomponent spinneret to monofilaments with along the Thread longitudinal axis varying diameter sections processed under the following parameterization:

Tab. 1: Parametrization of the gradient mono-component extrusion from Example 3

In contrast to Example 1, no second polymer component (sheath) was coextruded, which is why, in contrast to the intermediate bicomponent thread of Example 1, the extruded strand did not have a substantially constant outer diameter, but, as in the stripped thread of Example 2, a thread with varying Diameter along its longitudinal axis trained. The diameter profile of the extruded strands could be determined directly with a double-axis laser measuring device and is graphically in the Figure 1 1 shown. The ordinate shows the diameter in mm, the abscissa shows the length of the thread in cm.

It can be seen that, with monocomponent technology, with short thread longitudinal sections aimed for, in contrast to example 2 produced by coextrusion, only sinusoidal courses (example 3a) can be realized rather than the formation of plateaus. Only when significantly increasing the holding time of the spinning pump speed (Example 3b) succeeded in the formation of plateaus, the diameter profile was far from being as accurate as in the thread produced according to Example 2. For numerous medical applications, in particular for a surgical suture and especially in the production of suture material with anchoring structures, but on the one hand precise diameter courses are required, and on the other it is advantageous if the plateaus and the gradient on as short a thread section are formed. This applies more and more to applications in which, in order to increase the tensile strength and to reduce elongation, a stretching operation has to be carried out in which the yarn longitudinal sections are elongated by the drawing factor.

Example 4: Drawing, lengthening and needling of the stripped monofilament

Example 2 as a stitch channel occluding monofilament

The stripped piece of thread from example 2 was stretched in a discontinuous stretching device, consisting of a heated oven, a stationary and a mobile clamp, at T = 80 ° C to five times its original length. By means of a double-axis laser diameter measuring device, the transition region from a thread longitudinal section b) to a thread longitudinal section a ₂ ) was determined and from here the thread was cut so that 0.5 cm from the thread longitudinal section a ₂ ) remained. On the other thread side of the range was determined in which a thread longitudinal section a-ι in the thread longitudinal section b) passed. The thread was there cut off at the end of the thread longitudinal section a-ι), so that a total length of the thread of 30 cm resulted. The area of the thread longitudinal section a-ι) in the stretched state took 20 cm and that of the yarn longitudinal section b) in the stretched state 10 cm of the thread piece. In the region of the yarn longitudinal section a ₂ ), the diameter of the drawn yarn was 0.30 mm, which corresponds to a commercial over-sorting of the strength USP 3-0 in monofilaments. In the range of the thread longitudinal section a-ι) the diameter was 0.49 mm, this corresponded to a USP 1. The linear tensile strength in the region of the thread longitudinal section a-ι), which is to provide the wound closure later, was 72 N at an elongation at break of 42% , The thread was cut with a needle (length 26 mm, needle diameter 0.58 mm, drill channel diameter 0.33 mm, taper point) by means of a Quicky Tach III needling device. needles. The needle-to-thread diameter ratio was 1.18, when the thread diameter used was that of the thread longitudinal section ai) to be used for wound closure. As a comparison thread, a stretched PDO monofilament with a constant over the entire thread length diameter of 0.49 mm with a needle (length 36 mm, needle diameter 0.98 mm, drill channel diameter 0.55 mm, taper-point) was needled. This resulted in a needle-to-thread ratio of 2.0. It should be noted that the needles used were typical needles for thread sizes USP 3-0 and USP 1.

For stitches in the cardiovascular area, the puncture channel bleeding is a major problem. It results from the large, formed by the needle diameter puncture channel, which can not be nearly filled in suture materials on the market by the smaller thread diameter. For the measure of the leakage of a seam, therefore, the ratios of the cross-sectional area of the needle to the cross-sectional area of the thread must be used. In Example 4 according to the invention, this ratio was 1.39, while the comparative example of starch USP 1 had a ratio of 4.0.

Both needled monofilament sutures were subjected to the following test:

A stand-cylinder filled with water was closed with a latex foil, through which the comparative suture was drawn in previously by means of the surgical needle of the invention and in another experiment. The thread according to the invention was pulled in so far that the thread longitudinal section a-i) was in the region of the stitch channel of the latex film. Now the cylinder was turned over so that the water column stood on the membrane. The leaked water through the branch channel was collected in a second vessel over a period of 1 minute. While in the thread according to the invention only 2 ml leaked in the observed period, it was 18 ml in the comparison thread. The surgical suture according to the invention thus reduces the extent of the puncture channel bleeding in an efficient manner. In a needling with cutting needles even an even greater difference is to be expected, since the membrane is not only displaced as a "vessel wall", but is cut by means of the cutting of the needle, whereby an effectively larger channel is formed.

Example 5 Surgical suture with unidirectional anchoring structures, formed by cutting into the intermediate thread produced according to Example 1, followed by stripping and subsequent drawing

The intermediate thread of Example 1 was cut to 25 cm so that the middle of the thread longitudinal section ai) was in the middle of the thread. The cuts for the production of the anchoring structures were carried out on an automated plant with control of the individual process steps, which consisted essentially of the following elements:

1 . Motorized rotatable Fadeneinspannvorrichtung, wherein the receptacle was stationary at one end of the thread and ran at the other end of the thread on a carriage and was acted upon by a gravitational force to provide a thread tensioning force.

2. A cutting abutment in the form of a groove in which the clamped thread is guided under tension. The groove depth was about 60% of the thread diameter (40% of the thread diameter looked up out of the groove) and the groove width about 120% of the thread diameter, so that the thread could be rotated freely in the groove after each individual incision.

3. The recording of the actual cutting device, which was adjustable in terms of cutting angle in the range of 15 ° to 60 °.

4. The base plate of the cutting device, which ran on a carriage and whose position with respect to the thread longitudinal axis by means of a fine thread screw was precisely adjustable.

5. The cutting device itself, which consisted of a fast linear motor handling (simplified axis) and at the lower end of a blade holder was mounted with clamped blade. The axis allowed an accuracy of the cut length of 20 μηη. The plant included two oppositely positioned cutting devices. To produce a unidirectional thread with anchoring structures, a cutting device was sufficient to make a bi-directional thread (the barb tip of both barb sections looked towards the center of the thread) both cutters were needed.

6. A macroscope with camera for transferring the image to an evaluation software (image processing) of a connected PC. The macroscope was used to adjust the cutting depth and to check the cutting distance and the cutting angle.

After setting the cutting angle (here 25 °) and after adjusting the depth of cut to 20% of the total thread diameter (this thread with a total outer diameter of 1, 196 mm and a shell thickness of 0.098 mm this corresponded to the thread core diameter in the region of the yarn longitudinal section ai) (di) an effective maximum depth of cut of 14%, wherein the depth of cut in the region of the yarn longitudinal section b) decreased to 0%, based on the core diameter, since the cladding thickness in the area of the thread length section a ₂ ) was slightly more than 20% of the total diameter and the core was not cut in this area.

To make the thread, the following sequence of process steps was required

1 . Approaching the middle of the thread longitudinal section a-i)

2. Set the (first) incision

3. Rotate the thread material by 180 ° about its longitudinal axis by means of the rotatable Fadeneinspannvorrichtung

4. Feed the cutting device by 0.2 mm (20/100 mm) along the longitudinal axis of the thread

5. Repeat steps 2 to 4 to a total of 171 cuts (this covered a total of 34 mm of thread along its longitudinal axis)

The thread was examined microscopically following the cutting and subsequently peeled off from PCL analogously to Example 2. Subsequently, the incised thread was measured microscopically with respect to its outside diameter d _a and the effective diameter d _e t _f remaining between the incisions of the opposite rows of cuts. The result is shown graphically in FIG. 12, wherein the ordinate represents the diameter in mm and the abscissa shows the longitudinal thread position in cm. From Figure 12 it can be seen that both the outer diameter and the effective diameter in the region of the thread longitudinal section ai) (up to about 2.0 cm from the center of the thread longitudinal section ai) removed) remained substantially constant, which requires that the depth of cut in remained essentially constant in this area. The behavior was different in the region of the yarn longitudinal section b) (distance from the middle of the yarn longitudinal section ai) greater than 2.0 cm): Here, the outer diameter decreased linearly, while the remaining effective diameter remained constant, indicating that the depth of cut in this area wished practically zero.

In order to set up the anchoring structures and to increase the linear tensile strength of the thread, it was stretched discontinuously as described in Example 4. Due to the cuts, however, only a stretch ratio of 3.75 could be used here because Otherwise would have come to the thread break. As described in Example 4, this thread was cut to length so that only the entire, provided with anchoring structures half thread section ai), provided with decreasing anchoring structures thread longitudinal section b) and about 5 cm of the thread longitudinal section a ₂ ) (without anchoring structures) remained. The total length of the thread was about 20 cm. The linear tensile strength of the yarn was 32 N with a breaking elongation of 29%. The area of the thread longitudinal section ai), which is thick in diameter and not provided with anchoring structures, can be used in threads with unidirectional anchoring structures to produce a loop, for example by ultrasonic welding, by means of which the seam beginning of such a thread can be fixed in the fabric. In the region of the thread longitudinal section a ₂ ) the thread diameter was 0.33 mm (USP 2-0), in the region of the thread longitudinal section ai) without anchoring structures the diameter was 0.51 mm (USP 1).

The outside diameter in the regions free of anchoring structures and the effective diameter described above between the rows of anchoring structures, both of which were guided under a diameter, were measured microscopically. The aim was to adjust the effective diameter of the thread longitudinal section ai) in approximately the diameter of the thread longitudinal section a ₂ ). Furthermore, the distance between the tips of two adjoining anchoring structures arranged on different rows (ie on the opposite side of the thread surface) was measured. This so-called top-top distance is a measure of the size of the anchoring structures. If the top-top distance approaches that of the diameter (outer diameter or effective diameter), the anchoring structures are only minimally pronounced:

It can be seen from FIG. 13 that the goal of maintaining the effective diameter in the regions with anchoring structures approximately at the level of the yarn longitudinal section a ₂ ) (from about 14 cm from the middle of the yarn longitudinal section ai)) has been achieved, which has not been the case If one had cut into a monofilament with constant diameter everywhere. If this were done using the same cut configuration with an effective depth of cut of 14% in a monofilament having a constant diameter of 1.0 mm, the effective diameter in the anchoring structure-containing area would have been about 0.35 mm after drawing, but the diameter would have been The areas without anchoring structures would be approximately 0.52 mm, which in turn would require a larger diameter needle and would result in smaller anchoring forces in the human or animal tissue. By virtue of the smaller effective diameter compared to the rest of the thread area, such conventional anchoring structures are more susceptible to breakage in the area containing anchoring structures. Examples 6 and 7 Surgical sutures with unidirectional anchoring structures formed by incising into the stripped thread according to Example 2 with subsequent drawing and needling

The stripped thread from Example 2 is cut to 25 cm so that the middle of the thread longitudinal section a-ι) was in the middle of the thread. As described in example 5, two different sectional configurations were produced in the unstretched state:

Tab. 2: Parameterization of the cutting in of Examples 6 and 7

The course of the outer and effective diameters in the incised but unstretched state of both examples are shown graphically in FIG. 14a (example 6) and FIG. 14b (example 7). The ordinates each show the diameter in mm and the abscissa each show the longitudinal thread position in cm. In essence, the graphics shown in Figures 14a and 14b show a similar course.

Subsequently, a stretching was carried out analogously to Example 5. The result of the microscopic examination of the drawn threads with anchoring structures is shown graphically in FIG. 15a (Example 6) and FIG. 15b (Example 7), wherein the ordinates each show the diameter or the top-top spacing in mm and on the abscissa in each case the thread longitudinal position is shown in cm.

In particular, in the range 15 cm from the center of the thread longitudinal section a-ι) removed increase in the diameter d of Example 7 is due to the fact that only a depth of cut of 12% with respect to the maximum diameter (di in the range a-ι) and selected thus only Approximately half of the length of the thread b) was provided with cuts (the rest of the cuts went into the void, as the depth of the blade did not reach down to the decreasing diameter). The difference between the core diameter di of the yarn longitudinal section a-ι) and d _{2 of} the yarn longitudinal section a ₂ ) in the intermediate or stripped yarn should therefore ideally be selected such that it was twice the intended cutting depth in terms of percentages. As in Example 5, the not provided with anchoring structures half of the stretched filament longitudinal section a-ι) can be used to produce from her a loop, for example by ultrasonic or high-frequency welding, which serves as a fixation point in the tissue at the beginning of the seam by the needle after the first stitch is passed through them.

The threads with anchoring structures produced according to Examples 6 and 7 were provided with the following needles at their thin end of the thread longitudinal section a ₂ ) (d ₂ ~ 0.32 mm):

Thread with Anchoring Example 6 Example 7

structure

Drawing temperature [°] 80 80

Draft ratio 3.75 3.75

Linear tensile strength [N] 30,9 36,2

Strength with respect to d2 361 450

[N / mm ² ]

Needled Thread Example Example 6b Example Example 7b

6a 7a

Needle radius 0 (linear) 180 0 (linear) 180

Diameter needle [mm] 0,68 0,68 0,68 0,68

Ratio Needle 1, 36 1, 36 1, 36 1, 36

Thread diameter d1 (without

Anchoring structure)

Length needle [cm] 40 26 40 26 Drilling channel diameter 0.40 40 0.40 40 [mm]

Needlepoint Taper- Taper-point Taper- Taper-point

point point

Tab. 3: Needling of Examples 6 and 7

The results of the human or animal tissue anchorability study of the sutures prepared according to Examples 6 and 7 compared to a suture having constant diameter monofilament anchoring structures (Examples 8 and 9) can be found in Examples 8 and 9 below ,

Examples 8 and 9: Comparative Examples to Examples 6 and 7: Threads having anchoring structures of monofilaments of the strengths USP 0 and USP 3-0 without diameter gradient including needling.

Two PDO spun yarns (unstretched) without diameter gradient with the diameters d = 0.98 mm and d = 0.68 mm were cut with the machine described in Example 5 as follows from the middle of the thread and subsequently drawn:

Example 8a Example 8b Example 9a Example 9b

Diameter Spinnfa 0.98 0.98 0.68 0.68

the [mm]

Cutting angle [°] 25 25 35 35

Depth of cut [in% of d] 17 17 17 17

Cutting distance [mm] 0.20 0.20 0.07 0.07

Angular offset [°] or 180 (2) 180 (2) 180 (2) 180 (2)

Number of rows (in

brackets)

Drawing temperature [°] 80 80 80 80

Deferred ratio 3.75 3.75 3.75 3.75 Linear breaking force [N] 36.3 36.3 17.3 17.3

Strength with respect to 201 201 202 202

Diameter outside

Barb area

[N / mm ² ]

Diameter outside 0.48 0.48 0.33 0.33

Barb area [mm]

Effective diameter in 0.26 0.26 0.19 0.19

Barb area [mm]

Needle radius 0 (linear) 180 0 (linear) 180

Diameter needle 0.83 0.78 0.68 0.68

[Mm]

Ratio Needle 1, 73 1, 63 2.06 2.06

Thread diameter (without anchoring structure)

Length needle [cm] 40 36 40 26

Drilling channel diameter 0.55 0.55 0.40 0.40

[Mm]

Taper point Taper point Taper point Taper point Taper point

Tab. 4: Parameterization during the cutting, drawing and needling of monofilaments with constant diameter (Comparative Examples 8 and 9)

The course of the outside and effective diameters of the incised thread cut in accordance with Example 8 is shown graphically in FIG. 16. On the ordinate the diameter is shown in cm and on the abscissa the thread longitudinal position in cm.

After stretching, the course of the diameter and of the top-top distance shown in FIG. 17 was formed, wherein d is in the region of the anchoring structures for the effective diameter and outside this range stands for the outside diameter. The Benadelung took place here in the range from 15 cm from the center of the thread and required - in contrast to the inventive examples 6 and 7 - a needle with significantly larger hole and thus also a much larger outer diameter. The non-inventive thread according to Example 8 would have to be classified as USP 1 due to its large outer diameter, but because of its low effective diameter in the anchoring structures, the linear tensile force was only 36 N and thus did not meet the USP limits even taking into account the market discount for self-anchoring sutures , This applies analogously to the thread produced according to Example 9, which represented a suture USP 2-0 due to its outer diameter, but its linear tensile force was almost 2 times lower than the linear tensile force of the threads prepared according to Examples 6 and 7, the also classified as USP 2-0.

Example 10 Investigating the anchoring capacity

In order to examine the anchoring capacity in human and / or animal tissue, which is important for sutures with anchoring structures, for the threads produced according to Examples 6 to 9, an approximately 30 mm thick piece of pork belly without rind was used. In the samples with linear, ie straight needle, the needle was manually punched from the top of the pork belly to the bottom (distance about 30 mm) and the thread so far (retracted in the sliding direction of the anchoring structures) that the center of the anchoring area in the tissue was placed. Now, the needle end opposite end of the thread was clamped in the jaws of a universal testing machine from. Zwick and moved at a speed of 80 mm / min in the anchoring direction of the anchoring structures, the maximum anchoring or pull-out force was determined.

For the samples with radial needles, the needle was placed approximately at right angles to the top of the pork belly and pierced through the tissue according to the needle radius so that the needle emerged again at the top of the pork belly. After emergence of the needle, the suture was drawn in so far that the center of the area of the anchoring structures was localized in the tissue. The path or the length of the thread in the tissue corresponded approximately to the needle length. Now, the needle end opposite end of the thread was clamped in the jaws of a universal testing machine from. Zwick and moved at a speed of 80 mm / min in the anchoring direction of the anchoring structures, the maximum anchoring or pull-out force was determined.

As expected, it was found that the radial pull-out force was greater than the linear pull-out force of the thread from the tissue, since in the inner radius of the radial region a more frictional contact between the anchoring structures and the tissue existed. USP pull-out force linear [N] Pull-out force radial

[N]

Example 6 2-0 12.7 15.8

Example 7 2-0 10.5 21, 7

Example 8 1 8.8 17.9

Example 9 2-0 4.2 8.8

Tab. 5: Anchoring forces of the threads with anchoring structures in the pork belly (30 mm

Thickness)

The threads according to the invention with anchoring structures of Examples 6 and 7 showed in comparison to the inventive thread according to Example 9, which was also classified as a thread USP 2-0 strength, increased by at least a factor of 2 anchoring force in the tissue, which was essentially based on it in that their thread diameter in the region outside the anchoring structures substantially corresponded to the remaining effective diameter in the regions with anchoring structures and therefore a thinner needle with a smaller ratio of needle to thread diameter could be selected. Furthermore, the inventive threads according to Examples 6 and 7 with linear tensile forces of 30, 9 N and 36.2 N substantially met the requirements of USP on 2-0 thread size, while the thread not according to the invention a linear tearing force of only 17.3 N showed.

Example 1 1: Suture with unidirectional anchoring structures formed by cutting into the monocomponent gradient monofilament of Example 3a with subsequent stretching

The monocomponent monofilament from Example 3a with a maximum thread diameter of 1.10 mm and a minimum thread diameter of 0.93 mm was according to Example 7 (cutting angle 35 °, cutting depth of 12% based on the maximum diameter, cutting distance 0.10 mm) with Provided incisions. Since the thread longitudinal sections could not be formed as short as with the bicomponent technology, an average of 2,000 cuts, starting from the middle of the range of a-ι), had to be chosen, as large as possible of b) (decreasing diameter) to be able to cut. Due to the sinusoidal diameter profile of the monofilament of Example 3 was obtained in contrast to Example 7 and Figure 14 b no area with substantially constant depth of cut: Rather, it fell over almost the entire length of the center of a-ι) almost to reach the minimum diameter steadily from to 0%, only the effective diameter remained in the Essentially constant. After stretching analogously to Example 7, a similar picture resulted for the top-top distance: In contrast to Example 7 and Figure 15 b, no area was obtained in which the top-top distance remained substantially the same size, but rather this fell steadily over a length of now 80 cm, analogous to the depth of cut.

Example 12: Hollow filament with variable lumen and a substantially constant outer diameter

A bicomponent extrusion was carried out analogously to Example 1, except that polypropylene was chosen here as the sheath polymer and polyethylene glycol as the core polymer. The temperature of the spinning head was 190 ° C and the ramp time was varied from 1 s to 20 s, whereby threads with different lengths of thread sections b) could be produced. After cutting the unstretched threads so spun, the core polymer was dissolved out in a heated water bath (T = 70 ° C), which hollow fibers could form with hose structures, the longitudinal sections b) with gradients with respect to the lumen size and the jacket thickness and longitudinal sections a-ι) and a ₂ ) having a substantially constant lumen and constant shell thickness, wherein the shell thickness MD2 in the range of a ₂ ) is greater than the shell thickness MD1 in the area a-ι). The diameter of the lumen is reciprocal to the shell thickness. Instead of the core polymer, a liquid or gaseous component can also be used as support medium with variable mass or volume throughput during the extrusion. The outer diameter of the hollow fibers thus formed is substantially constant. The hollow fibers can be stretched to increase their strength. Hollow fibers with a relatively long ramp time have long longitudinal sections b) with preferably linearly changing lumen diameter. Such hollow fibers can serve to either remove wound secretions via capillary effects or to transport fluid additives such as medicaments into the tissue. On a technical level, because of their capillarity, these threads can serve to transport water or other fluid media. In a further embodiment, these hollow body filaments in the region of a-1) (smallest shell thickness) can be cut so far that breakthroughs are generated by the jacket in this area. The cuts can be made either in the unstretched or in the stretched state. In this case, anchoring structures can form on the surface of the hollow fibers in addition to the openings. These hollow fibers can serve either as drainage or as a medication aid (eg local release of anti-inflammatory drugs or cytostatic drugs), whereby the anchoring structures provide a spatially exactly desired fixation in the body Tissue can be achieved. In the technical field, such hollow fibers can be used for spraying or atomizing liquids, which are introduced under pressure into the hollow thread. In a further embodiment, these hollow fibers may serve to form alternately turbulent and laminar flows in fluid media which they flow through. This can serve to homogenize dispersions or emulsions. Furthermore, the areas of large lumens can serve as a drug or drug depot, wherein the drug or drug can be embedded for example in a gel.

Claims

claims

1 . Thread with a varying thread diameter, comprising a) thread longitudinal sections along which the thread diameter is constant or substantially constant, and b) at least one thread longitudinal section along which the thread diameter varies, characterized in that the thread longitudinal sections a) are longer than the at least one thread longitudinal section b).

2. Thread according to claim 1, characterized in that the thread diameter along the at least one thread section b) linear or substantially linear increases or decreases.

3. Thread according to claim 2, characterized in that the increase or decrease in the thread diameter along the at least one thread longitudinal section b) in the unstretched state of the thread an absolute pitch of 20 mm / cm to 0.01 mm / cm, in particular 15 mm / cm to 0.02 mm / cm, preferably 10 mm / cm to 0.02 mm / cm, follows.

4. Thread according to one of the preceding claims, characterized in that the thread longitudinal sections a) comprise: a-ι) at least one thread longitudinal section, along which the thread continuously has a constant or substantially constant thread diameter di, and a ₂ ) at least one thread longitudinal section along which the yarn has a constant or substantially constant diameter d ₂ throughout, where

5. Thread according to one of the preceding claims, characterized in that the thread has a plurality of thread longitudinal sections b) along which the thread diameter varies, in particular linearly or substantially linearly increases and / or decreases.

6. Thread according to one of the preceding claims, characterized in that the thread preferably from the thread surface protruding anchoring structures, in particular in the form of barbs, for anchoring in biological, especially human and / or animal, tissues.

7. Thread according to claim 6, characterized in that the anchoring structures on thread longitudinal sections a-ι) with a constant or substantially constant thread diameter di, but not on the thread longitudinal sections a ₂ ) with a constant or substantially constant thread diameter d ₂ , wherein the di d ₂ is, are formed.

8. Thread according to one of the preceding claims, characterized in that it is the thread around the thread core of a stripped core-sheath thread.

9. A method for producing a thread, in particular according to one of the preceding claims, comprising the following steps: i) coextruding a thread core component and a shell component from a shaping outlet opening of an extrusion device to form an intermediate thread with a thread core and a surrounding coat of the thread core and ii ) Removing the jacket from the thread core, characterized in that when performing step i) the mass flow rate of the thread core component and preferably the shell component varies and / or the intermediate thread is withdrawn after exiting the outlet opening at a varying speed.

10. The method according to claim 9, characterized in that for varying the mass flow rate, the rotational speed of a responsible for the extrusion of the thread core component spinning pump and / or the speed of a responsible for the extrusion of the shell component spinning pump can be varied.

1 1. A method according to claim 9 or 10, characterized in that the sum of the mass flow rates of the yarn core and sheath component is kept constant or substantially constant.

12. The method according to claim 9 or 10, characterized in that for varying the withdrawal speed, the rotational speed of a responsible for the withdrawal of the intermediate thread godet is varied.

13. The method according to any one of claims 9 to 12, characterized in that anchoring structures, preferably in the form of barbs, for anchoring in biological, especially human and / or animal, tissues are formed by means of incisions in the intermediate thread, the depth of cut is greater as the thickness of the jacket.

14. The method according to any one of claims 9 to 13, characterized in that anchoring structures, preferably in the form of barbs, for anchoring in biological, in particular human and / or animal, tissues are formed by means of incisions in the stripped thread core.

15. Thread with a varying thread diameter, in particular produced or producible by a method according to one of claims 9 to 14, characterized in that it is a thread core of a stripped core-sheath thread in the thread.

16. A medical product, preferably surgical suture material, comprising at least one thread according to one of claims 1 to 9 or at least one thread according to claim 15.

17. A medical kit, in particular in the form of a needle-thread combination, comprising at least one surgical needle and at least one thread according to one of claims 1 to 9, at least one thread according to claim 15 or a medical product according to claim 16.