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Publication numberWO1996013434 A1
Publication typeApplication
Application numberPCT/FI1995/000562
Publication dateMay 9, 1996
Filing dateOct 11, 1995
Priority dateOct 11, 1994
Publication numberPCT/1995/562, PCT/FI/1995/000562, PCT/FI/1995/00562, PCT/FI/95/000562, PCT/FI/95/00562, PCT/FI1995/000562, PCT/FI1995/00562, PCT/FI1995000562, PCT/FI199500562, PCT/FI95/000562, PCT/FI95/00562, PCT/FI95000562, PCT/FI9500562, WO 1996/013434 A1, WO 1996013434 A1, WO 1996013434A1, WO 9613434 A1, WO 9613434A1, WO-A1-1996013434, WO-A1-9613434, WO1996/013434A1, WO1996013434 A1, WO1996013434A1, WO9613434 A1, WO9613434A1
InventorsJari Ruuttu
ApplicantDatalab Oy
Export CitationBiBTeX, EndNote, RefMan
External Links: Patentscope, Espacenet
A method for shrinking a shrink film
WO 1996013434 A1
Abstract
The object of the invention is a method for shrinking a shrink film (1). The method is characterized in that energy is generated in the shrink film (1) by supplying a resistive area in the shrink film with electric power; an area in the shrink film absorbing microwaves with microwaves; or similar impulses having a direct impact on the shrink film.
Claims  (OCR text may contain errors)
Claims
1. A method for shrinking a shrink film (1), in which energy is produced in the shrink film (1) by supplying a resistive area (2,3,6) in the shrink film with electric power, an area in the shrink film absorbing microwaves with microwaves, or other similar impulses which have a diiect impact on the shrink film, characterised in that resistive prints are made on the surface of the shrink film, for instance by using the offset method.
2. A method as claimed in claim 1, characterised in that the shrink film is multi- layered, one of the layers being resistive.
3. A method as claimed in claim 1 or 2, characterised in that the resistive area is supplied with low- voltage current, for instance 12 to 24V.
4. A method as claimed in any of the preceding claims, characterised in that the shrink film (1) has been provided with contact surfaces (4, 5), to which current is conducted and from where it passes on into the resistive area.
5. A shrink film (1) designed for packaging various products, the shrink film being apt to be fitted around the product by shrinking, and the shrink film (1) com¬ prising a totally or partly resistive area, which is electrically heated and produces the shrinking effect, characterised in that the shrink film comprises various resisti¬ ve areas (6), which shrink in different and predetermined ways under the effect of the same electric current.
Description  (OCR text may contain errors)

A method for shrinking a shink film

This invention relates to a method for shii king a shrink film.

Nowadays shrink films are shrunk by using hot-air blowers, by radiating heat, or by heating in furnaces. However, all these prior-art methods have the drawback of involving very high energy consumption. Also, the time required for the shrink film to shrink as desired depends on the heat, i.e. the energy. Slirinking usually takes several seconds. In view of this, the object of the invention is to eliminate the draw- backs mentioned above. The method of the invention is characterized in that energy is generated in the shrink film by supplying a resistive area in the shrink film with electric power; an area in the slirink film absorbing microwaves with microwaves; or other similar impulses having a direct impact on the shrink film. Tests have indicated that shrink film which has been made resistive is shrunk in 200 ms with a 12V voltage and 1 A current, into a state that would require several seconds in a furnace, which besides, has 20-fold power consumption compared to the invention. The invention generates energy directly on the right spot, without causing any waste heat, in contrast to all prior-art methods.

One embodiment of the invention is characterized in that the shrink film is made resistive by admixing a resistive substance in the film proper, so that the shrink film itself becomes either totally or partly resistive. With this proceeding, the shrink film will shrink either in specific areas ar all over, exactly as desired.

Other embodiments of the invention are described in the dependent claims.

The invention will be described below with reference to the accompanying drawings, in which

Figure 1 shows a shilnk film which is resistive in itself, Figure 2 shows a slirink film provided with surface resistances,

Figure 3 shows a shrink film provided with a resistance coating produced for instance by offset printing,

Figure 4 shows the shrink film when opened,

Figure 5 shows the shrink film bent into a cylindrical shape, Figure 6 shows the shrink film fitted around a pile of coins and

Figures 7 and 8 show various shrink film embodiments. The shrink film in figure 1 has been produced by admixing a resistive substance in the plastic material 1, the resistive substance being heated under the effect of elec¬ tric power, and by slrrinking the shrink film uniformly. In figure 2, surface resistan¬ ces 2 have been attached to the surface of the film 1. In figure 3 resistive prints 3 have been made on the surface of the shrink film by using the offset method. The shrink film may optionally be multilayered, and in that case one of the layers is resistive. The resistive area is supplied with low- voltage current, for instance 12 to 14V. The figure illustrates direct voltage, however, alternating voltage is equally possible. The shrink film 1 is provided with contact surfaces 4, 5, to which current is conducted and from where it passes on to the resistive area. Figure 7 shows the resistive area 6 focussed in the centre of the shrink film. This particular spot will be heated at a considerable higher rate and will shrink to a larger extent than the remai¬ ning area. At the edge of the shrink film a glue surface 7 is provided, which joins the edges of the shrink film, around a pile of coins for instance, as illustrated in figure 6. In shrinking, the ends of the shrink film bend to overlap, as indicated by arrows 8.

The design of the device is not shown in detail here, because it consists of simple components known per e, and furthermore, it is appreciably cheaper than the furnace option cited by way of example.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
WO1984003872A1 *Apr 6, 1984Oct 11, 1984Scan Coin AbA method in packaging coins and a film of plastic material for practising the method
US4323607 *Aug 23, 1979Apr 6, 1982Ube Industries, Ltd.Heat shrinkable covers
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
WO2001095753A1 *Jun 15, 2001Dec 20, 2001Ci4B LimitedA method of shaping heat-shrinkable materials
WO2002048253A2 *Dec 13, 2001Jun 20, 2002Kimberly-Clark Worldwide, Inc.Materials having shape-memory
WO2002048253A3 *Dec 13, 2001Aug 14, 2003Kimberly Clark CoMaterials having shape-memory
WO2002053344A2 *Dec 21, 2001Jul 11, 2002Kimberly-Clark Worldwide, Inc.Materials having controlled shrinkage and patterns and methods of making same
WO2002053344A3 *Dec 21, 2001Jan 3, 2003Kimberly Clark CoMaterials having controlled shrinkage and patterns and methods of making same
WO2008113478A1 *Mar 5, 2008Sep 25, 2008Ludger FuestMethod for producing a tubular bag, tubular bag and film suited for producing the tubular bag
CN100430002CJun 15, 2001Nov 5, 2008Ci4B有限公司Method of shaping heat-shrinkable materials
DE102012021916A1 *Nov 9, 2012May 15, 2014Krones AgSchrumpfverpackung, Vorrichtung zur Herstellung einer Schrumpfverpackung und Verfahren zur Herstellung einer Schrumpfverpackung
EP1970310A1Mar 16, 2007Sep 17, 2008Ludger FuestMethod for manufacturing a tubular bag, tubular bag and film suitable for manufacturing the tubular bag
US6887916Dec 28, 2000May 3, 2005Kimberly-Clark Worldwide, Inc.Materials having controlled shrinkage and patterns and methods of making same
US7074484Dec 15, 2000Jul 11, 2006Kimberly-Clark Worldwide, Inc.Materials having shape-memory
US7964255Oct 4, 2007Jun 21, 2011Micro Shaping, Ltd.Heat-shrinkable multilayer material
Classifications
International ClassificationB65B53/02, B29C65/34, B65D75/00, B29C65/68, B29C61/06
Cooperative ClassificationB29C61/0625, B65D75/002, B29C65/68, B29C65/3432, B65B53/02, B29K2995/0049, B29C66/1122, B29C65/346, B29C66/347, B29C65/3452, B29C66/4322, B29C66/43121, B29C66/91653, B29C66/91655
European ClassificationB29C65/34, B29C65/68, B29C66/5221, B29C66/1122, B65D75/00B, B65B53/02, B29C61/06B3
Legal Events
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May 9, 1996AKDesignated states
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