GB2283723A

GB2283723A - Laundry bag with water soluble closure strip

Info

Publication number: GB2283723A
Application number: GB9323393A
Authority: GB
Inventors: Martin Keith May
Original assignee: HPC FLEXIBLE PACKAGING Ltd
Current assignee: HPC FLEXIBLE PACKAGING Ltd
Priority date: 1993-11-12
Filing date: 1993-11-12
Publication date: 1995-05-17
Anticipated expiration: 2013-11-12
Also published as: GB9323393D0; GB2283723B

Abstract

A bag 10 for receiving contaminated laundry includes a closure 25 adapted to be opened when the bag is immersed in a washing fluid, such as water, the closure comprising a release strip 18 formed from a material soluble in said fluid disposed between overlapping marginal edge portions of the bag, the release strip being bonded to each of the overlapping marginal portions by at least one band of adhesive 23, 24, the bands of adhesive on opposite sides of the release strips being spaced laterally apart so as to expose the region of the strip 18a between the bands of adhesive to said fluid when the bag is immersed in said fluid. One side of the bag 15 is left open to allow filling and is then sealed in a conventional manner. More than one band of adhesive may be used on each side (Figure 4). <IMAGE>

Description

LAUNDRY BAG The present invention relates to bags for contaminated laundry and a method of making such bags.

It is known, for example in hospitals, to provide bags for holding contaminated laundry prior to loading the bag and its contents into a washing machine. Such bags have a closure and when immersed in water the bag opens due to dissolution of the bag or the closure to thereby release the washing.

According to one aspect of the present invention there is provided a bag for receiving contaminated laundry, the bag comprising plastics sheet or film forming front and rear walls, an opening for loading laundry into the bag and a closure adapted to be opened when the bag is immersed in a washing fluid, such as water, the closure comprising overlapping marginal edge portions of the plastics sheet or film and a release strip formed from a material soluble in said fluid disposed between the overlapping marginal edge portions, the release strip being bonded to each of the overlapping marginal portions by at least one band of adhesive, the bands of adhesive on opposite sides of the release strips being spaced laterally apart so as to expose the region of the strip between the bands of adhesive to said fluid when the bag is immersed in said fluid.

According to a further aspect of the present invention there is provided a method of producing a bag as defined above, the method including forming the closure by overlapping marginal edge portions of the plastics film or sheet and locating the release strip therebetween and bonding the release strip to each overlapping marginal edge portion by at least one band of adhesive, the bands of adhesive on opposite sides of the release strip being spaced apart laterally of the strip. Preferably the adhesive is a hot melt adhesive. Each band of adhesive may be defined by a continuous strip of adhesive or by a series of discrete spaced apart regions of adhesive.

Preferably at least on one side of the release strip, a single band of adhesive is provided.

Various aspects of the present invention are herein described with reference to the accompanying drawing, in which: Figure 1 shows a diagrammatic view of one embodiment of the invention; Figure 2 is a section through II of Figure 1; Figure 3 is a section through II of Figure 1 showing an alternative of Figure 2; Figure 4 shows an alternative arrangement of the closure of the bag of Figures 1 to 3; and Figure 5 shows an apparatus for making the bag of Figures 1 to 4.

Referring to the drawings, there is shown a bag 10 for receiving contaminated laundry to be loaded into the washing machine for washing.

The bag 10 is formed of two superimposed layers of plastics material film or sheet such as polypropylene although other plastics material such as polyvinyl chloride or polyethylene may be used. The superimposed layers include a front wall 12 and a rear wall 13 preferably formed from the same film or sheet by folding about fold line 11 at one side of the bag and joining along the base by a width-wise welded seam 14. The front and rear walls 12, 13 at the top of the bag 10 not joined together form an opening 15 to the bag enabling articles of contaminated clothing to be loaded into the bag 10.

The thickness of the sheet or film of the bag 10 may vary according to the particular weight of clothing to be contained by the bag 10, for example the thickness may be preferably in the range of from 25 to 65 microns.

The bag 10 includes a closure 25 which is adapted to be opened when the bag is immersed in water to enable the contents to empty out of the bag.

The closure 25 includes a marginal edge portion 20 of the wall 13 which extends beyond the opposite side and a terminal edge 21 of the front wall 12 of the bag 10 and is folded about a fold 17 to overlie a marginal edge portion F of the front wall 12. Marginal portion 20 extends the full length of the bag 10 and is preferably folded before being joined at the base by the welded seam 14.

The closure 25 further includes a release strip 18 preferably comprising a water soluble plastics film. The strip 18 extends the full length of the bag 10, is disposed between and is preferably substantially the same width as the marginal overlapping portions F, 20 of the front and rear walls 12, 13. Preferably the water-soluble material is polyvinyl alcohol or a glycol plasticiser/polyvinyl alcohol mixture and has a thickness preferably in the range of 12 to 60 microns.

The release strip 18 is bonded to the overlapping marginal portions F, 20 by two parallel relatively narrow bands of adhesive 23, 24, preferably hot melt adhesive, which are laterally spaced apart relative to the strip 18 to define a strip portion 18a therebetween for exposure to water when the bag is immersed in a body of water for washing of the laundry.

In the embodiment shown in Figure 2 band 23 is located adjacent fold 17 and band 24 is located further away from fold 17. Figure 3 shows an alternative arrangement wherein band 24 is located adjacent fold 17 and band 23 is located further away from fold 17.

In both cases a flap 20a is defined as by adhesive band 23 creating a gap 16 for permitting ingress of water to the strip portion 18a. As water enters through the gap 16 water permeates and dissolves the strip portion 18a thereby opening the closure 25 by permitting the overlapping marginal edge portions F,20 to separate along the full length of the bag 10 about the dissolved portion 18a to release of the contents of the bag 10. The provision of portion 1 8a offers a wide surface area for exposure to water to facilitate dissolutions and the provision of a flap 20a facilitates access of water to the portion 18a.

The closure 25 in the embodiment shown in Figures 2 and 3 extends longitudinally down one side of the bag 10. However it will be appreciated that the position of the closure 25 may vary, for example, it may extend longitudinally down the middle of either front or rear walls 12, 13 or may extend in a width-wise direction of the bag 10.

It is envisaged that the number and position of the adhesive bands 23, 24 may vary provided that the bands located on one side are laterally spaced from bands on the opposite side of the release strip 18. For example as shown in Figure 4 there are two bands 23, and two bands 24 arranged in parallel to one another on opposite sides of the release strip 18. The two adhesive bands 23 are disposed between opposed faces of the front wall 12 and the release strip 18. One of the adhesive bands 23 extends along one edge of the release strip 18 adjacent the fold 17 and the other band 23 extends adjacent an opposite edge of the release strip 18 adjacent terminal edge 22 of the rear wall 13. The two bands of adhesive 24 on the opposite side of the release strip 18 are inboard of adhesive bands 23 to define with bands 23 two strip portions 18a, 18b. On immersion, water initially dissolves away portion 18a and then has access to portion 18b. Once portion 18b is dissolved, the closure 25 is opened.

In the embodiments described above, the release strip 18 is referred to as being water soluble. However, it will be appreciated that if washing fluids other than water are to be used, then the strip 18 would comprise a material which is soluble in that washing fluid.

In use, contaminated clothing is loaded into the bag 10 through opening 15 which is then sealed in a conventional manner. The bag plus its contents are then transported to a point at which the contaminated clothes are to be washed. The bag 10 plus the contents are then subsequently loaded into a washing machine and the wash cycle initiated. During the initial stages of the wash cycle, water in the washing machine causes the release strip 18 to dissolve, the closure 25 consequently opens to allow the contents of the bag to escape from the bag 10 into the water for washing.

The construction of the bags 10 enables them to be easily produced on a continuous production line. An example of a method of production is schematically illustrated in Figure 5 which shows an apparatus 60 for forming the laundry bags of the present invention. The apparatus 60 shown comprises a feed end 61, for feeding a tubular web 40 of plastics material, and a discharge end 62, from which the formed bags 10 are discharged.

Between the feed end 61 and the discharge end 62 and moving downstream from the feed end 61 is a primary drive means (not shown), cutting station 41, unfolding station 42, first adhesive applicator 44, film applicator 46, second adhesive applicator, folding station 47, severing/sealing station 50, and secondary drive means (not shown).

Primary and secondary drive means (not shown) comprise a plurality of rollers respectively which continuously feed the tubular web 40 to make the bags 10 and maintain the web 40 at the correct tension during the processing of the bags 10.

As the web 40 enters, being drawn along between the primary and secondary drives (not shown), the cutting station 41 produces a longitudinal slit 43 which opens a wall of the web 40 in a length-wise direction. The web 40 is then drawn past the unfolding station 42 which opens up a marginal portion 20 of the rear wall 13. First adhesive applicator 44 is operated to continuously apply a first adhesive band 24 onto a front wall 12 of the open web 40. A release strip applicator 46 continuously operates to apply the release strip 18 so as to cover and be adhered by the first adhesive band 24. A second adhesive applicator 45 continuously applies a second adhesive band 23 onto the release strip 18 in a length-wise direction of the web 40 adjacent an edge 21 of the front wall 12 of the opened slit 43.

Folding station 47 operates to fold the marginal portion 20 of the rear wall 13 to overlie a marginal portion of the front wall 12 and be bonded to marginal portion F by adhesive band 23. Preferably the adhesive bands 23, 24 comprise hot melt adhesive. A suitable hot melt adhesive may comprise a thermoplastic synthetic rubber, hydrogenated hydrocarbon resin, stabiliser resin est, and anti-oxidant mixture. Finally the web 40 is fed to a severing/sealing station 50 in which the web 40 is severed by cutting member 48 and sealed by heat sealing member 49 to form the bags 10. In this manner as the bags 10 are severed the cutting member 48 forms an access opening 15 for next bag 10 to be severed. Preferably a press roller (not shown) may be situated between folding station 47 and severing/sealing station 50 operable to press the adhered surfaces of the bag 10 to be formed and the water-soluble film 18 firmly together to ensure good adhesion of the opposed surfaces.

Claims

1. A bag for receiving contaminated laundry, the bag comprising plastics sheet or film forming front and rear walls, an opening for loading laundry into the bag and a closure adapted to be opened when the bag is immersed in a washing fluid, such as water, the closure comprising overlapping marginal edge portions of the plastics sheet or film and a release strip formed from a material soluble in said fluid disposed between the overlapping marginal edge portions, the release strip being bonded to each of the overlapping marginal portions by at least one band of adhesive, the bands of adhesive on opposite sides of the release strips being spaced laterally apart so as to expose the region of the strip between the bands of adhesive to said fluid when the bag is immersed in said fluid.

2. A bag according to claim 1 wherein the adhesive is a hot melt adhesive.

3. A bag according to claim 1 or 2 wherein each band of adhesive is defined by a continuous strip of adhesive.

4. A bag according to claim 1 or 2 wherein each band of adhesive is defined by a series of discrete spaced apart regions of adhesive.

5. A bag according to any preceding claim wherein at least on one side of the release strip, a single band of adhesive is provided.

6. A bag according to any preceding claim wherein the release strip is a water soluble plastics film.

7. A bag according to claim 6 wherein the film has a thickness of 12 to 60 microns.

8. A bag for receiving laundry substantially as herein described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

9. A method producing a bag according to claim 1, the method including forming the closure by overlapping marginal edge portions of the plastics film or sheet and locating the release strip therebetween and bonding the release strip to each overlapping marginal edge portion by at least one band of adhesive, the bands of adhesive on opposite sides of the release strip being spaced apart laterally of the strip.

10. A method of producing a bag according to claim 1 substantially as herein described with reference to the accompanying drawings.