Claims
- 1. A pouch for absorbing liquid comprising:
- an outer liquid-permeable, flexible sheet material surrounding a volume of liquid-swellable, liquid-absorbent material, said liquid-absorbing material contained within said outer sheet material in an amount sufficient such that upon absorption of liquid, said liquid-absorbing material swells to a volume that is greater than an inner volume of said pouch, defined by seals along at least three edges of said outer sheet material;
- said outer sheet material including at least one paper sheet material layer having a wet tensile strength below about 40 grams per 25 mm in the cross-machine direction and a dry tensile strength of at least about 200 grams in the cross-machine direction, said sheet material sealed along at least said three edges to define said inner pouch volume to contain said liquid-absorbent material therein; and
- said paper sheet material layer wet strength being such that the swollen liquid-absorbent material will tear the paper sheet material layer to permit the liquid-absorbent material to expand beyond the periphery of the pouch upon absorption of liquid by said liquid-absorbent material.
- 2. The pouch of claim 1, wherein upon absorption of liquid, said paper sheet material layer ruptures proximate to a sealed edge.
- 3. The pouch of claim 1, wherein a layer of the outside sheet material includes fibers of resilient thermoplastic, essentially non-absorbing material and fluid-absorbing fibrous material.
- 4. The pouch of claim 1, wherein said liquid-absorbent material comprises a liquid-absorbing polymer.
- 5. The pouch of claim 1, wherein said outer sheet material is formed into a pouch by heat sealing adjacent edges of the same, folded over sheet material layers, or by heat sealing two separate sheet material layers adjacent peripheral edges thereof.
- 6. The pouch of claim 5, wherein said adjacent peripheral edges of said sheet material are secured together with a strip of adhesive material applied between said adjacent peripheral edges.
- 7. The pouch of claim 1, wherein said intermediate layer comprises a liquid-absorbing polymer in powder from intermixed with fibrous cellulose material.
- 8. The pouch of claim 1, wherein said liquid-absorbing polymer comprises a water-absorbent, cross-linked polacrylate.
- 9. The pouch of claim 1, wherein said liquid-absorbing polymer comprises a cross-linked neutralized polyacrylic acid resin.
- 10. The pouch of claim 1 comprising an inner layer of liquid swellable, liquid-absorbing polymer material sandwiched between (a) a fabric sheet containing both thermoplastic and water-absorbent fibers and (b) a paper sheet having a wet tensile strength in the cross-machine direction below about 25 grams and a dry tensile strength in the cross-machine direction above about 200 grams; said two sheets sealed together along at least three peripheral edges.
- 11. The pouch of claim 1, wherein:
- said sheet material surrounding said liquid-absorbent materials is folded over along a mid-portion thereof leaving three peripheral edges extending from a fold line; and
- said three peripheral edges of said folded sheet material sheet sealed to itself surrounding said liquid-absorbent material to form said pouch.
- 12. The pouch of claim 11, wherein said outer sheet material is substantially rectangular in shape and said fold line bisects said rectangular shape.
- 13. The pouch of claim 12, wherein the two sheets are secured together with lines of non-liquid-absorbing adhesive material along said peripheral edges.
- 14. The pouch of claim 12, wherein the two sheets are secured together with lines of non-liquid-absorbing adhesive material along said peripheral edges.
- 15. The pouch of claim 10, wherein a layer of the outer sheet material comprises a two-phase, lightweight, air-permeable, heat seal fabric of blended thermoplastic fibers, and cellulose fibers.
- 16. The pouch of claim 15, wherein the outer fabric layer of sheet material has a wet tensile strength when completely wetted with water in a range of abut 200-600 grams per 25 mm.
- 17. The pouch of claim 1 disposed in contact with a foodstuff and the like materials that release liquid therefrom.
- 18. The pouch of claim 20, wherein a weaker sealed edge is formed by heat sealing said weaker seal using a different temperature, pressure and/or time than other heat sealed edges such that said weaker heat seal will delaminate before the outer sheet material ruptures to allow escape of said liquid-absorbent material through said delaminated heat seal.
- 19. The pouch of claim 18, wherein said weaker heat seal is formed by heat sealing two adjacent edges of said outer sheet material at a temperature in the range of about 105.degree. C. to about 120.degree. C. and wherein the stronger heat seals are formed at a temperature of about 110.degree. C. to about 125.degree. C., said weaker heat seals formed at a temperature of about 3.degree. C. to about 12.degree. C. below the stronger heat seals.
- 20. A pouch for absorbing liquid comprising:
- an outer liquid-permeable, flexible sheet material surrounding a volume of liquid-swellable, liquid-absorbent material, said liquid-absorbing material contained within said outer sheet material in an amount sufficient such that upon absorption of liquid, said liquid-absorbing material swells to a volume that is greater than an inner volume of said pouch, defined by seals along at least three edges of said outer sheet material;
- said outer sheet material sealed along at least said three edges to define said inner pouch volume to contain said liquid-absorbent material therein; and
- said sheet material having sufficient wet strength, in relation to a force required to separate at least one of said sealed pouch edges, such that the swollen liquid-absorbent material will expand beyond the periphery of the pouch upon absorption of liquid by said liquid-absorbent material by delamination of one of the sealed edges.
- 21. The pouch of claim 20, wherein the outside sheet material includes a fabric layer containing fibers of resilient thermoplastic, essentially non-absorbing material and fluid-absorbing fibrous material.
- 22. The pouch of claim 20, wherein said liquid-absorbent material comprises a liquid-absorbing polymer.
- 23. The pouch of claim 20, wherein said outer sheet material is formed into a pouch by heat sealing adjacent edges of the same, folded over sheet material layers, or by heat sealing two separate sheet material layers adjacent peripheral edges thereof.
- 24. The pouch of claim 23, wherein said adjacent peripheral edges of said sheet material are secured together with a strip of adhesive material applied between said adjacent peripheral edges.
- 25. The pouch of claim 20, wherein said liquid-absorbent material comprises a liquid-absorbing polymer in powder form intermixed with fibrous cellulose material.
- 26. The pouch of claim 20, wherein said liquid-absorbing polymer comprises a water-absorbent, cross-linked polyacrylate.
- 27. The pouch of claim 20, wherein said liquid-absorbing polymer comprises a cross-linked neutralized polyacrylic acid resin.
- 28. The pouch of claim 20, wherein:
- said sheet material surrounding said liquid-absorbent material is folded over along a mid-portion thereof leaving three peripheral edges extending from a fold line; and
- said three peripheral edges of said folded sheet material sheet is sealed to itself surrounding said liquid-absorbent material to form said pouch.
- 29. The pouch of claim 28, wherein said outer sheet material is substantially rectangular in shape and said fold line bisects said rectangular shape.
- 30. The pouch of claim 29, wherein the two sheets are secured together with lines of non-liquid-absorbing adhesive material along said peripheral edges.
- 31. The pouch of claim 29, wherein the two sheets are secured together with lines of non-liquid-absorbing adhesive material along said peripheral edges.
- 32. The pouch of claim 20, wherein the outer sheet material comprises a two-phase, lightweight, air-permeable, heat seal fabric layer containing a blend of thermoplastic fibers and cellulose fibers.
- 33. The pouch of claim 32, wherein the outer sheet material fabric layer has a wet tensile strength when completely wetted with water in a range of about 200-600 grams per 25 mm.
- 34. The pouch of claim 20, disposed in contact with a foodstuff or the like material that releases liquid therefrom.
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of copending application Ser. No. 07/858,206 filed Mar. 26, 1992 now abandoned which is a continuation-in-part of application Ser. No. 07/785,889 filed Oct. 30, 1991, now abandoned, which is a continuation of application Ser. No. 07/343,812 filed Apr. 24, 1989, now abandoned.
US Referenced Citations (7)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0395223A2 |
Oct 1990 |
EPX |
1800221 |
Apr 1970 |
DEX |
2234688A |
Feb 1991 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
343812 |
Apr 1989 |
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Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
858206 |
Mar 1992 |
|
Parent |
785889 |
Oct 1991 |
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