Method for control of post molding fabric curl and distortion

• US 5,756,026 A
• Filed: 01/05/1996
• Issued: 05/26/1998
• Est. Priority Date: 01/05/1996
• Status: Expired due to Fees

• Current Assignee: Fiberco Incorporated
• Original Assignee: Fiberco Incorporated
• Inventors: Sanchez, William L., Freeman, Walter J.
• Primary Examiner(s): Silbaugh, Jan H.
• Assistant Examiner(s): GRAY, ROBIN SCOTT
• Application Number:
  US08/583,513
• Time in Patent Office: 872 Days
• Field of Search: 264/243, 264/235, 264/346, 264/234, 264/345, 264/348, 264/327, 264/322, 264/324, 264/138
• US Class Current: 264/138
• CPC Class Codes: B29C 35/16 Cooling cooling extruded material B29C48/911; cooling preforms for blow moulding B29C49/6427; cooling blown articles B29C49/66; cooling tyres during post cure inflation B29D30/0643
• CPC Class Codes: B29C 37/005 Compensating volume or shape change during moulding, in general

Abstract

A process for eliminating post-molding fabric curl and distortion in molded fabrics and fabrics produced thereby. The molded fabrics are laminates including a non-woven fabric face and a binder layer and/or sheet backing. Post-molding curling and distortion can be eliminated by maintaining heat on the face fabric until the backing has been cooled enough to be rigid.

Claims

1. A process for molding textile fabrics and substantially preventing post molding fabric curl and distortion comprising:

compression molding a fabric comprising a face fabric and a backing layer in a compression mold with at least the backing layer at an elevated temperature greater than a melting temperature of the backing layer;

cooling the backing layer while the face fabric and the backing layer remain in the compression mold, at least until solidification of the backing layer; and

heating the face fabric, while cooling the backing layer, to relax stresses introduced during the compression molding.

2. The process of claim 1, wherein the compression molding comprises:

preheating the backing layer to a temperature that is greater than or equal to a melting temperature of the backing layer, but less than a melting temperature of the face fabric;

positioning the fabric over a female portion of the compression mold; and

mating a male portion of the compression mold with the female portion, thereby compressing the fabric between the male portion and the female portion.

3. The process of claim 1, further comprising:

removing the fabric from the compression mold upon the solidification of the backing layer.

4. The process of claim 3, further comprising:

placing the fabric in a tray having a shape and dimensions which are substantially the same as the compression mold; and

trimming the fabric to desired specifications.

5. The process of claim 1, wherein the compression mold comprises a mold surface which contacts the backing layer during the molding and is a cold mold having a temperature of room temperature or less than the room temperature.

6. The process of claim 1, wherein the heating of the face fabric comprises heating the face fabric to a temperature between about 60°

C. and 130°

C., and maintaining the temperature of the face fabric at least until the solidification of the backing layer.

7. The process of claim 6, wherein the heating of the face fabric comprises heating the face fabric to a temperature between about 80°

C. and 120°

C., and maintaining the temperature of the face fabric at least until the solidification of the backing layer.

8. The process of claim 7, wherein the heating of the face fabric comprises heating the face fabric to a temperature between about 90°

C. and 100°

C., and maintaining the temperature of the face fabric at least until the solidification of the backing layer.

9. The process of claim 1, wherein the heating of the face fabric comprises heating the face fabric to a temperature and maintaining the temperature of the face fabric for about 20 to 180 seconds.

10. The process of claim 9, wherein the heating of the face fabric comprises heating the face fabric to a temperature and maintaining the temperature of the face fabric for about 60 to 120 seconds.

11. The process of claim 10, wherein the heating of the face fabric comprises heating the face fabric to a temperature and maintaining the temperature of the face fabric for about 60 to 90 seconds.

12. The process of claim 1, wherein the cooling of the backing layer while the face fabric and the backing layer remain in the compression mold, at least until the solidification of the backing layer, comprises cooling the backing layer to a temperature within the range of about 35°

C. to 50°

C.

13. The process of claim 1, wherein the face fabric is selected from the group consisting of non-woven fabrics, tufted fabrics, knit fabrics and woven fabrics;

and

wherein the backing layer is selected from the group consisting of moldable latexes, moldable polyurethanes, polyethylene, polypropylene copolymers, thermoplastics having a lower melting point than polypropylene, a latex binder backed with polyethylene, a latex binder backed with at least one moldable polyurethane, a latex binder backed with at least one polypropylene copolymer, and a latex binder backed with at least one thermoplastic having a lower melting point than polypropylene.

14. The process of claim 13, wherein materials used for the face fabric comprise polyolefins.

15. The process of claim 14, wherein the polyolefins are selected from the group consisting of isotactic polypropylenes, mixtures of propylenes with polyethylenes, and resins having a melting point in the range of about 120°

C. and 130°

C. combined with propylene copolymers.

16. The process of claim 1, further comprising:

removing the fabric from the compression mold upon the solidification of the backing layer; and

heating the face fabric to supplement relaxation of stresses introduced by the molding.

26. The process of claim 16, comprising the cooling of the backing layer of the fabric, simultaneously with the heating of the face fabric, to maintain the backing layer in a substantially solid state.

27. The process of claim 16, further comprising:

placing the fabric in a tray having a shape and dimensions which are substantially the same as the compression mold, during the heating of the face fabric to supplement relaxation of stresses introduced by the molding.

28. The process of claim 26, further comprising:

placing the fabric in a tray having a shape and dimensions which are substantially the same as the compression mold, during the heating of the face fabric to supplement relaxation of stresses introduced by the molding.

17. A process for molding textile fabrics and substantially preventing post molding fabric curl and distortion comprising:

compression molding a fabric comprising a face fabric and a backing layer in a compression mold with at least the backing layer at an elevated temperature greater than a melting temperature of the backing layer;

cooling the fabric while the fabric remains in the compression mold, at least until substantial solidification of the backing layer;

removing the fabric from the compression mold upon the substantial solidification of the backing layer;

placing the fabric in a tray having a shape and dimensions which are substantially the same as the compression mold;

heating the face fabric to relax stresses introduced by the molding; and

cooling the backing layer, simultaneously with the heating of the face fabric, to maintain the substantial solidification of the backing layer.

18. The process of claim 17, further comprising:

trimming the fabric.

19. The process of claim 17, wherein the compression molding comprises:

preheating the backing layer to a temperature that is greater than or equal to a melting temperature of the backing layer, but less than a melting temperature of the face fabric;

positioning the fabric over a female portion of the compression mold; and

mating a male portion of the compression mold with the female portion, thereby compressing the fabric.

20. The process of claim 17, wherein the heating of the face fabric comprises heating the face fabric to a temperature between about 60°

C. and 130°

C.; and

wherein the cooling the of backing layer comprises maintaining the backing layer at a temperature below about 60°

C. during the heating of the face fabric.

21. The process of claim 20, wherein the heating of the face fabric comprises heating the face fabric to a temperature between about 80°

C. and 120°

C.

22. The process of claim 21, wherein the heating of the face fabric comprises heating the face fabric to a temperature between about 90°

C. and 100°

C.

23. The process of claim 17, wherein the heating of the face fabric and the cooling of the backing layer are conducted for a time period in the range of about 20 to 180 seconds.

24. The process of claim 23, wherein the heating of the face fabric and the cooling of the backing layer are conducted for a time period in the range of about 60 to 120 seconds.

25. The process of claim 24, wherein the heating of the face fabric and the cooling of the backing layer are conducted for a time period in the range of about 60 to 90 seconds.