Surface treatment for blanket of thermoplastic fibers

• US 20040265553A1
• Filed: 06/30/2003
• Published: 12/30/2004
• Est. Priority Date: 06/30/2003
• Status: Active Grant

• Current Assignee: Owens Corning Intellectual Capital, LLC (Owens Corning)
• Original Assignee: Owens- Corning Fiberglas Technology Incorporated (Owens Corning)
• Inventors: Tilton, Jeffrey A., Rockwell, Anthoney L.
• Granted Patent: US 7,128,561 B2
• Time in Patent Office: Days
• US Class Current: 428/218
• CPC Class Codes: B29C 2043/483 cooperating with a second endless belt, i.e. double band presses
• CPC Class Codes: B29C 43/228 using endless belts feeding the material between non-rotating pressure members, e.g. vibrating pressure members
• CPC Class Codes: D04H 13/00 Other non-woven fabrics
• CPC Class Codes: E04B 1/7662 comprising fiber blankets or batts
• CPC Class Codes: Y10T 428/24942 including components having same physical characteristic in differing degree
• CPC Class Codes: Y10T 428/2495 Thickness [relative or absolute]
• CPC Class Codes: Y10T 428/24992 Density or compression of components
• CPC Class Codes: Y10T 428/249933 Fiber embedded in or on the surface of a natural or synthetic rubber matrix

Abstract

An apparatus and method are provided for forming a densified surface layer on a thermoplastic blanket. The apparatus includes first and second continuous belts, a treatment zone defined between those belts, first and second heating and densifying units and a cooler downstream from the heating and densifying units. The method includes the steps of continuously forming a densified surface layer on a face of a thermoplastic blanket and making the thermoplastic blanket with the densified surface layer to a desired thickness within strict dimensional tolerances. A densified thermoplastic blanket product is also disclosed.

Claims

1. an apparatus for forming a densified surface layer on a thermoplastic blanket, comprising:

a first continuous belt;

a second continuous belt;

a treatment zone defined between said first and second belts;

a first heating and densifying unit;

a second heating and densifying unit downstream from said first heating and densifying unit; and

a cooler downstream from said second heating and densifying unit.

2. The apparatus of claim 1 further including a thermoplastic blanket feeder upstream from said first and second continuous belts.

3. The apparatus of claim 1, further including a first facing feeder for feeding facing into said treatment zone between said thermoplastic blanket and said first belt.

4. The apparatus of claim 1, further including a second facing feeder for feeding a facing into said treatment zone between said thermoplastic blanket and said second belt.

5. The apparatus of claim 2, further including a first facing feeder for feeding a facing into said treatment zone between said thermoplastic blanket and said first belt and a second facing feeder for feeding a facing into said treatment zone between said thermoplastic blanket and said second belt.

6. The apparatus of claim 1, wherein said first heating and densifying unit includes a first platen, a second platen, means for heating said first platen, means for heating said second platen and means for displacing said first platen.

7. The apparatus of claim 1, wherein said second heating and densifying unit includes a third platen, a fourth platen, means for heating said third platen, means for heating said fourth platen and means for displacing said third platen.

8. The apparatus of claim 1, wherein said cooler includes a fan.

9. The apparatus of claim 1, wherein said first belt is constructed from polytetrafluoroethylene.

10. The apparatus of claim 1, wherein said first belt is constructed from closed weave polytetrafluoroethylene.

11. The apparatus of claim 1, wherein said second belt is constructed from polytetrafluoroethylene.

12. The apparatus of claim 1 wherein said second belt is constructed from closed weave polytetrafluoroethylene.

13. The apparatus of claim 10 wherein said first belt is a continuous belt with an overlap splice.

14. The apparatus of claim 12, wherein said second belt is a continuous belt with an overlap splice.

15. The apparatus of claim 6, wherein said platens are constructed from aluminum.

16. The apparatus of claim 7, wherein said platens are constructed from aluminum.

17. The apparatus of claim 6, wherein said means for heating said first platen includes a first electric variable heating circuit.

18. The apparatus of claim 17, wherein said first electric variable heating circuit includes watt densities in graduated steps of about 13.7 watts per inch in the first nine inches of platen, and 11.85 watts in the next twenty inches of platen, with 5.5 watts per square inch over the remainder of the platen.

19. The apparatus of claim 7, wherein said means for heating said third platen includes a second variable electric heating circuit.

20. The apparatus of claim 19, wherein said second variable electric heating circuit includes watt densities in graduated steps of about 13.7 watts per inch in the first nine inches of platen, and 11.85 watts in the next twenty inches of platen, with 5.5 watts per square inch over the remainder of the platen.

21. A method of processing a thermoplastic blanket, comprising:

continuously and simultaneously forming a densified surface layer on each of two opposing faces of a thermoplastic blanket having a density D prior to said forming; and

maintaining a core section of said thermoplastic blanket between said opposing densified surface layers at an increase in density of no more than about 0 to about 15% of D following forming.

22. A method of processing a thermoplastic blanket, comprising:

continuously forming a densified surface layer on a face of a thermoplastic blanket; and

making said thermoplastic blanket with said densified surface layer to a desired thickness T within strict tolerances of ±

0.015 inches.

23. A method of processing a thermoplastic blanket, comprising:

continuously forming a densified surface layer on a face of a thermoplastic blanket by densifying said densified surface layer about two to about ten times from a starting density D within a time frame of between about 10-60 seconds while maintaining a section of said thermoplastic blanket at an increase in density of no more than about 10-40% of D following forming.

24. A method of processing a thermoplastic blanket, comprising:

introducing a thermoplastic blanket into a nip formed between two processing belts;

applying heat and pressure to said thermoplastic blanket through said processing belts so as to form a densified surface layer on at least one face of said thermoplastic blanket.

25. The method of claim 24 including heating said thermoplastic blanket along said face to be densified to a temperature of between about 350 degrees to about 450 degrees.

26. The method of claim 25, including compressing said thermoplastic blanket with a force of between about 0.5 pounds per square foot-10.0 pounds per square foot.

27. The method of claim 26, including applying said heat and pressure for a duration of between about 10-60 seconds.

28. The method of claim 24, including cooling said thermoplastic blanket below a softening temperature characteristic of material from which said thermoplastic blanket is constructed prior to releasing said pressure.

29. A method of processing a thermoplastic blanket, comprising:

introducing a thermoplastic blanket into a nip formed between two continuous processing belts constructed of closed weave polytetrafluoro-ethylene with an overlap splice; and

applying heat and pressure to said thermoplastic blanket through said processing belts so as to form a densified surface layer on at least one face of said thermoplastic blanket.

30. The method of claim 29 including heating said thermoplastic blanket along said face to be densified to a temperature of between about 350 degrees to about 450 degrees.

31. The method of claim 30, including compressing said thermoplastic blanket with a force of between about 0.5 pounds per square foot-10.0 pounds per square foot.

32. The method of claim 31, including applying said heat and pressure for a duration of between about 10-60 seconds.

33. The method of claim 29, including cooling said thermoplastic blanket below a softening temperature characteristic of material from which said thermoplastic blanket is constructed prior to releasing said pressure.

34. A thermoplastic blanket, comprising:

a first densified surface layer;

a second densified surface layer; and

a base layer between said first and second densified layers;

said thermoplastic blanket being characterized by said first and second densified surface layers having a density of between about 1.5 to about 30.0 pcf and said base layer having a density of between about 0.5 to about 10.0 pcf.

35. The thermoplastic blanket of claim 34 wherein said first and second densified surface layers have a thickness of between about 0.01 to about 0.1 inches and said base layer has a thickness of between about 0.25 to about 4.0 inches.

36. The thermoplastic blanket of claim 35 wherein said thermoplastic blanket is formed from a polymer based thermoplastic material.

37. The thermoplastic blanket of claim 36, wherein said polymer based thermoplastic material is selected from a group consisting of polyester, polyethylene, polypropylene, polyethylene terephthalate, rayon, nylon, and any mixtures thereof.

38. The thermoplastic blanket of claim 37, wherein said polymer based thermoplastic material includes fibers selected from a group consisting of glass fibers, natural fibers and mixtures thereof.

39. The thermoplastic blanket of claim 35, further including a facing layer on said thermoplastic blanket.

40. The thermoplastic blanket of claim 39, wherein said facing layer is selected from a group consisting of polyester, rayon, metallic foil and mixtures thereof.

41. The thermoplastic blanket of claim 35, further including a first facing layer on a first face of said thermoplastic blanket and a second facing layer on a second face of said thermoplastic blanket.

42. The thermoplastic blanket of claim 41, wherein said first and second facing layers are selected from a group consisting of polyester, rayon, metallic foil and mixtures thereof.

43. The thermoplastic blanket of claim 35 wherein said base layer is at least partially constructed from material selected from a group consisting of thermoset polymer material, fiber glass, foam, mineral fiber, cardboard and mixtures thereof.

44. A thermoplastic blanket, comprising:

a densified surface layer having a density of between about 1.5 to about 30.0 pcf and a thickness of between about 0.01 to about 0.1 inches; and

a base layer having a density of between about 0.5 to about 10.0 pcf and a thickness of between about 0.25 to about 4.0 inches.

45. The thermoplastic blanket of claim 44 wherein said thermoplastic blanket is formed from a polymer based thermoplastic material.

46. The thermoplastic blanket of claim 45, wherein said polymer based thermoplastic material is selected from a group consisting of polyester, polyethylene, polypropylene, polyethylene terephthalate, rayon, nylon, and any mixtures thereof.

47. The thermoplastic blanket of claim 46, wherein said polymer based thermoplastic material includes fibers selected from a group consisting of glass fibers, natural fibers and mixtures thereof.

48. The thermoplastic blanket of claim 44, further including a facing layer on said thermoplastic blanket.

49. The thermoplastic blanket of claim 48, wherein said facing layer is selected from a group consisting of polyester, rayon, metallic foil and mixtures thereof.

50. The thermoplastic blanket of claim 44, further including a first facing layer on a first face of said thermoplastic blanket and a second facing layer on a second face of said thermoplastic blanket.

51. The thermoplastic blanket of claim 50, wherein said first and second facing layers are selected from a group consisting of polyester, rayon, metallic foil and mixtures thereof.

52. The thermoplastic blanket of claim 44, wherein said base layer is at least partially constructed from material selected from a group consisting of thermoset polymer material, fiber glass, foam, mineral fiber, cardboard and mixtures thereof.