Method for making a cover for a roll core having a multiple layer construction and having minimal residual stresses

• US 20020189749A1
• Filed: 05/16/2002
• Published: 12/19/2002
• Est. Priority Date: 05/18/2000
• Status: Abandoned Application

• Current Assignee: Advanced Materials Corporation
• Original Assignee: Advanced Materials Corporation
• Inventors: Shieh, Yang T.
• Application Number:
  US10/147,753
• Publication Number:
  US 20020189749A1
• Time in Patent Office: Days
• US Class Current: 156/172
• CPC Class Codes: B29C 35/02 Heating or curing, e.g. crosslinking or vulcanizing during moulding, e.g. in a mouldcold vulcanisation B29C35/18 ; vulcanising tyres, presses therefor B29D30/0601
• CPC Class Codes: B29C 63/0013 Removing old coatings
• CPC Class Codes: B29C 63/10 around tubular articles
• CPC Class Codes: B29C 70/32 on a rotating mould, former or core
• CPC Class Codes: B29C 70/36 and impregnating by casting, e.g. vacuum casting
• CPC Class Codes: B29C 70/86 Incorporated in coherent impregnated reinforcing layers, e.g. by winding
• CPC Class Codes: B29K 2063/00 Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2075/00 Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/0809 Fabrics
• CPC Class Codes: B29K 2105/0854 in the form of a non-woven mat
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B29L 2031/324 Rollers or cylinders having an axial length of several times the diameter, e.g. embossing, pressing or printing
• CPC Class Codes: D21F 1/40 Rolls
• CPC Class Codes: D21F 3/08 Pressure rolls
• CPC Class Codes: D21G 1/0233 Soft rolls
• CPC Class Codes: D21G 1/0246 Hard rolls

Abstract

A method is disclosed for producing a covered roll having a multi-layered construction. A first embodiment includes a plurality of steps. The first step is to provide a cylindrical roll core having two ends, a length therebetween, and an outer surface. Next, a dry fiber mat layer is tightly wrapped over the roll core outer surface. A fabric, in the form of a strip, is impregnated with a thermoset resin such as epoxy or urethane. The roll core is then rotated and the thermoset resin impregnated fabric strip is helically wound over the tightly wrapped dry fiber mat layer. Tension is maintained while winding the thermoset resin impregnated fabric strip to form a fabric layer.

Claims

1. A method for producing a covered roll, the covered roll having a multi-layered, construction, said method comprising the steps of:

a. providing a cylindrical roll core, the roll core having two ends, a length therebetween, and an outer surface;

b. tightly wrapping a dry fiber mat over the roll core outer surface;

c. impregnating a fabric in the form of a strip with a thermoset resin;

d. helically winding said impregnated fabric strip over the tightly wrapped dry fiber mat while rotating said roll core and maintaining said fabric strip under tension to form a fabric layer;

e. curing said thermoset resin; and

,

f. infusing a filler material into the dry fiber mat layer.

2. A method as in claim 1 wherein prior to said step of tightly wrapping a dry fiber mat over a substantial portion of the roll core outer surface, said method comprises the further step of placing the roll in a substantially horizontal orientation.

3. A method as in claim 2 wherein prior to said step of infusing a filler material, said method comprises the further step of tilting the roll core to a non-horizontal orientation, the roll core oriented as such including a bottom end and a top end.

4. A method as in claim 3 wherein said step of infusing a filler material into the dry fiber mat layer includes the sub-steps of:

a. drilling entrance holes into the roll proximate the bottom end thereof which extend through the fabric layer and into the dry fiber mat layer;

b. sealing the roll at the bottom end thereof with a sealing material; and

,

c. feeding a thermoset resin through those entrance holes and into the dry fiber mat layer.

5. A method as in claim 4 wherein following said step of drilling entrance holes into the roll, said method comprises the further step of drilling at least one vacuum hole into the roll proximate the top end thereof which extends through the fabric layer and into the dry fiber mat layer.

6. A method as in claim 5 wherein said step of drilling further includes the sub-steps of:

a. inserting valves into the entrance holes and into the at least one vacuum hole; and

,

b. connecting a vacuum source to the at least one vacuum hole.

7. A method as in claim 2 wherein following said step of placing the roll in a substantially horizontal orientation, said method comprises the further step of locating an extension segment on each end of the roll core, each extension segment comprising an outer circumference substantially the same as the outer circumference of the roll core.

8. A method as in claim 7 wherein said step of tightly wrapping a dry fiber mat layer over the roll core outer surface further includes the sub-step of tightly wrapping the fiber mat layer over the extension segments located at the ends of the roll core and wherein said step of helically winding said fabric strip tightly about the outer surface of said roll core further includes the sub-step of helically winding said fabric strip tightly over the outer surface of the extension segment located at the ends of the roll core.

9. A method as in claim 7 wherein following said step of locating extension segments on the ends of the roll core, said method comprises the further step of shot blasting the entire roll core outer surface and extension segments located thereon.

10. A method as in claim 9 wherein following said step of shot blasting, said method comprises the further step of brushing on a chemical solution.

11. A method as in claim 7 wherein prior to the step of locating an extension segment on each end of the roll core, said method comprises the further step of removing all greases and oils present on the roll core outer surface by utilizing organic solvents and solutions.

12. A method as in claim 4 wherein said step of feeding a thermoset resin through the entrance holes further includes the sub-steps of:

a. activating a vacuum source and allowing the thermoset resin to flow into the dry fiber mat layer until it seeps out the at least one vacuum hole; and

,

b. thereafter deactivating the vacuum source.

13. A method as in claim 12 wherein following said step of deactivating the vacuum source, said method comprises the further steps of sealing all entrance holes, sealing the at least one vacuum hole and allowing the thermoset resin to gel for a predetermined period of time.

14. A method as in claim 13 wherein following said step of allowing the thermoset resin to gel for a predetermined period of time, said method comprises the further steps of returning the roll core to a substantially horizontal orientation, placing the roll core in an oven and curing the roll core for a predetermined period of time.

15. A method as in claim 14 wherein said step of curing further includes the sub-step of rotating the covered roll core.

16. A method as in claim 15 wherein following said curing step, said method comprises the further step of machining the outside surface of the covered roll core to a predetermined diameter and smoothness.

17. A method as in claim 16 wherein following said step of machining the outside surface of the covered roll core, said method comprises the further step of severing the coated roll core at its ends to remove the extension segments therefrom.

18. A method as set forth in claim 1, wherein prior to said step of tightly wrapping a dry fiber mat layer over the roll core outer surface, said method comprises the further step of applying an adhesive to the roll core outer surface.

19. A method as set forth in claim 1, wherein said fabric strip is formed of glass fibers.

20. A method as set forth in claim 1, wherein said fabric strip is formed of KEVLAR®

fibers.

21. A method as in claim 1 wherein said fabric strip is wound over the tightly wrapped dry fiber mat layer in such a manner that the convolutions of said fabric strip are substantially parallel to each other, extend substantially perpendicular to the longitudinal axis of said roll core, and have a longitudinal edge overlapping the adjacent longitudinal edge of the immediately preceding turn.

22. A method as in claim 1 wherein prior to said step of impregnating a fabric in the form of a strip with a thermoset resin, said method comprises the further step of helically winding the fabric strip in a dry state over the tightly wrapped dry fiber mat layer while rotating said roll core and maintaining said dry fabric strip under tension.

23. A method as in claim 22 wherein said step of helically winding the dry fabric strip includes winding for two passes over the entire length of said roll core and wherein said step of helically winding said impregnated fabric strip includes winding for two passes over the entire length of said role core.

24. A method as in claim 22 wherein said step of helically winding a dry fabric strip includes winding for one pass over the entire length of said roll core and wherein said step of helically winding said impregnated fabric strip includes winding for three passes over the entire length of said role core.

25. A method as in claim 1 wherein said fiber mat layer comprises glass fibers.

26. A method as in claim 1 wherein said fiber mat layer comprises carbon fibers.

27. A method as in claim 1 wherein said fiber mat layer comprises aramid fibers.

28. A method as in claim 1 wherein said thermoset resin is an epoxy resin.

29. A method as in claim 1 wherein said thermoset resin is urethane.

30. A method as in claim 21 wherein the convolutions of said fabric strip overlap by a degree of approximately 50%.

31. A method as in claim 21 wherein the convolutions of said fabric strip overlap by a degree of approximately 0%.

32. A method as in claim 21 wherein the convolutions of said fabric strip overlap by a degree of approximately 90%.

33. A method as in claim 21 wherein the convolutions of said fabric strip overlap by a degree of between approximately 0% and approximately 90%.

34. A method as in claim 1 wherein the covered roll is in tended to be exposed to a predetermined operational temperature when placed into service and wherein said step of curing said thermoset resin is done at a temperature higher than said predetermined operational temperature.

35. The method as in claim 34 wherein said step of curing is done at a temperature approximately 30°

F. higher than said predetermined operational temperature.