Method for and devices used in covering a roll core with a resin infused fiber reinforced adhesive under layer and a polymeric top layer, the method including the use of an improved mold tape

• US 6,514,369 B1
• Filed: 11/28/2000
• Issued: 02/04/2003
• Est. Priority Date: 07/28/1999
• Status: Expired due to Fees

• Current Assignee: Robert H. Neese Trust
• Original Assignee: Advanced Materials Corporation
• Inventors: Shieh, Yang T.
• Primary Examiner(s): AFTERGUT, JEFFRY H
• Application Number:
  US09/723,701
• Time in Patent Office: 798 Days
• Field of Search: 156/185, 156/172, 156/171, 156/187, 156/188, 156/190, 156/191, 156/192, 156/195, 156/244.12, 156/244.13, 156/425, 156/429, 156/430, 156/154, 156/153, 492/50, 492/52
• US Class Current: 156/154
• CPC Class Codes: D21G 1/0233 Soft rolls
• CPC Class Codes: D21G 1/0246 Hard rolls
• CPC Class Codes: F16C 13/00 Rolls, drums, discs, or the like guide rollers in feeding webs B65H27/00; calender rolls, bearings therefor D21G1/02; rotary drums or rollers for heat-exchange or heat-transfer apparatus F28F5/02; Bearings or mountings therefor
• CPC Class Codes: Y10T 29/49551 Work contacting surface wound about core

Abstract

The invention includes a method for producing a covered roll having a reinforcement fiber mat under layer infused with low viscosity thermoset resin and a smooth high temperature, high performance polymeric outer layer. The mat is formed of a plurality of layers, each layer having a leading edge that abuts a following edge when wrapped over the roll core, each subsequent layer being affixed to the previous layer along a seam, the seams being spaced apart angularly from one another to prevent irregularities over the surface of the resulting roll core. One or more layers of the dry reinforcement fiber mat may be formed of a two-ply construction, the first ply having fibers arranged in a random pattern, the second ply having aligned fibers oriented either parallel or perpendicular to the roll core central axis. The invention also includes an improved mold tape assembly for use in applying a polymeric cover over a roll core and an inventive apparatus for fabricating the mold tape assembly. The mold tape assembly is formed of at least two ribbons that are arranged in a substantially parallel and partially overlapping orientation, the ribbons being spot welded together at a predetermined radius of curvature. The apparatus for fabricating the mold tape assembly further includes an inventive device for aligning the ribbons prior to welding and an inventive curvature shoe for disposing the ribbons at a predetermined radius of curvature during welding.

Claims

1. A method for producing a covered roll having a smooth polymeric outer layer and a reinforcement fiber mat under layer, said method comprising the steps of:

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

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

placing the roll core in a substantially vertical orientation such that the roll core has a top end and a bottom end;

helically winding a length of mold tape from the roll core bottom end to the top end thereof in a spaced-apart relationship with the dry reinforcement fiber mat to define an application zone between the inside surface of the mold tape and the outside surface of the dry reinforcement fiber mat;

extruding a filament of polymeric material within the application zone and helically winding the filament onto the dry reinforcement fiber mat from the roll core bottom end to the top end thereof,

allowing the wound polymeric material to cool slowly to form a continuous polymeric layer;

infusing a filler material into the dry reinforcement fiber mat layer; and

,

removing the mold tape.

2. The method of claim 1 wherein prior to said step of helically winding the mold tape, said method further includes the step of locating a spacer assembly proximate the bottom end of the roll core, the spacer assembly having a circumference greater than that of the roll core outer surface and securing a leading edge of the mold tape to the spacer assembly.

3. The method,of claim 1 wherein prior to the step of infusing a filler material, said method comprises the additional step of drilling entrance holes into the roll proximate the bottom end thereof which extend through the mold tape, the hardened polymeric layer and into the dry reinforcement fiber mat layer;

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

,

and wherein said step of infusing a filler material further includes the step of feeding a thermoset resin through those entrance holes and into the dry reinforcement fiber mat layer.

4. The method of claim 3 wherein following the step of drilling entrance holes into the roll, said method comprises the additional step of drilling at least one vacuum hole into the roll proximate the top end thereof which extends through the mold tape, the hardened polymeric layer and into the dry reinforcement fiber mat layer.

5. The method of claim 4 wherein said step of drilling further includes the step of inserting valves into the entrance holes and the at least one vacuum hole and connecting a vacuum source to the at least one vacuum hole.

6. The method of claim 2 wherein prior to said step of attaching a spacer assembly proximate the bottom end of the roll core, said method comprises the additional step of locating an extension segment on the bottom and top ends of the roll core, each extension segment comprising an outer circumference substantially the same as the outer circumference of the roll core, wherein said step of attaching a spacer assembly proximate the bottom end of the roll core further comprises the step of slidably mounting the spacer assembly over the extension segment located at the bottom end of the roll core.

7. The method of claim 6 wherein said step of helically winding the mold tape over the length of the roll core further includes the step of helically winding the mold tape over the extension segments and spacer assembly located at the ends of the roll core and wherein said step of helically winding the filament over the dry reinforcement fiber mat layer further includes the step of helically winding the filament over the outer surface of the extension segment located at the ends of the roll core such that the dry reinforcement fiber mat layer and extension segments are covered with the polymeric material.

8. The method of claim 6 wherein following the step of locating extension segments on the ends of the roll core, said method comprises the additional step of shot blasting the entire roll core outer surface and extension segments located thereon.

9. The method of claim 8 wherein following the step of shot blasting, said method comprises the additional step of brushing on a chemical solution.

10. The method of claim 1 wherein said step of helically winding the filament further includes the steps of preventing rotational movement of the roll core and causing an extruder to travel in a circular path around the non-rotatable roll core while linearly moving the roll core downwardly from an elevated start position to a lowered finish position thus winding the filament from the bottom end of the roll core to the top end thereof.

11. The method of claim 1 wherein said step of helically winding the mold tape further includes the steps of providing a spool of mold tape and preventing rotational movement of the roll core and causing the mold tape spool to travel in a circular path around the non-rotatable roll core while linearly moving the roll core downwardly from an elevated start position to a lowered finish position thus unwinding the mold tape from the spool and helically winding the mold tape over the roll core to form the application zone.

12. The method of claim 6 wherein prior to the step of locating an extension segment on each end of the roll core, said method comprises the additional step of removing all greases and oils present on the roll core outer surface by utilizing organic solvents and solutions.

13. The method of claim 2 wherein said step of feeding thermoset resin through the entrance holes further includes the step of activating the vacuum source and allowing the thermoset resin to flow into the dry reinforcement fiber mat layer until it seeps out the at least one vacuum hole and thereafter deactivating the vacuum source.

14. The method of claim 13 wherein following said step of deactivating the vacuum source, said method comprises the step of sealing all entrance holes and the at least one vacuum hole and allowing the thermoset resin to cure.

15. The method of claim 14 herein the step of allowing the epoxy resin to cure further includes the step of placing the covered roll core in an oven and rotating the covered roll core until the resin cures.

16. The method of claim 15 wherein following the step of rotating the covered roll core during resin curing, said method additionally comprises the step of machining the outside surface of the covered roll core to a predetermined diameter and smoothness.

17. The method of claim 16 wherein following the step of machining the outside surface of the covered roll core, said method comprises the additional step of severing the coated roll core at its ends to remove the extension segments and spacer assembly therefrom.