Reformable resin fibers
The present invention contemplates a method for forming a reformable epoxy resin material into a fiber format and: (i) weaving the reformable epoxy resin material ( 10 ) with a reinforcing fiber ( 12 ) to form a woven material; (ii) stitching a secondary material ( 14 ) with reformable epoxy resin material; and optionally (iii) forming a web or mesh with the reformable epoxy resin material.
1. A method comprising:
i. forming a reformable epoxy resin material in pellet form into a weavable yarn free of any phenoxy-containing material, wherein the reformable epoxy resin includes a difunctional epoxy resin component and an amine component;
ii. stitching a multiaxial fabric with the weavable yarn, wherein the multiaxial fabric is made from an epoxy resin material that is similar to the epoxy resin material that forms the weavable yarn; and
iii. forming a laminate with the multiaxial fabric, wherein the weavable yarn blends into the multiaxial fabric upon heating so that the laminate is free of visible weavable yarn strands showing through a surface of the multiaxial fabric.
2. The method according to claim 1 , including a reinforcing fiber in the multiaxial fabric, the reinforcing fiber selected from the group consisting of glass fibers, carbon fibers, and combinations thereof.
3. The method according to claim 1 , including forming the reformable epoxy resin material into a multi-filament yarn.
4. The method according to claim 1 , wherein the reformable epoxy resin material falls below its glass transition temperature upon exposure to ambient temperature.
5. The method according to claim 2 , wherein one or more of the denier or diameter of the weavable reformable epoxy resin is substantially similar to that of the reinforcing fiber.
6. The method according to claim 1 , wherein the reformable epoxy resin material falls below its glass transition temperature prior to forming the laminate.
7. The method according to claim 1 , wherein the laminate is substantially free of any polyester yarn.
8. The method according to claim 1 , wherein the method is substantially free of surface treatment for forming class A surfaces.
9. The method according to claim 1 , wherein the method is substantially free of any surface treatment after a sanding step or cutting step.
10. The method of claim 1 , wherein the laminate includes an epoxy material layer separate from the reformable epoxy resin yarn.
11. The method according to claim 1 , wherein the ratio of the difunctional epoxy resin and the primary amine is modified to reduce the viscosity of the reformable epoxy resin material during the forming of the reformable epoxy resin into the weavable format or yarn.
12. The method according to claim 1 , wherein the reformable epoxy resin material is made with bisphenol A diglycidyl ether (BADGE) and monoethanolamine.
13. The method according to claim 1 , wherein the heating is done at a temperature of at least 150° C.
14. The method according to claim 1 , wherein the blending of the weavable yarn into the multiaxial fabric results in an increase in toughness of the laminate when compared to a stitching the multiaxial fabric with a typical thermoplastic fiber.
15. The method according to claim 1 , wherein the reformable epoxy resin adheres to the multiaxial fabric and returns to a solid state within about 10 seconds to about 60 seconds after the heating is stopped.