System for producing a fully impregnated thermoplastic prepreg

Patent metadata

Field	Value
Publication number	US-11458696-B2
Application number	US-202016843312-A
Country	US
Kind code	B2
Filing date	Apr 8, 2020
Priority date	Apr 3, 2018
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

A thermoplastic prepreg includes a mat, web, or fabric of fibers and hollow glass microspheres that are positioned atop the mat, web, or fabric of fibers or dispersed therein. The thermoplastic prepreg also includes a thermoplastic polymer that is fully impregnated through the mat, web, or fabric of fibers and the hollow glass microspheres so that the thermoplastic prepreg has a void content of less than 3% by volume of the thermoplastic prepreg. The thermoplastic material is polymerized monomers and oligomers in which greater than 90% by weight of the monomers or oligomers react to form the thermoplastic material.

First claim

What is claimed is:

1. A system for manufacturing a thermoplastic prepreg, the system comprising:
a double belt mechanism that includes an upper belt and a lower belt, the upper belt being positioned atop the lower belt to compress a fiber mat or web that is passed through the double belt mechanism and the lower belt having a longitudinal length that is substantially longer than the upper belt;
a resin applicator that is positioned atop the lower belt and that is configured to apply monomers or oligomers to the fiber mat or web as the fiber mat or web is moved past the resin applicator, wherein the monomers or oligomers are polymerizable to form a thermoplastic polymer;
an application mechanism that is positioned atop the lower belt and that is configured to apply a light weight filler material to the fiber mat or web as the fiber mat or web is moved past the application mechanism; and
a curing oven that is configured to effect polymerization of the monomers or oligomers and thereby form the thermoplastic polymer as the fiber mat or web is moved through the curing oven;
wherein:
the fiber mat or web includes chopped fibers; and
the double belt mechanism compresses the fiber mat or web and the applied monomers or oligomers as these materials are passed through the curing oven such that the monomers or oligomers fully saturate the fiber mat or web and thereby effect a full impregnation of the fiber mat or web with the thermoplastic polymer upon polymerization of the monomers or oligomers.

2. The system of claim 1 , wherein the lightweight filler material consists of hollow glass microspheres.

3. The system of claim 1 , wherein the lightweight filler material is disposed on a first side of the fiber mat or web.

4. The system of claim 1 , wherein the application mechanism is a powder applicator or device that is configured to apply the light weight filler material to the fiber mat or web.

5. The system of claim 4 , wherein the system further comprises a drying mechanism that is configured to remove residual moisture from the fiber mat or web as the fiber mat or web is moved past the drying mechanism, and wherein the lightweight filler material is dried in a separate drying mechanism prior to being applied via the application mechanism.

6. The system of claim 1 , further comprising a cooling mechanism that is configured to cool the thermoplastic prepreg after polymerization of the monomers or oligomers.

7. The system of claim 1 , wherein the fiber mat or web consists of a chopped fiber mesh that is formed by disposing chopped fiber strands or rovings on the lower belt of the double belt mechanism.

8. The system of claim 7 , further comprising a fiber chopper or fiber scattering unit positioned above the lower belt, the fiber chopper or fiber scattering unit being configured to disperse chopped fiber strands or rovings to form the chopped fiber mesh, wherein the fiber chopper or fiber scattering unit is positioned so that as the chopped fiber strands or rovings are dispersed, the chopped fiber strands or rovings fall atop the lower belt and form the chopped fiber mesh.

9. The system of claim 7 , wherein prior to application of the monomers or oligomers, the chopped fiber mesh does not include a binder that bonds or adheres the chopped fibers in the chopped fiber mesh together.

10. The system of claim 7 , wherein the chopped fiber strands or rovings comprises multiple fiber types or fiber sizes, and wherein the chopped fiber strands or rovings fall atop the lower belt so that the multiple fiber types or fiber sizes homogenously mix to form a hybrid fiber mesh.

11. The system of claim 1 , further comprising a roller around which a fabric or nonwoven mat roll is positioned, wherein the system is configured to unwind the fabric or nonwoven mat from the roller atop the lower belt so that the chopped fibers are positioned above or below the fabric or nonwoven mat and form a layered or hybrid fiber mesh comprising the chopped fibers and the fabric or nonwoven mat, wherein the layered or hybrid fiber mesh is subjected to the resin applicator and the curing oven such that the monomers or oligomers fully saturate the layered or hybrid fiber mesh and the thermoplastic polymer fully impregnates the layered or hybrid fiber mesh upon polymerization of the monomers or oligomers.

12. The system of claim 1 , further comprising a mixing component that mixes the monomers or oligomers with at least one of a catalyst and an activator, wherein the catalyst and activator facilitate in polymerizing the monomers or oligomers to form the thermoplastic polymer.

13. The system of claim 1 , further comprising a cutting mechanism that cuts the thermoplastic prepreg into sheets, the cutting mechanism being positioned after the curing oven.

14. The system of claim 1 , wherein the system further comprises a first fiber chopper that is configured to cut first fiber strands or rovings to form a first chopped fiber mesh atop the lower belt, and wherein the system comprises a second fiber chopper that is configured to cut second fiber strands or rovings to form a second chopped fiber mesh atop the first chopped fiber mesh and thereby form a layered or hybrid fiber mesh.

15. The system of claim 1 , wherein the lightweight filler material or the fibers of the fiber mat or web include a sizing composition having a coupling agent that promotes bonding between the lightweight filler material or the fibers and the thermoplastic polymer.

16. The system of claim 1 , wherein the fiber mat or web includes glass fibers, carbon fibers, basalt fibers, metal fibers, ceramic fibers, natural fibers, synthetic organic fibers, aramid fibers, inorganic fibers, or combinations thereof.

17. The system of claim 1 , wherein the monomers or oligomers comprises lactams, lactones, cyclic butylene terephthalate (CBT), MMA, precursors of thermoplastic polyurethane, or mixtures thereof.

18. The system of claim 17 , wherein the lactams comprise caprolactam, laurolactam, or mixtures thereof.

19. The system of claim 1 , wherein the thermoplastic polymer consists of thermoplastic polyurethane (TPU).

20. A system for manufacturing a thermoplastic prepreg, the system comprising:
a double belt mechanism that includes an upper belt and a lower belt, the upper belt being positioned atop the lower belt to compress a fiber mat or web that is passed through the double belt mechanism and the lower belt having a longitudinal length that is substantially longer than the upper belt;
a resin applicator that is positioned atop the lower belt and that is configured to apply monomers or oligomers to the fiber mat or web as the fiber mat or web is moved past the resin applicator, wherein the monomers or oligomers are polymerizable to form a thermoplastic polymer; and
a curing oven that is configured to effect polymerization of the monomers or oligomers and thereby form the thermoplastic polymer as the fiber mat or web is moved through the curing oven;
wherein:
the fiber mat or web includes chopped fibers;
the resin applicator is further configured to apply a lightweight filler material atop the fiber mat or web;
the lightweight filler material is hollow glass microspheres;
the hollow glass microspheres are added to the monomers or oligomers such that the hollow glass microspheres are applied to the fiber mat or web simultaneously with the monomers or oligomers; and
the double belt mechanism compresses the fiber mat or web and the applied monomers or oligomers as these materials are passed through the cur

Assignees

• Johns Manville

Inventors

• Zhang Mingfu
• Asrar Jawed

Classifications

• C08J5/242

  using metal fibres · CPC title

• B05D3/0227

  with IR heaters · CPC title

• B29L2009/00

  Layered products · CPC title

• C08J5/246

  using polymer based synthetic fibres · CPC title

• C08J5/041

  with metal fibres · CPC title