System for producing a fully impregnated thermoplastic prepreg

Patent metadata

Field	Value
Publication number	US-2019299546-A1
Application number	US-201816172153-A
Country	US
Kind code	A1
Filing date	Oct 26, 2018
Priority date	Apr 3, 2018
Publication date	Oct 3, 2019
Grant date	—

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, web, or fabric 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 drying mechanism that is configured to remove residual moisture from the fiber mat, web, or fabric as the fiber mat, web, or fabric is moved past the drying mechanism; 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, web, or fabric as the fiber mat, web, or fabric is moved past the application mechanism; a resin application die that is positioned atop the lower belt and that is configured to apply monomers or oligomers to the fiber mat, web, or fabric as the fiber mat, web, or fabric is moved past the resin application die, 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, web, or fabric and lightweight filler material are moved through the curing oven; wherein the double belt mechanism compresses the fiber mat, web, or fabric, the lightweight filler material, 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, web, or fabric and lightweight filler material and thereby effect a full impregnation of the fiber mat, web, or fabric and lightweight filler material 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 , further comprising a gas application mechanism that is positioned to blow a moisture-free gas onto one or more surfaces of the fiber mat, web, or fabric in order to substantially prevent exposure of the monomers or oligomers to ambient moisture in a surrounding environment.

4 . The system of claim 1 , wherein the fiber mat, web, or fabric comprises a fabric or a nonwoven mat and wherein the lightweight filler material is disposed on a first side of the fabric or nonwoven mat.

5 . The system of claim 1 , wherein the application mechanism is positioned before the drying mechanism so that the drying mechanism removes residual moisture from both the fiber mat, web, or fabric and the lightweight filler material as the fiber mat, web, or fabric and the lightweight filler material is moved past the drying mechanism.

6 . The system of claim 5 , where in the lightweight filler material is dried in a separate drying mechanism prior to being applied via the application mechanism.

7 . 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.

8 . The system of claim 1 , wherein the fiber mat, web, or fabric comprises chopped fiber mesh that is formed by disposing chopped fiber strands on the lower belt of the double belt mechanism.

9 . The system of claim 8 , further comprising a fiber chopper positioned above the lower belt, the fiber chopper being configured to cut fiber strands or bundles to form chopped fibers, wherein the fiber chopper is positioned so that as the fibers strands or bundles are cut, the chopped fibers fall atop the lower belt and form a web or mesh of chopped fibers.

10 . The system of claim 1 , wherein the fiber mat, web, or fabric comprises a fabric, a nonwoven mat, a web of chopped fibers, or combinations thereof, and wherein the lightweight filler material is disposed at least partially within the fiber mat, web, or fabric.

11 . 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, web, or fabric.

12 . The system of claim 1 , wherein:
the resin application die is the application mechanism that applies the lightweight filler material atop the fiber mat, web, or fabric; the lightweight filler material is hollow glass microspheres, and the hollow glass microspheres are added to the monomers or oligomers such that the hollow glass microspheres are applied to the fiber mat, web, or fabric simultaneously with the monomers or oligomers.

13 . The system of claim 12 , further comprising a powder applicator or device that is configured to apply the hollow glass microspheres to the fiber mat, web, or fabric such that the hollow glass microspheres are applied to the fiber mat, web, or fabric via the resin application die and the powder applicator or device.

14 . 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.

15 . 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.

16 . The system of claim 14 , wherein the mixing component and the resin application die are heated to maintain a temperature of the monomers or oligomers within a temperature range above the melting point of the monomers or oligomers prior to applying the monomer or oligomers to the fiber mat, web, or fabric.

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

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

19 . 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.

20 . The system of claim 19 , wherein the lactams comprise caprolactam, laurolactam, or mixtures thereof.

21 . The system of claim 1 , wherein the double belt mechanism and the curing oven are components of a double belt oven.

22 . A method of forming a thermoplastic prepreg comprising:
moving a fiber mat, web, or fabric atop a lower belt of a double belt press mechanism; drying the fiber mat, web, or fabric via a drying mechanism to remove residual moisture from the fiber mat, web, or fabric; applying a lightweight filler material to the fiber mat, web, or fabric via an application mechanism that is positioned atop the lower belt as the fiber mat, web, or fabric is moved past the application mechanism; applying monomers or oligomers to the fiber mat, web, or fabric via a resin application die that is positioned atop the lower belt; passing the fiber mat, web, or fabric, the lightweight filler material, and the applied monomers or oligomers between the lower belt and an upper belt of the double belt press mechanism to press the monomers or oligom

Assignees

• Johns Manville

Inventors

• Zhang Mingfu
• Asrar Jawed

Classifications

• B29B15/127

  by spraying · CPC title

• C08J2377/02

  Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08J2377/10 takes precedence) · CPC title

• C08J5/043

  with glass fibres · CPC title

• B29K2101/12

  Thermoplastic materials · CPC title

• B29K2105/0872

  Prepregs · CPC title