Preconsolidation process for making fluoropolymer composites

• US 5,232,975 A
• Filed: 01/16/1992
• Issued: 08/03/1993
• Est. Priority Date: 01/16/1992
• Status: Expired due to Term

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Deakyne, Clifford K.
• Primary Examiner(s): Michl, Paul R.
• Assistant Examiner(s): DeWitt, LaVonda R.
• Application Number:
  US07/821,568
• Time in Patent Office: 565 Days
• Field of Search: 523/220, 523/307, 524/495, 524/496, 524/545, 524/546, 264/108, 264/321
• US Class Current: 524/495
• CPC Class Codes: B29C 43/203 Making multilayered articles
• CPC Class Codes: B29C 70/14 oriented
• CPC Class Codes: B29C 70/465 and impregnating by melting a solid material, e.g. sheets, powders of fibres
• CPC Class Codes: B29K 2027/12 containing fluorine
• CPC Class Codes: B29K 2307/00 Use of elements other than metals as reinforcement
• CPC Class Codes: C08J 2327/12 containing fluorine atoms
• CPC Class Codes: C08J 5/04 Reinforcing macromolecular compounds with loose or coherent fibrous material

Abstract

A process for preconsolidating a planar porous fiber-thermoplastic resin layer which is unconstrained in the inplane directions by heating the layer to above the melting point of the resin, then applying pressure to the plane of the layer causing resin flow, thus orienting the fibers in the plane of the layer.

Claims

1. A process for preconsolidating a porous thermoplastic resin-fiber planar layer comprising:

heating said preform layer to above the melt temperature of the thermoplastic resin;

applying sufficient pressure normal to the plane of the layer while the layer is unconstrained in the in-plane directions to cause the molten resin to flow;

orienting said fibers in substantially the plane of the layer by means of said flow to form a preconsolidated sheet; and

cooling said sheet under pressure.

2. The process of claim 1 wherein said thermoplastic resin is a fluoropolymer and said fibers are carbon.

3. The process of claims 1 or 2 including forming a solid shaped composite from a stack of said sheets by heating said stack to a high enough temperature and applying sufficient pressure for a sufficient amount of time to form said solid shaped composite.