Reinforcement material including a porous layer made of a partially cross-linked thermoplastic polymer and associated methods

Abstract

The present invention relates to a reinforcement material including at least one fiber reinforcement associated on at least one of its faces with a porous layer, the porous layer(s) representing no more than 10% of the total weight of the reinforcement material, preferably from 0.5 to 10% of the total weight of the reinforcement material, and most preferably from 2 to 6% of the total weight of the reinforcement material, characterized in that the porous layer contains a partially cross-linked thermoplastic polymer. Another object of the invention is a precursor material of such a reinforcement material, as well as their preparation method and the methods for manufacturing a preform or a composite part from such materials.

1 . A method for preparing a reinforcement material suitable for liquid composite molding, comprising the following successive steps:
 (a) providing a fibrous reinforcement;   (b) providing at least one polymeric porous layer at least partially composed of a partially-cross-linked thermoplastic polymer;   (c) associating the fiber reinforcement with the at least one polymeric porous layer;   wherein said associating step (c) is accompanied or followed by heating the partially cross-linked thermoplastic polymeric porous layer resulting in its softening or melting, followed by cooling.   
     
     
         2 . The method of  claim 1 , further comprising the following successive step:
 (d) cross-linking at least part of the cross-linkable functions present within the thermoplastic polymer under heat, UV, gamma, or beta radiation.   
     
     
         3 . The method of  claim 1 , wherein said at least one polymeric porous layer is a porous film, a grid, a powder deposit, a fabric or a nonwoven or web.