Imparting anlsotropy to foams by orienting added fibers whereby said fibers become parallely aligned

Abstract

Abstract This invention relates to a method of imparting anisotropy to polymeric foams and to the resultant products. By this invention enhanced mechanical properties are produced in polymeric foams such properties being, for example, compressive yield strengths, modular tensile strengths, and the like. Importantly, other properties of enhanced value are achieved, as for example, improved thermal conductivity and enhanced burning rates. The process involved comprises mixing in liquid form various components of the foam which is to be produced in a foaming step which involves the action of the components in the presence of a foaming agent that effects the foam expansion, and mixed with these liquid mixtures is a low level concentration of relatively short fibers, one-half inch or less, the fibers being made from either an inorganic or organic material with fiber glass or aluminum fibers being preferred. The amount of such fibers is 10% or less based on the final weight of the foam, this being in reference to a foam having a density of 2 pounds per cubic foot. Foams of greater or of less density are appropriately loaded with the fibers as will appear hereinafter. An important part of this invention is the production of foams in which the added fibers are lined up in a parallel arrangement, the parallelism being to the direction of the foam expansion. As a result of the parallel alignment, a structural reinforcement occurs, there being an increase in the compressive strength. Other improved physical properties are obtained as described hereinafter.

Inventors

• 👤 Alan A. Osgood

Bibliographic Details