Process for making elastomeric hose

Claim 1

A process for producing a composite elastromeric hose of one or more thermosetable materials and of reduced thermal conductivity, said hose having an inner tube vulcanized to a radially expanded outermost cover including a porous network formed therein, said process comprising the steps of: (a) providing a first forming composition for forming said inner tube, said first forming composition including a thermosetable elastomer; (b) providing a second forming composition for forming said radially expanded outermost cover, said second forming composition including a thermosetable elastomer and a blowing agent; (c) forming said first forming composition into a first uncured tubular structure; (d) forming said second forming composition into a second uncured tubular structure; (e) disposing said second uncured tubular structure about said first uncured tubular structure to form an uncured hose structure of initial transverse external size determined by said second uncured tubular structure; and (f) vulcanizing said uncured hose structure to form said hose in a heated environment and in the absence of external constraint while activating said blowing agent to expand said second tubular structure radially outwardly to a final transverse external size substantially greater than said initial transverse external size to form said porous network within said outer cover during said vulcanizing thereof.