| abstract |
1,169,601. Making porous P.T.F.E. sheets. AMERICAN CYANAMID CO. 25 Jan., 1967, No. 3814/67. Heading B5A. [Also in Divisions C3 and H1] Wettable, porous, unsintered, completely fibrillated, normally liquid - impermeable P.T.F.E. sheet is made by admixing an aqueous dispersion of P.T.F.E. particles of range of diameter of from 0À05 Á-1À0 Á with a viscous, solvent-extractable resin, milling the formed mixture until the particles are fibrillated, extruding the milled product to form a sheet and solvent extracting the resin from the formed sheets. Shaping may be by injection moulding calendering. The sheets are finally rinsed with alcohol, washed with de-ionized water and dried by rolling between blotting paper. |