PTFE fibre material and process for making it

Abstract

The invention provides a fiber material of PTFE and, optionally, hydrophilizing additives, for use in the production of diaphragms for the electrolysis of alkali chlorides, as well as for filter layers. The fiber material comprises fiber bundles and these, in turn, comprise individual microfibrils, there being irregularly shaped interstices between the microfibrils. The fiber material is produced in that a PTFE dispersion, consisting of a salt solution with PTFE particles and, optionally, hydrophilizing additives, is treated in a hot gas/vapor stream in a fluidized bed apparatus charged with inert solids. The method permits the fiber material to be produced also in larger quantities in an economic manner.

Dependencies are inferred from the claim text.