Felt-like LAYERED COMPOSITE MATERIALS of polytetrafluoroethylene and GLASFIBER PAPER

摘要

A felt-layered composite of the following structure:… a. a first layer (1) of a predominantly horizontal coplanar superimposed layers of filamentary polytetrafluoroethylene components interrupted by occasional interlayered orientation;… b. a thin high density nonwoven layer (2) of fine glass staple fibres;… c. a scrim fabric (3) of polytetrafluoroethylene fibres and… d. a second predominantly horizontal coplanar superimposed layers (2) of filamentary polytetrafluoroethylene components interrupted by occasional interlayer orientation;… wherein the layers are mechanically bonded together by filamentary polytetrafluoroethylene components extending vertically throughout the composite and a process for making this composite; the composite is useful as a filter fabric and is primarily used for bag filters to remove fly ash from the gaseous combustion products of coal fired furnaces and boilers.