Process for making a mat composed of aluminum silicate fibers and polytetrafluoroethylene

Claim 1

A PROCESS WHICH COMPRISES ADDING A HIGHLY IONIZABLE COAGULATING AGENT TO A DISPERSION OF COLLOIDAL POLYTETRAFLUOROETHYLENE IN WATER CONTAINING FIBROUS ALUMINUM SILICATE, SAID DISPERSION BEING FURTHER CHARACTERIZED IN THAT IT IS OBTAINED BY ADDING CONCENTRATED AQUEOUS COLLOIDAL POLYTETRAFLUOROETHYLENE, HAVING A POLYTETRAFLUOROETHYLENE CONTENT OF 10 TO 17% BY WEIGHT TO A FIBROUS ALUMINUM SILICATE AQUEOUS DISPERSION HAVING A FIBROUS ALUMINUM SILICATE CONTENT OF ABOUT 0.7% BY WEIGHT, SAID DISPERSION CONTAINING A CONTROLLED QUANTITY OF DISPERSING AGENT SUFFICIENT TO PREVENT COAGULATION OF THE DISPERSING EXCEPT UPON ADDITION OF SAID HIGHLY IONIZABLE MATERIAL, THE WEIGHT RATIO OF POLYTETRAFLUOROETHYLENE: FIBROUS ALUMINUM SILICATE BEING ABOUT 60:40, AGITATING THE RESULTING MIXTURE UNTIL THE SAID POLYTETRAFLUOROETHYLENE BECOMES EXHAUSTED UPON THE SAID FIBROUS ALUMINUM SILICATE, AT A PH OF ABOUT 5, THEREAFTER FORMING A MAT OF THE RESULTING FIBERS, DRYING AND SINTERING THE SAID MAT, SAID CONTROLLED QUANTITY OF DISPERSING AGENT BEING NOT IN EXCESS OF 2% BY WEIGHT, BASED ON THE WEIGHT OF SAID DISPERSION, SAID DISPERSING AGENT BEING AN ALKYL ARYL POLYETHER ALCOHOL.