Process for preparing polytetrafluoroethylene granular powder

Polytetrafluoroethylene granular powder made by the process which comprises agitating a finely divided polytetrafluoroethylene powder composed of primary particles having an average particle size of 1 to 200.mu. to agitation in an aqueous medium consisting of water and an organic liquid having a surface tension of at most 35 dynes/cm. at 25.degree. C., said organic liquid being incompatible with water in an apparatus to form agglomerates, by passing said agglomerates through a crushing mechanism and continuously recycling said crushed agglomerates through said apparatus and mechanism for further agitation and crushing, said crushing mechanism being capable of lowering an average particle size of the agglomerates composed of said primary particles having an average particle size of 1 to 200.mu. by partially crushing large agglomerated particles having an improperly large particle size or abnormally large aggregates, said organic liquid being employed in an amount of 20 to 300% by weight and water being employed in an amount of at least 130% by weight and said aqueous medium being employed in an amount of 150 to 5000% by weight, respectively, relative to said finely divided polytetrafluoroethylene, to give said polytetrafluoroethylene granular powder consisting essentially of agglomerates composed of said primary particles and being substantially spherical, in which at least 90% by weight of the entire agglomerated powder has a particle size of at most 1000.mu. and an average particle size of said agglomerate powder falls in the range of 100 to 500.mu. and at least 60% by weight of the agglomerated powder has a particle size of 0.7 to 1.3 times said average particle size of said agglomerated powder, the powder flowability of said powder being at least 3 and the bulk density being at least 700 g./liter, and said granular powder giving a molded article having a surface roughness of at most 2.0.