heretofore , the only practical way known to decrease the viscosity of an ionically thickened tetrafluoroethylene polymer dispersion has been by diluting it with water . this decreases the solids level , which can have an undesirable effect on subsequent processing . it has now been discovered that if the tetrafluoroethylene polymer dispersion contains a sodium phosphate in which the ratio of na 2 o to p 2 o 5 is between 1 : 1 and 3 : 1 , the viscosity of the dispersion can be decreased by adding selected inorganic electrolytes .