polymer blend composition having improved processibility and comprising : a major portion of a difficultly melt - processible polymer , and a minor portion of : at least an effective amount , to improve processibility , of a fluorocarbon copolymer which at the melt - processing temperature of is either in a melted form if crystalline , or is above its glass transition temperature if amorphous , and at least an effective amount , to improve processibility , of at least one tetrafluoroethylene homopolymer or copolymer of tetrafluoroethylene and at least one monomer copolymerizable therewith , wherein the mole ratio of fluorine to hydrogen is at least 1 : 1 , and which is solid at the melt - processing temperature of ; masterbatches comprised of the processing aid ; and processes utilizing the processing aid .