Dispersion spinning process for polytetrafluoroethylene and related polymers
AssigneeE. I. Du Pont de Nemours and Company
InventorsNicole Lee Blankenbeckler, Joseph Michael Donckers, II, Warren Francis Knoff
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Abstract
A process for spinning a fully water washed fluorinated olefinic polymer intermediate fiber structure from a mixture of an aqueous dispersion of particles of the fluorinated olefinic polymer and a solution of a cellulosic ether.
Claims7
A process for spinning a fully water washed fluorinated olefinic polymer intermediate fiber from a mixture of an aqueous dispersion of particles of the fluorinated olefinic polymer and a solution of a matrix polymer comprising the steps of:
- (a) forming a mixture of the aqueous dispersion of the fluorinated olefinic polymer particles and the solution of the matrix polymer wherein the matrix polymer is a cellulosic ether having a degree of substitution that is no more than about 0.5 and no less than about 0.02;
- (b) extruding the mixture into a coagulation solution containing salts, acids or mixtures thereof to coagulate the matrix polymer and to form an intermediate fiber structure;
- and
- (c) washing the intermediate fiber structure in sufficient near neutral pH water to substantially remove from the fiber structure salts, acids and mixtures thereof
- wherein the washed fiber structure has a self supporting length of at least 30 cm and is substantially free of ions.
A process for forming a fully water washed fluorinated olefinic polymer intermediate article from a mixture of an aqueous dispersion of particles of the fluorinated olefinic polymer and a solution of a matrix polymer comprising the steps of:
- (a) forming a mixture of the aqueous dispersion of the fluorinated olefinic polymer particles and the solution of the matrix polymer wherein the matrix polymer is a cellulosic ether having a degree of substitution that is no more than about 0.5 and no less than about 0.02;
- (b) extruding the mixture into a coagulation solution containing salts, acids or mixtures thereof to coagulate the matrix polymer and to form the intermediate article;
- and
- (c) washing the intermediate article in sufficient near neutral pH water to substantially remove from the fiber structure salts, acids or mixtures thereof and other impurities.
Dependencies are inferred from the claim text.