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US 4,344,908 AGranted
Process for making polymer filaments which have a high tensile strength and a high modulus
AssigneeStamicarbon B.V.
InventorsPaul Smith, Pieter J. Lemstra
Life of this patent
Estimating the term…
Abstract
A process for making polymer filaments which have a high tensile strength and a high modulus by stretching a polymer filament which contains an appreciable amount of polymer solvent at a temperature between the swelling point and the melting point of the polymer.
Claims8
A process for making polymer filaments which have a high tensile strength and a high modulus comprising the steps of,
- (a) spinning a solution of a polymer, ranging from about 1% to about 5% by weight of polymer to solvent, through a spinning aperture to form a filament,
- (b) cooling said filament of step (a) to below the solution temperature of the polymer either in a zone containing a gas without promoting the evaporation of the solvent or with a cooling liquid that does not dilute or extract the solvent in the filament,
- (c) bringing said filament to a temperature between the swelling point of the polymer in the solvent and the melting point of the polymer and,
- (d) stretching the filament that still contains at least about 25% by weight of solvent relative to the polymer, at a stretching ratio of at least 5.
1 more element
A process for making polymer filaments which have a high tensile strength and a high modulus comprising the steps of,
- (a) spinning a solution of polymer ranging from about 1% to about 5% by weight of polymer to solvent through a spinning aperture to form a filament,
- (b) cooling said filament of step (a) to below the solution temperature of the polymer to form a polymer gel in either a zone containing a gas without promoting the evaporation of the solvent or with a cooling liquid that does not dilute or extract the solvent in the filament,
- (c) adjusting the temperature of said polymer gel filament to a value between the swelling point of the polymer and the melting point of the polymer,
- (d) stretching the filament, that still contains at least about 25% by weight of solvent relative to the polymer, at a stretching ratio of at least 5, wherein there is at least a partial evaporation of the solvent, and
- (e) recovering a substantially solvent-free filament.
2 more elements
Dependencies are inferred from the claim text.