Method of imparting latent crimp in polyolefin synthetic fibers
OwnerEckhard C. A. Schwarzinventor
Life of this patent
Estimating the term…
Abstract
In a non-friction texturing process, the filaments of a thermoplastic polymer yarn are heated along spaced zones to form a latent crimp in the filament. The filaments are then drawn and are subsequently heated above the glass transition temperature of the polymer while the filaments are under low enough tension to allow the crimp to form. The heating along spaced zones is preferably accomplished by passing the filaments over a heated rotating grooved roll.
Claims11
A method of forming latent crimp in synthetic thermoplastic addition polymers such as polyethylene and polypropylene, comprising the steps of:
- A. heating discrete spaced zones on one side of molecularly orientable filaments, to a temperature from about 100.degree.to about 280.degree.C for a time in seconds which is equal to X times denier per filament, where X is a value which falls within the range of 0.001 to 0.00001 and wherein the centers of said zones are spaced from 2 to 50 times the filament thickness, said heating of said zones being effected by guiding the filaments about a rotating heated grooved roll having circumferentially spaced lands generally parallel to the roll axis with the lands spaced 2 to 50 times the thickness of the filament;
- B. subsequently subjecting said filaments to molecular orientation by stretching them to a percent stretch which is at least (0.006/birefringence) - 0.5, by guiding the filaments at a first velocity rate over the grooved roll and drawing the filaments away from the grooved
A method of forming latent crimp in synthetic thermoplastic addition polymers such as polyethylene and polyproplyene, comprising the steps of:
- A. heating discrete spaced zones on one side of molecularly orientable filaments, to a temperature from about 100.degree. to about 280.degree.C for a time in seconds which is equal to X times denier per filament, where X is a value which falls within the range of 0.001 to 0.00001,and wherein the centers of said zones are spaced from 2 to 50 times the filament thickness, said heating of said zones being effected by guiding the filaments about a heated roll;
- B. subsequently subjecting said filaments to molecular orientation by stretching them to a percent stretch which is at least (0.006/birefringence) - 0.5, by guiding the filaments at a first velocity rate over the roll and drawing the filaments away from the roll at a
Dependencies are inferred from the claim text.