Method and apparatus for producing crimped thermoplastics
First Claim
1. A method for producing a continuous filament by extrusion of molten thermoplastic material through a spinneret plate having holes of a cross-sectional configuration that is determinative of the cross-section of the formed filament, the method comprising the steps of generating a turbulence in the molten thermoplastic material intended to form the filament, immediately prior to, or at the point of, formation of the filament, whilst the thermoplastics material is in its glass transition phase and maintaining stresses induced in the formed filament by said turbulence whilst the filament material passes into its crystallised phase;
- andforming filaments having a substantial helical crimp by extruding the molten thermoplastic material through holes in the spinneret plate.
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Accused Products
Abstract
A method for producing a substantial helical crimp in a continuous filament of thermoplastic material by generating a turbulence in the thermoplastic material while the material is in its glass transition phase and maintaining stresses induced in the formed filament by said turbulence while the material passes into its crystallized phase.
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Citations
21 Claims
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1. A method for producing a continuous filament by extrusion of molten thermoplastic material through a spinneret plate having holes of a cross-sectional configuration that is determinative of the cross-section of the formed filament, the method comprising the steps of generating a turbulence in the molten thermoplastic material intended to form the filament, immediately prior to, or at the point of, formation of the filament, whilst the thermoplastics material is in its glass transition phase and maintaining stresses induced in the formed filament by said turbulence whilst the filament material passes into its crystallised phase;
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forming filaments having a substantial helical crimp by extruding the molten thermoplastic material through holes in the spinneret plate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 16)
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- 11. A spinneret for use in thermoplastic material extrusion, said spinneret having a spinneret plate that is provided with a plurality of holes characterized in that said holes generate a turbulence in the thermoplastic material while in its glass transition phase as it is extruded through said spinneret.
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17. A method for producing a continuous filament by extrusion of molten thermoplastic material through a spinneret plate having holes of a cross-sectional configuration that is determinative of the cross-section of the formed filament, the method comprising the steps of generating a turbulence in the molten thermoplastic material whilst the thermoplastics material is in its glass transition phase and maintaining stresses induced in the formed filament by said turbulence whilst the filament material passes into its crystallised phase;
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forming filaments having a substantial helical crimp by extruding the molten thermoplastic material through holes in a spinneret plate wherein each hole makes an angle to an external face of the spinneret plate. - View Dependent Claims (18)
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19. A method for producing a continuous filament by extrusion of molten thermoplastic material through a spinneret plate having holes of a cross-sectional configuration that is determinative of the cross-section of the formed filament, the method comprising the steps of generating a turbulence in molten thermoplastic material intended to form the filament, whilst the thermoplastic material is in its glass transition phase and maintaining stresses induced in the formed filament by said turbulence whilst the filament material passes into its crystallised phase;
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forming filaments by extruding the molten thermoplastic material through the spinneret plate wherein the turbulence in the molten thermoplastic material is generated by a change in the cross-sectional area of each hole through the spinneret plate. - View Dependent Claims (20)
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21. A spinneret for use in thermoplastic material extrusion, said spinneret having a plate that is provided with a plurality of holes characterized in that the cross-sectional area of each of said holes through the spinneret plate has a cross-sectional area through the plate that is in the form of a step so as to generate a turbulence in the thermoplastic material while in its glass transition phase as it is extruded through said spinneret.
Specification