Helical artificial turf fiber with different polymers in core and periphery
AssigneePolytex Sportbelage Produktions-GmbH
InventorsDario GROCHLA, Stephan SICK
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Abstract
Disclosed is an artificial turf fiber (204, 502-510, 804, 902-906, 1500, 1602-1618) comprising a longitudinal cross-sectional profile, the artificial turf fiber being under internal stress that causes the artificial turf fiber, upon receiving heat treatment, to assume a helical shape, wherein the core of the fiber consists of or predominantly comprises a core polymer, and wherein the periphery of the fiber consists of or predominantly comprises a cladding polymer, wherein the core polymer and the cladding polymer are different polymer materials, and wherein the core and cladding polymers are selected such that the core polymer undergoes greater shrinkage than the cladding polymer when subjected to the heat treatment.
Claims21
An artificial turf fiber comprising a longitudinal cross-sectional profile, the artificial turf fiber being under internal stress that causes the artificial turf fiber, upon receiving heat treatment, to assume a helical shape, wherein the core of the fiber consists of or predominantly comprises a core polymer, and wherein the periphery of the fiber consists of or predominantly comprises a cladding polymer, wherein the core polymer and the cladding polymer are different polymer materials, and wherein the core and cladding polymers are selected such that the core polymer undergoes greater shrinkage than the cladding polymer when subjected to the heat treatment.
2-22. (canceled)
A helical artificial turf fiber comprising a longitudinal cross-sectional profile, wherein the core of the fiber consists of or predominantly comprises a core polymer, and wherein the periphery of the fiber consists of or predominantly comprises a cladding polymer, wherein the core polymer and the cladding polymer are different polymer materials, and wherein the core and cladding polymers are selected such that the core polymer undergoes greater shrinkage than the cladding polymer when subjected to the heat treatment.
A method for manufacturing an artificial turf fiber that is under internal stress, the method comprising:
- extruding a combination of at least a core polymer and a cladding polymer into a monofilament via an extrusion nozzle into a monofilament, the monofilament having a longitudinal cross-sectional profile, in particular a cross-sectional profile with a central bulb and two wings extending from the central bulb in different directions, wherein the core and cladding polymers are selected such that the core polymer undergoes greater shrinkage than the cladding polymer when subjected to the heat treatment, wherein the extrusion is performed such that the core polymer is exclusively or predominantly located in the core of the cross-sectional fiber profile and such that the cladding polymer is exclusively or predominantly located in peripheral regions of the cross-sectional profile;
- quenching the monofilament;
- controlling equipment for processing the monofilament such that a temperature gradient is formed reproducibly in the cross-section of the monofilament;
- stretching the monofilament while the temperature gradient is present to form the monofilament into the artificial turf fiber, thereby introducing the internal stress into the fiber, wherein the internal stress is adapted to cause the artificial turf fiber, upon receiving heat treatment, to assume a helical shape.
Dependencies are inferred from the claim text.