Artificial turf fiber with uninterrupted undulations

Abstract

Disclosed is an extruded artificial turf fiber ( 100, 800, 900, 1000, 1100 ) having an arced cross-sectional shape, the arced cross-sectional shape being defined by a boundary line consisting of uninterrupted undulations.

1 . An extruded artificial turf fiber having an arced cross-sectional shape, the arced cross-sectional shape being defined by a boundary line consisting of uninterrupted undulations. 
     
     
         2 . The fiber of  claim 1 , wherein the fiber has ends, the ends having a radius of curvature at least as large as the smallest radius defining the undulations of the boundary line of the other parts of the cross-sectional shape. 
     
     
         3 . The fiber of  claim 1 , wherein the fiber has thickenings at the fiber ends, wherein the ends are connected to the center of the fiber via fiber arms, wherein the diameter of each of the thickenings is thicker than the thickest part of the fiber arm that connects said end to the center of the fiber. 
     
     
         4 . The fiber of  claim 1 ,
 wherein the arced cross-sectional shape has an outer, convex boundary line and an inner, concave boundary line,   wherein at least 70%, in particular at least 80%, e.g., 100% of the undulations of the outer boundary line are defined by first circles having the same first diameter; and   wherein at least 70%, in particular at least 80%, e.g., 100% of the undulations of the outer boundary line are defined by second circles having the same second diameter.   
     
     
         5 . The fiber of  claim 4 , wherein the first and second diameter are identical or similar, wherein a similar diameter lies in a range of plus or minus 10% of the other diameter. 
     
     
         6 . The fiber of  claim 4 , wherein the fiber comprises a thickening at its center which forms a rounded protrusion to at least one side of the fiber, the curvature of the protrusion being defined by a circle having a radius selected such that a ratio of the said radius to the radius of the first circles is in the range of 1.40 to 1.80, in particular 1.50 to 1.70, in particular 1.55 to 1.68. 
     
     
         7 . The fiber of  claim 1 ,
 wherein the cross-section of the fiber is shaped like the arc of a segment of a circle having a radius referred to as “fiber profile circle radius”,   wherein the ratio of the width of the fiber profile and the fiber profile radius is in the range of 1.40 to 1.80, in particular 1.50 to 1.70, in particular 1.55 to 1.68.   
     
     
         8 . The fiber of  claim 1 , wherein the fiber has ends, the ends being connected to the center of the fiber via fiber arms, wherein each of the fiber arms is formed such that over a portion of at least 80% of the length of that arm, the fiber arm thickness has a thickness which is no more than 15% thicker or thinner than the average thickness of that fiber arm portion. 
     
     
         9 . The fiber of  claim 1 , wherein the fiber comprises a nucleating agent. 
     
     
         10 . The fiber of  claim 1 , wherein the cross-section of the fiber is shaped like the arc of a segment of a circle or an ellipse. 
     
     
         11 . The fiber of  claim 1 , wherein the cross-section of the fiber is shaped like a catenary. 
     
     
         12 . The fiber of  claim 1 , wherein the fiber comprises a thickening at its center. 
     
     
         13 . The fiber of  claim 12 ,
 wherein the thickening at its center is formed such that a round bulge is formed towards the outer surface of the fiber,   wherein the thickening does not lead to a bulge towards the inner surface of the fiber.   
     
     
         14 . The fiber of  claim 1 , wherein the fiber has a width measured as a straight line connecting the first and second ends of 0.7 to 2.5 mm, in particular of 0.9 to 1.5 mm. 
     
     
         15 . The fiber of  claim 1 , wherein the undulations are formed such that the fiber has at least 6, in particular at least 7, in particular 7-11, e.g., 9 round bulges on its outer surface, and/or such that the fiber has at least 6, in particular 6-10, e.g., 8 round bulges on its inner surface. 
     
     
         16 . The fiber of  claim 1 , wherein the majority of undulations form consecutive, pairs of a round bulge and a round indentation, wherein each pair has a length of 0.10 mm to 0.30 mm, e.g. 0.10 to 0.20 mm. 
     
     
         17 . The fiber of  claim 1 , wherein at least 70% of the undulations of the inner surface and at least 70% of the outer surface have the same or a similar undulation length, wherein an undulation length is similar to a given length if it differs no more than plus or minus 10% from said given length. 
     
     
         18 . An artificial turf comprising:
 a carrier; and   a plurality of artificial turf fibers integrated into the carrier and protruding therefrom to form an artificial turf, the fibers each having an arced cross-sectional shape, the arced cross-sectional shape being defined by a boundary line consisting of uninterrupted undulations.