Artificial turf and production method

Patent metadata

Field	Value
Publication number	US-11987939-B2
Application number	US-202117539551-A
Country	US
Kind code	B2
Filing date	Dec 1, 2021
Priority date	Mar 27, 2014
Publication date	May 21, 2024
Grant date	May 21, 2024

Abstract

The invention provides for a method of manufacturing artificial turf (1000). The method includes creating a polymer mixture, such as polymer mixture (400), where the polymer mixture is at least a three-phase system. The polymer mixture includes a first polymer, a second polymer and a compatibilizer. The first polymer is a polyamide (PA) and the second polymer is a polyethylene (PE). The first polymer is included in an amount of 0.125 percent to 5 percent by weight, the second polymer is included in an amount of 60 percent to 97 percent by weight and the compatibilizer is included in an amount of 0.375 percent to 15 percent by weight. The first polymer and the second polymer are immiscible, and the first polymer forms polymer beads surrounded by the compatibilizer within the second polymer.

First claim

The invention claimed is:

1. A method of manufacturing artificial turf, the method comprising:
creating a polymer mixture, wherein the polymer mixture is at least a three-phase system, wherein the polymer mixture comprises a first polymer, a second polymer, and a compatibilizer, wherein the first polymer comprises polyamide and the second polymer comprises polyethylene, wherein the first polymer is included in an amount of 0.25 percent to 2.5 percent by weight, wherein the second polymer consists of:
55 percent to 70 percent by weight of a first linear low-density polyethylene (LLDPE), the first LLDPE having a melt flow rate from about 0.9 g/10 min to about 1.1 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg,
10 percent to 20 percent by weight of a second LLDPE, the second LLDPE having a melt flow rate from about 2.2 g/10 min to about 2.4 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg, and
8 percent to 14 percent by weight of a high-density polyethylene (HDPE), the HDPE having a melt flow rate from about 3.9 g/10 min to about 4.1 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg,

wherein the compatibilizer is included in an amount of 0.75 percent to 7.5 percent by weight, wherein the polymer mixture further comprises 4 percent to 11 percent by weight of a polymer protection mixture comprising at least one of a hindered amine light stabilizer, an anti-oxidant, an oxygen scavenger, a third LLDPE, fillers and pigments, and 0.15 percent to 0.75 percent by weight of a processing aid additive, wherein the processing aid additive comprises a fluoropolymer based processing additive or a siloxane, wherein the first polymer and the second polymer are immiscible, and wherein the first polymer forms polymer beads surrounded by the compatibilizer within the second polymer;
extruding the polymer mixture into a monofilament;
quenching the monofilament;
reheating the monofilament;
stretching the reheated monofilament to deform the polymer beads into fibrous regions and to form the monofilament into an artificial turf fiber, the fibrous regions including the first polymer, the fibrous regions being at least partially surrounded by the compatibilizer and separated from the second polymer by the compatibilizer, and the fibrous regions being centrally located such that the fibrous regions do not delaminate after formation; and
incorporating the artificial turf fiber into an artificial turf backing,
wherein the extruding comprises extruding the polymer mixture into the monofilament including a round bulge and two protrusions extending from the round bulge, wherein the fibrous regions are centrally located throughout the round bulge and the two protrusions.

2. The method of claim 1 , wherein the compatibilizer comprises an ethylene ethyl acrylate.

3. The method of claim 1 , wherein a weight ratio of the first LLDPE to the second LLDPE is between 1:20 and 1:3, and wherein the melt flow rate of the mixture of the first LLDPE and the second LLDPE is from about 1.95 g/10 min to about 2.25 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg.

4. The method of claim 1 , wherein the polymer beads comprise crystalline portions and amorphous portions, wherein stretching the polymer beads into the fibrous regions causes an increase in the size of the crystalline portions relative to the amorphous portions.

5. The method of claim 1 , wherein the creating of the polymer mixture comprises:
forming a first mixture by mixing the first polymer with the compatibilizer;
heating the first mixture;
extruding the first mixture;
granulating the extruded first mixture;
mixing the granulated first mixture with the second polymer; and
heating the granulated first mixture with the second polymer to form the polymer mixture.

6. The method of claim 1 , wherein the first polymer and the second polymer are polymers formed from renewable resources.

7. The method of claim 1 , wherein the two protrusions extend from the round bulge in opposite directions.

8. The method of claim 7 , wherein a profile of at least one of the protrusions comprises a concave side.

9. An artificial turf manufactured according to the method of claim 1 .

10. The artificial turf of claim 9 , wherein the artificial turf fiber extends a predetermined length beyond the artificial turf backing, and wherein the fibrous regions have a length less than one half of the predetermined length.

11. An artificial turf comprising:
an artificial turf backing; and
an artificial turf yarn including a plurality of fibers, each of the plurality of fibers including a round bulge, two protrusions extending from the round bulge, and a polyamide fibrous region substantially surrounded by a compatibilizer comprising an ethylene ethyl acrylate and by polyethylene, the compatibilizer being situated between the polyamide and the polyethylene such that the fibrous regions are centrally located throughout the round bulge and the two protrusions and do not delaminate,
wherein the polyamide is included in an amount of 0.25 percent to 2.5 percent by weight,
wherein the polyethylene consists of:
55 percent to 70 percent by weight of a first linear low-density polyethylene (LLDPE), the first LLDPE having a melt flow rate from about 0.9 g/10 min to about 1.1 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg,
10 percent to 20 percent by weight of a second LLDPE, the second LLDPE having a melt flow rate from about 2.2 g/10 min to about 2.4 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg, and
8 percent to 14 percent by weight of a high-density polyethylene (HDPE), the HDPE having a melt flow rate from about 3.9 g/10 min to about 4.1 g/10 min as measured in accordance with DIN EN ISO 1133 190° C./2.16 kg,

wherein the compatibilizer is included in an amount of 0.75 percent to 7.5 percent by weight,
wherein each of the plurality of fibers further comprises 4 percent to 11 percent by weight of a polymer protection mixture comprising at least one of a hindered amine light stabilizer, an anti-oxidant, an oxygen scavenger, a third LLDPE, fillers and pigments, and 0.15 percent to 0.75 percent by weight of a processing aid additive, wherein the processing aid additive comprises a fluoropolymer based processing additive or a siloxane.

Assignees

• Polytex Sportbelage Produktions Gmbh
• Polytex Sportbelaege Produktions—Gmbh

Inventors

• Sick Stephan

Classifications

• E01C13/08 Primary

  Surfaces simulating grass {; Grass-grown sports grounds (grass-like surfaces for skiing E01C13/12)} · CPC title

• B29C48/0018

  combined with shaping by orienting, stretching or shrinking, e.g. film blowing (B29C48/0017 takes precedence) · CPC title

• B29C48/022

  characterised by the choice of material · CPC title

• B29C48/05

  Filamentary, e.g. strands · CPC title

• B29C48/21

  the layers being joined at their surfaces · CPC title