JP2022508654A - Non-uniform artificial turf filling - Google Patents

Abstract

A grass-simulating artificial turf containing a layer of dispersed, non-uniform, polyvinyl chloride-based particles with asymmetrical shapes and different sizes.

Description

(Cross-reference with related applications)
This application claims the priority benefit of US Provisional Application No. 62 / 742,539 filed October 8, 2018, which is incorporated herein by reference.

(Background of invention)
The present invention relates to artificial turf, in particular a turf filling (infill) comprising polymer particles, granules or pellets. Artificial turf is typically used for sports and athletic surfaces, but for playground turf, synthetic turf (laws), landscapes, private facilities, parks, commercial surfaces, municipal premises, test sites, etc. It can also be used for other applications that simulate grass surfaces.

Artificial turf generally contains synthetic fibers or filaments that are thread-stitched into a woven material with an adhesive lining that holds the fibers or filaments, simulating grass leaves as an upright synthetic grass layer. Natural and / or synthetic particles such as granules and pellets, including one or more of rubber, vinyl, sand, and various polymers, are usually dispersed in an upright artificial turf layer as a filler and are often turf-filled. It is called a thing. The type of filling provides the artificial turf with performance features such as impact absorption, bouncing ball, friction, ball rolling, weather resistance, and other properties specific to certain synthetic turf constructions.

Conventional synthetic filler materials are generally uniform in shape and size, such as rubber, polymers, and synthetic fillers of similar materials having the same spherical and cylindrical shape and size. U.S. Pat. It describes that it can be provided in different shapes (eg, stars, polygons, hearts, and triangles) to improve the interlocking traction and performance characteristics of artificial turf. As with other conventional filler materials, the '956 application envisions only fillers of uniform regular shape and size.

(Gist of the invention)
Embodiments of the present invention provide improvements over conventional fillers that generally have a uniform size and regular shape for the filler particle material. The present invention provides non-uniform filling pellets, granules or particles contained from PVC in artificial and synthetic turf installations.

In embodiments of the invention, the PVC filler pellets and granules dispersed as filler in the artificial turf installation will vary in size and non-compliance, such as asymmetrical shapes, to give the artificial turf improved performance characteristics. It has a regular shape. In certain embodiments, such shapes include seed-like and droplet-like shapes of different sizes. In a further embodiment, such shapes generally include elliptic, ovate and obovate shapes. In yet another embodiment, such shapes are generally biconvex and asymmetrically oval shapes (eg, pumpkin seed and sunflower seed shapes with generally pointed ends). Can be mentioned. In yet another embodiment, such shapes generally include teardrop / teardrop shapes. In various embodiments, any combination of the above-mentioned different shapes can be provided to each other in different sizes as PVC-filled granules, pellets and particles in an artificial turf installation.

FIG. 1 is a photograph of PVC-filled pellets with different irregular shapes and different sizes in embodiments of the present invention. FIG. 2 is a front view of a multi-hole extrusion die with holes of different sizes for producing PVC-filled pellets, as shown in FIG. 1 in embodiments of the present invention. FIG. 3 is an enlarged front view of the multi-hole extrusion die of FIG. 2 according to the embodiment of the present invention.

(Detailed description of the invention)
As shown in one embodiment of FIG. 1, PVC-based microparticles 5 for artificial turf fillings include a variety of non-uniform shapes and sizes. Generally, the particles are irregular, such as seeds and / or seeds with an asymmetrical shape that resembles droplets. Preferred PVC-based particles 5 for use in embodiments of the invention include such PVC granules and pellets having the composition described in '95 6 publication incorporated herein by reference. In addition, the PVC-based microparticles 5 can be produced according to conventional extrusion, pelletization and molding methods. In embodiments of the invention, PVC granules and pellets can be produced according to the methods described and / or referenced in '956 publication.

In one embodiment, the extrusion die 20 as shown in FIGS. 2 and 3 can be used to produce PVC fine particles 5 having a plurality of shapes and sizes according to the present invention. Those skilled in the art of extruding, pelletizing and molding of PVC compositions will appreciate manufacturing parameters such as execution rate, temperature setting, etc. for optimal production of PVC pellets, granules and particles as in the present invention.
It will be appreciated that it will depend on a number of factors such as the particular machine used, the particular environment for manufacture, the exact composition of the PVC-based material, and similar variables. Therefore, achieving the desired results as part of the manufacturing process for PVC-based fillers molded and sized according to the present invention is within the skill of skill in the art and is important to the present invention. Is not considered.

In one embodiment shown in FIGS. 2 and 3, the extrusion die 20 is a ring of a first hole 30, a ring of a second hole 32, a ring of a third hole 34, a ring of a fourth hole 36, and the like. Includes numerous rings of holes of different sizes. The holes are of different sizes, which can produce different non-uniform irregular shapes and different sizes of PVC fine particles 5. The configuration for holes, the number of holes, the shape of the holes, the distance between the holes, and the alignment of the holes (whether ring, grid, or other pattern) are not in the other embodiments of the invention. It will be appreciated that it can vary from the illustrated embodiments, while still supporting the formation of PVC particles 5 of various sizes that are non-uniform in the rules.

In embodiments of the invention, the use of irregular, non-uniform and varying sizes of PVC particles 5 provides the artificial turf with improved performance characteristics compared to the uniform particles disclosed in the '956 application. In the test results of Tables I-III, which will be described later, the uniform PVC-based infill particles used in the artificial turf according to the '956 application are referred to as "20s / 50TPE_PrimorArt" in the artificial turf according to the embodiment of the present invention. The non-uniform PVC filled particles used in the wear simulation are called "70/30 Pre-Wear" and are used in artificial turf run on a wear simulation machine equipped with a Lisport brand wear machine. Non-uniform PVC filled particles are called "70/30 Post-Wear".

To compare performance characteristics, 20s / 50TPE_PrimorArt, 70/30 Pre-Wear, and 70/30 Post-Wear particles, respectively, were provided on the artificial turf and subjected to the tests described below. The 20s / 50TPE_PriorityArt microparticles were provided on an artificial turf test system of 20lbs sand / 50lbs thermoplastic elastomer (TPE) on 2 1/2 turf. 70/30 Pre-Wear fine particles are 4.97 lbs / sq. ft. PVC, 2.13 lbs / sq. ft. Sand, 2.25 "slit film turf, provided in a padless artificial turf test system. 70/30 post-wear microparticles were 4.97 lbs / sq. Ft. PVC, 2.13 lbs / sq. Ft. Sand, 2.25 "slit film turf, provided in a padless artificial turf test system and subjected to a 20,000 cycle Lisport wear machine.

The following laboratory tests were performed on each sample of particulate matter / artificial turf. The technical guidelines of the Artificial Turf Council (STC) are incorporated herein by reference. An EN reference is a reference to a European standard incorporated herein by reference.

Force reduction (%)-(STC advanced artificial athlete protocol test) Measures the impact absorption given by the surface when the player at his feet is running. A low value represents a surface with a hard foot. Results are compared to STC performance guidelines of 57% to 68% in the community field and 62% to 68% in the stadium field.

Vertical Deformation (mm)-(STC Advanced Artificial Athletes Protocol Test) Measures the amount of surface compression as an athlete crosses the surface. This value is often related to the speed of play and surface stability. Results are compared to STC performance guidelines of 6 mm to 11 mm for community fields and 6 mm to 10 mm for stadium fields. Vertical deformation usually decreases over time as the field is used.

Energy Recovery (%)-(STC Advanced Artificial Athletes Protocol Test) Measure the energy returned as a percentage of the applied energy. This can be thought of as surface elasticity. This value is related to the feel of your feet and the speed of play. This measurement is not part of the official standard, but it is a useful measurement. The recommended range is 20% to 50%.

ASTM F355A Gmax / HIC Impact Damping (Flat Face Drop Missile) (G (gravity unit))-ASTM F355A Impact Hardness is an official device / method for assessing the hardness of an artificial turf playground. It is used to measure impact damping based on a given head / body impact. This is a 20-pound "missile" with a 3-axis accelerometer dropped from a height of 24 inches. The STC recommends that the Gmax value be less than 165.

EN1177-HIC Impact Attenuation (Hemispherical Fall Missile) (Critical Drop Height (m))-EN1177-Impact Damping The determination of the critical drop height method for playgrounds is generally used to evaluate playground surfaces in the United States. Similar to the method used. Internationally, it is the main method of both artificial turf and playground surface finishing. This device calculates the Head Injury Criteria (HIC). It is used to measure the possibility of head trauma due to surface impact. The device is a hemispherical 10-pound "missile" equipped with a 3-axis accelerometer. The hemisphere is dropped from different heights in (4) to determine the height at which the HIC is 1000. This height is called the critical drop height. It is recommended that the critical drop height value be greater than 1.3 meters.

Rotational Resistance-EN15301 (Newton Meter (n))-Rotating Resistance measures the interaction between the cleat sole and the surface related to the ability of the player to change direction. Higher values may be associated with surfaces that resist rotation of the foot when the player is turning and increase the likelihood of lower limb injuries. The STC guidelines recommend that the result be 30n-45n.

Vertical Ball Rebound-EN12235 (meter (m))-Measure how high the ball bounces when dropped vertically onto an artificial turf field. The ball is released from 2m and the height of the rebound from the surface is calculated. The ball is first calibrated to 1.35 m on a flat concrete surface. STC is. From 60. We recommend up to 85m.

Tables I-III below show the results of tests performed indoors for each of the particles compared in each artificial turf system.

The results of the tests shown in Tables I-III are based on the use of PVC filling pellets and granules of various sizes and irregular shapes (such as asymmetrical shapes) that are dispersed as fillings in artificial turf installations. Embodiments of the invention show that the artificial turf is provided with improved performance characteristics over conventional artificial turf installations.

Various embodiments of the present invention have been described. However, it will be clear that various modifications and modifications can be made and additional embodiments can be implemented without departing from the broader scope of the exemplary embodiments set forth in the claims. This specification should be viewed in an exemplary sense rather than in a limiting sense.

Claims (20)

Includes synthetic filaments or fibers that simulate grass adhered to the backing and a filler having a layer dispersed as a layer of non-uniform polyvinyl chloride-based particles between the filaments or fibers. Artificial turf, wherein the particles include an asymmetrical shape and different sizes. The artificial turf according to claim 1, wherein the particles are at least one of pellets and granules. The artificial turf according to claim 2, wherein the particles contain at least three different sizes. The artificial turf according to claim 3, wherein at least some of the particles contain an elliptical shape. The artificial turf according to claim 3, wherein at least some of the particles contain an egg shape. The artificial turf according to claim 3, wherein at least some of the particles contain an obovate shape. The artificial turf according to claim 3, wherein at least some of the particles contain a biconvex shape. The artificial turf according to claim 3, wherein at least some of the particles contain an asymmetrically oval shape. The artificial turf according to claim 3, wherein at least some of the particles contain a tear-shaped shape (lacrymiform shape). The artificial turf according to claim 3, wherein the particles include a plurality of different shapes selected from the group consisting of an elliptical shape, an egg shape, an obovate shape, a biconvex shape, an asymmetric egg shape, and a teardrop shape. The artificial turf according to claim 2, wherein at least some of the particles have an elliptical shape. The artificial turf according to claim 2, wherein at least some of the particles contain an egg shape. The artificial turf according to claim 2, wherein at least some of the particles contain an obovate shape. The artificial turf according to claim 2, wherein at least some of the particles include a biconvex shape. The artificial turf according to claim 2, wherein at least some of the particles contain an asymmetric egg shape. The artificial turf according to claim 2, wherein at least some of the particles contain a teardrop shape. The artificial turf according to claim 2, wherein the particles include a plurality of different shapes selected from the group consisting of an elliptical shape, an egg shape, an obovate shape, a biconvex shape, an asymmetric egg shape, and a teardrop shape. The artificial turf according to claim 1, wherein the particles include a plurality of different shapes selected from the group consisting of an elliptical shape, an egg shape, an obovate shape, a biconvex shape, an asymmetric egg shape, and a teardrop shape. 18. The artificial turf of claim 18, further comprising a layer containing sand beneath a layer of polyvinyl chloride-based particles. The artificial turf of claim 1, further comprising a layer containing sand beneath a layer of polyvinyl chloride-based particles.

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