UA75599C2 - Synthetic grass-plot with springy granulated upper surface layer - Google Patents

Abstract

A synthetic grass assembly for installation on a supporting substrate comprising a pile fabric with a flexible sheet backing (1) and a plurality of upstanding synthetic ribbons (2) of a selected length, the ribbons (2) extending upwardly from an upper surface of the backing (1), an infill layer (3) of particulate material disposed interstitially between the upstanding ribbons (2) upon the upper surface of the backing (1) with a depth less than the length of the ribbons, the particulate material selected from the group consisting of hard and resilient granules. The infill layer (3) comprises a bottom course (5) of intermixed hard and resilientgranules of substantially identical size distribution, disposed upon the top surface of the backing (1), and a top course (6) substantially exclusively of resilient granules disposed upon the bottom course (5), an upper portion of the synthetic ribbons (2) extends upwardly from a top surface of the top course (6).

Description

Description of the invention

The invention relates to a synthetic lawn consisting of grass-like narrow strips forming a grid 2 that binds an infill of particles, this infill having a bottom layer of sand and rubber granules of the same size and an upper layer of only rubber granules.

Natural grass lawns in sports playing arenas and landscaped areas are expensive to maintain, natural grass does not grow well inside shaded indoor stadiums, and constant heavy traffic on it wears out certain areas on the surface of natural grass. Due to intensive use, the surface of natural lawns is destroyed, and the appearance of exposed soil leads to the unwanted accumulation of water and mud. Therefore, in order to reduce the maintenance costs of intensively operated sports playing arenas, to make the surfaces of these arenas more uniform and to increase the stability of the grass surface, especially in structures related to professional sports, synthetic turfs have been developed.

Synthetic turf is created using a carpet-like pile fabric that has a flexible base 12 laid on a compacted, permeable subsoil, such as crushed stone or other fixed base material. The pile fabric consists of rows of vertically standing synthetic narrow strips, which are grass stalks rising up from the upper surface of the base.

Of particular interest for this invention are various compositions of granular resilient filling, which is placed between standing narrow strips on the upper surface of the base to simulate the presence of soil. In the earliest known systems, it was practiced to use some solid particles, such as sand or crushed slag particles, together with elastic particles, such as crushed rubber particles, or together with a base of foamed material to provide elasticity. A distinctive feature of this invention is the optimal selection of particle sizes, their shape, composition, and their placement in stacked layers or strata. with

U.S. Patent No. 4,337,283 of the inventor Haas, Jr.) to obtain a more elastic and less abrasive (39 infill, a homogeneous infill mixture is proposed to simulate soil, which is made of fine solid particles of sand mixed with elastic particles in a ratio of 2595 to 95956 per by volume. Such elastic granular material can consist of mixtures of granular rubber particles, cork polymer balls, foam rubber particles, vermiculite, etc.

According to the US patent No. 4,396,653 of the inventor Tomarin a non-homogeneous filling is proposed, which consists of Ge"! rubber particles forming the base layer and sand particles forming the top layer. Rubber particles give the surface internal elasticity. The sand layer is exposed and forms a retaining cover layer for the underlying layer of rubber particles. yu

The use of granular filling in the form of a homogeneous mixture, as in the Haas system, where solid particles of sand and elastic rubber particles are mixed together and evenly mixed throughout the thickness of the filling, has several disadvantages. For example, synthetic turf infill may consist of a mixture of 6090 by weight sand and 4095 particles of granulated rubber, which are evenly mixed and placed between standing strips of synthetic grass to a depth of 1 to 3 inches (2.54 to 7.62 cm). "

A large percentage of sand offers an advantage in terms of reducing the cost of such systems, since rubber C particles are relatively expensive compared to sand. The sand particles also provide a better level of drainage, which is necessary, for example, in the case when the synthetic turf is not in an indoor stadium. The rubber particles tend to impede the free passage of water, while the capillary action of the sand particles pulls the surface moisture down, due to the difference in the surface tension characteristics of rubber and quartz sand.

However, in both Haas and Tomarin systems, the abrasive sand particles present in the upper surface layer of the infill create problems in games such as American football and rugby, traditional football, field hockey, baseball, as players often fall or are knocked off their feet by 4! playing field surface. When using turf for these purposes, there is a need to protect players from abrasive skin injuries caused by hard granules of infill sand, and from spraying sand that gets into players' eyes, ears, and mouths.

Te) 20 Usually the filling is a mixture of sand and rubber particles. When the ball hits the surface or the athlete steps on it, the rubber particles are compressed and straightened. In the case of ordinary soil, soil and humus particles provide some natural elasticity, but recovery from deformation is slower due to moisture, small particle size and relatively low natural elasticity. In the case of synthetic fillings, the particles are relatively dry and do not stick together. Rubber particles, like a spring, have a quick elastic 52 recovery after deformation, which leads to the upward thrust of neighboring sand and rubber particles under the action of force.

GF) Synthetic infill is constantly exposed to water jets and impact forces that try to dislodge or separate the particles, i.e. the effects of such factors as rain, flooding, bouncing balls, vibration and the impact of the feet and bodies of players in contact with the upper filling surface. A high amount of sand in the top layer will cause sand particles to be sprayed when the ball or player hits the top 60 infill surface. As the soccer ball rolls on the infill surface, if any sand particles are present on the top surface, they are lifted by the ball due to the suction force caused by the air flowing around the rapidly rotating ball and by electrostatic attraction. As a result, small particles of sand from the top surface of the infill rise and spray in the form of a "rooster's tail" behind the rolling ball. Over time, sand will become visible on the surface of the playing field in areas where sand is constantly sprayed or hit by a 62 ball. It seems undesirable that light sand should be visible on the surface of synthetic turf, especially when clouds of sand are visible during such impacts. In addition, exposed sand granules pose a severe abrasive threat to the skin when players fall or slide on the top surface, and can cause eye, ear, nose, and mouth irritation if sprayed, inhaled, or swallowed.

A further disadvantage of known infills is that abrasive sand particles remain on the top surface of the synthetic turf, and players who come into contact with the sand particles on this surface experience abrasive skin damage. Over time, due to moving water, vibration and impact, the fine sand particles will try to sink down to the bottom of the fill layer, while the larger and more abrasive sand particles will rise to the top surface. The fine sand particles slide down into the voids between the larger particles under the 7/0 action of vibration, water and gravity. Smaller particles collect at the bottom of the granular fill layer and tend to compact. Larger sand particles remain on the surface of the granular layer, and these large particles, compared to smaller particles, are capable of causing severe abrasive damage to human skin.

As a result, the abrasive nature of the synthetic system increases over time, and it may happen that certain /5 Areas of the playing surface exposed to heavy traffic become more abrasive than other areas.

Solid particles and elastic particles used in known solutions have angular surfaces. However, it was found that angular particles tend to compact more strongly than spherical or rounded particles because the friction between the sharp, angular surfaces is greater. In addition, in the case of using a wide range of particle sizes, smaller particles fill the gaps between larger ones and thereby increase the degree of compaction.

If pulverized rubber or, more commonly, ground rubber is used, the surfaces of the rubber particles are irregularly shaped, often with fibrous protrusions that trap air and hold water by surface tension. When the infill rains or becomes flooded, the air trapped in the rubber particles of low weight causes the rubber particles to float. This is undesirable, because together with the surface flow of water, the drainage can be washed away, and in the filling mixture, the rubber that floats is separated from the heavier sand, which leads to delamination of particles, compaction of the sand and loss of elasticity of the filling.

When using sand for construction purposes, for example, in road construction or for the preparation of i) concrete mixtures, it is highly desirable to have a wide range of particle sizes, in particular, because the mixing of small and large particles will lead to the filling of the spaces between the large particles with small particles, to the strengthening contact between them and better sealing, and therefore to an increased ability to withstand the load. In construction, when sand or granular aggregates are used, vibratory compactors are used, and the moisture content is controlled in order to obtain maximum compaction and density Me of the construction mortar. yu

However, when sand is used as a resilient gap-fill component in synthetic turf, excessive compaction is highly undesirable. The high degree of sand compaction and the introduction of dirt and dust from the air into the infill lead to undesirable changes in the elasticity of the infill over time, which is a result of operation, and the level of which can vary significantly along the surface of the synthetic turf, from areas with intensive use to areas with little use. exploitation Therefore, uniform and stable elasticity of the infill, elimination of its current repairs and predictable operational properties are more desirable than its ability to withstand heavy loads. "

Usually, the solution to the problem of compaction and separation of infill particles consists in periodic treatment with synthetic lawn brushes. Brushing helps to break up compacted material and mix the upper layer. surface, restoring as much as possible the original composition of the filling mixture. Brushing increases the cost of technical maintenance of the lawn, exposes the synthetic strips to significant wear and tear, and is at best a temporary solution, as the regular infill eventually compacts again and requires regular brushing. - And it also turned out that the appropriate selection of the distance between the rows of strips that form the lawn is also problematic.

Quite often, the main complaint of professional athletes is that the traction elements on boots do not adequately release from tightly packed, sodden, tightly woven or bonded surfaces of synthetic sports turf, resulting in knee and ankle injuries. Older artificial turf surfaces were manufactured in much the same way as gym carpet surfaces, with very closely spaced standing fibers running from a woven base that has a resilient underlay. These fiber

Ge surfaces were designed to remain upright and avoid being trampled when stepped on. Therefore, for this purpose, the fibers were located too close to each other. However, the traction elements on the athletes' shoes often did not release properly, especially when the foot rolled on the surface, and this led to injuries to the knees and ankles.

On the other hand, when clean sand acts as a surface, for example, in arenas for riders, such

F) the surface is relatively unstable, and sand particles are easily moved. To stabilize such surfaces, a mixture of sand with a relatively small weight percentage of straight synthetic fibers, randomly distributed and cross-linked in a freely moving mesh is proposed (US patent No. 4,819,933 of the inventor Armond (Ribgezap and Ltd.)). Fibers serve to distribute concentrated loads, hold sand together under the weight of horse hooves, athlete's feet, wheeled vehicles or equipment. || US patent No. 5,326,192 of the inventor Frid (Zupipeiis Ipdivigiev, ps.) also proposes a method of improving the appearance and operational properties of the lawn surface by inserting individual bundles of synthetic fibers into the soil surface. 65 The disadvantages of the above-mentioned granular infill systems in combination with standing synthetic grass-like strips are largely determined by how the granular artificial surface is created, which, in order to better imitate the natural pound, roots and grass embedded in it, is interwoven with standing fibers extending from the fabric base. When the traction elements on the athletes' shoes are pressed into the granular fill, the loose particles shift and move somewhat like natural soil. At the same time, standing synthetic turf strips grip loose particles and traction elements to reduce or deflect slippage. Without synthetic strips, it is very difficult to force loose particles to flow like dry sand over the surface of a natural seashore, and at the same time, a dense mat of tangled fibers firmly holds the traction elements, preventing their release and possibly causing bodily harm. 70 Therefore, to provide the desired playing field surface, the combined structure consisting of standing narrow strips and loose particle infill must be balanced or optimized. When the strips are tightly packed together, the traction elements cannot be released properly, but when these strips are placed far enough from each other, the required adhesion force and stability cannot be achieved.

Due to the high cost of artificial turf structures and the risk of bodily injury to highly professional and highly paid athletes, it is necessary to have predictable and reproducible characteristics of this artificial turf.

Synthetic turf surfaces were also created with infill, which mainly consists only of rubber.

The rubber particles are relatively light and the crushed particles have fibrous surfaces that trap air bubbles.

As a result, during flooding in some known devices, rubber particles floated to the surface of the water, washing away the surface of the synthetic lawn. The rubber particles are washed out or displaced, causing some areas of synthetic turf to have less infill thickness. A lack of uniform infill thickness and resilience along the surface can result in bodily injury and liability for sports field owners.

Despite the fact that several different rubber-sand filling compositions and different fibrous structures are known, several significant disadvantages, as indicated above, remain. with

The subject of this invention is to create a filling that will retain its properties during operation without significant delamination or compaction of the filling and with less requirements for periodic i) surface treatment with brushes.

Another purpose of this invention is to increase the elasticity and reduce the abrasiveness of the known granular fillings, which are used to fill the gaps between the strips of synthetic turf, and at the same time | b z to enable the ground-engaging elements on the athletes' shoes to be released properly without serious risk for the athlete to receive bodily injuries. b"

A further object of the present invention is to eliminate the scattering of sand particles and the unwanted appearance of sand on the backfill surface.

The invention proposes a new construction of synthetic turf that is installed on a supporting subsoil and provides a surface that combines the look and feel of natural turf with the wear resistance of synthetic turf. Although a sports playing field is described by way of example, the invention is equally applicable to any area suitable for turf, such as high-traffic landscaped areas, highway and freeway medians, patios, or grass playing fields. in golf and riding arena surfaces. "

The turf construction consists of a pile fabric with a flexible base plate and rows of vertical synthetic strips that represent grass stalks rising from the top surface of the base. In the spaces between the strips standing on the upper surface of the base, a unique layer of filling is laid;" from two layers of material in the form of particles located on top of each other, and the depth of the layer is less than the length of the strips.

The strips are bundled into a water-permeable fabric base, and they have longitudinal cuts made with -I gaps according to a predetermined shape. When the filling is laid, the strips are lightly brushed to return them to their upright position from their initial shriveled state, which is the result of being pressed against the strips when the tufted fabric is twisted for transport and storage after manufacture. c Strips can be on the order of one inch (25.4 mm) wide with several rows of cuts across the width. Light brushing reveals the lower part of the strips and opens the cuts by stretching, forming side-tied strands that are placed in the form of a lattice structure and which bind the surrounding filling particles. As

As soon as the entire filling is laid, the upper part of the strips, which extends above the layer of filling, is energetically processed with brushes. Under the action of the brushes, the strips are split longitudinally along the cuts into several separate free-standing strands of a smaller width, resembling grass stems. 5B The invention recognizes that granular filling is a dynamic system of hard and elastic particles of different sizes and with different physical properties, which are in constant motion under the influence of impacts and

F) vibrations during the game, technical maintenance of the surface and during atmospheric precipitation. Such dynamic activity is used in the invention in several ways.

The upper surface is kept virtually free of sand, for which a top layer of pure boron rubber particles of relatively large size is used, mostly preferably larger than the size of the particles in the lower layer. Any smaller sand particles that, due to the displacement caused by the earth-engaging elements, migrate up to the upper surface, will later be able to pass, under the action of water, vibration or gravity, through the voids between the larger particles of the upper surface, down back to the lower layer. Below the top layer of pure rubber, there is a bottom layer of a mixture of sand and rubber, which serves to provide additional elasticity, 65 moisture removal and as ballast to stabilize the fabric base.

The shape of the particles is essentially spherical in order to reduce contact friction between the particles, improve drainage and prevent compaction. The spherical shape of the particles reduces the resistance to their movement, and therefore reduces the degree of compaction compared to ordinary angular particles. In the values of the sphericity coefficient known to specialists, the shape of the particles in a broad sense is in the range from 0.5 to 0.99, but preferably in the range from 0.6 to 0.9, that is, the particles are well rounded or essentially spherical.

In the bottom layer, the particle size distributions for hard sand particles and elastic rubber particles are chosen to be essentially identical, and mainly for the surfaces of sports halls and playgrounds, the particle sizes are limited to the interval 14-30 mesh (1.41mm-0.59mm). When using synthetic turf surfaces for other purposes, particle sizes can vary from 0.5 inch (12.7 mm) to 50 mesh (0.297 mm). 7/0 Horseman pads can use larger particles, up to 0.25 inch (6.35mm), but these larger granules are very abrasive when in contact with human skin. Particles smaller than 50 mesh (0.297mm) contribute to the formation of dust and can lead to undesirable compaction, reduced water infiltration and delamination of particles. Soil particles of this size range that occur in nature are classified as particles of medium-grained sand, coarse-grained sand, and fine gravel.

By the concept of "essentially identical" size distributions it is meant that when the bottom layer of the fill is analyzed with the help of sieve analysis known in soil science laboratories, and the results are graphically presented on a standard semi-logarithmic plot for sieve analysis (where along the y-axis 0-100 weight percent of particles of those sizes that passed through the sieve, or percent smaller, and along the x-axis in a logarithmic scale plotting sieve numbers/particle sizes), the line for hard 2o particles and the line for elastic particles almost perfectly overlap each other. Therefore, hard and elastic particles have essentially the same size and in fact the same size distribution.

Standard sieve analysis charts are by their very nature imprecise "hasty" measurements because natural soils vary markedly, for example, along the surface of a construction site. Graphs of sieve analysis generally do not show the largest 1095 and smallest 1095 sizes of s and ge particles, because from the point of view of statistics these extreme values are considered unimportant due to natural deviations in the sizes of soil particles. Therefore, when studying soil particles by sieve analysis, i) only average 80905 particles are usually considered.

When applying this technique to the invention, numerically or scientifically, it was determined that the particle size distributions are essentially identical or very well ordered where 80% by weight of the hard and elastic granules of the bottom layer are size-distributed in the interval that overlaps the numerical difference of 40 mesh. Since the sand and rubber can optionally be graded according to any technical requirement, even a smaller numerical difference, such as 20 mesh, is preferred in order to produce a more uniform infill. For example, glass balls produced as perfectly spherical should have a numerical difference close to zero. However, since sand is a natural material formed by the erosion of rocks, its particle size distribution and sphericity vary significantly. uh-

A numerical difference of 20 mesh may be the result of a particle size distribution, for example between 10 mesh (2.00 mm) and 30 mesh (0.59 mm) for riding arena surfaces, or between 20 mesh (0.84 mm) and 40 mesh (0 ,42 mm) for surfaces of sports playing fields.

In practice, the cheapest material in the form of particles is usually sand, which is found in naturally separated sediments and/or mechanically sorted to meet various common construction needs, for example, for use in concrete mixes and in the construction of road surfaces. Requirements for sand that has

And to be used to create an artificial lawn, they are relatively low, and therefore if the project requires the distribution of specially segregated or sorted sand by size, then the cost of such material will rise slightly.

Anywhere when deciding which special materials should be used, an advantage

Any suitable sand available near the construction site can be used. When purchasing elastic -I particles, it is relatively easy to condition their size distribution so that it is within the above intervals and overlaps with the measured size distribution of sand particles. Elastic particles must be manufactured, ground and brought from the place of production, regardless of where the place of construction is located. c The marginal cost of producing elastic particles with a size distribution that matches the distribution of the sand particles is relatively low compared to the alternative sorting of the sand particles so that their size distribution corresponds to the distribution of the elastic particles.

Ge) In the production of elastic particles, the size distribution of which corresponds to the sand available at the construction site, the bottom layer of filling, consisting of a mixture of sand and rubber particles with the same size distribution, will, as a result, receive an advantage in the form of significantly reduced sedimentation and separation particles in the used mixture.

In contrast, in the known mixtures, the elastic particles are generally much larger than the existing sorted ones

F) sand. As a result, under the combined influence of gravity, vibration, rain and water seeping down, lighter and larger elastic particles migrate upwards, and heavier and smaller solid sand particles migrate downwards. Stratification of particles of different sizes in the layers of known mixed fillings leads to the loss of optimal sealing and unequal adhesion force.

The inventor has found that separation of solid and elastic particles in a mixed bottom layer can be prevented or greatly reduced by (1) selecting solid and elastic particles with identical or essentially identical size distributions, (2) selecting a relatively narrow particle size range, and (3) by choosing a generally spherical shape, both for solid and for elastic particles. A minimum deviation in particle size of 65 prevents compaction because when all particles are essentially the same size, the relatively small particles are absent and do not fill the spaces between the larger particles. The spherical shape of the particles reduces the resistance to their mutual movement and reduces the tendency for neighboring particles to stick together. Fibrous synthetic grass-like strips on the upper surface help to retain the relatively large upper rubber particles in the flexible structure of the loose mesh. An unfastened criss-cross grid of strips with imparted fiber also allows

Embossed rubber particles return to the underlying upper rubber layer when the foot moves over these particles and synthetic strips. The combination of a pure rubber top layer and a grid of strips with added fiber has the look and feel of a natural turf surface.

Synthetic strips between the fabric base and the upper layer provide a certain degree of resistance to the movement of particles in the mixed lower layer due to the formation of an open mesh or 7/0 lattice structure of vertically oriented strands that are laterally connected to each other. The sand-rubber bottom layer provides a strong and resilient base for the relatively thin rubber top layer. The sand content in the mixed layer provides, in particular, the necessary weight for ballast and for better drainage, thanks to the capillary action of the sand.

The relatively thin upper layer, which is in direct contact with the athlete's body, in the place where physical contact occurs, has high elasticity, as a result of which, due to the exclusive use of /5 rubber, there is a slight abrasive injury to the skin. The sand content of the mixed sub-layer provides a ballast weight to hold the lawn in place, as well as to quickly drain water from the surface. Drainage is particularly necessary where there is a risk of freezing, and in cold climates it may be necessary to choose a coarser mix for better drainage. The elastic particles in the mixed layer also provide subsurface elasticity in addition to the upper surface elasticity provided by the upper layer.

Choosing hard and resilient particles with essentially the same size distribution actually reduces compaction and reduces lawn maintenance requirements. Due to the choice of particle sizes, the top layer of pure rubber will always remain essentially free of sand. Sand can be forced from the mixed bottom layer to the surface of the top layer by shaking caused by contact with the ground-engaging elements of the player during a game or practice, in much the same way that normal soil is disturbed by such an action. However, the sizes of the sand particles are chosen to be smaller than the sizes of the elastic particles in the upper layer. Therefore, the washing away of displaced sand particles by rainwater, which washes the upper elastic layer, or i) vibration and shaking from the movement of the foot return smaller sand particles to the lower layer, from where they flew out.

The arrangement in two layers, with the upper layer of only rubber and the lower layer of a mixture of sand and rubber, creates an elastic surface at lower costs and with a lower thickness than in known methods, for example, those described |in Ge! from US patent Mo4,337,283 inventor Haas and US patent Mo4,396,653 inventor Tomarin)|. Known layers of filling from large and small particles have a tendency to compaction or to bond into a more solid and dense surface. The structure proposed in the invention retains its elasticity even when thin layers are used in it, because the upper layer consists of granules of pure rubber, and the mixed lower layer is not prone to separation or compaction. Thus, more predictable long-term resilience is created. at

Synthetic strips can be manufactured and inserted into a fabric base. Preference is given to strips with relatively short longitudinal cuts made at a distance from each other along the entire width of the strip. Next, after the infill is placed, the upper part of the synthetic strips is given a fiber in place, they are split or scraped in a vertical direction by passing a brush over the laid surface.

After manufacture, the strips have a longitudinally oriented structure, and therefore vigorous brushing of the upper surface contributes to the tearing or splitting of the strips into thinner grass-like strands, due to /7-Z) with the continuation of the slits in length and the formation of densely compressed separate strands resembling grass . . Where the strips are brushed and thereby split in place, the upper parts of the strips and? are frayed or split into fine grass-like strands, while their lower parts remain intact and simply stretched into an elaborate web, net, or trellis structure to a greater extent than

Then, when fibers were originally inserted into the base. A direct benefit of such lattice structure -I is the stabilization of the granular filling due to the mutual adhesion of particles between the fibrous grass-like strands and within the stretched, web-like fibrous structure. The lower web-like part stabilizes the infill, and the upper grass-like part makes it possible to enter the lawn and with the release of soil-binding elements, rain seepage and drainage, adds a slight surface elasticity, thanks to the bent grass-like strands, and captures large elastic particles of the upper layer into a grass-like mesh structure.

Ge) Fibering the strips in place also allows for a denser surface coverage with grass-like strands. Relatively wide strips with holes in the form of short cuts from the start can be spaced apart at a certain distance from each other to allow the granulation to be placed between the strips

Filling. When the infill is completely laid, brushing the widely spaced strips breaks them up into thinner, grass-like strands that fill the gaps between the strips and better cover the top surface (F, of the granular infill. The dense mesh of cross-woven fibrous strands contains large granules in the upper layer and in that at the same time allows soil-engaging elements to enter the lawn and allows water to pass through. Split strips at a lower cost provide a better visible surface with grass-like strands. In non-sports applications such as artificial landscaping or for decorative purposes , the fibers can be placed less densely, as a result of which, at a lower cost, we get a cover with the same appearance as conventional closely packed synthetic lawns.

Further details of the invention and its advantages will become apparent from the detailed description and illustrations that follow. 65 In order that the invention may be better understood, one of the preferred embodiments thereof is described below, by way of example, with reference to the accompanying illustrations, wherein:

Fig. 1 is a cross-section of a synthetic turf structure with stacked infill, showing the base, in the form of a flexible plate, with standing strips and an infill layer composed of an upper layer, in which there are relatively large elastic rubber granules, and a lower layer, which is a mixture smaller granules of hard sand and elastic rubber with identical particle size distribution;

Fig. 2 is a similar cross-section, showing the final configuration of grass-like strands, slightly bent, which is the result of vigorous surface treatment with brushes in order to further give fiber to the ends of the strips;

Fig. 3 - a side view of the synthetic strip in the manufactured state with a number of holes in the form of short longitudinal slits; 70 Fig. 4 - a side view of a synthetic strip, the lower end of which is twisted before being inserted into the fabric base, and the upper end is stretched to the sides in order to open the web-like structure of grass stems, which appears as a result of stretching to the sides and extending the slits in length;

Fig. 5 - a table, which graphically shows the distribution of particles by size, obtained as a result of a standard sieve analysis of filling layers; and

Figb - a table showing the image of particles as perceived by the eye, arranged according to the Krumbein sphericity scale.

With reference to Fig. 1, the invention relates to the construction of a synthetic lawn, which consists of a pile fabric with a filling layer of granular material and which is installed on a supporting subsoil, and thereby forms the surface of the playing field.

The pile fabric consists of a flexible base plate 1, which may include two or more layers of open woven fabric; one of them may be a mesh material with stable dimensions to prevent stretching during installation and operation. A large number of vertically standing synthetic strips 2 extend upward from the upper surface of the base 1. As shown in Fig. 1, the strips 2 come out in bundles from the base 1, are placed in rows at a distance of MU from each other and have a length of GI. The length "I" of the fibers is selected depending on the total depth (5 plus 6) of the filling and the desired elasticity of the finished structure of the synthetic lawn.

In the spaces between the standing strips 2 on the upper surface of the base 1, a layer C of filling made of material in the form of particles is laid. The particulate material may be selected from any number of commonly known solid granular materials such as: sand; solid construction aggregate; quartz sand; gravel; slag; b from granulated plastic; and polymer balls. Elastic granules can be selected from: cryogenically ground rubber; rubber; crust; polymer balls; synthetic foamed polymer; styrene; perlite; neoprene; crushed tires; b" and rubber based on a copolymer of ethylene, propylene and diene monomer. yu

The filling layer C is made in the form of an upper layer 6 and a lower mixed layer 5. The mixed lower layer 5 consists of mixed solid sand granules and elastic rubber granules. The mixture is selected based on the distribution of different sizes for hard granules and elastic granules by volume, which is essentially the same size range from 0.5 inch (12.7 mm) to 50 mesh (0.297 mm). The particle size range is limited primarily to avoid thin or fine particles that fill the spaces between larger particles and promote compaction. The preferred spacing is between 14 mesh (1.41mm) and 30 mesh (0.59mm).

Depending on the application, the range of particle sizes in the mixed layer can be limited to the ranges of 10-30 mesh (2.00-0.59mm), 15-30 mesh (1.3-0.59mm) or 20-40 mesh (0. 84-0.42 mm), which is selected in accordance with the design parameters. The shape of the hard and elastic granules is essentially spherical, and not angular, as in known solutions, in order to strengthen the obstacles to compaction and settling. ;" The graph in Fig. 5 shows the results of the granulometric analysis carried out using standard sieves, where along the vertical axis in a linear scale the "weight percentage of particles that passed through the BITO" or alternatively "percentage of smaller" is displayed, and along the horizontal axis in a logarithmic scale - And particle size or sieve number. The line shown in Fig.5 for example shows a relatively homogeneous mixture of particles with a narrow range of their sizes. Ideally, the line in Fig. 5 for the size distribution of sand particles 1 and the line for the size distribution of rubber particles are identical and should overlap each other. As an example, the above interval of 10-30 mesh (2.00-0.59mm) is shown on the graph as a shaded area within which any

The line will meet the requirements of this particle size limit. ik The upper layer b consists exclusively of elastic rubber granules. Up from the upper surface of the 8 upper

The upper part of the 7 synthetic strips 2 is spread over the layer 7. The resulting artificial turf surface can be used for various purposes, such as: playing sports fields, horse racing fields, sports fields, landscaped areas and recreation areas.

To apply the two-component layer, the brushes are passed over the base with a mixture of sand and rubber several times, to ensure that the strips inserted in the filling are in an upright position, and not hidden under (F, the filling), and to stretch the strips a little more to open the slots and creating a grid structure that stabilizes the infill and prevents excessive movement of its particles after the turf is installed.After the lower mixed infill layer is laid, a granular material of virtually pure rubber is placed as the top resilient layer.

Spreaders may be used to lay the bottom layer, after which the surface is brushed to raise the pile on the pile fabric and to place the strips 2 in a generally vertical position before laying the top layer. After the distribution of each layer, the surface must be treated with brushes and raise the strips to a vertical position, as shown in the illustrations. 65 In a variant that may have an advantage, after laying the upper layer 6, the upper part 7 of the synthetic strips 2 is additionally provided with fiber by vigorous passage of brushes over the surface. This operation splits the upper portions 7 and distributes the strands evenly over the top surface 8. The strips 2 are made quite wide, on the order of one inch (25.4 mm), and the in-situ brushing operation further splits these strips, splitting the slits lengthwise and forming as shown , thinner and narrower grass-like strands. The upper ends of the strips 2 are brushed more vigorously to achieve the following advantages over known methods. A covering of fiber tops 7 interlocks the ends of the strips into a loose mesh that more realistically mimics the appearance of natural turf. The fiber ends add a slight springiness as they are slightly raised or fluffed up and more closely mimic the springiness of natural grass as the ball bounces on the finished surface during play. In addition, the inclined ends make the rubber crumbs of the upper 7/0 layer 6 inaccessible to the eye, hold these crumbs in place and allow the movement of the knocked-out crumbs back and forth between the upper layer 6 and the upper wall of fiber strips 2. By splitting the ends of the strips 2 or making them fibrous, the surface tension is reduced and water more easily seeps through the upper surface and drains through the lower layer 5.

Strips 2 have an upper structure consisting of many grass-like strands that have been given a /5 fiber in situ and a stretched web-like lower structure that has remained largely in its original state but has been mechanically stretched into a web-like lattice by interaction with filling during its stacking.

The strips can be selected from such fibrous materials as polypropylene, polyethylene, nylon and plastic.

A mix of wide and narrow fiber strands creates a more natural look and makes the ball roll more predictably, depending on the resistance the fibers exert on the ball during play. Changes in the width of the strips and the density of the grass will also change the rolling characteristics of the ball.

The strips, when initially inserted into the fabric base, can be in the range of 1-3 inches (25.4-76.2mm) in width, and when fiberized, the width of the individual grass-like strands can be in the range of 1mm to 15 mm (approximately 1/8 to 1/2 inch). Expressed in industry terms, the webbing range spans from 800 to 5,000 denier, and the strip and web thickness range typically spans between 45 and 200 microns (M).

From experiment and experience, it was found that the size and shape of solid granules and elastic granules significantly i) affect the operational properties of the lawn. It also turned out that the operational properties of the synthetic lawn structure can be strongly influenced by the distance between the strips and the variation in the filling depth.

Solid and elastic particle sizes should be between 0.5 inch (12.7 mm) and 50 mesh Ge! zo (0.297 mm) according to the US standard, however, to avoid the risk of compaction, a narrower interval of 14-30 mesh (1.41-0.59 mm) is preferable. Hard granules larger than 14 mesh (1.41 mm) may be perceived by users as somewhat abrasive when in direct contact with the Me game surface. However, since the fibers above the upper surface have a tendency to arc and protect the user from direct contact with the curved elastic mat of synthetic fibers, slightly larger particles can be used without feeling abrasive. at

Particles smaller than 50 mesh (0.297 mm) will interfere with water infiltration and adversely affect the drainage properties of the C fill layer in relatively humid climates. In dry climates, it may be desirable to use smaller particles to maintain optimal moisture content, in order to maintain optimal levels of compaction and elasticity. When, due to the nature of the sports competition, skin contact with the surface and possible abrasion damage can be expected, larger elastic particles (eg, 14 mesh (1.41 mm)) can be used. The sand is preferably washed and sorted to remove all fine particles smaller than 50 mesh (0.297 mm).

The natural tendency of large, relatively light rubber particles to migrate to the surface and the additional tendency;" smaller and heavier sand particles migrate to the bottom of the C layer. Filling decreases when using particles of the same size. The migration of particles is also reduced due to the interaction with the web-like structure of the binthetic strips and due to the use of spherical particles. Due to the selection of virtually identical particle sizes and the creation of obstacles to their movement by a web-like structure of strips that are in contact with the lower filling layer, this layer retains the character of its original mixture consisting of sand and elastic o particles of the same size. These characteristics of the filling prevent its compaction and contribute to the maintenance of its predictable uniform elasticity.

When the upper elastic layer 6 is made of pure rubber, the elasticity is provided by the contact surface, where the feeling of elasticity is really needed. The rubber particles in the upper layer of the filling are mostly larger than

Ge) in size than the particles of sand and elastic material in the lower layer 5. The larger size of the particles of the upper layer allows the smaller particles of the lower layer to fall back down through the gaps between the large particles, as a result of which the compositions of these layers in terms of particle sizes remain dissimilar. The elasticity of the final layer of filling can be precisely adjusted by checking the elasticity on the surface and gradually distributing the rubber particles in order to maximally increase the thickness of the upper layer 6 and finally reach

F) desired elasticity of this layer. ka Synthetic strips are placed mainly in rows separately from each other at the minimum selected distance "MU". Depending on the stability desired and the degree of freedom required for the ground engagement elements to rotate during various sports, the "MU" distance can vary between 2.25 inches (57.15 Ω) and 0.625 inches (15.875 mm) or less. A smaller distance provides a stronger retention of the filling, and a larger distance allows the soil-engaging elements pressed into the lawn to rotate more easily.

The depth of the C infill relative to the "I" length of the synthetic strips can vary from 9095 to 4095, but for most applications the preferred range is 8595 to 5595 or 8095 to 7095. For example, 65 When the length of the Y strips is 2 inches (50.8mm) , then the padding depth of 7595 will be 1.5 inches (2.0 x 0.75-1.5) (38.1mm), with the remaining 0.5 inches (12.7mm) of the strip length extending above the top surface of the padding.

While it is the inventor's intention that the foregoing description and accompanying illustrations relate to a particular preferred embodiment of the invention, it is to be understood that in a broader sense the invention encompasses the mechanical and functional equivalents of the described and illustrated component parts thereof.

Claims (21)

Formula of the invention 70 1. The structure of synthetic lawn, which is installed on a supporting base and consists of: a pile fabric with a flexible base plate and a large number of vertically standing synthetic strips of the selected length, and the strips extend upwards from the upper surface of the base; a filling layer of material in the form of particles, which is placed in the spaces between the standing strips on the upper surface of the base and which has a depth less than the length of the strips, and the material in the form of particles is selected from the group which includes: hard and elastic granules; and the filling layer contains: the lower layer, which consists of mixed hard and elastic granules with essentially the same size distribution and which is laid on the upper surface of the base; and an upper layer which consists exclusively of elastic granules and which is laid on the lower layer, with the upper part of the synthetic strips extending upwards from the upper surface of the upper layer. 2. The construction according to claim 1, in which the elastic granules located in the upper layer are larger than the elastic granules of the lower layer. C. The structure according to claim 1 or claim 2, in which the hard granules and the elastic granules located in the lower layer have a shape defined by the interval from 0.5 to 0.99 on the Krumbein sphericity scale. 4. The construction according to p. C, in which the hard granules and elastic granules located in the lower layer are covered by an interval from 0.6 to 0.9 on the Krumbein scale. 5. The structure according to any of claims 1 - 4, in which the elastic granules are selected from the group that includes: (o) cryogenically ground rubber; rubber; cork; polymer balls; synthetic foam polymer; styrene; perlite; neoprene; and rubber based on a copolymer of ethylene, propylene and diene monomer. 6. The structure according to any of claims 1 - 5, in which solid granules are selected from the group that includes: sand; o z solid construction aggregate; quartz sand; gravel; slag; granulated plastic; and polymer balls. 7. A structure according to any one of claims 1-b, in which the particulate material comprising the infill layer b" contains granules with a maximum nominal diameter in the range of 0.5 inches (12.7 mm) and 50 mesh (0.297 mm). 8. The construction according to claim 7, in which 80 percent by weight of solid granules and elastic granules of the lower layer is) distributed by particle size in an interval that overlaps the numerical difference of 40 mesh. chn 9. The construction according to claim 8, in which 80 weight percent of the hard granules and elastic granules of the lower layer are distributed by particle size in an interval that overlaps the numerical difference of 20 mesh. 10. A synthetic lawn structure, which is installed on a supporting base and consists of: a pile fabric with a flexible base plate and a large number of vertically standing synthetic strips « 20 of selected length, with the strips extending upwards from the upper surface of the base; with an infill layer of particulate material interspersed between the standing strips on the upper surface of the base and having a depth less than the length of the strips, wherein the particulate material is selected from the group consisting of: solid and elastic granules; where synthetic strips: longitudinally cut with gaps between the cuts according to a predetermined shape; - and the upper part of the strips extends above the filling layer and is longitudinally split into separate free-standing strands of a given width to represent grass stalks; and o moreover, the lower part of the strips has the mentioned sections open due to expansion and forms strands connected from the sides of the slabs, which are placed in the form of a lattice structure and fasten the surrounding particles of the filling material. 11. The construction according to claim 1, in which the synthetic strips are placed in rows at a minimally selected distance from each other. Ge; 12. The construction of claim 11, wherein the maximum distance between the rows of synthetic strips inserted into the fabric backing is 2.25 inches (57.150 mm). 13. The construction of claim 12, wherein the maximum distance between the rows of synthetic strips inserted into the fabric backing is 1.0 inches (25.4 mm). 14. The construction of claim 13, wherein the maximum distance between the rows of synthetic strips inserted in the (F; fabric backing) is 0.625 inches (15.875 mm). GI 15. The construction according to claim 1, in which the depth of the filling layer is in the range from 90 95 to 40 96 of the length of the synthetic strips. in 16. The construction according to claim 15, in which the depth of the filling layer is in the range from 85 95 to 55 95 of the length of the synthetic strips. 17. The construction according to claim 16, in which the depth of the filling layer is in the range from 80 95 to 70 95 of the length of the synthetic strips. 18. The structure according to claim 1, in which the synthetic strips are fibrous materials selected from the group consisting of: polypropylene; polyethylene; nylon and plastic. 19. The construction according to claim 1, in which the upper part of the synthetic strips is provided with fiber in the form of separate strands with a width in the range from 1.0 to 15.0 mm. 20. The structure of claim 1, in which the synthetic strips have a thickness in the range of 45 to 200 microns. 21. A synthetic lawn structure, which is installed on a supporting base and consists of: a pile fabric with a flexible base plate and a large number of vertically standing synthetic strips of a selected length, with the strips extending upwards from the upper surface of the base; and the base and pile fabric are suitable for placing thereon a filling of material in the form of particles which fills the spaces between the strips to a certain part of their chosen length; where synthetic strips: 70 are longitudinally cut with gaps between the cuts according to a predetermined shape; and the upper part of the strips is longitudinally split into separate free-standing strands of a given width to represent grass stems; and moreover, the lower part of the strips has the mentioned cuts open due to expansion and forms strands bound from the sides, which are placed in the form of a lattice structure and adapted to bind the surrounding particles /5 of the filling material. c schi 6) (o) (o) IF) IF) and - - and? -i 1 1 se) iChe) ime) 60 b5