DE1946671A1 - Molded thermoplastic artificial lawn with attached underlay - Google Patents

Description

DR. BERG DIPL.-ING. STAPF 1Q / RR71

PATENT LAWYERS I JHOD / I

8 MUNICH 2, HILBLESTRASSE 2O

Dr. Berg Dipl.-Ing. Stapf, 8 Munich 2, HllblestraBe 20

Our sign 18 802 Thursday at 15, $ βΡ. 1969

Attorney File 18 802

Monsanto Company, St. Louis / USA

Molded thermoplastic artificial turf with attached underlay

Shaped synthetic turf, or synthetic grass, has recently been used in metropolitan areas where it is difficult to Growing grass has found a favorable intake in lieu of natural grass. In the same time pending German patent application P 1779059.9 is a synthetic turf "described that a is continuously molded thermoplastic material having a base portion with protrusions.

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The base also contains openings for water drainage, etc. In the French patent 1 314 933 describes another, but similar, shaped grass product which is available in square or Block shape is made with means for mutual connection. Furthermore, the US patent discloses 3,157,557 is yet another type of molded grass made from synthetic thermoplastic material is.

While synthetic thermoplastic molded grass products are relatively cheap and give a certain aesthetic impression, certain difficulties have arisen in their use. Because this synthetic grass products made from thermoplastic materials such as polyolefins they have the disadvantage of extremely poor dimensional stability, i.e. they tend to move when the temperature changes to expand or to wane. This is obviously undesirable when using the product as a lawn is used because the contraction leaves openings at the joints and the expansion leaves unsightly ones Can cause bumps.

According to this invention, these disadvantages are by a three-dimensional shaped grass-like product

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raised, which consists of a relatively flat thermoplastic base part with projections protruding from this, and are integral, i.e. firmly connected, components of the base part. The protrusions are shaped so that natural grass is simulated, and the base is provided with openings on its surface. According to the invention, a synthetic, porous fibrous sheet-like structure is located on the bottom side of the base part or an open-meshed metal grid connected to the base.

The base part and the projections located on it are made as an integral, firmly connected unit molded thermoplastic material. Because of its availability and its properties in use, polyethylene is used preferred, however, other materials such as polypropylene, nylon, polyester and the like can be used thermoplastic materials are used. Thermoplastic copolymers or mixed products are also included satisfactory. The base part, shaped as a unit, with the projections can be i.e. one plate at a time, or in a continuous process as mentioned in the copending process German patent application 1 779 059.9. Obviously, it becomes economic Consider a continuous process

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preferred. Regardless of the process by which the firmly bonded, shaped material is produced, but it is necessary that the base is provided with openings for water drainage.

In a continuous process of forming three-dimensional materials, as described in the patent application Ser.No. 650 986, openings in the base occur as a natural result of the process. The method delivers the projections as tufts, these tufts being formed by strips arranged in parallel are connected from thermoplastic material. Because the tufts do not adjoin each other, there are openings between the tufts. The protrusions extending from the base are substantial after molding directed vertically. To give the shaped material the appearance of natural grass, it is necessary to give it a special surface in order to make the tips of the protrusions quite like the natural grass in a random manner. This can be expedient by the action of a heated Roll press on the surface of the molded material, i.e. on the side from which the protrusions stand out, be achieved. If the thermoplastic material is hot enough, e.g. heat from the Retains the molding process, the roller press does not have to

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To be heated. This surface treatment gives the protrusions a permanent curl, thereby flattening them remain with peaks randomly distributed over the surface.

The main subject of this invention is education a base (reinforcement) material made of synthetic porous fibrous sheet material or from a open-mesh metal grid that is connected to the back of the base part, creating the above-mentioned Disadvantages are overcome. The use of the underlay serves to make the artificial turf dimensional To give stability.

Because the products of this invention find outdoor use, it is desirable that the backing have durability against weather. If the underlay chosen is a synthetic porous fibrous material, Suitable materials are polyolefins such as polypropylene, nylon, polyester, and other similar synthetic fiber-forming materials Materials. The synthetic fibrous material is molded to the bottom of the thermoplastic Q-round part connected in the form of a flat structure, that can be woven (fabric, fabric), but preferably not woven, i.e. a fiber fleece. That Underlay structure must be porous in order to allow water to run off

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to allow, and moreover, still be strong enough to form a permanent bond with the molded to form thermoplastic base part. Nonwovens are particularly suitable for this purpose.

The synthetic fibrous! Sheet-like structure is - preferably attached to the molded thermoplastic base, this being heated and the heated bearing in contact with the synthetic sheet brings and sufficient pressure, for example by squeezing rollers, used to the structure in the formed Embed object. Heat sealing is preferred because it does not introduce foreign materials and further no noticeable effect on the strength of either the molded thermoplastic base nor of the fibrous sheet. However, other methods of binding can be used if desired e.g. solvent or adhesive bonding, if the product is intended to be used for special purposes for which the stated disadvantages are neglected can be

In an additional embodiment of this invention, a thin synthetic cellular foam can be used the underside of the synthetic fabric can be attached. It has been found that when the synthetic

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table turf of the invention is intended to be used for a purpose in which sliding of the turf It is undesirable to use the foam as an additional back pad, e.g. as a door rugs Prevents sliding. Anyone can use synthetic for this purpose Foam can be used. · Polyurethane foam is particularly suitable, but other foams can be used as well such as polyvinyl chloride foams and the like can be used. The foam can be attached to the fibrous sheet-like structure with a Adhesive or some other suitable binding agent. He should be relatively thin because this is all there is for the property of not slipping is necessary.

Palis the chosen base is an open, porous metal grid aluminum is preferred, but other metals such as steel, stainless steel, iron, Lead and other similar metals can be used.

The metal mesh is preferably brought into contact with the thermoplastic base part by heating it the heated part of the base part with the grid and by applying pressure, e.g. via squeegee rollers, to embed the grid firmly in the base. This type of bond, i.e. hot welding, is preferred because it is not a foreign substance

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is introduced into the product. However, other bonding methods, e.g., adhesive bonding, can also be used for such Purposes are used in which the disadvantages can be neglected.

While the bonding of the metal mesh to the thermoplastic The base part serves to provide dimensional stability to the synthetic turf of this invention lend, it may still be desirable to attach an additional pad to the base. Since, for example, the grid consists of open meshes and the base part with openings for water drainage is provided, there is an opportunity for the weeds to grow through the openings. Such a weed growth can be delayed by attaching a fibrous plastic pad to the base, this fibrous pad to the base part in which the metal mesh is already embedded or to which it is connected, can be easily attached can. Because the metal grid is reticulated, a substantial area of thermoplastic material remains uncovered, to which the fibrous material can be bound. Although again other methods of binding It is preferred to use the synthetic porous fibrous backing with the base part through the holes in the open-meshed metal grille can be

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-welding. This binding can even be done simultaneously with the binding of the metal mesh. So can the metal grille brought into contact with the base part, with the synthetic fabric on the metal grid are heated, the base body and the whole assembly is passed through press rollers. Such bonding gives satisfactory results.

It is clear that, if desired, a thin synthetic foam can also be attached to the underside of the synthetic Fiber sheet, which is connected to the metal mesh, can be attached.

The accompanying drawings serve to explain the invention. 1 shows a section of the product the invention. As indicated, the molded product has thermoplastic stalks 1, preferably Are curled or curved to simulate natural grass. The stalks are preferably in clusters arranged, which have a base 2. The tufts of stalks form an integral, i.e. firm and substantial Part of the synthetic turf and are between parallel strips 3 of the same thermoplastic material arranged. The thermoplastic base part has a lower part connected to it

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layer 4, which is a metal mesh or a synthetic porpses fibrous sheet-like structure, namely a fabric or nonwoven fabric.

Fig. 2 shows a view of an additional embodiment of this invention, namely a foam material 5, .that with the underside of the metal grid or the porous sheet or a synthetic porous fibrous sheet that is connected to the base part through the open meshes of the metal grid is connected.

The following examples illustrate the invention.

example 1

This example illustrates a preferred method of making a synthetic molded lawn with a non-woven fabric, which is attached to the lower surface of the rabbit piece by means of a continuous process · The apparatus used to form the synthetic lawn of this example is fully described in the German patent application 1 * 779 059.9 and in Figs. 1, 15 and 16 of the aforementioned Registration shown *

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-Before the molded product removed from the designated device cools, a polyester fleece of the same width as the molded product and of light weight (28.4 to 56.8 g / 0.84 · m ² ) is placed on the flat Surface of the shaped piece of synthetic turf dispensed from a supply roll located above the apparatus.

The linear feed speed of the fiber sheet, hereinafter simply referred to as "fabric", is approximately equal to the peripheral speed of the roller and is controlled by its speed. While the fabric is being fed from the roller, it is stretched and running by a tensioning device then under a nip roll which embeds it into the curved surface of the patch of turf being formed. the Tension on the fabric is sufficient to stretch the fabric 1%, which is the size the thermoplastic material runs in after cooling. In this way the product can be without waves or bumps lie flat when used in outdoor temperatures. The press roll is against the surface of the product with a force of about 270 kg at the point of contact. At the same time the molded Heat is applied to the product before it comes into contact with the fabric. This is done to the polymer

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8AD

To keep the surface in a molten state, whereby it is possible for the polymer to flow into the interstices of the nonwoven fabric and to effect a complete bond between the nonwoven fabric and the shaped product. The heat supplied from the outside, which is supplied to the polymer immediately after the spraying, is preferably radiant heat. In this example, a 2000 watt infrared lamp placed approximately 2.5 to 5 cm above the forming roller is sufficient to keep the surface of the polymer in a molten state which is satisfactory for tissue bonding. During processing, the synthetic grass is cooled to give water of 21 ⁰ C in the interior of the drum 132 l / min charging thereto Once the molded lawn is cooled to about 80 ⁰ C at a rate of about, it is withdrawn from the drum, run through a pair of heated metal rollers for texturing and taken on a winding core to form large rolls of synthetic grass suitable for future handling and storage outdoor artificial grass capable of preventing weeds from growing on the ground beneath it and allowing water to run off, resulting in an aesthetically pleasing grass-like area that does not require the maintenance of the natural turf.

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Example 2

This example illustrates a method of making a synthetic molded rabbit piece which an associated anti-skid material on its underside having.

If desired, a synthetic grass-like molded product having a slip preventing To produce the underside, another material is first attached to the non-woven fabric. The following Steps and process conditions for molding the thermoplastic product and for bonding the fabric are the same as those in Example 1.

Illustrative is a 0.4 cm thick polyurethane foam sheet using conventional hot bonding techniques provided with a polyester fleece. The width of the plate and the fabric are approximately 90 cm. the Layered backing is then wound on a spool as a roll of fabric to cover with the formed patch of turf to be connected in a continuous process. The laminate is then with the polyester side directed against the molded product on the molten surface of the molded product and in connected in the same way as described in the previous example.

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The resulting product is depicted in Figure 2 and can be rectangular or in other shapes, for example Can be used as door rugs or as non-slip carpets in playgrounds and the like.

Example 3

'' Synthetic piece of turf with a metal fitter attached to the underside

Before the shaped product removed from the above-mentioned device cools down, a 90 cm wide, 8x8 woven aluminum wire mesh (wire mesh) from an overhead supply roll onto the flat surface of the molded synthetic turf applied. The linear feed rate of the grid corresponds approximately to the peripheral speed of the roller and will controlled by their speed. During the feeding of the grid from the supply roll, ee is through a tensioning device is tensioned and then runs under a press roller which the grating into the curved surface The press roller is pressed with a force of about 27 * 0 kg at the point of contact against the surface of the product. At the same time, the molded product receives external heat before it comes into contact with the mesh fed. This is done to remove the surface of the poly-

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to keep merisats in a semi-molten state and thereby allow the grating to be embedded in the bottom part and a complete bond between Grid and the molded product. The heat supplied from outside immediately after spraying is preferably radiant heat. In this example, a 2000 watt infrared lamp about 2.5 to 5 cm above the forming drum is sufficient to generate the Surface of the polymer in a satisfactory molten state for binding the fabric keep.

During processing, the synthetic grass product is cooled to yield water can pass through the interior of the drum at a rate of 132 l / min of about 21 ⁰ C. As soon as the shaped product has ^{cooled to about 80 °} C., it is withdrawn from the drum and passed through a pair of heated metal rollers for surface treatment and wound onto a winding core to obtain large rolls of synthetic grass that are suitable for future handling and storage .

Example 4

The procedure described in Example 3 is repeated with the exception that a 90 cm wide polyester

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Fleece (28.4 to 56.8 g / 0.84 m ² ) is fed onto the flat surface of the molded synthetic turf on top of the aluminum grid via a supply roll. The feed speed of the fleece is about the same as that of the grid, when the turf, the grid and the fleece pass through the press roller, the fleece is embedded on the surface of the base between the holes in the grid and a bond is thus established. The subsequent processing and the stripping of the piece of turf from the form are carried out as described in Example 1.

Example 5

The procedure described in Example 4 is repeated with the exception that an anti-skid material is used the bottom is tied as in example 2. The resulting product is one with a metal mesh reinforced, non-slip synthetic turf.

Patent claims s

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Claims (8)

- 17 claims: 1.Three-dimensional shaped grass-like product, marked by a) a relatively flat thermoplastic base with protrusions that extend towards the top, wherein the projections are fixedly connected to the base part and are formed so that they simulate natural grass and the base part has openings distributed over its surface, and b) a pad that is connected to the underside of the base. 2. Product according to claim 1, characterized in that that the base is connected to the base part by heat welding. 3. Product according to claim 1, characterized in that the thermoplastic material is a polyolefin. 4. Product according to claim 3, characterized in that the polyolefin is polyethylene. 5. Product according to claim 3, characterized in that the base is a synthetic porous fibrous .A sheet-like structure, e.g. a woven fabric or non-woven fabric. 0098U / 1379 - 18 - 6. Product according to claim 5, characterized in that that the sheet structure is a polyester. 7. Product according to claim 5, characterized in that the fibrous sheet material is nylon. 8. Product according to claim 1, characterized in that the projections are arranged in the form of tufts, 9. Product according to claim 8, characterized in that the base part is composed of parallel strips istj which at intervals between the tufts arranged and fully connected as a component. 10. Product according to claim 5, characterized in that a relative to the underside of the sheet-like structure thin synthetic foam is attached. 11. Product according to claim 3, characterized in that a relatively thin synthetic foam on the underside attached to the base. 12. Product according to claim 3 »characterized in that that the base is a metal grid. - 19 009814/1379 - '19 - .13 · Product according to claim 12, characterized in, that the grid is made of aluminum wire. 14. Product according to claim 13, characterized in that that a relatively thin synthetic fibrous porous sheet through the openings in the grid is connected to the underside of the base part. 15. Product according to claim 14, characterized in that the sheet-like structure is a sheet of polyester fiber fleece is. 16. Product according to claim 15, characterized in that a relatively thin synthetic foam the underside of the plate made of polyester fiber fleece is attached. 17. A method of making a molded thermoplastic Artificial turf piece according to claim 1, characterized in that the in at least the semi-liquid state of the back of the base part of the removed from the molding apparatus shaped product provided with a base of the same width, this being held under a stretch which approximately corresponds to the shrinkage of the molded product on cooling, then the product with 009814/1379 - 20 - BATH ORIGINAL can undergo a PreSwalze the substrate, embedding the pad in Grundtsil, then the product is cooled by a cooling drum to approximately 80 ⁰ C and it is then allowed through a heated pair of rolls which the Vorsprüßgen, ie the blades located on the base, a permanent Bends or curls and thus gives it a tuft-like shape. 18. Use of the article according to one of the claims 1 to 16 as lawn, especially outdoors. 8 1 ^ / 1379
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