GB2287478A

GB2287478A - An artificial surface, e.g. for sports

Info

Publication number: GB2287478A
Application number: GB9404933A
Authority: GB
Inventors: Ian Beswick
Original assignee: PLAY RITE Ltd
Current assignee: PLAY RITE Ltd
Priority date: 1994-03-15
Filing date: 1994-03-15
Publication date: 1995-09-20
Also published as: GB9404933D0

Abstract

An artificial surface for sports is made by weaving a fabric 1 wherein pile threads are woven continuously and are formed into loops by warp wires, the raised pile threads being cut by a bladed wire to form a woven surface with a pile height of about 15 to 40mm. The pile threads may be of polyolefin. Hairy weft yarns (either textured filament or staple) may be used to provide a bond for adhesives and to prevent the passage of sand through the fabric. The pile-forming wires may be lubricated with wax. <IMAGE>

Description

AN ARTIFICIAL SURFACE This invention relates to a synthetic surface, particularly but not exclusively to a synthetic grass surface of the kind used for playing sports or for other leisure activities.

Synthetic grass playing surfaces are well known. It has not been possible to employ long pile tufts in known sand filled woven synthetic grass surfaces. Tufted mats have been formed by needling a pile into a pre-formed backing followed by bonding with an adhesive latex. However junctions between abutting mats have caused difficulty. Use of adhesives to secure adjacent mats have been found to be undesirable as the longevity of the resultant surface is dependent on the conditions on site during installation and also on the skill of the person making the installation. Furthermore there is a tendency for individual tufts to be stripped from the backing, particularly at the edges in use and this has led to seam failure.

According to a first aspect of the present invention a method of making an artificial surface comprises the step of weaving a backing layer wherein pile threads are run continuously integrally with the backing and the pile threads being raised above the backing by warp wires, the raised pile threads being cut by a bladed wire to form a woven surface having a pile height of 15 to 40mm.

In preferred embodiments of the invention the pile has a depth of 18 to 30mm. Preferably the backing layer is greater than about 2m wide, more preferably greater than about 3m wide.

The pile threads preferably comprise a polyolefin, for example polypropylene although polyethylene and blends or copolymers thereof may be employed.

Formation of a woven backing has the advantage that edges of the surface may be provided with woven selvedges. Fraying at the edges of the mat is eliminated and joining of adjacent mats is facilitated, for example, by sewing.

Weaving of long pile polyolefin, especially polypropylene surfaces has not previously been considered because of frictional heating of the polyolefin by the warp wires, leading to deformation or melting of the fibres. Use of conventional lubricant liquid sprays as employed in interior carpet manufacture, is not acceptable because a large amount of liquid must be used and this results in contamination of the finished product.

In a preferred embodiment of the present invention, the method includes the step of lubricating the warp wires using a solid lubricant. Use of a wax lubricant is especially preferred. Examples of suitable lubricants include paraffin waxes, blended paraffin waxes and a mixture of paraffin waxes and mineral oil.

The wires may be drawn over a body of solid lubricant during the weaving cycle. This serves to apply lubricant directly to the point of contact with the fibres reducing contamination. Furthermore the solid lubricant does not have the deleterious effects observed with liquid contaminants.

In a further preferred embodiment of the present invention the method includes the step of using hairy weft yarns. Examples of such yarns include fibres produced by the textured continuous filament route or by spinning stable fibres into a yarn in a single or multiple end form. Previously employed flat or twisted tape polypropylene wefts present a smooth surface to adhesives which are used to secure the artificial surface to a substrate or to bond edges of artificial surfaces. Use of hairy yarns provide a surprisingly strong bond strength for conventional adhesives, carrier tape joins as well as hot melted adhesive systems. Conventional wefts have also been found to form a backing containing undesirable apertures, resulting in reduced integrity of the pile because of their tendency to allow sand to pass through the apertures.Use of hairy weft yarns prevent sand passing through the woven backing layer but still allows water to drain through the mat.

The method of the present invention may be used for manufacture of golf mats, tennis courts, hockey pitches, football pitches, or other playing surfaces.

According to a second aspect of the present invention there is provided an artificial surface comprising a woven backing layer with a pile height of 40mm, preferably 15 to 30mm.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings of which: Figure 1 is a side elevation of an artificial surface made in accordance with the method of the invention, and Figure 2 is a perspective view of a woven backing of interlaced threads of warp and weft.

Referring to the drawings in detail, Figure 1 shows a side elevation of an artificial surface made in accordance with the method of the invention which comprises a woven backing layer 1 of interlaced threads of warp 2 and weft 3. The weft comprises a hairy yarn which may be formed, for example, by a textured continuous filament route or by spinning individual staple fibres into yarn in single or multiple end form. The textured continuous filament method and the method of spinning staple fibres into a yarn are well known to the skilled man and it must be understood that other techniques of texturing yarn may be used to the same effect.

Pile threads are run continuously integrally with the backing, the pile threads are raised above the woven backing by warp wires. The backing can have a width of greater than about 2m. The raised pile threads are cut by the bladed wires to form a pile height of 15mm to 40mm. Cutting of the pile threads forms tufts which imitate the appearance and feel of blades of grass. Examples of suitable synthetic materials for the pile threads include polypropylene, polyethylene, and blends or copolymers of these materials. Frictional heating of the warp wires is reduced by lubricating the warp wires with a solid lubricant such as a wax based lubricant. Examples of suitable wax based lubricants include paraffin waxes, blended paraffin waxes and a mixture of paraffin waxes and mineral oil.

Known artificial surfaces comprise tufts of twisted tape secured to a backing layer. These tufts present a flat smooth surface to a backing layer which also has a smooth surface of synthetic material. Frictional contact between the two surfaces is minimal and the bonding provided by an adhesive only produces a small increase in strength of the bond between the tufts and the backing layer. The increased surface area of a textured yarn provides a surface which grips tufts secured to the weft and minimises the risk of tufts, particularly long tufts, being pulled out of the artificial surface. Hairy yarn also provides an improved bond for an adhesive, for example a latex adhesive. Woven backing with wefts of hairy yarn virtually eliminates the presence of undesirable apertures which allow sand to pass through the backing layer. Hairy weft yarns improve the integrity of the pile.

A woven selvedge also enables adjacent or adjoining edges of artificial surface to be sewn together thereby creating a stronger join.

Claims

CLAIMS:

1. A method of manufacturing an artificial surface which comprises: (a) weaving a backing layer wherein pile threads are run continuously integrally with the backing, (b) raising the pile threads above the backing by warp wires, and (c) cutting the raised pile threads by a bladed wire to form a woven surface having a pile height of 15 to 40mm.

2. A method of manufacturing an artificial surface as claimed in claim 1, in which the pile has a depth of about 18mm to about 3Omm.

3. A method of manufacturing an artificial surface as claimed in any preceding claim, in which the backing layer is greater than about 2m wide.

4. A method of manufacturing an artificial surface as claimed in claim 1 or claim 2, in which the backing layer is greater than about 3m wide.

5. A method of manufacturing an artificial surface as claimed in any preceding claim, in which the pile threads comprise a polyolefin.

6. A method of manufacturing an artificial surface as claimed in any of claims 1 to 4, in which the pile threads comprise polypropylene.

7. A method of manufacturing an artificial surface as claimed in any of claims 1 to 4, in which the pile threads comprise polyethylene and blends or copolymers thereof.

8. A method of manufacturing an artificial surface as claimed in any preceding claim, in which edges of the artificial surface may be provided with woven selvedges.

9. A method of manufacturing an artificial surface as claimed in any preceding claim, in which joining of adjacent mats is facilitated by sewing.

10. A method of manufacturing an artificial surface as claimed in any preceding claim, in which the method further includes the step of lubricating the warp wires using a solid lubricant.

11. A method of manufacturing an artificial surface as claimed in claim 10, in which the lubricant is a wax based lubricant.

12. A method of manufacturing an artificial surface as claimed in claim 10, in which the lubricant includes: paraffin waxes, or blended paraffin waxes, or a mixture of paraffin waxes and mineral oil.

13. A method of manufacturing an artificial surface as claimed in any preceding claim, in which the wires are drawn over a body of solid lubricant during the weaving cycle.

14. A method of manufacturing an artificial surface as claimed in any preceding claim, in which the method includes the step of using hairy weft yarns.

15. A method of manufacturing an artificial surface as claimed in claim 14, in which the hairy weft yarns include fibres produced by the textured continuous filament route, or by spinning stable fibres into a yarn in a single or multiple end form.

16. A method of manufacturing an artificial surface as claimed in any preceding claim, in which the pile threads comprise flat or twisted tape polypropylene wefts.

17. An artificial surface comprising a woven backing layer with a pile height of about 40mm.

18. An artificial surface as claimed in claim 17, in which the pile height is about 15mm to about 30mm.

19. An artificial surface comprises: a woven backing layer with a plurality of pile threads extending upwardly from said backing layer to simulate a grass surface, wherein said woven backing layer comprises a plurality of interwoven warp and weft threads, at least one of said warp or weft threads comprising a hairy yarn.

20. An artificial surface as claimed in claim 19, in which the pile threads comprise flat or twisted tape polypropylene.

21. A golf mat comprising an artificial surface as claimed in claim 19 or claim 20.

22. A tennis court comprising an artificial surface as claimed in claim 19 or claim 20.

23. A hockey pitch comprising an artificial surface as claimed in claim 19 or claim 20.

24. A football pitch comprising an artificial surface as claimed in claim 19 or claim 20.

25. An artificial surface as substantially hereinbefore described with reference to the accompanying drawings.