GB2361421A

GB2361421A - Mat incorporating a recycled mat

Info

Publication number: GB2361421A
Application number: GB0008293A
Authority: GB
Inventors: Terence Michael Hedley
Original assignee: Walk Off Mats Ltd
Current assignee: Walk Off Mats Ltd
Priority date: 2000-04-05
Filing date: 2000-04-05
Publication date: 2001-10-24
Also published as: AU4261801A; GB0008293D0; WO2001074206A3; WO2001074206A2

Abstract

A mat includes a recycled mat 2 having a fabric layer 8 and a rubber backing layer 10, the fabric layer 8 being encapsulated between a lower rubber layer 4 and an upper rubber layer 6, wherein the mat comprises a layer of foamed rubber material. A method of manufacture and a method of recycling a mat are also disclosed.

Description

2361421 MAT, METHOD OF MANUFACTURING A MAT AND METHOD OF RECYCLING MATS

According to the present invention there is provided a mat, a method of manufacturing a mat and a method of recycling mats.

In particular, but not exclusively, a first aspect of the invention provides an anti-fatigue mat. This is a resilient mat that provides a cushioned surface on which a person can stand. Such mats are used for example by workers who have to stand in one place for prolonged periods. The cushioned surface allows the worker's feet to move, which improves circulation of the blood and reduce fatigue in the legs and feet.

According to a second aspect of the invention there is provided a method of manufacturing a mat and in particular, but not exclusively, an anti-fatigue mat.

According to a third aspect of the invention there is provided a method of recycling mats, in particular, but not exclusively, worn out, rejected or scrapped rubber-backed dust control mats of the type having a tufted fabric layer bonded to a rubber backing layer.

A method of recycling mats is described in International patent application No. W094/10888.

In that method, two worn out rubber-backed dust control mats are placed face-to-face with the fabric layers innermost and then bonded to one another around the peripheries of the mats. Air is trapped within the fabric pile, between the two rubber backing layers, giving the mat some resilience. Alternatively, instead of using two mats, a solid rubber sheet may be placed over the fabric face of a single mat then bonded to the periphery of the mat to produce a similar effect.

We have found that in practice such mats have very little resilience or compressibility and only limited anti-fatigue properties. It is believed that this is because the tufted fabric layer is compressed during the bonding process, which is carried out in a heated press, with the result that most of the air is expelled. This is particularly so with mats having a cotton fabric layer, which when recycled using this method have virtually no compressibility, resilience or antifatigue properties. Such mats are not therefore suitable for use in the recycling process and are generally thrown away when they are worn out.

2 It is an object of the present invention to provide a mat, a method of manufacturing a mat and/or a method of recycling mats that mitigates at least one of the aforesaid disadvantages.

According to the present invention there is provided a mat including a recycled mat having a fabric layer and a rubber backing layer, and a rubber layer that covers and encapsulates the fabric layer of the recycled mat, characterised in that said mat includes a layer of foamed rubber material. The foamed rubber material increases the resilience of the mat, making it more effective as an anti-fatigue mat. Further, the increased resilience of the rubber material means that old cotton mats, with very little natural resilience, can be successfully recycled and converted into anti-fatigue mats.

Advantageously, the layer of foamed rubber material has a thickness of 1-5mm, preferably approximately 2mm.

Advantageously, the recycled mat is encapsulated between a lower rubber layer and an upper rubber layer. Advantageously, each of said lower and upper rubber layers includes a foamed rubber material. It has been found that such mats are dimensionally stable and do not curl.

Advantageously, said upper rubber layer includes a capping layer of solid rubber material. This gives improved abrasion resistance.

Advantageously, surface formations are provided on the upper face of the upper rubber layer, to provide a non-slip surface.

Advantageously, the mat includes a textile sheet between the backing layer and the adjacent rubber layer. This helps air to escape from between the adjacent rubber layers during the pressing and bonding process. Advantageously, the textile sheet includes a sheet of nonwoven polyester material, although other materials such as knitted polyester fabric may also be used.

Advantageously, the recycled mat is inverted, with the fabric layer downwards and the rubber backing upwards. The rubber backing layer is bonded to the upper rubber layer, increasing the durability and wear resistance of that layer.

Advantageously, the recycled mat includes a tufted fabric layer, preferably of tufted polyester, nylon or cotton or any combination thereof 3 Advantageously, the mat is an anti-fatigue floor mat.

According to another aspect of the invention there is provided a method of manufacturing a mat wherein a recycled mat having a fabric layer and a rubber backing layer is bonded to a rubber layer such that the rubber layer covers and encapsulates the fabric layer of the recycled 5 mat, characterised in that the mat includes a layer of foamed rubber material.

Advantageously, the recycled mat is bonded to said rubber layer in a heated press.

Advantageously, said rubber layer includes a foaming agent and, during the bonding process, the foaming agent is activated to cause foaming of said rubber layer.

Advantageously, said recycled mat is encapsulated between an upper rubber layer and a lower 10 rubber layer.

Advantageously, each of said upper and lower rubber layers includes a foaming agent that is activated during the bonding process to cause foaming of said layers.

Advantageously, said upper rubber layer includes a capping layer of solid rubber material.

Advantageously, surface formations are formed on the upper face of the upper rubber layer.

Advantageously, a textile sheet is included between the backing layer and the adjacent rubber layer.

Advantageously, the textile sheet includes a sheet of non-woven polyester material.

Advantageously, the recycled mat is inverted.

Advantageously, the recycled mat includes a tufted fabric layer.

Advantageously, the recycled mat includes a fabric layer of tufted polyester, nylon or cotton or any combination thereof.

According to another aspect of the invention there is provided a method of recycling a mat, wherein a recycled mat having a fabric layer and a rubber backing layer is bonded to a rubber layer such that the rubber layer covers and encapsulates the fabric layer of the recycled mat, 4 thereby providing a new mat, characterised in that the new mat includes a layer of foamed rubber material.

An embodiment of the present invention will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. I is a plan view of a mat; Fig. 2 is a cross-section along line 11-11 of figure 1; Fig. 3 is a cross-section along line 111-111 of figure I at an enlarged scale, and Fig. 4 is an exploded view of a laid-up mat in a press, during the manufacturing process.

As shown in figures 1-3, the anti-fatigue mat includes an old recycled mat 2, which is encapsulated between two layers 4,6 of foam rubber.

The recycled mat 2 includes a fabric layer 8 of tufted nylon, polyester, cotton or a mixture of those fibres on a substrate of non-woven polyester, which is bonded to a backing layer 10 of nitrile rubber. Such mats are commonly referred to as dust control mats and are placed at the entrances of buildings to remove dust and moisture from the feet of pedestrians entering the building. The recycled mat 2 is arranged upside down within the anti-fatigue mat of the present invention, with the fabric layer 8 underneath and the rubber backing layer 10 on top.

The lower and upper layers 4,6 of foam rubber extend beyond the periphery of the recycled mat 2 and the edges 12 of those layers are bonded together, to encapsulate the recycled mat. A sheet of textile material 14 is included between the backing layer 10 and the upper foam rubber layer 6, to allow trapped air and other gases to escape from between those layers during the manufacturing process. This textile sheet 14 extends beyond the lower and upper rubber layers 4,6 and may for example be a sheet of non-woven polyester having a weight of 25g/m'. Alternatively, a knitted polyester sheet may be used. A small amount of air remains trapped within the fabric layer 8 of the recycled mat 2, between the rubber backing layer 10 and the lower layer 4 of foam rubber. This trapped air gives the mat some resilience, further resilience being provided by the gas bubbles in the foam rubber.

The upper foam rubber layer 6 is bonded to the rubber backing layer 10 through the textile sheet 14. This upper foam layer 6 has a thin cap 16 of solid rubber, for improved abrasion resistance. The upper face of the upper layer 6 is profiled, having a number of raised ribs, studs or other formations 18 moulded on its surface.

A method of manufacturing an anti-fatigue mat will now be described with reference to figure 4, which is a schematic exploded cross-section of a lay up in a heated press. The press includes a heated metal platen 20 located below an inflatable diaphragm 22.

The lay up consists of the following items placed in order on the heated platen 20: a lower release sheet 24, the lower layer 4 of foamable rubber, the recycled mat 2, the textile sheet 14, the upper layer 6 of foamable rubber with the cap 16, a texture sheet 26, and an upper release sheet 28. It will be noticed that the mat is laid up so that the lower layer 4 of foamable rubber is nearer to the heated platen 20, so that in the finished mat this layer is flat.

The lower and upper layers 4,6 are unfoamed prior to the pressing operation and consist of solid sheets of nitrile rubber that includes heat-activated foaming agents, for example azobicarbonamides and sulphonyl hydrazides. During the pressing operation, heat from the press activates the foaming agent causing it to release a gas that foams the rubber. As a result of foaming the thickness of each rubber layer increases from approximately Imin to approximately 2mm.

The upper rubber layer 6 includes the cap 16 of solid rubber and is made by calendering together a 0.6mm. thick sheet of rubber that includes a foaming agent with a 0,4mm thick sheet of rubber that does not include a foaming agent. The process for calendering together two sheets of rubber is well known and will not be described in more detail.

The press is heated to a temperature of about 170'C. The diaphragm 22 is then inflated, for example to a pressure of 40 pounds per square inch, pressing the mat against the heated platen 20, typically for a cycle time of 30 minutes.

The heat from the platen 20 softens and cures the lower and upper rubber layers 4,6 and the pressure from the diaphragm 22 presses and bonds the edges 12 of those layers together around the periphery of the mat, thereby encapsulating the recycled mat 2. The upper layer 6 is also bonded to the rubber backing 10 of the recycled mat 2 through the textile sheet 14. At the 6 same time, the heat activates the foaming agent, causing the rubber material in the lower and upper layers 4,6 to foam. The textile sheet 14 allows air and other gases trapped between the upper layer 6 and the backing layer 10 to vent outwards to the periphery of the mat.

The texture sheet 26 has a plurality of apertures (not shown) into which the rubber of the upper layer 6 flows during the pressing operation, creating the formations 18 that make up the surface texture on the upper surface of the mat 2. The texture sheet 26 consists, for example, of a perforated or embossed metal plate.

The lower and upper release sheets 24,28 consist of PTFE-coated woven glass fabric. These sheets prevent the rubber layers 4,6 from sticking to the platen 20 and the diaphragm 22, and also impart a woven fabric imprint to the faces of the mat.

After pressing, the mat is removed from the press and allowed to cool, after which the edges 12 of the mat are trimmed, for example using a guillotine or a die cutter.

In some types of press (not shown), the positions of the metal platen and the diaphragm are reversed, the heated metal platen being located above the inflatable diaphragm. In that case, the mat is laid up in the opposite order with the recycled mat the other way up, so that the lower foam rubber layer 4 is on the platen side of the press. The process for making the mat is otherwise substantially as described above.

The mat and the manufacturing process may be modified in various different ways, some of which will now be described.

The upper and/or lower foam layers 4,6 may incorporate granulated rubber from recycled mats or trimmings resulting form the mat manufacturing process, to increase the proportion of recycled material used.

Vents may optionally be provided at one or more locations around the periphery of the mat, to improve the venting of trapped air and other gases from the mat during the pressing operation. These vents may be formed by inserting one or more strips of PTFE-coated woven glass fabric 30 between the recycled mat 2 and the upper layer 4, so that they extend outwards beyond the edge 12 of the mat. These strips form vents 14 that allow air to escape from between the layers during the pressing operation. After pressing, the strips are removed prior to the final trimming operation.

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Claims

1. A mat including a recycled mat having a fabric layer and a rubber backing layer, and a rubber layer that covers and encapsulates the fabric layer of the recycled mat, characterised in that said mat includes a layer of foamed rubber material.

2. A mat according to claim 1, wherein the layer of foamed rubber material has a thickness of 1-5mm, preferably approximately 2mm.

3. A mat according to claim 2, wherein the recycled mat is encapsulated between a lower rubber layer and an upper rubber layer.

4. A mat according to claim 3, wherein each of said lower and upper rubber layers includes a foamed rubber material.

5. A mat according to claim 3 or claim 4, wherein said upper rubber layer includes a capping layer of solid rubber material.

6. A mat according to any one of claims 3 to 5, wherein surface formations are provided on the upper face of the upper rubber layer.

7. A mat according to any one of claims 3 to 6, including a textile sheet between the backing layer and the adjacent rubber layer.

8. A mat according to claim 7, wherein the textile sheet includes a sheet of non-woven polyester material.

9. A mat according to any one of the preceding claims, wherein the recycled mat is inverted.

10. A mat according to any one of the preceding claims, wherein the recycled mat includes a tufted fabric layer.

11. A mat according to any one of the preceding claims, wherein the recycled mat includes a fabric layer of tufted polyester, nylon or cotton or any combination thereof.

12. A mat according to any one of the preceding claims, wherein the mat is an anti-fatigue floor mat.

13. A mat substantially as described herein with reference to and as illustrated by the accompanying drawings.

14. A method of manufacturing a mat wherein a recycled mat having a fabric layer and a rubber backing layer is bonded to a rubber layer such that the rubber layer covers and encapsulates the fabric layer of the recycled mat, characterised in that the mat includes a layer of foamed rubber material.

15. A method according to claim 14, wherein said recycled mat is bonded to said rubber layer in a heated press.

16. A method according to claim 14 or claim 15, wherein said rubber layer includes a foaming agent and, during the bonding process, the foaming agent is activated to cause foaming of said rubber layer.

17. A method according to any one of claims 14 to 16, wherein said recycled mat is encapsulated between an upper rubber layer and a lower rubber layer.

18. A method according to claim 17, wherein each of said upper and lower rubber layers includes a foaming agent that is activated during the bonding process to cause foaming of said layers.

19. A method according to claim 17 or claim 18, wherein said upper rubber layer includes a capping layer of solid rubber material.

20. A method according to any one of claims 17 to 19, wherein surface formations are formed on the upper face of the upper rubber layer.

21. A method according to any one of claims 17 to 20, wherein a textile sheet is included between the backing layer and the adjacent rubber layer.

22. A method according to claim 2 1, wherein the textile sheet includes a sheet of non woven polyester material.

23. A method according to any one of claims 14 to 22, wherein the recycled mat is inverted.

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24. A method according to any one of claims 14 to 23, wherein the recycled mat includes a tufted fabric layer.

25. A method according to any one of claims 14 to 24, wherein the recycled mat includes a fabric layer of tufted polyester, nylon or cotton or any combination thereof.

26. A method of manufacturing a mat, the method being substantially as described herein with reference to and as illustrated by the accompanying drawings.

27. A method of recycling a mat, wherein a recycled mat having a fabric layer and a rubber backing layer is bonded to a rubber layer such that the rubber layer covers and encapsulates the fabric layer of the recycled mat, thereby providing a new mat, characterised in that the new mat includes a layer of foamed rubber material.