WO2003055377A1

WO2003055377A1 - Dust control mat

Info

Publication number: WO2003055377A1
Application number: PCT/GB2002/005838
Authority: WO
Inventors: David Neil Pollington; Peter Charles Brazier; Terence Michael Hedley
Original assignee: Milliken Industrials Limited
Priority date: 2001-12-21
Filing date: 2002-12-20
Publication date: 2003-07-10
Also published as: GB0130607D0; AU2002353191A1

Abstract

A dust control mat includes an upper wear layer (1) and a lower backing layer (2). The upper layer (1) includes a dust control portion (3) comprising a tufted pile textile material and an image bearing portion (4) that is adapted to carry a high resolution printed image. The dust control portion (3) and the image bearing portion (4) are both permanently bonded to backing layer (2).

Description

DUST CONTROL MAT

The present invention relates to a dust control mat that is capable of bearing a high resolution printed image and in particular, but not exclusively, to a mat that is capable of bearing a printed image with a resolution of at least 75dpi.

Dust control mats are usually placed at the entrances to shops, offices and other buildings, to remove dust and dirt from the feet of pedestrians entering the building.

Dust control mats having a tufted pile surface are well known, one example of such a mat being described in EP 0847327 A. Such mats have an tufted pile textile surface, typically of tufted nylon, which is bonded through the application of heat and pressure to a rubber backing layer. The pile length is typically 8-15mm. Such mats have extremely good dust control properties and can be washed by immersion and agitation in water.

Logo or message bearing mats have been created by forming the textile surface from a mosaic of tufted materials of different colours. The resulting mats are very smart in appearance, provide good dust control properties and are both washable and hard wearing. However, the process used to create such mats is expensive and the original logo or image may need to be altered to optimise the product for wear resistance.

A more complicated pattern or image can be applied to the mat by printing the textile surface. However, because the tufted pile can move during and after printing, the observable resolution of the printed image may be much lower than the theoretical resolution of the image printed by the printer. In practice, the maximum observable resolution that can be achieved is no higher than about 20dpi (dots per inch). The images that can be printed on the mats are therefore limited to relatively simple patterns and logos.

It is also known to produce a floor mat with a surface that can carry a higher resolution image, such as a photographic image or an advertising message. Such mats are sometimes called poster mats or advertising mats. These mats generally have a textile surface with either no pile or only a very short pile, since a longer pile is not capable of supporting a high resolution image. As a result, they generally have poor dust control properties. A process for manufacturing a printed mat is described in WO 01/25524. In that process, an image is printed onto a transfer sheet using sublimatic dyes, and then transferred to the textile surface of the mat during the backing process. The textile surface may be a tufted fabric, a woven fabric or a non-woven fabric (e.g. a felt or spun bonded fabric). Where the fabric is a tufted fabric, the resolution of the image depends on the length of the pile and degrades as the pile length increases, owing to movement of the pile after printing.

It is known from WO 00/15085 to provide a mat having a non slip backing layer, a top liquid absorbent textile surface and an intermediate stabilization layer . The backing layer is preferably nitrile rubber, the intermediate stabilization layer may be heat curable non- woven polyester and the textile surface can include a printed image or an advertising message viewable from above. A sublimation printing process is described. The textile surface may be formed from polyester with a pile height in the range 3 to 7 mm. It may be a needlefelt material. Apart from a small exposed rubber border, the textile surface is the same size as the backing layer. The mat has poor dust control properties.

A mat with superior wear resistance and improved image durability is described in GB 2360248 A. Here the polyester needlefelt textile surface is replaced by a knitted polyester textile, which is sanded to render it smooth for printing and treated to make ithydrophilic. The textile is substantially the same size as the backing material and printed optical borders may be provided. The mats may be utilized as drip mats, table cloths or floor mats. However, this type of surface textile, like that in WO 00/15085, is unsuitable for dust control applications.

The is a need therefore for an effective dust control mat that is capable of bearing a high resolution printed image.

According to the present invention there is provided a dust control mat including an upper wear layer and a lower backing layer, wherein the upper layer includes a dust control portion comprising a tufted pile textile material and an image bearing portion that is adapted to carry a high resolution printed image, the dust control portion and the image bearing portion both being permanently affixed to the mat.

The mat has good dust control properties and is capable of carrying a high resolution image, allowing it to be used as a poster mat or an advertising mat. Because the dust control portion and the image bearing portion are both permanently bonded to backing layer, the mat can be laundered in the same way as a conventional dust control mat. The cost of manufacturing the mat is also similar to that of a conventional dust control mat.

Advantageously, the tufted pile textile material has a pile length of 8-15mm, and a pile weight of 400-1100gm^"2, preferably 500-800gm^"2. The tufted pile textile material may include a woven or non-woven substrate having a weight of 80-130gm^"2, preferably approximately 1 OOgrn^"2. Advantageously, the tufted pile textile material has a stitch density in the range 500-1500 stitches per 100cm², preferably 645-1000 stitches per 100cm². These characteristics provide very good dust control properties.

Advantageously, the image bearing portion comprises a fabric material having either no pile or a pile length of less than 5mm, preferably less than 1mm. The image bearing portion may consist of a knitted fabric material, for example a knitted polyester material, with either no pile or a pile length of less than 1 mm. It is essential for good print resolution that the fabric has either no pile or a very short pile, since the pile may move during use, so disturbing the printed image. We have found that knitted polyester material is particularly suitable, since the polyester material has a smooth surface that is very receptive to the printing dyes. The surface may be pile-less or the surface may be raised slightly, for example by sanding or hydraulic napping, to produce a short pile.

Alternatively, the image bearing portion may consist of a tufted pile fabric material, for example a tufted pile polyester fabric with a pile height of less than 5mm. We have found that this material is also suitable, providing that the pile length is sufficiently short.

Alternatively, the image bearing portion may consist of a woven fabric, for example woven polyester, or a non-woven fabric material, for example needlefelt or spun bonded fabric.

The fabric material may include a soil-release agent or may have a protective cover layer, to reduce or prevent soiling.

Alternatively, the image bearing portion may consist of a flexible film material, for example an elastomer material such as rubber, or a polymer such as PVC.

Advantageously, the area of the image bearing portion lies in the range 8-33%, preferably

8-25%, of the total mat area. This ensures that the image bearing portion is large enough to carry a highly visible image, without significantly affecting the dust control properties of the mat. Preferably, the area of the image bearing portion lies in the range 0.125m² to 1m².

Advantageously, the image bearing portion is capable of carrying a printed image having an observable resolution of at least 75dpi, preferably at least 150dpi, more preferably approximately 300dpi or higher (respectively 30, 59 and 118 dots per cm). Advantageously, the image bearing portion carries a printed image. The printed image may be formed from sublimatic dyes, for example by transfer printing, or from UV curable inks or other dyes and inks.

Advantageously, the backing layer comprises a sheet of synthetic or natural rubber, preferably nitrile rubber. The dust control portion and the image bearing portion are preferably both vulcanised to the rubber backing layer. The backing layer may have a thickness of 0.75-3.0 mm.

According to another aspect of the invention there is provided a method of making a dust control mat, comprising the steps of assembling an upper wear layer that includes a dust control portion comprising a tufted pile textile material and an image bearing portion that is adapted to carry a high resolution printed image, and bonding the upper layer to a lower backing layer such that the dust control portion and the image bearing portion are both permanently affixed to the mat.

Advantageously, the lower backing layer comprises a sheet of rubber, and the upper wear layer is bonded to the lower backing layer by vulcanising the rubber in a heated press.

The image bearing portion is preferably located within a cut-out in the dust control portion. Preferably, the image bearing portion and the dust control portion are located in an abutting relationship.

Advantageously, the image bearing portion is printed with an image having an observable resolution of at least 75dpi, preferably at least 150dpi, more preferably approximately 300dpi or higher. The image bearing portion is preferably printed by a transfer printing process using sublimatic dyes. Preferably, the image bearing portion is printed after it has been bonded to the backing layer, to prevent any degradation of the printed image during subsequent process steps. Alternatively, the image bearing portion may be printed before or during the backing process. Advantageously, the image bearing portion is covered after printing with a protective cover.

According to another aspect of the present invention there is provided a dust control mat having a backing and a textile surface comprising at least one tufted area and at least one relatively smooth area that is printed or suitable for printing, characterised in that the relatively smooth area is permanently affixed to the mat.

The combination of tufted and relatively smooth areas in a single mat provides regular dust control properties (removal and control of soil and water from pedestrians and vehicles etc.) with an area which is suitable for high resolution image or logo reproduction.

The dust control area of the mat may be made from various textile materials such as nylon, cotton, polyester etc. and is usually tufted into a substrate material of non woven polyester or alternatively a woven substrate of polyester, polypropylene etc.

The printable or printed area of the mat can be made of many different materials, not limited to textiles, although for washability textiles would normally be used. This material must be capable of carrying high resolution images, and is preferably suitable for bonding to a rubber backing layer and able to provide sufficient wash and abrasion resistance to prevent the appearance of the logo or image deteriorating with wear. Examples of suitable materials are mostly polyester based as they exhibit good properties for sublimatic transfer printing: they can be woven, knitted, flocked or non-woven. Alternatively a high-density smooth surfaced tufted material could be used. In place of polyester, alternative textile materials such as nylon could be used. Blends of polyester with other fibres to enhance the print quality are also contemplated.

The backing layer may be made from a natural or synthetic rubber, preferably a nitrile rubber compound. The rubber may be foamed or unfoamed. The rubber preferably has a thickness in the range 0.75 to 3 mm. An anti-bacterial, anti-microbial and/or anti- pathogenic agent may be added to the textile and/or the rubber layer. For example the anti-bacterial agent may be added during the chemical treatment of the textile. Although it is preferred that the backing is made from natural or synthetic rubber, it is contemplated that other liquid impervious or impermeable materials could be used, such as olefins, urethanes, acrylics, latexes, plastics, PVC and the like. Furthermore, the backing may be glued to the textile layers. The backing layer may be applied by other means than vulcanisation or adhesion if an intermediate stabilization layer is used. For example, it could be extruded, knife coated, laminated, calendered, spray coated, foam coated or the like.

According to another aspect of the present invention there is provided a mat production process consisting of laying up a mat with a rubber backing layer and at least two types of top surface textile, one being a tufted textile and one being a printable relatively smooth woven, non-woven or knitted polyester textile. Preferably the textiles are in abutting relationship and cover the whole of the surface of the backing, with the exception of an exposed rubber border area. The mat is advantageously manufactured in a process wherein the uncured rubber backing sheet is cured and bonded to the printable textile and the tufted textile at the same time in a heated press.

As an alternative to cutting a window in the tufted textile, one could also lay a cut out of unvulcanised rubber on top of the tufts, place the relatively smooth printable textile onto this and vulcanise the printable area to the top of the pile. This would enable the image to be created on a surface which is level with or above the top of the pile. A suitable thickness of rubber would be in the range 1 to 5 mm, preferably about 3 mm, to prevent distortion of the rubber surface through movement of the pile underneath.

Yet another alternative would be to cut a window in the tufted textile and add an additional rubber layer into the window onto the backing layer to raise the height of the rubber in this area compared to the rest of the mat. The advantage of this construction is that, in use, water would tend to run off the raised area into the surrounding pile so that a puddle would not form on the image. Advantageously, a reinforcement layer of non woven fabric is laid between the two rubber layers to allow escape of any gases. This reinforcement layer also mitigates against rippling of the mat due to differential shrinkage after manufacture on cooling of the thicker rubber area and the thinner rubber/textile area.

The image can be created by transfer printing, ink jet printing, carpet printers, screen- printing and other similar technologies. In a preferred process the image would be printed after the mat has been fully fabricated. However it could also be printed before inserting the image bearing portion into the mat, or even sublimation printed during the vulcanisation process. Particularly where printing occurs before completion of the mat, it is possible to provide the relatively smooth textile with a textured surface, which may be formed by pressing the textile layer against a texture sheet during the curing and bonding process in the heated press.

Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 is a plan view of a mat with a printed central portion;

Figure 2 is a plan view of a mat with multiple printed portions;

Figure 3 is a cross sectional side elevation of the mat of figure 1 , and

Figure 4 is a cross sectional side elevation of a partially constructed mat laid up in a press.

The mat shown in figures 1 and 3 includes an upper wear layer 1 , which is bonded to a backing layer 2 of vulcanised nitrile rubber. Optionally, the backing layer 2 may be slightly larger than the upper layer 1 , leaving a rubber border (not shown) that extends around the periphery of the mat. The overall size of the mat is typically 85cm x 150cm.

The upper wear layer 1 includes an outer dust control portion 3 and an inner image bearing portion 4, that fits into a rectangular window 5 cut into the dust control portion 3. The dust control portion 3 and the image bearing portion 4 are both bonded directly to the backing layer 2. An image 6 is printed onto the image bearing portion 4.

The dust control portion 3 comprises a tufted pile textile, for example of solution dyed high twist nylon, which is tufted onto a substrate (not shown), for example of non-woven polyester or woven polyester or polypropylene. Typically the tufted pile textile material has a pile length of 8-15mm, and a pile weight of 400-110Ogm^"2. The substrate typically has a weight of approximately 100gm^"2. The stitch density of the tufted pile textile material is usually 645-1000 stitches per 100cm². A textile with these characteristics provides very good dust control properties. Alternatively, the dust control textile can include tufts of polyester, cotton or a blend of these and other fibres.

The image bearing portion 4 is preferably made of micro-knitted polyester, and is optionally sanded or hydraulically napped to provide a smooth felted surface. The pile length of the napped surface is however very short, being less than 1mm.

Alternatively, the image bearing portion 4 may be made of a tufted pile fabric material such as tufted polyester with a pile length of less than 5mm, or a woven fabric such as woven polyester, or flocked, or non-woven fabric material such as needlefelt or spun bonded fabric. The fabric material may include a soil-release agent or may have a protective cover layer, for example of polyethylene or PVC, to reduce soiling.

Alternatively, the image bearing portion 4 may consist of a flexible film material, for example an elastomer material such as white rubber or a polymer such as PVC.

It is important that the image bearing portion 4 does not occupy too much of the mat surface, as this would adversely affect the dust control properties of the mat. Preferably, the area of the image bearing portion 4 lies in the range 8-33% of the total mat area (it should be noted that the drawings are not to scale). This ensures that the dust control portion 3 is sufficiently large to provide good dust control properties, while the image bearing portion is large enough for strong visual impact. For example, a typical mat may have a total surface area of 1-3m², and the area of the image bearing portion 3 will generally lie in the range 0.125m² to 1m², corresponding to paper sizes A3 to A0.

The image 6 carried by the image bearing portion 4 has an observable resolution of at least 75dpi, preferably at least 150dpi, more preferably approximately 300dpi or higher. The printed image may be formed from sublimatic dyes, for example by transfer printing, or from UV curable or other dyes and inks.

Figure 3 is a sectional side view of the mat shown in figure 1. The rubber backing layer 2 is shown, together with the tufted areas of the dust control portion 3, which are located towards the periphery of the mat. A printable polyester textile forming the image bearing portion 4 is situated in the central window 5 where there is no tufted textile. The printable textile has a logo or other image printed onto its surface. The tufted textile and the printable textile are abutted to form a continuous stepped top surface for the mat. The height of the tufted textile is greater than that of the printable material.

The mat may alternatively be formed with multiple image bearing portions 4, as shown in figure 2. Here the tufted pile dust control portion 3 has a number of widows 5 cut in it and these are filled with printable textile, each of which carries a printed logo 6.

The mat is manufactured by cutting out and assembling a dust control portion and a complementary image bearing portion to form the upper wear layer, and then vulcanising the upper wear layer to a rubber backing layer in a heated press. A laid up mat assembly in a press is shown in Figure 4. The assembled upper wear layer 1 is laid on a backing sheet 2 of uncured rubber, prior to being placed in a heated press. The laid up mat assembly may be covered by top and bottom release sheets 7,8, for example of PTFE-coated woven glass, to prevent it sticking to the press. The press consists of a heated metal platen 9 and an inflatable diaphragm 10, which is secured to an upper plate 11.

The laid-up mat assembly is pressed in the heated press, for example at a temperature of 170EC and a pressure of 30 pounds per square inch, applied for a cycle time of six minutes. The heat from the press bonds the upper wear layer 1 to the rubber backing sheet 2 and at the same time vulcanises the rubber to form the backing layer. The mat is then removed from the press and allowed to cool, after which the release sheets 7,8 are removed and, if necessary, the edges of the backing layer 2 are trimmed. Optionally, the mat may then be laundered, to raise the pile of the dust control fabric.

The polyester fabric forming the image bearing portion 4 is then printed with a high- resolution image, for example using a sublimatic printing process. The sublimatic printing process comprises printing a computer generated design onto a transfer paper, either directly by digital printing, or via the creation of screens which may be colour separated for high speed operation. The transfer paper is then placed face down onto the image bearing portion 4 and the dye is transferred onto the fabric by applying a heated platen to the reverse face of the paper. The dye sublimes from the paper to the relatively smooth surface of the image bearing portion and produces a mirror image of the original design on the textile. Dyes can be selected which require no further fixing or washing to finish the article being printed.

The finished mat now includes a dust control portion 3 of tufted nylon pile with optimal soil and water collection performance and an image bearing portion 4 within the dust control portion 3 that contains a high resolution image or logo 6. If required, coating of polyethylene or PVC may be applied to the image bearing portion, to protect the printed image.

Various modifications of the product and the process are of course possible, some of which will now be described. The mat may be provided with rubber borders, or it may be borderless, in which case printed "optical borders" may be provided. The image bearing portion may also have different shapes, including for example circular, triangular or irregular shapes, to fit into a correspondingly shaped window in the dust control textile. Alternatively, the image bearing portion may be located outside the dust control textile, for example towards one edge of the mat. The image bearing portion may also be slightly smaller than the window in the dust control textile, to create a rubber border between the image bearing portion and the dust control portion.

Claims

1. A dust control mat including an upper wear layer and a lower backing layer, wherein the upper wear layer includes a dust control portion comprising a tufted pile textile material and an image bearing portion that is adapted to carry a high resolution printed image, the dust control portion and the image bearing portion both being permanently affixed to the mat.

2. A dust control mat according to claim 1 , wherein the tufted pile textile material has a pile length of 8-15mm.

3. A dust control mat according to claim 1 or claim 2, wherein the tufted pile textile material has a pile weight of 400-1100gιrT², preferably 500-800gm^"2.

4. A dust control mat according to any one of the preceding claims, wherein the tufted pile textile material includes a woven or non-woven substrate having a weight of 80-130gm^"2, preferably approximately 100gm^"2.

5. A dust control mat according to any one of the preceding claims, wherein the tufted pile textile material has a stitch density in the range 500-1500 stitches per 100cm², preferably 645-1000 stitches per 100cm².

6. A dust control mat according to any one of the preceding claims, wherein the image bearing portion comprises a fabric material having either no pile or a pile length of less than 5mm, preferably less than 1mm.

7. A dust control mat according to claim 6, wherein the image bearing portion comprises a knitted fabric material.

8. A dust control mat according to claim 7, wherein the image bearing portion comprises a knitted polyester material.

9. A dust control mat according to claim 8, wherein the knitted polyester material has a napped surface with a pile height of less than 1 mm.

10. A dust control mat according to claim 6, wherein the image bearing portion comprises a tufted pile fabric material.

11. A dust control mat according to claim 10, wherein the image bearing portion comprises a tufted pile polyester fabric with a pile height of less than 5mm.

12. A dust control mat according to claim 6, wherein the image bearing portion comprises a woven or non-woven fabric material.

13. A dust control mat according to any one of claims 6 to 12, wherein the fabric material includes a soil-release treatment.

14. A dust control mat according to any one of claims 6 to 12, wherein the fabric material has a protective cover layer.

15. A dust control mat according to any one of claims 1 to 5, wherein the image bearing portion comprises a flexible film material.

16. A dust control mat according to claim 15, wherein the image bearing portion comprises an elastomer material.

17. A dust control mat according to any one of the preceding claims, wherein the area of the image bearing portion lies in the range 8-33%, preferably 8-25%, of the total mat area.

18. A dust control mat according to any one of the preceding claims, wherein the area of the image bearing portion lies in the range 0.125m² to 1m².

19. A dust control mat according to any one of the preceding claims, wherein the image bearing portion is capable of carrying a printed image having an observable resolution of at least 75dpi, preferably at least 150dpi, more preferably approximately 300dpi.

20. A dust control mat according to any one of the preceding claims, wherein the image bearing portion carries a printed image.

21. A dust control mat according to claim 19 or claim 20, wherein the printed image is formed from sublimatic dyes.

22. A dust control mat according to any one of the preceding claims, wherein the backing layer comprises a sheet of synthetic or natural rubber, preferably nitrile rubber.

23. A dust control mat according to claim 22, wherein the dust control portion and the image bearing portion are both vulcanised to the rubber backing layer.

24. A dust control mat according to any one of the preceding claims, wherein the backing layer has a thickness of 0.75-3.0 mm.

25. A method of making a dust control mat, comprising the steps of assembling an upper layer that includes a dust control portion comprising a tufted pile textile material and an image bearing portion that is adapted to carry a high resolution printed image, and bonding the upper wear layer to a lower backing layer, such that the dust control portion and the image bearing portion are both permanently affixed to the mat.

26. A method according to claim 25, wherein the lower backing layer comprises a sheet of rubber, and the upper wear layer is bonded to the lower backing layer by vulcanising the rubber in a heated press.

27. A method according to claim 25 or claim 26, wherein the image bearing portion is located within a window in the dust control portion.

28. A method according to claim 27, wherein the image bearing portion and the dust control portion are located in an abutting relationship.

29. A method according to claim 25, claim 26 or claim 27, wherein the image bearing portion is printed with an image having an observable resolution of at least 75dpi, preferably at least 150dpi, more preferably approximately 300dpi.

30. A method according to any one of claims 25 to claim 29, wherein the image bearing portion is printed by a transfer printing process using sublimatic dyes.

31. A method according to any one of claims 25 to claim 30, wherein the image bearing portion is printed after it has been bonded to the backing layer.

32. A method according to any one of claims 25 to claim 31 , wherein the image bearing portion is covered after printing with a protective cover.