The term"washable"means washable by immersion and agitation in water or other cleaning fluid usually followed by spin extraction and tumble drying. The term"mat" is used hereinafter in a wide sense to include rugs and carpets.

Manufacturers of washable rubber backed dust control mats sell their mats to the textile rental industry who then rent or sell the mats to the end users such as shops, factories, hospitals etc. The mats are placed at the entrances of buildings and serve to remove dirt and moisture from the feet of pedestrians entering the buildings. On a weekly, two weekly or monthly cycle the dirty mats are collected and returned to the laundry for washing and replaced with clean mats.

Such mats are frequently used to carry a message of one sort or another such as, for example, a company logo or trade mark. The message is normally created by forming the fabric layer from a mosaic of tufted fabric materials of different colours. The resulting mats are very smart in appearance, provide good dust control properties and are washable and hard wearing.

There can also sometimes be a need for a dust control mat that carries a temporary message such as, for example, an advertisement for a short-term sales promotion, or a sign of some sort, such as a direction sign or a welcome message. Although conventional dust control mats of the type described above could be used, they are generally rather expensive and long-lasting and using them for a temporary message would therefore be wasteful.

Another possibility is to use a cheaper printed mat. However, it is very difficult to produce a high definition printed image on a tufted mat, owing to movement of the pile during and after printing. Although a pile-less or very short pile mat could be used instead, such mats do not have good dust control properties. Further, such mats are often rather light and have a tendency to move (or"creep") when walked on.

This last problem is addressed in British patent No. 2083352 (Duskin), which describes a mat having a separate polyurethane base assembly in which the mat sits. The base assembly has a backing sheet and a raised frame that surrounds the edge of the mat, and a hook and loop anchoring system for retaining the mat in the base. The arrangement allows the mat to be removed for cleaning and ensures that it does not move in use. However, it does not address the problem of providing a mat that can carry a temporary message.

It is an object of the invention to provide a dust control mat that mitigates at least some of the disadvantages of the aforesaid mat types. In particular, but not exclusively, it is an object of the invention to provide a dust control mat that is capable of carrying a temporary message.

According to a first aspect of the present invention there is provided a floor mat assembly including a base portion having a polymeric backing layer and a fibre upper layer, and a removable insert having a polymeric backing layer and a fibre upper layer that fits into an aperture in the base portion. The insert may be removed and replaced easily with another insert carrying a different message. The base portion meanwhile continues to provide a dust control function. Because the whole mat does not have to be replaced, the message can be changed very economically.

In a first embodiment, the aperture extends through the base portion forming a window in the base portion. The aperture can be formed by, for example, die cutting. The piece that is cut out from the base portion can itself be used as an insert when no message is required, giving the appearance of a normal mat.

Advantageously, the assembly includes connecting means for retaining the insert in the aperture. The connecting means preferably includes a plurality of linking strips having hook and loop connectors. This allows the insert to be removed and replaced very easily. Preferably, the hook connectors are provided on the linking strips and the loop connectors are provided on the base portion and the insert. This avoids possible clogging of or damage to the hook connectors during laundering.

Advantageously, the backing layer extends inwards beyond the fabric layer, forming a border around the aperture. This forms a visual frame around the insert, providing an improved appearance. The backing layer of the base portion preferably increases in thickness towards the aperture, providing a reinforced edge.

In a second embodiment, the aperture extends through the fabric layer and includes a recess in the backing layer. The aperture does not extend completely through the base portion, but comprises a recesses in the upper face of the base portion, in which the insert is placed. The backing sheet extends over the whole of the rear surface of the base portion, providing increased dimensional stability and preventing outwards movement of the sides of the base portion that surround the aperture. The complete backing sheet also prevents dirt and dust from passing through the aperture onto the floor beneath.

Advantageously, the assembly includes connecting means for retaining the insert in the recess. This prevents movement of the insert in the recess. The retaining means preferably includes complementary linking formations in the recess and on the rear face of the insert. The linking formations may, for example, take the form of cleats.

Advantageously, the base portion includes a fabric layer of tufted pile fabric. This type of fabric has good dust control properties. Advantageously, the base portion includes a backing layer of natural or synthetic rubber, for example nitrile rubber.

Advantageously, the base portion is launderable.

Advantageously, the insert includes a fabric layer of knitted fabric. This type of fabric has good printing properties. It may also have good water absorbing properties. It may

also be relatively inexpensive. Advantageously, the fabric layer of the insert includes a printed image. Advantageously, the insert includes a backing layer of natural or synthetic rubber, for example nitrile rubber.

Advantageously, the assembly includes a plurality of alternative inserts. Preferably, at least one of said plurality of inserts includes a fabric layer of tufted pile fabric. This insert may be used when a message is not wanted, giving the assembly the appearance of a normal mat.

Embodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a first mat according to the invention; Fig. 2 is a side section through the first mat, on line II-II of Fig. 1; Fig. 3 is a side section through a second mat according to the invention; Fig. 4 is a side section through a press, showing the base portion of the second mat laid-up in the press, prior to the pressing operation; Fig. 5 is a side section through a third mat according to the invention; Fig. 6 is a plan view of a fourth mat according to the invention; Fig. 7 is a side section through the fourth mat, on line VII-VII of Fig. 6, and Fig. 8 is a side section through a press, showing the base portion of the fourth mat laid-up in the press, prior to the pressing operation.

The first mat shown in Figs. 1 and 2 has an outer or base portion 2 with a central rectangular aperture 4, and an inner portion or insert 6 that fits into the aperture.

The outer portion 2 includes a fabric layer 8 and a rubber backing layer 10. The fabric layer is slightly smaller than the backing layer 10, leaving an exposed frame 11 of rubber on the upper face of the mat around its periphery. The fabric layer 8 includes a tufted pile, which is tufted onto a substrate (or primary backing), for example of

woven or non-woven polyester or polypropylene of density between 70 and 300 gms/nr'. In the preferred example we use a non-woven polyester substrate of density 100 gms/nr'. The tufted pile can be cut, looped or both, and typically consists of cut pile.

The rubber backing layer 10 is made of nitrile rubber and advantageously has a thickness in the range 1. 5mm-5mm, preferably about 3mm. This is thicker than the backing normally provided on a conventional floor mat, and provides improved dimensional stability. The mat does not therefore shrink as much during laundering, which reduces the risk that the outer and inner portions 2,6 of the mat may eventually become incompatible in size.

The fabric layer 8 is bonded to the backing 10 of nitrile rubber in a heated press, for example at a temperature of 170°C and a pressure of 30 pounds per square inch, applied for a cycle time of twelve minutes.

The aperture 4 may be formed for example by die cutting. The inner portion removed after cutting may be used as an insert 6, simply by placing it in the aperture 4. In this case, the insert 6 will be identical in appearance to the outer portion 2, rendering the join between the two portions virtually invisible.

Alternatively, the insert 6 may be made of a different material, such as one that is cheaper and capable of supporting a high definition printed image. For example, the insert may include a fabric layer 12 of knitted polyester fabric and a rubber backing layer 13 that is bonded to the back of the fabric layer. The knitted fabric resists fraying, making it possible to produce a mat with cut edges and no rubber borders.

Manufacturing costs are therefore low. The fabric is absorbent, it wicks well, and is launderable, colourfast, durable and dimensionally stable. It prints well and provides for high resolution printing. Such a material is described in our British patent application No. 0019413. 4, the content of which is incorporated by reference.

Connecting means 14, for example as described in European Patent No. 0729311 (Berendsen), the content of which is incorporated by reference, may be provided for

securing the insert 6 in the aperture. Each connecting means 14 includes hook and loop type fastening materials and may, for example, consist of a strip 16 of hook material that engages pads 18 of complementary loop material, which are bonded to the lower faces of the outer mat portion 2 and the insert 6.

The connecting means 14 are releasable, allowing the insert 6 to be removed and replaced easily. The insert 6, which can carry a printed message, can therefore be replaced whenever a different message is required. Because the inserts are relatively cheap, they are suitable for displaying temporary messages, and can be disposed of when no longer required. The outer portion 2 of the mat meanwhile continues to provide a dust control function, while also serving to support the insert and retain it in the desired position.

A second mat according to the invention is shown in cross section in Figure 3. The mat includes an outer or base portion 22 with a central rectangular recess 24, and an inner portion or insert 26 that fits into the recess.

The outer portion 22 is similar in most respects to that of the first mat described above and includes a fabric layer 28 and a rubber backing layer 30. The recess 24 does not extend completely through the base portion 22 and instead the rubber backing layer 30 includes an outer portion 32 of larger than normal thickness and a rectangular inner portion 34 of reduced thickness, which forms the recess 24. The fabric layer 28 covers only the outer portion 32 of the rubber backing layer and is slightly smaller than that layer, leaving an exposed frame 36 of rubber on the upper face of the mat around its periphery. The fabric layer 28 includes a tufted pile, which is tufted onto a substrate (or primary backing), for example of woven or non-woven polyester or polypropylene.

The insert 26 sits in the recess 24 formed by the thinner inner portion 34 of the rubber backing layer 30. The insert 26 is preferably made of a material that is capable of supporting a high definition printed image. For example, the insert may include a fabric layer 37 of knitted polyester fabric and a rubber backing layer 38 that is bonded to the back of the fabric layer. Alternatively, the insert 26 may have a tufted fabric layer.

A process for making the second mat will now be described with reference to figure 4, which is a schematic exploded cross-section of the mat as laid up in a press during manufacture. The press includes a heated metal platen 40, above which there is an inflatable diaphragm 42, mounted on a frame 43. The frame 43 may be either fixed or moveable, depending on whether the press has a fixed or variable opening aperture.

The lay up consists of the following items placed in order on the heated platen 40: a bottom release sheet 44, a 3mm thick sheet of uncured rubber 46, a 2.5mm thick metal moulding plate 48, a die cut fabric sheet 50 and a top release sheet 52.

The release sheets 44,52, which are made of PTFE-coated woven glass fabric, cover the laid up mat to prevent the rubber sheet 46 sticking to the heated platen 40 and the diaphragm 42. They also impart a woven fabric imprint to the exposed surfaces of that sheet for improved aesthetic appearance.

The metal moulding sheet 48, which is rectangular and made of 3mm aluminium sheet, is placed on the centre of the rubber sheet 46 to mould the recess 24 in the backing layer 30.

The fabric sheet 50 is rectangular and has a central rectangular aperture 54, the same size and shape as the metal moulding sheet 48. The fabric layer thus fits around the edge of the moulding sheet 48 when they are laid on the rubber sheet 46. The fabric sheet preferably consists of a tufted cut or looped pile of woven or non-woven polyester or polypropylene, tufted onto a non-woven polyester substrate.

The press is heated to a temperature of about 170°C. The laid up mat is positioned between the platen 40 and the diaphragm 42, for example on a conveyor belt or tray, and the diaphragm 42 is then inflated, for example to a pressure of 30 pounds per square inch, pressing the laid up mat against the heated platen 40, typically for a cycle time of twelve minutes.

The heat from the platen 40 softens and cures the rubber sheet 46 and the pressure from the diaphragm 42 presses the fabric sheet 50 into the rubber, bonding the two sheets together. At the same time, the metal moulding sheet 48 is pressed into the centre of the

rubber sheet 46, forming the recess 24. The rubber beneath the moulding sheet 48 flows outwards, increasing the thickness of the backing layer 30 around the periphery of the recess 24. The release sheets 44,52 impress a surface texture into the exposed surface of the rubber sheet 46.

After completion of the pressing process, the diaphragm 42 is deflated and the rubber backed mat is removed from the press and allowed to cool. The release sheets and the moulding sheet are then removed. If necessary, the edges of the rubber backing layer 30 may be trimmed, for example using a guillotine. Typically, in a finished mat, the thickness of the rubber backing layer 30 is about 1.5mm in the recess and 4.0mm around the periphery of the recess, decreasing gradually to about 3mm at the outer periphery of the outer portion 22.

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 fabric sheet below the rubber sheet, and the cycle time is increased to approximately twenty-nine minutes. The process for making the mat is otherwise substantially as described above.

The mat may include means for retaining the insert 26 in the recess 24. This may be important to prevent sideways movement of the insert or lifting of its edges and corners. For example, hook and loop materials may be used, preferably with the hook material attached to the disposable insert and the loop material attached to the launderable base portion of the mat. This is the preferred arrangement, as it avoids using hook material on laundered products, since the hooks can cause snagging and tend to become clogged with fibres, reducing their effectiveness. Alternatively, the insert may be retained in position with a releasable adhesive or with two-sided adhesive tape or sheet material.

An alternative method of retaining the insert in position is illustrated in figure 5. In this arrangement, rubber cleats 60 are provided on the underside of the insert 26 and the upper surface of the recess 24. The cleats 60 interlock, preventing movement of the insert. The cleats in the recess 24 may be formed during the pressing process by

providing small holes in the metal moulding sheet 48, into which the molten rubber flows as it is heated in the press. Similarly, the cleats on the underside of the insert 26 may be formed during the pressing stage of the process for manufacturing the insert, in which the fabric layer is bonded to a rubber backing layer. Again, a moulding sheet having a plurality of small holes is used, which is placed underneath the rubber backing layer during pressing, so that the cleats are formed as molten rubber flows into those holes.

A fourth mat according to the invention is shown in figures 6 and 7. This mat is similar in most respects to the first mat shown in figures 1 and 2, the main difference being that an exposed rubber border or frame 70 is provided around the edges of the aperture 74 in the outer or base portion 72 of the mat. As in the first mat, the outer portion 72 includes a fabric layer 78 and a rubber backing layer 80. The fabric layer is slightly smaller than the backing layer 80, leaving an exposed frame 82 of rubber on the upper face of the mat around its periphery. The fabric layer 72 includes a tufted pile, which is tufted onto a substrate of woven or non-woven polyester or polypropylene.

The insert 76 may for example include a fabric layer 37 of knitted polyester fabric and a rubber backing layer 38 that is bonded to the back of the fabric layer. Connecting means 14 similar to the hook and loop connectors shown in figure 1 may be provided for securing the insert 76 in the aperture 74.

A process for making the fourth mat will now be described with reference to figure 8, which is a schematic exploded cross-section of the mat as laid up in a press during manufacture. The press includes a heated metal platen 90, above which there is an inflatable diaphragm 92, mounted on a frame 93. The frame 93 may be either fixed or moveable, depending on whether the press has a fixed or variable opening aperture.

The lay up consists of the following items placed in order on the heated platen 90: a bottom release sheet 94, an edge forming frame 96, a sheet of uncured rubber 98, a die cut fabric sheet 100 and a top release sheet 102.

The fabric sheet 100 is rectangular and has a central rectangular aperture 104. The fabric sheet preferably consists of a tufted cut or looped pile of woven or non-woven polyester or polypropylene, which is tufted onto a non-woven polyester substrate.

The edge forming frame 96 is rectangular and has a raised cutting edge 106 around its outer periphery, which cuts through the rubber sheet 98 during the pressing process to form the central aperture 74 in the backing layer 80. The frame may be made of aluminium and may be substantially as described in our European patent application No. 96928592.3, publication No. 0847327, the content of which is incorporated by reference herein.

The press is heated to a temperature of about 170°C. The laid up mat is positioned between the platen 90 and the diaphragm 92, for example on a conveyor belt or tray, and the diaphragm 42 is then inflated, for example to a pressure of 30 pounds per square inch, pressing the laid up mat against the heated platen 90, typically for a cycle time of twelve minutes.

The heat from the platen 90 softens and cures the rubber sheet 98 and the pressure from the diaphragm 92 presses the fabric sheet 100 into the rubber, bonding the two sheets together. At the same time, the edge forming frame 96 is pressed upwards through the centre of the rubber sheet 98, forming the aperture 74. The frame also tends to cause a thickening of the rubber at those edges, thereby reinforcing the edges as described in EP 0847327. The release sheets 94,102 impress a surface texture into the exposed surfaces of the rubber sheet 98.

After completion of the pressing process, the diaphragm 92 is deflated and the rubber backed mat is then removed from the press and allowed to cool. The release sheets and the moulding sheet are then removed. If necessary, the edges of the rubber backing layer 80 may be trimmed, for example using a guillotine. Alternatively, a second edge forming frame may be used during the pressing process to form the outer periphery of the rubber backing sheet.

Various modifications of the mat assembly are of course possible, some of which will now be described.

The aperture in the base portion need not be rectangular but may have any shape. In particular, instead of square corners the corers may be rounded, thereby reducing the risk of tearing, particularly during laundering. The external shape of the base portion may also be modified, for example it may be rectangular, square, circular or oval.

The insert may be retained in position in the recess by various means, including one or more of the following: using hook and loop connectors (of the type sold under the trade mark VELCRO), with patches of loop material moulded to the underside of the base portion and the insert and patches of hook material on linking plates; using patches of hook material fixed either to the floor beneath the aperture in the base portion or to the recess in the base portion, and patches of loop material moulded to the underside of the insert; using metallised rubber (containing ferrous oxide) for the backing layer, and fixing magnetic strips in the recess in the base portion or to the floor beneath the aperture; providing an adhesive layer, for example a piece of felt coated with a tacky rubber polymer as sold under the trade mark ANCHORGRIP, in the recess, or moulding interlocking cleats in the recess and on the underside of the insert.