Abstract:
A substantially rectangular mat comprises an upper layer of fabric ( 31 ) bonded to a lower backing layer of natural or synthetic rubber ( 32 ). The lower backing layer ( 32 ) extends beyond the upper fabric layer to form a border strip ( 33 ) at first and second opposite edges ( 43,44 ) of the mat. The lower backing layer ( 32 ) ends flush with the upper fabric layer at third and fourth opposite edges ( 41,42 ) of the mat. Each of the third and fourth edges is provided with a moulded strip ( 15 ) of synthetic or natural rubber attached to the lower backing layer ( 32 ) to form a border strip.

Description:
TECHNICAL FIELD 
     This invention relates to a mat of the type where a natural or synthetic rubber backing sheet is secured to the back of a fabric layer leaving a rubber border extending beyond the fabric layer, and to a method of manufacturing such a mat. 
     BACKGROUND 
     It is well known to lay floor mats at the entrance of buildings such as dwellings and offices, for scraping and wiping the undersides of the footwear of persons entering the buildings. Scraper mats may also be employed for reducing levels of mud carried on footwear in locations such as building sites and farms. Such mats have a natural or synthetic rubber backing sheet to prevent the passage of dirt through the mat. The backing sheet extends beyond the fabric to form a border, which defines the edge of the mat. 
     It is known to provide such mats in the form of a continuous roll of matting, which may be cut to the required length to form a mat. The continuous roll of matting is provided with rubber borders at each longitudinal edge, formed by the backing sheet, which is wider than the mat fabric. When the mat is cut to length, the lateral edges have rubber borders, since they correspond to the longitudinal edges of the continuous roll. However the top and bottom cut edges do not have rubber borders, resulting in a mat which is not aesthetically pleasing. It is known to use extruded plastic edging strips at the top and bottom of the cut mat, but such edging strips do not match exactly the rubber borders at the lateral edges, and are not compatible with the mat, causing distortion and rippling. Furthermore, the mats are not launderable, because the plastic strips cannot withstand the heat of the laundering process. 
     SUMMARY 
     It is an object of the present invention to provide a mat which may be cut to length from a roll, but which is launderable and as aesthetically pleasing as a made-to-measure mat. 
     According to a first aspect of the present invention there is provided a substantially rectangular mat comprising an upper layer of fabric bonded to a lower backing layer of natural or synthetic rubber, whereby the lower backing layer extends beyond the upper fabric layer to form a border strip at first and second opposite edges of the mat, and whereby the lower backing layer ends flush with the upper fabric layer at third and fourth opposite edges of the mat, each of the third and fourth edges being provided with a moulded strip of synthetic or natural rubber attached to the lower backing layer to form a border strip. 
     Preferably, the moulded strip is attached to the lower backing layer by adhesive. 
     Preferably the moulded strip is formed such that the border strips at the third and fourth edges are of substantially the same appearance as the border strips at the first and second edges. 
     Preferably, the moulded strip includes a thin web portion that is secured beneath the backing layer and a thick web portion that abuts an edge of the backing layer. 
     According to a second aspect of the present invention, there is provided a method of making a mat comprising the steps of: 
     providing an elongate roll of mat material comprising an upper layer of fabric bonded to a lower backing layer of natural or synthetic rubber, whereby the lower backing layer extends beyond the upper fabric layer to form a border strip at the longitudinal edges of the elongate roll; 
     cutting transversely the elongate roll to form a portion of the elongate roll in which the lower backing layer extends beyond the upper fabric layer to form a border strip at first and second opposite edges of the mat, and in which the lower backing layer ends flush with the upper fabric layer at third and fourth opposite edges of the mat; 
     attaching a moulded strip of synthetic or natural rubber to the lower backing layer to form a border strip at the third and fourth opposite edges of the mat. 
     Preferably, the moulded strip is attached to the lower backing layer by adhesive. 
     Preferably, the moulded strip is formed such that the border strips at the third and fourth edges are of substantially the same appearance as the border strips at the first and second edges. 
     According to a third aspect of the present invention, there is provided a border strip for use in the method according to the second aspect of the invention, the border strip comprising an elongate member of natural or synthetic rubber of uniform cross-section, having a thick web portion and a thin web portion arranged adjacent to the thick web portion to form a generally L-shaped cross-section, the thin web portion being adapted to be secured beneath the backing layer of a mat in use, the thick web portion being adapted to abut the edge of a mat in use. 
     According to a fourth aspect of the present invention, there is provided a method of manufacturing a border strip according to the third aspect of the invention, the method comprising the steps of: 
     arranging first and second elongate mould plates in spaced apart relationship with a gap there between, said first mould plate having a cutting edge arranged adjacent to the gap, and said second mould plate being provided with a longitudinal channel in its upper surface extending parallel to and distal from the gap; 
     introducing fluid rubber into the mould such that the gap is filled with rubber and the rubber extends over the upper surface of the second mould plate and flows into the channel; 
     allowing the fluid rubber to cure to form a thick web in the gap, a thin web on the upper surface of the second mould plate, and a bead in the channel; and 
     removing the thick web and thin web from the mould and thereby separating the thin web from the bead in the channel. 
     Preferably, fluid rubber is introduced into the mould by placing a sheet of uncured rubber on top of the mould and heating the rubber in situ so that it flows into the mould. 
     Preferably, the rubber is heated in a heated press. 
     Preferably, the fluid rubber extends over the cutting edge of the first mould plate. Preferably, the excess rubber is removed from the surface of the first mould plate after curing by a cutting action of the cutting edge. 
     Preferably, the longitudinal channel has a narrow neck. Preferably, the separation of the thin web from the rubber bead is accomplished by the cutting action of a cutting edge provided at the neck of the channel. The thick web and thin web may be lifted from the mould and the separation accomplished by a tearing action. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Various embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
     FIG. 1 a  is a side elevation on a mould used to produce a moulded strip for use in a first embodiment of a mat in accordance with the invention; 
     FIG. 1 b  is a plan view on the mould of FIG. 1 a;    
     FIGS. 2 a  to  2   f  are side elevations on the mould of FIG. 1 a  during successive steps of the method of manufacture of a moulded strip for use in a mat in accordance with the invention; 
     FIG. 3 a  is a plan view on a mat in accordance with the invention before attachment of the moulded strip; 
     FIG. 3 b  is a side elevation on the mat of FIG. 3; 
     FIG. 4 a  is a plan view on a mat in accordance with the invention after attachment of the moulded strip; 
     FIG. 4 b  is a side elevation on the mat of FIG. 4 a ; and 
     FIG. 5 shows a roll of mat and a moulded strip used to make a mat according to the invention. 
    
    
     DETAILED DESCRIPTION 
     With reference to FIGS. 1 a  and  1   b  there is shown a mould for forming a border strip for use in making the mat of the present invention. The dimensions described as examples are not to be understood to be limiting to the invention. The mould comprises two elongate extruded metal plates  1 , 2  held together at a predetermined spacing (typically 20 mm) to form a gap  3  by joint pieces  4  which may be secured by any suitable means to the sides of the plates  1 , 2 . The metal plates  1 , 2  are sufficiently long to be able to form in one piece a moulded border strip long enough to extend across the entire width of a roll of mat. The first plate  1  is typically 40 mm wide and is provided with a cutting edge  5  adjacent to the gap  3 . The height of the cutting edge  5  from the underside of the first plate  1  is equal to the required thickness of the moulded border strip. The second plate  2  is provided with a longitudinal channel  6  typically at a distance of 40 mm from the gap  3 . The channel  6  has a narrow neck portion  7 , which has a cutting edge  8  at the side nearest the gap  3 . The height of the second plate  2  is less than the height of the cutting edge  6  of the first plate  1 , the difference in height being the thickness of the thin portion of the moulded border strip adapted to fit under the mat to which the strip is to be attached. Typically, this thickness is less than 1 mm, usually between 0.5 mm and 1 mm. 
     The method of forming a border strip is described with reference to FIGS. 2 a  to  2   f . The two plates  1 , 2  making up the mould are placed on a conveyor belt  10 , while a rubber piece  11  is introduced over the mould (see FIG. 2 a ). The conveyor belt conveys the mould and rubber along a press line, and the rubber  1  is pressed into the mould  1 , 2  while fluid, under the action of heating (see FIG. 2 b ). As the rubber  11  cures by the process of vulcanisation, the cutting edge  5  cuts and separates the rubber  11 , forming a straight edge  20  and allowing the surplus rubber  12  to be removed (see FIGS. 2 c  and  2   f ). This makes a separate trimming operation or further processing of the edge unnecessary. It is to be understood that although curing and/or vulcanisation has been described as the preferred process by which the rubber hardens or solidifies, other processes which cause the rubber to harden or solidify may be used. 
     The rubber is pressed into the channel  6  to form a bead  13 , which anchors any rubber  14  that flows beyond the channel  6  to the second plate  2 . When the rubber  11  forming the thick web and thin web has cured, it can be pulled away from the mould  1 , 2 , leaving the rubber bead  13  in the channel  6 . The cutting edge  8  ensures that the rubber in and beyond the channel  6  is readily separated from the rubber of the thin web, leaving a neat cut edge  21  (see FIGS. 2 d  and  2   e ). A separate trimming operation or further processing of the cut edge  21  is unnecessary. 
     The finished moulded border strip  15  is shown in FIG. 2 f  after removal from the mould. The border strip  15  is supplied in lengths equal to the overall width of the roll of mat with which the border strip is to be used. The border strip has a thick web  16 , which in use forms the visible border of the cut mat, and a thin web  17 , which in use is positioned beneath the rubber backing layer of the cut mat. The thick web typically has a thickness of between 1 mm and 3 mm, while the thin web typically has a thickness of between 0.5 mm and 1 mm. Of course variations in these dimensions are envisaged and fall within the scope of the invention. 
     FIG. 5 shows a border strip  15  and a roll of mat  30 . The mat  30  comprises a fabric layer  31  on a backing layer  32  of natural or synthetic rubber. The backing layer  32  is of overall width W and extends beyond the fabric upper layer  31  at both longitudinal edges of the mat  30  to form rubber borders  33 . 
     In use, the roll of mat is unrolled to the required length and cut transversely along cut line  40 , to form a mat  35  of the required size. After cutting, the cut edges  41 , 42  may be further trimmed if necessary to ensure that the edges are perfectly straight and square to the uncut edges  43 , 44 . 
     A moulded border strip  15  of length W is placed adjacent to the cut edge  41 , so that the backing layer  32  overlaps the thin web  17 , as shown in FIGS. 3 a  and  3   b . Adhesive  19  is applied to the top surface  18   b  of the thin web  17 , starting at one end of the border strip  15 , and the mat  35  is pressed onto the border strip to secure the border strip  15  to the mat  35 . If necessary the ends of the border strip may be trimmed to ensure a flush finish at the uncut edges  43 , 44 . The finished edge is shown in FIGS. 4 a  and  4   b.    
     If moulded nitrile rubber is used for the border strip and the backing layer, then a suitable adhesive is Loctite 4062J. This adhesive bonds rapidly and should be applied using dispensing needles in an AS@ pattern along the length of the thin web  17 . However, it is to be understood that other forms of adhesive may be used, such as glues or double sided tape. 
     A second moulded border strip  15  is attached to the other cut edge  42 , in the same manner, to complete the mat  35 . 
     The mat so formed has the appearance of a conventional, custom-made mat. If desired, the upper face  18   a  of the thick web  16  of the border strip  15  may be formed with a moulded pattern to match any pattern on the borders  33  of the rolled mat  30 . The resulting borders at the cut edge  41 , 42  are identical to the borders  33  at the side edges  43 , 44  formed during the manufacture of the rolled mat. This results in an aesthetically pleasing mat, which has the advantage of being launderable, if an adhesive is used which is resistant to high temperature laundering, such as Loctite 4062J. 
     The use of a rubber material for the border strips means that the material is compatible with the base layer material and borders of the rolled mat. 
     The method of the invention can be used to provide mats of the required length from a standard roll of matting. The method of the invention can also be used to repair a mat by cutting off a damaged edge and bonding a replacement moulded border strip to the cut edge of the mat. 
     The invention is not limited to the embodiments herein described but may vary in construction and detail.