GB2284151A - Floor covering with spaced tread strips of layered felt - Google Patents

Abstract

A floor covering suitable as an entrance mat comprises a plurality of tread strips (11) of substantially resilient and flexible material, a plurality of spacer strips (12) of substantially rigid material arranged interposed between the tread strips and the pluralities of strips being secured together in side by side relationship by connecting means (14) which pass through the strips, each tread strip (11) comprises an assembly of at least a first wear layer (15) of wear resisting felt material to provide a fibrous tread surface and a second support layer (16) of a relatively lower cost felt material, the first and second layers (15, 16) of felt being secured together and arranged to lie in planes parallel with the tread surface of the floor covering, and the first layer (15) of each strip (11) being arranged to lie at least in part above the spacer strips (12) thereby to provide the tread surface with recess regions between successive pairs of tread strips. <IMAGE>

Description

"FIDOR COVERINGS" This invention relates to a floor covering suitable for use as an entrance mat and to a method of manufacture of said floor covering.

A floor covering for use as an entrance mat needs a heavily textured upwardly facing surface having wiper regions to remade dirt and moisture from footwear and recess regions to receive collected dirt pending periodic cleaning. One such type of floor covering in the form of an entrance mat is described in our Patent Specification A-2258624A. The mat comprises a plurality of first strips of substantially rigid material, for example of aluminium or a plastics material such as polyvinyl chloride or polypropylene, and a plurality of second strips of substantially resilient and flexible material such as natural or synthetic rubber which support a fibrous tread surface, the second strips being interposed alternatively between the first strips and the first and second strips being secured together in side-by-side relationship by means of one or morse connecting elements, such as wires, which pass through aligned apertures in the first and second strips.

In the aforedescribed construction the fibrous tread surfaces of the second strips serve primarily as wiper regions to support footwear passing thereover and perform a cleaning action whereas the recess regions provided by the first strips between respective neighbouring pairs of second strips serve as collector grooves in which dirt may gather for subsequent removal during a mat cleaning operation.

Commanly the first, substantially rigid, strips are of an H-shape in cross-section with the cross piece of the H, in use, lying vertically in the direction of the thickness of the matting. Said cross piece is provided with apertures through which the connecting elements pass, and the edges of the side pieces of the H formation abut adjacent flexible second strips.

Alternatively they are ccamronly of half an H shape, i.e. a C type shape.

Conventionally each said second strip has an embedded reinforcement of one or more layers of fabric arranged to lie substantially transverse to the plane of the mat and the surface of the rubber or like substantially resilient material is ressved from a face of the strip which is to define the tread surface so as to expose the fibres and provide a fibrous tread surface. The embedded reinforcerent provides the strip with a good degree of stiffness so that it resists deformation when subject to load.

The resulting mat with a fibrous tread surface as described in the preceding paragraph is found to exhibit excellent wear characteristics even in conditions of arduous use, and to remain effective in providing a cleaning action. However the mat is labour intensive in manufacture.

The construction of the said second strips of embedded reinforcement contributes to excellent wear characteristics, but that material is expsive.

An object of the present invention is to provide a floor covering which is relatively economical to construct and is relatively econanical in use of materials, In one of its aspects the present invention provides a floor cavering coqprism g a plurality of tread strips of substantially resilient and flexible material, each of said tread strips having a wear layer of fibrous or fibrous like material whereby said tread strips provide a fibrous tread surface, a plurality of spacer strips of substantially rigid material arranged interposed between the tread strips whereby each successive pair of tread strips is spaced apart by at least one spacer strip and the pluralities of strips being secured together in side by side relationship by connecting means which pass through aligned apertures in the strips, each tread strip cattprising an assembly of at least a first wear layer of wear resisting felt material and a second support layer of a relatively lower cost felt material, the first and second layers of felt being secured together and arranged to lie in planes parallel with the tread surface of the floor covering, and the first layer of each strip being arranged to lie at least in part above the spacer strips thereby to provide the tread surface with recess regions between successive pairs of tread strips.

The term felt is used herein to refer to a material characterised by a densely matted condition of nost or all of the fibres of which it is composed. It may be a material having a woven or knitted fabric structure.

It may be a material which relies for its construction on the ability of the constituent fibres to mat together to form a composite body with neither warp nor weft. It may be a needle felt produced by a needleloan process.

One or each of the first and second layers of a tread strip may be of needlepunched material. The layers may be secured together by needle punching or by the use of an adhesive such as latex. Preferably the layers are interconnected by means which does not form an impermeahle barrier therebetween.

A tread strip may comprise only a single, first wear layer and a single, second support layer. Preferably it is of a sandwich construction comprising two first wear layers having a support layer sandwiched therebetween. Provision of a sandwich constuttion in which two wear layers lie at opposite, outermost positions of the sandwich is advantageous in allowing provision of a mat or like floor covering which is reversible.

An example of a suitable felt material for a first, wear layer of a tread strip is polypropylene. This may be provided in needle punched form.

An example of a suitable felt material for a second, support layer of a tread strip is a felt formed fram reconstituted waste material. The felt of the second, support layer may be of a material of a relatively lower cost than the material of a first felt layer.

A wear layer may have a resiliency which is either greater or lower than that of the associated support layer.

A wear layer may have a compression resistance which is either greater or lower than that of the associated support layer.

The compression stress strain of the support layer may be greater than and preferably is at least twice that of the wear layer. The or a wear layer may have a ccttpression stress strain in the range 0.02 to 0.10, preferably in the order of 0.04, when measured as the stress at 20% compression during compression of the material at a speed of 10 ztrn per minute. The support layer may have a ccpnpression stress strain i the range 0.10 to 0.30, preferably in the order of 0.22, when measured in the samr m2nner. (Relevant units are MPa).

The compression set of the wear layer may be greater than, and preferably is at least twice, that of the support layer. The or a wear layer may have a compression set in the range 60% to 95% when measured in general accordance with BS 903 Part A6 but using rectangular section test pieces 30 mm long cut fran strips of the material and with cottpression conditions of 2 weeks at 400 and 25% cottpression. The support layer may have a compression set in the range 15% to 60% when measured in the saze manner. Preferably the or a wear layer has a compression set in the order of 85% and the support layer has a compression set in the order of 30%.

A wear layer preferably has a density in the range 0.15 to 0.40 g/cc, more preferably in the range 0.22 to 0.34 g/cc.

A support layer preferably has a density in the range 0.20 to 0.45 g/cc more preferably in the range 0.27 to 0.38 g/oc.

Other preferred properties of a wear layer and a support layer are that it is able to absorb moisture and readily allow evaporation of accumulated moisture.

The support and wear layers may be of materials selected to have water absorption properties of at least 150%, mDre preferably in the order of 200%, and an evaporation of in the order of -1.08. These percentages are determined by immersing samples of the materials in water at 230C for 24 hours, remaking and allowing to dry in an air stream fran a fan of 1.5 to 2 m/s and reweighing after 3 hours, the evaporation percentage result being given as the remaining absorption.

A wear layer preferably has a thickness of less than 30% of the total thickness of a tread strip. In a sandwich construction in which a support layer lies between a pair of wear layers, the support layer preferably has a thickness of at least 40% and more preferably at least 50% of the strip thickness. In a sandwich construction it is preferred that the two outer wear layers are of equal thickness.

A spacer strip may be of the aforedescribed H or C cross-ses-tional shape, or of another rigid and hollow or solid form.

An example of an alternative spacer strip construction is one comprising a pair of longitudinally extending and co-planar abutment faces for bearing against and providing lateral support to a side face of a tread strip. The maximum spacing of extreme edges of the abutment faces as viewed in cross-section is selected to be less than the height of the side face of an adjacent tread strip whereby said spacer strip provides a recess region between a successive pair of tread strips. The e spacer strips may be of a hollow, e.g. tubular, shape as considered in cross-section, and in that case the pair of abutment faces of a strip may be separated by a longitudinally extending slit. That slit may be dimensioned and positioned to allow the connecting IIleans to extend therethrough. Alternatively the abutment faces may, for example, be contiguous, with apertures being provided for the connecting means.

The abutrwzt faces, as viewed in transverse cross-section of a spacer strip, preferably each have a length of at least 15% and more preferably at least 25% of the height of the side face of a tread strip. The abutment faces are able thereby to provide useful lateral support to the relatively substantially resilient and flexible strips.

The e spacer strips preferably have substantially planar distance faces which are parallel with and spaced from the associated abutment faces. Two spacer strips may be provided between a pair of tread strips and the distance face of one strip may be arranged to contact the distance face of another spacer strip of the pair or another spacer element interposed between the pair of spacer strips. The distance faces preferably are provided with apertures through which the connecting means may extend.

It is preferred also that the spacer strips each comprise a side face which lies inclined relative to the abutment, preferably orientated such that the thickness of the spacer strip reduces, as considered in crosssection, witch increasing distance fran its abutment faces. That side face preferably is one that faces generally upwardly in use of the floor covering; the spacer strip may have two inclined side faces so that the floor covering is fully reversible in use. Preferably the spacer strip is of trapezoidal cross - sectional shape.

Two spacer strips may be arranged directly in contact with one another between a pair of tread strips. They may have planar distance faces spaced fran the pairs of abutment faces and may have said spacing determnrng distance faces directly in contact. Alternatively auxiliary spacer Itans may be provided between a pair of tread strips.

The auxiliary spacer means may be longitudinally continuous and be shaped for longitudnally continuous contact with the distance faces. The auxiliary spacer means alternatively may be profiled along its length or may comprise a plurality of discrete spacer elements whereby the floor covering is provided with openings through which dirt or water may pass.

If the auxiliary spacer means comprises discrete spacer elements, said elements may be apertured for location on and support by the connecting neans of the floor covering.

The auxiliary spacer means as viewed in cross-section of the floor covering, preferably has a height in the range 40% to 90%, mare preferably 50% to 75%, of the height of neighbouring tread strips.

The pairs of abutment faces of a spacer strip preferably are arranged to lie in contact predominantly with the support layer and no more than a part of the wear layer(s) of the tread strip of felt material.

The connecting means may be arranged to maintain the tread strips under residual compression in a transverse direction in which the connecting means extend through the strips. It is believed that this will assist in maintaining the flexibility and resiliency properties of wear strips by resisting any tendency for them to spread sideways and flatten in use.

Emtodiment of the present invention will now be described, by way of example, with reference to the drawings in which: Figure 1 is a plan view of an entrance mat of the invention; Figure 2 shows part of Figure 1 in greater detail; Figure 3 is an end view of Figure 2; Figure 4 is a perspective view of part of a tread strip of the mat of Figures 1 to 3, and Figures 5 and 6 are plan and end views of a mat in accordance with another esbodiment.

A floor covering for use as an entrance mat 10 comprises a plurality of relatively substantially resilient and flexible tread strips 11 and a plurality of relatively substantially rigid spacer strips 12 arranged with neighbouring pairs of tread strips each spaced by a spacer strip. The assembly of strips 11,12 is held together against transverse separation by transversely extending high tensile steel connecting wires 14.

Each tread strip 11 is a sandwich of three layers of felt. Each strip has two outer, wear layers 15 (see Figure 3) of polypropylene and a central support layer 16 of reconstructed waste or other low cost material in a felt form. The three layers of felt are united by needle punching. The central layer is pierced at intervals along its length to provide apertures 17 which extend transversely of the strip (see Figure 4), in a direction parallel with the planes of the wear layers 15, for passage of the connecting wires through the strip.

The upper and lower outer wear layers 15 each have a thickness of approEimately 25% of the thickness, i.e. height, of the strip as viewed in Figure 3. Thus the layer 16 has a thickness of approximately 50% of the total thickness.

Properties of the two wear layers (15) and of the support layer (16) of the tread strip 11 of this embodinEst are: PraDertv Wear layer Support layer Composite (15) (16) strit(11) Compression stress strain stress at 20% MPa 0.04 0.22 0.36 Compression set.% 85.0 30.0 85.4 Density g/cc 0.28 0.33 Water absorption % 200 180 Evaporation % -1.0 -1.1 Each spacer strip 12 is H shaped in cross-section with the cross-piece of the H lying vertically, i.e. transverse to the plane of the mat. The four abutment edges 20 of each spacer strip each contact a felt tread strip in the region of an interface between an outer wear layer 15 and a central support layer 16. Thus each edge 20 partly abuts a wear layer and partly abuts a central support layer.

Outer edges of the mat are defined by a pair of flanged C section strips 30 apertured to receive the connecting wires 14 and each having a longitudinal slit 31 to allow the hollow cavity 32 of the strip to accommodate a bent portion of wire 14.

The e wires 14 are bent whilst the assembly of spacer and tread strips 12,11 is compressed transversely in a jig. On completion the wires serve to hold the felt tread strips in residual transverse catpression.

In an alternative construction (see Figures 5 and 6) the H section spacer strips are replaced by pairs of the aforedescribed flanged C section strips 30 arranged with the flanges 33 to act as abutment faces to contact side faces of the tread strips.

The two spacer strips 30 are separated by spacer discs 34 supported by the connecting wires thereby to provide the mat with an array of openings.

Claims (35)

CLAIMS;

1. A floor covering ccanprising a plurality of tread strips of substantially resilient and flexible material, each of said tread strips having a wear layer of a material which provides a fibrous tread surface, a plurality of spacer strips of substantially rigid material arranged interposed between the tread strips whereby each successive pair of tread strips is spaced apart by at least one spacer strip and the pluralities of strips being secured together in side by side relationship by connecting means which pass through the strips, each tread strip comprising an assembly of at least a first wear layer of wear resisting felt material and a second support layer of a relatively lower cost felt material, the first and second layers of felt being secured together and arranged to lie in planes parallel with the tread surface of the floor covering, and the first layer of each strip being arranged to lie at least in part above the spacer strips thereby to provide the tread surface with recess regions between successive pairs of tread strips.

2. A floor covering in accordance with claim 1, wherein the first and second layers of a tread strip are interconnected by means which does not form an impermeable barrier therebetween.

3. A floor covering in accordance with claim 1 or claim 2, wherein at least one of the first and second layers of a tread strip is of needle punched material.

4. A floor covering in accordance with any one of the preceding claims, wherein the first and second layers of a tread strip are secured together by needle punching.

5. A floor covering in accordance with any one of the preceding claims, wherein a tread strip is of a sandwich construction comprising two first wear layers having a support layer sandwiched therebetween.

6. A floor covering in accordance with any one of the preceding claims, wherein the felt material is a material having a woven or knitted fabric structure.

7. A floor covering in accordance with any one of claims 1 to 5, wherein the felt material comprises constituent fibres matted together to form a composite body which is bereft of warp and weft coNponents.

8. A floor covering in accordance with claim 7, wherein the felt material is a needle felt produced by a needle loan process.

9. A floor covering in accordance with any one of the preceding claims, wherein a tread strip wear layer has a thickness of less than 30% of the total thickness of the tread strip.

10. A floor covering in accordance with claim 9, wherein in a tread strip comprising a support layer sandwiched between a pair of wear layers the support layer has a thickness of at least 40% of the tread strip thickness.

11. A floor covering in accordance with claim 10, wherein the support layer has a thickness at least 50% of the strip thickness.

12. A floor covering in accordance with claim 10 or claim 11, wherein the two outer wear layers are of equal thickness.

13. A floor covering in accordance with any one of the preceding claims, wherein the felt material of a wear layer is polypropylene.

14. A floor covering in accordance with any one of the preceding claims, wherein the felt material of a support layer is a felt formed fran reconstituted waste material.

15. A floor covering in accordance with any one of the preceding claims, wherein the ccrmpression stress strain of the support layer of a tread strip is greater than that of the wear layer of that strip.

16. A floor covering in accordance with claim 15, wherein the support layer has a compression stress strain at least twice that of the wear layer.

17. A floor covering in accordance with claim 15 or claim 16, wherein the wear layer has a compression stress strain in the range 0.02 to 0.10 when measured as herein described.

18. A floor covering in accordance with any one of the preceding claims, wherein the compression set of the wear layer of a tread strip is greater than that of the support layer of that strip.

19. A floor covering in accordance with claim 18, wherein the wear layer has a compression set in the range 60% to 95% when measured as herein defined.

20. A floor covering in accordance with any one of the preceding claims, wherein the support layer of a tread strip has a compression set in the range 15% to 60% when measured as herein defined.

21. A floor covering in accordance with any one of the preceding claims, wherein the wear layer of a tread strip has a density in the range 0.15 to 0.40 g/cc.

22. A floor covering in accordance with any one of the preceding claims, wherein the support layer has a density in the range 0.20 to 0.45 g/cc.

23. A floor covering in accordance with any of the the preceding claims wherein the connecting means maintains the tread strips under residual carpression in a transverse direction in which said means extend through the strips.

24. A floor covering in accordance with any one of the preceding claims, wherein a spacer strip comprises a pair of longitudinally extending and co-planar abutment faces for bearing against and providing lateral support to a side face of a tread strip.

25. A floor covering in accordance with claim 24, wherein the nEaumlm spacing of extreme edges of the pair of abutment faces as viewed in cross-section is less than the height of the side face of an adjacent tread strip whereby said spacer strip provides a recess region between a successive pair of tread strips.

26. A floor covering in accordance with claim 24 or claim 25, wherein the spacer strip is of a hollow construction and said pair of abutment faces are separated by a longitudinally extending slit through which the connecting means extend.

27. A floor covering in accordance with any one of claims 24 to 26, wherein said abutment faces, as viewed in transverse cross-section of the spacer strip, each have a length of at least 15% of the height of the side face of a tread strip.

28. A floor covering in accordance with claim 27, wherein said length is at least 25% of the height of the side face.

29. A floor covering in accordance with any one of claims 24 to 28, wherein the spacer strip has a substantially plaaar distance face which is parallel with and spaced fran the abutment faces of that strip.

30. A floor covering in accordance with claim 29, wherein two of said spacer strips are provided between a pair of tread strips and are arranged with their respective distance faces in contact.

31. A floor covering in accordance with claim 29, wherein two of said spacer strips are provided between a pair of tread strips and are arranged with their respective distance faces spaced by spacer means interposed between said faces.

32. A floor covering in accordance with claim 31, wherein said spacer means is longitudinally discontinuous.

33. A floor covering in accordance with any one of claims 24 to 32, wherein the pair of abutment faces of the spacer strip lie in contact predcaninantly with the support layer and no more than a part of the wear layer(s) of the adjacent tread strip.

34, A floor covering in accordance with any one of the preceding claims, wherein a spacer strip comprises a side face inclined relative to the surface of the floor covering.

35. A floor covering in accordance with claim 1, and substantially as described herein with reference to and as shown in the accompanying Drawings.