IE44155B1 - Improvements in and relating to the backing of carpets - Google Patents

Abstract

A tufted carpet or similar non-woven floor covering has a pile surface carried by a primary backing, an anchor coat to bind the pile into the backing, a resilient layer of foam laminated to the anchor coat and an at least partly fibrous secondary backing laminated to the foam. The thickness of the foam is in the range of 1.0 to 4.0 millimetres and the secondary backing is preferably laminated directly to the layer of foam. The main constituent of the foam may be styrene butadiene rubber and the foam may be extruded by a filler or fillers. The floor covering is produced by a method which includes the step of bringing the layer of foam and the secondary backing into contact with one another while the foam is still in a moist state so as to cause a degree of mutual penetration between these two layers and then completing the lamination by the application of heat to cure and dry the foam.

Description

- This invention relates generally to non-woven floor coverings having a pile surface carried by a primary backing. It is particularly· ' ’ : concerned with tufted carpets and for simplicity will be described • . in terms of such carpets without prejudice to its more general 5application.

' In the finishing of tufted carpets, a foam backing which may be of 2.5 to 6 millimetres in thickness is normally applied. This renders the look of the completed carpet noticeably different from that of a woven carpet, and a certain degree of sales resistance /10 to the appearance of a foam-backed tufted carpet still remains.

The interlocking structure of a woven carpet, e.g. of the Axminister or Wilton type, Where the pile yarn is incorporated by the weaving together ofthe backing yarns needs only the application ’ of a starch or latex in a simple finishing process to give the carpet a good finish and handle. On the other hand, tufted carpet , .-- requires greater attention in finishing if an acceptable produce is ; ·. to result. As mentioned above, a foam-backed carpet is generally regarded as inferior, but the alternatives to this which have so far been adopted lead to no real improvement. Thus a latex or similar substance which may be applied to anchor the tufts into the primary backing does little to improve,the handle and,dimensional - stability of the carpet. In a subsequent stage in finishing, therefore, a secondary backing, which may be of woven or non-woven material and in which jute and/or polypropylene in various forms are commonly present, is sometimes laminated to the latexed, partially finished carpet as a substitute for a foam backing. This serves to improve dimensional stability, appearance and handle, but, particularly with relatively low pile weights, the addition of the secondary backing results in a carpet which, by comparison with woven carpet, still remains light and flimsy and thus lacking in bulk and therefore apparent value.

According to the present invention a woven or non-woven secondary backing is applied in addition to and externally of a foam layer, that is to say with the outer surface of the secondary backing lying wholly outside that of the layer. This leads to the double advantage of rendering the foam layer with its connotations of inferiority effectively invisible, i.e. by ensuring that no foam is present at the outermost surface of the backing, to give an appearance similar to that of a woven carpet and, as a result of the additional layer, considerably increased firmness, dimensional stability, bulk resiliency and handle.

Expressed in more specific terms, a tufted carpet or other non-woven floor covering in accordance with the invention has a pile surface carried by a primary backing, an anchor coat to bind the pile into the backing, a resilient layer of foam laminated to the anchor coat and a woven or non-woven secondary backing which is preferably at least partially fibrous, laminated directly to the foam so that it outer surface lies wholly outside that of the foam.

The main advantages of such a structure as mentioned above are particularly applicable to tufted carpets and other non-woven floor 44155 coverings having comparatively low pile weights, giving them improved performance and wider sales appeal. There is also the additional advantage of not requiring a separate underlay when the carpet is fitted in position, although an underlay may be used if required. , For best results, the thickness of the layer of foam should be in the range of 1.0 to 4.0 millimetres, the thickness within this range being dependent on the properties and effect required and the characteristics of the other components of the carpet.

Generally speaking, best results are achieved for a thickness between TO 1.5 and 2.0 millimetres. For a thickness less than 1 millimetre, little advantage is gained from the additional complication of including the foam and for thicknesses greater than 4.0 millimetres, the additional advantage is not communsurate with the added cost.

Whatever its thickness, the foam may be pigmented to the colour of the secondary backing to assist in the visual simulation of a woven carpet, since although there must be no foam at the outer surface of the secondary backing, minute areas of foam may be visible through the interstices of the secondary backing.

The direct lamination of the secondary backing to the layer of foam 2Q can be achieved as a result of a direct bond between the two resulting from bringing the two layers into contact with one another without the application of external pressure while the layer of foam is still in a moist condition so as to cause a degree of mutual penetration between , the two layers. The bond between the two is then completed by the application of heat to cure and dry the foam. The mutual penetration is facilitated when the secondary backing is of an at least partly fibrous nature so that the foam can penetrate between the fibres and, to a certain extent, any projecting fibres can extend into the foam. As has been made clear previously, any penetration of the foam between the fibres must be only partial so that the presence of foam at the outer surface of the secondary 44135 backing, known as 'strike-through' is positively avoided. The resultant direct bond leads to a basic laminated structure comprising just four layers, i.e. the pile-carrying primary backing, the anchor coat, the foam layer and the secondary backing.

Apart from its thickness discussed above, the nature of the foam used is of major importance in obtaining the required properties of resilience. Generally speaking, the foam should comprise a rubber or a rubberlike material and best results are obtained when the foam is latex-based. Apart from providing the rubber-like features within the foam, the use of a latex-based material provides adhesive properties and moreover for purposes of economy the latex can be extended by the use of fillers. The best of the latex-based materials are in the form of synthetic rubbers, of which that preferred is styrene-butadiene rubber, the styrene content being of significance in providing the desired properties referred to above.

The foam used may be either of the gel or no-gel type, either synthetic or natural, the only important difference between the two lying in the processing rather than in the final properties. The curing of a nogel foam is in effect a drying process, for the cured foam structure is not wholly present until the foam is dried. Expansion takes place as air passes through the cellular structure during the drying process. The curing of a gel foam on the other hand, is a vulcanising process and the foam thickness is reduced during the process. 4415S • * ................ · - .....· “t f ; The basic cu^fig treMnent for both types of foam is tbe same, however, involving preliminary drying, e.g. by means of infra-red radiation, followed by curing in an oven. For tbe reason just explained, a no-gel foam , will expand between 10 and 20% during curing. Therefore, in order to achieve a cured thickness of 1.5 millimetres, a gel foam will need to be applied in thicknesses of approximately 1.65 to 1.80 millimetres and a no-gel foam will be applied in thicknesses of approximately . 1.25 to 1.375 millimetres.

Only a thin layer of the anchor coat is required and in order to increase its volume at the time of application and thus to assist in even application, the anchor coat is also preferably in the · form of a foam which collapses as it is dried so that, in the finished carpet, the anchor coat is present in the form of a collapsed foam. As with, the foam layer, the anchor coat is preferably latex-based and may be a carboxylated latex. As with the main foam layer, the .20. preferred material is a styrene butadiene latex.

As previously mentioned, the secondary backing is preferably an at least partly fibrous material which is preferably-woven although non-woven materials are also suitable. If a woven fabric is used, it is important that * it should he closely woven and not open or sleazy. This material preferably includes a proportion of jute yams 415 5 and, generally speaking, best results are obtained with a combination of jute yarns and polypropylene which may be in the form of yarns or tapes. The use of polypropylene is not essential and this material may be replaced by, for example, a polyester material, an acrylic material, a polyamide material, a polyethylene material or a cellulosic material.

If polypropylene or one of the alternatives just mentioned is used without any jute at all, at least a proportion should preferably be fibrous e.g. either a staple yarn or fibri1lated, so as to provide a somewhat hairy texture which facilitates a direct bond with the foam layer.

In a preferred type of woven fabric used for the secondary backing the weft yarns are of jute which are preferably of a natural shade to assist in the simulation of a woven carpet. Jute by its nature is, of course, a hairy yarn. The warp is constituted by polypropylene tapes, two out of three of which are unfibriHated while the third is fibri11ated for the reason mentioned above.

If the fabric is to consist wholly of synthetic materials, the weft may also consist of staple yarn or similar tapes of polypropylene or one of the previously mentioned alternatives.

In order to produce a direct bond between the secondary backing and the layer of foam, a method of production in accordance with the invention includes the step of bringing the layer of foam and the secondary backing into contact with one another without the application of external pressure while the foam is still in a moist state so as to cause a degree of mutual penetration between these two layers sufficient to produce a direct bond between them but insufficient to lead to the presence of foam at the outer surface of the secondary backing, and then completing the lamination by the application of heat to cure and dry the foam. In order to achieve intimate contact between the layer of foam and the secondary backing, the foam needs to be evenly spread and the thickness of the layer carefully regulated. This may be achieved by means of a doctor roller or a doctor blade, preferably the former.

Preferably, the layer of foam is formed on top of the anchor coat on the side of the primary backing away from the pile and the secondary backing is then laid on top of the moist foam layer.

This completes the four-layer structure which is then subjected to heat to cure and dry the foam and thus complete the lamination. Generally speaking, it is preferable to dry the anchor coat before application of the foam layer, but it is also possible to apply the wet foam to the wet anchor coat and to dry both together.

An alternative method of bringing the layer of foam into contact with the secondary backing while the foam is still in a moist state is to apply the layer of foam to the secondary backing rather than to the dry anchor coat and then to laminate the two layers by the application of heat. The combination of foam plus secondary backing then has to be laminated to the primary backing, the anchor coat then performing the dual function of pile locking and forming the bond between the foam layer and the primary backing, thus again giving a four-layer structure.

When proceeding in accordance with the preferred method by forming the layer of foam on top of the dry anchor coat and laying the secondary backing on top of the moist foam layer, the secondary backing may be conveniently passed around a laminating device such as a roller mounted immediately above the surface of the foam layer so as to lay the secondary backing on top of the foam without the application of pressure as the foam passes beneath the laminating device. As previously described, the absence of external pressure is essential in order to avoid excessive penetration of the foam into the secondary backing with resultant 'strike through'. The partial penetration thus obtained leads to a highly effective direct bond between the foam and the secondary backing.

A method in accordance with the invention will now be. described in more detail, by way of example, with reference to the accompanying drawings, in which:Figure 1 is a diagrammatic view showing a complete production line; Figure 2 is a detailed view to an enlarged scale showing the formation of a layer of foam and the application of a secondary backing to the foam; and Figures 3 and 4 are diagrammatic sectional views showing the laminated structure of alternative forms of carpet: Turning first to Figure 1, unbacked carpet 1 drawn from a source of supply (not shown) consists of a tufted primary hacking and may be optionally pre-printed. Other types of non-woven floor covering having a pile surface may . also he treated by the same general process. After passing around a sequence of rollers 2, 3, 4 and 5, the unbacked carpet passes to an applicator 8 where a layer of anchor coat is applied, by means of a lick roller and a doctor blade. The anchor coat is, of course, applied . to the untufted side of the primary hacking which is downmost at this point, hut after passing around a further roller 10 the untufted side carrying the layer of anchor coat is uppermost. The anchor coated primary hacking, shown as 12, passes to a stenter 14 on which it . is supported while passing beneath infra-red heaters 15 mounted within an enclosure shown generally as 16.

The heaters 15 dry the anchor coat and bond the tufts firmly in position in the primary hacking. As illustrated, the stenter 14 terminates at a roller 17, hut if required . a single stenter may extend along the whole of the production line shown in Figure 1.

After leaving the stenter 14, the anchor coated carpet 12 passes in a generally U-shaped loop beneath an inspection platform 18 which gives the . operator close access to the next stage of the process which is the application of the foam.

The carpet 12, which has cooled since leaving the heaters 15, next passes to the foam application stage, shown in more detail in Figure 2 where it is supported by a table 19. A layer of foam is spread . on the top of the dried anchor coat and is supplied by a traversing distribution head 22 which traverses in reciprocal fashion across the width of the anchorcoated carpet. After leaving the distributor head 22, the layer of foam shown as 23 passes beneath a doctor . roller 25 which is adjustable in a vertical direction according to the thickness of foam layer required and this spreads the layer of foam evenly and regulates its thickness upon the anchor coated carpet as the latter passes beneath the roller.

. To the right of the doctor roller 25 is a laminating roller 30 around which secondary backing material 32 passes into contact with the upper surface of the foam layer 23, being drawn from a supply station 34 seen in Figure 1. The roller 30 . may be silicone coated and is adjustable vertical direction, being adjusted in accordance with the thickness of the foam layer 23 so as to lay the secondary backing material 32 on top of the wet layer of foam without the application of any pressure to . the carpet structure so that in effect the secondary backing rests on the foam. Immediately after this, the carpet is picked up by a main stenter 33 starting at a roller 35.

The carpet, now shown as 36, comprises its full complement of four layers, i.e. primary backing, anchor coat, foam layer and secondary backing and is carried by the main stenter 33 over a supporting table 37 which is situated slightly below the level of the pins on the main stenter 33 and then between a pair of smoothing rollers 38 arranged above and below the carpet respectively.

While the carpet travels over this distance the secondary backing material 32 which is resting on the foam layer 23 settles slightly into the foam while the foam penetrates the structure of the secondary backing material, thus providing the degree of mutual penetration necessary for a firm bond and avoidance of 'strike-through'.

The smoothing rollers are also adjustable in accordance with the thickness of the various layers and their function is both to correct any irregularities in the outwards facing surface of the carpet structure 36 and to maintain uninterrupted contact between the secondary backing 32 and the upper surface of the foam layer 23 without applying any appreciable pressure to the carpet structure.

The rollers are situated a few feet to the right of the laminating roller 30, between five and ten feet being a typical value for the spacing.

While still supporting by the stenter 33 and the table 37 the carpet passes beneath infra-red heaters 40 mounted within a heating chamber shown generally at 41. The effect of this heating depends on whether a gel or no-gel foam is used. In the case of a gel foam the foam structure is formed, whilst in the case of a no-gel foam only a surface skin is formed. In either case, a bond is established between the foam layer 23 and the secondary backing 32.

A bond is also established between the foam layer 23 and the anchor5 coated primary backing (either in the heating chamber 41 or in an oven 45 which follows) this being assisted by the uneven nature of the anchor-coated surface due to the base ends of the tufts which extend through the primary backing.

Finally, the carpet passes into the oven 45 where the foam is cured and dried and the bonds between the foam layer 23 and the secondary backing 32, and the foam layer 23 and the anchor-coated primary backing, are completed. Temperatures in the heater 41 and the oven 45 depend on a variety of factors such as the materials of the carpet, the speed of travel and the length of these two enclosures, but in general the temperature of the heater 41 is slightly higher than that of the oven 45, but the dwell time in the oven will be greater than under the heater 41.

The completed carpet is then removed from the stenter and taken away by a system of rollers to a storage station (not shown). While the use of infra-red heaters is illustrated as being the preferred arrangement, this is not essential and the initial setting of the foam can occur during the first part of its travel through the oven 45. 4L2.55 Figures 3 and 4 are diagrammatic illustrations of a cross section of two typical constructions of carpet produced in accordance with the invention, that shown in Figure 3 having a cut pile of low density, while that shown in Figure 4 has a looped pile of higher density.

In each of the two constructions, the pile is shown as 50, the primary backing as 51, the anchor coat as. 52, the foam layer as 53 and the secondary backing as 54. This constitutes the basic fourlayer construction in accordance with the present invention. In other words, there is a direct bond between the foam 53 and the secondary backing 54.

Examples will now be given of the different formulations for use in a method as carried out by use of the apparatus just described. z n r cj fc. A. (J O Ο Φ c +.> p m P o p ω P •r~ C > © P O P O x: ro cn EXAMPLE 1 - FILLED ANCHOR COAT FORMULATION IN DRY WEIGHTS E Φ Qi >> P in jz P cn k ·«»0 Φ cu rs w -C P cn s_ ·«t0 Φ CU 3 P c Φ •r* TO Φ k Cn c ΙΛ P , Ο P 5- k Φ P CU Φ C k jz O <0 POO er Φ co c tn Ο Ό (J ·<- ro fi ro Γ“- cn fi cn o ro ro ro Γ-. O o o O fi p. ro ro ro ro O O o I o o O o o ro 1 o o ro o o o o o cn σ fi φ JZ Φ P JZ Φ P © c i- x: ε Xf Φ Φ cn 3 φ φ -5 XJ T- ι— JZ ’r~ (0 XJ E k υ P f— 4-» f0 3 Xi 3 Ρ *σ I—* 10 k «X 23 XJ 3 Φ o u Φ Φ 23 +J r— X, >> Φ P •r- O c E 22 C -r- φ ε in >> o 3 φ ε C τ- 22 k 'Γ- Φ -j Φ Ό XJ U >>P k P P Φ p >» k i0 α- tn o · ω k P (0 χ: <0 W p <0 tn tn CL*-- 23 2> tn · Φ s >> Ο2Ό >» p -o* ro r~ ro o JZ · Φ ni CM o cu CUP P 23 T ft”0 ro cu l·-» <0 T- to >» © Φ = >> P E k k ·— p >1 X) Φ -—-ι- Φ U to ·<- XJ 22 -σ έ -J P to υ E Φ Φ X? ra c Φ >»,Λ ·»“ 4-J -CJ P t— x a sz k P r— ,Γ —1 <0 f— f0 o Φ cn o CU Φ c o >* 1— O r— w j= f— in —_x- +J <0 cl tn >> ω >> rO to P P XJ X X 6 CJ ·ι— k c E © ··“ o x O X 3 3 k Φ O «0 3 O 22 Φ Xi Φ Φ i— JZ P •I— φ p— k P k P -S ί= χ» P r— k k O cs r·— »0 «0 «0 (0 O (O c 10 •i— 10 3 O f0 O CJ i— CJ r— (/) E «0 3 Lu υ CO CO 3 CJ Φ £ XJ i. © P k •i— P r~ •I— f— tn E ··—. CL cn E O . cn O ro O σ cn ro fi r- >> >> P P >> •f— •P” P tn tn c c= w Φ Φ o u Q Q tn P >> »r— Φ i- 3 C2 ro ro ro E E cO cn ro ro P ε c fi Φ b- ε P fi cn c P O o o to in co tn E 1 XJ O o o r-* P ro O nJ tn U φ r— r— cn (0 a. JZ P CL ta O < cc H < ί.5ΰ EXAMPLE Π - ALTERNATIVE NOW-FILLED Ah-HOR COAT FORMULATIONS IN DRY HEIGHTS «3 ε φ oc IZ) D)P P ·«- GJ U 0 3 <0 s Q. u) σ> >> Ρ·ι- ί. S- Φ Q ¢2 cu Φ ο >» Ρ ΡΡ •Γ” Ρ ο Ε «3 Τ“ r— V) Γ— «Ζί (0 Ο Φ 44 2. Ε ρ— Ρ Ρ <0 Ρ ε S- Φ·Γ- ίθ C φ 4= Ρ ο ·ι- ε Ρ ΙΛ Ρ <Ο φ Ρ Ρ 44 Ρ Φ <0 Φ ·Γ“ ο Ο 4= Ε •γ- Ρ Ρ Φ Ρ χ: ο φ υ ο w Ρ •γ- (Ζ) ο. 3 Ρ 3 Ρ «— £_ Τ3 ·γ-> α (0 ο <13 . Ο·ί- Ό ·Γ“ S- U υ S- γ— Φ Γ— Ρ CU Φ >) Φ Ε φ .χ χ? χ- χ: ο .C Or- C υ ρ υ Ρ ρ < co σ» lo o rt· rt- rt- o in σί rt- oj Γ ΓΟΟ CO ο ο m ο ο σ ο oj ιη 04 ο ο «— ο ο σι Γ— Ρ φ Ε Φ •t— •σ «3 Ρ 3 -σ φ Ε Φ •r“ Χί (0 Ρ Ό 3 Φ Ο *3 Φ φ +J ε-tφ ε Ε ‘tr* Φ 43 (Ζ) ΡΧ3 •γ· X- ο φ «— 43 Φ 43 Ρ Ε •σ ι- Ρ •γ— Ο έ ο Φ •Ι- φ ε •Γ 3 ο Ε ε Φ τ- Ε ·Γ· Φ —1 Ρ 3 Χί XJ S- _] S- γ- Φ >» . >»5- Ο Ο ‘f- Ρ ί- Ρ Φ ω ΙΖί f— <ζι «3 V) (Ζ) ΙΖ) Φ «£ tn Ρ in ίο ο 04 Φ >> 04 Ο r- cu γ— 43 ιη ο. ο* = >> -C £?ιη >> 43 Μ υ <— Τ3 43 Χί Φ φ Φ Φ XI Ρ Ρ Χί Ρ Γ— Ρ Ο r— LU Φ «— Φ Ο Ε CL ο «— Ο r— ΙΖ) Φ Q. X >> (/) >) Ρ υ _ © X X υ •γ— ε ρ— σ χ σ χ λ Ρ 3 Φ 43 Φ _α φ Ρ ΙΖ) •ι- U Ρ Ρ S- Ρ $- 3 Χί ιζϊ φ to Φ Φ 3 Φ Ο ·ι- Ο Γ— Ο Γ— 40 00 > φ Ρ φ ε •Γ X Ο Ε CU ω ο υ (Λ ιο ιη OJ ο ε 04 ιη Ε ε \ Ρ cn ε C ιο Ο) ο φ Ρ Ε ιη ο Ο co 04 υ r— C ο 1 ιη ιζ> Χί 04 Ρ Ο φ ΙΛ υ φ ί- cn φ Ο. C Ρ CL Φ Ο < οι Ρ cr Φ ω TJ c Φ p X Φ TJ c <0 > i.

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XJ (ϋ P t/J Φ tP •d* EXAMPLE III - FOAM LAYER FORMATION IN DRY WEIGHTS tO P P JZ i- CT fO α. ω xi q tO P P i. x: η} oi a. ‘rΦ 3 0 0 ο Ο cn 0r~ ο ο o O ο ΙΛ ό 0 LO r— u Φ -0 c 3 ο» TJ P X r— JZ Φ 0 cn Ε P to 'r- Ο »0 £. X) Ρ Φ χ—«· 3 Φ TJ P< γ— Γ—· C φ <0 Ο Φ P x: >> Φ to CLXJ tj ε to CL ΰζ td -t- 0 H- ε LO P _J X= CL <0 CM 3 cl X «—’ X3 S- Ό C U1 Ρ O TJ Χ2 Φ Φ cn φ C to E >> Er- P •Γ- to φ r- to Cd ’Γ- Ρ £. O ΧΟ ε ΙΟ Ρ Ο >>CL. φ ·ι- Π3 Ε Q. p χ: Φ -j «Ο to >> ε Ρ υ X, Ε ra ε £» ο ♦Γ 3 C Ο £. Φ ra Ρ Ο TJ •γ- to φ Γ— ψ- to CO r— TJ Φ Γ- Ρ r— ί. 3 Γ- O Ο ·Γ> ro •Γ” 3 td = to υο Ρ 3 3 U, <77 0 Φ χ: φ p to Φ S- c Φ fO XJ r— C Φ 3 O ο 0 a 0 > •r* φ £. 5> 3 a I cn O CM O LD CO Φ cn c ro a: <± I Ε P Ε Φ cn E Φ Ρ tX> P to E >> «rf· O to •d* U QJ cn c rd OC a. ct The examples given above are all suitable for a wide range of non-woven floor coverings having pile surfaces of varying weights and materials. As mentioned originally, most advantages are obtained at comparatively low pile weights. The secondary backing, however, needs to be selected in accordance with the requirement mentioned previously and an example of this is as follows:EXAHPLE IV - SECONDARY BACKING FABRIC Closely woven construction comprising polypropylene warp and jute weft. The warp sequence comprises three polypropylene tapes, two of buff delustered, one white fibrillated and delustered. Weft spun jute preferably of a natural shade.

Claims (27)

1. A non-woven tKw 00.0011111 having a pile surface carrico by a primary backing, an anchor coat to bind the pile into the primary backing, a resilient layer of foam laminated to the anchor coat and a woven or non-woven secondary backing laminated directly to the foam so that its outer surface lies wholly outside that of the foam.

2. A non-woven floor covering according to claim 1 in which the secondary backing is at least partly fibrous.

3. A floor covering according to claim 1 or claim 2 in which the thickness of the foam is in the range of 1.0 to 4.0 millimetres.

4. A floor covering according to claim 3 in which the thickness of the foam is between 1.5 and 2.0 millimetres.

5. A floor covering according to any one of the preceding claims in which the foam comprises a rubber or rubber-like material.

6. A floor covering according to claim 5 in which the foam is latex-based.

7. A floor covering according to claim 6, in which the main constituent of the foam is a synthetic rubber.

8. A floor covering according to claim 6, in which the main constituent of the foam is styrene-butadiene rubber.

9. A floor covering according to any one of claims 5 to 8 ip which the foam is extended by a filler or fillers.

10. A floor covering according to any one of the preceding claims in which the anchor coat is in the form-of a collapsed foam.

11. A floor covering according to any one of the preceding claims in which the anchor coat is latex based.

12. A floor covering according to claim 10 or claim 11 in which the anchor coat is extended by a filler or fillers.

13. A floor covering according to any one of the preceding claims in which the secondary backing is a woven material including a proportion of jute yarns.

14. A floor covering according to claim 13 in which the woven material includes at least a proportion of polypropylene.

15. A floor covering according to claim 14 in which the polypropylene is in the form of tape.

16. A floor covering according to claim 15 in which at least a proportion of the tape is fibril!ated.

17. A floor covering according to any one of the preceding claims in the form of a tufted carpet.

18. A method of producing a floor covering having a pilesurface carried by a primary backing, an anchor coat to bind the pile into the backing, a resilient layer of foam laminated to the anchor coat and a woven or non-woven secondary backing laminated to the foam, which includes the step of bringing the layer of foam and the secondary backing into contact with one another without the application of external pressure while the foam is still in a moist state so as to cause a degree of mutual penetration between these two layers sufficient to produce a direct bond between them but insufficient to lead to the presence of foam at the outer surface of the secondary backing and then completing the lamination by the application of heat to cure and dry the foam.

19. A method according to claim 18 in which the foam is evenly spread and the thickness of the layer reguldted by means of a doctor roller or blade.

20. A method according to claim 18 or claim 19 in which the layer of foam is formed on top of the anchor coat on the side of the primary backing away from the pile and the secondary backing is laid on top of the moist foam layer.

21. A method according to claim 20, in which the anchor coat is dried before the application of the layer of foam.

22. A method according to claim 20 or claim 21 in which the secondary backing is passed around a laminating device mounted immediately above the surface of the foam layer so as to lay the secondary backing on top of the foam without the application of pressure as the foam passes beneath the laminating device.

23. A method according to claim 2 2 in which the laminating device is a roller.

24. A method according to any one of claims 20 to 23 in which the laminated assembly is passed through a smoothing arrangement after the secondary backing has been laid on top of the foam.

25. A method according to claim 24, in which the smoothing arrangement comprises a pair of rollers.

26. A method according to any one of claims 20 to 25 in which the assembly is held by a stenter during the application of the foam layer, the introduction of said secondary backing and the subsequent heating.

27. A floor covering when produced by a method according to any one of claims 18 to 26.