GB2151545A

GB2151545A - Process for producing a backing for tufted carpets and backing produced by this process

Info

Publication number: GB2151545A
Application number: GB08428546A
Authority: GB
Inventors: Norwin Schmidt
Original assignee: SCHMIDT J G JUN SOEHNE
Current assignee: SCHMIDT J G JUN SOEHNE
Priority date: 1983-11-11
Filing date: 1984-11-12
Publication date: 1985-07-24
Also published as: BE900430A; DE3340839A1; IT1178623B; DE3340839C2; GB8428546D0; IT8423480A0; GB2151545B; IT8423480A1; NL8402520A

Abstract

A process for producing a backing for tufted carpets proposes that a carrier layer (2) and a layer of non-woven fibrous material (4) be brought together and bonded under the effect of heat. The bonding is effected by means of an adhesive layer (6) consisting of a thermoplastic plastics material which has a lower melting point than the material of the two layers (2) and (4). The heat is adjusted accordingly so that only the adhesive layer (6) melts and partially surrounds and embeds the areas of the two layers which are to be bonded (2) and (4) which are closest to said adhesive layer. Any melting or fusion of the materials of the two layers themselves is thus avoided. <IMAGE>

Description

SPECIFICATION Process for producing a backing for tufted carpets and backing produced by this process The invention relates to a process for producing a backing for tufted carpets, wherein a woven fabric, underlay or similar carrier layer, particularly consisting of plastics strips or the like, is provided with a non-woven fibrous layer and bonded under the effect of heat.

The invention further relates to a backing produced by this process.

A manufacturing process of this kind and a corresponding backing are known, for example, from German Offenlegungsschrift 1 9 62 094, particularly page 11 of this specification. Non-woven fibrous structures, primarily fleeces, are applied to carrier layers comprising films, woven backing fabrics or other materials which are thermoplastic and bonding is produced by the application of heat in cohesive or locally limited areas. As a result, at least in the bonding area, the fleece no longer exists as such or can only be recognised as a fleece with difficulty. There is then a risk that the fleece will not be capable of being dyed at these places.However, the very purpose of such a fleece in a backing for tufted carpets is to receive the dye which is also contained in the pile threads, so that when the carpet is finished the backing fabric or underlay or the like does not show through.

Apart from this problem that the advantages of the fleece may be lost, particularly in the bonding regions, there is also a danger that the fusion will spoil the smoothness of the backing at least in parts.

German Offenlegungsschrift 27 24 733 describes a process in which a fleece is produced by mixing different fibres, some of which are fusible fibres which are intended to fuse with the carrier layer under the effect of heat. On the one hand this makes the fleece expensive and on the other hand the points of adhesion or bonding go right through the thickness of the fleece since the fusible fibres themselves are mixed in throughout the fleece. Furthermore, the backing fabric is subjected to some melting and again may lose some of its smoothness.

The aim is therefore to provide a process and a backing of the kind mentioned hereinbefore by means of which the non-woven fibrous material i.e. the fleece can be reliably bonded to the woven fabric, underlay or the like without impairing the upwardly facing part of the fleece at the bonding points or making it impossible to dye. Indeed, even at the bonding points, on the side furthest away from the bonding the fleece should remain substantially soft and fibrous and retain the qualities of a fleece. As a result, not only should it remain capable of being dyed after bonding to the backing fabric or the like, even in the bonding areas, but it should also be possible to achieve correspondingly large areas of bonding, possibly over the entire surface area, with correspondingly better adhesion of the two webs.

According to the invention there is provided a process for producing a backing for tufted carpets including a carrier layer of material such as woven fabric or underlay and a layer of non-woven fibrous material wherein the carrier layer and the non-woven layer are brought together and bonded at their interfaces under the effect of heat by means of a bonding medium which has a lower melting point than the non-woven layer and the backing layer. The bonding medium flows around the fibres of the fleece, nearest the carrier layer, and openings, undercuts or the like in the carrier layer.

Thus, after curing, the carrier layer and the fleece are embedded in this bonding medium at their interfaces and are surrounded by it so that they are positively locked together without being fused or melted themselves. Thus, the two constituent parts of the backing for the tufted carpet remain unadulterated and unaltered and, in particular, the fleece remains capable of being dyed even on and above the bonding points. At the-same time, a strong but smooth bond is also obtained.

It is particularly convenient to use plastics powder or liquid as the bonding medium. In this way, the bonding medium can be introduced particularly easily between the two layers which are to be bonded.

A preferably thermoplastic plastics powder may be used which melts, under the effect of heat, at a temperature below the melting points of the fleece fibres and the woven fabric or the like. It is also possible to use a liquid which hardens under the effect of heat at a temperature below the melting point of the fleece and the carrier layer.

It is particularly convenient to apply a plastics powder having a melting point above the boiling point of water, preferably from 105 to 1 50, Celsius. A carpet produced using this backing will then be boilable without the bond between the carrier layer and the fleece being undone. For example, a powder with a particle size of from about 10 to 300pm may be used.

In a particularly advantageous embodiment of the invention, the web of fleece is layed over the carrier layer and then the plastics powder is sprinkled or otherwise applied onto the fleece from above. Tests have shown that the plastics powder will penetrate through the spaces in the fleece as far as the interface with the carrier layer and, once there, can perform its bonding function in the desired manner. Moreover, individual particles of powder within the fleece can produce a strengthening without affecting the recepti veness to dye of the surface of the fleece. By way of example, from 3 to 30 grams of thermoplastic plastics powder may be applied for each square metre of backing.

The webs of carrier material and fleece which are to be superimposed may be pressed together, after the application of the plastics powder or the like, preferably by means of heated rollers. These cause the plastics powder to melt so that it can partly flow around the layers which are to be joined, at the interface thereof.

It is advantageous to use smooth rollers and replace the knubs conventionally associated with such rollers with the individual particles of powder. The rollers with which the two layers are fixed together are correspondingly cheap.

A major advantage of the process according to the invention, apart from the fact that the parts which are bonded together are unaltered, is that it can be carried out at lower temperature, i.e. with greater energy saving, than if the two substances which had to be bonded had to be melted. Moreover, by sprinkling on the powder. it is possible to fix the fleece at individual points, and again these fixed points will not affect the fibres of the fleece itself but will only join them together.

Since no precise mixing of different fibres is required, the overali production of the backing is cheaper. To satisfy different strength requirements, the manufacturer need only add more or less plastics powder, and this can easily be done by varying the outflow from a feed apparatus. By contrast, in the case of fleeces which are mixed with fusible fibres, different mixing ratios of the fibres have to be laboriously determined beforehand in order to meet different strength requirements in a similar manner. Furthermore, the process according to the invention does away with the need for the careful mixing required with mixed fleeces. In addition, the powder is cheaper than fusible fibres.

According to another aspect of the invention there is provided backing for tufted carpets with at least one carrier layer, such as a woven fabric or underlay, and with at least one non-woven fibrous layer, the one carrier layer and the one non-woven layer being connected by an adhesive layer therebetween.

The or each carrier layer may comprise a woven fabric or underlay, and preferably consists of plastics strips. The adhesive layer surrounds fibres, undercuts or the like in the two bonded layers.

The adhesive layer may consist of a plastics which has a lower melting point than the material of the two bonded layers which are partially embedded in the adhesive layer.

They themselves, however, remain unaltered so that the receptiveness to dying of the layer of fleece is unaffected. Moreover, the entire backing and, later, the carpet remain smoother and more flexible than if the layers of the backing were fused together.

It is sufficient for good adhesion if the adhesive layer is a thin film. The adhesive layer may also have interruptions or gaps.

However, it may also cover the entire surface area between the carrier and the fleece if correspondingly good adhesion is desired.

This backing has the advantages mentioned hereinbefore with reference to the process over a backing in which the two layers themselves are fused and thus virtually welded together. In fact, all fusion processes cause fibrous or woven or flat-laid structures to be partially transformed into a type of film which is then correspondingly less elastic or less openweave. The backing according to the invention in any case has on its upper side, a fleece structure which can readily be dyed so that any carpet produced from it will also have the desired dying properties. Compared with an arrangement wherein the two layers are coalesced, there is better adhesion, better wear-resistance and a longer life. Moreover, during the tufting process, the tufting needles are not contaminated with adhesive.

An embodiment of the invention is hereinafter described more fully with its essential details by way of example only and with reference to the accompanying drawings.

The drawings show, in partly diagrammatical form: Fig. 1 the production of a backing according to the invention the two layers of which are brought from different rollers and then coated with the bonding substance.

Fig. 2 shows a cross-section through the superimposed layers of a woven fabric, on the one hand, and a fleece, on the other, and Fig. 3 shows, on a greatly enlarged scale, the bonding of the two layers shown in Fig. 2 by means of an adhesive layer partly flowing round the surfaces facing each other.

A backing for tufted carpets shown in Fig. 3 and generally designated 1 is used to produce tufted carpets and comprises a carrier layer 2 in the form of a woven fabric of plastics strips 3 and a fleece layer 4 of fibres 5 adhering thereto. Between the carrier layer 2 and the fleece 4 there is an adhesive layer 6 which surrounds and encloses fibres 5 and undercuts in the plastics strips 3 of the two bonded layers 2 and 4. The adhesive layer 6 thus in practice forms a bond between the two layers 2 and 4 and provides a positively locking connection without in any way affecting the free surface of the fleece layer 4 by any fusion or the like. Thus, this fleece layer 4 is well suited, particularly, for dying with the dye imparted to the pile threads which are to be tufted through.

The adhesive layer 6 consists of a plastics material which has a lower melting point than the material of the two connected layers 2 and 4, which can thus be embedded unchanged in the adhesive layer 6. It is sufficient if the adhesive layer 6 is a thin film or consists of individual dots only, the adhesive flowing round sufficient areas of the two layers 2 and 4 but they themselves remaining flexible and pliable. If desired, the adhesive layer 6 may even comprise interruptions or gaps. However, to ensure good adhesion of the two layers 2 and 4, it may extend over the entire surface area thereof.

Fig. 1 in particular shows a process for producing the backing 1 as shown in Fig. 3.

The carrier layer 2 on the one hand and the fleece layer 4 on the other hand come from two different supply rollers 7 and 6. The two layers are guided together through guide rollers 9, as shown on a larger scale in Fig. 2.

Then a medium is introduced, consisting in the embodiment by way of example of a plastics powder 10 which has a lower melting point than the fleece 4 and carrier layer 2.

This powder passes through the spaces between the fibres 5 of the fleece layer 4 and thus reaches the interface between the two layers 2 and 4. Under the effect of heat it can then be fused so that it flows around the lower fibres 5 of the fleece 4 and any openings, undercuts and the like in the carrier layer 2. After the adhesive layer 6 thus formed has hardened, the carrier layer 2 and fleece 4 are thus partly surrounded by this medium at their interface layers and are positively connected in the manner described, without themselves having been fused or melted.

The thermoplastic plastics powder used may have a melting point above the boiling point of water so that any carpet produced therewith is resistant to boiling. About 3 to 30 grams of this plastics powder 10 may be sprinkled on per square metre of backing.

Fig. 1 also shows that, after the plastics powder 10 has been applied, the two layers 2 and 4 together with this plastics powder 10 are heated and compressed by means of heated rollers 11, whereupon the particles of plastics powder are melted. Smooth, unetched rollers 11 are sufficient for this purpose, since the individual powder particles replace the knubs which would otherwise be required in the manufacture of fleeces or the like. Downstream of the rollers 11 is a hardening area 12, after which the finished backing 1 can be wound onto a storage roller 1 3.

All the features and constructional details given in the specification, abstract, claims and drawings may be essential to the invention both individually and in any desired combination with one another.

Claims

1. Process for producing a backing for tufted carpets, including a carrier layer of material such as woven fabric or underlay and a layer of a nonwoven fibrous material wherein the carrier layer and the non-woven layer are brought together and bonded at their interfaces under the effect of heat by means of a bonding medium which has a lower melting point than the non-woven layer and the backing layer.

2. Process as claimed in claim 1, wherein plastics powder or liquid is used as the bonding medium.

3. Process as claimed in claim 1 wherein the bonding medium is a thermoplastic plastics powder which is fused under the effect of heat at a temperature below the melting points of the non-woven layer and the carrier layer.

4. Process as claimed in claim 2 or 3, wherein the powder has a particle size of from about 10 to 300 ym.

5. Process as claimed in any of claims 2 to 4, wherein the non-woven layer is placed on the carrier layer and then the plastics powder is sprinkled or otherwise applied to the nonwoven layer from above.

6. Process as claimed in any of claims 2 to 5, wherein about 3 to 30 grams of the plastics powder are applied per square metre of backing.

7. Process as claimed in any of claims 2 to 6, wherein the superimposed webs of the carrier layer and the non-woven layer are compressed, preferably by means of heated rollers after the application of the plastics powder.

8. Process as claimed in any of claims 3 to 8, wherein smooth, unengraved rollers are used to melt the plastics particles and compress the layers.

9. Process as claimed in any of claims 3 to 9, wherein the non-woven layer is fixed at individual points by means of individual powder particles in its interior.

10. Process as claimed in claim 1 or 2.

wherein the bonding medium used is a liquid which, under the effect of heat, hardens at a temperature below the melting points of the non-woven layer and the carrier layer.

11. Process as claimed in any preceding claim wherein the bonding medium, has a melting point above the boiling point of water.

1 2. Process as claimed in claim 7 wherein said melting point is from 105 to 150 Celcius.

1 3. Backing for tufted carpets with at least one carrier layer, such as a woven fabric or underlay, and with at least one non-woven fibrous layer, the one carrier layer and the one non-woven layer being connected by an adhesive layer therebetween.

1 4. Backing as claimed in claim 13, wherein the adhesive layer consists of a plastics substance which has a lower melting point than the material of the two bonded layers which are partially embedded in the adhesive layer.

15. Backing as claimed in claim 13 or 14, wherein the adhesive layer is a thin film.

1 6. Backing as claimed in any of claims 14 to 17, wherein the adhesive layer comprises interruptions or gaps or extends over the entire surface area of the backing.

1 7. Backing as claimed in any of claims 1 3 to 1 6 or process as claimed in any of claims 1 to 1 2 wherein the or each carrier layer consists of plastics strips.

1 8. A process for producing a base material for tufted carpets, substantially as herein described with reference to any of the accompanying drawings.

1 9. A backing for tufted carpets substantially as herein described with reference to any of the accompanying drawings.

20 A backing for tufted carpets produced by a process as claimed in any of claims 1 to 12, 17 and 18.