GB2159730A - Method of producing a flocked, flat-shaped textile structure, and a flexible, flat-shaped flock structure produced thereby - Google Patents

Abstract

The invention relates to a method of producing a flexible, flat-shaped flock structure formed from a substrate, adhesive layer and flock, said method comprising calendering the flat-shaped structure after the flocking process. This method permits a fine surface to be achieved with a uniform nap. The calendered, flat-shaped flock structure may be additionally embossed. This enables any desirable surface texture to be obtained. Depending on the choice of substrate, adhesive and flock, improved properties in respect of appearance, resistance to wear by friction, bi-elasticity, air-permeability, insulating effect and feel, can be obtained.

Description

SPECIFICATION Method of producing a flocked, flat-shaped textile structure, and a flexible, flat-shaped flock structure produced thereby The present invention relates to a method of producing a flocked, flat-shaped textile structure, and also relates to a flexible, flat-shaped flock structure which is formed from a substrate, an adhesive layer and a flock layer which has improved properties.

According to the manual entitled "Die texi len Rohstoffe", 6th edition, 1981, E. Wagner, Page 159, flocked, flat-shaped textile structures are described in the form of imitation chamois leather, imitation velvet, imitation plush material and imitation skin or hide, and also in the form of velour paper and synthetic leather.

A flat-shaped structure of such type is subjected, for example, to a compression (crash) process. Abrasives serve to assist therein. It is also known to emboss flat-shaped structures.

In order to obtain patterns and coloured effects, it is known, in accordance with German Patent Specification No. 832 11 2, to treat a flocked, flat-shaped structure by means of airblasting. This causes a change in the inclination of the flock fibres whereby they migrate in different directions.

The known flat-shaped, flock structures are extremely coarse and not very pliable, and their surface is matt and coarse and is more like a felt material. Its utilisation is limited in respect of its resistance to wear by friction, its elasticity and its good handling quality or feel.

Known purifying treatments are expensive and increase the costs of the product.

The invention seeks to provide a flocked, flat-shaped substrate structure which is economically purified and is substantially improved, by comparison with known flatshaped flock products or articles, in respect of its quality and wearability.

These features include, for example, the bielasticity, the feel, the resistance to wear by friction, air-permeability, the insulation effect and the appearance. Depending on the subsequent intended use, the fineness of the surface of the flock layer should selectively correspond to that of drape6, worsted wool or flannel. These are qualities which are only possible in the textile industry when expensive and/or complex textile equipment is used.

The technical object of the invention is to improve the method of the above-mentioned type in such a manner that the flat-shaped flock structure is subjected to a uniform, mechanical treatment to permit a purified flatsahped flock structure with improved properties to be obtained economically.

According to the present invention, there is provided a method of producing a flat-shaped textile structure comprising a substrate, an adhesive layer and a short-fibre layer (flock), wherein an aqueous adhesive layer is applied to the substrate surface, and a flock layer-formed from substantially vertical, electrostatically prepared short fibres-is flocked into the adhesive surface in respect of its entire density, and the flocked, flat-shaped structure which is obtained is dried, structurally fixed, surface-treated-possibly purified-then cleared of flock fibre remains and rolled up, in which, after the flocking process, the flat-shaped flock structure which has not be condensed-out, is calendered once it has been previously cleared of surplus flock fibres.

The surplus flock fibres are preferably removed by suction.

The flat-shaped flock structure has a surface which has been flocked in a uniformly dense manner and is continuously pressed during the calendering process. This pressing process by means of rollers causes the layer thickness to change and exerts upon the flock fibres a uniform wrapping-over of the free ends and additional securement of the flocked ends.

A fine, uniform direction of the nap is achieved in this manner on the flock surface.

The flock fibres remain unchanged in this position during further drying and fixing treatment and provide the surface with an extremely fine to fine appearance of a quality comparable with drape8, worsted wool or flannel.

If the calendering process is effected when the adhesive layer is wet, the fine surface is given a very silky lustre, but the silky lustre is somewhat reduced if the adhesive layer is semi-wet. If the calendering process is effected when the adhesive layer is air-dried to surface-dried, the flock layer has a dull of matt finish later. The extent of surface fineness and sheen may additionally be influenced by selective cold- or hot-calendering.

Due to the procedural treatment and construction of the flat-shaped textile structure, which has a substrate as the carrier material and an adhesive layer with flock, the fabric and/or foam layer or film on the underside and the layer of foam adhesive together with the flock layer on the upper side ensure that the improved properties of the new, flexible flat-shaped structure are achieved. The flatshaped structure not only has a fine appearance, but it is also soft to the touch and pliable. This has not been achieved until now for flat-shaped flock structures. The flatshaped structure is extremely resistant to wear by friction. The uniform flock nap does not change with surface friction. The flat-shaped structure is light in weight, as well as being soft, bi-elastic and air-permeable. It has good insulating properties and is easy to use as a covering material.

By comparison, woven articles with such properties would require expensive and/or complex textile equipment to effect, for example, multiple wet nap-roughening and cutting. However, not all of the properties which are inherent in the above-described flatshaped flock structure can be achieved with woven articles.

According to an alternative embodiment of the invention, the calendered, flat-shaped flock structure may be additionally embossed or partially embossed. Depending upon the desired pattern, for example, the following pictures or designs may be achieved: a Donegal tweed pattern, a coarse to fine cloth or linen basket weave, a herring-bone or square pattern, a strip-type or nap weave or any kind of imaginary wave pattern.

The embossing effects must not be clearly visible. They may only be evident with different refractions of light. The embossing effects may also be clearly visible in a predominantly rustic manner. It is possible that the texture may extend beyond the height of the flock.

The lustre of the surface is interrupted at various locations by the embossing effects, so that the surface additionally appears threedimensional.

The procedural treatment by way of calendering, drying and embossing may be modified in such a manner that, instead of effecting embossing immediately after the calendering process, the calendered, flat-shaped flock structure is initially dried and only embossed thereafter. This makes the embossed contours or outlines more clearly visible and provides the surface with a decorative appearance.

The possible variations are not only provided by the above-described procedural steps according to the invention, but they are also provided by the use of predetermined, but selectable materials for the substrate, adhesive and flock.

The substrate may solely be comprised of a type of fabric, a woven or knitted article, a double-ribbed article or a similar carrier. However, it may also be in a two-layered form, coated, for example, by a layer of soft foam or by a soft film. These layers may be joined together as a lining, preferably a flame-resistant lining. To achieve a light weight, stability of structure and air-permeability, the adhesive may preferably be comprised of an aqueous dispersion-type foam (substance) adhesive, more especially a polyurethane foam adhesive or acrylate adhesive. Such adhesives are highly suitable for use in flat-shaped, flock structures. They are environmentally acceptable, have large cells, are lightweight and stable in structure and adhere very well to substrate and flock.

According to the type of material, denier and cut length, the flock fibres influence various properties of the surface structure. In the case of viscose flock, which has a fine denier and is of average length, the web product or sheeting is provided with a softer finish compared with polyester flock.

In the case of polyamide, for example, the fibre fineness is between 1.7 dtex and 3.3 dtex. The cut length of the fibres is preferably between 0.5 mm and 1.5 mm. Basically, all known flock structures may be used to flock a layer of short fibres, such layer preferably being flocked in its entire density.

The method according to the invention and the flexible flat-shaped flock structures obtained thereby are explained more fully with reference to exemplified embodiments and as shown in the accompanying drawings, in which: Figure 1 is a schematic view of an apparatus for producing a flocked, flexible, flatshaped textile structure, said apparatus being provided with a calendering device; Figure 2 is a schematic view of an alternative apparatus for producing a flocked, flexible, flat-shaped textile structure, said apparatus being provided with a claendering device and an embossing device; Figure 3 is a schematic view of part of a modified apparatus as shown in Fig. 2; and Figure 4 is a schematic view of part of a further modified apparatus as shown in Fig. 2.

Example 1 The substrate comprises a 100 g/m2 lightweight polyamide-filament product which has a flame-resistant lining provided by a 2 mm thick layer of soft ester foam. An air-foamed acrylate adhesive with a foam weight of 300 g/l is roughened to a foam thickness of 300 ym. A polyamide flock, having a denier of 1.7 dtex and a cut length of 0.7 mm, is electrostatically flocked into the substrate.

After the flocking process, the flat-shaped flock structure is cleared of surplus flock fibres and calendered when the adhesive layer is in its wet state. The flat-shaped flock structure is dried in a drying conduit, then fixed by an additional heat-treatment process, and thereafter cleared of surplus flock and rolled up.

The surface is comparable with an extremely fine worsted wool, has a silky lustre and is soft. The web is bi-elastic, air-permeable, lightweight and soft.

Example 2 A flat-shaped flock structure is prepared as in Example 1. After the calendering process, the flat-shaped structure is embossed when wet. The embossing effects are visisble and are comparable with a fabric texture. The silky lustre is interrupted at various locations by the different embossing planes. The appearance is full and three-dimensional.

Example 3 A flat-shaped flock structure is prepared as in Example 2. Instead of using the thin soft ester foam, a 1 5.5 mm thick soft ester foam is joined to the fabric as a flame-resistant lining. The surface is fine and has a silky lustre. The flat-shaped structure is soft, airpermeable and bi-elastic and has both soundand heat-insulating properties.

Example 4 The substrate comprises a 2 mm thick soft PVC film, and an adhesive is scraped thereon.

The flock is a polyamide having a denier of 1.7 dtex and a cut length of 0.7 mm. It is electrostatically flocked.

The flat-shaped flock structure is cleared of surplus flock, dried slightly, then calendered and embossed. Thereafter, the flat-shaped flock structure is fully dried, fixed and cleared, and it appears as a flexible web product having a fine, decorative flannel-like nature with a nap weave of such texture.

Fig. 1 of the drawing is a schematic view of an apparatus for producing a flat-shaped flock structure, having supporting or conveying rollers 1 for a substrate 2. A scraper 3 applies an adhesive or aerated adhesive 4 to the surface of the substrate 2. The flocking apparatus 5 flocks the electrostatically prepared flock fibres into the adhesive layer. The flock layer 6 is cleared of surplus flock by means of a suction device 7.

A calendar is referenced 9. The flat-shaped flock structure 8 is guided through the roller gap of the calender, thereby being subjected to a uniform surface-treatment and pressing process. Depending on whether the calendering process is effected when the adhesive layer is wet, semi-wet or surface-dried, the surface pattern accordingly has a silky lustre or a dull finish, with a very fine or fine uniform direction of nap. The surface is smooth. The calendered, flat-shaped flock structure 10 is subsequently conducted through a drying zone 11 and a combined drying and fixing zone 13, and then it is cleared by a clearing device 1 5 and rolled up into a roll 16.

Fig. 2 of the drawing is a schematic view of an alternative apparatus for producing a flatshaped flock structure. It is basically identical to the apparatus shown in Fig. 1, but it additionally comprises an embossing roller 1 7. The embossing process may also be effected by an embossing template. The embossing process provides the calendered, flatshaped flock structure with a surface texture which is predetermined by the subsequent intended use, but such texture is selectable. If the embossing process is effected when the adhesive layer is still wet, semi-wet or slightly surface-dried, the texture may be very fine to fine but, in its finished state, it is only visible by refraction of light.One possible modification is shown in Fig. 3 wherein a drying zone 1 9 is provided before the calendering process, and another possible modification is shown in Fig. 4 wherein a drying zone 21 is provided between the calendering and embossing processes. In the latter case, the calendering and embossing processes are effected when the flat-shaped flock structure has been surfacedried or pre-dried. These surface textures are visible in that they protrude for an average to a considerable extent. Such textures may even resemble a rustic pattern and yet still be pleasant to touch.

Both the calendered and the calendered and embossed flexible flat-shaped, flock structure according to the invention have fine surfaces, such as were not achieved in the past, and, when embossing is effected, the texture is also finer than was achieved hitherto. Even in the event of surface friction or rubbing, these surfaces do not alter in respect of their fineness, nap direction and texture. In addition, they are also very resistant to wear by friction.

Moreover, the surface is very soft to touch and is kind to the skin.

The various substrates--a) a) a woven and knitted article or a double-ribbed article with or without an additional layer in the form of a soft foam or soft film layer, lined prior or subsequent ot the flocking process; b) a film layer in soft or semi-hard form; or c) a foam layer in soft or semi-hard form-permit a variety of flat-shaped, flock structures to be produced which differ in different properties and are preferably used for car interiors, for upholstery purposes and for decorative and wall-covering materials. In turn, the various adhesive layers used, irrespective of whether they are dispersions, foam adhesives or adhesive films or pastes, influence different properties of the flat-shaped flock structures. Finally, the various types of flock structures, which vary in respect of material, denier and cut length, are also responsible for the different properties regarding appearance, pattern, touch and texture.

Furthermore, the calendering and/or embossing process may be adapted so that properties, which are predetermined according to the subsequent intended use of the flatshaped flock structure, can be obtained in a quality not hitherto achieved.

Claims (14)

1. A method of producing a flat-shaped textile structure comprising a substrate, an adhesive layer and a short-fibre layer (flock), wherein an aqueous adhesive layer is applied to the substrate surface, and a flock layer-formed from substantially vertical, electrostatically prepared short fibres-is flocked into the adhesive surface in respect of its entire density, and the flocked, flat-shaped structure which is obtained is dried, structurally fixed, surface-treated-possibly purifi end 'hen cleared of flock fibre remains and rolled up, in which, after the flocking process, the flat-shaped flock structure which has not been condensed-out, is calendered once it has been previously cleared of surplus flock fibres.

2. A method as claimed in claim 1, wherein the flat-shaped flock structure, comprising a wet adhesive layer, is calendered whilst in its wet state.

3. A method as claimed in claim 1, wherein the flat-shaped flock structure, comprising an adhesive layer which has dried slightly because of the surrounding ambient air, is calendered whilst in its dried or surfacedried Mate.

4. A method as claimed in claim 1, wherein the flat-shaped flock structure is subjected, after the flocking process, to a first drying process by means of heat-treatment and is calendered in this dried or surface-dried state.

5. A method as claimed in any one of claims 1 to 4, wherein the flat-shaped flock structure is cold-calendered.

6. A method as claimed in any one of claims 1 to 4, wherein the flat-shaped flock structure is hot-calendered.

7. A method as claimed in any one of claims 1 to 6, wherein the flock surface of the calendered flat-shaped flock structure is embossed.

8. A method as claimed in any one of claims 1 to 6, modified in that the calendered, flat-shaped flock structure is initially dried and then embossed.

9. A method of producing a flat-shaped textile structure, as claimed in any preceding claim, substantially as hereinbefore described, exemplified and illustrated in the accompanying drawings.

1 0. A flexible, flat-shaped flock structure, comprising a substrate, an adhesive layer and a short-fibre layer (flock) and produced in accordance with any one of claims 1 to 6, in which the flat-shaped structure includes a substrate formed from fabric and a layer of soft foam or film, an aqueous elastomeric adhesive, and a flock layer having a fine surface which is comparable with drape6, worsted wool or flannel.

11. A flexible, flat-shaped flock structure as claimed in claim 10, in which the aqueous elastomeric adhesive is a foam adhesive.

1 2. A flexible, flat-shaped flock structure as claimed in claim 11, wherein the fabric is a kntted, woven or double-ribbed article, the layer of soft foam is joined to the fabric as a flame-resistant lining, the foam adhesive is an aqueous dispersion-type foam adhesive, and the flock is formed from short fibres having a fineness of from 0.9 dtex to 3.3 dtex and a cut length of from 0.5 mm to 1.5 mm.

1 3. A flexible, flat-shaped flock structure as claimed in claim 12, in which the foam adbesive is a polyurethane dispersion.

14. A flexible, flat-shaped flock structure produced in accordance with any one of claims 1 to 6, wherein the flat-shaped structure includes a substrate formed from a layer of soft foam or film, an aqueous elastomeric adhesive and a flock layer having a fine surface which is comparable with drape6, worsted wool or flannel.

1 5. A flexible, flat-shaped flock structure as claimed in any one of claims 10 to 14 and produced in accordance with any one of claims 1 to 8, wherein the surface of the flatshaped flock structure has a loose texture which is comparable with an interlacing appearance.

1 6. A flexible, flat-shaped flock structure as claimed in claims 10 to 14 and produced in accordance with claims 1 to 8, wherein the surface of the flat-shaped flock structure has a strong texture which is comparable with a rustic appearance.

1 7. A flexible, flat-shaped flock structure as claimed in any one of claims 10 to 16, substantially as hereinbefore described, exemplified and illustrated in the accompanying drawings.