DE19804418A1 - Padded underlay for textile wall coverings etc. - Google Patents

Abstract

The padded underlay (3) for use with decorative and/or cladding materials (1) with an adhesive (2), is of textile fibers in a combination of 10-95 wt% of polyester fibers with a spiral crimp and 5-50 wt% of a core/mantle bicomponent fiber, and 0-85 wt% of a filling fiber mixture. The core/mantle bicomponent fiber has a core and mantle of crystalline polyester. The mantle has a melting point of \-140 deg C. The fibers with a spiral crimp are of shrunk polyester fibers, and they can also be a bicomponent fiber in a side-by-side structure. The filling fibers are of polyester with a fixed spiral crimp and/or fibers with a two-dimensional crimp. The fibers with a two-dimensional crimp are of natural or synthetic materials, or natural polymers and preferably viscose fibers. Or the fibers with a two-dimensional crimp are wholly synthetic.

Description

The present invention relates to voluminous fabrics for the sub upholstery of decorative layers. Such layers for padding can be found e.g. B. in the living area, for example under textile wallpaper, to emphasize a voluminous structure of the decorative fabric and the To improve heat insulation, for upholstered furniture, to underlay the Upholstery fabric, for example around the side armrest areas to be more voluminous and in the automotive and truck sector, for padding of the seat fabric and the lining materials in the interior for example of inner door panels, dashboards, in Headliner area and in the floor area.

The decorative materials used are depending on the requirements mostly substrates from the group of textiles, such as. B. tissue (also Car seat cover fabrics), knitted fabrics, knitted fabrics, scrims or nonwovens, or from  the group of foils or synthetic leather, or from the group of leather. Such decorative materials serve the surface of objects such as walls, upholstered furniture or vehicle interiors shape. However, since this is usually a more or less flat or two-dimensional structures, there is often a need to To make the decorative layer a little more voluminous, especially since it is hard Substrate with the decorative layers mentioned can be unsightly or can cause an uncomfortable feeling when touched.

It is known to use so-called welding pads for such a purpose which usually consist of a foam, which with, the High frequency machinability favoring fibers, and possibly one Cotton nettle is needled. The decorative layer is by means of High-frequency technology welded to the welding pad. This technique but requires polymers with a dipole character, which is why the decorative layer at least partially PVC or other halogen or pseudohalogen containing Must contain polymers. Due to the environmental discussion about halogenated This technology is hardly used anymore for polymers.

A frequently used upholstery is a thin, e.g. B. 2-8 mm thick foam. The advantages of foam padding are undoubtedly the low price, the pleasant softness, which is precisely adjustable, as well as the excellent resilience even after repeated loading.

This foam was preferably flame-laminated with the Decorative fabric connected. For this purpose, a 0.2 to 1 mm thick foam was used Adhesive used by being liquefied by gas flame and the Decor and the foam under-cushion layer glued. This method is due to the resulting flame treatment of the foam Toxic gases have come under criticism and are often used today more environmentally friendly lamination processes have been replaced.  

Another serious disadvantage of the foam is that in its raw state insufficient flame resistance according to, for example, in the automotive sector required flame retardant standard MVSS 302. The flame retardant Availability can only be achieved by adding flame-retardant chemicals kalien be achieved. However, this does not reinforce the foam anyway Insignificant so-called fogging effect, i.e. the precipitation from out Plastic volatile substances on the windows, not only at Neufahr testify. Fogging is not only uncomfortable because it is milky Veil forms on the vehicle window, but also affects the Traffic safety, because the lights are more responsive at night Vehicles glare and reflections occur.

Another problem that can arise with foams is that poor aging behavior. With increasing vehicle life can foam due to the frequent cold / heat alternating loads in connection with strongly changing air humidity age and before The course of vehicle life must be destroyed.

For this reason, alternatives to Foam padding wanted.

The use of pure needle-punched nonwovens, which are made from single-variety Synthetic fibers or made of garnetted stock, and if necessary may be needled onto carrier materials such as gauze or spunbond. Such nonwovens have the disadvantage that to achieve the required Resilience requires the use of an increased basis weight will, since the required property of good resilience, too after repeated exposure, only through the use of high materials Density, i.e. due to a high basis weight in relation to the material thickness can be achieved. However, increasing the density causes the negative Effect that the required softness in comparison to the foam is not can be achieved.  

EP 763418 (Daimler Benz) describes a method for producing a multilayered web made of outer fabric and an underlying nonwoven fabric described. The nonwoven fabric mentioned in this document must be a nonwoven fabric with a high standing fiber content, which additionally with binding fibers is stabilized. As a manufacturing process for the nonwoven fabric Dilution process or sewing process or the so-called Struto process mentioned. The pre-consolidated non-woven material containing binding fiber is thermally treated in a thermofusion zone and over Guide bands calibrated with a tapering distance. Subsequently can be lined with the decorative material in the same line occur.

The property right does not specify the type of binding fibers, nor discussed in more detail the type of carrier fibers. One only mentions for example the use of a "bicomponent binding fibers, in which two thermoplastics of different melting points, e.g. B. 140 ° C and 220 ° C, in a concentric arrangement with the lower melting Plastic on the outside ". In the case of the carrier fibers, the Possible use of tear fibers or the use of polyester fibers from certain fiber dimensions, it must be assumed that it is a fiber with a conventional and mainly common one two-dimensional ripple structure.

Needle or active nonwovens from such fiber mixtures show usually various disadvantages, which the use in particular Padding for parts with difficult contours or shapes in question put. Such nonwovens tend to bend around sharp edges or in three-dimensional shaping for the formation of creases, which are through the decorative fabric and the appearance of the surface in in an unacceptable way.  

This can be explained by an excessive course of the amorphous Enamel jacket of the biko fiber, which causes the relative fiber movement in the Nonwoven is severely restricted.

Such behavior is also referred to as "rolling behavior". The Appropriate testing is done so that you have the two ends of the However, the pattern is put together in a U-shape without being folded. Then they will Ends parallel, but shifted in the opposite direction so that there is movement at the bending point. It is judged whether the movement smooth, round (= clean rolling) or whether there are any creases.

The use of these conventional fibers still requires use an increased basis weight, since the required property of the good Resilience even after repeated loading, with such Fibers, only through the use of high density materials, i.e. through an im High grammage can be achieved in relation to the material thickness. This is a second disadvantage of such materials compared to foams given, namely the relatively hard loss of goods, which is necessarily accepted, but is in need of improvement. The high Basis weights of such materials in connection with the mentioned relatively slow manufacturing dilourization, Sewing processes or the so-called struto process also result in high prices such article.

The above-mentioned higher basis weight also has an effect on the efforts of motor vehicle Engineers countered by reducing fuel consumption lower the vehicle.

The under-upholstery fabric according to the invention does not show these disadvantages. Here the properties are surface smoothness, good softness, good Resilience, even after repeated loading, good rolling behavior (consequently no crease formation), good elasticity, low Dense, low weight, low price, ideally combined in one.  

In addition, the upholstery fabric according to the invention offers the advantages of extremely low tendency to fogging, as well as fulfilling the Flammability standard MVSS 302 without any addition of Flame retardants.

The upholstery fabric according to the invention is after the needle punch process produced, as described, for example, in the author's book "Nonwovens" "Lünenschloß" Georg Thieme Verlag Stuttgart, on pages 67 to 103 and 122 to 142 are described, and a temperature treatment subjected as described on pages 215 ff. of the same book is.

The upholstery fabric according to the invention consists primarily of Polyester fibers, which have the property of being exposed to heat shrink while forming a spiral ripple. Are suitable for this for example, bicomponent fibers of the side-by-side type, which the Have a lower crimp intensity when delivered and / or to have a different crimping characteristic than after one for example heat treatment integrated in the process. Such fibers are for example under the name "Tergal X 403" at the company Rhone Poulenc available and consist of a side-by-side biko structure made of polyethylene glycol terephthalate in one half and polybutylene glycol terephthalate in the other half. When exposed to heat, they shrink two halves of the fibers are different, similar to a bimetal, and form such a denser ruffled three-dimensional structure. The number of With such fibers, crimped sheets can differ, for example, from originally 10-13 sheets / inch to 50-70 sheets / inch after the Change heat treatment. The result, of course, is shrinkage and one associated densification of the nonwoven. Such Shrinkage of the nonwoven material causes homogenization of the Surface image because of the fleece manufacturing and needle processes conditional thin spots due to the shrinking of the nonwoven caused contraction can be reduced.  

Such fibers can also be conventional in their original state Have 2-dimensional crimp, with the spiral crimp first after the heat treatment described.

Also fibers that have a spiral crimp after thermal treatment without the said biko structure are suitable.

By using the fiber mentioned, the rolling behavior of the Nonwoven improved significantly. This could be explained in such a way that, conditionally due to the shrinkage and the three-dimensional crimp, the fibers themselves align in the fleece and not, as with the two-dimensional mentioned crimped fibers, usually in a preferred direction Carding direction results. This shows the invention Padding material has a more isotropic rolling behavior, which causes no more wrinkles form.

Spiral-crimped fibers in the nonwoven additionally cause this one receives foam-like character. While a nonwoven made of 2- Dimensionally crimped fibers, even if it, as in EP 763418 described, at least 20% perpendicular to the surface aligned fibers, and contains binding fiber, and is soft when only squeeze a noticeable after about two thirds of the way Resistance, that is to say a cushion effect, is set by the invention Nonwoven fabric made of spiral-crimped fibers after a maximum of 20% of the Considerable resistance to deformation, however without appearing hard. This characteristic is very similar to that of the foam. Furthermore, the spiral-crimped fiber provides better resilience, even after repeated stress, as known padding materials with conventional 2-D crimped fibers. This could be explained Effect in that the spiral-crimped fibers as three-dimensional spherical aggregates are present in the nonwoven fabric and not, as with 2- Dimensionally crimped fibers in a flat or vector shape Alignment.

These advantages mean that the material density and therefore also that Basis weight by at least 15%, but usually at least 20-50  % compared to the padding materials made from conventional fibers can be reduced.

For cost reasons, the above-mentioned spiral curled Bicomponent shrink fiber partly through already fixed spiral-crimped fibers or by conventional, 2-dimensional crimped fibers preferably made of polyester, but also made of fibers other polymers, or be replaced by natural fibers. A minimum share of approx. 10% by weight of spiral-crimped bicomponent shrink fiber in the Nonwoven is necessary.

Such fixed spiral crimped fibers are, for example, under the Description Dacron T 88 from Du Pont de Nemours, Wilmington, available. An example of a 2-dimensional crimped fiber is Trevira Type 290 from Trevira GmbH mentioned.

An essential part of the upholstery according to the invention materials is the binding fiber in a weight percentage of the nonwoven of 5% - 50%, preferably 5% -30%. A consolidation by the widespread amorphous bicomponent fibers consisting of a crystalline PET core and an amorphous jacket made of a copolymer of terephthalic acid and isophthalic acid and glycol (of the type Melty 4080, Melty 3380, Melty 2080 all Unitika Ltd. Osaka) would have the disadvantage that precisely with such amorphous types, the melting points cannot be clearly defined and the softening of the fibers begins at 70 ° C (Glass transition temperature, or here: realxation temperature). A continuous temperature rise above this glass temperature of 70 ° C has a continuous weakening of the thermal stability of the nonwoven Consequence and this would be unsuitable for use in the automotive sector do. Furthermore, at the usual shrink temperatures spiral-crimped bicomponent shrink fiber from 160 to 190 ° C liquefy the amorphous melt jacket so that the melt closed around the spiral-crimped bicomponent shrink fiber and neutralize their positive properties for the most part would.  

According to the invention the problem is solved in that for solidification a sheath / core fiber made of crystalline polyester (sheath) and crystalline Polyester (core) is added to the nonwoven. These melt fibers z. B. type Melty 7080 (Unitika Ltd Osaka) show due to the crystalline Sheath structure a sharply defined melting point and an essential higher binding power than the amorphous binding fibers mentioned above. Such Fibers have a sharp melting point at around 160 ° C measured by DSC analysis, whereby an essential course of the Melt-coat polymer is not to be feared.

The proposed binding fiber increases the bounce of the nonwoven in addition and has good heat resistance according to the requirement the automotive industry.

The nonwoven fabric according to the invention can be manufactured in basis weights of 60 to 700 g / m ² , but preferably from 80 to 300 g / m ² , the thicknesses measured according to DIN 53855 T1 are adjustable and are usually between 1 mm and 15 mm, preferably between 2 mm and 7 mm.

The fiber strengths and lengths used can vary widely the titers and stacks mentioned, for example, are therefore in no way intended restrictive. Are common for the crimped shrink fiber Fiber thicknesses from 0.9 to 30 dtex, preferably 1.7 to 12 dtex, for the Binding fiber 1.7 to 17 dtex, preferably 3.3 to 12 dtex, for the mentioned fixed spiral crimped fibers and the 2-dimensional crimped Fibers 0.9 dtex to 30 dtex, preferably 1.7 to 12 dtex. The stack length is depending on the nonwoven production system used and moves in Range from about 20 mm to 150 mm.

It is understood that the nonwoven fabric can also be further refined by For example, a heat-activated adhesive layer is applied on one side.  

Explanations to the drawings

Fig. 1 shows schematically a conventional 2-dimensional (zigzag) - crimped fiber

FIGS. 2a and 2b show helically crimped fibers, Fig. 2a, the fibers in the raw state and

FIG. 2b shows the fibers in a thermally treated state.

Fig. 3 shows schematically the structure of a padded material, ( 1 ) the decorative layer, ( 2 ) the adhesive layer and ( 3 ) the padding material according to the invention.

Embodiment

It will be a mixture of fibers

20% melt fibers Melty 7080 (Unitika Ltd Osaka) 5.3 dtex 50 mm
30% spiral crimped shrink fiber Tergal X 403 3.3 dtex
50% Trevira 290 6.7 dtex / 60mm Hoechst / Trevira GmbH

manufactured, a card pile is created on a card and using a fleece layer a weight of 125 g / qm. Then the layers of Needled above and below and in a thermofusion oven at 180 ° C solidified and fixed. The final material thickness of 3 mm is determined using Calibration rollers set. The product is then wrapped in between and submitted to the lamination unit for lamination with the decorative fabric. Laminating is carried out using sprinkled and melted polyester powder.

The article obtained has an optically flawless surface, good Upholstery effect and no tendency to crease.

Claims (8)

1. Under-upholstery for decorative and / or covering material consisting of a needle-punched nonwoven made of textile fibers, characterized in that the textile fibers consist of a fiber mixture, the components of which consist of a) 10% -95% of a polyester fiber forming a spiral crimp, b) 5 % By weight - 50% by weight of a sheath-core bicomponent fiber and c) 0% -85% of a filler fiber mixture. 2. under-upholstery according to claim 1, characterized in that the sheath-core bicomponent fiber made of crystalline polyester (sheath) and crystalline polyester (core). 3. sub-upholstery according to claim 1, characterized in that the sheath of the sheath-core binding fiber has a melting point of 140 ° C. or more. 4. under-upholstery according to claim 1, characterized in that the, a spiral crimp forming polyester fiber, from a Polyester shrink fiber is made.   5. underpadding according to claim 1 and 4, characterized net that the, a spiral crimp forming polyester fiber, a Bicomponent fiber with side-by-side arrangement of the two polymers owns. 6. under-upholstery according to claim 1, characterized in that the filler fiber blend of spiral crimped, fixed polyester Fibers and / or two-dimensionally crimped fibers. 7. filling fiber mixture according to claim 1 and 6, characterized records that the two-dimensionally crimped fibers are natural fibers or synthetic fibers made of natural polymers, preferred Viscose fibers. 8. Filling fiber mixture according to claim 1 and 6, characterized records that the two-dimensionally crimped fibers are synthetic Fibers, are.