DE19804418B4 - Voluminous fabric for padding decorative layers - Google Patents

Abstract

Underpadding for a decorative and / or upholstery material consisting of a needle punched nonwoven fabric using a fiber blend comprising a filler fiber blend, latent crimp fibers, and bicomponent core / shell melt fibers;
characterized,
The bicomponent core / sheath type melt fibers consist of a crystalline sheath polymer and a crystalline core polymer,
That the melting point of the crystalline sheath polymer is at least 140 ° C, and
That the components of the fiber blend of a) are 10% to 95% of a spiral crimp forming polyester fiber, b) 5% to 50% of a sheath-core bicomponent fiber, and c) 0% to 85% of a filler fiber blend.

Description

The The present invention relates to bulky underpadding fabrics of decorative layers. Such layers for Unterpolsterung finds eg in the living area, for example under textile wallpapers, a voluminous Emphasize structure of the decor fabric and improve the heat insulation, in upholstered furniture, to the underlay under the furniture fabric, for example, to make the side armrest areas a little more voluminous and in the vehicle and truck sector, for padding the seat upholstery, and the lining materials in the interior area, for example of interior door panels, Instrument panels, in the headliner area and in the floor area.

at The decorative materials used are as required mostly to substrates from the group of textiles, such. tissue (including car seat cover fabrics), knitted or crocheted fabrics, scrims or nonwovens, or from the group of foils or imitation leather, or from the group the leather. Such decorative materials serve the surface of objects, such as walls upholstery or vehicle interior to make handsome. As it is here, however, usually more or less flat or two-dimensional Entities act often exists the need, to make the decorative layer a bit more voluminous, especially as an oversight a hard surface with the aforementioned decorative layers unsightly can be or cause an unpleasant feeling when touched.

It is known for such a purpose so-called to use, which usually off a foam composed with, the high frequency fissile favorable Fibers, and possibly a cotton nettle is needled. The decorative layer is welded using high-frequency technology with the welding wadding. These However, technology requires polymers with dipole character, which is why the decorative layer at least partially PVC or other halogen or pseudohalogenhaltige Must contain polymers. Due to the environmental discussion around halogen-containing polymers today this technique is hardly used anymore.

A so far often padding used is a thinner, e.g. 2 - 8 mm thicker Foam. Advantage of foam padding are undoubtedly the low price, the pleasant softness, which are precisely adjustable is, as well as the excellent resilience too after repeated exposure. This foam was preferred connected by flame lamination with the decorative fabric. For this was a 0.2 to 1 mm thick foam used as an adhesive by this liquefied by gas flame and bonded the decor and foam padding layers. This process is due to the flame treatment of the foam The resulting toxic gases have come under criticism and today often against more environmentally friendly laminating processes have been exchanged.

One Another serious disadvantage of the foam is the raw state insufficient flame retardancy After the example in the automotive sector required Schwerflammbarkeitsnorm MVSS 302. Flame retardancy can only be achieved by the addition of flame retardant chemicals be achieved. This is reinforced but the anyway with foam not insignificant so-called. Foggingeffekt, so the precipitation of plastics volatile substances on the discs, not alone with new vehicles. Fogging is not only unpleasant, because it forms a milky veil on the vehicle window, but also affects the Traffic safety, as at night by the lights more responsive Vehicles glare and reflections occur.

One Another problem that can occur with foams is that poor aging behavior. With increasing vehicle life can be foams because of the frequent Cold / heat Fluctuating Aging and aging in conjunction with strongly changing humidity be destroyed before the end of vehicle life.

Out This reason has been around for some time for alternatives to Foam padding sought.

common is the use of pure needled nonwovens, which are made of unmixed Synthetic fibers or made of garnetted fibers can exist, and on carrier materials if necessary like gauze or spunbond can be needled. Such nonwovens have the disadvantage that the Achievement of the required resilience of the Use of an elevated grammage necessary, because the required property of good resilience, too after repeated exposure, only through the use of materials high density, so by a high in relation to the material thickness grammage can be achieved. An increase However, the density causes the negative effect that the required softness can not be achieved compared to the foam.

In the EP 763418 A2 (Daimler Benz) describes a method for producing a multilayer web of outer fabric and an underlying nonwoven fabric. The nonwoven fabric mentioned in this document must have a high standing nonwoven fabric Be fiber content, which is additionally stabilized with binder fibers. As the production process for the nonwoven fabric Dilourisierungsverfahren or Nähwirkverfahren or the so-called Strutoverfahren be mentioned. The binder fiber-containing, preconsolidated nonwoven fabric is thermally treated in a thermofusion zone and calibrated over tapered pitch guide tapes. Subsequently, a lamination can take place with the decorative material in the same line.

In the right of protection is neither more specific to the nature of the binder fibers, even more specific to the nature of the carrier fibers received. One mentions For example, only the use of a "bicomponent binder fibers, in the case of the two thermoplastics of different melting point, z. B. 140 ° C and 220 ° C, in concentric arrangement with the lower melting plastic outboard. "In the case of the carrier fibers mentioned one the application possibility of tensile fibers or the use of polyester fibers of certain fiber dimensions, it must be assumed that they are fibers with a usual and mainly common two-dimensional crimp structure is.

Needle- or knitted nonwoven fabrics of such fiber blends usually show various disadvantages, which is the use in particular for padding for parts with difficult contours or shapes in question. So tend Such nonwovens when bending around sharp edges or in three-dimensional Forming for the formation of creases, which are characterized by the decorative material and the optics of the surface are unacceptable Way influenced negatively.

Be explained This can be caused by too much bleeding of the amorphous enamel shell the biko fiber, reducing the relative fiber movement in the nonwoven fabric highly limited becomes.

One Such behavior is also called "rolling behavior" appropriate examination it happens in such a way that one the two ends of the pattern are U-shaped but without folding them. Then the ends are parallel, but shifted in the opposite direction, so that at the bending point gives a movement. It is judged whether the movement smooth, round (= clean unwinding) or if there are creases.

Of the Use of these conventional fibers still requires the use one raised Basis weight, because the required property of good resilience even after repeated Strain, with such fibers, only through the use of materials high density, so by a high in relation to the material thickness grammage can be achieved. This is a second disadvantage of such Substances opposite Given foams, namely the relatively hard one Lost goods, which is necessarily accepted, but is in need of improvement. The high basis weights of such Materials in conjunction with the mentioned relatively slow-producing Manufacturing process Dilourization, stitchbonding or the so-called. Strutoverfahren, also high prices of such items.

The mentioned higher grammage also affects the aspiration of automotive engineers contrary, by weight savings the fuel consumption of the Lower vehicle.

Of the Unterpolsterungsstoff invention does not show these disadvantages. Here are the characteristics of surface smoothness, good Softness, good resilience, too after repeated loading, good rolling behavior (consequently no crease formation), good spring elasticity, low density, low weight, low price, ideally united in itself.

Additionally offers the Unterpolsterungsstoff invention the advantages of the extremely low fogging tendency, as well as the fulfillment the heavy flammability standard MVSS 302 without any addition of flame retardants.

Of the Unterpolsterungsstoff invention is produced by the needle-punching process, as for example in the book "Nonwovens" by the author "Lünenschloß" Georg Thieme Verlag Stuttgart, 1982, on pages 67 to 103 and 122 to 142 be subjected, and subjected to a temperature treatment, as on the Pages 215 ff. Of the same book is described.

P 03-220354 A describes a fiber mixture, which consists of two components consists. The binding fiber is a bicomponent type amorphous enamel coat. This amorphous cloak is already melting a temperature which is significantly lower than the temperature, which is necessary to activate the latent crimping of the filling fiber is.

to Activation of latent crimping the fleece is subjected to temperature. Due to the low Melting point of the amorphous shell component of the melt fiber the mantle at the activation of the latent crimp necessary temperature already long ago melted and thin. He is therefore very easy and fast to get around by just the activation formed fine ripples and masked by it these.

The invention is based on the idea by shifting the melting point of the sheath polymer toward the latent crimp activation temperature, the molten sheath upon activation is not as molten as in prior art materials. This is achieved by the measures listed below.

The contained according to the invention Binder fiber is made of crystalline PET core and one too crystalline PET coat. This coat shows thereby, in the difference to JP 03-220354 A, a melting point, on the one side is defined and the other higher is lower than in the known, the prior art, amorphous types. It is within the range of the activation temperatures for the latent ripples, i.e. at 140 ° C and higher. This means that, in contrast to JP 03-220354 A, the jacket at the time of crimp activation is viscous and therefore not around the curl just formed sets. The introduced by the activated, originally latent ripples Properties of the nonwoven fabric become when using the fiber mixture according to the invention not impaired.

Of the produced according to the invention Nonwoven fabric stands out from the prior art in such a way that the after activation of the latent crimp trained spiral crimping not masked by the enamel coat of the binder fiber, but is free and active. Thus, a Eindrückverhalten, the results similar to foam. This effect comes through the trend, environmentally friendly foam to replace recyclable nonwovens in the automotive sector.

JP 08-158223 A describes the use of latently crimped Fibers, which also used here for solidification of the web Melting fiber has a lower melting point. The curled fiber has a latent crimping from 5-25 sheets per 25 mm. This is thus significantly lower than that of the nonwoven fabric according to the invention. The solidification is done in a manner similar to JP 03-220354 A described. This results in all the disadvantages of JP 03-22035 A.

JP 07-324268 A describes the use of a bicomponent melt fiber with an elastomeric fiber core. The thus obtained nonwoven fabric has Although also elastic properties, but these are on Based on another technical solution. Elastic properties Here are purely through the fiber core of the melt fiber in the fleece brought in.

Of the Nonwoven fabric according to the invention gets its elasticity however, by the interaction of spirally crimped after activation Fibers and crystalline melt fibers which the aforementioned resilient Properties of spiral-curled Do not interfere with fibers. Likewise, a compression of the surface with the activation of the latent ripples which would not be observed in JP 07-324268 A.

EP 0372572 A2 is a polyester polymer derived from a mixture of terephthalic acid and glutaric acid or its derivatives, which can be used as a low melting and low shrinkage binder fiber or filament.

Of the Unterpolsterungsstoff invention consists mainly of polyester fibers, which is the property have to shrink when exposed to heat and thereby a spiral crimp train. For example, bicomponent fibers are suitable for this purpose of the side-by-side type, which have the property, as delivered a lower crimping intensity and / or another crimping characteristic to possess as after, for example, integrated into the process Heat treatment. 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 of polyethylene glycol terephthalate in one half and polybutylene glycol terphthalate in the other half. at When exposed to heat, the two halves of the fibers shrink differently, similar to one another Bimetal, thus forming a denser crimped three-dimensional structure. The number of curling bows can in such fibers, for example, originally from 10 to 13 sheets / inch on 50 - 70 Bows / inch change after the heat treatment. The result is natural a shrinkage and concomitant densification of the nonwoven fabric. Such a shrinkage of the nonwoven fabric causes a homogenization of the Surface image, since the nonwovens and needle processes caused by thin spots, by reduces the contraction caused by the shrinkage of the nonwoven fabric become.

such Fibers can also in the original one State a conventional one 2-dimensional crimping possess, with the spiral crimping only after the described Forms heat treatment.

Also Fibers, which after thermal treatment, a spiral crimp without being able to form said biko structure are suitable.

Through the use of said fiber and the rolling behavior of the nonwoven fabric is significantly improved. This could be explained by the fact that, due to the shrinkage and the three-dimensional crimping, the fibers are tangled in the fleece and not, as in the two-dimensional crimped fibers mentioned, a preferential direction usually results in the carding direction. As a result, the padding material according to the invention exhibits a rather isotropic rolling behavior, which causes any creases to form any longer.

Spiral-crimped fibers additionally cause the vate to give it a foam-like character. While a nonwoven made of 2-Dimensionally crimped fibers, even if he, as in the EP 763418 described, consists of at least 20% perpendicular to the surface oriented fibers, and binder fiber contains, and is soft, when squeezed only after about two-thirds of the way a noticeable resistance, ie a cushioning effect, sets the inventive

nonwoven made of spiral-curled Fibers already after at most 20% of the way the deformation counteracts considerable resistance, but without being hard. This characteristic is similar to the of the foam very much. Furthermore, the spiral-crimped fiber causes a better resilience, too after repeated loading, as known underpadding materials with conventional 2-D crimped Fibers. Explained could be this effect in that the helically crimped Fibers as three-dimensional, sphere-like aggregates in the nonwoven fabric and not, as with 2-dimensional crimped fibers in a plan or vector Orientation.

These Benefit to that the Material density and therefore also the basis weight by at least 15 %, usually but at least 20 - 50% across from the padding materials are reduced from conventional fibers can.

Out cost reasons can the above-mentioned helically crimped Bicomponent shrinkage fiber partly due to already unfixed spiral crimped fibers or by conventional, 2-dimensionally crimped fibers preferably Polyester, but also by fibers of other polymers, or by Natural fibers are replaced. A minimum proportion of about 10% by weight spiral-crimped However, bicomponent shrink fiber in the nonwoven fabric is necessary.

such fixed spiral crimped Fibers are for example under the name Dacron T 88 of available from Du Pont de Nemours, Wilmington. As an example of one, 2-dimensional ruffled Fiber is the Trevira Type 290 of Trevira GmbH mentioned.

One essential component of the padding material according to the invention is the binder fiber in a weight fraction of the nonwoven fabric of 5% - 50%, preferably 5% - 30 %. A consolidation by the widespread amorphous bicomponent fibers consisting of a crystalline PET core and an amorphous cladding from a copolymer of terephthalic acid and isophthalic acid and Glycol (type Melty 4080, Melty 3380, Melty 2080 all Unitika Ltd. Osaka) the disadvantage that straight in such amorphous types, the melting points are not unique and the softening of the fibers already starts at 70 ° C (Glass transition temperature, or here: Realization temperature). A continuous increase the temperature above this glass transition temperature of 70 ° C has a continuous weakening the thermal stability of the nonwoven fabric entailed and would this one for make the use in the automotive sector unsuitable. Furthermore, would be at the usual Shrinking temperatures of the spirally crimped bicomponent shrinking fiber from 160 to 190 ° C the amorphous melt shell liquefy so that the melt is closed around the spriral-curled Bicomponent shrink fiber lays and their positive properties for the most part Neutralize part.

According to the invention Problem solved by that to Solidification of a sheath / core fiber of crystalline polyester (sheath) and crystalline polyester (core) is added to the nonwoven fabric. These Melt fibers e.g. of the type Melty 7080 (Unitika Ltd Osaka) due to the crystalline shell structure a sharply defined Melting point and a much higher binding force than the above mentioned amorphous binding fibers. Such fibers show a sharp melting point of the jacket at about 160 ° C, measured by DSC analysis, with no significant bleeding of the melt-shell polymer to fear is.

The proposed binder fiber reinforced the bounce of the nonwoven fabric in addition and causes a good heat resistance according to the requirement of Automotive industry.

The nonwoven fabric according to the invention can be produced 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 thicknesses and lengths used can vary widely, and the titers and stacks mentioned, for example, should by no means be restrictive. Fiber thicknesses of 0.9 to 30 dtex, preferably 1.7 to 12 dtex, for the binder fiber 1.7 to 17 dtex, preferably 3.3 to 12 dtex, are common for the sprial-crimped shrink fiber, for the abovementioned spirally crimped fibers mentioned and FIGS -dimensionally crimped fibers 0.9dtex to 30 dtex, preferably 1.7 to 12 dtex. The staple length depends on the fleece production plant used and ranges from approximately 20 mm to 150 mm.

It understands that the Nonwoven fabric can also be further refined by, for example, one-sided a heat-activatable Adhesive layer is applied.

Explanations to the drawings:

1 schematically shows a conventional 2-dimensional (zig-zag) crimped fiber

2a and 2 B show spiral-crimped fibers, wherein 2a the fibers in the raw state and 2 B shows the fibers in the thermally treated state.

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

Embodiment:

It will be a fiber blend
20% melt fibers Melty 7080 (Unitika Ltd Osaka) 5.3 dtex 50mm
30% spiral crimped shrink Tergal X 403 3.3 dtex
50% Trevira 290 6.7 dtex / 60mm Hoechst / Trevira GmbH
produced, created on a carding a card stock and set by means of a nonwoven a weight of 125 g / sqm. Then the layers are needled from above and from below and solidified and fixed in a thermofusion oven at 180 ° C. The final material thickness of 3 mm is set by means of calibrating rollers. Subsequently, the product is wrapped and presented to the laminating unit for lamination with the decorative fabric. Lamination is carried out by means of scattered and melted polyester powder.

Of the received article has a visually impeccable surface, good Upholstery effect, and no tendency to wrinkle formation.

Claims (4)

A upholstery for a decorative and / or upholstery material consisting of a needle punched nonwoven fabric using a fiber blend comprising a filler fiber blend, latent crimp fibers and bicomponent core / shell melt fibers, characterized in that the bicomponent melt fibers are the core / shell - consist of a crystalline sheath polymer and a crystalline core polymer, - that the melting point of the crystalline sheath polymer is at least 140 ° C, and, - that the components of the fiber mixture of a) 10% to 95% of a, a spiral crimp forming polyester fiber, b) 5% to 50% of a sheath-core bicomponent fiber; and c) 0% to 85% of a filler fiber blend. Underpadding according to claim 1, characterized in that the cladding and the core of the crystalline bicomponent fiber Polyester exist. Underpadding according to claim 1, characterized in that the Füllfasermischung made of spiral-curled, fused polyester fibers and / or from two-dimensionally crimped Fibers consists. Underpadding according to claim 1, characterized in that the fibers with latent crimping made of spiral-curled, made of fixed polyester fibers and / or two-dimensional crimped Fibers consists.