DE2004988A1 - - Google Patents

Description

Carl Freudeüberg January 29, 197o

694 Weinheim / Bergs tr. 2004 ^{988 0N} 547

Nonwoven-based crushed leather and process for making the same

It is already known to fold and natural leather Crumple, which can be made in various directions, with longitudinal or transverse folds to provide the one Form a regular or irregular pattern on the leather surface. The crumple effect can be increased by adding the leather surface is colored in different ways. The quality of the leather is practically not influenced by the crumpling. The crumpling serves only to create an optical effect in leather.

It is also already known to provide tissue with a poly and then to fold and crumple this two-layer structure again, whereby the surface film is broken again so that numerous wrinkles arise, which then also produce the effect of a crumple leather.

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Lately the so-called non-woven synthetic leather have become more and more important because - like natural leather - they are breathable and have a leather-like feel. It will therefore shoe upper leather is already made on the basis of non-woven synthetic leather.

For this purpose, a fiber fleece is impregnated with a coagulable binder. After the coagulation of this binder is then dried, resulting in a nonwoven fabric. The same is then on a surface still with a permeable film, in particular polyurethane film, provided.

The manufacture of the non-woven synthetic leather is in the book "Ullmanna Encyclopedia of Technical Chemistry", Volume 11, 196ο on pages 622 - 624. The subsequent application of a cover or coating film is described in I.e. on the Pages 624-627.

One could now think of one with such artificial leathers provided with a top layer on a non-woven basis To achieve a crumple effect by using the synthetic fiber leather, the first of all has a smooth top layer after manufacture, to crumple and crumple up.

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Immediately after crumpling the surface does indeed look a bit crumpled. As a result of the special properties of the substrate (non-woven synthetic leather) on which the If the cover film is on top of it, the wrinkles that have been introduced decrease or widen again after a few hours when worn.

So it is not possible with coated synthetic fiber fleece to achieve the desired permanent optical effect by simply crumpling. f

It has now been found that such a crushing effect is certain Measures can already be generated during the manufacture of the synthetic fiber substrate.

For this purpose, a fiber fleece is first of all heavily shrunk, preferably after needling. The area shrinkage should be at least 2o #, but preferably 5o f> . Even greater areal shrinkage is possible, though to produce the Knautschledereffektes g not essential. This fiber fleece is then impregnated first with a coagulable binder using known methods. The binder will be distributed evenly in the fleece.

The binder is then again displaced at certain points on the fiber fleece. Have these certain places preferably in the form of long irregular stripes.

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" ⁴ " 20CH988

The easiest way is to run over the impregnated fiber fleece with a pressure roller, which is a vein-shaped raised one Pattern bears. This vein-shaped pattern already imitates the folds in crumpled leather. Along the raised veins is now displaces the binding agent, so that a fleece is produced in which the binding agent is distributed unevenly.

In the extreme case there is no binding agent at all along certain vein-shaped lines, while there is overconcentration within certain areas delimited by the Jk veins. The binder is only coagulated when this state is reached.

Further treatment then takes place as usual. So you can first wash out non-coagulated binder components and then dry the fleece. This substrate, which initially feels like normal artificial leather and its properties Synthetic leather largely resembles, is then according to one of the known processes, e.g. according to the "counter coat process", coated with polyurethane.

As a result of the uneven distribution of the binder in the non-woven synthetic leather the surface will not be smooth, but rather have a vein-shaped mesh like that of the pressure roller is equivalent to.

In order to further improve the optical effect, this material, which is already clearly structured on the surface, can be used again

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can also be pressed and crumpled in the usual way.

example

A fleece consisting of

a) 7o io rayon and 3o $> polyester shrink fiber

b) 7o it polyamide and 3o $> polyester shrink fiber

with a square meter weight of 2oo g is needled, then shrunk. The area shrinkage is 45 - 50 $>. According to this, the weight of the goods after shrinking is 44o - 5oo g / m². Is impregnated with a commercially available, heat-sensitive colored Perbunan mixture (N 4 M from Farbenfabriken Bayer), with a wet absorption of approx. 15o #. The fiber fleece is then treated between two structured heated rollers as follows *:

The rollers have a vein-like pattern similar to the rollers is plotted sublime. The rollers are heated from the outside with gas (approx. 25o °). As a result, the mixture is first displaced in accordance with the pattern from the raised areas of the rollers and then precipitated. Temperature and speed are to be coordinated with one another. The material is then quenched in a cold water bath and non-coagulated binder or auxiliary agent is washed out. After the subsequent drying, a sheet is obtained which has the pattern of the rollers on both sides. Upper and lower gap one

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to be used in the same way (on conventional leather splitting machines). This way of impregnation results in a voluminous base material for further refinement (crumple paint).

This material produced in this way is then placed in the "counter coat process "coated with polyurethane. Edition: 50 g / m². The material is then slightly crumpled This process gives the material an irreversible crumple effect. This material can be used as a Synthetic bags, shoe materials and clothing leather are used.

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Claims (2)

Expectations 1. Crumpled leather consisting of a fiber fleece in which the binding agent is present in a non-uniform coagulated form and a top layer. 2. A method for the production of crushed leather according to claim 1, characterized in that a loose fiber fleece is first shrunk in area by at least 2o 96, then uniformly impregnated with a coagulable binder, then the binder along certain lines, which represent a vein-shaped pattern, is displaced, then the binding agent still present at the other points coagulates and then applies a top coat to the structured surface. OfMBtN. 109833/1998