DE1635492A1 - Process for the production of binder-bound nonwovens with a smooth surface - Google Patents

Description

CARL FEEUDENBERG 3-1. 1966

Weinheim / Bergstrasae (ON 4-37)

Method for Herateilen τοη binder-bound Nonwovens with a smooth surface

The invention relates to a method for producing a bonded nonwoven fabric with a smooth surface like high tear and abrasion resistance.

It is already known to use nonwovens with a binder, in particular Impregnate latex and the resulting wet

then to dry and then on

Temperatures of about 120 ⁰ C to heat. The binding agent vulcanizes in this way. In this way, an receives a nonwoven material such as is commercially available under the name VLIESELDiE, for example. Details of the production of such nonwovens can be found in the book "Eextilverbundstoffe" by Dr. R. Krftma, VEB-Verlag Leipzig, 1963 .. · '

It has now been found that the properties are different Vliesatoffe can improve if you combine the fleece with a

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so-called sensitized latex impregnated. Sensitized latex is understood to be a latex to which coagulants have been added which, when a certain temperature is reached, cause the latex to coagulate. Lan has already proposed; To use sensitized latices for "impregnating fiber webs. These are mixtures with which the web is first impregnated at room temperature and then the wet fiber / structure is ^{heated to at least 60 °} C. When this temperature is reached, the latex coagulated In the form of many small rubber balls, under the microscope the binder looks like caviar or an agglomerate of pellets.

While so far only those sensitized latices have been used for impregnating nonwovens, which are at least had to be heated to 60 ° C. in order to initiate coagulation, low-sensitized latices are used according to the invention. With them, coagulation already occurs at temperatures of +5 to + 35 C. For this reason, the latices with the Coagulants must be stored at lower temperatures.

These latices are first beaten into foam by the method according to DP 910 960. This cold foam is converted into a loose fiber fleece using the known foam process with the aid of rollers pressed in. The wet fleece thus impregnated is then allowed to run through under an infrared radiator, with very

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heating up to the coagulation point is achieved quickly. Of course, you can also use a conventional drying chamber with hot air instead of an infrared heater. It is only important that the heating to the coagulation point takes place as quickly as possible. After coagulation, it has hitherto been customary to run the wet fleece through cold rollers, with excess binder and water being squeezed out of the fleece. According to the invention, however, is allowed to pass through a steel roller pair, the wet nonwoven fabric, wherein the temperature is on the roll surface about 10O ⁰ C. The pressure in the nip is around 20 - 60 kg / cm. However, these values can be exceeded. The hot-calendered fleece is then dried at temperatures of 120-130 °. Vulcanization occurs at the same time.

The combination of the features according to the invention, i.e. impregnation with a low-sensitized binder in foamed form, rapid coagulation and subsequent hot calendering, makes it possible to produce nonwovens whose tear strength is 35-50; i higher than the tear strength of nonwovens produced in a known way. They also have a smoother surface and are therefore also very resistant to abrasion. The attached flow diagram shows an embodiment of the invention,

Example:

A fiber fleece consisting of polyamide fibers with a length of 40 mm tinct 3 den. is impregnated with a mixture

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Composition; in foam form:

100 tIe. Perbunan N4M
5 "zinc oxide
4 "non-biogenic wetting agent (trade name

LA 140) 2 "cation-active wetting agent (trade name

Silastan DG) 1.5 "formaldehyde

4 "ammonium chloride as a cooling agent 200 "barrel

such that a fiber: binder ratio of about 50: is achieved.

The fleece impregnated in this way runs under infrared radiators, causing the rubber to coagulate on the fiber. The wet fleece is then run through a pair of steel rollers, the temperature being measured on the roller surface is about 100 °. The pressure in the nip is 50 kg / cm. Then it is dried at 130.

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Claims (1)

Claim; Γ " Process for the production of binder-bound nonwovens with a smooth surface and high tear and abrasion resistance, characterized in that a fleece is impregnated with a low-sensitized tissue binding agent = dispersion, the binding agent adjoins the impregnated fleece quickly coagulates, then the sheet structure underneath Pressure calendered hot and then vulcanized above 120. Blank page