DE1635497A1 - Process for the production of soft, washable and dry cleanable nonwovens containing thermoplastic fibers - Google Patents

Description

Carl Freudenberg ": '. ^K ^ 3 * August 1967

Weinheim / Bergstrasse "; Dr.Z / Sch ON

Process for the production of soft, washable and dry cleaning resistant: thermoplastic Fibers: containing nonwovens:

It is already known to make fibrous sheet-like structures - such as nonwovens - flame-resistant by post-treatment with a solution or dispersion of paraffins, waxes, fatty acids, post-chlorinated polyvinyl chloride and antimony trioxide make it suitable "If you want to, which are, for _o example, according to the British patent specification 1 o5'5 187 produced non-woven fabrics, particularly those, which are under the designation spin-fleeces or _o spun-bonded fabrics commercially, flame-resistant, so resulting considerable difficulties,

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Medium-bound nonwovens are due to the binding emit te lan ** partly in a certain sense already provided with a flame retardant. They are more difficult to ignite than a corresponding one binder-free fiber fleece. However, has a Once such a flat structure has caught fire, the binding agent it contains melts, it is no longer there possible to start the fire by hitting with your hands or throwing it over of blankets to-erase, moreover would when pressing Such a tissue also melts onto the skin of the The wearer and cause severe burns.

So although binder-bound nonwovens are relatively are flame retardant, on the other hand, if the flat structure has caught fire, the extinguishing is ins- ' especially difficult because of the dripping, molten and also burning binding agent «,

The invention now relates to a flame retardant composition with whose help the melting and dreaded dripping of the Binder is avoided even if the fiber sheet through prolonged contact with an open flame Caught fire ·. .

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As mentioned above , ventilated nonwovens should be used in quantities of binding agent of 8 - -fo $, '. on the overall weight, -AbUotu -Al® IttndemittBl 'fcennmen mainly -iBa-ture «- and. "Synthetic rubber" as well as itc ^ yiatha ^ e ± n-> question "If you want to. Now T>: Ei a mouthpiece ^; Hiesstoff-prevent · that binder 'melts and drips off during drying ^ so you proceed as follows. Fleece is initially only ' impregnated with about half of the required quantity of raw material (i.e. latex or terylate resins).: · - ·: - "" ■ "■ -"' ■■ '■

Then dried and impregnated according to a second operation with einer'Dispersion whose Hauptbestandtexle POlyTrinylidenchlorid / jund Äntimontrioxyd _o are the same time, it must mixture contain brighteners, as otherwise, the resulting sheet would have a schlschte ■ iLichtbeständigkelt ο.

The second impregnation takes place under special conditions, For clarification, reference is made to Figures 1 and 2

In Figures 1 and 2 , a so-called foulard can first be seen, as is customary for impregnating fiber fleeces.

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ift 21.7 000) from two rollers., - which can also be coated »The lower roller is immersed in a liquid that contains the impregnating agent Foulard rollers, then at the same time binding agent liquid is pressed into the fleece over the wet felt covering *. .. ■ ■

The second impregnation is shown schematically in FIG ο At A the already pre-consolidated fleece runs through the gap of a padder “The lower roller dips into a A dispersion, the main components of which are polyvinylidene chloride and antimony trioxide, so these Beatand parts get there (together with optical brighteners) into the fleece,

'This is then passed over hot steel rollers C (so-called cylinder dryers) for drying. (D was used to designate auxiliary rollers that facilitate the guidance of the fleece B) “The decisive factor now is that the cylinder rollers. G rotate faster than the rollers of the padder A ₀ In this way, the fleece is stretched, while its width is reduced at the same time »

This is shown in the accompanying Figure 2, which is a schematic Top view shows, reproduced “Marr sees how there

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the Balm B; between the padder A and the drying rolls C elongated and thus narrowed. After this Passing the drying rollers C, the fleece is dry, Ss becomes but then again moistened in a foulard E »(At Foulard E immerses the lower roller in pure water) „■ Then is in the chamber F in a so-called tenter frame dryer again dried. When passing through the drying chamber F, however, with the help of the clamping frame, the The width of the fleece is pulled apart again so that it gets its original width again0

This re-moistening in the Foulard E and the drying of the stenter frame in the chamber F is clearly shown in FIG take, you can see how the wet in the foulard E. Fleece is pulled apart again.

As a result of the double delay (first longitudinally and then in the transverse direction) after the second impregnation, the binder in the fleece is broken several times, so that even at high Binder proportions make the end product very soft and textile-like handle., The following example gives an embodiment of the invention again;

A according to example 2 of the English patent specification 1 o55 produced fleece with a weight of 30 g / m is with

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with an acrylate resin (trade name PRIMAL ·) impregnated in such a way that after the subsequent drying the weight

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rises to 50 g / m »A fleece impregnated in this way is then re-impregnated with the following mixture:

fixed fluid Ic ο 2oo 5o loo 2 CVl 2.5 2.5 o, 25 1 487

Diofän 23o surcharge Blankofor Hösch EP 35 stabilizer emulsifier water

Aerosil ', 4.78

The surcharge mentioned in the above composition in turn consists of

solid liquid Sb ₂ O ₅ 48o

pigment

Distributor A 2o 66

Water 453

The impregnation with the aid of the mixture mentioned above takes place in a felt padder. Both rollers are pressed against each other in such a way that the fleece weight after drying of

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5o increases to 58 gr / m. The drying takes place first on 3 hot metal cylinders "The metal cylinders rotate at a speed of 45 m / min, while the padding rollers only revolve at a speed of 30 m / min." In this way the originally l _r 7 © m wide fleece web is so drawn in length that its width is only Ioο cm. ..- ■ -.,

After leaving the cylinder dryer (surface temperature 14o °), the web is again in the padder E. Water-soaked The wet fleece then runs into a 'tenter · »· dryer Ψ with a needle or« clip chain «, at a temperature of 14 'O ° the fleece is now stretched back to 17ο cm,

One that has been dried in this way with a double delay Fleece is not only flame retardant, it is also very soft

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Claims (1)

for the production of soft, washable «and. ' pure!" "nonwovens containing thermoplastic fibers" in which the thermoplastic components "at do not melt in contact with an open flame, characterized by the fact that the thermoplastic fiber containing fleece initially only pre-binds with polyacrylate, then: dries and then with an aqueous dispersion: re-impregnated, which consists of approximately equal parts of poly- vinylidene chloride and antimony trioxide along with small amounts optical brighteners, then un longitudinal stretching the wet fleece dries, re-moistened and finally, now under cross-bracing, dried L e r s e i t e