DD157914A5 - METHOD FOR PRODUCING QUALITATIVELY HIGH QUALITY LEATHER AND ANIMAL HAIR FROM RAW MATERIALS - Google Patents

Abstract

The invention relates to a process for the production of high-quality leather and animal hair from Rohhaeuten whose hair is particularly suitable for processing in the textile industry. According to the invention, the appropriately trimmed raw hides to be treated are pretreated in a hydrated state in a non-swelling acid pickle broth or in a bran or Schrotbeize at 20-30 degrees C for 6-48 hours, after any neutralization or alkaline treatment in a new Exposed bath until the onset of hair permeability of the action of hair-loosening enzymes, then the hair from the skin, washed out and dried and subjected the Bloesse after Aeschern further known Arbeitsengengen. Sheep, rabbit and goat skins are mainly treated with this method. The quality of the hair is preserved, and also the skin part of Rohhaeute can be used for the leather industry.

Description

14 485 55

Process for the production of high quality leather and animal hair from raw hides

Field of application of the invention

The invention relates to a process for the production of high quality leather and. Animal hair from raw hides _and their hair is especially suitable for processing in the textile industry _o

In the processing of raw hides one always endeavors _s to achieve a maximum value of the finished products * One of the possibilities for this is _s in the leather production for the industrial use 'valuable hair with suitable methods . attract and use in this way both the skin as well as skin ":,

Under this aspect, the processing of the raw skins of sheep and rabbits presenting a particular problem ₅ because of the use of hair in the textile industry an appropriate quality must be guaranteed _e To obtain the 'rabbit hair is UbIiCh ₅ to shear the skins, "The quality of the hair obtained meets the requirements of the industry, the skin itself is no longer suitable for leather production *

"2 · -

To remove the hair from the skin, including the process of liming (Kaikens) is applied, the liming has a depilatory effect _s but relaxes next to the Paserstruktur the skin to some extent on.

The most commonly used ashes in industrial practice are chemical They hydrolyze the layer between the bellows and the outer skin in an alkaline medium and thereby loosen the bond between the two layers.

In order to reduce hair damage, numerous hair-conserving liming procedures have been developed, the common feature of which is the use of several baths.

According to HU-PS 143 247, the raw hides are first treated with an optionally buffered, low concentration, sodium sulphate solution and then in pure galactic hydroxide broth

According to DE-PS 1 288 728, the raw hides are subjected to biological hairstyles for obtaining qualitatively suitable hairs "in which loosening of the bond between bellows and outer skin proteolytic enzyme preparations are used." To increase the enzyme effect alkaline Vorquellen is used in many cases (ARA _S Röhm _s Darmstadt) "Similar procedures are also in DE-AS 1,233,530 and in the US-PS. 2,791-535, 3,076,749 and 2,857,317. However, these methods are used only to a limited extent, since the leather quality generally does not reach the quality achievable by liming and the methods are also quite expensive »

The known technologies, including enzymatic methods, are thus for the simultaneous production of rabbit hair usable in the textile industry and of. not suitable for leathers suitable for clothing * The situation is similar in the processing of

Sheepskins in which the optimal utilization of the hair and the skin could not be solved economically by the above-mentioned chemical and enzymatic methods or their combination ",

The aim of the invention is to develop a process for working up sheep _'s rabbit and goat skins, the hair can be easily removed from the skin with the short duration of treatment, the hair collected are of good quality and skin to Weiterverarbeitung.in the leather industry suitable is"

The invention accordingly provides a method for. parallel extraction of high-quality hair and of leather from raw hides suitable for processing in the textile industry. "It is characteristic of the process that the appropriately trimmed raw hides to be treated are hydrated in a non-swelling acid pickle broth at 20-30 ⁰ C pretreated for 6 to 48 hours ^ after any neutralizing or alkaline treatment in a new bath (a fresh liquor), if necessary, until the onset of hair-permeability ceases to exert the action of hair-loosening enzymes ^ then the hair is removed from the skin ' washes out and dries and subjects the nakedness to other known reprocessing processes after the liming

The sour pickle broth (the pimple) can, for example, have the following composition?

4 -

30-80 g / l sodium chloride 5-10 g / l ammonium sulfate

4-15 ml / 1 organic acid (formic acid, acetic acid, lactic acid, glycolic acid, etc.)

or inorganic acid (sulfuric acid, hydrochloric acid, etc.) 0,5-IjS g / l non-ionic surfactants «,

The liquor ratio '(PickelsRohhaut) is, for example, 15 liters of pickling broth per 1 kg of dry air rawhide *

Complex bite syetems can be used instead of the sour pickle, for example the bran broom or the pickle, which is common in horticulture.

Enzymes which function as depilatory enzymes are those proteolytic enzyme species which break down the skin membrane located between the ohorium and the basal epidermal cells in such a way that, above all, the hair becomes detached but skin fragments do not form. Such enzymes are commercially available and are used in leather insutation in pickling, loosening skin tissues, peptizing and improving the grip. "These enzymes include the proteolytic enzymes produced by mold fungi (Aspergillus oryzae, Asp * effesuSjs As'p. parasicitus, Asp _e Flvus), Peptide hydrolases, pancreatic enzymes, • for example, trypsin, also enzymes of bacterial origin (B ₀ mycoides, B "megatherium" Β _β mesentericus) "Mixtures of enzymes from pancreatic enzymes and molds produced from molds or from pancreatic enzymes and proteases of bacterial origin have also proved successful "

To loosen the hair, the enzymes are used in the bath in a concentration of 0.5-1.5% by weight, at the optimum pH for their effect, 25-35 ° C temperature and a treatment time of 10 16 hours ^ As appropriate

- 5 «.

Bnzympräparate be mentioned? Batan BT 2100 (Hoechst AG, FRG) _s Oropon (Rohm GmbH _s Darmstadt, FRG), Arazym ^ Rohazym (Rohm GmbH * Darmstadt, FRG) ₀ For the enzymatic pretreatment the preparations Eropal and Pereon (Rö'hm GmbH) have been used proved appropriate

If pancreatic enzymes are used for the enzyraatic treatment, then the skins are treated with a bath containing ammonia and / or sodium bicarbonate after acid picking,

The acid treatment preceding the enzyme treatment has its effect in that, as a result of the elimination of the intermolecular binding force, a pronounced loosening of the fiber structure of the collagen occurs. By this loosening of the structure, the enzymes can leach into the skin from the meat side in the course of further treatment and to the hair roots _f arrive without damaging the skin * Thus, by pre-treatment, it is possible to use the enzyme with a targeted effect, the Vorbehanldung allows the effect of the enzyme without damaging the hair practically to the loosening of the hair restrict"

With the inventive method both hair like skin of raw hides also can be used fully satisfying "from the resulting rabbit hair FiIz ₅ are made for the textile industry suitable threads and from these tissues while from the remaining end nakedness velor, lappa ·" can be made or wash leather "·

AusfUhrungsbeispieIe?

Bas inventive method is explained in more detail with reference to the following embodiments

6 -

Air-dry rabbit skins of a unit weight of 25O-3OO g are soaked in a manner known per se, fleshed off and then placed in a pickling broth of the following composition

60 g / l sodium chloride

5 g / l ammonium sulfate

6 ml / 1 formic acid

1 ml / 1 Hostapur CX (nonionic surfactant j manufacturer? Hoechst AG)

Liquor ratio 2 liters / skin temperature? 28 ⁰ Oo

The raw hides are agitated in a coiler trough in the above pickling broth for 5 hours and then allowed to stand overnight. "The next day, β ml / 1 formic acid is added to the pimpling broth, the skins are agitated for 3 hours and allowed to stand overnight treated skins are left on the box for one day «; ·. ,

Instead of the specified pickling broth, a pickling broth of the following composition may also be used:

60 g / l sodium chloride

4 ml / 1 formic acid

1 * 5 g / l sulfuric acid

0.5 g / l Tergolix A (Sandoz AG§

To reinforce the Pickelbrühe 4 ml / 1 formic acid and 1 g / l sulfuric acid are used.

After acidic pimples, the skins are treated 25 ⁰ O in the following bath?

'. - 7 -

8 ml / l 25% ammonia · 1 g / l fatty alcohol,

In this bath the skins are "moved long" for 2 hours. Thereafter the skins are treated at 30 ⁰ G in the following bath?

10 g / l pancreatic syni 5 g / l ammonium sulfate

1 g / l Lutensol AP-6 (BASF, FRG, nonionic surfactant)

In this ensemble the skins are moved for 30 minutes and then left to stand for 16 hours. Thereafter, the skins are dewatered by centrifugation and hair-dried by hand or by machine

The recovered hair is washed out in pure, warm water. The washing machine is changed several times. ₉ The hairs are centrifuged in each case. The nakedness is limed and then fed to the known operations of the leather industry. "

Example 2

Well softened sheepskins that have been freed of coarse impurities or washed completely clean are treated in a pimple bath of the following composition.

60 g / l sodium chloride

6 ml / 1 acetic acid 1.5 ml / 1 lactic acid Ij5 ml / 1 sulfuric acid Ij5 ml / 1 Hostapur GX. . ·

The plotting ratio is 20-30 liters / 1 piece of skin, · it depends on the length of the wool _P Treatment; is at

- 8th

28 ⁰ C in a coiler trough · The hides are moved for 5 hours, then allowed to stand over Eacht, on the following day for 3 hours moved «The entire pimple time is 6-24 hours« ·

After the pimples, the skins are left on the box for a day. Then the pickled skins at 30 ⁰ G are held for 2 hours in a bath of the following composition s

6 ml / 1 25% ammonia

4 g / l of matrium hydrogen carbonate Ij5 g / l fatty alcohol,

"

pie in this way pre-treated skins are at 30 ⁰ G IO hours allowed to stand in an enzyme bath of the following composition t

6 g / l pancreatic enzyme

5 g / l ammonium sulfate

1 g / l nonionic surfactant _e ';

After the enzyme treatment, the skins are centrifuged and the wool is removed. The washing of the wool and further working up of the pelt are carried out as described in Example 1.

- 9. -

Claims (1)

CJ / 33: Ϊ r "i η du ge η a η ρ s r uch t l _s whose hair is _e process for the production of high quality 'Pi he η hair and leather before solely of skins suitable for processing in the textile industry, characterized in that it is not the raw hides to be treated., suitably fleshed in the hydrated state in a - swelling acidic Pickelbrühe pretreated at 20-30 ⁰ C for 6 to 48 hours _t . Then, after a disturbed or neutralized alkaline treatment in a new bath until the onset of hair-permeability, the action of hair-loosening ensyra pauses The hair is removed from the skin, washed and dried and * · '.' .,
• "subjecting" the nakedness to other known operations after liming, Process according to item 1, characterized in that a bath containing 30-80 g / l of sodium chloride, 5-10 g / l of ammonium sulphate, 4-15 mmol / l of inorganic or organic acid and 0 _s 5-1 is used for sour pickling _s 5 g / l of nonionic surfactants, 3e 'method according to point 1 _? characterized in that one used instead of the sour pickle bran stain or Schrotbeize 4e procedure according to point I ₅ . characterized in that the enzyme used as a depilatory enzyme is pancreatic enzymes, proteolytic enzymes produced by mold fungi or enzymes of bacterial origin or mixtures thereof, 5e method of item 1 or 4, characterized in that the skins in 0.5-1.5 wt _e in - treated containing% enzyme baths 10 to 16 hours " - 10 6, "method according to item 1, characterized in that the skins are neutralized after acid pickling in a bath containing ammonia and sodium bicarbonate or made alkaline. 7 * Method according to item 1, characterized in that the enzymes selected for the treatment of the skins are used at the optimum pH value for unfolding their effect. & * Method according to item 1, characterized in that sheep skin or rabbit skins are used as rawhide *