SU38249A1 - The way of tanning - Google Patents

Description

The new invention aims to improve the combined tanning both by mechanical means (juice with drum) and by chemical means (tannids of oak extract and sulphite-cellulose extract).

A new method of tanning with preparatory operations is carried out as follows.

Soaking-up to full water cut, according to the regime set forth in the normal procedure TS.NT.S. The leather industry (see collection number 2 for 1933). Dehairing is done while preserving the wool in one of the following options.

1st option. Golding is done in a battery system of three ash pits. The liquid of the head ash pan, daily before the arrival of a fresh batch, is supported by lime mortar based on the lime weight from the pair weight of the raw material entering the ash pan. Sodium sulphide is given in the amount of 0.4 g per liter. The fixing of the two other ash pits is done by overflowing 1/3 of the ash liquid from the tank into the tank, when the 1/3 tail ash pan is drained into the sewer system. Continued (96)

Ness zolki three days. The temperature of the ash liquid in the tail 23 °, an average of 25 ° and head 27 °. Liquid coefficient-4.

2nd option. Processing for 3-4 hours in the drum with a solution of sulfur soda concentration of 1 in a liter, a temperature of 20 ° and a liquid coefficient of 3.

Rotation of the drum is given periodically every 5-10 minutes. The skins are then hung in an ash pan for a solution of pure lime, containing not less than 15 grams per liter. Liquid coefficient 8. Temperature 27 °. The duration of ashing is at least 48 hours with bulkheads at least every 6 hours.

3rd option. Treatment in a flat drum (liquid coefficient 3) waste milk of lime from the previous batch for 1 hour, at a solution temperature of 22 °. The descent of the waste liquid, giving fresh lime milk (liquid ratio 3) with lime content from the fresh weight of the raw material. The processing time is 10 hours, with a gradual increase in temperature from 22 to 27.

The skins are then discharged from the drum and dumped onto the spread floor in a tank on the ash liquid from the previous batch, where lime is previously added from the fresh weight of the raw material. Liquid coefficient4. After 8 hours, the bulkhead, and after 25 hours from the start of the process, unloading.

Throw on a fresh ash liquid spreading in the tank, the liquid coefficient 4. The temperature of 27 °. Lime 7 / o from the pair weight of raw materials.

After 36 hours of bulkheads, after 48 hours of unloading and feeding for the wool cutting. Ash liquid serves for two batches. Wool cutting is performed on a machine with a dead end on the edges of the decks.

After the wool has been removed, the first face is thoroughly cleaned, rinsing in a drum or a long-haul on running warm water at a temperature of 22-25 °, for 30 minutes, and a second wash - in a mask.

De-clearing is performed by complete control of the process with phenolphthalein by cutting. The sample should not give a red color. Disintegration may be carried out according to one of the following options.

1st option. Desalting is performed using molasses, glucose or molasses in a tank by weight, at a rate of 0.8 ° / (weight of the mole. Temperature 38 °, liquid coefficient 8. Drainage time of 12 hours when the system is established. Golier is hung by 1/3 of the old liquid and 2/3 fresh. A freshly-filled vat with molasses usually decolourizes slowly.

2nd option. Disintegration is performed in a rotating apparatus, but it can also be carried out in vats by weight on a weak solution of hydrochloric acid with a concentration of 1 g of HCI per 1 liter with the addition of ammonium sulfate after 1 hour, in an amount of 0.5 by weight of the volume of the liquid. Liquid coefficient in drums-4, in vats-8. Processing time not less than 24 hours

In the absence of molasses and ammonium sulfate, Desalting can be performed on hydrochloric acid alone.

For this, in a plate or suspension drum with a liquid coefficient of 3 or in a launch with a liquid coefficient of 4, the solution pH is maintained in small portions for a period of 20 hours in a diluted form, hydrochloric acid, the pH of the liquid is maintained throughout the process. 6-6, 5.

After de-treating, the pedestal is thoroughly cleaned over the face with a constant inflow of water on the Leidgen machines or manually with a dead end on decks with washing with a temperature not lower than 25 °.

Tanning is produced by a mixture of tannins of oak with sulphite-cellulose extract in juice and in a drum in purely oak extract. The consumption of tannins for whole skins is 27 / o by weight of the mole, of which about 1/3 are tannides of the sulphite-cellulose extract. The length of the juice stroke for skins weighing from 20 to 25 kg-20 tanks, for weights from 25 / v2 and above-28 tanks, and for weights below 20 lg, the stroke length is up to 18 tanks.

In the case of chipping, the length of the juice course for cheprakov is up to 28 vats and for descents up to 14 vats.

The density of the head vats of the juice passages is determined by the liquid coefficient and the calculation of the number of tannids in the juice course.

The temperature of the head vat is 32 ° (in winter, three vats are heated from the head tank). The temperature of the remaining vats is natural, the pH of the head vat is 4, and the rest is normal. Liquid Coefficient b. The tail and head tank are drained once every two days. The transfer of leather from the vat to the vat is daily. After dyeing, the water in the juice course (preferably fully) the semi-finished product is fed to the drum doubled, with oak extract at a density for light skins and gatherings within 8 ° Be and for heavy skins and ceprac-10 Be.

The temperature of the pouring juice is 32 °, pH-4, the temperature at the end of tanning is not higher than 38 °, the liquid coefficient is from 2 to 3 (by calculation). Duration of tanning in a drum for cheprakov and heavy leathers up to 72 hours with two or three reinforcements, and for light leathers

and gatherings, from 36 to 48 hours with two supports.

In order to prevent the juices from aging, periodically, as a rule, after 30 days, the juice is completely refreshed (drained) in the drum (juice refreshment is not performed if the full drum is drained).

After complete blowing, the semi-finished product is allowed to lie in a sheltered state, in summer not more than 24 hours and in winter not more than -18 hours. Then the semi-finished product is supplied for deoxidation, for cheprak and heavy leather-by weight (3-vat system) for a time of 36 hours with a transfer from the vat every 12 hours.

A strong wash juice with a density of 1-1.5 We has been used in the preparation of the juice of the head tub, and can also be given instead of water when the extracts are boiled.

Light skin and gatherings, after daily washing in a tank by weight or

in the spread, washed in a drum with a liquid coefficient of 5 for 1-1.5 hours. The water temperature in all cases of washing operations is not lower than 25.

After washing the skin is pressed on the hydraulic press under a pressure of up to 250 atm. and pass on the fat.

The subject matter of the invention.

The method of tanning gol by the combined method, first with juice stroke, then in drums and using, along with oak extract, sulphite-cellulose extract, characterized in that sulphite-cellulose extract is used exclusively in juice course and in the amount of about one third of oak extract , counting on soluble tannids, sticking to the head vat of the juice course the concentration of pH ions is about four.