SU546652A1 - Method for the production of leather for the top of shoes from pork skins - Google Patents

Description

one

The invention relates to leather production technology, in particular to the chemical treatment of leather before tanning, and can be used in tanneries for processing pork skins.

A known method for the production of leather for shoes from animal skins, including dehairing by treating them with a solution of sodium sulphide at a concentration of NasS of 3-10 g / l and a pH value of 8-12, neutralized with acid SALTS of alkali metals, followed by lime lime ash.

The known method does not find application in the processing of pork skins due to the peculiarities of their histological structure.

A known method for the production of leather for the top of shoes from pork raw materials of the type DOL in a smooth form, is that the doubling of hides is done in the hem, the usual modes of i9delivery (temperature, LCD, duration, etc.) are used for prognosis, predubilny, tannic and dye - fatty processes, the facial layer is removed on a folding machine in a semifinished product, the finishing operations are carried out in such a way that the natural measure of pigskins is preserved in the finished skin, and, consequently, in the shoes.

The skins produced by this technology are characterized by uneven density in topographic areas, the looseness of the peripheral areas, the presence of holes from the bristles, the absence of a collective neck due to the multi-layer application of coating paint and fixing with nitro-enamels.

In order to improve the quality of skins extracted from pigskins, ghosting followed by removal of the face layer is carried out after

Remove the bristles from the skin before ashing.

Moreover, the doubling is carried out on the thickness

2.9-3.2 mm, and the removal of the facial layer on

0.1-0.2 mm.

Surface-active substances (surfactants) are used to accelerate wet-dip, pre-tanning and tanning operations, this contributes to the intensification of all these processes, which leads to the maximum loosening of the skin fibrous structure,

consequently, getting soft skin. In addition, the intensification of processes contributes to the reduction of the duration of the production cycle. Removing the facial layer after pulling out the bristles creates conditions for a continuous production line in finishing operations.

An example of the use of the proposed method for the production of chrome leather for the upper shoe of high quality from pork raw materials

DOL-PC is as follows.

First, the usual washing according to the method for screw apparatus is performed, then the washing is performed by degreasing using surface-active substances (surfactants), the liquid coefficient of the liquid is 2.0-2.5, the temperature is 36-38 °, the duration is 13-15 hours, s using:

NaaCOs16-18 g / l

NaaSOs5 g / l

NaaS0,4-0,5 g / l

PAV 0.5 g / l

and pulling out the bristles.

Sawing into raw materials is carried out in two stages: the first doubling is the thickness of the upper split 2.9-3.2; Doubling the second - the thickness of the front split 0.4-0.2, the main - 2.7 - 3.0 mm.

After sawing up in raw materials - short saling and dosage of chemicals according to the method.

The length of time for raw materials weighing up to 4 kg is 8-16 hours, for heavier weights up to 24 hours.

The pre-tanning and tanning processes are carried out in the usual manner, but when softened, the surfactant is added in an amount of 0.5% of the blue weight.

In dyeing and fatty processes and filling, surfactants in the amount of 0.4% are also used, and for filling, synan No.2 in the amount of 5% is used, considering that the skin that weighs the weight of the leather after cutting from the raw material is 4 kg; 2.5% willow extract and

Comparable process acceleration data

According to the methodology approved by the USSR MLP

Duration of ash hours. Duration gchenn 1.5-3.0 hours

The duration of tanning processes 12-16 hours

The name of the semi-finished product after tanning

Pig leather chromium, experienced Pig leather chromium, variety

2.5% of ATP syntan, counting as dubbing, for skins from raw materials of small weights.

Synthetic organic tanning agents are used to fill and seal loose peripheral skin areas.

Drying, laying, moisturizing, skinning are carried out according to the usual technology.

When first grinding the front surface of the code and cleaning from dust there is no removal

upper facial layer of skin, which is held in raw materials. Then non-pigmented impregnating primer is applied at a rate of 220-250 g per 1 sq. M. m, while using impregnating and colorless soils to mask the natural measure of pig cheekbones.

After that, the skin is laid at 20-22 ° C for at least 8 hours and not more than 24 hours, their suspension and pulling are done, and the skin is pressed with a dust-like slab to give a natural

measure skin.

Then a second grinding of the skins and dusting is performed, colorless primer is applied once, then pigmented primer, the skin is pressed with a dust-like slab, the second

pigmented soil is applied once, a higher viscosity topcoat is applied, a smooth slab is pressed on the skin, a topcoat is applied a second time and fixed with nitroemulsion lacquers to give the skin a natural exterior and maintain a leather-like neck.

Table 1

According to this invention

The duration of ashing is 8-16 hours, for heavy weights 24 hours.

Duration of softening in the presence of surfactant 1.0-2.0 h.

The duration of tanning processes in the presence of surfactant 3-4 hours

table 2

Data analyzes fat content,%

1.0 4.5

Table 3 5 Comparative table of data of experienced 546652 B Table 4 and control leathers according to factory laboratory data

The data show that there is a tendency to a greater absorption of chromium oxide in the experienced skin as compared to coprool, as well as to a decrease in the fat content and an increase in the rupture of the facial layer.

This invention allows to fully mechanize, intensify the process and get the skin of good appearance - skin type from cattle hides, dense to the touch, uniform throughout all topographic areas (floors of rollers) with the elimination of perfume and salinity. The leather obtained using the proposed method completely imitates chromic leather from cattle hides, both externally and qualitatively.

Claims (2)

1. A method of producing leather for the upper of a shoe made from pork skins, containing a squeeze followed by removing the bristles from the skins, salting, doubling, tanning and removing the face layer, characterized in that, in order to improve the quality, doubling followed by the removal of the face layer carried out after removing the bristles from the skin before debasing. 2. A method according to claim 1, characterized in that the doubling is carried out by a thickness of 2.9-3.2 mm, and the removal of the face layer by 0.1-0.2 mm.