Method for combined tanning leather

FIELD: leather industry.

SUBSTANCE: method involves pickling leather depilated hide with sodium chloride and sulfuric acid, addition of chrome tanning agent to the same bath in its consumption 0.5-0.6% of depilated hide mass as measured for chrome oxide, and chrome-plating is carried out for 2-4 h. Aliphatic dialdehyde is added to same bath in the concentration 3-6% of depilated hide mass, and treatment is carried out for 2-3 h wherein glyoxal or glutaraldehyde is used as dialdehyde. Invention provides enhancing thermal stability and strength properties of leather and can be used in tanning leathers for different designation and assortment.

EFFECT: improved tanning method.

2 cl, 1 tbl, 9 ex

 

The invention relates to the leather industry and can be used for tanning leather for various purposes and range.

The known method combined tanning leather, including processing marcenaro of the hide at 60-70°With formaldehyde and resorcinol at a rate of 0.5 mole of formaldehyde to 1 mol of resorcinol at a flow rate of the last 0.5 to 5% by weight of the hide, chrome plating for 30-40 min chrome-extract 15-35%of basicity in the amount of 0.5-0.7% in terms of oxide of chromium and chrome tanning extract 15-35%of basicity in the amount of from 1.0 to 1.75% by weight of the hide, in terms of oxide of chromium for 4-6 hours at a temperature of 22-35°With (SU 174753, SS 3/08, 07.09.1965).

The disadvantage of this method is that the joint processing of the hide formaldehyde and resorcinol at 60-70°promotes intense binding of the aldehyde in the surface layers of the dermis, resulting in zdublowany skin and deterioration of their quality.

The closest analogue of the proposed technical solution is the way combined tanning leather, including pickling pickling, processing hydroxybutylidene in the amount of 2.5-3.0% by weight of the hide for 3-4 h and processing of chrome tanning agent for 9-10 h (EP 0822263 B1, SS 1/08, 13.10.1999).

The disadvantage of this method is that the treatment of hydroxybutylidene the house before chrome tanning chrome does not allow the tanning agent fuller and deeper understanding of the structure of the dermis, which makes it impossible to get ready skin with high strength properties and heat resistance, and reduce the pollution of waste water by chromium compounds.

The technical result of the proposed technical solution is to improve the quality of skin by increasing their heat resistance and strength properties, as well as reduction of pollution of wastewater compounds of chromium.

This result is achieved in that in the method of the combination tanning of skins, including pickling pickling, processing aldehyde and chrome plating, processing aldehyde produced in the waste after plating bath, the plating is carried out for 2-4 hours at a flow rate of chrome tanning agent 0.5 to 0.6% by weight of the hide, in terms of oxide of chromium, as the aldehyde used aliphatic dialdehyde in the amount of 3-6% by weight of the hide and processing them are within 2-3 hours And as aliphatic dialdehyde using glyoxal or glutaric aldehyde.

A distinctive feature of the proposed method is that the treatment of aliphatic dialdehyde after chrome plating allows for maximum binding of chromium compounds with collagen of the dermis due to the formation of larger fromaldehyde complexes, which significantly increases thermal stability and mechanical properties of the skin, also leads to almost complete chrome tanning agent from the treatment solution.

Conducting plating and processing the dialdehyde at a cost of chrome tanning agent is less than 0.5% and dialdehyde less than 3% by weight of the hide less than 2 hours each not allow you to get ready skin with high strength properties and heat resistance. Carrying out plating at a flow rate of chrome tanning agent than 0.6% by weight of the hide, reduces viviremos tanning material from the treatment solution. The treatment of the dialdehyde in the amount of more than 6% by weight of the hide, increases the stiffness of the leather. Conducting processes of chrome and processing the dialdehyde over 4 and 3 h, respectively impractical, so as to further improve the quality of the leather does not occur.

The method is as follows.

The hide, obtained from the skins of cattle by known techniques, is subjected to pickling in accordance with the standard method, and then produce plating at a flow rate of chrome tanning agent 0.5 to 0.6% by weight of the hide, in terms of oxide of chromium within 2-4 hours Then in the same tub impose glyoxal or glutaric aldehyde in the amount of 3-6% by weight of the hide and processing is done within 2-3 hours Further processes and operations carried out by known technologies depending on the destination of the skin.

Example 1. The hide, obtained from the skins of cattle by known techniques, is subjected to pickling sodium chloride and sulphuric acid in them is ashade respectively 6 and 1% by weight of the hide with LCD 0.7 and a temperature of 20-22°C. Then, in the same tub impose chrome tanning agent in an amount of 0.6% by weight of the hide, in terms of oxide of chromium. The process of chrome plating is carried out for 4 hours After that in the same bath add glyoxal in the amount of 6% by weight of the hide, and the treatment continued for 3 hours Further processes and operations carried out by the method of production of chrome-tanned leather for Shoe uppers.

Example 2. The hide, obtained from the skins of cattle by known techniques, is treated as in example 1, but the plating is carried out at the expense of chrome tanning agent to 0.55% by weight of the hide, in terms of oxide of chromium for 3 h, and processing glyoxal are at a flow rate of 4.5% by weight of the hide for 2.5 hours Further processes and operations carried out by the method of production of haberdashery leathers.

Example 3. The hide, obtained from the skins of cattle by known techniques, is treated as in example 1, but the plating is carried out at the expense of chrome tanning agent is 0.5% by weight of the hide, in terms of oxide of chromium for 2 h, and processing glyoxal lead at the rate of 3% by weight of the hide for 2 hours Further processes and operations carried out by the method of production of leather for clothing.

Example 4. The hide, obtained from the skins of cattle by known techniques, is treated as in example 1, but the plating is carried out at the expense of chrome tanning agent 0.4% by weight goal is I in terms of chromium oxide over 4.5 h, and the processing glyoxal is carried out at a rate of 2.5% by weight of the hide within 3.5 hours Further processes and operations carried out by the method of production of leather for clothing.

Example 5. The hide, obtained from the skins of cattle by known techniques, is treated as in example 1, but the plating is carried out at the expense of chrome tanning agent to 0.7% by weight of the hide, in terms of chromium oxide for 1.5 h, and processing glyoxal are at a flow rate of 6.5% by weight of the hide for 1.5 hours Further processes and operations carried out by the method of production of chrome-tanned leather for Shoe uppers.

Example 6. The hide, obtained from the skins of cattle by known techniques, is subjected to pickling sodium chloride and sulfuric acid at their expense, respectively, 6 and 1% by weight of the hide with LCD 0.7 and a temperature of 20-22°C. Then, in the same tub impose chrome tanning agent in an amount of 0.6% by weight of the hide, in terms of oxide of chromium. The process of chrome plating is carried out for 4 hours After that in the same bath add glutaric aldehyde in the amount of 6% by weight of the hide, and the treatment continued for 3 hours Further processes and operations carried out by the method of production of chrome-tanned leather for Shoe uppers.

Example 7. The hide, obtained from the skins of cattle by known techniques, is treated as in example 6, but the plating is carried out at the expense of chrome tanning agent to 0.55% by weight of the hide in PE is eschete on the chromium oxide for 3 h, and the treatment with glutaraldehyde are at a flow rate of 4.5% by weight of the hide for 2.5 hours Further processes and operations carried out by the method of production of haberdashery leathers.

Example 8. The hide, obtained from the skins of cattle by known techniques, is treated as in example 6, but the plating is carried out at the expense of chrome tanning agent is 0.5% by weight of the hide, in terms of oxide of chromium for 2 h, and the treatment with glutaraldehyde lead at the rate of 3% by weight of the hide for 2 hours Further processes and operations carried out by the method of production of leather for clothing.

Example 9. The hide, obtained from the skins of cattle by known techniques, is treated as in example 6, but the plating is carried out at the expense of chrome tanning agent 0.4% by weight of the hide, in terms of oxide of chromium for 4.5 h, and the treatment with glutaraldehyde is carried out at a rate of 2.5% by weight of the hide within 3.5 hours Further processes and operations carried out by the method of production of leather for clothing.

Example 10. The hide, obtained from the skins of cattle by known techniques, is treated as in example 6, but the plating is carried out at the expense of chrome tanning agent to 0.7% by weight of the hide, in terms of chromium oxide for 1.5 h, and the treatment with glutaraldehyde are at a flow rate of 6.5% by weight of the hide for 1.5 hours Further processes and operations carried out by the method of production is TBA chrome-tanned leather for Shoe uppers.

Qualitative indicators of finished leather in comparison with the skin of the prototype presented in the table.

The use of the proposed method will allow you to get ready skin with high performance properties and to reduce wastewater pollution tanneries chromium compounds.

Table
IndicatorsExamplesPrototype (leather for the uppers)
12345678910
The ultimate tensile strength of 10 MPa1,801,351,201,001,601,751,251,151,151,651,40
The stress at the crack front layer 10 MPa1,75---1,451,70---1,551,20
The elongation stress of 10 MPa, %3830554820352860 352525
Temperature welding, °9895928998989394859885
Mass fraction of chromium oxide in the skin, %2,01,81,61,52,02,01,81,61,52,01.6
The content of Cr2About3in the waste liquid after tanning, g/l0,30,20,10,20,50,30,20,10,20,52,5

1. The method combined the leather tanning, including pickling pickling, processing aldehyde and chrome plating, characterized in that the processing of the aldehyde produced in the waste after plating bath, the plating is carried out for 2-4 hours at a flow rate of chrome tanning agent 0.5 to 0.6% by weight of the hide, in terms of oxide of chromium, as the aldehyde used aliphatic dialdehyde in the amount of 3-6% by weight of the hide and processing them are within 2-3 hours

2. The method according to claim 1, characterized in that aliphatic dialdehyde use gloox the eh or glutaric aldehyde.



 

Same patents:

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FIELD: leather industry.

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EFFECT: enhanced quality of tanning.

2 tbl

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FIELD: leather and fur industry.

SUBSTANCE: method envisages culturing of kefir fungal or kurungal ferment (obtained in amount 50%) on a nutrient medium, which medium is pasteurized skim milk for four first culturing days, pasteurized mixture composed of skim milk and fat-free curds whey on 6-14th days, and pasteurized fat-free curds whey on 15-18th days. Culturing is carried out for 18 days at 22±1°C and mechanical shaking twice a day for 15 min to give ferment with acidity 350-360°T. Ferment may be added to pasteurized cooled milk or to pasteurized curds whey in amounts 25% followed by fermentation at 22±1°C and acidity 350-360°T.

EFFECT: increased stability of ferment (double storage time), its acid-generating capability, and population autoregulation, increased activity to accumulate lactic acid by 2 1/2 times, and reduced restoration time by 4-6 h.

2 cl, 4 tbl, 6 ex

FIELD: fur industry.

SUBSTANCE: invention is directed to processing fur sheepskin intended for manufacturing clothing, headgears, footwear parts and other fur items. Crude fur sheepskin of all preservation types is subjected to soaking, first degreasing, squeezing, haircutting, and fleshing according to known technology. Then fur sheepskin is subjected to additional processing in aqueous solution of sodium chloride (15-20 g/L) and nonionic surfactant composition (1-2 g.L) for 2-6 h at 30-32°C. After second degreasing and washing, pickle salting is carried out for 20-24 h. 4-6 hours after the beginning of pickle salting, processing solution is supplemented by 3-5 g composition of nonionic surfactants (1:1 mixture of Neonol AF 9-12 and syntamide 5). Finally tanning and greasing are performed.

EFFECT: improved performance characteristics fur sheepskin intermediate product.

2 cl, 1 tbl, 5 ex

FIELD: fur industry, in particular, process for pickling of sheepskin fur coats and raw fur material.

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EFFECT: improved quality of fur sheepskins due to reduced curling of hair-covering and improved elastoplastic properties thereof.

4 tbl, 4 ex

FIELD: defatting of crude sheepskin-and-fur material.

SUBSTANCE: method involves treating crude material in bacterial suspension having lipolytic activity of 20-30 units/g and proteolytic activity of 2.5-3.5 units/g. Suspension contains product of total microorganism vital activity used in an amount of 4-8 g/dm3, synthetic surfactant used in an amount of 0.25-0.5 g/dm3, and prokaryotic crop of Pseudomonas sp. type used in an amount of 107-109 cells/cm3, water the balance. Treatment is conducted at temperature of 40±2 C during 45 min by providing mechanical actions, and liquid coefficient of 7-10.

EFFECT: improved quality of defatting sheepskins, improved elastoplastic properties and reduced level of toxic contamination of sewage water.

3 dwg, 4 tbl

FIELD: leather industry.

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2 tbl

FIELD: fur industry, in particular, method for evaluating pickling quality of leather web in tanning of fur and sheepskin raw material.

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1 tbl, 1 ex

FIELD: fur industry, in particular, method for evaluating pickling quality of leather web in tanning of fur and sheepskin raw material.

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EFFECT: reduced time for determining quantitative pickling characteristic of skin web.

2 tbl, 2 ex

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