The method of processing of raw hides

 

(57) Abstract:

The method relates to the processing of raw hides and can be used in the production of leather from the hides of cattle and sheep, for example, for the uppers, clothing and fancy goods. The skins are washed and subjected to: soaking off. Then make processing of hides and skins with an aqueous solution of potassium permanganate and sodium carbonate at pH 6-9 with the concentration of potassium permanganate 0,02-0,05 g/l for 1 h at 28-36oAnd liquid ratio of 1. After which the skins obespechivajut in an aqueous solution of enzyme preparation for 2.5-3.5 h at 28-36oWith subsequent liming in an aqueous solution of sodium sulfide and calcium hydroxide.

The invention relates to light industry and can be used in the production of leather from the hides of cattle and sheep (for the uppers, clothing, fancy goods, and others).

Closest to the claimed method is a method of processing leather raw material for the patent of the Russian Federation 2117048, including leaching,: soaking off, the dehairing of hides and skins in an aqueous solution of enzyme preparation, liming in an aqueous solution of sodium sulfide and calcium hydroxide. As the enzyme preparation used integrated the e impact on raw hides, in particular at the stage of dehairing and other stages of processing. The dehairing by this method spend 30-39oFor 6-20 h and liming in the interval 20-30oFor 6-15 hours

Another problem in the processing of raw hides is the problem of removal of podsada - young hair, which is not always completely removed after enzymatic dehairing. Posed remains on the skin and it reduces the quality of the final product and reduces the output area of finished leather.

In the prototype removal podsada is achieved in the subsequent obessolivaniju process - liming by treating the skin with a solution of sodium sulfide and calcium hydroxide. Remove podsada more effective at increasing the concentration of sodium sulfide. However, this increases the cost of wastewater treatment. The increase in the length of the ashing process at a normal concentration of sodium sulfide does not always lead to the complete destruction of podsada.

The technical challenge is to improve the process for dehairing hides through more efficient removal of podsada and reduction in the duration of dehairing.

This technical result is achieved by creation enzyme preparation, the liming in an aqueous solution of sodium sulfide and calcium hydroxide, in accordance with the invention after soaking before obezbolevaniem raw materials to produce a treatment with an aqueous solution of potassium permanganate and sodium carbonate with a concentration of permanganate of potassium, a component of 0.02-0.05 g/l, pH 6-9 at 28-36oC for 1 h with the value liquid ratio of 1. The dehairing carried out in an aqueous solution of enzyme preparation "Good" with a concentration of 0.2 to 0.8% by weight of the raw material and pH 6-8, at 28-36oWith for 2.5-3.5 hours with liquid ratio of 0.8-1.0. The liming is conducted with an aqueous solution of sodium sulfide and calcium hydroxide with a concentration of 0.2-1.0, and 1.5 to 2.5% by weight of raw materials at 18-26oWith over 5-13 h with liquid ratio of 0.7 to 1.9.

When processing the skins of the present invention potassium permanganate and sodium carbonate posed remaining on the skin after carrying out enzymatic dehairing, remove liming.

The method in accordance with the invention is as follows. The skins are washed and subjected to: soaking off at 20-22oC, then treated with an aqueous solution of potassium permanganate for 1 h at 28-36oWhen the pH value of 6-9. Optimal is amperage amount of sodium carbonate. The concentration of potassium permanganate in solution is 0.02-0.05 g/l, optimally 0.035 g/l Processing produce when set to liquid ratio of 1. Then make the dehairing of skins when liquid ratio of 0.8-1.0 in a solution of enzyme preparation "Good" at a rate of 0.2 to 0.8% by weight of the raw material at pH 6-8 for 2.5-3.5 h at 28-36oC.

After the enzymatic treatment the skins carry out liming when liquid ratio of 0.7 to 1.9 in an aqueous solution of sodium sulfide and calcium hydroxide with a concentration of sodium sulfide, 0.2 to 1.0% of calcium hydroxide and 1.5-2.5% by weight of raw materials at 18-26oWith over 5-13 hours resulting from the implementation of the above method, the skins may not be abating and cleaning "person" in subsequent treatments.

Quality finished leather, obtained by carrying out the invention meets the requirements of state Standards of the Russian Federation on leather for Shoe upper, lining and haberdashery leather.

Below are examples of the method of processing of raw hides in accordance with the present invention and for comparison, the method described in the patent of the Russian Federation 2117048.

It should be noted that in all examples of the operation for washing and: soaking off the skins /P> EXAMPLE 1.

In accordance with the present invention washed and otoczenie skins treated with an aqueous potassium permanganate solution with a concentration of 0.02 g/l for 1 h at 36oC and pH 6.6, liquid ratio was equal to 1. Then hold the dehairing, in which the skin is treated with an aqueous solution of enzyme preparation "Good" with a concentration of 0.3% by weight of the skins for 3 h at 34oC and pH 6.5, at a volume ratio of 1. Then obezbashennye skins are subjected to liming aqueous solution of sodium sulfide and calcium hydroxide with a concentration of, respectively, 0.3 and 1.8% by weight of the skins for 6 h at 22oWith volume ratio 1. The area of skin with podsada after dehairing amounted to 3% of the entire area of skin. Posed was removed in the subsequent ashing for 5 minutes Further processes and operations performed by a typical method for the manufacture of finished leather. Obtained according to Example 1 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 29%; tensile strength tensile - to 25.3 MPa, the stress at the crack front layer compared to 24.2 MPa. Hydrothermal stability of finished leather was 111oC.

EXAMPLE 2.

oWith a pH of 8.4, liquid ratio was equal to 1. Then hold the dehairing, in which the skins are treated with an aqueous solution of enzyme preparation "Good" with a concentration of 0.6% by weight of the skins for 3.5 h at 29oC, at pH 7.5, with volume ratio 1. Then obezbashennye skins are subjected to liming aqueous solution of sodium sulfide and calcium hydroxide with a concentration of, respectively, 0.3 and 2.0% by weight of the skins for 6 h at 22oWith volume ratio 1. The area of skin with podsada after dehairing amounted to 3% of the entire area of skin. Posed was removed in the subsequent ashing for 5 minutes Further processes and operations performed by a typical method for the manufacture of finished leather. Obtained according to Example 2 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 28,5%; tensile strength tensile and 25.8 MPa stress at the crack front layer of 24.7 MPa. Hydrothermal stability of finished leather was 112oC.

EXAMPLE 3.

Washed and otoczenie skins treated with an aqueous potassium permanganate solution with a concentration of 0.035 g/l for 1 h at 34oC, at pH 7.5, the liquid ratio was equal to 1. D. the concentration of 0.5% by weight of the skins for 3 h at 34oC, at pH 7.5, with volume ratio 1. Then obezbashennye skins are subjected to liming aqueous solution of sodium sulfide and calcium hydroxide with a concentration of, respectively, 0.3 and 1.8% by weight of the skins for 6 h at 22oWith volume ratio 1. The area of skin with podsada after dehairing amounted to 0% of the entire area of skin. Subsequent treatment is carried out under the typical method of manufacture except for bating. Obtained according to Example 3 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 31%; tensile strength tensile - 26,4 MPa stress at the crack front layer is 25.2 MPa. Hydrothermal stability of finished leather was 114oC.

EXAMPLE 4.

All operations were carried out as described in example 3, but the dehairing carried out for 2.5 h, the subsequent tanning of leather is done according to standard methods. Obtained according to Example 4 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 31%; tensile strength tensile - 26,3 MPa stress at the crack front layer of 25.1 MPa. Hydrothermal stability of finished leather was 113,5oC.

EXAMPLE 5.

Washed out and about the oC, at pH 6.5, the liquid ratio was equal to 1. Then hold the dehairing, in which the skin is treated with an aqueous solution of enzyme preparation "Good" with a concentration of 0.3% by weight of the skins for 3.5 h at 28oC, at pH 7.5, with volume ratio 1. Then obezbashennye skins are subjected to liming aqueous solution of sodium sulfide and calcium hydroxide with a concentration of respectively 0.5 and 2.0 percent by weight of the skins for 7 h at 22oWith volume ratio 1. The area of skin with podsada after dehairing amounted to 5% of the entire area of skin. Posed was removed in the subsequent ashing for 5 minutes Further processes and operations performed by a typical method for the manufacture of finished leather. Obtained according to Example 5 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 28%; tensile strength tensile - 23,9 MPa stress at the crack front layer and 23.1 MPa. Hydrothermal stability of finished leather was 109oC.

EXAMPLE 6.

In accordance with the processing method described in the patent of the Russian Federation 2117048, washed and otoczenie skins treated with an aqueous solution of enzyme preparation "Good" with a concentration of 0.3% from mA subjected to liming aqueous solution of sodium sulfide and calcium hydroxide with a concentration of 0.6 and 2.2% by weight of the skins for 8 h at 25oWith volume ratio 1. The area of skin with podsada after dehairing amounted to 8% of the entire area of skin. The resulting posed in the implementation of the next 15-hour ashing at 30oWith not completely removed. Further, the processes and operations performed by a typical method for the manufacture of finished leather. Obtained according to Example 6 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 25%; the limit tensile stress is 22.2 MPa stress at the crack front layer is 21.4 MPa. Hydrothermal stability of finished leather was 104oC.

EXAMPLE 7.

All operations are performed as described in example 6. To remove podsada spend liming when the concentration of sodium sulfide to 1.5% by weight of the raw material, which is beyond the scope specified in the patent, the concentration of calcium hydroxide is the same as in Example 6, and a temperature of 25oC. Posed was removed completely for 3 h at carrying out ashing for 6 Further including the processes and operations performed by a typical method for the manufacture of finished leather. Obtained according to Example 7 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 25%; the limit tensile stress is 22.2 MPa; voltage when ptx2">

EXAMPLE 8.

In accordance with the patent of the Russian Federation 2117048 washed and otoczenie skins treated with an aqueous solution of enzyme preparation "Good" with a concentration of 0.5% by weight of the skins for 11 h at 35oC, at pH 7.5 when liquid ratio of 1. Then obezbashennye skins are subjected to liming aqueous solution of sodium sulfide and calcium hydroxide with a concentration of respectively 0.5 and 2.0 percent by weight of the skins for 8 h at 22oWith volume ratio 1. The area of skin with podsada after dehairing amounted to 4% of the entire area of skin. The resulting after the dehairing posed managed to completely remove when performing subsequent ashing with increasing duration ashing up to 12 hours and the temperature is raised to 28oC. Further, the processes and operations performed by a typical method for the manufacture of finished leather. Obtained according to Example 8 of the skin characterized by the following properties: elongation at tension of 9.8 MPa - 29%; the limit tensile stress is 25.2 MPa stress at the crack front layer 24,0 MPa. Hydrothermal stability of finished leather was 110oC.

Thanks disbacteriosis and anti-corrosion properties of potassium permanganate using econstructed used to implement the process equipment.

The method of processing of raw hides, including its flushing,: soaking off, the dehairing of hides and skins in an aqueous solution of enzyme preparation, liming in an aqueous solution of sodium sulfide and calcium hydroxide, characterized in that after soaking before obezbolevaniem make processing of skins with an aqueous solution of potassium permanganate and sodium carbonate at pH 6-9 with the concentration of potassium permanganate 0,02-0,05 g/l for 1 h at a temperature of 28-36C and volume ratio equal to 1, while the dehairing carried out for 2.5-3.5 hours in a 28-36C.

 

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FIELD: fur industry.

SUBSTANCE: fur fells are treated with aqueous solution of nonionic surfactant and antiseptic, which is aqueous dispersion of acrylic copolymer with dimethylformamide at ratio (1.0-1.1):(5.0-5.1), respectively.

EFFECT: improved physico-mechanical characteristics of fur fells and improved environmental condition.

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