The invention provides a low-temperature enzyme unhairing method for preparing cow leather. The method comprises the following steps: (1) cleaning: cleaning fresh cow leather, removing the dirts attached on the surface of the leather and needless subcutaneous tissues; (2) performing enzyme unhairing: adding a conventional enzyme for unhairing in water at 15-28 DEG C, adjusting the pH value to 7.5-11 to unhair; (3) unhairing: removing the loose hairs on the leather; performing alkali steeping and dealkalization: steeping the leather in a sodium hydroxide solution, introducing CO2 gas at the room temperature to dealkalize and ensure that the the pH value at the end point is 7.5-8.5; and (5) tanning to obtain the finished cow leather. The prepared leather hardly contains sulfide residues.

Cow leather without sulfide residues and low-temperature enzyme unhairing preparation process thereof

The invention discloses a tanning method free of lime, sulfide, chloride ion and heavy metal chromium pollution. The tanning method is characterized in that the pollution of lime, sulfide, chloride ion and heavy metal chromium is not generated in the whole pre-tanning preparation and tanning process, so that main pollutants for tanning are completely eliminated. The processes include a soaking pre-treatment process, a composite enzyme depilation process and a chromium-free tanning process which are combined in an optimized manner and cooperated to develop a novel clean tanning method, so that the prepared finished leather satisfies the national standards, and a lime, sulfide, chloride ion and heavy metal chromium pollution problem which troubles the tanning industry all the time is radically solved, and therefore, the environment is protected and the waste is turned into things of value. Moreover, the tanning method further can be used for greatly lowering the material cost and increasing the economic benefits.

Tanning method free of lime, sulfide, chloride ion and heavy metal chromium pollution

The invention relates to the treatment field of animal furs and particularly relates to a method of preparing sheepskin clothing face garment leather with a small liquor ratio The method comprises the following steps: pre-treating soil-species sheepskin in a paddle-tumbler, wherein the pretreatment includes the steps of soaking in water, washing the skin, re-soaking in water, shearing, removing meat and degassing, and a weight ratio of the water to the raw material kin in each pretreatment step is 9-11; then, performing pickling, depickling, re-pickling, tanning, re-tanning, neutralizing and oiling in a rotary drum in sequence, wherein a weight ratio of the water to the raw material skin in each treatment step is 5-7; and performing the processes of drying, moisture regaining, staking, dry cleaning, fine pruning, scalding, dry grinding and clearing to obtain the sheepskin clothing face garment leather According to the method disclosed by the invention, the soil-species sheepskin is prepared into the sheepskin clothing face garment leather by adopting a small liquid ratio in the paddle-tumbler and the rotary drum, so that the water consumption in the process is reduced, the chemical materials are reduced correspondingly; and the finally prepared sheepskin clothing face garment leather is white in fur color, fine in dermatotome, full, soft and elastic in hand feeling and high in quality

Method of preparing sheepskin clothing face garment leather with small liquor ratio

The invention relates to a tanning production technology. The tanning production technology includes the following sequential steps of soaking, fleshing, depilating, hair shoveling, alkali expanding, splitting, dealkalizing, softening, pickling and tanning; then production is conducted according to a conventional chrome tanning follow-up technology; in the preparing process, a novel ash-free and sulfur-free technology is adopted, generation of sulfides is avoided, sludge generated when lime powder is used is avoided, and the sludge discharging problem of an enterprise is solved; and an ammonia-free dealkalizing and subsalt technology is adopted in the tanning process, so that ammonia nitrogen discharging and industrial salt discharging pollution is greatly reduced. By means of the novel sulfur-free, ash-free, ammonia-free and subsalt technology, produced leather is soft in hand feel and good in fullness, all indexes of the produced leather reach EU standards, and the produced leather is exported to Europe and receives consistent praise from users.

Tanning production technology

The invention relate to the technical field of animal fur manufacturing, in particular to a production method for buffalo hide shoe upper leather. Specifically, carboxymethylcellulose sodium, borax, diethylene glycol and water are mixed to obtain depilation liquid, the depilation liquid is sprayed on buffalo hide hair roots, after freezing normal temperature treatment, buffalo hair is removed, surface hair is rinsed thoroughly, depilated buffalo hide is immersed in water, expansion is realized by using ultrasonic treatment, endopeptidase, exopeptidase, tannase and acid pectinase are mixed and configured to obtain a complex enzyme preparation, the complex enzyme preparation is mixed with aqueous urea solutions to serve as softening fluid, the buffalo hide after expansion treatment is immersed in the softening fluid for softening, and finally leather buffing is carried out.

Production method for buffalo hide shoe upper leather

The no-ash and no-sodium sulfide liming process for making pigskin leather features its greatly reduced pollution, and no use of pollutant sodium sulfide, sodium hydrosulfide and lime makes it easy to treat exhausted waste water. Compared with conventional technological process, the present invention has the advantages of no deposit, reduced waste water exhaust, short production period, saving in material and lowered comprehensive cost.

Zhihua Shan

Papers

Method for ash-free and no-sulfurizing alkaline liming treatment for making pigskin leather