CS256505B1 - Method of animal skins' degreasing and cleaning - Google Patents

Abstract

The method solves degreasing and cleaning animal's fur without unwanted hardening the leather belt that the ee performs by processing skin in organic solvent, then ee usually performs centrifugation and drying leather. The method is characterized in that the skins are degreased by washing in organic a dihalormethane based solvent at at 10 to 41 ° C, for 3 to 15 mi-n then dried at 20 to 50 ° C. The most preferred skins are degreased under atmospheric conditions air. It uses the solution physically chemical properties of diohlormethane, which does not require reduced working pressure prooeeu and has a higher degreasing and cleaning than the organic solvents used so far. For application of diohlormethane for degreasing and cleaning the skins can be used the usual devices used by ee for prior art fluorocarbon processes or chlorinated hydrocarbons.

Description

Vynáles solves the method of degreasing and cleaning of animal skins without undesirable hardening of the skin belt, which is carried out by processing the skins in an organic solvent, followed by the usual skimming and drying of skins ·

The earliest ways of removing fat and dirt from animal skins were based on the imperfect and unproductive processing of greasy and impure skins in dry beech sawdust. · Later it came to degreasing and cleaning skins in organic solvents. · Perchlorethylene or triethlorethylene cannot be used as the leather belt hardens during subsequent drying, which prevents further technological processing of animal skins.

However, degreasing and cleaning of animal skins in fluorocarbons has a number of disadvantages. · For degreasing and cleaning in fluorocarbons, special machines must be used, which are very complex and have a small working space. · The maximum load is 22 kg. Larger working volumes cannot achieve the economically viable vacuum required to run the process under reduced pressure · This is due to the high cost of fluorocarbons · Also, the working process cannot be interrupted for sampling because of the loss of vacuum ·

- 2 Leaking of fluorocarbons into the atmosphere my very damaging ecological consequences *

Most of these deficiencies are eliminated by a method of degreasing and cleaning animal skins without unwanted hardening of the skin belt, which is carried out by treating the skins in an organic solvent, followed by conventional skimming and drying of the skins. at a temperature of 10 to 41 ° C for 3 to 15 minutes, after which the skins are dried at a temperature of 20 to 50 ° C. The present invention utilizes the physicochemical properties of dichloromethane, which does not require reduced working space pressure and has a higher degreasing and cleaning effect than the organic solvents used hitherto. Degreasing effect and increases by approximately 15% · To apply dichloromethane for degreasing and skin cleaning and using conventional equipment which has been used for the prior art processes with fluorocarbons ·

The improvement of animal skins with dichloromethane provides substantial advantages by allowing the degreasing and cleaning of animal skins on large machinery without hardening the skin belt. This advantage is made possible by the low boiling point of dichloromethane and the possibility of processing the skins in this medium at atmospheric pressure · The proposed method not only makes the degreasing and cleaning process cheaper and more productive, but also significantly improves working conditions during further processing of such cleaned and degreased skins.

The process according to the invention is explained in more detail in the following examples.

Example 1

The Bowe 470 is loaded with 50 kg of greasy, dirty skins · Pumped from the working tank into a rotating - 3 - working drum 350 1 dichloromethane · Degreasing and cleaning by rotating the working drum for 10 minutes · Then remove the dichloromethane to the bottom distillation tank and cleaned skins ae centrifuging · The remaining remaining dichloromethane is also pumped into the bottom distillation tank · Drying of the skins and ee carried out at 48 ° C for 15 to 20 minutes · The dried skins are leveled after removal from the machine · During drying ae the dichloromethane (distillation) regenerates ·

Example 2

Loads 50 kg of dry, greasy, dirty skins into the Bèwe P 470 ae scrubber. · 350 liters of dichloromethane at a temperature of 15 ° C are pumped from the tempered working tank into a rotary working drum at a temperature of 15 ° C. Then the dichloromethane is pumped from the working drum into the bottom distillation tank and the cleaned skins are centrifuged · The remaining remaining dichloromethane is also pumped into the bottom distillation tank · The skimmed skins are dried at 48 ° C for 15 to 20 minutes · Dried skins are removed machines equalize · During the drying process and recover the dichloromethane by distillation ·

Example 3

The Bowe P 470 ae is loaded with 50kg of dry, greasy, dirty skins · 350 l of dichloromethane at 40 to 41 ° C is pumped from the tempered working tank into a rotary working drum. The working drum heating is set to 40 ° C on the thermostat. Degreasing and Skin cleaning by rotating the working drum takes 5 minutes. · The procedure is the same as in Example 2.

Claims (2)

SUBJECT OF THE INVENTION Process for degreasing and cleaning animal skins without undesirable hardening of the skin belt by treating the skins in an organic solvent, followed by conventional skins and drying of the skins, characterized in that the skins are degreased by washing in an organic solvent based on dichloromethane at 10 to 41 ° C for 3 to 15 minutes, after which the skins are dried at 20 to 50 ° C. 2. A method for degreasing and cleaning skins according to claim 1, characterized in that the skins are degreased at atmospheric pressure.