US1599358A

US1599358A - Process for removing the hair from green hides

Info

Publication number: US1599358A
Application number: US737607A
Authority: US
Inventors: Bergmann Max; Immendorfer Eugen; Immendorfer Alice
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-09-19
Filing date: 1924-09-13
Publication date: 1926-09-07
Anticipated expiration: 1943-09-07

Description

' sulphide:

Patented Sept. v7, 1926."

UNITED STATES PATENT OFFICE.

mix nnnemxnn, nuenn mmnnnonrna, AND ALICE nmnnnonrnn, min ooonson,

- or mmsnnn, enrmnnr.

rnocnss non nnmovme THE .nnm rnoni GREEN nrnns.

No Drawing. Application filed September 13, 192*, Serial No. 737,607, and in Germany September 19, 1923. i

It has become known to use alkalior earth alkali sulphides for removing the hair from green hides. It is further known to use forthe same purpose nitrogen bases like ammonlaalone, for instance in closed chamhers and in the heat. The first mentioned process more or less affects the hair especially the wool, and the last mentioned proc'. esses are cumbersome and require expensive installations It has further been roposed to use a mixture of sodium sulp ids and of sodium sulplihydrate' to which such uantities of ammonia carbonate are added,

t at the sodium sulphhydrate is converted into-equal parts of sodium sulphide and of ammonia sulphide. Consequently in this process also considerable quantities of active sulphide pr sodium remain present and exert their unfavorable, decomposing action on the hair, at the roots as well as at the parts exposed above the skin.

' We now have found'that the above stated inconveniences can beavoided by using sulphides of inorganic or organic. nitrogen bases which are free from active alkali sulused for the slackening process, said liquids no more containing any active free alkali Further we have .found that an unhairing liquid, combined from solutions of ammo nia sulphide and soluble silicates, is specially well suited for this purpose. 'A liquid ofquestion and to t e desired leather to be obtained.

this kind frees the hides and skins from hair within-a few hours and does not afiect I the valuable skin substancenor the hair.

- Emamples. 1.To,free iieec es frdm wool the slacken ing liquid is prepared as "follows:

20 liters of commercial ammonia sulphide,

.50 200 liters of aqueous ammonia,solution (of 0.910 spec. gravity) and- 20 hectoliters of.

water are mixed to 'ethen Into this solution the corresponding quantity of sheep-' skins or" fleeces is immersed, the quantity of than indicated.

steeping liquid amounting for instance to 155 five times the weight of the hides. The temperature is preferably maintained at 25 C.,'

and after 1 to 2 days the skins will release the hair quite readily. The wool remains 1n a very good condition.

2.Instead' of the free ammonia the 'corresponding quantity of pyridin of 1' liter of technical pyridin for one liter or M sulphide.- The composition mayvary con- 7 siderably and be, without prejudice, stronger So much of thisgunhairing liquid is used that the hides are well covered. .After 5 tot hoursalready, the mass having been agitated repeatedly, the hides will let loose the hair readily, this loosening of the hair being further improved within 1 to 2 days. The skin is not afiected at all but comes out of the process at a very clear state. The woolis'of excellent softness and good touch and proves tocontain the elastin yet in unaltered state. It difl'ers not in the least 4 from good fleecing.-

The treatment of other kinds of hides may 00 I be carried out in a similar manner, with convenient modificatio of theprocess. ,In all these cases the working prescriptions for the unhairing process must be adapted to t e special working rocess of the tannery in quality for the Instead of ammonia sulphide sueh salt mixtures may be employed which when dis-- solved will form ammonia sulphide, .{s for ing in immersing the hides in a solution containing sulphides of nitrogen bases and being free of active alkali sulphide.

2. A process .for unhairing hides consisting in immersing the hides in a solutioncontaining sulphides of inorganic nitrogen bases and being free of active alkali sulphide.

3. A process for unhairing hides consisting in converting alkali'sulphide with at least the equimolecular quantity of salts of nitrogen bases into sulphides of said nitrogen bases, and immersing the hides in the solution thus obtained.

4. A process for unhairing hides consisting in converting alkali sulphide with at least the equimolecular quantity of salts of inorganic nitrogen bases into sulphides of said inorganic nitrogen bases, and immersing the hides in the'solution thus obtained.

5. A process for unhairinghides consisting in immersing the hides in a solution containing sulphides of nitrogen bases and soluble silicates. I

6. A process for unhairing hides consist ing in .immersin the hides in a solution containing sulplii es of inorganic nitrogen bases and soluble silicates.

' 7. A process for unhairing hides consist.- ing in immersing the hides in a solution contaming ammonium sulphide and'a soluble silicate. 8. A process tor unhairing hides consisting in converting alkali sulphide with at least the equimolecular quantity of ammoniasalt into ammonium sulphide, adding a soluble silicate thereto, and immersing the hides in the solution thus obtained.

In testimony whereof we have hereunto set our hands.

Prof. MAX BERGMANN. Dr. EUGEN IMMENDGRFER.

Dr. ALICE lMMENDdRFER, ne GOODSON. i