US1909790A - Tanning process - Google Patents

Description

' uing liquor formed from Patented May 16, 1933 UNITED STATES PATENT OFFICE Y FREDERICK A. VOGEL, OF MILTON ERNEST, ENGLAND; JESSIE M. VOGEL EXECUTRIX. OF

SAID FREDERICK A. VOGEL, DECEASED, ASSIGNOR, BY MESNE .ASSIGNMEN'IS, TO EDWIN B. H. TOWER, JIL, OF MILWAUKEE, WISCONSIN I TANNING PROCESS No Drawing. Application filed June 10,

The present invention relates to a tanning process such as employed for tanning an animal hide or pelt into leather.

According to the ordinary vegetable or -chrome tanning process employed in practice,

the hide or pelt is prepared or made ready to be tanned by being delimed or bated to eliminate therefrom the lime employed to remove its hair, and then it is subjected to tannage for a prolonged time or period in vegetable or chrome tanning liquor to convert or transform its tannable substance into complete leather.

The prctannage which has heretofore been proposed in such a process-to lessen the time to produce complete leather has resulted inthe ultimate leather being impaired in quality and unsuitable for ordinary service.

The present invention has for its object to provide a tanning process which will tan a hide into leather of the same or better quality in less time than the ordinary tanning process.

Another object is to provide a tanning process which will produce strong, pliable, and durable leather in less time than the ordinary tanning process.

Another object is to provide a tanning process which will retain in thehide for trans-' formation into complete leather the tannable substance before eliminated and lost in deliming the hide.

Another object is to provide a tanning process which will produce from a given hid leather of more weight and area.

Another object is to provide a tanning process which will keep the hide in condition to have the tanning agent readily difi'use throughout its entire tannable substance.

According to this invention as ordinarily practiced, a limcd hide or pelt which has had its surface. lime eliminated or removed is pretanned for a limited period in a pretanaldehyde, such as formaldehyde, and sulfite cellulose extract to fix or set its tannable substance and commence transformation thereof into leather, and then the hide thus pretanned int'o partial leather is tanned until its tannable substance is converted or transformed into complete leather.

1924. Serial No. 719,109. 1

In order to explain the invention further, an example thereof as applied in practice to vegetable tanning is hereinafter explained.

A limed hide or pelt, which has been dehaired and has .had its surface or excess lime removed by lactic acid, is subjected to pretannage fora limited period in a pretanning liquor to set or fix its tannable substance and commence rapid transformation thereof into leather.

The pretanning liquor is in essence an aldehyde, such as formaldehyde, and sulfite cellulose extract diluted in Water to a suitable solution. i

The formaldehyde and the sulfite cellulose extract are such as ordinarily employed In tanning in other relations, for instance, formalin and spruce extract.

When the hide is subjected to the pretanning liquor the formaldehyde which is a rapid tanning agent fixes and sets its tannable substance and commences rapid transformation thereof into leather'and the sulfite cellulose extract which is an acid medium keeps the hide open and in condition to have the pretanning liquor and likewise the subsequent ordinary tanning liquor readily diffuse throughout its entire tannable substance.

If the pretanning liquor did not have the by increasesthe ultimate yield of leather from the hide.

'hen the hide has been pretanned for a limited period of about five or six hours it is then tanned inordinary tanningliquor until its tannable substance is converted or transformed into complete leather.

As compared to the ordinary process, the

tanning process herein explained will tan 9.

hide to produce complete leather of equal or better quality in much less time and the leather yielded from such hide will have more weight and area.

The present tanning process as explained herein to exemplify its characteristics may be practiced and modified in various ways according to the conditions without in any wise departing from the invention as defined in the hereinafter claims.

The invention set forth in the foregoing specification is hereby claimed as follows: 1. Atanning process, comprising surface deliming a hide after its hair has been removed by lime, then subjecting the hide for a limited period to pretannage in mixed aldehyde and sulfite cellulose extract to commence transformation of its tannable sub 4 stance into leather, and thereafter subjecting the hide thus pretanned to tannage in a vegetable tanning liquor for a sufficient period to transform its tannable substance into complete leather.

2. A tanning process, comprising surface deliming a hide after its hair has been removed by lime, then subjecting the hide for a limited period of pretannage in mixed formaldehyde and sulfite cellulose extract to commence transformation of its tannable substance into leather, and thereafter subjecting the hide'thus pretanned to tannage in a vegetable tanning liquor for a suflicient period to transform its tannable substance into complete leather.

Signed at the city, county, and State of New York, this 6th day of une, 1924.

FREDERICK A. VOGEL.