Improvements in and connected with Tanning Hides, Skins, and the like.
Year: 1896

page_text: Date of Application, 26th Oct
1896
Complete Specification Left 20th May. 1897-Accepted, 26th Oct., 1897
Complete Specification Left 20th May 1897-Accepted, 26th Oct., 1897
PROVISIONAL SPECIFICATION.
Improvements in and connected with Tanning Hides, Skins, and the
like.
We, JAMES THOMAS MCQUINN of Beacon Hill View, Weston Point, Runcorn,
in the County of Chester, Tanner, and EDMUND CALDWELL, of Carlton Villa,
Stockton Heath, Warrington in the County of Lancaster, Director, do hereby
declare the nature of this invention to be as follows:
This Invention relates to a new or improved method of and means for tanning
hides, skins and the like, the adoption of which results in an economy of labour
and permits the results to be obtained in less time than at present.
In proceeding according to these Improvements, the hides skins or the like are
subjected to the usual preliminary treatment of dehairing and cleansing. They
are then immersed in a bath of diluted Sulphuric Acid for a short time, and, after
removal from the acid bath, they are squeezed, pressed or rolled to remove super-
fluous liquid. The thus partially dried hides or skins are now immersed in the
tanning bath which is composed of a solution of Bichromate of Potassium,
Canella, Socotrine Aloes, and Sulphuric Acid in water. They remain in this
bath for a period varying from less than 30 minutes for the thinnest skins, to
over 6 hours for thick hides, and on removal after this comparatively very short time
the tannage will be found to be completed, and the goods may be washed dried,
rolled and otherwise treated in the usual manner.
94th day of October AD 1896.
W. E. HEYS & SON,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in and connected with Tanning Hides, Skins, and the
like.
We, JAMES THOMAS MCQUINN of Beacon Hill View, Weston Point, Runcorn,
in the County of Chester, Tanner, and EDMUND CALDWELL, of Carlton Villa,
Stockton Heath, Warrington in the County of Lancaster, Director, do hereby
declare the nature of this invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the fallowing
statement:
This Invention relates to a new or improved method of and means for tanning
hides, skins and the like, the adoption of which results in an economy of labour
and permits the results to be obtained in less time than at present.

page_text: In proceeding according to these Improvements, the hides skins or the like are
subjected to the usual preliminary treatment for depilation and cleansing. They
are then immersed in a bath of dilute sulphuric acid for a short time and after
removal from the acid bath they may be squeezed, pressed or rolled to remove super-
fluous liquid. The thus partially dried hides may then be immersed in the
tanning bath which is composed of a solution of or containing an alkaline
bichromate, canella, aloes, and sulphuric acid in water. They remain in this
bath for a period varying from less than thirty minutes for the thinnest skins, to
over six hours for thick hides and on removal after this comparatively short time,
the tannage will be found to be completed, and the goods may be washed, dried,
rolled and be otherwise treated in the usual manner.
The depilated and cleansed skins or hides remain for only a short time in the
preliminary acid bath, the duration of the treatment being determined by the
strength of the bath and by the thickness and nature of the material to be
tanned. For ordinary hides the acid bath may be composed as follows:-
Ordinary rectified sulphuric acid, -
Water,
2 volumes.
8 volumes.
As soon as the solution is cool the hides may be immersed in it for from three to
five minutes. On removal from the acid bath the hides are preferably rolled
between wooden rollers.
The acidified hides are then placed in the tannage bath the ingredients in
which may have their proportions varied according to the colour and nature of
the desired product. If however the quantity of aloes be reduced, it is desirable
to proportionately increase the quantity of bichromate. Socotrine and Cape aloes
give the best results, especially when they are used in combination.
working bath may be made up with the following proportions:-
Canella,
Socotrine aloes,
Cape aloes
Potassium bichromate,
Commercial sulphuric acid,
2 pounds;
1 pound;
8 pounds;
8 pounds;
7 pounds;
A gool :
3
Water
6 gallons.
The stated proportion of sulphuric acid is suitable for "upper leather"; for solo
leather it may be increased to double, and be varied otherwise according to the
material. The solution thus made with 6 gallons of water, will suffice for the 3
tannage of about 64 pounds of raw material. Although all the materials may be
brought into solution in the first place, it is generally advisable to reserve a por-
tion of the aloes and canella to sprinkle between the hides or skins as they are
laid in the bath. It will be understood that the tannage must be effected in
pits or tanks constructed of a material such as stone or concrete, as will not be 4
effected by the action of the liquor. The sulphuric acid is best added last of all
in the tan-pit and the solution should be well mixed before the hides or skins
are immersed. It will be understood that the acid should be added gradually
and that the mixture should be allowed to cool. If the hides or skins are kept
apart in the bath by known means or even by the fragments of aloes and canella 4
sprinkled between them as herein before described, the action of the bath will
be facilitated.
In tanning for sole leather, the hides may be lifted direct from the acid bath
to the tannage bath without any intermediate rolling.
The hides and skins may be treated in the tannage bath in other methods than 50
that hereinbefore referred to, but it is, in all cases, desirable to take such pre-
cautions as are well understood to ensure the penetration of the liquid to both
surfaces of the skins, and its circulation also.
If the skins or hides be treated with soap solution after tanning without inter-
mediate washing or treatment, the acid will decompose the soap and become 55
neutralised whilst the oleic or other fatty acid of the soap will enter the leather

page_text: and render it supple or partly curry it. Otherwise, the acid may, if desired, be
neutralised by any suitable alkali after the tannage is complete.
The tannage bath may be used over and over again if there be added to it
after each use, fresh quantities of aloes, canella and acid and about half the quantity
of bichromate, but this will have to be determined in each case by the temporary
condition of the bath.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is :-
1. The hereinbefore described process for tanning hides skins and animal
membranes which consists essentially in treating the hides or the like after de-
pilation and cleansing, in a bath of diluted sulphuric acid and subsequently in a
bath containing aloes, canella, an alkaline bichromate and sulphuric acid;
substantially as set forth.
2. As new substances, the new skins and the like produced by the process here-
inbefore described and claimed by the first claiming clause.
Dated this 19th day of May AD 1807
W. E. HEYS & SON,
Agents for the Applicants.