AN IMPROVED PROCESS FOR USE IN THE MANUFACTURE OF LEATHER
Year: 1878

page_text: LETTERS PATENT to Heary Harris Lake, of the Office of Hasoltine, Lake, &
Co., Patent Agents, Southampton Buildings, London, for the Invention of "AN
IMPROVED PROCESS FOR USE IN THE MANUFACTURE OF LEATHER." A commu-
nication from abroad by Pierre Chenon, of Paris, France.
Sealed the 21st February 1879, and dated the 27th August 1878.
PROVISIONAL SPECIFICATION left by the said Henry Harris Lake at the
Office of the Commissioners of Patents on the 27th August 1878.
HENRY HARRIS LAKE, of the Office of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS FOR USE IN THE
MANUFACTURE OF LEATHER." [A communication from abroad by Pierre Chenon,
of Paris, France.]
Hitherto in order to give strength and flexibility to leather it has been the
custom to subject the hides to the operations of tanning or tawing, and in some
cases to employ a process in which tallow, oil, greasy matters, and the like, are
used. These processes take a long time, and are costly, and in order to expedite
them chemical matters have been used, but with the disadvantageous result that
the tissue of the leather is injured, and the quality thereof thereby deteriorated,
rendering it not so strong as it should be.
The object of this Invention is to provide means whereby in the manufacture of
leather the full strength of the latter will be preserved, and any desired degree of
flexibility imparted to it, varying according to the different uses for which the
leather is designed.
In carrying the said Invention into practice I take the hide, either immediately
after the operations of unhairing and fleshing, or at any suitable time after these
operations have been effected, and after first subjecting the hide to the action of
water to soften it I treat it in water to which glycerine or some analogous sub-
stance or composition has been added. I prefer to use glycerine, and the quantity
varies according to the character or nature of the bide to be treated.

page_text: The employment of glycerine to soften leather is based upon a knowledge of the
property which glycerine possesses of attracting the moisture of the air, and of
consequently keeping the hide in a constant state of dampness.
I wish it to be understood that in mentioning substances analogous to glycerine
I mean such substances as possess the above-named property, provided they have
no corrosive action on the skin.
Amongst substances which may be used are chloride of calcium, sea salt, and the
neutral acetate of potash, but I prefer to employ glycerine.
The operation may be carried into practice in various manners, that is to say,
the softened hide may be immersed or plunged into the bath containing glycerino
or other substance diluted with water for a longer or shorter time, and then spread
out to dry; or the softened hide may be dipped into the bath and withdrawn
immediately; or the softened hide may be hung up vertically, having its lower
portion plunged in the bath, the hide being left in this position for a suitable length
of time. In this case the water in the part of the hide which does not dip into the
bath evaporates, and the pores of the hide having been thereby opened the glycerino
enters into these pores by the effect of capillary attraction, or an exchange between
the water and the glycerino takes place by the effect of a current.
I may also cause the glycerine or other substance to penetrate into the pores of
the hide by any other suitable means, as for example, by using a brush while the
hide is stretched on a frame or spread out on a table.
The duration of the immersion, dipping, and other operations will vary according
to the nature of the skin or hide, and according to the degree of flexibility which it
is desired to give to the leather. The leather thus impregnated or saturated with
glycerine or other suitable substance, and having been dried, possesses the desired
strength and flexibility, which qualities it retains to an indefinite period, and a
kind of transparency is imparted. Leather so prepared may be employed for all
the purposes for which leather as ordinarily prepared is used.
The process, according to my said Invention, produces leather of superior quality,
and possesses the advantage of being quickly effected, as it requires but ono single
operation after the operations of fleshing and unhairing have been effected.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Henry Harris Lake in the Great Seal Patent Office on the 27th
February 1879.
THE
HENRY HARRIS LAKE, of the Office of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED PROCESS FOR USE IN
MANUFACTURE OF LEATHER" A communication from abroad by Pierre Chenon, of
Paris, France.
Hitherto in order to give strength and suppleness or flexibility to leather it has
been the custom to subject the hides to the operations of tanning or tawing, and in
some cases to a process in which alum, tallow, oil, fatty matters, and the like are
used. These operations or processes are tedious and costly, and in order to expedite
them chemical matters have been used, but with the disadvantageous result that
the tissue of the leather is injured, its quality is deteriorated, and consequently its
strength is diminished.
The object of this Invention is the manufacture of leather by an improved pro-
cess, whereby its full strength will be preserved and any desired degree of flexibility
may be imparted to it, varying according to the different uses for which the leather
is designed.
In carrying the said Invention into practice I take the hide, either immediately
after the operations of unhairing and fleshing, or at any suitable time after these
operations have been effected, and after first subjecting the hide to the action of
water to soften the same, I placo it in water to which glycerine or somo analogous
substance or composition has been added (I prefer to use glycerine), the quantity
thereof being varied according to the character or nature of the hide to bo
treated.
The employment of glycerine to soften leather is based upon a knowledge of the
property which glycerine possesses of attracting the moisture of the air, and of
consequently keeping the hide in a constant state of dampness.
I wish it to be understood that in mentioning substances analogous to glycerine
I mean such substances as possess the above-named property, provided they have
no corrosive action on the skins; for instance, I may use chloride of calcium, sea
salt, or the neutral acetate of potash, but I prefer to employ glycerine.
The treatment of the leather may be varied, that is to say, the softened hide
may be immersed or plunged into the bath containing glycerine or other substance
diluted with water for a longer or shorter time, and then spread out to dry; or the
softened hide may be dipped into the bath and withdrawn immediately; or the
softened hide may be hung vertically with its lower portion immersed in the bath,
tho hide being left in this position for a sufficient length of time. In this case the
water in the part of the hide which does not dip into the bath evaporates, and the
pores of the hide having been thereby opened the glycerine enters these pores by
the effect of capillary attraction, or an exchange between the water and the
glycerine takes place by the effect of a current.
I may also cause the glycerine or other substance to penetrate into the pores of
the hide by any other suitable means, as for example, by using a brush while the
hide is stretched on a frame or spread out on a table.
The duration of the immersion, dipping, and other operations will vary according
to the nature of the skin or hide, and according to the degree of flexibility which it
is desired to give to the leather. The leather thus impregnated or saturated with
glycerine or other suitable substance, and having been dried, possesses the desired
strength and flexibility, which qualities it retains to an indefinite period, and it
will also have a kind of transparency. Leather so prepared may be employed for
all the purposes for which leather as ordinarily prepared is used.
The said improved process affords the means for producing leather of superior
quality, which I term transparent leather, and possesses the advantage of being

page_text: quickly effected, as it requires but one single operation subsequently to the opera-
tions of fleshing and unhairing.
Having thus fully described the said Invention as communicated to me by my
foreign correspondent, and the manner of performing the same, I wish it understood
that I claim, in the manufacture of leather the application or employment of
glycerine or analogous substances, whereby I accelerate the work and produco
leather of unimpaired strength, and which acquires and retains great suppleness or
flexibility, as above set forth.
In witness whereof, I, the said Henry Harris Lake, have hereunto set my hand
and seal, this Twenty-seventh day of February, in the year of our Lord One
thousand eight hundred and seventy-nine.
HENRY H. LAKE. (L.S.)