IMPROVEMENTS IN THE MANUFACTURE OF LEATHER
Year: 1882

page_text: LETTERS PATENT to John Henry Johnson of 47 Lincolns Inn Fields in the
County of Middlesex Gentleman for an Invention of 20 IMPROVEMENTS IN
THE MANUFACTURE OF LEATHER Communicated to him from abroad by
Ambrose G. Fell of New York City in the County and State of New York in
LITY I
"
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents on the 15th August 1882.
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN THE MANUFACTURE OF LEATHER a communi-
cation to me from abroad by Ambrose G. Fell of New York City in the County
and State of New York in the United States of America
This Invention has for its object the manufacture of a new kind of leather
which in its physical or commercial characteristics shall be very similar if not
identical with that obtained from the skins of animals and applicable to the
same uses differing therefrom only in its chemical constituents and in that respect
but slightly.
This leather is not termed "artificial" for by so doing inferiority might be
implied whereas in some respects this new leather is superior to the ordinary
material The material from which this improved leather is prepared may be
termed an "artificial skin" but the leather itself made therefrom is real leather,
for leather whether produced by the old method of treating hides or by the new
process herein described is for all practical purposes and in chemical parlance
identical consisting of an insoluble imputrescible tough homogeneous sheet of
gelatinous tissue or fibre.
In the processes of making ordinary leather the skin of an animal having been
deprived of its extraneous matter by the usual methods and being ready for
conversion into the leather of commerce consists of a web or tissue of fibre, filled
in with a substance chemically known as ossein and the processes of tanning to
which the said skin is afterwards submitted are twofold in their object firstly to
D
C

page_text: convert the ossein into gelatine by a rearrangement of its chemical atoms and
secondly to combine the fibre with the gelatine thus produced forming therewith
the insoluble imputrescible material known in commerce as leather.
According to the present Invention instead of the natural homogeneous sheet of
fibre and gelatine known as skin a sheet of fibre and gelatine is prepared as
hereafter described which is also perfectly homogeneous. The improved process
however affords the very great advantage of a choice of fibre best adapted to
the intended uses of the ultimate leather and another advantage gained is the
uniformity of product both as regards evenness of thickness and strength.
Having provided a substitute for the skin and if in the course of its
preparation some agent has not been introduced to take the place of a subsequent
tanning then the Inventor proceeds in a similar manner to the ordinary method
employed for converting skins into leather to wit, it is tanned or chemically
speaking the artificial skin is subjected to the action of such chemicals or
compounds thereof as shall render its gelatine insoluble imputrescible flexible
and so on
The means employed for this purpose may be any of those employed for
treating natural skins for the same purpose the method hereafter specifically
described is preferred.
The object of the present Invention is to produce a leather which while
possessing all the desirable characteristics of that prepared from the skins of
animals shall in addition thereto be uniform in thickness and strength and capable
of being made in large or continuous sheets with straight edges which will enable
it to be cut to much better advantage than is possible with the irregular outline of
a skin.
In carrying the invention into effect the following is the procedure.
A homogeneous pulp of fibre and gelatine is first formed by any convenient
means employing any description of fibre but preferring the long fibre of raw
cotton Now if simply coating the fibre and fitting up the interstices between said
fibre and sticking them together were all that was aimed at in this process this
could be effected by simply dipping washing or any other application of the
gelatine to the said fibre but it is the object of this process to make the combination
of fibre and gelatine form one homogeneous material in which the identity of the
fibre or tissue is for the time being lost in the same manner as the identity of the
fibre of a natural skin is lost previous to tanning This marks the great difference
between the first step of this new process and those wherein a fabric or material is
merely steeped in or treated by a gelatine compound
Fibre whether animal or vegetable will mix with a gelatine solution but by
reason of the atmospheric air oleagineous and other elements which occupy the
interior of each individual fibre the gelatine is prevented from doing more than
merely surrounding said fibre and this only with difficulty but by expelling the
air and foreign matter from the fibre an intimate and homogeneous union is
effected With this object in view the fibre is first subjected to the action of boiling
water or chemical solution and having thus displaced the air and other elements
and while it is still wet and hot from said treatment it is admixed with the
gelatine compound with which it will now gradually and completely combine
The artificial skin or compound of fibre and gelatine is preferably formed as
follows.
Raw cotton or wool or any other loose fibre is taken and by suitable means it
is formed into a light fluffy web If cotton be the fibre chosen it is formed into
such a web by means of a machine similar to that usually employed to form
cotton batting but for the purposes of this process the cotton or other fibre is kept
as loose as possible the width and length of the said web being governed by the
width and diameter of the drum employed in the said machine or the fibre may be
run off in continuous lengths as hereinafter described and the thickness of the web
is regulated by the amount of cotton allowed to accumulate on the said drum as is
well understood in the arts The cotton deposited on the drum of the batting

page_text: machine is very loose and too tender to be handled in the manner of handling the
smaller and firmer rolls of batting produced for ordinary purposes and cannot be
rolled upon itself and then unrolled without loss of evenness of thickness the web
is therefore rolled from the drum of the batting machine on some other material
that known as burlaps answering the purpose very well
To accomplish this a roller is provided in front of the batting machine and to
this roller is conducted one end of the burlaps employed and on this burlaps the
cotton fibre web from the machine is laid and by revolving the roller the web and
the burlaps are wound together on the said roller in such a manner as to have a
thickness of burlaps between each thickness of fibre care being taken not to wind
the web on the roller too tightly as by so doing it would retard the process to which
it is next subjected. The burlaps should be a little wider than the sheet of fibre
web and the roller on which both are wound should be longer than the width of
the burlaps
Having wound a sufficient length of the web on the roller as described the roll
is next secured from unrolling by any convenient means tying them with cords at
say twelve inches apart answers very well but whatever means may be employed
for this purpose care should be taken not to compress to the roll to such an extent
as to retard the next operation
The roll is placed next in a bath of boiling water or a weak solution of suchi
chemical agent as shall act some desired part in the next operation as hereinafter
explained. When water alone is employed in this bath the chief object is to
thoroughly saturate the fibre therewith and by doing so to displace and drive out
the atmospheric air and foreign matter that is held in and between the said fibre
for if such result be not accomplished by these or other means it will be found
very difficult if not, impossible to effect a complete combination of the fibre with
the gelatine which is subsequently applied
The boiling should continue for one or more hours according to the thickness
of the fibre web and size of the roll under treatment but having accomplished this
end the hot saturated roll is taken from the boiling bath and allowed to drain
until most of the water that will run off has done so.
The rolls are next placed in a bath of water gelatine and bichromate of potash.
The proportions are not material but for general practical results this second bath
is compounded in the following proportions water six gallons gelatine eight pounds
and bichromate of potash three por cent of the gelatine. The chromic salt may be
left out at this stage and applied afterwards or may be entirely substituted in like
manner other agents employed in the after part of the process may be introduced
at this stage with advantage according to the final effect or character of the
perfected material desired as hereafter described.
The object of using the bichromate of potash in connection with the gelatine is to
render the latter inore or less insoluble when exposed to light as is understood in
photographic art or the same effect in connection with the chromic salt is produced
by elevation of temperature or at the ordinary temperature when sufficient time
is allowed which may be days weeks or months according to circumstances Instead
of having a separate vessel for the second bath the fluid of the first bath could be
drawn off and the same vessel used for the second bath but it is preferred to
proceed as described.
As to the character of the gelatine employed although that known in com-
merce under the term glue answers the purpose well still it is well known in
chemistry that the strength and durability of the gelatine is greatly affected
by high temperature or by frequent dissolving
It is therefore preferred to obtain the gelatine direct from any of its sources of
production and while still in solution as obtained in the ordinary method of its
production to directly apply it to the purposes of this process as set forth thus
obtaining a stronger and more durable final result
Having compounded the second bath in about the proportions named there is
immersed in it at a temperature of 120° F more or less the roll containing the

page_text: fibre previously prepared as described and it is allowed to remain in the said
gelatine bath for a sufficient time say two or more hours until the water or
solution with which the fibre has been previously saturated is completely replaced
by the gelatine compound The roll is next removed from the gelatine bath and
allowed to drain until most of the surplus liquor runs off The fibre held between
the burlaps is next placed on a slab or sheet of glass or other material upon which
it is unrolled so as to bring the gelatinized fibre next to the surface of the glass or
other material employed.
Sufficient pressure of any kind is now brought to bear on the burlaps to
force the gelatinous mass into as close contact as possible with the glass or other
surface on which it is spread the said contact being well effected by brushing or
rolling
The fibre and the gelatine are now in the condition of a sheet of pulpy jelly
and if the fibre has been thoroughly combined with the gelatine it is at this stage
almost indistinguishable therefrom having been rendered more or less transparent
by its union with the said gelatine.
If a solid and compact leather be desired more of the gelatine compound is
poured over the burlaps or their equivalent and spread evenly thereon and it
will run through the said burlaps or other material and mingle with the
gelatinous mass spread beneath it increasing the proportion of gelatine therein
contained.
The burlaps is now removed and the gelatinized fibre allowed to remain on
the glass or other material until dry which will require twelve or more hours
according to thickness of material temperature and ventilation with which it is
surrounded.
The semi-liquid and pulpy condition of the gelatinized fibre as it is placed on
the glass slab is such that it cannot be well brushed or rolled without disturbing
the uniformity of its arrangement and hence the necessity of using the sheet of
burlaps or other material as an intermediate means to allow of distributing the
gelatine compound poured on âs described.
As
A further degree of solidity can be added to the material by again treating it
with the gelatine compound after drying and still further increased pressure.
a material on which to spread the gelatinous fibre glass or other more or less
translucent material is preferred so that light can penetrate through the said
material and produce on, both the lower and the upper surface of the said
gelatinous fibre the effect of light due to the Chemical properties of the chromic
salt contained in the gelatine rendering said gelatine insoluble. It is necessary
that the exposure to light be continued after the material has become dry for it is
while dry that the insoluble effect is most readily and effectually produced the
colour of the light transmitted to the gelatinous fibre containing the chromic salt
or its equivalent is also important. For instance if the colour be blue the action
will be slow, if yellow or ruby the said action will be almost entirely arrested.
A material void of colour is therefore most desirable through which to transmit
the light for this purpose white glass being the best. The gelatinous fibre may be
spread on some other surface which need not be at all transparent but in that
event the material should be exposed to light after removal therefrom but if the
gelatinized fibre be spread on the glass as described and while thereon exposed to
the action of light that surface which is next to the glass becomes inuch inore solid
and compact in its texture and when removed from the said glass as hereafter
described presents two surfaces distinctive in their character. The surface which
was next the glass is smooth and compact and not inclined to shrink when
dampened and redried while the other surface which formed the uppermost side
of the gelatinous fibre as it lay on the glass is even but not smooth and will
contract when dampened and redried. In these respects the material corresponds
with the skin of an aminal the smooth side representing the outer or grain side
and the other side corresponding with the flesh side of said skin.
In drying it will be found that the mass of gelatinous fibre has become more

page_text: transparent and very greatly lessened in thickness the whole of its contraction
being in that direction thereby securing a greater amount of strength in proportion
to its thickness It is also very hard and adheres very tenaciously to the surface
on which it was dried. To remove it however it is only necessary to moisten the
material in any convenient way by immersion sprinkling washing or other means
until softened through its entire thickness.
Now if the potash bichromate was admixed with the gelatine bath as described
then water will answer to soften and remove the artificial skin from the surface
on which it was dried or if a greater degree of insolubility be desirable this water
may contain alum or chrome-alum or any other agent capable of producing the
desired end and if the chromic salt or its equivalent was not admixed with the
gelatine compound comprising the second bath then this stage of the process affords
a good opportunity for its introduction.
A solution of said salt, say one containing three per Cent of bichromate is used
for softening the artificial skin as it lays on the surface on which it was dried
When sufficiently moistened it is easily removed by rolling it up or in any other
convenient way. If a solution of the chromic salt has been employed in the
removal the artificial skin is next dried in any way and exposed to light for a few
hours but if water has been the medium of removal the skin may be placed in the
third bath of tanning preparation hereinafter referred to although a greater degree
of compactness is assured by drying it before its subjection to this final bath or if
the gelatine contains or has been treated with the chrome salt or its equivalent and
thus rendered insoluble and imputrescible the leather at this juncture may be
completed by simply rendering it opaque and flexible Opacity may be imparted
by soaking in a solution of any carbonate (say carbonate of soda) or one of many
other methods may be employed. For suppleness glycerine may be added in the last
mentioned treatment or at some other stage in the process.
Instead of boiling the roll of fibre in water a solution may be employed such as
that of alum, a salt of iron, or any agent capable of rendering the gelatine sub-
sequently applied more insoluble or to facilitate the displacement of the air and
other contents of the fibre under treatment or the first bath may possibly be
substituted by placing the fibre in an air tight vessel and exhausting the air
therefrom by means of a vacuum and the second bath compound applied to the
fibre while in said vacuuni. Or the gelatine compound may be directly applied to
the loose fibre and forced into and between it by pressure or any other means may
be employed The method described of successive baths produces a uniform and
reliable result the fibre becoming indistinguishable from the gelatine the whole
forming a transparent sheet of perfectly gelatinized fibre one homogeneous
substance such as is very difficult if not impossible to produce by other means
although the product by the other methods described may suit well for some
purposes.
Now I have described the preparation of the artificial skin which forms the
basis of the new kind of leather and this material has so close a resemblance to a
natural skin that it may be finished by any of the methods employed for treating
skins of animals to produce leather or the said treatment requiring but slight
modification.
If it be determined to finish the leather in the ordinary way of tanning it will
be found that it has the very great advantage of not being affected by elevation
of temperature, as the natural skin is hence the tanning solutions where with it is
treated may be employed at a high heat and thus effect in a few hours what
would otherwise require days. If, however a more porous or spongy leather be
required it is preferred to allow more time at a lower temperature.
The tanning preparation for the final treatment or tanning is preferred to be
composed of water containing equivalent to say five per cent of tannic acid and
twenty-five per cent of glycerine or other agent capable of imparting flexibility-
The tannic acid may be added as such or bark or sumack nutgalls or any other

page_text: compound or material containing tannic acid or its equivalent may be employed
instead thereof.
But the Invention is not limited to the use of tannic acid since any ingredient
agent method or methods known to produce the effect designated and understood
under the general terms of tanning and tawing may be employed instead.
Owing to the aforementioned peculiarity of the contractibility of one side the
artificial skin and the incontractibility of the side next to the surface on which it
was dried this leather may be grained in like manner to a natural skin so that
when the said material is rolled and rubbed as is understood in the method of
graining the one side contracts and the other side wrinkles to accommodate said
contraction the form of said wrinkles being governed by the direction in which the
The
skin is rolled and manipulated according to the skill of the operator.
peculiarity of these wrinkles constitute the different styles of graining as understood
in the arts
Many modifications of the process may be made with desirable results according
to the effect aimed at. For instance, when the gelatinous fibre is placed on the
surface on which it is intended to be dried, no additional gelatine solution may be
added as set forth, in such event the artificial Skin when dry will be less solid,
more spongy and soft.
If a finished leather be desired of such thinness as is impracticable to be formed
out of so frail and tender a web as that formed by the fibre employed, the following
plan can be made available. Proceed as already set forth with the production of
the sheet of gelatinous fibre and place it on the glass or other material as described;
next lay on it the sheet of burlaps, or other material and upon this bring to bear
any convenient pressure such as that of a roller which treatment tends to concen-
trate the amount of fibre in the body of the artificial skin and forces a larger
proportion of gelatine to the two surfaces. Next dry the Skin as usual and when
dry remove in the manner set forth, and while still wet, it will, with care, evenly
split, the concentration of the gelatine on the surfaces strengthening them causing
the material to separate in the middle where it is weakest Having thus secured
as thin a Skin as desired it can be tanned, tawed or finished by one method in this
condition or additional gelatine compound may be applied to the split side according
to the style of leather required.
Any thickness of leather or artificial skin can be secured by regulating the
thickness of the fibre first employed or by uniting two or more thicknesses of the
material at any stage of the process most convenient.
The character of the leather may also be varied by removing the gelatinous fibre
from the surface upon which it is spread before it has become dry and completing
the drying without contact with any surface or it might be dried direct from the
roll without having been spread on any surface; in either case the dried artificial
skin will not have a smooth or grained side but will have two porous or flesh sides,
which can be made smoother by coating with the gelatine compound used in the
second bath; but it will be readily understood that the surface thus applied is not
homogeneous with the body of the leather, but will be of the nature of a similar
application made to other material. If the gelatine compound, thus applied to the
surface, be colored and the material while still damp be brought into close contact
with a glossy surface and allowed to dry thereon the surface of the finished leather
will resemble the ordinary Patent or enamelled leather.
One feature of the leather which it possesses in common with leather made from
Animals' skins and which recommends it for many applications in the arts, is its
elasticity when stretched in any direction especially while damp. This quality is
due to the homogeneous combination of unbroken separate fibres with gelatine
which quality could not be had with a broken fibre as in paper or the pulp whereof
it is made or with a woven or spun fabric where the warp or woof would be opposed
to such elasticity.
It will be understood that by the term "homogeneous compound of fibre and

page_text: Gelatine" is not meant that the former is dissolved so that its identity is entirely
lost as fibre, since if this were the case the resulting product would not be true
leather, in which the fibre, fibrine or tissue, although being one substance, intimately
but mechanically mixed with the gelatine, possesses its individual existence and
imparts the structural characteristics as fibre to the finished article.
The leather made by this Invention is like the true leather made from natural
skins, in that it contains numerous ramifying fibres, intersecting one another in
every position and in this it is different from the so called artificial leather which
has been heretofore made by coating woven fabrics with gelatine. Such artificial
leather does not possess, as does the improved product, the properties of real leather,
namely, intimate and homogenous mixture of the fibre and gelatine, capability of
stretching equally in every direction of being split and of having its edges
" skivered."

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Henry Johnson in the Great Seal Patent Office on the
10th February 1883.
"
JOHN HENRY JOHNSON of 47 Lincolns Inn Fields in the County of Middlesex
Gentleman "IMPROVEMENTS IN THE MANUFACTURE OF LEATHER a communi-
cation to me from abroad by Ambrose G Fell of New York City in the County
and State of New York in the United States of America
This Invention has for its object the manufacture of a new kind of leather,
which in its physical or commercial characteristics shall be very similar if not
identical with that obtained from the skins of animals and applicable to the same
uses differing therefrom only in its chemical constituents and in that respect but
slightly.
This leather is not termed "artificial" for by so doing, inferiority might be
implied, whereas in some respects this new leather is superior to the ordinary
material. The material from which this improved leather is prepared may be
termed an
"artificial skin" but the leather itself made therefrom is real leather;
for leather, whether produced by the old method of treating hides, or by the new
process herein described is for all practical purposes and in chemical parlance
identical, consisting of an insoluble imputrescible tough homogeneous sheet of
gelatineous tissue or fibre.
In the processes of making ordinary leather, the skin of an animal having been
deprived of its extraneous matter by the usual methods and being ready for con-
version into the leather of commerce consists of a web or tissue of fibre, filled in
with a substance chemically known as ossein and the processes of tanning, to which
the said skin is afterwards submitted, are two-fold in their object, firstly, to convert
the ossein into gelatine by a re-arrangement of its chemical atoms, and secondly, to
combine the fibre with the gelatine thus produced, forming therewith the insoluble
imputrescible material known in commerce as leather.
According to the present Invention, instead of the natural homogeneous Sheet of
fibre and Gelatine known as Skin, a Sheet of fibre and gelatine is prepared as here-
after described which is also perfectly homogeneous-The improved process however
affords the very great advantage of a choice of fibre best adapted to the intended
uses of the ultimate leather; and another advantage gained is the uniformity of
product both as regards evenness of thickness and strength.
Having provided a substitute for the Skin and if in the course of its preparation
some agent has not been introduced to take the place of a subsequent tanning then
the Inventor proceeds in a similar manner to the ordinary method employed for
converting skins into leather, to wit; It is tanned or chemically speaking, the
artificial Skin is subjected to the action of such chemicals or compounds thereof as
shall render its gelatine insoluble imputrescible inflexible and so on.
The means employed for this purpose may be any of those employed for treating
natural Skins for the same purpose but the method hereafter specifically described
is preferred.
The object of the present Invention is to produce a leather which while possessing
all the desirable characteristics of that prepared from the skins of animals shall in
addition thereto be uniform in thickness and strength and capable of being made
in large or continuous sheets with straight edges which will enable it to be cut to
much better advantage than is possible with the irregular outline of a Skin.
In carrying the Invention into effect the following is the procedure:
A homogeneous pulp of fibre and gelatine is first formed by any convenient

page_text: means, employing any description of fibre but preferring the long fibre of raw
cotton. Now, if simply coating the fibre and filling up the interstices between said
fibre and sticking them together, were all that was aimed at in this process, this
could be effected by simply dipping, washing or any other application of the
gelatine to the said fibre, but it is the object of this process to make the com-
bination of fibre and gelatine form one homogeneous material in which the
identity of the fibre or tissue is for the time being lost in the same manner as the
identity of the fibre of a natural skin is lost, previous to tanning.-This marks
the great difference between the first step of this new process and those wherein a
fabric or material is merely steeped in or treated by a gelatine compound.
Fibre, whether animal or vegetable, will mix with a gelatine Solution, but by
reason of the atmospheric air, oleagineous and other elements which occupy the
interior of each individual fibre, the gelatine is prevented from doing more than
merely surrounding said fibre and this only with difficulty, but by expelling the
air and foreign matter from the fibre, an intimate and homogeneous union is
effected. With this object in view, the fibre is first subjected to the action of boiling
water or chemical solution and having thus displaced the air and other elements
and while it is still wet and hot from said treatment it is admixed with the
gelatine compound with which it will now gradually and completely combine.
The artifical Skin or compound of fibre and gelatine is preferably formed as
follows:
Raw cotton or wool or any other loose fibre is taken and by suitable means it is
formed into a light fluffy web. If cotton be the fibre chosen, it is formed into such
a web by means of a machine similar to that usually employed to form cotton
batting, but for the purposes of this process, the Cotton or other fibre is kept as
loose as possible, the width and length of the said web being governed by the width
and diameter of the drum employed in the said machine or the fibre.may be run
off in continuous lengths as hereinafter described and the thickness of the web is
regulated by the amount of cotton allowed to accumulate on the said drum, as is
well understood in the arts. The cotton deposited on the drum of the batting
machine is very loose and too tender to be handled in the manner of handling the
smaller and firmer rolls of batting produced for ordinary purposes, and cannot be
rolled upon itself and then unrolled without loss of evenness of thickness, the web
is therefore rolled from the drum of the batting machine on some other material,
that known as burlaps answering the purpose very well.
To accomplish this, a roller is provided in front of the batting machine and to
this roller is conducted one end of the burlaps employed, and on this burlaps, the
cotton fibre web from the machine is laid and by revolving the roller the web and
the burlaps are wound together on the said roller in such a manner as to have a
thickness of burlaps between each thickness of fibre, care being taken not to wind
the web on the roller too tightly, as by so doing it would retard the process to
which it is next subjected. The burlaps should be a little wider than the sheet of
fibre web and the roller, on which both are wound, should be longer than the width
of the burlaps.
Having wound a sufficient length of the web on the roller as described the roll
is next secured from unrolling by any convenient means, tying them with cords at,
say twelve inches apart, answers very well; but whatever means may be employed
for this purpose, care should be taken not to compress to the roll to such an extent
as to retard the next operation.
The roll is placed next in a bath of boiling water or a weak solution of such
chemical agent as shall act some desired part in the next operation as hereinafter⚫
explained When water alone is employed in this bath, the chief object is to
thoroughly saturate the fibre therewith and by doing so to displace and drive out
the atmospheric air and foreign matter, that is held in and between the said fibre;
for if such result be not accomplished by these or other means, it will be found
very difficult, if not impossible, to effect a complete combination of the fibre with
the gelatine which is subsequently applied.

page_text: .
The boiling should continue for one or more hours according to the thickness of
the fibre web and size of the roll under treatment, but having accomplished this
end the hot saturated roll is taken from the boiling bath and allowed to drain
until most of the water that will run off has done so.
The rolls are next placed in a bath of water gelatine and bichromate of potash
The proportions are not material but for general practical results this second bath
is compounded in the following proportions Water Six gallons, Gelatine eight
pounds, and bichromate of potash three per cent of the gelatine. The chromic salt
may be left out at this stage and applied afterwards or may be entirely substituted
in like manner other agents employed in the after part of the process may be
introduced at this stage with advantage according to the final effect or character of
the perfected material desired as hereafter described.
The object of using the bichromate of potash in connection with the gelatine is
to render the latter more or less insoluble when exposed to light as is understood
in photographic art or the same effect in connection with the chromic salt is
produced by elevation of temperature or at the ordinary temperature when sufficient
time is allowed which may be days weeks or months according to circumstances
Instead of having a separate vessel for the second bath the fluid of the first bath
could be drawn off and the same vessel used for the second bath but it is preferred
to proceed as described.
As to the character of the gelatine employed although that known in commerce
under the term glue answers the purpose well still it is well known in chemistry
that the strength and durability of the gelatine is greatly affected by high
temperature or by frequent dissolving. It is therefore preferred to obtain the
gelatine direct from any of its sources of production and while still in solution as
obtained in the ordinary method of its production to directly apply it to the
purposes of this process as setforth thus obtaining a stronger and more durable
final result.
Having compounded the second bath in about the proportions named there is
immersed in it at a temperature of 120° Fahrenheit more or less the roll containing
the fibre previously prepared as described and it is allowed to remain in the said
gelatine bath for a sufficient time say two or more hours, until the water or solution
with which the fibre has been previously saturated is completely replaced by the
gelatine compound. The roll is next removed from the gelatine bath and allowed
to drain until most of the surplus liquor runs off. The fibre held between the
burlaps is next placed on a slab or sheet of glass or other material upon which it
is unrolled so as to bring the gelatinized fibre next to the surface of the glass or
other material employed.
Sufficient pressure of any kind is now brought to bear on the burlaps to force
the gelatinous mass into as close contact as possible with the glass or other surface
on which it is spread the said contact being well effected by brushing or rolling.
The fibre and the gelatine are now in the condition of a sheet of pulpy jelly and if
the fibre has been thoroughly combined with the gelatine it is at this stage almost
indistinguishable therefron having been rendered more or less transparent by its
union with the said gelatine.
If a solid and compact leather be desired more of the gelatine compound is
poured over the burlaps or their equivalent and spread evenly thereon and it will
run through the said burlaps or other material and mingle with the gelatinous
mass spread beneath it increasing the proportion of gelatine therein contained.
The burlaps is now removed and the gelatinized fibre allowed to remain on the
glass or other material until dry which will require twelve or more hours
according to thickness of material temperature and ventilation with which it is
surrounded.
The semi-liquid and pulpy condition of the gelatinized fibre as it is placed on
the glass slab is such that it cannot be well brushed or rolled without disturbing
the uniformity of its arrangement and hence the necessity of using the sheet of

page_text: burlaps or other material as an intermediate means to allow of distributing the
gelatine compound poured on as described.
A further degree of solidity can be added to the material by again treating it
with the gelatine compound after drying and still further increased pressure As
a material on which to spread the gelatinous fibre glass or other more or less
translucent material is preferred so that light can penetrate through the said
material and produce on both the lower and the upper surface of the said gelatinous
fibre the effect of light due to the chemical properties of the chromic salt contained
in the gelatine rendering said gelatine insoluble It is necessary that the exposure
to light be continued after the material has become dry for it is while dry that the
insoluble effect is most readily and effectually produced the colour of the light
transmitted to the gelatinous fibre containing the chromic salt or its equivalent is
also important For instance if the color be blue the action will be slow if
yellow or ruby the said action will be almost entirely arrested A material void
of color is therefore most desirable through which to transmit the light for this
purpose white glass being the best The gelatinous fibre may be spread on some
other surface which need not be at all transparent, but in that event the material
should be exposed to light after removal therefrom but if the gelatinized fibre.be
spread on the glass as described and while thereon exposed to the action of light
that surface which is next to the glass becomes much more solid and compact in
its texture and when removed from the said glass as hereafter described presents
two surfaces distinctive in their character. The surface which was next the glass
is smooth and compact and not inclined to shrink when dampened and redried
while the other surface which formed the uppermost side of the gelatinous fibre as it
lay on the glass is even but not smooth and will contract when dampened and
redried. In these respects the material corresponds with the skin of an animal, the
smooth side representing the outer or grain side and the other side corresponding
with the flesh side of said skin.
In drying it will be found that the mass of gelatinous fibre has become more
transparent and very greatly lessened in thickness, the whole of its contraction
being in that direction thereby securing a greater amount of strength in proportion
to its thickness It is also very hard and adheres vory tenaciously to the surface
on which it was dried. To remove it however, it is only necessary to moisten the
material in any convenient way by immersion sprinkling washing or other moans
until softened through its entire thickness.
Now if the potash bichromate was admixed with the gelatine bath as described
then water will answer to soften and remove the artificial skin from the surface on
which it was dried or if a greater degree of insolubility be desirable this water may
contain alum or chrome-alum or any other agent capable of producing the desired
end and if the chromic salt or its equivalent was not admixed with the gelatino
compound comprising the second bath then this stage of the process affords a good
opportunity for its introduction.
A solution of said salt say one containing three per cent of bichromate is used
for softening the artificial skin as it lays on the surface on which it was dried.
When sufficiently moistened it is easily removed by rolling it up or in any other.
convenient way
If a solution of the chromic salt has been employed in the
removal the artificial skin is next dried in any way and exposed to light for a few
hours but if water has been the medium of removal the skin may be placed in the
third bath of tanning preparation hereinafter referred to although a greater degree.
of compactness is assured by drying it before its subjection to this final bath or if.
the gelatine contains or has been treated with the chrome salt or its equivalent.
and thus rendered insoluble and imputrescible, the leather at this juncture may be
completed by simply rendering it opaque and flexible Opacity may be imparted
by soaking in a solution of any carbonate (say carbonate of soda) or one of many
other methods may be employed For suppleness, glycerine may be added in the.
last mentioned treatment or at some other stage in the process.
. Instead of boiling the roll of fibre in water a solution may be employed such as.

page_text: that of alum, a salt of iron or any agent capable of rendering the gelatine
subsequently applied more insoluble or to facilitate the displacement of the air and
other contents of the fibre under treatment, or the first bath may possibly be
substituted by placing the fibre in an air tight vessel and exhausting the air
therefrom by means of a vacuum and the second bath compound applied to the
fibre while in said vacuum. Or the gelatine compound may be directly applied to
the loose fibre and forced into and between it by pressure or any other means may
be employed The method described of successive baths produces a uniform and
reliable result the fibre becoming indistinguishable from the gelatine the whole
forming a transparent sheet of perfectly gelatinized fibre one homogeneous substance
such as is very difficult if not impossible to produce by other means although the
product by the other methods described may suit well for some purposes.
Now I have described the preparation of the artificial skin which forms the basis
of the new kind of leather and this material has so close a resemblance to a natural
skin that it may be finished by any of the methods employed for treating skins of
animals to produce leather or the said treatment requiring but slight modification.
If it be determined to finish the leather in the ordinary way of tanning it will
be found that it has the very great advantage of not being affected by elevation of
temperature as the natural skin is hence the tanning solutions wherewith it is
treated may be employed at a high heat and thus effect in a few hours what
would otherwise require days. If however a more porous or spongy leather be
required it is preferred to allow more time at a lower temperature.
The tanning preparation for the final treatment or tanning is preferred to be
composed of water containing equivalent to say five per cent of tannic acid and
twenty five per Cent of glycerine or other agent capable of imparting flexibility
The tannic acid may be added as such or bark or sumack nutgalls or any other
compound or material containing tannic acid or its equivalent may be employed
instead thereof.
But the Invention is not limited to the use of tannic acid since any ingredient
agent method or methods known to produce the effect designated and understood
under the general terms of tanning and tawing may be employed instead.
Owing to the aforementioned peculiarity of the contractibility of one side of the
artificial skin and the incontractibility of the side next to the surface on which it
was dried this leather may be grained in like manner to a natural skin so that
when the said material is rolled and rubbed as is understood in the method of
graining the one side contracts and the other side wrinkles to accommodate the
said contraction; the form of said wrinkles being governed by the direction in
which the skin is rolled and manipulated according to the skill of the Operator
The peculiarity of these wrinkles constitutes the different styles of graining as
understood in the arts.
Many modifications of the process may be made with desirable results according
to the effect aimed at; For instance when the gelatinous fibre is placed on the
surface on which it is intended to be dried no additional gelatine solution may be
added as setforth in such event the artificial skin when dry will be less solid inore
spongy and soft.
If a finished leather be desired of such thinness as is impracticable to be formed
out of so frail and tender a web as that formed by the fibre employed the following
plan can be made available. Proceed as already set forth with the production
of the sheet of gelatinous fibre and place it on the glass or other material as
described next lay on it the sheet of burlaps or other material and upon this bring
to bear any convenient pressure such as that of a roller which treatment tends to
concentrate the amount of fibre in the body of the artificial skin and forces a
larger proportion of gelatine to the two surfaces. Next dry the skin as usual and
when dry remove in the manner setforth and while still wet it will with care
evenly split the concentration of the gelatine on the surfaces strengthening them
causing the material to separate in the middle where it is weakest. Having thus
secured as thin, a skin as desired it can be tanned tawed or finished by any method in

page_text: this condition or additional gelatine compound may be applied to the split side
according to the style of leather required.
Any thickness of leather or artificial skin can be secured by regulating the
thickness of the fibre first employed or by uniting two or more thicknesses of the
material at any stage of the process most convenient.
The character of the leather may also be varied by removing the gelatinous fibre
from the surface upon which it is spread before it has become dry and completing
the drying without contact with any surface or it might be dried direct from the
roll without having been spread on any surface in either case the dried artificial
skin will not have a smooth or grained side but will have two porous or flesh sides
which can be made smoother by coating with the gelatine compound used in the
second bath but it will be readily understood that the surface thus applied is not
homogeneous with the body of the leather but will be of the nature of a similar
application made to other material. If the gelatine compound thus applied to the
surface be colored and the material while still damp be brought into close contact
with a glossy surface and allowed to dry thereon the surface of the finished leather
will resemble the ordinary patent or enamelled leather.
One feature of the improved leather which it possesses in common with leather
made from animals skins and which recommends it for many applications in the
arts is its elasticity when stretched in any direction especially while damp. This
quality is due to the homogeneous combination of unbroken separate fibres with
gelatine which quality could not be had with a broken fibre as in paper or the
pulp whereof it is made or with a woven or spun fabric where the warp or woof
would be opposed to such elasticity.
It will be understood that by the terin " homogeneous compound of fibre and
gelatine" is not meant that the former is dissolved so that its identity is entirely
lost as fibre since if this were the case the resulting product would not be true
leather in which the fibre fibrine or tissue although being one substance intimately
but mechanically mixed with the gelatine possesses its individual existence and
imparts the structural characteristics as fibre to the finished article.
The leather made by this Invention is like the true leather made from natural
skins in that it contains numerous ramifying fibres intersecting one another in
every position and in this it is different from the so called artificial leather which
has been heretofore made by coating woven fabrics with gelatine Such artificial
leather does not possess as does the improved product the properties of real leather
namely intimate and homogeneous mixture of the fibre and gelatine capability of
stretching equally in every direction of being split and of having its edges
" skivered."
Having now described and particularly ascertained the nature of the said
Invention and the manner in which the same is or may be used or carried into
effect I would observe in conclusion that what I consider to be novel and original
and therefore claim as the Invention secured to me by the hereinbefore in part
recited Letters Patent is :-
First In the manufacture of leather the method of forming an homogeneous
mixture of fibre and gelatine by displacing the air and other foreign substances
from the said fibre and applying thereto the gelatine or a compound thereof in
substantially the manner herein before described.
Second: In the manufacture of leather the method of producing an artificial
skin or web by boiling cotton or other fibre in water or a suitable solution as herein-
before described and applying to the said fibre glatine or a compound thereof
substantially as herein before described.
Third In the manufacture of leather the method of forming an artificial skin or
web by boiling cotton or other fibre in water applying gelatine thereto treating
the said fibre with bichromate of potash or its equivalent and exposing to light
substantially as hereinbefore described.
Fourth-The method of forming an homogeneous and insoluble compound of fibre
and gelatine consisting in displacing the air and other foreign substances from the

page_text: said fibre applying gelatine thereto treating with bichromate of potash or its
equivalent and exposing to light substantially as herein before described.
Fifth The method of producing an artificial skin or web by boiling cotton or
other fibre in water or a solution then treating the said fibre in a bath of water
gelatine and bichromate of potash in approximately the proportion specified drying
the fibre and gelatine thus formed on a smooth slab or surface and exposing to the
action of light substantially as hereinbefore described.
Sixth The method of producing an artificial skin or web by forming an homo-
geneous compound of fibre and gelatine in the manner herein before described and
spreading the said compound to dry upon a sheet of glass or other translucent
substance substantially as herein before described.
Seventh In the manufacture of leather the method of producing an artificial
skin or web by treating fibre while in a roll between burlaps or other material in
a bath of boiling water or solution and in a second bath of gelatine compound then
unrolling the glatinized fibre thus formed upon a sheet of glass or similar material
and allowing it to wholly or partly dry thereon substantially as hereinbefore
described.
Eighth-The improvement in the art of manufacturing leather consisting in
treating fibre in a roll between other material with a gelatine compound spreading
the gelatinized compound upon a suitable surface as hereinbefore explained and
applying additional gelatine thereto substantially as and for the purpose herein-
before described.
Ninth The improvement in the art of manufacturing leather consisting in
forming an homogeneous mixture of fibre and gelatine spreading the same upon a
suitable surface and subjecting it to pressure thereon so that the artificial skin or
web when moistened and removed can be readily and evenly split substantially as
herein before described.
Tenth The improvement in the art of manufacturing leather consisting in
forming a sheet or web of fibre and gelatine as explained exposing the same to
dry upon a sheet of glass or other substance allowing it to wholly or partly dry
thereon and removing by the application of moisture substantially as herein before
described.
Eleventh-The method of producing a colored or enamelled surface upon a sheet
of gelatinized fibre such as hereinbefore described by applying colored gelatine
thereto and drying in close contact with a smooth surface substantially as herein-
before described.
Twelfth In the manufacture of an artificial skin for the production of leather
the method of treating fibre to exclude the air and other foreign substances there-
from by immersing it in a bath of boiling water or solution substantially as
herein before described.
Thirteenth Leather composed of a homogeneous compound of fibre and gelatine
substantially as herein before described.
Fourteenth Leather composed of a mixture of fibre and gelatine and rendered
insoluble by treating with chromic salt and exposure to light substantially as
hereinbefore described
Fifteenth Leather formed of fibre and gelatine and having an enamelled surface
substantially as herein before described.
Sixteenth-Leather composed of a homogeneous mixture of fibre and gelatine
and having two distinctive surfaces corresponding respectively to the flesh and
grained sides of leather made from the natural skins of animals.
Seventeenth The process substantially as hereinbefore described of making
leather by homogeneously combining gelatine and fibre to form artificial skin and
then tanning the same.
Eighteenth Leather composed of gelatine and fibre homogeneously combined so
as to form an artificial skin and subjected to the process of tanning substantially
as herein before described,
Nineteenth-The process substantially as herein before described of making leather

page_text: by homogeneously combining gelatine and fibre to form an artificial skin and then
tawing the same..
Twentieth-Leather composed of gelatine and fibre homogeneously combined so
as to form an artificial skin and subjected to the process of tawing substantially as
hereinbefore described.
Twenty-first. The process of forming an artificial skin by homogeneously
combining fibre and gelatine substantially as herein before described.
Twenty-second-Artificial skin formed by homogeneously combining gelatine
and fibre substantially as hereinbefore described.
Twenty-third. The process of making leather substantially as hereinbefore
described by combining gelatine and fibre to form an artificial skin the same being
acted on by chromic acid or its compounds.
Twenty-fourth-Leather composed of gelatine and fibre homogeneously combined
so as to form an artificial skin and acted upon by chromic acid or its compounds
substantially as herein before described.
Twenty-fifth-The process of making leather substantially as described by
homogeneously combining gelatine and fibre to form an artificial skin the same
being acted upon by chromic acid or its compounds and then tanned or tawed.
Twenty-sixth. Leather composed of gelatine and fibre homogeneously combined
so as to form an artificial skin and acted upon by chromic acid or its compounds
and then tanned substantially as hereinbefore described.
Twenty-seventh-Leather composed of gelatine and fibre homogeneously combined
so as to form an artificial skin and acted upon by chromic acid or its compounds
and then tawed substantially as herein before described.
In witness whereof I the said John Henry Johnson have to this my
Specification set my hand and seal the eighth day of February One
thousand eight hundred and eighty three.
TTR DY
TRADH
KERRI
JOHNSON (L.S.)