Improvements in the Utilization of Leather Waste.
Year: 1888

page_text: Date of Aplication, 3rd Oct., 1888
Complete Specification Left, 3rd July, 1889-Accepted, 3rd Aug., 1889
PROVISIONAL SPECIFICATION.
Improvements in the Utilization of Leather Waste.
1, WILLIAM AUGUSTUS BURROWS, of Berkeley Street, Piccadilly, Manufacturer, do
hereby declare the nature of this invention to be as follows:-
My present invention relates to improvements in the method of treating and
utilizing the waste parts of leather, and it has reference more particularly to
improvements on the invention for which Letters Patent were granted to James Wass™.
Davies for "The Industrial utilization of Leather waste dated 6th day of October
1885, and numbered 11,880.
י,
By my present invention I take waste pieces or scraps of leather, and I preferably
reduce them by means of any suitable form of disintegrating machinery to the form
of fine shreds or flock. I then submit this leather flock or parings or pieces of leather
which have not been treated in disintegrating machinery as described, to the action of
a suitable acid such as oxalic, citric, tartaric, acetic acid, or of an alkali-such as soda,
potash, or ammonia, or their salts, and in this way a chemical change is effected in
the leather by which it is made more suitable for the articles into which it is to be
subsequently manufactured as hereinafter described, more especially as respects
hardness, flexibility, and resistance to damp, heat, and acid. When the leather flock
has been thus sufficiently treated, I mix it with a sufficient quantity of such fibrous
materials as spent tan, bark, wood-pulp, jute, oakum, manilla, hair, Rhea, fibre, old
rope, tow, asbestos, or other suitable fibrous materials, the quantity and proportions
of which may vary according to the purpose for which the leather is ultimately
to be used.
·
To the mixture I add one or more suitable gums, lacs, or resins, or vegetable
products, such for instance as caoutchouc, residues from the boiling of linseed or other
oils, or bituminous materials previously dissolved or otherwise treated by any of the
ordinary well known processes, or oils, waxes, vegetable or animal gelatine, or any
combination of two or more such substances or substances of the like kind.
The mixture of the leather flock with such substances having been thoroughly
effected, it may be rolled into sheets or forced into moulds by sufficient pressure,
either with or without heat, for the purpose of utilizing it as hereinafter described, or
may be vulcanized in the ordinary well known way, and colouring or other materials
may be first added to it in order to improve its appearance and render it more suitable
for the different purposes for which it is to be employed.
it
Sometimes, instead of treating the leather flock in the manner described, I take it
as it comes from the disintegrating machine, and I use it either alone, or with a
mixture of other suitable fibrous material, for the manufacture of a pulp from which
I make paper, cardboard, or other articles of the like kind, in the usual way practised
by paper makers.
Or, sometimes I use the leather flock as an absorbent material and I mix it with a
solution of gelatine or gelatinous matter, which may preferably be treated with a
proper proportion of alum, aluminous salts, or salts of tungsten, chrome, copper, zinc,
manganese, or iron, or of borax or silicates, by which the compound is rendered
harder, more durable, and less absorbent of moisture, and in some cases a small
proportion of organic or mineral acid may be used.
Instead of the acids or alkalis first described, the leather flock may be submitted to
the action of superheated steam, or suitable vapour, or oil.
I do not confine myself to the precise ingredients, some of which I have mentioned,
which may be varied more or less in character, number, and proportion, as may be
found advisable.
The compound, prepared, and treated as described, is cheap, and easily made, and it

page_text: may be used for a very great number of purposes. For instance, it may be used as
an electrical insulating medium, for covering conducting wires, and for making
insulators, for belting for machinery, and for the heels or soles of boots and shoes.
Dated this. 3rd day of October 1888.
EDWARDS & Co.,
35, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Utilization of Leather Waste.
I, WILLIAM AUGUSTUS BURROWs, of Berkeley Street, Piccadilly, Manufacturer,
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 following.
statement, that is to say :-
My present invention relates to improvements in treating leather waste and in
combining it with other materials, so that it can be utilized in the manufacture of soles
and heels for boots and shoes, for insulating electrical conducting wires, and making
electrical insulators, for friction blocks for brakes, for moulding into various forms
such as door handles or knobs and for other purposes of the like and analogous
kinds.
It relates more especially to improvements in the method of treating and utilizing
the waste parts of leather, and it has reference more particularly to improvements
on the invention for whicli Letters Patent were granted to James Wass Davies for
"The Industrial utilization of Leather Waste" dated October 6th A.D. 1885, and
numbered' 11,880.
I take waste pieces or scraps of leather, and I preferably reduce them by
means of any suitable form of disintegrating machinery to the form of fine shreds
or flock.
Where this flock is to be used for the manufacture of hard articles, such for instance
as the heels of boots or shoes, electrical insulators and the like, 1 use the leather
flock as an absorbent material and. I mix it with a solution of gelatine or gelatinous
or glutenous matter to which has been preferably added a proper proportion of alum,
aluminous salts, or salts of tungsten, chrome, copper, zinc, lime, manganese, or iron,
or of borax or silicates, by which the compound is rendered harder, more durable,
and less absorbent of moisture; and in some cases a small proportion of organic or
mineral acid may be added.
The proportions of the different materials will necessarily vary according to the
particular ones which are used, and the purpose to which the finished articles are to
be applied. The following give good results. A sufficient quantity of the leather
flock. mixed with a solution of gelatine to which has been added not more than
one-tenth per cent. of chrome alum. The mixture whilst in a damp state may be
moulded or otherwise formed into any desired shape, and when dry is perfectly hard
and durable.
If instead of chrome-alum, a silicate such as silicate of soda is. used,. I take, a
gelatinous solution containing (as before) about. 1 pound of gelatine in 12 pounds of
water, silicate of soda 6 ounces, and leather flock 18 pounds; to which may be added
a small quantity say 6 ounces, (which may be varied more or less) of ordinary
acetic acid.
This mixture is treated and manufactured in the same way as that first described'..
If, instead of silicate of soda, borax is used, the acid.need not be added.
If the other materials mentioned above are used, a suitable proportion (which
depends not only upon the particular material used, but upon the purpose to which
the product is to be applied, but which will not vary materially from the proportion
mentioned of silicate of soda) of the material selected is mixed with the solution of
gelatine and the leather flock, and the mixture is moulded or otherwise manufactured
into the required articles as already described.

page_text: I submit the disintegrated leather flock to the action of a suitable acid, such as
oxalic, citric, tartaric, or acetic, or of an alkali such as soda, potash, or ammonia, or
their salts, and in this way a chemical change is effected in the particles of the leather
by which they become more suitable for articles into which it is to be subsequently
manufactured, when hardness, and resistance to damp, heat, and acids, with a sufficient
amount of flexibility are required.
For instance if oxalic acid is used, I boil the flock for a short time (say about
five minutes) in a bath consisting of about 1 ounce of oxalic acid to every five pounds
of water. If other acids are used, such as tartaric, citric, or acetic, 1 preferably
If instead of
ase a somewhat larger proportion, say about one and a half ounces.
acids, an alkali, or alkali salt is used, the bath is used cold, and consists of a solution
of about one ounce of the alkali or salt to every two pounds of water.
-
When the leather flock has been thus sufficiently treated, I wash it until all traces
of the acid or alkali are removed, and I then mix it with a sufficient quantity of
fibrous material such as spent tan, bark, wood pulp, jute, oakum, manilla, hair, Rhoa
fibre, old rope, tow, asbestos, or the like, the quantity and proportions of which may
be varied according to the purpose for which the finished material is to be used.
For instance the proportion of such fibrous material used may be from 20 to
50 per cent. Or, sometimes, 1 mix such fibrous material with the leather flock
previous to its treatment with acid.
To the mixture I add one or more suitable gums, lacs, resins, or vegetable products
such for instance as caoutchouc, the residues from the boiling of linseed or other oils,
or bituminous materials previously dissolved or otherwise treated by any of the
ordinary well-known processes, or oils, waxes, vegetable or animal gelatine, or any
combination of two or more such substances or substances of the like kind.
For instance 1 make a solution consisting of about 7 to 15 per cent. of such gum,
resin, or other material (which gum, resin, or other material may in some cases be
first vulcanized) in linseed or mineral or other suitable oil, and I add about 1 pound
of such solution to every 10 pounds of the mixture of prepared flock and fibre.
The mixture having been thoroughly effected, the product may be rolled into sheets
or forced into moulds by sufficient pressure by any of the ordinary well-known forms
of presses or machinery, with or without heat, in order to utilize it for the purposes
required, and colouring or other materials may be first added to the mixture in order
to improve its appearance and render it more suitable for the different purposes for
which it is to be employed.
Sometimes, instead of treating the leather flock in the manner described, I take it
as it comes from the disintegrating machine, and I use it either alone, or with the
addition of other suitable fibrous material as already described, for the manufacture
of a pulp from which I make paper, board, or other articles of the like kind in the
usual way practised by paper makers. The products so obtained may then be dried
sufficiently to allow their surface to absorb a sufficient quantity of the solutions of
gums, resins, or other like materials already described.
Where the leather flock is to be used as an insulating material for purposes such
I take of
as covering electrical conducting wires I use it in the following manner.
gum copal about two parts by weight, Stockholm tar one part, Almadina gum
three parts, leather flock, after treatment with acid or alkali as described, one and
a half parts, oil (such as linseed oil) one and a half parts, and leather flock
(disintegrated but not otherwise treated) three to five parts.
This last mentioned leather flock is preferably used to coat the conducting wire
after the latter has been first covered with a sufficient thickness of a mixture of the
other materials.
The coating prepared as described is cheap and an excellent non-conductor, and
is sufficiently flexible, very durable, and not liable to lose its properties.
Instead of treatment by acids or alkalis in the manner described, I sometimes
submit the leather flock to the action of steam which may be superheated and with
which may be mixed ammonia or chlorine gas:

page_text: I do not confine myself to the precise ingredients, acids, alkalis, gums, resins, and
so on, some of which I have mentioned, since it is evident that other ingredients of
the like kind, or possessing the same properties, may be substituted for them to a
greater or less extent; and the proportions of the different ingredients used may
also be varied more or less as may be found advisable according to the different
purposes to which the invention is to be applied.
The improved material may be used for an infinite number of purposes.
For instance, the hard material may be used not only for the heels of boots and
shoes, and for the handles and knobs of doors, but as a substitute for wood, glass,
metal, and china, for very many purposes to which these materials are ordinarily
applied, whilst the softer and more flexible material may be used not only for the
soles of boots and shoes, and for electrical insulating purposes, but for driving belts
and for a great number of purposes for which leather is ordinarily used.
I am aware that it has been proposed to use leather waste reduced to fragments
for various purposes, and I do not claim generally such use of leather waste, but
having now particularly described and ascertained the nature of my said Inven-
tion, and in what manner the same is to be perforuied, I declare that what I
claim is:-
1. The method of treating leather flock, for the purpose of manufacturing hard
articles, by mixing it with a gelatinous solution containing chrome-alum or other
substances rendering gelatine non-absorbent of water, with or without the addition of
organic or mineral acid, substantially as set forth.
2. The method of treating leather flock with acid, such as oxalic, citric, tartaric,
or acetic, or with alkali, such as soda, potash, or ammonia, or their salts, of washing
out all.trace of acid or alkali, of adding fibrous material to the prepared flock, and
of adding to the mixture one or more gums, lacs, resins, or vegetable or other
products, so as to produce a material which can be rolled into sheets or pressed into
moulds, substantially as set forth.
3. The method of treating leather flock by making it into a pulp, either alone or
mixed with other fibrous material, such pulp being made into paper or board of any
thickness, and then when sufficiently dry saturated with a solution of gum, resin, or
other like material, substantially as set forth.
4. The method of utilizing leather flock in combination with the other materials
substantially as set forth, as an electrical insulating material.
5. The method of treating leather flock by submitting it to the action of steam,
superheated, or mixed with ammonia or chlorine gas substantially as set forth.
Dated this 2nd do XY TA
EDWARDS & Co.,
35, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Inventor.