Treatment of Waste Substances for the Production of Leather Board and Material suitable for being Pressed into Form for Decorative and other Purposes, or for Use in Substitution for Leather, Floor-cloth, and the like.
Year: 1896

page_text: Date of Application, 13th June, 1896
Complete Specification Left, 13th Apr., 1897--Accepted, 12th June, 1897
PROVISIONAL SPECIFICATION.
Treatment of Waste Substances for the Production of Leather Board
and Material suitable for being Pressed into Form for Decorative
and other Purposes, or for Use in Substitution for Leather,
Floor-cloth, and the like.
I, THOMAS HENRY COBLEY, of Albion Street, Dunstable, in the County of
Bedford, Manufacturing Chemist, do hereby declare the nature of this invention
to be as follows:-
My invention relates to the treatment of waste fibrous and animal substances for
the production of leather board and material suitable for being pressed into form
for decorative and other purposes or for use in substitution for leather, floor-cloth
and the like.
For this purpose I pulp or beat, while boiling, waste fibrous material, such as
raw cotton waste, droppings, shoddy and the wax, oil, albuminous and extractive
matter derived from cotton seed and shell, with an alkaline compound such as
silicate or sulphite of soda or other available alkaline combination, and, by addition
of lime or the like, I precipitate on the fibrous material, the oily, albuminous or
other extractive matters present and then drain off the alkaline liquor. I separately
treat waste leather or other animal substance with sulphurous acid or other reagent
to set free its gelatinous ingredients, and add this to the pulp, thoroughly
incorporating the whole, and adding a tanning agent or chromium compound to
precipitate or fix the gelatinous matter on the cellulose of the fibrous matter in
the form of leather.
The mass is then made into boards by hand or machine or rolled, pressed or
moulded into such forms as may be desired.
The alkaline liquor drained from the pulp may be boiled with silica so as to
produce silicate or may have fumes of burning sulphur passed through it to produce
sulphite, for use on fresh quantities of raw material.
Dated this 13th day of June 1896.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Treatment of Waste Substances for the Production of Leather Board
and Material suitable for being Pressed into Form for Decorative
and other Purposes, or for Use in Substitution for Leather,
Floor-cloth, and the like.
I, THOMAS HENRY COBLEY, of Albion Street, Dunstable, in the County of
Bedford, Manufacturing Chemist, 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:-
My invention relates to the treatment of waste fibrous and animal substances for

page_text: the production of leather board and material suitable for being pressed into form
for decorative and other purposes, for making floor-cloth and for use in substitution
for leather in trunk making and the like.
For this purpose, I take, for ordinary qualities of product, waste fibrous material
such as raw cotton waste, droppings and cotton shoddy containing still a quantity
of seed and shell and boil the whole with an alkaline compound such as silicate,
sulphite, sulphate, carbonate or subcarbonate of soda equal in weight to about
10 per cent. of the waste.
The boiling should be carried out in an apparatus where it can be beaten and
boiled simultaneously, such as the washing or beating engine of the paper maker;
or the fibrous matter can be first boiled and then washed and beaten.
Where it is desirable to convert the whole mass into available material, then, in
the case of raw cotton waste, the alkaline reagent most to be preferred is a
subcarbonate or a mixture of carbonate and caustic soda known as caustic soda
ash. When properly conducted, about 4 hours will be sufficient for this
operation.
Milk of lime is then introduced until the decomposed seed and shell are
precipitated upon the fibrous matter and the whole is then beaten up with the
leather preparation hereinafter described. For better qualities of material, the
seed and shell accompanying the fibrous matter are eliminated by washing,
bleaching or half bleaching in the ordinary manner, or any manner is employed
where colour is an object, and the mass is then beaten up into pulp with the
leather preparation and other ingredients, as required for manufacturing the
various products.
The mixed pulpy mass prepared as above described is made into boards by hand
or machine, or rolled, pressed or moulded into such forms as may be desired.
I do not confine myself exclusively to the use of raw cotton, as other waste
vegetable fibrous matters may be employed in addition, when advantageous.
will in the first
As the treatment of leather waste and animal refuse for the production of the
leather preparation forms a very important part of my process,
place explain the treatment of leather waste.
There are several kinds of leather waste, namely upper and sole leather shavings,
which are principally tanned leather, and fancy leather clippings which are mostly
tawed or alum-prepared leather; and, besides these, animal waste the principal
source of which is hide cuttings or fleshings and the used brine or pickle from
salting or curing houses.
With waste leather the various sorts have to be separated, the tanned from the
tawed, and the clean from the greasy.
The tanned upper leather waste is boiled for several hours at a low temperature
in the presence of sulphurous acid equivalent to 5 to 10 per cent. of the mass under
treatment, it is then allowed to cool, the fat is removed and the acid is neutralised
by means of soda or lime and the mass is then disintegrated by continued boiling,
after which a mixture of lime and alum is added producing a precipitate. This
precipitate, consisting of a double tannate of calcium and aluminium, is employed
to mix, as stated above, with the prepared fibre to form a compound for the
manufacture of leather board and the like.
Sole leather waste is best treated with soda solution such as subcarbonate, caustic
soda ash, sulphite or silicate or other salt of soda, but preferably with caustic soda
ash in proportion of from 5 to 10 per cent. of weight of material under treatment.
This mixture of waste and soda solution is heated to a somewhat lower temperature
than boiling until the leather is broken up and nothing remains but the fibrin; the
tannate is then precipitated by the combined action of lime and alumina, the
precipitate is collected and beaten up with the fibrous matter as before described.
Instead of precipitation with lime and alumina, the solution may be boiled with
tawed leather waste which containing an alumina compound will serve to
precipitate the alkaline solution of leather if employed in sufficient quantity to
neutralise the alkali used.

page_text: In the treatment of animal waste for producing an artificial or synthetic leather
precipitate, it is not necessary to employ the preliminary treatment with sulphurous
acid or other reagent but, where waste brine or pickle containing animal matter
can be had in quantity, then tannin extract or a substance containing tannin is
added to the same in proper proportion, that is until precipitation ceases. The
brine is then boiled to render the precipitate more dense and easily collected. In
the preparation of the leather precipitate from hide cuttings and fleshings, these
are boiled with tannin extract for some hours when the gelatine contained in the
cuttings or fleshings will become converted into artificial or synthetic leather in
the state of fine curds and irregular particles ready for mixing with the prepared
fibrous material to be made up into boards &c., or as a base for forming composite
bodies for other purposes.
As the hide cuttings and fleshings may contain an appreciable quantity of fat,
the liquor is allowed to cool and the fat is carefully removed, as it would be very
detrimental in the further working of the pulp.
The proportion of leather precipitate to fibrous matter may vary from 20 to
40 per cent.
The combination of the fibrous material and leather precipitate may be worked
up into leather boards, plain, waterproofed or waxed, embossed boards for panelling,
floor cloth, and as a substitute for leather generally.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The herein described processes for the production of a combination of raw
cotton fibre or waste with precipitated leather.
2. The herein described manufacture of leather boards and material suitable
for being pressed and moulded into form.
Dated this 13th day of Anil 1907
ABEL & IMRAY,
Agents for the Applicant.