AN IMPROVED MANUFACTURE OF IMPERMEABLE LEATHER
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents on the 11th June 1879. A communication
from abroad by Frédéric Jayet, of Mines (Gard), France, Mechanician.
WILLIAM ROBERT LAKE, of the Firm of Haseltine, Lake, & Co., Patent Agents,
Southampton Buildings, London. "AN IMPROVED MANUFACTURE OF IMPERMEABLE
LEATHER." [A communication from abroad by Frédéric Jayet, of Mines (Gard),
France, Mechanician.]
This Invention relates to an improved manufacture of impermeable leather, and
comprises a process for utilizing waste pieces, scraps, scrapings and parings of leather,
hides, and skins, such pieces, scraps, and the like being commonly called parings
(bourriers), by which process the latter are so amalgamated as to form leather
similar to new leather, and having moreover the quality of impermeability.
In carrying the said Invention into practice I amalgamate or aggregate the said
scraps or parings by means of powerful pressure, after having agglomerated them
with albuminous matters contained in sheeps', bullocks', or calves' blood, and to
which has been added a certain quantity of lime.
The said scraps or parings are generally in a greasy condition, which would prevent
their being caused to adhere together by the blood, and it is therefore necessary to
commence by removing the grease. For this purpose I plunge the scraps or parings
into a weak solution of sulphuric acid composed of, say, about one litre of acid to
fifty litres of water. After having left the said scraps or parings immersed in this
solution for three hours, I remove and wash them in water. then dry them either
in the open air or by means of a drying stove, after having expelled the excess of
water by pressure, or by means of a hydro-extractor if necessary. The scraps or
parings having been thus deprived of the layer of greasy matter, I proceed to
agglomerate them, employing blood as the agglutinant, as herein before mentioned,
preferring for this purpose fresh sheeps' blood. The blood is enclosed within a tub,
or vat, or other suitable vessel, and one kilogramme of lime is added for every
hundred kilogrammes of blood. I employ for this purpose lime which has been
slaked or hydrated, and afterwards sifted to a sufficiently fine powder. Into this
bath of blood with lime I throw sufficient of the pieces, scraps, or parings of leather
or skin to form a gelatinous substance or magma, which is worked or stirred with a
stirrer by hand, or a pug-mill may be used. The albumen in the blood coagulates
in presence of the scraps and parings, and penetrates into their pores, and the pores

page_text: being thus filled the leather is rendered impermeable, and moreover the blood and
lime form a glue or compound which firmly unites the pieces together.
The paste or magma produced as above described is sufficiently plastic to be
moulded, and therefore the articles which it is desired to form thereof can be
produced in a direct manner, whatever may be the form or shape required.
I am thus enabled to mould heels for boots and shoes in one single piece, also
inner soles or welts and inside heel pieces. The operation for producing such articles
is effected in moulds of cast iron, provided with a movable counterpart for exerting
a powerful pressure upon the mass to be moulded.