An Improved Process for Mercerising Cotton Yarns and Fabrics.
Year: 1898

page_text: Date of Application, 6th June, 1898-Accepted, 17th Sept., 1898
COMPLETE SPECIFICATION.
An Improved Process for Mercerising Cotton Yarns and Fabrics.
I, LLONARD SCHADE VAN WESTRUM, of Magdeburg, in the Empire of Germany,
Merchant, do hereby declate 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:
-
This invention relates to a process of mercerising cotton in such a manner, that
the cotton-hbie, while attaming a high lustie or gloss, loses little or none of its
natural strength, a result which cannot be attained by the processes in vogue.
The old process consists in subjecting the cotton, in a strongly stretched state,
to the action of alkaline lye, and then neutralising it with liquid acid, a, for
example, acetic acid.
Now my process consists in subjecting the cotton, while in a state of slight ten-
81on, to the action of the alkaline lye, and then neutralising it with a gaseous acid.
I proceed as follows,-
-
The cotton yarn or fabric, in a well moistened or wet state, is attached to a
frame or the like, but without straining or applying tension thereto, and then
subjected to the action of a strong alkaline bath (not less than 32º Baumé)—
during some minutes, (say, from 6 to 10 minutes). The lye is then run off, and
the yain or fabric thus treated is transferred, on the frame, to a chamber into which
gaseous acid, preferably cabonic acid gas is flowing The approximate time
equned for this treatment with carbonic acid is from 10 to 20 minutes, accord-
ing to the quantity of carbonic acid gas contained in the chamber. This gas
penetrates the yarn on fabric, and converts the alkaline lye-(whether of potash
or soda) adheimg externally to the yarn or fabric, into a salt, which remains
on the yarn or fabric in the form of a crust As soon as the formation of salt,
and consequently the neutralisation, is effected, the chamber is heated by means of
a steam heating coil or the like, in order to dry the yarn or fabric. After the
drying, the yarn or fabric is taken to a washing machine, and rinsed therein with
clear water. The yarn or fabric thus treated is dried again, and is finished by
calendering, together with the other usual well-known operations, to fit the same
for the market.
As contrasted with the old process of mercerising, the herein-described process
presents the following advantages.
-
The yarn or fabric does not need to be subjected to severe strain before it is
presented to the action of the lye.
After having neutralized, by carbonic acid gas or its equivalent, the lye taken
up by the yarn or fabric, frequent insing is not needed, as is absolutely necessary
after the treatment with liquid acid, and much time is therefore saved.
The strength of the fibres is little affected, as the gaseous acid is less injurious
than liquid acid.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:-
A process of meicensing cotton yains and fabrics, consisting in subjecting the
same, in a state of slight tension, to the action of alkaline lye, and then neutral-
ing the lye by means of gaseous acid, substantially as and for the purpose
described