An Improved Process for Printing Indigo on Fabric and Yarn.
Year: 1894

page_text: Date of Application, 10th Apr., 1894
Complete Specification Left, 9th Jan., 1895-Accepted, Sth Feb.,
1895
PROVISIONAL SPECIFICATION.
An Improved Process for Printing Indigo on Fabric and Yarn.
We, ANDRÉ BLANCHON and AUGUSTIN ALLEGRET, both of 95 Boulevard
Beaumarchais, Paris, in the Republic of France, do hereby declare the nature of
this invention to be as follows:-
:-
Our invention relates to a process for printing refined or crude indigo on any
fabric, such as silk, wool, cotton or the like, or on reserve yarn.
In lieu of employing reduced indigo for the impression, as has heretofore been
the case, we start from insoluble refiued or crude indigo by employing as inspissating
agents likewise insoluble products, especially white starch or algesine. The indigo
is then reduced upon the fabric or yarn itself by means of a reducing bath, and is
finally re-oxidized.
We operate in the following manner: The refined or crude indigo in the form
of powder is soaked with a mixture of water and white starch previously boiled to
a suitable consistency. The quantity of soaked indigo depends on the tint to be
obtained.
We print by the ordinary processes, and then pass the fabric or yarn into a
reducing bath, for example of hydrosulphite of lime prepared by the known
processes and the concentration of which we vary according to the richness of the
tints to be obtained and the nature of the fabric or yarn. This bath is kept
lukewarm till the indigo deposited has been completely reduced.
Next we take off the green colour by exposure to the air or otherwise, and
remove the inspissating agent and continue by the operations as heretofore
performed.
Dated this 10th day of April 1894
P
An Improved Process for Printing Indigo on Fabric and Yarn.
We, ANDRÉ BLANCHON and AUGUSTIN ALLEGRET, both of 95 Boulevard
Beaumarchais, Paris, in the Republic of France, 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 :-
Our invention relates to a process for printing refined or crude indigo on any
fabric, such as silk, wool, cotton or the like, or on reserve yarn.
In lieu of employing reduced indigo for the impression, as has heretofore been
the case, we start from insoluble refined or crude indigo by employing as inspissating
agents likewise insoluble products, especially white starch or algesine. The indigo
is then reduced upon the fabric or yarn itself by means of a reducing bath, and is
finally re-oxidized.
We operate in the following manner: The refined or crude indigo in the form of
powder is soaked with a mixture of water and white starch previously boiled to a
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page_text: suitable consistency. The quantity of soaked indigo depends on the tint to be
obtained.
We priut by the ordinary process, and then pass the fabric or yarn into a
reducing bath, for example of hydrosulphite of lime prepared by the known
processes and the concentration of which we vary according to the richness of the
tints to be obtained and the nature of the fabric or yarn. This bath is kept
lukewarm till the indigo deposited has been completely reduced.
Next we take off the green colour by exposure to the air or otherwise, and
remove the inspissating agent and continue by the operations as heretofore
performed.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
A process for printing indigo on any fabric or reserved threads, by starting from
insoluble refined or crude indigo, diluted in a mixture of water and an inspissating
agent likewise insoluble, for instance starch, the fabric after the impression being
soaked in a reducing bath, for example of hydrosulphite of lime, which reduces
the indigo upon the fabric; the re-oxidation of the indigo being then effected by
the ordinary processes.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.