Improvements relating to the Treatment of Silk and other Fibres.
Year: 1886

page_text: Date of Application, 14th Dec., 1886.
Specification Accepted, 25th Jan., 1887
[Communicated from abroad by HENRY RICE RANDALL, of Brooklyn, New York,
United States of America, Chemist.]
Improvements relating to the Treatment of Silk and other Fibres.
I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, 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:—
The first part of my invention relates to the treatment of silk fibre, but more
especially to raw and waste silk, and the purpose thereof is to so treat the fibre that it
may be readily reeled without necessarily removing the gummy matter therefrom. It
is also applicable to the treatment of cocoons without change.
In carrying out this part of my invention I make use of a solution of commercial
acetic acid in water in the proportion of about one to three ounces of the acid to a
gallon of water. Or I may, however, combine with the acetic acid, a small proportion
of sulphuric acid the substantial proportions being one quarter of an ounce of sulphuric
acid and one ounce of acetic acid to a gallon of water. This formula may be used
with equally beneficial results.
In applying my process to the treatment of silk fibre, raw or waste silk, or cocoons,
I place the fibre to be treated in the solution specified, the latter being raised to a
temperature of about 120° to 130° F. The solution is retained at or about at this
temperature for several hours, being never allowed to rise to the boiling point, and
after the treatment has progressed to the requisite stage (which can readily be
determined by an examination of the fibre) the latter is removed, washed, dried and
then subjected to the ordinary processes.
I may use sulphuric acid in place of acetic acid alone and the results are not
dis-similar save in the degree of perfection to which the result is carried.
The temperature of the solution to which the silk fibre, raw or waste silk or cocoons
is or are subjected, may vary considerably from the degree mentioned, the sole
limitation being that the solution shall not be allowed to rise to, or near, the boiling
point.
The proportions of the acetic acid to the gallon of water, or of the acetic acid and
sulphuric acid thereto may be considerably varied without departing from the
invention

page_text: It is not my purpose in this part of my invention to remove the gum from the fibre,
but to disintegrato it so that the tube can be reeled without difficulty.
Heretofore various methods have been employed for this purpose, among which is
that of "Guinon," who uses a steep of soda lye at 212° F and follows it with a bath of
dilute sulphuric acid; also the methods invented by "Pelangie" and "Bedu," who
use a bromine solution and then a bath of tartaric or citric acid.
These processes differ from mine in the fact that they contemplate the removal of
the gum as the preliminary step. Moreover the use of sulphuric acid in the one and
of tartaric or citric acid in the other, after the gum is removed, injures the fibre, and
moreover the effect produced is as different as the difference between the agents used.
I employ commercial acetic acid, which usually contains robo part by weight of
sulphuric acid. This acid (acetic) enters into my bath in the proportion of substantially
four parts to one part of sulphuric acid dilute. The fibre, without removing the gum,
is steeped in this for a suitable period at a temperature which is never allowed to rise
to the boiling point.
The second part of my invention relates to the treatment of silk cocoons and their
fibre, or silk waste, or other raw silk, as well as vegetable fibres, but it has especial
reference to the treatment of what are known as the wild Tussah cocoons the purpose
being to remove the natural color of the fibre and to cleanse the same by separating
the gummy matter, leaving the fibre without color and in a lustrous and perfectly clean
condition, ready for the carder and spinner.
While this part of my invention is, as already stated, applicable to the treatment
of other fibres, it is especially intended for use with the wild Tussah cocoons,
which in their natural state, contain a coloring matter of a brownish or yellowish cast,
which has hitherto prevented the use of this quality of fibre to any considerable extent,
as it will not admit of being dyed in light shades, nor does it readily take the darker
dyes, by reason of the presence of the natural color referred to. In consequence, the
wild Tussah cocoon has long been comparatively speaking, a cheap or even worthless
product.
It is one of the purposes of this part of my invention to so treat this class of
silk fibre as to render it available for all the purposes of the more valuable grades
enabling it to be dyed of any one of the light and delicate tints, thoroughly
disintegrating the fibre and imparting to it a high lustre without injuring its
strength or impairing its quality. In practising the invention, I first take the
wild Tussah cocoons and thoroughly wash them in warm water, after which they
are dried, and preferably, sprinkled with some saponifiable oil, such as lard oil,
although any other may be used.
I then boil the cocoons in a solution of any one of the following salts viz. :-
a stannate, aluminate, plumbate, silicate or borate of either sodium or potassium,
or an alkaline solution of zinc oxide, I may also use ammonio-plumbic oxide,
ammonio-zinc oxide, or ammonio-stannic oxide.
The solution may consist of any one of the above named salts in the proportions
substantially, of one or two ounces to a gallon of water, though these proportions
may be considerably varied. I usually make a saturated solution of the salt and
then add it to the water in the amount desired.
The boiling in this solution may be continued for a time which must be determined
by the results produced the state of the fibre at any stage being a sufficient guide to
the operator.
After boiling until decolorization and disintegration are both effected the solution is
drawn off and the fibre is thoroughly washed with hot water removing thereby all
colouring matter which has been rendered soluble by the treatment pursued, or which,
though insoluble has been removed from the fibre by the solution and remains mingled
with other foreign matter in the form of small dark particles among the fibre, and salts
which remain still in the fibre, which is afterward dried. It is then ready for carding
and spinning.
The preliminary washing of the cocoons may or may not be practised without
essentially modifying the final result.

page_text: Also, in treatment with the solution as above described, it is not necessary to raise
the temperature to the boiling point, since the same result may be accomplished by
steeping the cocoons at a lower temperature, but for a proportionately longer time.
The essential steps of my process therefore are the treatment with a solution of one
of the metallic salts mentioned above and subsequently washing the fibre.
In treating the cocoons with saponifiable oil as described, the glycerine thereof is
liberated directly in the fibre. When soap is used in place thereof this rosult is not
produced, as the glycerine is formed without and will not enter the fibre.
The chemical salts named above have the property of yielding the alkali of the base
slowly and consequently the action of the same upon the fibre is much less violent and
less corrosive, while at the same time it is more complete and free from all danger of
injury to the silk.
By this part of my invention I produce from the wild Tussah cocoons a raw silk
fibre which is white or whitish, is possessed of great strength, has a high lustre and
which may be dyed of any light and delicate tint equally well as with silk of the most
costly grade.
Having now particularly described and ascertained the nature of the said invention
and in what manner the same is to be performed as communicated to me by my foreign
correspondent, I declare that what I claim is
First. In the treatment of silk fibre, waste and raw silk and cocoons, the process
hereinbefore set forth, consisting in subjecting the same before removing the gum to
the action of a solution of acetic acid in water in the proportions and at the temperature
specified with reference to the first part of my invention.
Second. In the treatment of silk fibre, waste and raw silk and cocoons the process
set forth, the same consisting in subjecting said fibre before removing the gum to the
action of a watery solution of acetic acid and sulphuric acid in substantially the
proportions specified, at a temperature below the boiling point, substantially as
described with reference to the first part of my invention.
Third. The process hereinbefore set forth for the treatment of the wild Tussah
cocoons, or other silk fibre or silk waste, said process consisting in first washing the
cocoons, then subjecting them to the action of a heated solution of stannate of sodiuin
or in lieu thereof one of the other chemical salts specified, then washing in hot water
and finally drying the same, substantially as described with reference to the second
part of my invention.
Fourth. The process hereinbefore set forth for the treatment of the wild Tussah
cocoons or other silk fibre or silk waste, said process consisting in first washing the
cocoons, or fibres then treating them with a saponifiable oil, then treating them in a
hot solution of stannate of sodium or in lieu thereof one of the other chemical salts
specified, then washing and finally drying the same substantially as described, with
reference to the second part of my invention.
Fifth. The process hereinbefore set forth for the treatment of the wild Tussalı
cocoon or other silk or vegetable fibre said process consisting in first washing the
cocoons or fibres, then sprinkling them with a saponifiable oil, then subjecting them to
the action of a heated solution of stannate of sodium or in lieu thereof one of the other
chemical salts specified, in the proportions substantially as specified, then washing with
hot water and finally drying, substantially as described with reference to the second
part of my invention.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C.,
Agents for the Applicant.