Improvements in the Manufacture and Production of a Filementary Material, and Fabrics thereirom.
Year: 1898

page_text: Improvements in the Manufacture and Production of a Filementary
Material, and Fabrics thereirom.
I, CHARLES HENRY STEARN, of 47, Victoria Street, in the City of Westminster,
Electrician, do hereby declare the nature of my invention to be as follows:-
The object of my invention is to manufacture a filamentary material and
fabrics therefrom by the employment of a solution of cellulose made by treating
cellulose with strong alkali and then with carbon bi-sulphide and dissolving
the product in water. A process for the production of such a preparation is
described in the Specification of Letters Patent No. 8700 of 1892. 1 precipitate
the cellulose in filamentary form by projecting the solution thereof into a
precipitating solution such for instance as alcohol, brine, chloride or sulphate
of ammonium or other suitable precipitant and by providing means whereby
the cellulose solution can be drawn rapidly through the precipitating solution
the filaments formed can be obtained of a degree of fineness in accordance with
the speed adopted. The filaments may be produced singly or in any required
number simultaneously and can be wound on spools or bobbins and be woven
or otherwise combined to form the required fabrics.
The solution of cellulose should be as perfect as possible and any impurities
or imperfectly dissolved cellulose be filtered out before use.
After precipitation the product can be purified by sulphites or sulphurous acid
or other reagents and be bleached for instance with sodium hypochlorite.
Dated this 13th day of January 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.
Improvements in the Manufacture and Production of a Filamentary
Material, and Fabrics therefrom.
I, CHARLES HENRY STEARN, of 47, Victoria Street, in the City of Westminster,
Electrician, 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 object of my invention is to manufacture a filamentary material, and
fabrics therefrom, by the employment of a solution of cellulose made by treating

page_text: cellulose with strong alkali and then with carbon bisulphide and dissolving
the product in water. A process for the production of such a preparation (which
is commonly known as viscose) is described in the Specification of British Letters
Patent No. 8700 of 1892, I precipitate the cellulose in filamentary form by pro-
jecting the solution thereof into a precipitating or setting solution, or liquid,
alcohol, brine and sulphate of ammonium solution, for example, are precipitating,
or setting liquids, or solutions, but I have found that a solution of chloride of
ammonium gives the best results, as, at the proper strength, it is of a specific
gravity which will allow the cellulose solution to pass downwards therein and
it has the effect of immediately setting the said cellulose solution. By providing
means whereby the cellulose solution can be drawn rapidly through the precipi-
tating or setting solution the filaments formed can be obtained of a degree of
fineness in accordance with the speed adopted (the size of the orifice, or jet, and
the pressure on the vessel, being the same). A suitable strength of the chloride
of ammonium solution is one of a specific gravity of 1.050 to 1.060, but I do not
limit myself to this particular strength. The filaments may be produced singly,
or in any required number simultaneously, and can be wound on rollers, as a
preliminary to bringing the filaments into the form of hanks, in which form
they are more conveniently handled in the subsequent treatments for fixing,
purifying, bleaching and dyeing.
In the preparation of the viscose solution the greatest care must be taken
to render the solution perfectly homogeneous and free from all undissolved
particles of cellulose.
The ordinary viscose of commerce generally consists of a mixture of a true
solution of cellulose with a jelly-like substance, and contains many undissolved
fibres, or parts of fibres. This character remains in the viscose even after the
most careful filtering and if filaments be made of such a material the outlines,
when viewed under the microscope, will be seen to be more, or less, wavy, or
sinuous, presenting sections of unequal diameter, and of unequal strength, in
various parts of the filament.
The non-homogeneous nature of such a solution is clearly apparent by the
variations in colour displayed when viewed under the microscope in a thin film,
or layer, under polarised light.
A perfectly homogeneous solution can be obtained as follows:-
I first obtain the purest bleached cellulose and subject it to the action of alkali,
as in the well known process of mercerisation, continuing the process until the
solution of alkali has thoroughly penetrated through the mass. The cellulose
used should be as loose in structure as possible so as to admit readily of the
penetration of the alkali solution. When the mercerisation is thoroughly accom-
plished, the excess of alkali is squeezed out and the alkali-cellulose is treated
with carbon bisulphide. When the reaction is complete sufficient water is added
to make a solution containing say from 9 to 10 per cent. of cellulose, and the
mixture is thoroughly stirred for a considerable time by means of a mixer
revolving at high speed, the vessel containing the viscose being kept cool during
stirring.
The mixture must then be filtered very thoroughly and freed from air by the
air pump.
The solution, if carefully prepared and treated as aforesaid, will be perfectly
clear and structureless, or homogeneous, and of high viscosity, and is fit for
precipitation, or setting, as aforesaid, and filamentary material of great tensile
strength, and of even section through its whole length, is obtained.
The cellulose solution can be squirted through the jet under any suitable
pressure (air, or hydraulic, or mechanical,) into the precipitating or setting solu-
tion, or liquid, the orifice in the jet being of the requisite diameter to give the
size of filamentary material required which can be allowed to coil upon itself,
or be drawn off by a revolving pulley as may be desired.
The filament should be placed, and remain from 6 to 12 hours, in fresh chloride

page_text: of ammonium solution, or other setting solution or liquid, so as to remove soluble
products as thoroughly as possible.
After digestion in the cold the filamentary material is then removed from the
liquid and introduced for a few minutes into a boiling solution of the same
liquid, to regenerate the cellulose, by completing the decomposition of the sulpho-
carbonate, after which it is washed in boiling water to remove all traces of the
chloride. The resulting cellulose may then be purified in any suitable way, the
following being suitable. The thread is immersed in a hot solution of sodium
carbonate, (washing soda), and is left for some time in the solution. From this
it is well washed and immersed in a solution of sodium hypochlorite, or other
bleaching agent, till colourless. It is then thoroughly washed and may then
be treated with dilute acids and washed. It is then dried in the air under ten-
sion, or passed under tension through a heated chamber.
By providing a number of jets, or orifices, more than one filament can be
made at the same time, and if desired these may be twisted together to make
a compound thread or yarn, preparatory to the subsequent treatments for purifi-
cation, bleaching and dyeing.
The filaments produced may be reduced, polished, or otherwise acted upon by
passing them between rollers.
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 manufacture, for textile purposes, of filamentary material by pro-
jecting the aforesaid solution of cellulose (viscose) through a small orifice into
a precipitating or setting solution or liquid.
2. The manufacture, for textile purposes, of filamentary material by projecting
the aforesaid solution of cellulose (viscose) through a small orifice into a solution
of chloride of ammonium.
3. The manufacture, for textile purposes, of filamentary material by projecting
the aforesaid solution of cellulose (viscose) through a small orifice into a precipi-
tating or setting solution, or liquid, and drawing it therethrough.
4. The preparation of a filamentary material for textile purposes by first sub-
jecting the aforesaid solution of cellulose (viscose) to stirring and filtering, and
then projecting it from a small orifice, into a solution of chloride of ammonium
and drawing the same therethrough.
5. A filamentary material for textile purposes prepared from the aforesaid
solution of cellulose (viscose) substantially as hereinbefore set forth.
6. Fabrics made from filamentary material prepared from the aforesaid solu-
tion of cellulose (viscose) substantially as hereinbefore set forth.
TL 11011
1000
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.