Improvements in the Treatment of, or Finishing of, Manufactured, or Partially Manufactured, Materials from Cotton or other Cellulosic Fibres.
Year: 1890

page_text: Date of Application, 21st Mar., 1890
Complete Specification Left, 22nd Dec., 1890-Accepted, 24th Jan., 1891
PROVISIONAL SPECIFICATION.
Improvements in the Treatment of, or Finishing of, Manufactured, or
Partially Manufactured, Materials from Cotton or other Cellulosic
Fibres.
I, HORACE ARTHUR LOWE, of Heaton Moor, in the County of Lancaster, Technical
Chemist, do hereby declare the nature of this invention to be as follows:-
The process relates to improvements in the treatment of materials composed of
cellulosic fibres (such as cotton and flax) through which treatment, a better appearance
or finish and increased strength, and a greater power of assimilating colouring matters
and dyes is induced.
The material is impregnated with a strong solution of caustic soda, which combines
with the constituent cellulose, producing a transparent elastic material but, at the
same time, as in the case of spun and woven fabrics, great shrinkage occurs and this
shrinkage I prevent or recover by keeping the material mechanically stretched whilst
subjected to the treatment, or by subjecting it to a stretching operation immediately
after the treatment and during the subsequent operation of dissipating the combination
of the caustic soda with the cellulose, which occurs in the first bath, or generally
stated, before the cellulosic material so modified "sets," after the soda has been
removed by the water as hereafter stated.
In carrying out the process I first immerse the material in a bath prepared of a
strong solution of caustic soda, for a comparatively short time, say from 1 to
When in the bath or after
20 minutes, according to the texture of the material.
being removed therefrom, I stretch the material on a suitable mechanical arrangement
capable of drawing it back to its original dimensions. When removed from the bath
the material is thoroughly washed or rinsed with water. The action of the water
upon it is to wash out the chemical agent, and dissipate its chemical combination with
the cellulose and, while reproducing the cellulose, the fibres are in a condition to give
back the shrinkage under suitable stretching, without in any way nullifying the results
produced on the fibre by the caustic bath, either as regards finish, or capacity for
dyeing or printing.
After the washing and rinsing it may be still further treated with a dilute acid or
dilute solution of a bleaching compound in order to bleach it or remove any colour,
and to eliminate an trace of the alkaline bath.
The caustic sola washed out of the material is recovered from the wash water by
concentration, and is returned to the first operation to be used again, thus supplying
the place of a fresh supply of caustic soda; and as the commercial success of the
process will in some of its applications depend upon the return of caustic soda taken
out of the first bath; the second operation of treatment with water is so conducted
thit this can be done.
Thus a triplo combined process is carried out (a) combining the cellulose with
caustic soda (b) stretching the cellulose while so combined and (c) separating the
caustic soda from the cellulose, recovering it from the wash liquor and returning it to
the bath to combine again with the cellulose.
The material may be treated either in the form of cloth, yarn, or as may be
desired.
When applied to cloth I prefer to apply it during the process of bleaching, when
this process is about half or three quarters completed though it may be applied after
the bleaching is thoroughly completed, or before bleaching.
When applied to yarn, the yarn may be treated in the form of warps, or in hanks,
or in cops.
In either case while the material is in, or as soon as it leaves the first bath, it is

page_text: subjected to the stretching operation which is continued through the subsequent
operation of washing, rinsing, etc., until the cellulose has been reconverted and the
fibre " set."
The material so treated will possess all the advantages of being considerably
stronger; having a greater capacity of absorbing natural moisture; having a moro
regular, close, and glossy appearance; and of taking up many dyes and colouring
matters more readily and economically, while at the same time the objection of having
been shrunk is obviated.
"
Although this method of treatment produces what is known as a pure finish, yet
the same may subsequently be finished with size, china-clay, or other filling or loading
material at present employed in the finishing of some kinds of textile fabrics, or it may
be put through machines for beetling, calendering, or stretching.
Dated this 15th day of March 1900
WM. P. THOMPSON & Co.,
6, Bank Street, Manchester, Patent Agents.
COMPLETE SPECIFICATION.
Improvements in the Treatment of, or Finishing of, Manufactured, or
Partially Manufactured, Materials from Cotton or other Cellulosic
Fibres,
I, HORACE ARTHUR LOWE, of Heaton Moor, in the County of Lancaster, Technical
Chemist, 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:-
This invention relates to improvements in the process for the treatment of cellulosic
fibres described in the Specification of my Letters Patent No. 20,314 of 1889
whereby in fibres such as cotton and flax a better appearance or finish, increased
strength, and a greater power and economy of assimilating colouring matters and
dyes is induced therein.
In the process as described in the Specification of my previous Patent No. 20,314
of 1889 the material is impregnated with a strong solution of an alkaline hydrate,
preferably sodium hydrate, which combines with the constituent cellulose, producing
a transparent elastic material but, at the same time, in the case of spun and woven
fabrics, great shrinkago occurs and this shrinkage 1 eliminate by keeping the
material mechanically stretched whilst subjected to the action of or treatinent by
the sodium hydrate or by subjecting it to a stretching process or operation after
the sodium hydrate bath, but necessarily before the fabric has lost its temporarily
pliable condition. This pliable state only occurs when the combination of the soda-
cellulose is broken up,-previous to that point the material if stretched out returns
again (when the stretching agent is removed) to its shrunk dimensions--it is
"elastic" not "
pliable," this "elasticity" vanishes at the point in the process
indicated, but "pliability" remains (but only for a limited period of time during
which it gradually decreases and providing the fabric be not dehydrated by hot-
drying etc.). It is whilst in this peculiar and transitory state of pliability that I
recover the dimensions and yet retain the other properties induced by the combination
with the soda above described.
In carrying out the process the material is immersed in a bath containing a con-
centrated solution of sodium hydrate of a density of from 25° to 75° Twaddle for a
period of from 1 to 15 minutes according to the texture of the material and the
density of the solution.
The action of the soda on the fibre modifies the cellulose contained therein and
causes the fibre to shrink very considerably and although by subsequent washing all
traces of the sodium hydrate may be eliminated the altered condition of the fibre
and the shrinkage remains.
The material when it emerges from this bath and throughout the remainder of the

page_text: process is in a very pliable and elastic condition and the shrinkage can all be
recovered by stretching the material either throughout the bath and maintaining it in
that stretched condition until it has passed through the washing process and has thus
set, or during the subsequent operation of washing to remove the soda, or after the
washing is complete before the material has dried or begun to set. I find that it is
better in treating yarn in hanks to carry out the stretching process during the
whole treatment that in treating heavy cloths and warp yarns the stretching
process is better applied while the operation of washing is proceeding; and that
for ordinary cloth and yarn in the cop the stretching process is best carried out after
the breaking-up of the combination by washing is complete, but before it is "set"
hy standing or by hot-drying.
When removed from the sodaizing bath the material is thoroughly impregnated or
rinsed with water (preferably warm). The washing operation is conducted in such a
manner as to reverse the combination of the soda and extract the soda (in the form of
sodichydrate) with the least possible dilution of the wash waters. To effect this a number
of sprays of warm water may be directed against the fabric or it may be washed in
baths or troughs with minimum volumes of water aided by suction, or pressure or by
mechanical squeezing. The action of the water upon the fibre is to wash out the
chemical agent, and disassociate its chemical combination with the cellulose and,
while reproducing the modified forin of cellulose, the fibres are in a fit condition to
give back the shrinkage under suitable stretching, without in any way nullifying the
results produced on the fibre by the sodaizing bath, either as regards finish, or
capacity for dyeing or printing.
The fibre so treated is free from soda and the last traces may be neutralized with a
dilute acid solution.
The sodium hydrate eliminated from the cellulosic compound as above described is
in such a state that it can be regenerated. The solution is concentrated by a multiple-
effect evaporator or other concentrator to a sufficient degree viz. 70°-80° Twaddle
and then returned to the bath the density or strength of which will thus be kept
constant and is thus available for reproducing the same modification upon the
following batches of material. If it is found that this soda solution obtained by the
decomposition of the cellulosic compound contains impurities abstracted out of or
aken up from the fibres it may when necessary be filtered or purified before being
returned to the process.
Thus a triple combined process is carried out, consisting in (a) the treating of the
cellulose with sodium hydrate (b) the stretching of the cellulosic fabric whilst in the
pliable condition before it "sets" rigid and (e) the separating of the sodium hydrate
from the cellulose recovering it from the wash liquor and returning it to the bath to
react again upon the cellulose.
The material may be treated by this process in the form of woven lengths of cloth
or as yarn in the hank or
Woven lengths of material or after being warped.
or warps are treated continuously, they are passed slowly
through the bath, then through rollers or squeezers which remove most of the liquor
and afterwards passed on to washing tanks where as above described the decomposition
is carried out with as little dilution as possible. And during the operation of washing
or subsequent to it the material is stretched by any suitable machine such as is at
present employed to stretch fabrics.
Yarn in the form of cops or hanks may be treated in machines such as are at
resent in use for cop dyeing and for hank dyeing or in other similar machines which
may he adapted or constructed for the purpose which will allow of the time of
immersion required, of the use of a minimum quantity of the decomposing agent and
the subsequent recovery and regeneration of the soda eliminated by it.
In the case of hanks however it is desirable to keep them stretched during all the
operations and until the fibres have " set" rigid.
This modified material possesses the advantages of being considerably stronger; of
having greater capacity of absorbing natural moisture; of having a more regular close
and glossy appearance, together with the property of attaining a deeper shade with the

page_text: use of the same quantity of dye, and of attaining depth and quality of colour hitherto
unattainable with certain dyes, the colours so dyed being faster to both chemical and
actinic destruction. The stretching does not alter any of these properties attributable
to the sodaizing of the fabric while at the same time all loss of length is obviated, the
thickening or increased coarseness of the fibres is reduced and more than that the
fibres are even finer than in the fabric before treatment.
The cloth may subsequently, if desired, be finished by any of the ordinary methods
with size, china-clay or other filling or loading material at present employed in the
finishing of some kinds of textile materials, and may be beetled and callendered.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
1. The process of treating cellulosic fibrous material which consists in subjecting it
to a strong solution of an alkaline hydrate preferably sodium hydrate and stretching
the alkalized fibre during or subsequent thereto before the fibres set rigid to provent
or recover shrinkage substantially as and for the purpose described.
2. The triple process which consists in treating cellulosic fibres with a strong
solution of sodium hydrate, stretching the cellulosic fabric whilst in a pliable condition
before it sets rigid to recover or prevent shrinkage, and separating the soda as sodium
hydrate from the cellulose recovering it from the wash liquor and returning it to the
bath to again react upon cellulose substantially as described.
Dated this 19th day of December 1900
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.