AN IMPROVED PROCESS FOR TREATING JUTE, HEMP, WOOD, OR OTHER FIBROUS MATERIALS TO PREPARE THEM FOR USE PROVISIONAL SPECIFICATION USE IN TEXTILE AND OTHER MANUFACTURES, AND FOR SIMILAR PURPOSES
Year: 1880

page_text: LETTERS PATENT to Charles Frederick Cross, of Brentford, in the County of
Middlesex, for an Invention of "AN IMPROVED PROCESS FOR TREATING JUTE,
HEMP, WOOD, OR OTHER FIBROUS MATERIALS TO PREPARE THEM FOR USE
PROVISIONAL SPECIFICATION left by the said Charles Frederick Cross at
" AN
the Office of the Commissioners of Patents on the 30th November 1880.
CHARLES FREDERICK CROSS, of Brentford, in the County of Middlesex.
IMPROVED PROCESS FOR TREATING JUTE, HEMP, WOOD, OR OTHER FIBROUS
MATERIALS TO PREPARE THEM FOR USE IN TEXTILE AND OTHER MANUFACTURES,
AND FOR SIMILAR PURPOSES."
My Invention relates to an improved process of treating jute, hemp, flax,
straw, esparto-grass, wood, or other fibrous materials for loosening, separating,
disintegrating, softening, bleaching, or otherwise preparing the same for the
subsequent operations to which they may have to be subjected in the course of
manufacture into textile fabrics, paper, or otherwise. One important object of the
said Invention is to provide means whereby jute, hemp, flax, or similar fibrous
materials may be protected from the well known injurious effects of superheated
steam or water to which such materials have to be subjected in the course of
manufacture into various articles; and the said Invention may be advantageously
applied to the raw material, to yarn made therefrom, or to fabrics woven thereof
under all circumstances or conditions in which the said material may require for
any purpose to be subjected to the action of such steam or water.
The action of water or steam at a temperature exceeding 100° centigrade is
known to be destructive to jute and similar fibrous materials, the fibre (jute) being
thereby brought into a friable condition, becoming completely disintegrated, and
acquiring a mahogany red colour. This disintegrating and discolouring action
varies in any given fibre with the temperature and time of exposure; and in a
series of fibres with the ratio of the non-cellulose to the cellulose constituents of the
several members (see Dr. Forbes Watson's report on the Rhea fibre, 1875, and
Bevan & Cross on the chemistry of bast fibres, 1880). Thus in the case of bleached
cotton or flax (i.e., cellulose) the fibre is scarcely attacked under such conditions of
this action as would determine the total disintegration of the jute fibre, in which

page_text: the non cellulose constituents are estimated at from 25 to 30 per cent. of its weight.
The attendant loss of weight which the fibre sustains reaches from 20 to 30 per
cent., or even a higher limit. Amongst the soluble products thus removed are
certain acid bodies, which cannot fail to act destructively under these conditions
upon the cellulose of the fibre itself. The formation of these occurs even at the
ordinary boiling temperature (100° centigrade), as may be observed by heating the
fibre in a retort with water for some time; then removing the fibre, and adding
sodium acetate, when a distillate of acetic acid is obtained. The presence of sodium
sulphite I have found entirely to prevent such formation of these acid bodies under
the conditions named, and to protect vegetable fibres from the destructive and
discolouring action of the superheated water to which they may require to be
subjected. It is this protective action which forms the basis of my process, which
consists therefore essentially in subjecting the aforesaid vegetable substances to the
action of sulphite of sodium or some other neutral salt having similar properties,
such as other metallic sulphites or alkaline hyposulphites or thio-sulphates, in
presence of water or steam at any required temperature.
In carrying the said Invention into practice I prepare a solution (whose strength
may be from one half to two per cent.) of neutral sodium sulphite or its equivalent,
as above stated, and I place the jute or other material to be treated in a suitable
vessel containing this solution, allowing it to remain therein for a period of from
two (2) to eight (8) hours at a pressure of from twenty (20) to one hundred and
twenty (120) lbs., according to circumstances. When treating jute I may take the
ordinary fibre in its entire length, or the root-ends, known as "cuttings" may be
treated.
Under the above described treatment the fibre becomes completely softened, and
is bleached to a considerable extent, and when removed from the solution is quite
ready for use in the manufacture of yarn, paper-pulp, or other materials to which
it may be applicable. by the ordinary methods of mechanical and other treatment.
Flax, hemp, jute, and the like treated by my Invention are thereby cleaned,
softened, and so far bleached as to be capable of taking dye of pale or brilliant
shades, but if perfect whiteness be desired a subsequent bleaching operation by any
ordinary process may in some cases be necessary. Moreover by my said Invention
the strength of the fibre is practically unimpaired, and the loss in weight and
amount of decoloration are considerably less than is the case when such materials
are treated by ordinary methods in which alkali is employed.
Fibrous materials of the kind above mentioned which have to be subjected to the
action of superheated steam or water for any purpose are, according to my
Invention, subjected to the solution above described, so as to become impregnated
with the salt, that is to say, the sulphite of sodium or equivalent material, and may
then be exposed without danger to the said steam or water.
The details of my process may be modified to suit special circumstances; for
instance the treatment may be carried into practice at the ordinary boiling
temperature, and in certain cases the sulphite may be used in conjunction with an
alkali, and its quantity be varied. The time of exposure to the action will be
varied according to the result required.
If protection against the effect of steam or water be the only object sought, the
desired result may be obtained by making the solution at a strength of one half
per cent., but where a bleaching effect is desired the strength must be increased
from one half to two per cent., according to circumstances.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Charles Frederick Cross in the Great Seal Patent Office on the
30th May 1881.
CHARLES FREDERICK CROSS, of Brentford, in the County of Middlesex. "AN
IMPROVED PROCESS FOR TREATING JUTE, HEMP, WOOD, OR OTHER FIBROUS
MATERIALS TO PREPARE THEM FOR USE IN TEXTILE AND OTHER MANUFACTURES,
AND FOR SIMILAR PURPOSES."
My Invention relates to an improved process of treating jute, hemp, flax,
adansonia, or other bast fibre or fibrous materials for loosening, separating,
disintegrating, softening, bleaching, or otherwise preparing the same for the
subsequent operations to which they may have to be subjected in the course of
their manufacture into textile fabrics, paper, or otherwise. The said Invention
consists more particularly (1), in subjecting the said fibrous materials to the action
of hot aqueous solutions of metallic sulphites or salts of similar chemical action by
which the softening and solvent effect of the water is enhanced, and at the same
time the fibres are protected thereby and by the chemical action of the salts from
the destructive and discoloring effects which otherwise occur; and (2), in treating
fabrics (to which coloring matter is to be applied, as in the ordinary methods of
calico printing), by impregnating the same prior to the application of the color with
the sulphite or similar salt to ensure that the fixation of the colors by steaming the
fabric shall be effected without injury to the latter.
My improved process is based upon recent researches into the chemistry of bast
fibres (see Bevan and Cross, Chemical Society Journal, vol. 38, page 666, and
Chemical News, vol. 42, page 77, and vol. 43, page 160) in which jute has been
taken as the type. In these researches it has been shewn that the said fibres are
built up of, or may be decomposed into, several bodies or substances, that is to say,
(a), an aromatic body closely related to the tannins; (b), a form of cellulose which
is easily decomposed under oxidizing conditions with formation of acid bodies of
the pectic class; and (c), a more stable form of cellulose resembling the basis of the
cotton fibre. The action of superheated steam upon these fibres considered as made
up of the substances thus classified as a, b, c, is to develope brown coloring matter
from the substance (a), and acids from (b), and these latter acting upon (c)
disintegrate it with formation of bodies allied to glucose. The steaming of
bleached jute, as in the process of printing, and even of the raw fibre (Dr. Watson's
report on the rhea fibre) has been found to produce a greater or less discoloration
and a disintegration of the fibre, frequently amounting to destruction, while the
presence of sodium-sulphite, or a salt or salts of similar properties, has been found
to obviate these changes entirely and to preserve the integrity and color of the
fibre, a result which follows from the action of such salts upon the various bodies or
materials into which the jute fibre is above stated to be decomposable.
I will now proceed to describe the method of carrying my Invention into practice
in its several applications.
In the printing of bleached goods, such as jute, hemp. and the like, the fibre is
impregnated with sodium-sulphite prior to the application of color thereto in the
printing machine. For this purpose the goods after being well washed, to remove
the solutions employed in bleaching, and mangled or otherwise treated to remove
as much moisture as possible, are passed in any convenient manner through a
solution of sodium-bisulphite, so diluted with water as to contain 2% more or less,
of its weight of sulphurous acid. The excess of the solution in the goods or
materials is then removed by again mangling the same or treating them in a
hydro-extractor as occasion may require and is returned to the bath. The latter
must be maintained at a constant strength and volume by periodic additions of the

page_text: concentrated bisulphite solution. The fabric thus treated is allowed to lie for a few
hours, whereby an additional improvement in its color is effected, and it is then
dried in any suitable manner. The above described solution in addition to effecting
the objects above specified, also acts as an antichlore in cases where the fabric has
been treated with a solution of bleaching powder, and at the same time neutralizes
any mineral or other powerful acid added either during the bleaching operation or
formed from the constituents of the fibre.
During the process of drying the fabric sulphurous acid escapes; the dry cloth
on exhaustion with water gives a solution which is neutral or slightly alkaline,
that is to say, is impregnated with normal sodium sulphite.
After the fabric or cloth has been treated as above described color mixtures may
be applied thereto by any of the ordinary printing machines or processes, and the
fabric may then be steamed to develope and fix the color without injury to such
fabric. In cases where the presence of a sulphite may be presumed to influence
the development of the color preliminary tests should be made, and the mixtures
modified accordingly. This precaution however, in most cases, will be unnecessary,
the slight amount of mutual influence being probably due to their mode of
application.
01
For the treatment of yarns and fabrics of jute, hemp, flax, or the like, to cleanse
the same from "batching" oils and other impurities, and at the same time effect a
partial bleaching of the fibre, I employ two processes, according to the required
extent of action upon the said fibre, that is to say, firstly, I treat the fibre in an
open vessel with solutions of the neutral sulphite containing from 1 to 2% more
or less, of sulphurous acid (as sulphite), and secondly, I boil the fibre in a kier or
other suitable vessel under a pressure of steam of five to fifteen pounds per square
inch with a solution similar to that used in the first process. The duration of the
action of the solution will obviously depend upon the judgment of the operator.
From one to two hours will however, in most cases, suffice to produce the best
results. Minor details will be determined according to the nature of the material
to be operated upon, and need not therefore be stated here.
For the treatment of bast fibres and similar substances to render them capable
of application to textile purposes, and of being manufactured into paper, I proceed
as follows, that is to say:-Two tons of jute cuttings, for example, are placed in a
"vomiting" or other suitable boiler, and two thousand gallons of water are added
thereto, together with one hundred and fifty pounds of neutral sodium sulphite.
The boiling is then proceeded with under a pressure of about thirty five pounds to
the square inch for about six hours. By this treatment the fibres are completely
softened and bleached to a grey color in the case of jute or hemp, and approximating
to a white color in the case of adansonia. When the fibres are to be used for the
manufacture of paper they are then removed to the washers, bleached, and further
treated by the ordinary processes. When they are to be used in textile manu-
factures the fibres must be freed from the encrusting matter, which is now softened
and easily removable, and must be crushed and washed in such a manner as to
maintain the parallelism of the fibres.
Certain incidental advantages of this treatment may be here mentioned, namely,
first, the solution being and remaining slightly alkaline exerts no corrosive action
upon iron, and therefore any ordinary boilers may be utilized, and, secondly, the
conversion of sulphite by oxidation into sulphate being small the solution may be
heated several times upon fresh charges of fibre, always provided the original
strength of the sulphite-solution is kept up by additions of the salt. When
however the dissolved organic matters have accumulated beyond a certain point,
which may be easily determined by the operator, the solution must be rejected.
In the treatment of wood and other vegetable substances in which the encrusting
matters are largely developed their disintegration will be facilitated by the addition
of caustic soda, in the proportion of 15% to 30% of the weight of the sulphite,
and by increasing the pressure in the boiler to from eighty to one hundred and
twenty pounds per square inch.

page_text: Having thus fully described my said Invention, and the manner of performing
the same, I wish it understood that the proportion of the reagents, the duration of
the operations, the pressure of steam, and the temperature, may be varied according
to the nature or quality of the materials to be treated. I also wish it understood
that I am aware that in the Specification of former Letters Patent, No. 292+,
A.D. 1866, there is described a process of treating vegetable substances applicable
to the manufacture of paper-pulp and fibres, in which process a solution of
sulphurous acid, with or without the addition of sulphites, is used as the agent
"for dissolving the intercellular or cementing constituents of the vegetable
substances," and special apparatus is provided to enable this acid solution to be
safely employed. But this process is objectionable for the following reasons, viz.,
the necessity for such special apparatus, the difficulties attendant upon the making
and keeping of the sulphurous acid, and the destructive effect of this acid upon the
fibres or upon the coloring matters used for printing, whereas my Invention is
entirely free from these disadvantages, and I claim,-
First. The treatment of fibrous materials with water or steam at a high
temperature in contact with sulphites, or with salts of equivalent chemical action,
with or without the further addition of alkali, to fit them for use in the manufacture
of textile fabrics or of paper, substantially as set forth.
Second. The modification of my Invention for the impregnation with sulphites
of vegetable fabrics or fibres which are to be subjected to a high temperature, with
or without water or steam, so that the action thereof may. proceed with the least
possible injury to the color and strength of the fabric, substantially as set forth.
In witness whereof, I, the said Charles Frederick Cross, have hereunto set
my hand and seal, this Twentieth day of May, in the year of our Lord One
thousand eight hundred and eighty one.