Improvements in the Treatment of Vegetable Fibres.
Year: 1897

page_text: Date of Application, 2nd Dec., 1897
Complete Specification Left, 23rd Aug., 1898 --Accepted, 29th Oct., 1898
Improvements in the Treatment of Vegetable Fibres.
I, CHARLES WETHERWAN, of Best, Rensselaer County, in the State of New York,
United States of America, Manufacturer, do hereby declare the nature of this
invention to be as follows:-
My invention relates to a process of degumming China grass and other vegetable
textile fibres aud of removing the bark and it consists essentially in subjecting
the fibres to the action of a solvent solution (or solutions) prepared as hereinafter
described, the operations being performed by causing the solution to circulate
through the fibres under steam pressure in a digester.
For the operation of degumming I prepare the solvent solution in the following
manner and of the following ingredients:-I dissolve 20 pounds of caustic soda
in 8 gallons of water and cool it to a temperature of 80° Fahrenheit. I also
melt 130 pounds of tallow or fat free from salt bringing it to a temperature of
120° Fahrenheit and then pour the caustic soda solution slowly into the melted
fat, stirring slowly until the two ingredients are thoroughly incorporated and the
mixture becomes smooth. I then let it stand for 24 hours, or until saponification
ensues, after which it is re-melted with an addition of 100 pounds of fat and
after it is thoroughly dissolved I add 30 gallons of water, mixing it thoroughly.
I then combine 30 pounds of glycerine with 8 gallons of water and stir it into the
emulsion when nearly cold. Of this emulsion I take from 4 to 8 ounces per gallon
of water to form the solvent solution to be used for degumming the fibres.
A suitable apparatus for performing the operation of degumming the fibres
consists of a digester adapted to sustain a steam pressure of, say, 100 pounds and
a cage supported therein and containing a series of superposed trays or baskets
made of woven copper wire, each basket being open at top and resting on the one
below and each having a spiral partition between the convolutions of which the
fibres are placed so as to be kept straight or free from entanglement and be sup
jected uniformly to the action of the solvent solution, the use of the superposed
baskets preventing the mass of fibres from packing together tightly and so being
unequally acted on. In order to facilitate placing the baskets in the cage the
latter has three upright members connected to top and bottom frames, two of the
uprights being wide enough apart to allow of the baskets being slid into the cage
laterally as it is raised above the open top of the digester for which purpose the
cage is suspended from suitable tackle for raising and lowering it.
Into the upper part of the digester leads a liquor-circulating pipe, terminating
within the digester in a nozzle which is removably fitted to allow of raising and
lowering the cage, the nozzle being upwardly directed so that the liquor is projected
against the top of the digester and thereby distributed uniformly over the charge
of fibres. The pipe is connected to a coil within a heater the coil being connected
to the delivery of a centrifugal pump whose suction pipe is connected to the bottom
of the digester. A steam boiler is connected by a pipe with the heater for the
purpose of conveying steam into the space surrounding the coil and by another

page_text: pipe with the liquor circulating pipe near the point where the latter enters the
digester so that the solvent solution may, if necessary, be heated by live steam as
well as by means of the heater. Generally the liquor would be heated only by
its passage through the steam-heated coil and the necessary pressure thereby
established within the digester without diluting the solution by the admixture of
live steam.
When the solution is at the proper temperature the circulation through the
heating coil may be cut off and the circulation maintained without passing through
the heuter. When the operation is completed the liquor containing the gummy
matters in solution is discharged and plain water introduced and circulated through
the digester until the fibres are thoroughly cleansed and then the cage containing
the baskets is removed from the digester.
Instead of, or in addition to, the heating coil I may employ a steam heating coil
within the digester itself.
"
For the subsequent operation of removing any remaining gummy matter and of
decorticating or removing the bark I prepare a solution as follows:-I take one
part by weight of caustic soda and three parts of carbonate of soda or ammonia-
soda ash and dissolve in the proportion of from three-fourths to one pound of
this mixture per gallon of water, the above named proportions of the ingredients
and the strength of the solution being however variable but only to a slight extent.
With the solution of hydrated carbonate of soda thus formed I treat the fibres for
about two hours under a steam pressure of about 80 pounds and at a corresponding
temperature in the digester above described, the operation being conducted in the
same way as the degumming operation first above described, it being important to
observe that by using the separate heater for the solution without the injection of
live steam the dilution of the solution by water of condensation is avoided and it is
unnecessary to subject the fibre to a solution of excessive strength in order to com-
pensate for this dilution. When completed, the solution is drawn off and the fibres
are washed by the circulation through the digester of plain hot water or of cold
water heated by the injection of steam.
Dated this 2nd day of December 1897.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improvements in the Treatment of Vegetable Fibres.
I, CHARLES WETHERWAX, of Best, Rensselaer County, in the State of New York,
United States of America, Manufacturer, 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:-
-
My invention relates to a process of degumming China grass and other vegetable
textile fibres and of removing the bark, and it consists essentially in subjecting
the fibres to the action of a solvent solution (or solutions) prepared as hereinafter
described, the operations being performed by causing the solution to circulato
through the fibres under steam pressure in a digester.
For the operation of degumming, I prepare the solvent solution in the following
manner and of the following ingredients: -I dissolve 20 pounds of caustic soda
in 8 gallons of water and cool it to a temperature of 80° Fahrenheit. I also
melt 130 pounds of tallow or fat free from salt bringing it to a temperature of
120° Fahrenheit and then pour the caustic soda solution slowly into the melted
fat, stirring slowly until the two ingredients are thoroughly incorporated and the

page_text: mixture becomes smooth. I then let it stand for 24 hours, or until saponification
ensues, after which it is re-melted with an addition of 100 pounds of fat and
after it is thoroughly dissolved I add 30 gallons of water, mixing it thoroughly.
I then combine 30 pounds of glycerine with 8 gallons of water and stir it into the
emulsion when nearly cold. Of this emulsion I take from 4 to 8 ounces per gallon
of water to form the solvent solution to be used for degumming the fibres. In
order to remove the bark, and for the purpose of completing the degumming I
submit the fibres to the action of a hot solution of caustic soda and carbonate
of soda under steam pressure, as hereafter described.
A suitable apparatus for performing these operations is illustrated in the
accompanying drawings wherein Figure 1 is an elevation of the entire apparatus,
the digester being in section. Figure 2 is a plan of one of the trays for holding
the fibres. Figure 3 is a top plan and Figure 4 a sectional plan of the cage.
A is a digester provided with a removable cover secured by bolts and adapted to
sustain a steam pressure of, say, 100 pounds and B is a cage supported therein
and containing a series of superposed trays or baskets C made of woven copper
wire, each basket being open at top and resting on the one below and each having
a spiral partition c between the convolutions of which the fibres are placed so as
to be kept straight or free from entanglement and be subjected uniformly to the
action of the solutions, the use of the superposed baskets preventing the mass of
fibres from packing together tightly and so being unequally acted on.
to facilitate placing the baskets in the cage, the latter has three upright members
connected to top and bottom frames, two of the uprights being wide enough apart to
allow of the baskets being slid into the cage laterally as it is raised above the
open top of the digester for which purpose the cage is suspended from suitable
tackle for raising and lowering it.
In order
Into the upper part of the digester leads a liquor-circulating pipe D terminating
within the digester in a nozzle which is removably fitted to allow of raising and
lowering the cage, the nozzle being upwardly directed so that the liquor is pro-
jected against the top of the digester and thereby distributed uniformly over the
charge of fibres. The pipe D is connected to a coil at D' within a heater E, the
coil being connected to the delivery of a centrifugal pump whose suction pipe D
is connected to the bottom of the digester A. A steam boiler G is connected by
a pipe H with the heater E for the purpose of conveying steam into the space
surrounding the coil and by another pipe I with the liquor circulating pipe D near
the point where the latter enters the digester so that the solvent solution may, if
necessary, be heated by live steam as well as by means of the heater. Generally,
the liquor would be heated only by its passage through the steam-heated coil 1)
and the necessary pressure thereby established within the digester without diluting
the solution by the admixture of live steam. J is a steam trap for removing water
of condensation from the heater E. When the solution is at the proper temper-
ature, the circulation through the heating coil D' may be cut off by suitable stop
valves and the circulation maintained through the bye pass K. The liquor is
circulated through the digester in the downward direction so that all tangling of
the fibres is prevented.
The approximate duration of the first or degumming operation is about one hour
under a pressure of 80 lbs. per square inch and a corresponding temperature
of 325° Fah.
When the first or degumming operation is completed the liquor containing the
gummy matters in solution is discharged through a pipe L and plain water intro-
duced and circulated through the digester until the libres are thoroughly cleansed
and then the cage containing the baskets is removed from the digester unless the
fibres are to be submitted to the second operation as hereafter described. Instead
of, or in addition to, the heating coil D for the liquor I may employ a steam
heating coil within the digester itself.
For the second operation of removing any remaining gummy matter and of
decorticating or removing the bark prepare a solution as follows:-I take one

page_text: part by weight of caustic soda and three parts of carbonate of soda or ammonia-
soda ash and dissolve in the proportion of from three-fourths to one pound of this
mixture per gallon of water, the above named proportions of the ingredients and
the strength of the solution being, however, variable but only to a slight extent.
With the solution of hydrated carbonate of soda thus formed I treat the fibres for
about two hours under a steam pressure of about 80 pounds and at a corresponding
temperature in the digester above described, the operation being conducted in the
same way as the degumming operation first above described, it being important to
observe that although caustic soda is an ingredient of the solution it will as used
in such solution have no injurious action on the fibres and that by using the separate
heater for the solution without the injection of live steam, the dilution of the
solution by water of condensation is avoided and it is unnecessary to subject the
fibre to a solution of excessive strength in order to compensate for this dilution.
When completed, the solution is drawn off and the fibres are washed by the
circulation through the digester of plain hot water or of cold water heated by the
injection of steam.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is:-
-
1. The herein described method of removing gummy and other mattera from
China grass and other vegetable textile fibres, which consists in subjecting the
fibres to the action of a heated solvent solution prepared of the ingredients and in
the manner first above described the operation being performed under steam
pressure in a digester substantially as specified.
2. The herein described method of completing the degumming of, and of remov-
ing the bark from, China grass and other vegetable textile fibres, which consists in
subjecting the fibres to a hot solution of caustic soda and carbonate of soila under
steam pressure as specified.
3. The combined process of degumining China grass and other vegetable textile
fibres and of removing the bark, which consists in first subjecting the fibres to a
hot solvent solution prepared as first herein described and afterwards to a second
solution prepared as last herein described, both operations being performed by
causing the solutions to circulate through the fibres under steam pressure as herein
set forth.
T
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