Improvements in Treating Bast and Wood for Obtaining therefrom Fibre suitable for being Spun or Woven.
Year: 1893

page_text: Date of Application, 10th Feb., 1893-Accepted, 11th Mar., 1893
COMPLETE SPECIFICATION.
Improvements in Treating Bast and Wood for Obtaining therefrom
Fibre suitable for being Spun or Woven.
I, ADOLF TÖRNGREN, formerly Spinning Mill Owner, of Tammerfors, Finland,
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 the manufacture of a fibre capable of being spun or
woven from the well known fibrous material bast, which lies between the wood and
the bark of trees and envelopes the latter in a ringlike manner.
The characteristic of the new process consists in the fact that, conversely to the
method employed in making cellulose, the bast is first deprived of its phosphoric
acid constituents, then of its sulphates, and lastly of its siliceous components, by the
employment of cheap and easily prepared solutions.
The bast, in the condition in which it is found in commerce, is, for the purpose
of manufacturing from it a fibre capable of being spun, first washed in lukewarm
water (which is preferably kept at a temperature below 40° C. so that the
albuminoids are not coagulated) and this washing is carried out by beating the
bast as in the earlier method of washing garments, and is continued until the portions
soluble in water are as completely removed as may be from the bast i.e. until the
washing water runs away clear. The bast so freed from such of its constituents as
are soluble in water, is now brought into a bath of acid (preferably of sulphuric
acid) in order to render the phosphoric acid combinations soluble. The amount of
sulphuric or other acid required varies with the source of origin of the bast, i.e.
according to whether the bast to be treated is that of the lime tree, the aspen, the
willow, or other trees.
In
After the bast has been kept in the acid bath at a temperature below the boiling
point, preferably at from 35° to 40° C. for from four to six hours, it is rinsed and
brought into a bath of common salt, with or without the addition of sal ammoniac,
in order to remove the substances, chiefly the calcium sulphate, with which it is
incrusted. For this purpose about 10% of the weight of the bast in salt is taken.
If sal-ammoniac be used to hasten the process, 1% of the latter will suffice. After
about six hours, during which the temperature is kept constant at 35° C. the salt
solution is run off, and the bast washed and at the same time strongly beaten.
order to render the silicates soluble or to remove them the bast is now brought into
a solution of chloride of lime or other substances yielding chlorine, and is kept in
this chlorine bath at a temperature of preferably 35° C. for from 1 to 2 hours
according to the strength of the solution, and thereafter again washed. If the bast
after being treated as above still contains resin, this last washing is best effected by
the use of a small addition of caustic alkali or soap, with or without the use of
glycerine. In order to complete the removal of the encrusting substances which
may still be present, the bast, after passing through the processes above described
may be put through crushing rollers in the usual way or further treated as in
breaking or heckling flax.
The separation of the fibres of the bast is rendered much easier if the washed
and still wet bast be allowed to become frozen through, and after thawing be
treated as described by means of crushing rollers &c.
The
process described above may be employed with advantage for the preparation
of wood fibre, if the wood be first finely split up and then softened by steam before
treatment.

page_text: 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 :-
In the treatment of bast or wood for obtaining therefrom fibre capable of being
spun or woven.
(1) Removing the phosphoric acid compounds from the bast or wood by
subjecting it to the action of an acid bath, in which it is kept at a constant
temperature (preferably 35° to 40° C.) for from four to six hours, after which it is
washed.
(2) Removing from the bast or wood the encrusting substances especially the
calcic sulphate by keeping it at a constant temperature, (preferably 35° C.) in a
solution of common salt to which if desired an addition of sal ammoniac may be
made, for about six hours, and after running off the solution, washing the bast or
wood, at the same time thoroughly beating it.
(3) Dissolving out and removing the silicates by placing the bast or wood in a
chlorine bath kept at a constant temperature for from 1 to 2 hours according to
the strength of the solution.
(4) In rendering the fibre more pliable, or for removing any resin the bast or
wood may still contain, thoroughly washing it with the addition of a small quantity
of caustic alkali or soap with or without the addition of glycerine, this being
succeeded by further treatment by breaking and heckling, as in the treatment of
flax, if necessary after previous freezing, in the usual way.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.