A New or Improved Process of Obtaining and Bleaching Vegetable Fibres.
Year: 1890

page_text: Date of Application, 13th Aug., 1890-Accepted, 13th Sept., 1890
A New or Improved Process of Obtaining and Bleaching Vegetable
Fibres.
We, KONRAD TROBACH of Berlin and GEORG JULIUS BRUCK, of Leipzig German
Empire, 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 :-
According to the process hitherto used textile fibres, particularly flax fibres, are
freed from the incrusting substances (such as pectine, gum bodies, groasy substances
and the like); by rotting and retting the plants.
This tedious process has two great disadvantages.
Firstly the rotting and retting do not separate all the incrusting substances from
the fibre, in particular the greasy substances are not separated, and certain rotting
products remain adhering to the fibre rendering the latter brittle and destroying the
silky gloss naturally proper to the fibre.
These rotting products render the bleaching of the yarns and fabrics more difficult;
the duration of the chlorine bleaching is increased by their presence and the fibre is
thereby injured.
The second disadvantage is occasioned by the difficulty of preventing the fibre from
being injured and destroyed by being retted too long.
These disadvantages are obviated by the hereinafter described process which
moreover affords the additional advantage of effecting the perfect bleaching of the
vegetable fibre, so that the bleaching of the grey yarns and fabrics, which has been
hitherto necessary, is dispensed with. According to this invention the ripe dry
vegetable fibres are boiled in soap solution; by this means the greasy substances, the
pectine and gum matters, swell up and become gelatinous, and the fibre is loosened
from the cortex or straw.
The soap solution which may be used for several boilings, is then let off and for it
there is substituted clean hot water. After by boiling with the latter the remains of
the soap have been removed, cold water is added and a further washing and cooling
take place.
The material so prepared is then introduced into a solution of permanganate of
potassium or of sodium, by which means the pectine, gum and colouring matters are
completely oxidised and destroyed. The quick decomposition of these matters is
facilitated by the previous boiling in soap solution.
After the solution of permanganate of potassium or of sodium has been drawn off,
the material is washed in cold water. The plants are now covered with a reddish
brown deposit, but they are otherwise absolutely free from organic incrusting
substances.
In order to destroy this manganese deposit the material is placed into a bath of
sulphurous acid dissolved in water; after having been acted upon by the latter bath
for a short time the material is washed in a cold condition, and it then consists only of
the straw by which the fibre free from any incrusting substances is loosely carried.
After the straw has been dried, it is broken in the usual manner and separated by
swinging and heckling. The pure fibre when spun gives a silky glossy yarn which is
of greater strength than that produced by the hitherto known methods.
The heckled entangled parts of the fibre are carded (after the manner of cotton
spinning) so as to forin an extremely soft white lap and are then spun.
By the above described method not only are better, lenger, more pliant and
brilliantly white bleached fibres produced, but the process may also be carried out in a
considerably shorter time than is occupied by the hitherto known processes of
separating and bleaching vegetable fibres."

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 we declare that what we
claim is :-
The process of producing from ripe dry fibre plants pliant and brilliantly white
vegetable fibres capable of being spun by boiling such plants in soap solution thereby
separating the greasy substances of the plants and dissolving the incrusting pectine,
gum and colouring matters, then destroying the incrusting substances by oxydation
by treating them with permanganate of potassium or of sodium and removing the
deposits of manganese formed upon the vegetable fibre by washing the latter in a bath
of aqueous acid substantially as set forth.
Duted this 13th day of August 1800
K. TROBACH,
Per L. W.
G. J. BRUCK,
Per L. W.