IMPROVEMENTS IN THE TREATMENT OF LINEN AND OTHER FIBRE FOR INCREASING THE FINENESS, LUSTRE AND SOFTNESS THEREOF A commu- nic
Year: 1882

page_text: LETTERS PATENT to Friedrich Carl Glaser of Berlin in the Kingdom of Prussia
and empire of Germany, Engineer and Patent Solicitor for an invention of
"IMPROVEMENTS IN THE TREATMENT OF LINEN AND OTHER FIBRE FOR
INCREASING THE FINENESS, LUSTRE AND SOFTNESS THEREOF
A commu-
nication by Heinrich Knab of Münchberg in the Kingdom of Bavaria
"
PROVISIONAL SPECIFICATION left by the said Friedrich Carl Glaser at the
Office of the Commissioners of Patents on the 16th May 1882.
FRIEDRICH CARL GLASER of Berlin in the Kingdom of Prussia and Empire of
Germany, Engineer and Patent Solicitor "IMPROVEMENTS IN THE TREATMENT OF
LINEN AND OTHER FIBRE FOR INCREASING THE FINENESS, LUSTRE AND SOFTNESS
"
THEREOF [A communication by Heinrich Knab of Münchberg in the Kingdom
of Bavaria.]
The fibres of flax, hemp, jute, China grass, nettles and other plants as obtained
by the ordinary processes possess, as compared with silk, great hardness and want
of finess and require a long and expensive bleaching process. In particular, linen
fibre cannot be brought to anything like its full value on account of the presence
of cementitious matter and other impurities which prevent its being subdivided to
a sufficient degree of fineness to produce fabrics of fine texture, lustre and softness,
similar to that which silk is capable of assuming.
The present invention has for its object to obviate these disadvantages by
subjecting the fibre to processes whereby it can be subdivided about 50 times the
degree of finess which it now possesses, and which enables it to be brought to the
requisite degree of purity by means of a very weak artificial bleaching process.
The invention consists mainly in the consecutive treatment of the fibre whether
in the unspun or the spun condition, with concentrated alkaline lyes and with soap
solutions or saponified oils and fats.
The process is as follows: The linen or other fibre is first treated with com-
paratively strong alkaline lye, by boiling either at atmospheric or higher pressure.
By this means a large proportion of the impurities are dissolved and removed, and

page_text: the fibre becomes more lustrous, softer and capable of finer division. The fibre_is
then again boiled in comparatively strong solutions of soap or saponified oils. By
this operation all wood particles are completely removed from the fibre, which is
thus rendered perfectly pure, assuming a silk like lustre and softness and being
capable of great subdivision as aforesaid.
Lastly the fibre or the thread or fabric made therefrom is bleached in a very
weak lye of chloride of soda, or hyposulphite of soda and the like, the perfect
bleaching of the fibre by this means, without the use of air bleaching being
rendered possible without detriment thereto on account of its perfect freedom from
impurities.
The fibre thus obtained can be easily dyed and assumes all the appearance
of silk.
The degree of concentration of the alkaline lyes depends upon the nature of the
raw fibre to be treated; generally a solution of alkali, such as caustic soda of
100° to the extent of 4 per cent of the weight of the fibre to be treated has been
found to answer best. For the soap solutions from 10 to 15 per cent of ordinary
oil soap may be used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Friedrich Carl Glaser in the Great Seal Patent Office on the
8th November 1882.
FRIEDRICH CARL GLASER of Berlin in the Kingdom of Prussia and Empire of
Germany, Engineer and Patent Solicitor.-"IMPROVEMENTS IN THE TREATMENT OF
LINEN AND OTHER FIBRE FOR INCREASING THE FINENESS, LUSTRE AND SOFTNESS
THEREOF A communication by Heinrich Knab of Münchberg in the.kingdom of
Bavaria
The fibres obtained from the flax and hemp plants by the usual processes show
not only great hardness, but are also capable of only slight subdivision, and the
bleaching of the threads or fabrics prepared therefrom requires to be effected either
by a long and expensive air bleaching process or by treatment with chlorine of such
strength as to act more or less injuriously on the fibre
The actual value possessed by these fibres has not up to the present time been
nearly ascertained, because they have been employed in a comparatively raw
condition combined with impurities such as rind and woody particles, and it was
consequently very difficult to spin, a really fine thread therefrom, which should
enable the fabrics prepared from them to resemble silk in softness, fineness and
lustre, while at the same time they would have the advantage of being washable,
and consequently of much more extended application
The present invention has for its object to obviate these disadvantages by
subjecting the flax and hemp fibres to processes whereby they can be subdivided
to about fifty times the degree of fineness which they now possess and which
enable them to be brought to the requisite degree of purity by means of a very
weak artificial bleaching process
The invention consists mainly in the consecutive treatment of the fibre whether
in the unspun or the spun condition, with alkaline lyes and with soap solutions or
saponified oils and fats.
The process is as follows:-The linen or flax fibre is first treated in the unspun
condition with comparatively strong alkaline lye, by boiling at high pressure. By
employing high pressure, the operation can be carried out with a very small
expenditure of time, while the use of a lower pressure entails a corresponding
longer duration of the process. With a pressure of two atmospheres the boiling
has been completed in about four hours. By this means a large proportion of the
impurities is dissolved and removed and the fibre becomes more lustrous, softer,
and capable of finer division. The fibre is then again boiled in comparatively
strong solutions of soap or saponified oils. By this means all woody particles are
completely removed from the fibre, which is thus rendered perfectly pure, assuming
a silk like lustre and softness and being capable of great subdivision as aforesaid.
Lastly the fibre or the thread or fabric made therefrom may be bleached in a
very weak lye of chloride of soda and the like, the perfect bleaching of the fibre by
this means without detriment and without the use of air bleaching being rendered
possible without detriment thereto on account of its perfect freedom from
impurities. After each operation the fibres are rinsed in pure water and they
are finally freed from the greater part of their moisture by pressing or in
centrifugal machines, and are then dried
The fibre thus obtained can be easily dyed and assumes the appearance of silk.
The degree of concentration of the alkaline lyes depends upon the nature of the
raw fibre to be treated; generally a solution of alkali, such as caustic soda, of
100° to the extent of 4 per cent of the weight of the fibre to be treated has been

page_text: found to answer best. For the soap solutions from 10 to 15 per cent of ordinary
oil soap may be used.
The fibres prepared as above described shew, after weaving, the above described
property in being bleached, namely, that a weak chlorine solution is sufficient to
obtain a perfectly white colour, so that the fabric thus prepared will be much
stronger than fabric treated with strong bleaching liquids such as have been used
before.
Having thus described the nature of the said invention and in what manner the
same is to be performed, as communicated to my by my correspondent, I claim,
The herein described method of treating flax and hemp fibres by boiling them
under high pressure with alkaline lyes, and afterwards treating them with soap
solutions or saponified oils or fats, whereby the fibres obtain a fine state of
subdivision, combined with increased lustre and softness, rendering them similar
to silk
In witness whereof, I, the said Friedrich Carl Glaser, have hereunto set my
hand and seal this sixth day of November, in the year of our Lord, One
[sic] thousand, eight hundred and
FRIEDRICH CARL GLASER (L.S.)