By Messrs. LEYKAM and TOSEFOTHAL.
Jute is well known as a very cheap fiber, and its employment in
textile industry is consequently both extensive and always increasing.
Accompanying this increase is a corresponding one in the amount of old
waste jute, which can be employed for the manufacture of paper.
Up to the present time, only very little use has been made of jute for
the manufacture of thread and the finer fabrics, because the
difficulty of bleaching the fiber satisfactorily has proved a very
serious hindrance to its improvement by chemical means. All the
methods hitherto proposed for bleaching jute are so costly that they
can scarcely be made to pay; and, moreover, in many cases, the jute is
scarcely bleached, and loses considerably in firmness and weight,
owing to the large quantities of bleaching agents which have to be
applied.
In consequence of this difficulty, the enormous quantities of jute
scraps, which are always available, are utilized in paper making
almost entirely for the production of ordinary wrapping paper, which
is, at the best, of medium quality. In the well known work of Hoffmann
and Muller, the authors refer to the great difficulty of bleaching
jute, and therefore recommend that it be not used for making white
papers.
Messrs. Leykam and Tosefothal have succeeded in bleaching it, and
rendering the fiber perfectly white, by a new process, simple and
cheap (which we describe below), so that their method can be very
advantageously employed in the paper industry.
The jute fiber only loses very little of its original firmness and
weight; but, on the other hand, gains largely in pliability and
elasticity, so that the paper made from it is of great strength, and
not only resists tearing, but especially crumpling and breaking.
The jute may be submitted to the process in any form whatever, either
crude, in scraps, or as thread or tissue.
The material to be bleached is first treated with gaseous chlorine or
chlorine water, in order to attack the jute pigment, which is very
difficult to bleach, until it takes an orange shade. After having
removed the acids, etc., formed by this treatment, the jute is placed
in a weak alkaline bath, cold or hot, of caustic soda, caustic potash,
caustic ammonia, quicklime, sodium or potassium carbonate, etc., or a
mixture of several of these substances, which converts the greatest
part of the jute pigment, already altered by the chlorine, into a form
easily soluble in water, so that the pigment can be readily removed by
a washing with water. After this washing the jute can be bleached as
easily as any other vegetable fiber in the ordinary manner, by means
of bleaching powder, etc., and an excellent fibrous material is
obtained, which can be made use of with advantage in the textile and
paper industries.
The application of the process may be illustrated by an example:
One hundred kilos. of waste jute scraps are first of all treated in
the manner usually employed in the paper industry; 15 per cent. of
quicklime is added, and they are treated for 10 hours at a pressure of
1½ atmospheres. The scraps are then freed from water by means of a
hydro-extractor, or a press, and finally saturated with chlorine in a
gas chamber for 24 hours or less, according to the requirements of the
case. Every 100 kilos. of jute requires 75 kilos. of hydrochloric acid
(20° B.) and 20 kilos. of manganese peroxide (78-80 per cent.).
The jute then takes an orange color, and is subsequently washed in a
tank, a kilo. of caustic soda being added per 100 kilos. of jute; this
amount of alkali is sufficient to dissolve the pigment, which colors
the water flowing from the washer a deep brown. After washing, the
jute can be completely bleached by the use of 5-7 kilos. of bleaching
powder per 100 kilos. of jute.--_Mon. de la Teinture_.
* * * * *
THE INDEPENDENT--STORAGE OR PRIMARY BATTERY--SYSTEM OF ELECTRIC MOTIVE
POWER.[1]
[Footnote 1: Abstract of a paper read before the American Streel
Railway Association, Oct. 23, 1891.]
By KNIGHT NEFTEL.
Owing to a variety of causes, the system which was assigned to me at
the last convention to report on has made less material progress in a
commercial way than its competitors.