AN IMPROVED METHOD OR PROCESS FOR PRODUCING PAPER MAKERS' PULP FROM CANE, BAMBOO, AND OTHER ANALOGOUS SUBSTANCES
Year: 1865

page_text: PROVISIONAL SPECIFICATION left by William Robert Lake at the Office
of the Commissioners of Patents, with his Petition, on the 18th Novem-
ber 1865. A communication from abroad by Charles Heaton, of the
City, County, and State of New York, United States of America.
I, WILLIAM ROBERT LAKE, of the "International Patent Office," No. 8,
Southampton Buildings, Chancery Lane, in the County of Middlesex, Con-
sulting Engineer, do hereby declare the nature of the said Invention for
"AN IMPROVED METHOD OR PROCESS FOR PRODUCING PAPER MAKERS' PULP FROM
CANE, BAMBOO, AND OTHER ANALOGOUS SUBSTANCES," a communication, to be as
follows:-
The said Invention consists in first separating the gummy portions of cane,
bamboo, and analogous substances from the fibrous portions of the same
by mechanical or other suitable means, and then converting the fibrous por-
tions into paper pulp by the use of alkaline and bleaching solutions. By the
process formerly adopted for converting these substances into pulp they are
boiled in some kind of alkaline solution of considerable strength under pres-
The effect of this treatment upon the fibres is very injurious, for the
reason that the gums of cane and bamboo contain the coloring properties of
these plants, and the said gums will neutralize or destroy any alkali of a
strength not greater than six degrees Beaumé. When, therefore, any alkali
of less than six degrees Beaumé is applied to cane or bamboo while the gums
are present in the said plants the said alkali is neutralized, and forms with the

page_text: gum a dark-colored compound which is neither acid nor alkali. By the
application of heat this neutral compound becomes a powerful dye, and is so
strongly boiled or set into the fibres that the color. imparted to the said fibres
can only be removed therefrom by a powerful and long continued process of
bleaching. This severe bleaching seriously impairs the strength of the fibres,
is very costly, and frequently fails to produce the degree of whiteness required
for the manufacture of the finer qualities of pulp.
My Invention is intended to remedy this defective and expensive method of
treatment, and is based upon the fact which I have discovered, that if the
gums of the cane, bamboo, or other similar substance are removed previous
to treating the materials with the alkaline solution, the formation of the dye
described, and consequently the boiling in of the coloring matter, is prevented.
Hence comparatively little subsequent bleaching is required, and a weak
bleaching solution applied for a short time will render the fibres beautifully
white without impairing their strength. Before separating the gums the crude
material (after being cut into convenient lengths) is advantageously treated
for about seven days with a weak solution of caustic soda or other suitable
alkali of about two degrees Beaumé, contained in a vessel of the ordinary con-
struction for such purposes heated by a steam coil or other convenient
apparatus. This treatment softens the material and renders the separation of
the gums much more easy, rapid, and complete. This softened material is
then thoroughly pressed by being passed through rolls; these rolls are similar
to those commonly used in paper mills for pressing cane and bamboo, but are
arranged to work somewhat nearer together in order to produce a greater
pressure upon the materials. By means of these rolls the cane or other sub-
stance will be pressed perfectly flat, and the gummy portions thereof will be
in a pithy or almost frothy condition and in layers parallel with the fibres.
These flat layers are then run through a beater of the ordinary kind used in
paper mills to separate and wash out the gummy portions, water being used
in the ordinary manner. This operation entirely removes the gums and
reduces the fibres to a pulpy condition in a very superior manner.
The pulp
is then subjected to a bleaching solution of a strength of about two degrees
Beaumé, which will impart a beautiful whiteness to the said pulp. If a fine
grade of paper is desired, the pulp is then boiled in an alkaline solution of a
strength of about two degrees Beaumé, in order still further to soften the said
pulp, the time of boiling being from one to four hours according to the pur-
for which the paper is required. The pulp is then carried directly into
the grinding machine and is thence run into the paper engine to be manufac-
tured into strips or sheets in the usual manner. When a common grade of
pose

page_text: paper is being made, the last softening process may be dispensed with and the
pulp taken direct to the grinding engine.
By my improved process of manufacturing pulp from cane or bamboo much
less time is required than in any other process, the cost is greatly diminished,
and a close, even, and exceedingly fine texture is imparted to the paper.
Although described as more especially applicable to cane and bamboo, my
process may be applied to the treatment of wood, straw, and other similar
substances.