Improvements in the Manufacture of Nitrocellulose and Apparatus for that Purpose.
Year: 1890

page_text: Date of Application, 8th Apr., 1890 ·
Complete Specification Left, 29th May, 1890-Accepted, 5th July, 1890
PROVISIONAL SPECIFICATION.
* Improvements in the Manufacture of Nitrocellulose and Apparatus
for that Purpose.
'1, JOSEPH RICHARD FRANCE of Plainfield, County of Union and State of New
Jersey United States of America Manufacturer do hereby declare the nature of this
invention to be as follows :—
Nitrocellulose is usually manufactured by subjecting to the action of nitric and
sulphuric acids, cotton or like material in its fibrous condition, or, sometimes, after it
has been spun or woven, or pulped and made into paper. The action of the acids on
the material in these conditions is comparatively slow and often irregular, and the
process must be carefully watched and carried on at stated temperatures, requiring
that the nitrating apparatns must be warmed in winter and cooled in summer.
This
invention relates to means of nitrating cellulose in a short time and with great
regularity, notwithstanding considerable variations of temperature, and without
requiring much care or attention on the part of the operator.
For this purpose, the cotton or other fibre, preferably in its natural state, but it may bo
after roving or loose twisting, well cleaned from impurities, is ground or is cut into
very short lengths so as to form virtually a powder, in which condition it is subjected
to the action of the acids, applied in the usual proportions for producing either the
soluble or the insoluble kinds of nitrocellulose, and, after being well washed with
water so as to remove acid residues, it is ready for use in the form of a pulp, or it may
be dried to the condition of a powder. A convenient machine for comminuting the
fibres is of the following description. It consists of a pair of feeding rollers moved
step by step by ratchet gear, a pair of clamps alternately opened and closed by eccen-
trics or cams, and a set of knives set helically around a revolving shaft. Sliver froni
a carding machine, being introduced, between the feed rollers, is by them advanced a
short distance between and beyond the jaws of the clamp, which are then open. The
feed rollers then resting, the clamps close on the sliver holding it tightly, and the
revolving knives cnt off the short lengths of fibres projecting beyond the clamp.
Dated this 8th day of Anvil 1800.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Nitrocellulose and Apparatus
for that Purpose.
I, JOSEPH RICHARD FRANCE, of Plainfield County of Union and State of New
Jersey, United States of America, Manufacturer, 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 :-
Nitrocellulose is usually manufactured by subjecting to the action of nitric and
sulphuric acids, cotton or like material in its fibrous condition, or, sometimes, after it
has been spun or woven, or pulped and made into paper. The action of the acids on
the material in these conditions is comparatively. slow and often irregular, and the
process must be carefully watched and carried on at stated temperatures requiring that
the nitrating apparatus must be warmed in winter and cooled in summer. This
invention relates to means of nitrating cellulose in a short time and with great
regularity, notwithstanding considerable variations of temperature, and without
requiring much care or attention on the part of the operator.
For this purpose, the cotton or other fibre, preferably in its natural state, but it may
Price d71

page_text: be after roving or loose twisting, well cleaned from impurities, is ground or is cut into
very short lengths so as to form virtually a powder, in which condition it is subjected
to the action of the acids, applied in the usual proportions, for producing either the
soluble or the insoluble kinds of nitrocellulose, and, after being well washed with
water so as to remove acid residues, it is ready for use in the form of a pulp, or it may
be dried to the condition of a powder.
For nitrating the cotton powder in order to produce soluble nitrocellulose, about
parts nitric acid at 42° Baumé and about 12 parts sulphuric acid at 66° Beaumé
form a suitable mixture, in which the cotton dust should be stirred for about a quarter
After soaking, the
"of an hour under temperatures varying from 50° to 100° Fahr.
surplus of acid is pressed out, and the product is washed repeatedly until it is entirely
freed from acid.
For nitrating to produce insoluble or highly explosive nitrocellulose, the acid
mixture should consist of about 7 parts of strong nitric acid as free from water as can
be obtained, and of about 21 parts of sulphuric acid of 661° Beaumé, the treatment
being otherwise the same as that for soluble nitrocellulose.
For the purpose of comminuting the cotton I prefer to employ a machine such as is
represented in the accompanying drawings.
Figs. 1 and 2 are views of opposite ends, Fig. 3 is a back view with parts removed
to shew parts beyond.
The sliver of carded cotton is carried by the endless apron N between a pair of feed
rollers R R¹, which may be fluted, and is passed over the straight edge of a knife K on
which it is clamped by a clamp C while the revolving knives K', shear off the fibres
projecting beyond the knife K.
Between the passage of one knife K¹ and the next, the cotton is advanced by a step,
which may be about 3d of an inch.
W is the knife wheel, which, as shewn carries four helically shaped knives K³, and
is driven through a toothed wheel G on its axis gearing with a pinion on the shaft S₁!
of the driving pulley P. On this shaft is an eccentric E linked to one arm A of a
bell crank the other arm A' of which moves the vibrating cams C¹ and clamp heads H
thus lowering the clamp C. A crank pin on the bell crank shaft also moves the
pawls P P giving step by step motion to the ratchet wheel R" on the shaft of the
feed roller R which is geared to the shaft of R. The cams (are pivotted on vertical
rods Se surrounded by springs which raise the clamp C during each forward step of
the sliver. Between the clamp C and the head H is interposed an elastic packing E'
to allow for variations in the thickness of the sliver. The clamp head H moves in
curved guides H' concentric with the knife wheel W. The frame carrying the knife K
is pivotted at P1 and has arms A", indicated by dotted lines in Fig. 2, secured by
setting screws S S₁ (Fig. 3) by which the knife K can be adjusted for wear. The
bearings of the feed roller R are pressed by springs so as to allow for irregularities of
the sliver that passes between the rollers.
Having now particularly described and ascertained the nature of this invention and
in what manner the same is to be performed, I declare that what I claim is :-
1. The herein described process for manufacturing nitro cellulose by comminuting
cotton or reducing it to a uniform dust like condition, subjecting it to the action-of-a
suitable mixture of nitric and sulphuric acids, pressing out surplus of acid and
thoroughly washing the product.
2. As an improved article of manufacture, nitrocellulose produced by treatment of
cotton by the above process.
3. Apparatus for comminuting cotton, substantially as described with reference to
the accompanying drawings.
Dated this 29th day of May 1890..
ADEL & MRAT,
Agents for the Applicant.