An Improved Material suitable for‘Engine Packing, the Manufacture of Dynamite and other purposes, and Methods of Preparing and Treating same.
Year: 1899

page_text: Date of Application, 28th Mar., 1899-Accepted, 1st July, 1899
An Improved Material suitable for‘Engine Packing, the Manufacture
of Dynamite and other purposes, and Methods of Preparing and
Treating same.
A communication from abroad by THE MARSDEN COMPANY, a Corporation under
the laws of the State of New Jersey, U.S.A., and having an office at
No. 850, Drexel Building, corner of Fifth and Chestnut Streets, Phila-
delphia, Pennsylvania, U.S.A.
-
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, in the County of
Middlesex, Fellow of the Chartered Institute of Patent Agents, 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:-
Raw pith as it is found in its natural state consists of a cellular structure, the
cells of which either contain sap. or dried or partially dried sap, and with which
are combined certain adherent matters, the precise character of which is not
known.
Raw pith such as the pith of maize or cornstalk when compressed has a capacity
to absorb many times its volume of liquid, and leak-protectors for vessels have
been made consisting of a filler composed essentially of such compressed and
comminuted cornstalk pith. An attempt to make use of it for other purposes
showed that in its natural condition it was not suitable therefor. Thus in
attempting to nitrate the pith it was found that the sap and other matters con-
tained in the cells and adherent to the natural pith resulted in a violent reaction,
increased temperature, partial destruction of the cellular structure, imperfect
nitration of the residue and in the production of chemical compounds which
contaminated the product attempted to be made. In some cases the interior
portions of the pith were not reached or affected by the acid, and attempts to
remove the deleterious materials or the acid used in nitrating by means of wash-
ing and drying proved to be ineffective.
This invention is based on the discovery that it is possible to eliminate these
objectionable characteristics and to effect profound chemical changes in the
pith and to produce a practically new article therefrom, by first separating the
pith from the woody shell or outer fibrous portion of the stalk, then heating and
breaking up the pith (in some instances comminuting it until the particles are
about the size of grains of rice) and in subjecting the pith to the action of a
blast or current of air, preferably heated.
The pith is broken up preferably by percussive action, and the matter which
has been deposited within the cells and changed by the heat is thereby loosened,
so that the subsequent air blast can readily remove the same; and in practice the
pith is submitted to repeated heating, beating, and washing with air blasts until
Di Q77

page_text: "
the desired result is secured. The higher the temperature to which the pith is
subjected the better, but care must be taken to prevent its ignition. The heating
if desired may accompany the comminuting process.
This treatment of the pith results in causing the solid constituents of the sap
to be separated out therefrom in the form of films extending between or coating
the cell walls of the pith; the comminuting of the pith exposes and opens the said
cells, the heat causing the pith to fracture rather than solidify, which is the case
when the pith is broken up in a wet state, and the air currents tend further to
dry the liquid constituents of any sap contained in the cells, and further to expel
therefrom the filamentary portions separated from the sappy matters by the
heating of the same, and also to remove from association with the cellular
structure the other particles of deleterious matters before referred to.
Further, the new product has different chemical characteristics from those of
the dried natural pith, compressed or not. These chemical changes are indicated
by the slower reaction changes which take place with reagents, and are demon-
strated by the fact that the new pith is firmer and tougher than the natural
pith, does not become brittle by lapse of time and is less liable to break in cutting
into sections, and that the chemical constituents of the new pith and the natural
pith, where they exist in each, exist in very different proportions--as, for
instance, 7.08 of glucose in the new article and 3.55 in the natural pith; glucose
vielding bodies calculated as starch 6.337 in the new article and 3.20 in the
natural pith, and with nearly four per cent. additional carbon in the new article
over that in the old.
It is further found that the new article and the natural pith respond very
differently to the action of different reagents.
The only characteristics so far known of natural compressed pith is the
capacity to absorb large proportions of liquid, and it has been found that if the
pith instead of being merely broken up. dried and compressed (which was all that
was comprised in the former process of treatment) is subjected to the operations
above described, so as to produce the novel article referred to, this article if
dried and compressed will absorb fully thirty-five per cent. more of water under
similar conditions.
While, for comparison, reference is made to the use of the compressed material
as absorbing water, it may be used in any case where it is desirable that the
material should take up a large body of liquid.
Thus the prepared pith is specially applicable for use as a vehicle for carrying
liquids, for instance, for carrying oil for use in journal boxes, or as an absorbant
for nitro-glycerine in dynamite. In such cases, it is required to uniformly charge
the pith with liquid, yet not to saturate it, as the liquid would escape too readily
under pressure or the weight of the material. The pith is first fully saturated
with the liquid and then enough of the latter removed to leave the proper pro-
portion in the pith. One way is to saturate the pith with oil or nitroglycerine
and then remove the surplus by pressure. Another way is to make a weak
solution of the liquid in a volatile solvent and then evaporate and recover the
latter. Thus nitroglycerine may be dissolved in petroleum ether, the pith
saturated with the solution and then heated at a low temperature until the
ether is volatilized, leaving only the nitroglycerine in the pith.
Pith thus supports a large percentage of liquid and serves admirably for
transportation, as the liquid will not be lost if the vessels leak. It serves to
feed oil to journals if the material is packed in the journal box, while in the
case of nitro-glycerine, the pith disappears in the explosion without ash or
material residue.
While reference is made to these as instances of the effective application of
the improved material, it may be used for many other purposes; for instance,
because of its purity and capacity to respond readily to the action of reagents,
for the manufacture of viscose, and because of its purity and its capacity to be

page_text: thoroughly and uniformly nitrated, for use in the manufacture of those sub-
stances in which nitrated cellulose must be employed.
Having now particularly described and ascertained the nature of said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent I declare that what I claim is;-
-
1. The within-described new material adapted for use for packings and other
purposes, the same consisting of the comminuted cellular portion of vegetable
pith freed from sappy deleterious and adherent matters and having the
characteristics substantially as set forth.
2. The method of preparing a material from vegetable pith consisting in
separating it from the woody and fibrous portions of the shell, and then com-
minuting the pith and subjecting it to heat and air blasts, substantially as set
forth.
3. As a new manufacture, a mass of vegetable pith comminuted and uniformly
charged with a limited proportion of liquid, substantially as described.
4. The mode of charging pith uniformly with limited proportions of liquid,
consisting in first fully saturating the pith and then removing a part of the
liquid substantially as described.