Improvements in Moulding Compounds for Foundry Purposes.
Year: 1893

page_text: Date of Application, 20th June, 1893-Accented, 22nd July, 1893
COMPLETE SPECIFICATION.
Improvements in Moulding Compounds for Foundry Purposes.
I, JOHN ROWBOTIAM, a citizen of the United States residing at Merchantville,
in the County of Camden, and State of New Jersey, Chemist, do hereby declare
the nature of my invention for IMPROVEMENTS IN MOULDING COMPOUNDS, and in
what manner the same is to be performed to be particularly described and
ascertained in and by the following statement :-
My invention has relation to the production of a compound for use in moulding
operations.
The principal objects of my invention are first, to provide an inexpensive and
efficient neutral or substantially neutral.compound for employment in moulding or
other similar operations; and second, to provide a compound for use in moulding
operations in a neutral or substantially neutral state or condition in contradistinction
to an acid or alkaline state or condition and one that will not sour, ferment or
otherwise deteriorate by age and that can be economically employed, due to the
fact that waste is reduced in its use in moulding operations to a minimum.
My invention consists of a compound composed of rosin, an alkali and a binder
or body-material, as saw-dust, ground cork, bark, chaff, nut-hulls or other analogous
vegetable material or materials; and
My invention further consists of a compound for use in moulding operations
composed of rosin, caustic-soda and saw-dust or analogous material.
In order to enable others to understand my invention I will now proceed to
describe a method of producing such a compound.
Rosin of commerce is introduced into an alkaline solution, as caustic-soda or like
material and a binder or body-material, as saw-dust, ground cork, bark, chaff
nut-hulls or analogous vegetable material or materials added thereto. The alkali,
for example, the caustic soda is dissolved in the quantity of water required for the
production of the compound or mass and heated or boiled over a furnace or by
means of a steam coil for a period of time ranging from (1) to two (2) hours,
more or less, and during this operation the rosin is added and kept agitated until
it is thoroughly dissolved. The hot liquid compound is then removed and a
binder or body-material, as saw-dust, chaff, bark, ground cork, ground-shells,
nut-hulls or other vegetable material or materials mixed therewith." In practice
good results have been obtained by adding to every fifty (50) gallons of the
compound from twelve (12) to twenty-five (25) gallons of the binder or body-
material that is, saw-dust, bark, ground-cork, chaff, ground shells, nut-hulls or
other vegetable material or materials. In the production of the compound
excellent results have been obtained by mixing with ten parts of rosin one
and one-tenth (11) parts of caustic-soda, more or less. Moreover, in the use
of the caustic-soda there is a thorough admixture, as well as a thorough
chemical combination of the respective materials with each other in the
compound in a viscous or semi-fluid state or condition, which can be readily
demonstrated by testing the same in any preferred manner. Moreover, by persuing
the above prescribed course the compound is produced in a neutral or substantially
neutral state or condition, because the alkali is thoroughly taken up or neutralized
by the rosin therein. Preference is given to the use of caustic-soda with the
rosin of commerce for the composition of the compound, because the viscous or
liquid mass is obtained without having to skim or siphon off the same in the
containing vessel. If any other alkali is employed after boiling the described
materials of the compound together, they separate while cooling, and this
separating and settling of the two materials in the containing vessel occurs, it has
been found in practice, even when great care is exercised in the manufacture

page_text: thereof. Moreover, that a light coloured semi-liquid resinous mass settles in the
bottom of the containing vessel and a portion of the alkaline solution floats
on the surface, so that it becomes necessary in order to remove the same to siphon
it off to prevent the precipitate from again separating and of assuming both thick
and thin conditions in the containing vessel and necessitating a re-feating of the
mass to overcome such separation and settling of the mass. By proceeding in the
manufacture of the compound in the manner described, and employing caustic-soda
with rosin in about the proportions stated, a most excellent neutral or substantially
neutral compound is obtained, which with the addition of the binder or body
material, as saw-dust, ground cork, chaff or other vegetable matter or materials
gives a most excellent glutinous product for cores or use in moulding operations,
because it has been found in practice that cores treated with this liquid or
semi-liquid compound are far less brittle when dried and that far less dense smoke
and offensive odours are given off in the pouring of the molten metal. In moulding
operations the offensive odours and dense clouds of smoke given off have been
looked upon for a long time as features to be avoided, but moulders have been
without the means or materials at their command to effect such a result. In the
use of this liquid or semi-liquid compound in such operations the pungent odours
and dense and likewise offensive smoke given off are reduced to a minimum.
The described compound is used in connection with cores in moulding and foundry
work by mixing this liquid or semi-liquid compound thoroughly with the sand of
the cores and in the production of large cores, it has been found advantageous to
apply directly to the cores in any convenient manner this liquid or semi-liquid
compound containing saw-dust or analogous material in addition to mixing the
same with the sand thereof, which teads not only to strengthen thein, but also to
facilitate removal of the cores after the casting operation has been completed.
This is due to the fact, that the binder or body-material of this liquid or semi-
liquid compound will readily burn under the influence of the heat of the metal,
thereby leaving the cores not only in a loose condition, but permitting of their
ready removal and to compensate for any yielding or shrinkage of the metal while
cooling, without straining the same. In practice the important function of the
binder or body-material in the compound in moulding operations is to keep the
sand of the moulds porous or loose and thus to facilitate the escape of air and
gases as well as to lessen liability to blowing and all difficulty of removing the
casting. Moreover, such liquid or semi-liquid compound being produced in a
neutral or substantially neutral state, that is, neither acid or alkaline, will not sour,
ferment or deteriorate by standing or age.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is :-
1. A neutral or substantially neutral compound, composed of an alkaline resinate
and a binder or budy-material, substantially as described.
2. A neutral or substantially neutral liquid or semi-liquid core compound,
composed of rosin, caustic-seda and saw-dust or analogous material, substantially
as described.
Dated this 25th day of May A.D. 1893.
JOHN ROWBOTHAM.
W. P. Thompson & Boult,
Agents for the Applicant.