An Improved Process for the Manufacture of a Compound for use in Making Pottery, Bricks, and the like.
Year: 1898

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by VINCENZO MICHELI, of 10, Piazza Pitti, Florence, in
the Kingdom of Italy, Civil Engineer and Professor at the Academy of Fine Arts,
Florence.]
An Improved Process for the Manufacture of a Compound for use
in Making Pottery, Bricks, and the like.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45, Southampton Buildings, in the County of Middlesex, 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 :-
The object of this invention is to substitute for the terra-cotta which has been used
hitherto in the manufacture of building material, pottery and like wares, a compound
which does not require being burnt or baked after having been moulded and is liable
to undergo no alteration of shape by either deformation or contraction.
The invention mainly consists in first subjecting clays generally, such as
argil (alumina) potters earth (clay loam), the different kinds of marl, sand-stone, kaolin
(porcelain-clay) and the like, including volcanic ashes known as "puzzolana" fossil
earths, boles and the like to a burning or baking process, whenever required and then
moulding them into the desired shapes for use as pottery-ware or building material,
when they may serve as substitutes for iron, wood and stone generally.
The present process of manufacture therefore differs from those which have been
in use hitherto in the particular that according to the old methods the clay or
the like was moulded before it was baked whereas in the process here described the
order of operations is reversed in other words the clays and the like are baked first
and then moulded a change that constitutes a great improvement and offers
considerable advantages, its chief merit being that it enables pottery-ware or
building materials to be turned out regardless of size, which it would be impossible
to do were it necessary to bake the articles after moulding them; for if the
manufacture of large sized articles should be attempted, not only would they be apt
to become deformed, but they would also necessitate the employment of ovens or
kilns of considerable dimensions; it furthermore permits the ingredients which go
to form the paste to be so proportioned as to produce either ordinary or special
materials, being according to circumstances or requirements fire-proof or damp-proof;
or the paste may be made serviceable for coating any articles that it may be desired
to render incombustible, or again, more or less heavy materials may be prepared, say
by means of an admixture of sand, sawdust or the like, and such materials may be
rendered amenable to the laws of statics as applied to the art of building construction,
through the subsidiary employment of metal wood or simply textile material, or
indeed cellulose.
One form in which the process forming the subject of this invention may be carried
out in practice may be described as follows:-
(1) The clays or substances above mentioned are dried; (2) they are powdered to
the desired degree of fineness according to the nature of the goods to be manufactured
(3) they are baked or burnt to the requisite temperature; (4) the various pastes are
then made; and (5) such pastes are moulded either by hand or by machinery into
the shape of the desired articles.
The first of these operations may be performed by various methods either natural or
artificial and may, as required, be either preceded or followed by the second operation.

page_text: As regards the third operation viz.: the baking of the clays or like substances after
allowing them to dry, it may be performed in any suitable ovens or kilns, no matter
how heated.
When the clay has been heated to the temperature necessary to cause it to
contract to the utmost degree it is capable of attaining, it is reduced to powder, unless
that operation has been performed beforehand. When the terra-cotta has been
reduced to dust grains chips or the like, it is kneaded together with amalgamating
substances by means of kneading apparatus suited to such a purpose, say, Boulet's
or Kraatz' machines, and the paste thus obtained is then moulded and compressed
more or less according to requirements and circumstances, either by hand or by
machinery, or drawn out through draw-plates, or sent through machines, to form
either solid or hollow bodies, with or without the insertion of a strengthening
frame work (ribs or stays), as the case may be.
The preparation of the pastes which constitutes one of the main characteristic
features of this invention, after the protective baking and kneading stages consists
in adding amalgamating substances to the terra-cotta powder (or dust), the object of
the addition being to convert the clay into solid and resisting material, among
suitable amalgamating agents may be mentioned lime, cement, ashes, silex, potash,
soda, resinous oily or adhesive substances, while many other materials belonging to
the mineral, vegetable and animal kingdoms may be employed.
As regards the proportions of the amalgamating substances to be employed in
making the paste it goes without saying that they must necessarily vary according to
the nature and description of the goods it is desired to obtain.
To give a practical example of the performance of this invention, I shall now
proceed to describe the process I adopt in producing a variety of articles, whereby I
have obtained satisfactory results. Thus in order to make bricks I have found it
expedient to thoroughly and closely mix three parts of powdered terra-cotta with one
part of cement and one part of sand and then to mould the paste by compressing it
more or less the bricks thus obtained are then left alone for a time, lying on drying
trays the time varying between 20 and 40 days, after which the bricks are ready for
In the case of plastic earths one-fifth (by volume) of cellulose should be added
to the substances above named. For water works oil or resin is added to the paste
in the proportion of from 5 to 15 per cent.
use.
In the above description I have only enumerated some specific kinds of clay (or
loam) and amalgamating substances, so as to give an example of the manner in which
this invention may be put in practice, but it will be understood that any materials
suited to the purpose may be employed, and that the proportions hereinabove given
may vary according to circumstances and to the quantities of goods it may be desired
to obtain, without departing from the principle of the invention.
Having now particularly described and ascertained the nature of my said
invention 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 :-
In the manufacture of terra-cotta pastes for pottery and other articles and building
material generally, a method of operation consisting in subjecting the clay or other
like materials mentioned above as being adapted for such use to baking (or burning);
in then crushing them, unless this operation was performed previously; then kneading
them, together with amalgamating substances; and lastly moulding the paste by
compressing it more or less either by hand or by machinery as the case may be; all
substantially as described and specified.
1
ד.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, W.C., Agents for the Applicant.