An Improved Process for and Method of Producing Slabs for Building or Decorative Purposes.
Year: 1898

page_text: Date of Application, 29th June, 1898-Accepted, 29th June, 1899
COMPLETE SPECIFICATION.
An Improved Process for and Method of Producing Slabs for Building
or Decorative Purposes.
I, WILHELM ANTONY, of Trier, Prussia, 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:-
From time immemorial people have been endeavouring to produce doors, furni-
ture, wall facings, partitions, and the like, of a strong material not liable to
warping, but such attempts have hitherto proved fruitless because high prices
and other circumstances had to be taken into consideration. For instance, for
panels, in some instances, hard mill-boards, papier-mache, iron plate, marble,
slate, black and coloured glass, and the like, were employed. All these materials
are more or less liable to faults which may be summed up as follows:-
Some of these materials are not durable even when coated with the best possible
paint, and not sufficiently strong, others are liable to become wavy, elastic and
moveable unless of great thickness, while, if used in a sufficient thickness, they
are too heavy and too expensive; others again, though used in considerable thick-
ness, are brittle and unable to resist the action of fire or water. In any case, how-
ever, the materials mentioned above are not suitable for covering large surfaces,
so that one has been obliged to adhere to wood notwithstanding its many draw-
backs, such as little resistance to rotting, shrinkage, cracking, warping, fire,
worms, fungus, and the like.
But thanks to the present invention, a product has been discovered which is
capable of replacing wood and other materials for the aforesaid purposes while
answering them better than these. Slabs of this kind may be produced as
follows:-
Asbestos boards are painted with diluted water-glass, in one or several coats,
and thereupon sprinkled over with glass or emery powder. When the slabs are
completely dry, metal plates of suitable size, and suited for the purpose, are
attached to them on both sides by means of a cement made of caseine, hydraulic
lime, chalk, emery powder, and burnt magnesia, and the whole is dried under
pressure. When the slabs are dry, in order to prevent any moisture from pene-
trating into the inside layer the edges are coated with a waterproof material and
the projecting edges of the metal plates are bent down. In the case of such com-
posite plates or slabs which are to be exposed to water or moisture, the asbestos
boards are previously placed into a bath of chloride of magnesia dissolved in
alcohol, and it is only after this that they are treated with water-glass, and glass
or emery dust. For composite plates or slabs which do not require to be highly
fire-resisting and strong, plates of soft metals such as zinc, nickel, aluminium,
brass, or the like, may be applied, for walls, ceilings, roofing, and the like,
while for larger sized slabs or composite plates, which are more exposed to risk
of fire and great pressure, iron or steel plate or the like would be requisite. Such
composite plates or slabs have the great advantage of being light, durable, fire-
proof, and proof against fungus or rotting. But a point deserving particular

page_text: attention is that any desired decoration of the slabs can be executed before they
are mounted in position.
Such a slab or composite plate, produced according to the process described
above possesses an exceedingly great relative strength, as the supporting solid
parts, (the metal plate facings) owing to their distance from the "neutral fibre,"
increase the moment of inertia of the section, and this all the more the further the
metal plates are from each other, that is to say the thicker the intermediate layer
is made.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:
-
1. The process for the production of plates or slabs of great relative strength
with little weight, characterised by the use of a light material (such as asbestos,
board or the like in slabs) which is faced on both sides with metal-plate, and
by means of powerful pressure, with the aid of a cement, is firmly joined to the
intermediate layer.
2. Slabs or plates of great relative strength with little weight, produced in
accordance with the process characterised in Claim 1.
Dated this 28th day of June 1898