IMPROVEMENTS IN THE MANUFACTURE OF METAL FOIL OR TINSEL
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Frank Wirth at the Office of the
Commissioners of Patents on the 5th February 1883. A communication
from Friedrich Haenle, councillor of commerce a person resident at Munich
in the empire of Germany
"
FRANK WIRTH of the firm of Wirth and Company Patent Solicitors, at
Frankfort on the Main, in the Empire of Germany IMPROVEMENTS IN THE
MANUFACTURE OF METAL FOIL OR TINSEL [A communication from Friedrich
Haenle, councillor of commerce a person resident at Munich in the empire of
Germany]
This invention relates to the manufacture of metal leaf for the use of metal or
gold beaters, and its object is to provide a cheaper, simpler, and more perfect mode
of preparing the leaf.
In the process hitherto employed for this purpose the metal or alloy after being
melted and rolled out, is piled in superincumbent layers which are thereupon
reduced to a certain degree of thinness by the blows of a hammer. The sleets are
afterwards dipped in a solution or pickle to cleanse them, and are finally packed
together again, placed under a baminer and beaten out once more.
The leaves thus
prepared are cut into squares, and each placed between vellum leaves and then
beaten out with a hammer to that state of thinness in which they are supplied to
the metal or gold beaters.
According to this invention the vellum leaves can be entirely dispensed with and
the use of the second light hammer also becomes unnecessary inasmuch as the first
heavy hammer can execute the whole operation.
My correspondent lias discovered that leaves, not completely hammered imme-
diately after coming out of the cleansing solution will not unite, under the influence
of blows from the hammer, with other leaves which have undergone an additional
amount of hammering, but will be kept separate and distinct by the last named set
of leaves, just as vellum leaves would keep them apart.
In carrying the said invention into practice, the entire leaves, in the state in
which it has hitherto been customary to get them immediately after the first
hammering, are placed in a furnace and heated, they are then cut through to the
best advantage in the middle of their length and the parts thus obtained are laid
between entire leaves not fully hammered and taken directly out of the cleansing
solution or pickle.

page_text: Shoders are then made up in such a manner that one half of a fully hammered
leaf shall invariably alternate with an entire leaf, only partially hammered and
coming directly from the solution. These shoders are then again placed under the
hammer and beaten by it, until the leaves have expanded and become so thin that,
being cut into the usual sizes of metal leaf, they are fit for delivery to the metal or
gold beater.
The half-hammered and pickled leaves which were interposed between the fully-
hammered leaves, are thus fully hammered themselves; these latter are now heated,
divided, placed between half-hammered leaves, and prepared, under the hammer,
ready for sale to the metal beater
The substitution of the metal leaf, as just described, in place of the vellum
leaves, presents the further advantage that the metal leaf is not rigid and tough
like the skin which does not stretch under the blows from the hammer, but on the
contrary it will expand as the hammering progresses quite in unison with the
inserted leaves, thus promoting the expansion of the latter and securing more
uniformity of expansion
As already stated there is no clinging together of the interposed leaves and the
leaves inserted in between them; the two sets of leaves readily separating after
being fully-hammered