IMPROVEMENTS IN STRAINER PLATES, USED IN THE MANUFACTURE OF PAPER
Year: 1886

page_text: I HENRY WATSON, Manufac Engineer, of High Bridge Works Newcastle on
Tyne in the County of Newcastle on Tyne do hereby declare the nature of
my invention for IMPROVEMENTS IN STRAINER PLATES, USED IN THE MANUFACTURE
OF PAPER, and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:-
My invention consists in improvements in covering the upper surface of the
plates by the electro-type or plating process with a layer of metal or other material,
so making the plates smoother as well as causing them to wear longer, and when
again worn, the same process can be repeated and a much extended service obtained
from them.
Strainer plates for straining paper-pulp in the manufacture of paper as now
generally used, were introduced by me many years ago.
They consist of plates of a specially hard gun-metal or bronze having a great
number of fine slits cut in the solid bronze, through which the pulp only is made
to pass, to separate it from knots or other impurities.
After such plates have been in use for some time, the fine slits become worn and
enlarged in places, and the pulp becomes more or less fouled by the passing of
knots or impurities, when it becomes necessary to throw the plates out and re-place
with new.
Heretofore I have repaired these worn plates by bringing the worn edges of the
slits together by hydraulic pressure, hammering and other means, and the openings
are again made even by re-slitting by machinery specially designed and employed
in the manufacture of the plates.
According to my invention, when the slits in the plates become much worn,
I prefer to restore them by covering the upper surface and the wearing part of the
plates to wit the slits-by the electro-deposition of a hard bronze, copper, nickel,
or other suitable metal,-by which means I obtain a renewed plate that will wear
longer & work better than those hitherto pressed, hammered or 'soldered-up.'
In my Patent of Sep 29th 1871, referred to, so much difficulty was found in
bridgeing-over & depositing the metal in the worn slits that I could not always
avail myself of the process.

page_text: Since 1871, by improvements in the electro-type process,-by increased power
& the temporary application of a soft conducting metal as lead, tin, zinc or such
alloys, or plumbago with or without gypsum run into the openings or grooves, so
that it by conduction facilitates the deposit of the metals upon the edges of the
slits as well as upon the upper surface of the plates. The soft metal or conducting
material is afterwards removed and the slits in the plates re-formed either by
placing in a machine designed for the purpose or by re-slitting with a fine
hand-saw.
The parts not requiring to be renewed can be covered over with a suitable
protective material or varnish before immersing the plate in the bath. The slits
in the plates may be made even or equalised either before the electro-deposition as
described or afterwards.
Having now particularly described the nature of my improvement and in what
manner the same is to be performed, I hereby declare that what I claim is,-
I. Firstly by being able to deposit metals or their alloys in greater thickness
than before, and in more equal substance, by the use of more powerful dynamo-
electric machines, and
II. Secondly by the use of the temporary conducting metal or material
introduced into the grooves, thereby accomplishing the covering of the whole of
the upper surface as well as the worn, or otherwise slitted openings with copper,
bronze, nickel or other suitable metal.
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