MENTS IN THE MANUFACTURE OF TIN AND TERNE PLATES
Year: 1881

page_text: PROVISIONAL SPECIFICATION left by James Spence at the Office of the
Commissioners of Patents on the 4th June 1881.
JAMES SPENCE, of Walbrook, in the City of London, Iron Merchant.
MENTS IN THE MANUFACTURE OF TIN AND TERNE PLATES."
"IMPROVE-
By the ordinary method of manufacturing tin plates there is a serious waste of
tin and oil, and the cost of labor is heavy. In addition, the method of cleaning
the plates now in use is cumbersome and expensive.
To effect an economy in these respects I propose to adopt the following method
of manufacture :-I deposit the tin on the sheets of iron by the process well known
in other trades as electro plating, but in order to expedite the work I use machines
of greater power than have usually been employed, and by preference the dynamo-
electric machines patented by William Elmore, the Patcuts being dated Sept. 4th,
1879, No. 3565, and Sept. 22nd, 1880, No. 3832.
By this process the tin is deposited on the iron without any waste by oxidation.
When it is desired to make tin plates as cheaply as possible, I first place the plates
in a solution of zinc and deposit a film of that metal on the surface, and I then
place them in a solution of tin and deposit a coating of that metal on the zinc
surface. In manufacturing terne plates I coat the sheet of iron as before with zinc
and then deposit a coating of lead by electric process. I thus when making
tin plates reduce the quantity of tin hitherto required, and in the manufacture of
terne plates I avoid the use of the costly metal tin altogether.
The electro tinned plates when taken from the bath have not the smoothness
and polish which the market requires. To produce this I proceed as follows:-
-
I have a stove placed conveniently for the purpose and heated slightly above
the temperature at which tin melts. As the plates are taken out of the electro
bath I place them in a rack containing about 24 pins. These racks as they aro
fitted I place in the stove for the period of time required to render the tin on the
surface fluid. I then pass the plates through a pair of polished steel rolls, taking
care to pass them through the rolls with that edge first which was the bottom
edge in the rack.
Or in order to avoid the use of heat I arrange one or more pairs of polished
steel rolls in succession, and adjusted so as to bear on the plate with some pressure.
On taking the plates from the electro bath I pass them through these rolls which
removes the inequalities of the tinned surfaces. In order to give the polish which

page_text: is desirable, I pass the plates on to a table having upon it a pair of rolls rotating
at great speed and coated with cloth or other material suitable for the purpose.
These rolls are arranged so as to rotate in the reverso direction to the traverso of
the plate, and hence the plate has to be pushed through them. It may be passed
through more than once, or through a succession of pairs of rollers. To the surface
of these rolls may be applied one of the well known materials used in polishing.
These polishing rollers may be used with advantage in finishing plates tinned in
the ordinary manner. At present the oil on the surface of the plate is removed by
rubbing in bran and wiping, for which purpose women are employed. By passing the
oily plate through the rolls described, it will be better cleaned and at a saving in
cost as compared with the present inefficient and troublesome method of cleaning.