Improvements in the Production of Tin Plates, and in Apparatus for that Purpose.
Year: 1890

page_text: Date of Application, 3rd Jan., 1890
Complete Specification Left, 14th Mar., 1890-Accepted, 19th Apr., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Production of Tin Plates, and in Apparatus
for that Purpose.
We, IVAR BANG and ALFRED RUFFIN both of 18 Avenue d'Antin Paris, France,
Chemists, do hereby declare the nature of this invention to be as follows:-
It is well known that in industries in which tin plate is used it is required that
the surface of such plates should be as brilliant as possible. In order to obtain
this result in the highest possible degree, it is necessary to take great precautions
in the tinning process, which constitutes a very expensive, delicate and difficult
operation.
Our invention relates to new means employed in the tinning of plates whereby
the required brightness is insured in a very easy manner; before describing the same
we will shortly state the process generally employed for this purpose.
The iron plates are first immersed in a bath of fused chloride of zink in order
to prepare them for the reception of the tin; they are then successively immersed
in two baths of molten tin. These baths are kept covered by a thick layer of palm
oil or of tallow &c.
This oil, which is continuously being heated on the tin, gives off deleterious
vapours, which irritate the lungs and eyes of the workmen.
It also often takes fire and is thus a source of constant danger; notwithstanding
this, its use could not up to the present time be dispensed with, for two reasons.
Firstly this layer of oil or grease prevents the surface of the bath of molten tin
from becoming oxydized by contact with the air which would cause dull places on
the coated plates; secondly when the tinned sheet is withdrawn from the bath it
is necessary that it should be covered by a thin adhering layer of grease which
will allow the plate to cool out of contact with the oxygen of the atmosphere,
without. which the surface of the tin, being still hot, would oxydise to a certain
extent and assume blue and yellow tints.
The use of the oil or grease has however other inconveniences.
The plates
coated with tin and covered with grease stil! hot, require to be at once freed from
the grease. This is effected by scouring the plates repeatedly with absorbant matter,
such as sawdust, bran &c. a very expensive operation, requiring a considerable
amount of hand labor, without taking into account the fact that the brilliancy of
the plates is considerably reduced thereby, while a complete removal of the grease
is scarcely attained, so that in some cases it is requisite to effect a final cleansing
with turpentine.
Our invention has for its object to dispense entirely with the use of oil or grease
in the tinning of plates, thus obviating all the serious disadvantages above referred
to, and we effect this by an exceedingly simple and practical method. The invention
consists namely in effecting the tinning of the plates in an atmosphere which is
deprived of free oxygen. For this purpose we employ either a carbonaceous gas,
or air which has been deprived of free oxygen by being passed in contact with
incandescent fuel; but any other gas free of oxygen can be used, provided it does
not contain sulphur or chlorine.
For effecting the tinning operation according to our invention, we employ a
hermetically closed chamber, the top of which is made of glass so as to observe
the interior, which chamber contains firstly a tank with two compartments, one
filled with hydrochloric acid, and the other with molten tin, the tank being suitably
heated from below, secondly the chamber contains another tank filled with molten
tin and thirdly it contains a horizontal endless chain web, leading through a closed
passage extending from one end of the chamber and surrounded by a cold water

page_text: jacket. At the opposite end of the chamber is a door for gaining access to the
same and a narrow opening closed by a flap or slide through which the iron plates
are introduced. The front of the chamber has three pairs of holes, two pairs of
which are situated opposite the two tanks, while the third pair is situated between
them. To these holes are attached in an airtight manner leather or other gautlets
through which three workmen standing outside the chamber can extend their arms
into the interior for manipulating the plates.
A pipe establishes a communication between the interior of the chamber and a
source of carbonic acid or other suitable gas.
The operation with this apparatus is as follows. The tanks being charged with
molten tin and hydrochloric acid, and the chamber filled with carbonic acid gas, the
plates are passed in through the narrow opening, and are seized by the first workman
who by means of the gauntlets immerses the plate first in the hydrochloric acid and
then in the first tin bath; he then hands the plate to the second workman who
brushes off the superfluous tin from the plate and then hands it to the third workman,
who first dips it into the second tin bath, and then places it upon the endless web.
In being carried through the cooled channel the plate becomes sufficiently cooled to
allow of its being removed to the open air at the other end.
The workinen observe the operations through the glass top of the chamber.
Instead of the workmen being situated outside the chamber they might be situated
inside the same, being in that case provided with helmets like those of divers, supplied
with fresh air.
T
1000
COMPLETE SPECIFICATION.
Improvements in the Production of Tin Plates, and in Apparatus
for that Purpose.
We, IVAR BANG, and ALFRED RUFFIN, both of Paris, France, Chemists, 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 :-
It is well known that in industries in which tin plate is used it is required that the
surface of such plates should be as brilliant as possible. In order to obtain this result
in the highest possible degree, it is necessary to take great precautions in the tinning
process, which constitutes a very expensive, delicate and difficult operation.
Our invention relates to new means employed in the tinning of plates and the like
whereby the required brightness is insured in a very easy manner; before describing
the same we will shortly state the process generally employed for this purpose.
The iron plates are first immersed in a bath of fused chloride of zinc in order to
prepare them for the reception of the tin; they are then successively immersed in two
baths of molten tin. These baths are kept covered by a thick layer of palm oil or of
tallow &c.
This oil which is continuously being heated on the tin, gives off deleterious vapours,
which irritate the lungs and eyes of the workmen.
It also often takes fire and is thus a source of constant danger; notwithstanding
this, its use could not up to the present time be dispensed with for two reasons.
Firstly this layer of oil or grease prevents the surface of the bath of molten tin
from becoming oxidised by contact with the air which would cause dull places on the
coated plates; secondly, when the tinned sheet is withdrawn from the bath it is
necessary that it should be covered by a thin adhering layer of grease which will
allow the plate to cool out of contact with the oxygen of the atmosphere without
which the surface of the tin, being still hot, would oxidise to a certain extent and
assume blue and yellow tints.
The use of the oil or grease has however other inconveniences. The plates coated
with tin and covered with grease still hot, require to be at once freed from the grease,

page_text: This is effected by scouring the plates repeatedly with absorbent matter such as saw-
dust, bran &c. a very expensive operation, requiring a considerable amount of hand
labour without taking into account the fact that the brilliancy of the plates is con-
siderably reduced thereby, while a complete removal of the grease is scarcely attained,
so that in some cases it is requisite to effect a final cleansing with turpentine.
Our invention has for its object to dispense entirely with the use of oil or grease
in the tinning of plates thus obviating all the serious disadvantages above referred to,
and we effect this by an exceedingly simple and practical method.
The invention consists namely in effecting the tinning of the plates in an atmo-
sphere which is deprived of free oxygen. For this purpose we employ either a
carbonaceous gas or air which has been deprived of free oxygen by being passed in
contact with incandescent fuel; but any other gas free of oxygen can be used, pro-
vided it does not contain sulphur or chlorine.
For effecting the tinning operation according to our invention, we employ a
hermetically closed chamber, the top of which is made of glass so as to observe the
interior, which chamber contains firstly a tank with two compartments one filled with
hydrochloric acid, and the other with molten tin, the tank being suitably heated from
below, secondly the chamber contains another tank filled with molten tin and thirdly
it contains a horizontal endless chain web leading through a closed passage extending
from one end of the chamber and surrounded by a cold water jacket. At the opposite
end of the chamber is a door for gaining access to the same and a narrow opening
closed by a flap or slide through which the iron plates are introduced. The front of
the chamber has three pairs of holes, two pairs of which are situated opposite the two
tanks, while the third pair is situated between them. To these holes are attached in
an air tight manner leather or other gauntlets through which three workmen standing
outside the chamber can extend their arms into the interior for manipulating the
plates.
A pipe establishes a communication between the interior of the chamber and a
source of carbonic acid or other suitable gas.
The accompanying drawing shews a construction of apparatus for carrying out
our above described invention; Fig. 1 shews an elevation Fig. 2 a sectional plan
Fig. 3 a cross section on line 1-2, and Fig. 4 an end view shewing the opening for
the introduction of the plates.
C, B, are the two vessels or pans built in the masonry A containing the requisite
furnaces for heating; the vessel B is divided by a partition, the one compartment
containing the bydrochloric acid, and the other the molten tin, while the other vessel C
contains also molten tin. D is the endless travelling web passing out through an
extension G cooled by the circulation of water.
E is the hermetically closed glazed cover, having openings F with leather or other
gauntlets attached thereto; a is the tube for the introduction of carbonic acid gas,
any excess of which escapes through the extension G. c is the opening, closed by a
flap, for the introduction of the plates, and 6 is the door for gaining access to the
interior of the casing.
The operation with this apparatus is as follows. The tanks BC being charged with
molten tin and hydrochloric acid and the chamber filled with carbonic acid gas, the
plates are passed in through the narrow opening C and are seized by the first workman
who by means of the gauntlets immerses the plate first in the hydrochloric acid and
then in the first tin bath; he then hands the plate to the second workman who brushes
off the superfluous tin from the plate and then hands it to the third workman, who
first dips it into the second tin bath and then places it upon the endless web D. In
being carried through the cooled channel the plate becomes sufficiently cooled to allow
of its being removed to the open air at the other end.
The workmen observe the operations through the glass top of the chamber.
Instead of the workmen being situated outside the chamber they might be situated
inside the same being in that case provided with helmets like those of divers, supplied
with fresh air,

page_text: Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. The process of tinning metal plates and other objects wherein the operations of
tinning is carried on in an atmosphere fred from uncombined oxygen and other
bodies, such as sulphur and chlorine, that will attack tin, substantially as herein
described.
2. The use for carrying out the process referred to in the preceding claim, of
apparatus consisting of an enclosed glazed chamber containing the baths of molten.
tin and acid necessary for the tinning operation, and having firstly orifices with
gauntlets or equivalent appliances for enabling the workmen situated outside the
chamber to manipulate the objects inside the same, secondly a closed aperture for.
introducing the objects to be tinned, and thirdly a refrigerated exit passage for the
tinned objects through which they are conveyed on a travelling apron, or equivalent
device, substantially as herein described.
Dated this 12th day 1800
ABEL & IMRAY,
Agents for the Applicants.