Improvements relating to the Manufacture of Flexible Films for Photographic and other Purposes, and to Apparatus for use in such Manufacture.
Year: 1890

page_text: Date of Application, 30th July, 1890
Complete Specification Left, 30th Apr., 1891-Accepted, 30th May, 1891
PROVISIONAL SPECIFICATION.
Improvements relating to the Manufacture of Flexible Films for
Photographic and other Purposes, and to Apparatus for use in
such Manufacture.
I, BENJAMIN JOSEPH EDWARDS, of The Grove, Hackney, in the County of
Middlesex, Photographic Chemist, do hereby declare the nature of this invention
to be as follows:-
My invention relates to flexible films for photographic and other purposes, and
to apparatus for use in the manufacture of such films; and my said invention is
chiefly designed to provide for the more rapid and perfect drying of the moist films
and for the recovery, during the drying process, of the solvent or solvents used in
the previous stage or stages of the manufacture of the said films.
My said invention relates chiefly to flexible films designed to be covered or
coated with a suitable emulsion so as to form a sensitized service for photographic
purposes. And my improvements are very advantageous in the case of films which
are produced by dissolving suitable materials such as pyroxyline, soluble cotton,
camphor and castor oil in the solvents usually employed for the purpose such as
acetate of amyl, ether, alcohol, wood naptha or a mixture of these solvents.
In the manufacture of such films, the material is usually spread upon a plate of
glass or other suitable flat surface, in a fluid or semi-fluid condition, and it has
heretofore been customary to allow the vapourized solvent or solvents to escape
into the atmosphere. As these solvents, and especially the amyl acetate are
expensive, considerable loss is involved in the escape of the same. Moreover, when
amyl acetate is used, by reason of the powerful odour of this solvent, its escape into
the atmosphere is very objectionable to residents and passengers in the vicinity of
the factory where the films are produced.
By my present invention, however, I am enabled to obviate this objection and to
recover the solvent or solvents in such a manner that the same can be repeatedly
used in the manufacture of the films, and I can carry on the manufacture of the
films without vitiating the atmosphere or impregnating the same with the vaporized
solvents.
In carrying my said invention into practice I use plates of glass or other suitable
material of any required dimensions and of sufficient length for the films, and I
cause these plates to travel horizontally upon a level table or upon a travelling
band, or rollers so adjusted that the upper surface of the plate shall be as nearly as
possible level, and I make the plates to travel under a distributor, preferably of
one of the forms described by me in my Specifications No. 8643 of 1884 or
No. 8917 of 1885, the said distributor being connected with a reservoir containing
the fluid material which is to form the films, and with which the plates are by these
means coated.
+
Instead of allowing the moist films to dry in the manner heretofore practised, I
pass the plates carrying the semi fluid films directly into a suitable closed drying-
chamber, which is heated by a current of warm air or by other convenient means.
The volatile solvent or solvents are conducted into a suitable receiver provided
with a refrigerator or condenser, whereby they are condensed.
The condensed
solvents are collected in a suitable vessel and are again used in the manufacture of

page_text: flexible films, thus effecting great economy in the production of such films. When
heated air is used it is either forced into, or drawn through the drying chamber or
box by means of suitable apparatus such as a blower or an exhaust-fan. Or the
vaporized solvents are drawn from the drying chamber by means of one or more
suitable pumps, whereby they are compressed; they are then cooled while in a
state of compression, and are subsequently condensed by the reduction of
temperature which takes place when they are allowed to expand. Or I condense
the vaporized solvents in any other convenient manner.
Dated this 30th day of July 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Flexible Films for
Photographic and other Purposes, and to Apparatus for use in
such Manufacture.
I, BENJAMIN JOSEPH EDWARDS, of The Grove, Hackney, in the County of
Middlesex, Photographic Chemist, 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 :-
My invention relates to flexible films for photographic and other purposes, and
to apparatus for use in the manufacture of such films; and my said invention is
chiefly designed to provide for the more rapid and perfect drying of the moist films,
and for the recovery, during the drying process, of the solvent or solvents used in
the previous stage or stages of the manufacture of the said films.
My said invention relates chiefly to flexible films designed to be covered or
coated with a suitable emulsion so as to form a sensitized surface for photographic
purposes. And my improvements are very advantageous in the case of films which
are produced by dissolving suitable materials such as pyroxyline, soluble cotton,
camphor and castor oil in the solvents usually employed for the purpose, such as
acetate of amyl, ether, alcohol, wood naptha, or a mixture of the solvents.
In the manufacture of such films, the material is usually spread upon a plate or
strip of glass or other suitable flat surface, in a fluid or semi-fluid condition, and it
has frequently been customary to allow the vaporized solvent or solvents to escape
into the atmosphere. As these solvents and especially the amyl acetate are
expensive, considerable loss is involved in the escape of the same. Moreover,
when amyl acetate is used, by reason of the powerful odour of this solvent, its
escape into the atmosphere is very objectionable to persons employed in the
manufacture as well as to residents and passengers in the vicinity of the factory
where the films are produced.
"By my present invention, however, I am enabled to obviate this objection and to
recover the solvent or solvents in such a manner that the same can be repeatedly
used in the manufacture of the films, and I can carry on the manufacture of the
said films without vitiating the atmosphere or impregnating the same with the
vaporized solvents.
In carrying my said invention into practice I use plates strips or beds of glass or
other suitable material of any required dimensions, and of sufficient length for the
films, and I cause these plates to travel horizontally upon a level table or carrier
or upon a travelling band or 'rollers so adjusted that the upper surface of the
plate shall be as nearly as possible level, and I make the plates to travel under
a distributor or coating device preferably of one of the forms described by me in
my Specifications No. 8643 of 1884, or No. 8917 of 1885, the said distributor being
connected with a reservoir containing the fluid material or solution which is to form
the films, and with which the plates are by these means coated. Instead of

page_text: allowing the moist films to dry in the manner heretofore practised, I pass the
plates carrying the semi-fluid films, directly into a suitable closed evaporating or
drying chamber which is heated by steam or hot air coils or pipes, or by a current
of hot air generated in a furnace or combustion chamber, or by other convenient
means, and the temperature of the said evaporating or drying-chamber is maintained
at a proper degree or increased gradually as the operation advances. The volatile
solvents are conducted into a suitable receiver provided with a refrigerator or
condenser, whereby they are condensed into liquid form so that they can be again
used in the manufacture of flexible films, thus effecting great economy in the
production of such films. When heated air is used, it is either forced into, or
drawn through, the closed evaporating or drying chamber by means of suitable
apparatus, such as a blower or an exhaust-fan. Or the vaporized solvents are
drawn from the drying-chamber by means of one or more suitable pumps whereby
they are compressed; they are then cooled while in a state of compression, and
are subsequently condensed by the reduction of temperature which takes place
when they are allowed to expand. Or I condense the vaporized solvents in any
other convenient manner.
The dried films made as above described are then coated with a suitable emulsion
and dried in an open chamber or chambers provided with moveable racks or in an
evaporating or drying chamber substantially similar to that above described.
In the accompanying drawings I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure is a vertical longitudinal central section and
Figure 2 a transverse section on the line a z Figure
drawn to an enlarged
scale showing my improved apparatus for manufacturing flexible films.
Like letters indicate corresponding parts throughout the drawings.
A is a closed evaporating or drying-chamber, B B are the condensers, C, C, are
the glass or other plates or strips for receiving the solution or liquid material to
form the films.
a is a table or carrier mounted upon flanged wheels or rollers a¹ adapted to run
upon rails secured to the floor or other surface, so as to be capable of being readily
moved into position opposite the chamber A for the purposes hereinafter mentioned.
The table or carrier à moreover is provided with rollers c upon which the glass or
other plates or strips C are supported. is a trough or receptacle containing the
solution or liquid material for forming the films. To feed or move the plates or
strips C under the trough or coating device I provide the following mechanism,
that is to say, e is a small electric or other motor secured to the frame of the table
and connected by means of a strap or belt el or in any other suitable manner with
a pulley secured upon the spindle or gudgeon of one of the rollers c. The
electric current for driving the electric motor e is supplied through flexible
conductors so as to admit of the free to-and-fro movements of the said table a upon
the rails b..
I sometimes connect some or all of the other rollers e to the driven' roller by
means of a suitable band or belt, or in any other convenient manner so that rotary
motion is imparted thereto from the said driven roller. Instead of an electric or
other motor one or more of the said rollers may be arranged to be driven by hand
by means of a crank-handle or in any other convenient manner.
The drying or evaporating chamber A is preferably arranged partially below
the floor level, as shown in Figures 1 and 2, and is provided with apertures A¹
having suitable doors A through which the plates D when coated or covered
with the solution or liquid material for forming the films can be introduced into
the interior thereof. The said chamber A is provided-moreover with a steam,
hot air or other heating coil or pipes A³, one or more ventilators A', and with
thermometers A for perinitting the temperature of the said chamber to be readily
ascertained. I sometimes however employ a perforated pipe or pipes connected
with a chamber or furnace for heating the air and with a pipe communicating
with the atmosphere, both of which pipes are provided with suitable cocks or

page_text: valves for regulating the admission of the hot and cold air to the chamber A
(as shown in dotted lines in Figure 1), thereby permitting the temperature of
the latter to be regulated. are beds, tables, or frames, arranged in the lower
portion of the said evaporating or drying-chamber A, and which are provided
with rollers. The rollers are in the same horizontal plane as the rollers con
the table a and are adapted to receive the plates C when the latter are fed into the
chamber A through the aperture A'. One of the said rollers moreover on
each of the tables or frames is arranged to be rotated by means of a crank
handle or otherwise for convenience of manipulating the plates C. I some-
times connect one or more of the other rollers to the driven roller by means
of suitable gearing, and I provide the said feed roller or rollers with rings of india-
rubber or other suitable material to enable them to take a better grip of the said
plates or strips. ggare cages, racks or plate-holders one of which is arranged in
combination with each of the beds or tables and is independently suspended in the
chamber A by means of a cord or chain g' one extremity of which is secured to a
grooved wheel or pulley h mounted upon a shaft or arbor i supported in suitable
bearings in the said evaporating or drying chamber A, and the other extremity
whereof is secured to the said rack or plate-holder. The racks or plate-holders g
are built up of bars or cross-pieces and are of such dimensions as to be capable of
passing freely on either side of the beds, tables or frames, and when raised as
hereinafter described, the side bars thereof will successively engage with and pick
up the plates C from the said frames or tables (as shown in Figure 2) the said
plates being of a sufficient width to project slightly at either side of the latter for
that purpose. f³ ³ are grooved antifriction rollers mounted upon the racks or
plate-holders g and adapted to bear against guide rods or bars ƒ (or the said anti-
friction rollers may be arranged to bear against the inner walls of the drying-
chamber A) during the vertical movements of the said racks or plate-holders. To
permit the raising of the racks or plate-holders to be effected I connect each of
the shafts or arbors through a worm-wheel j, worm k, shaft or spindle, chain
wheel, and chain m with a chain wheel n having a handle n¹. I provide moreover
upon each of the shafts or arbors i, a grooved wheel o to which is secured one end
of a cord or chain to the other extremity of which is attached a counterbalance
weight for facilitating the adjustment of the racks or plate-holders.
The upper extremity of the drying chamber A is connected through a pipe g
with an exhaust fan of any suitable construction, which latter is connected through
a pipe with the first condenser B. The condensers B, B' may be of any ordinary
and suitable construction, I prefer however to employ condensers such as shown
more clearly in Figure 1, t, tare vertical tubes secured at or near their extremities
in tube plates t' in the condenser B. The tubes communicate with spaces B2 B2*
in the said condenser and a circulation of water or other cooling medium is main-
tained in the space B³ round the said tubes and between the tube plates el by means
of pipes u, u' the latter of which is provided with a stop-cock or valve u². ³ is a
drain pipe provided with a stop-cock or valve u for removing the condensed
solvents from the bottom of the said condenser B, which is preferably formed
conical as shown. The condenser B is also provided with tube plates t, and
vertical tubes communicating with spaces B₁ B** in the said condenser, and
having an air tight space B5 round the said tubes t³ and between the said tube
plates. The upper space B' is open to the atmosphere, and is formed of larger
dimensions than the lower space B₁, and is intended to be filled with a suitable
freezing mixture, or with ice. is a pipe communicating between the lower
space 132* in the condenser B and the upper part of the space B round the tubes t³.
is a pipe or funnel communicating with the said space 1 and with the atmo
sphere. w is a cock or valve for removing the condensed solvents from the space B,
and wis a drain pipe provided with a stop cock or valve w³ for removing the
drainage from the refrigerating mixture or ice in the upper space B, which passes
down the tubes to the lower space B**. The air and vapours removed or
exhausted from one or more of the evaporating or drying chambers A. by the

page_text: exhaust fan, are delivered through the pipe to the upper space B² in the con-
denser B, and pass down the tubes t to the lower space 132. The said air and the
remaining or uncondensed vapours then pass through the pipe to the space B³
round the tubes in the second condenser B', and the said vapour is condensed
therein, the air passing up or escaping through the pipe or funnel c'. It is obvious
that I can employ either or both of the condensers B 13. Instead of the above
described vertical tubes I sometimes employ tubes arranged horizontally, or a
suitable coil, or coils.
g
In using my improved apparatus the plates C are passed or fed consecutively by
the feed roller or rollers c, and electric or other motor e, along the table or
carrier a, and under the distributor or coating device (by which a coating or
covering of solution or liquid material to form a film is deposited thereon) on to
the rollers on one of the beds or tables in the evaporating or drying chamber A
the complete insertion of the said plates into the latter being effected by the feed
roller or rollers, and crank handle f. The cage rack or plate-holder is raised
by means of the hereinbefore mentioned gearing so as to successively engage
with and pick up the said plates. Both the racks or plate-holders are charged
or filled with coated plates or strips in this manner. To prevent the said racks or
plate-holders from being raised too high or so that the next or succeeding cross
bars thereof pass the upper surface of the rollers before one of the plates C is
deposited thereon, I provide in combination with each of the said racks or plate-
holders a inovable stop or I arrange a bell or alarm which will be rung or sounded
when the said rack or plate-holder g is sufficiently raised to admit of the insertion
of a fresh plate into the chamber A. During the filling or charging of the said
drying-chamber A the exhaust fan r sucks or draws atmospheric air through the
aperture A and prevents the escape of any noxious fumes or vapours, the said
fumes or vapours being drawn or sucked in along with the said air and passed to
the condenser or condensers. When both the cages, racks or plate-holders in the
evaporating or drying-chamber A. are full the door A is closed and the heat
required to dry the films is supplied by means of the coil or pipes A³ or otherwise
(the temperature of the said chamber being maintained at a proper degree, or
gradually raised as the said drying advances as hereinbefore mentioned) the
action of the exhaust fan being continued and the fumes or vapours given off
removed thereby and passed to the condensers B B¹.
g
When it is desired to manufacture sensitized films, the plates or strips carrying
the dried films are then removed one by one from the chamber A. in a similar
manner and the said films are coated with a sensitive emulsion by passing them
under another distributor or coating device. The said plates or strips carrying
the sensitized films are dried in movable racks or plate-holders similar to those
hereinbefore described, which racks or plate-holders need not in this instance be
mounted in a closed chamber, but may be open to the atmosphere.
The sensitized films are removed from the plates or strips by winding them on a
suitable roller, or by means of any other convenient stripping device.
It is obvious that I can employ a battery or set comprising any convenient
number of the evaporating or drying chambers A. In the latter case cross rails
and tables substantially similar to the table a but without the distributor or coating
device, are provided for transporting or moving the plates carrying the films.
-
It will be seen that by means of my improved apparatus the plates or strips C
carrying the films are maintained level through the whole process of manufacturing
and sensitizing, and that I am enabled moreover to carry on the various stages of
the said process in a continuous manner. I am enabled moreover to recover the
whole or the greater portion of the solvents used in making the solution or fluid
material for coating the plates C to form the said films.
. It is obvious moreover that I can somewhat modify the construction of my
improved apparatus without departing in any way from the nature of my said
invention. For instance the cages, racks or plate-holders y may be arranged in
receive the plates C directly from the table a upon suitable rollers arranged to

page_text: parallel rows, the gudgeon or spindle of one or more of the said rollers in each row
being provided with pinions, which pinions are adapted to engage successively (when
the said cages or racks are raised or lowered) with a toothed wheel, upon the shaft
or spindle of which is arranged a suitable crank handle and by means of which the
said roller or rollers can be successively rotated in one or the other direction for
feeding or moving the plates C into or out of the chamber A. Instead of two
racks or plate-holders I sometimes employ any other convenient number in the
drying chamber A.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that I am aware
that it has been previously proposed to recover the solvents employed in the
maunfacture of photographic flexible films and that closed drying receptacles or
chambers have been used in such process and I make no general claim to such
process or apparatus but what I claim is :-
First. In an apparatus for the manufacture of flexible films, a drying rack so
constructed as to contain a number of horizontally superposed plates in a perfectly
level position and out of contact with each other, the said rack being arranged to
move vertically, for the purpose herein described.
Second. In an apparatus for the manufacture of flexible films, a closed receptacle
or chamber provided with a plate-drying rack, so arranged as to be capable of
vertical movement therein, substantially as above described and illustrated in the
drawings, for the purpose above set forth.
Third. In an apparatus for the manufacture of flexible filins, the combination of
the coating apparatus, the closed drying chamber, the vertically moveable rack, the
exhausting device, and the condenser, for the purpose herein described.
Fourth. In an apparatus for the manufacture of flexible films, the table or tables
having practically frictionless beds for feeding and receiving the plates successively
into the vertically moveable drying rack, in combination with the said rack, for the
purpose herein set forth.
Fifth. The improved apparatus for the manufacture of flexible films, con-
structed substantially as above described with reference to the accompanying
drawings.
Dated this 25th dow of Anvil 1801
BENJAMIN JOSEPH EDWARDS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.