Flexible Films for Photographic and other Purposes and Apparatus in Connection with the Manufacture thereof.
Year: 1887

page_text: Date of Application, 22nd Nov., 1887
Complete Specification Left, 22nd Aug., 1888
Complete Specification Accepted, 28th Sept., 1888
Flexible Films for Photographic and other Purposes and Apparatus
in Connection with the Manufacture thereof.
I, JOHN EDWARD THORNTON, of 3, New Lorne Street, Moss Side Manchester, in
the County of Lancaster, Manufacturer, do hereby declare the nature of my invention
for FLEXIBLE FILMS FOR PHOTOGRAPHIC AND OTHER PURPOSES, AND APPARATUS IN
CONNECTION WITH THE MANUFACTURE THEREOF, to be as follows:-
The object of this invention is to provide a substitute for glass for Photographic
and other purposes, technically known as a "film" which shall be more transparent
or translucent than those heretofore in common use, and more easy of manipulation.
Films such as are hereinafter more definitely described, may be used in obtaining
various kinds of photographic impression such as negatives, positives, opals, trans-
parencies, &c.
They also have similar advantages to other films, such as lightness, portability, &c.
whilst there is a total absence of the troublesome "grain" so commonly seen in films
having a paper basis.
They also print much quicker by reason of thier greater transparency.
In making other kinds of photographic films it is usual to prepare them upon a
paper basis, which either remains permanently a part thereof, or is afterwards stripped,
off at some convenient part of the process.
In preparing films after the manner of this invention, I use a transparent or
translucent material known as "algin" (or a product thereof) in the following
ways:
I procure a suitable material upon which to prepare the film, but of such a nature
that the film may be stripped threfrom by the application of a little force.
Anything having a smooth surface, such as glass, ebonite, &c., may be used.
It should be known that the substance known as algin or alginate of soda, potash,
or other alkali, can be dissolved in water (cold or hot), and possesses the peculiar
property of becoining insoluble in water after treatment with dilute mineral acids or
lime salts. It can be bleached when desired and is better for film purposes if so treated,
before being used.

page_text: To prepare a skin or film of this substance. it is only necessary to dissolve sufficient
in water to make a thick glutinous solution which is then flowed out on a level
surface and allowed to dry spontaneously or by heat. The resulting film or coating
may be afterwards rendered insoluble in the manner already described, or may be
treated for this purpose before drying and as soon as flowed out, if necessary, but in
this case considerable contraction and shrinkage of the algin film is frequently' the
result.
By combining alginate of soda or alginic acid with silicate of soda or potash, a
flexible transparent film is produced which, when dry, is insoluble in water.
There are various ways in which a photographic sensitive film may be produced
viz:-
-
(1) Having obtained and dried a thin algin film in the manner described, the same
may be coated on one or both sides with sensitive gelatine emulsion in any convenient
manner.
(2) The said algin film may be coated only on one side with emulsion, or emulsion
on front and plain gelatine on the back.
(3) The said algin film may be coated on both sides with gelatine and afterwards
with sensitive emulsion on one or both sides.
(4) The complete photographic film, composed of alternate layers of algin, gelatine,
and sensitive gelatine emulsion may be prepared and supported upon a temporary
paper basis, from which it is afterwards stripped or detatched at any convenient time
(preferably after the photographic impression has been obtained thereon) in which
case the built-up film may be temporarily cemented to the paper backing by a layer
of soluble gelatine, gum, or other soluble cement, which can be afterwards removed
by treatment, with warm water.
(5) By another method the sensitive material may be incorporated with algin and
a thicker coating or series of coatings applied without any gelatine layers.
In the first three methods the algin skin forms the support permanently for the
sensitive layer, and in the 4th method the paper backing forms the support until such
time as it is thought advisable to remove it. In this latter case the whole is termed
a "stripping film." In the 5th method the algin support or basis also forms the
sensitive film itself.
Although it is possible to coat the previously prepared algin skin with gelatine
or sensitive emulsion without some kind of a temporary backing, there are certain
objections thereto, one of which is the tendency of the algin to absorb a considerable
portion of water from the gelatine, and so cause cockling, together with unequal
expansion and drying. This, in a measure; may be overcome by stretching or
straining the film till dry, or preparing it on a rigid surface instead.
In case the film is prepared on a flexible support, recourse may be had to rolling
or calendering the film between successive coatings, in order to remove creases caused
by unequal expansion &c.
I do not bind myself to any particular order or method of applying the various
coatings to produce the finished film, but in order to minimise the before-mentioned
difficulties of unequal drying and shrinkage of the film, I prefer the following or
somewhat similar order:
Having obtained a suitable surface as a support, I coat it first with gelatine and
then dry; then coat with algin and dry; then immerse for a few minutes in dilute
mineral acid or lime salts to render insoluble, dry; and afterwards apply the sensitive
gelatine emulsion, then again dry. It is better to interpose another coating of plain
gelatine between the algin and the sensitive layer to prevent the acid from affecting
the sensitive film.
If desired more than one layer of algin may be applied to seeure the requisite
thickness.
For "stripping films" the soluble or cementive coating may be interposed between
the paper backing and the algin coating in lieu of the gelatine coating. In the
case of stripping films, where it is necessary to remove the soluble cementive coating
by warm or hot water, it is necessary to treat all the gelatine in the film proper

page_text: with chrome alum or its equivalent, to render the gelatine layers insoluble in the hot
water. Glycerine may be added to the film to increase its flexibility.
By using a sensitive photographic film strengthened by means of algin in the
manner described, there is no necessity for afterwards strengthening the finished
negatives or photographic impressions by the addition of gelatine skins, collodion;
&c.; the finished negative being sufficiently strong and flexible when completed ; and
much time saved.
Another advantage of this invention is that the algin expands with the gelatine in
the developing solution consequent upon the absorption of water into the film.
In producing a flexible film in bands or rolls suitable for use in the roller slide
or for other purposes, I adopt or 1150 one or more of the hereinafter described
methods and appliances
In the first case it is necessary to have a temporary support upon which to
prepare the film in a sufficiently, long length, the said support to be capable of
withstanding the action of weak acids, water, and increase of temperature; to be
flexible and yet, rigid enough to counteract the cockling and shrinkage of the film
whilst the same is drying; and to seperate easily from the film when required.
For this purpose employ any of the following or any other suitable materials:
paper, waterproofed, waxed parchmentized, or otherwise suitably prepared (that
known as Willisden Waterproof paper may be used); sheet rubber; prepared
leather; American or other leather cloth having a glossy surface; the patent vulcanized
fibre, &c. &c. Paper or cloth may be sized, varnished, coated with rubber solution,
algin rendered insoluble, or may be treated in any other convenient way to prepare a
suitable surface.
Whatever material is used may be wound upon a stock spool, from which it is
paid off to the coating machine or machines, which apply the successive layers to its
surface. Suitable flanged guide-rollers, in connection with friction-rollers (one or
both sets being driven) conduct the meterial to the coating-trough in which is the
algin in a glutinous, seme-liquid condition. Here the band is passed over, under,
against, or around a coating-roller immerced in the trough, or against a ductor-roller
revolving in contact with the immersion-roller, and against guide rods to regulate
the thickness of the coating, whereby the band becomes coated with an even layer.
Another method of coating which may be adopted, is to place the stock spool in
bearings over the immersion-roller or ductor-roller and free to revolve in frictional
contact therewith; as the band is drawn off it becomes coated with the solution.
Weights or springs may be added to keep the spools in close contact.
After the algin coating the band may be allowed to pass through a bath or trough
of dilute-mineral acid to render the algin insoluble by precipitation of the alginic
acid, or, if preferred, this operation may be left till after the film has been dried.
The band is then conducted by flanged guide-rollers and friction-rollers and travelling
bands or tapes to the drying-apparatus which may be formed of the shape of long
boxes or tunnells surrounded or filled with hot air, steam, or a solution of acetate
of soda through or between which the band passes; or it may be formed of a number
of drying cylinders around which the band is conducted; or it may consist simply
of an apparatus for suspending or looping the moist band in a drying-room to which
hot air is introduced by mechanical or other means, or the temperature otherwise
raised to a suitable heat.
In case the algin film has not been passed through an acid bath previously, it must
be dried without anything touching its surface; but in case it should have been
precipitated and rendered insoluble through treatment in the manner aforesaid, the
face of the algin film may come in contact with the drying cylinders, and therefore
dry in much less time. The algin film, after drying, is ready for the coating of
gelatine or sensitive gelatine emulsion, which is applied in a similar manner to the
algin as hereinbefore described.
The algin film may still remain attached to its support whilst coating, unless it is
desired to coat both sides thereof, in which case the film is stripped and then passed
through the coating apparatus and then dried.

page_text: In the case of the gelatine or gelatine emulsion coating it is necessary that nothing
should come in contact with the face thereof, so that the band must be dried by
passing over drying cylinders with its face outwards, or preferably by suspension in
a drying room.
The band, after leaving the coating-trough may be allowed to travel vertically,
preferably through a shaft or chamber cooled by ice or cold air supplied by fans,
blowers, or other means to facilitate quick drying of the moist film. In the case of
a coating applied only to one surface of the band at a time 1 prefer to let the band
travel horizontally and perfectly level till the coating has set.
The band, if in one length, may be suspended automatically or by hand in loops,
until dry, cver suitable flanged-rollers, with friction-rollers revolving in frictional
contact therewith having collars so placed thereon as to grip the band at its edges
between the two rollers. One pair are placed to each loop so as to form the top thereof,
with proper space between the loops. Each set of rollers being driven at one uniform
speed will operate to keep the looped and suspended band constantly in motion whilst
drying; and the constant change of suspending-points will tend to equalise the drying
and prevent cockling of the film.
If the band should be divided into several shorter lengths, each one may be
suspended singly in a drying-apparatus; the said drying-apparatus or frame operating
to suspend each length one behind the other, with suitable space between them, and
to push or move the suspenders one space forward for each seperate length, auto-
matically. The several lengths may each have a weighted bar attatched to bottom end
in order to keep the film stretched until dry and thus prevent cockling. Or each
band may be seperately stretched on a drying or stretching frame in any position-
vertical or otherwise, by attaching to suitable stretching mechanism.
The film may be prepared in sheets on rigid surfaces when desired (by coating and
drying in the same manner as dry plates) and afterwards stripped. Films so prepare:
may be utilized in place of the ground glass focussing screen in cameras.
In the case of ordinary transparent films prepared according to this invention, the
film remains attached to its temporary support until it is finished and perfectly dry,
after which it is stripped and is then ready to be packed for use or wound on spools,
and forms a strong, flexible material.
To strip the film from its support I seperate a portion at one end by hand and
then attach the support to one reel and the film to another reel, and then cause
both to wind in opposite directions until the film and support are entirely seperated
throughout thier entire length.
By coating and drying both sides of the temporary support. either together or
separately, and afterwards stripping, two films may be prepared in the same time
as one.
In the case of "stripping films" the paper backing upon which they are prepared,
remains attached until the negative has been obtained, after which the stripping may
be done in the usual manner.
Dated this 92nd of Novuhan 1007

page_text: COMPLETE SPECIFICATION.
Flexible Films for Photographic and other Purposes and Apparatus
in Connection with the Manufacture thereof.
1, JOHN EDWARD THORNTON of 3 New Lorne Street. Moss Side Manchester in the
county of Lancaster Manufacturer 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 :-
The object of this invention is to provide a substitute for glass for photographic
and other purposes, technically known as a "film" which shall be more transparent
or translucent than those heretofore in ordinary use and more easy of manipulation.
Films such as are hereinafter more definitely described may be used in obtaining
various kinds of photographic impressions, such as negatives, positives transparencies
and the like. They have also similar advantages to other films such as lightness and
portability whilst there is a total absence of the troublesome "grain" so commonly
seen in films having a paper basis. They also print much quicker by reason of their
greater transparency.
In making other kinds of photographic films it is usual to prepare them upon a
paper basis, which either remains permanently a part thereof, or is afterwards stripped
off at some convenient part of the process.
25 45
In preparing films in accordance with this invention, I use transparent or trans-
lucent materials obtained from seaweed and known as "algulose," "algin' alginate
of Soda" and the like or any other suitable product or products of seaweed in one
or any of the following ways;-For the sake of brevity hereinafter term the said
materials "algin." It should be understood that the substance termed algin or
alginate of soda, potash, or other alkali, can be dissolved in water either cold or hot,
and possesses the peculiar property of becoming insoluble in water after treatment.
with mineral acids, lime salts, certain metals such as iron, silver or copper and many
other like substances; said algin can be bleached when desired, and is better for film
purposes if thus treated before being used. Various substances may be combined
with the algin if desired to give it certain properties, such as glycerine for flexibility,
silicates for hardness, chrome alum for toughness. I procure a suitable material
upon which to prepare the film, but of such a nature that the film may be stripped
therefrom by the application of a little force. Anything having a smooth surface
such as glass, ebonite or other like material may be used.
To prepare a skin or sheet of herein before described substance termed algin, it is
only necessary to dissolve sufficient of said algin in water to make a thick glutinous
solution, which is then flowed out on a level surface and allowed to dry spontaneously
or by heat. The resulting film or coating may be afterwards rendered insoluble in
the manner as herein previously described or may be treated for this purpose before
drying and as soon as flowed out, if necessary, but in this case considerable contraction
and shrinkage of the algin film is frequently the result.

page_text: By preferance I use a strong solution of calcium chloride to render the algin
insoluble but other solutions may be used to obtain various results.
I produce a photographic sensitive film by either of the following means :-
1. Having obtained and dried a thin sheet of algin in the manner described the
same may be coated on one or both sides with sensitive gelatine emulsion in any
convenient manner.
2. The said algin sheet may be coated only on one side with emulsion, or emulsion
on front and plain gelatine on the back.
3. The said algin sheet may be coated on both sides with gelatine and afterwards
with sensitive emulsion on one or both sides.
4. The complete photographic film, composed of alternate layers of algin, gelatine
and sensitive gelatine emulsion, may he prepared and supported upon a temporary
paper basis and delivered to the consumer in that condition. This is termed a
stripping film inasmuch that the paper backing is detached from the film proper
at any convenient time, preferably after the photographic impression has been
obtained thereon, in this case the built-up film may be temporarily cemented to the
paper backing by a layer of soluble gelatine, gun, or other soluble cement, which
can be afterwards removed by treatment with warm water. A layer of soluble algin
may be used if preferred which would dissolve either in cold water or in the developer,
allowing the insoluble film to float off its paper backing.
5. By another method the sensitive material may be incorporated with the algin
and a thicker coating or series of coatings applied without any gelatine layers.
66
In the first three methods the algin sheet forms the support permanently for the
sensitive layer, and in the 4th method the paper backing forms the support until such
time as it is thought advisable to remove it. In this latter case the whole is termed
a stripping film." In the 5th method the algin support or basis also forms the
sensitive film itself. Although it is possible to coat the previousy prepared algin
skin with gelatine or sensitive emulsion without some kind of a temporary backing,
there are certain objections thereto, one of which is the tendency of the algin to
absorb a considerable portion of water from the gelatine, and so cause cockling and
unequal expansion together with difficulties in drying. This, in a measure, may be
overcome by stretching or straining the film till dry, or preparing it on a
instead.
rigid surface
In case the film is prepared on a flexible support, recourse may be had to rolling
or calendering the film between successive coatings in order to remove creases caused
by unequal expansion. I do not confine myself to any particular order or method of
applying the various coatings to produce the finished film, but in order to minimise
the herein before mentioned difficulties of unequal drying and shrinkage of the film,
I prefer the following or similar order:
Having obtained a suitable surface as a support I coat it first with gelatine, and
then dry; then coat with algin and dry; then immerse for a few minutes in the
calcium or other solution to render the algin insoluble, dry; and afterwards apply
the sensitive gelatine emulsion, then again dry.
If desired another coating of gelatine may be interposed between the algin and the
sensitive layer, and more than one layer of algin may be applied to secure the
requisite thickness.
In some cases I dispense with the several layers of gelatine and algin, and simply
coat the algin base direct with the sensitive emulsion.
For "stripping films" the soluble or cementive coating may be interposed between
the paper backing and the algin layer in lieu of the plain gelatine coating. In the
case of stripping films, where it is necessary to remove the soluble cementive coating
by warm or hot water, it is necessary to treat all the gelatine in the film proper with
chrome alum or its equivalent, to render the gelatine layers insoluble in the hot
water.
By using a sensitive photographic film strengthened by means of algin in the
manner herein described there is no necessity for afterwards strengthening the
finished negatives or photographic impressions by the addition of gelatine skins,

page_text: collodion, or the like, the finished negative being sufficiently strong and flexible
when completed, and much time saved. Also in this invention the algin expands
with the gelatine in the developing solution consequent upon the absorption of water
into the film. By carefully adjusting the thickness of the algin and gelatine so that
both shall absorb an equal amount of water, curling of the film when wet will be
avoided.
In producing a flexible film in bands or rolls suitable for use in the roller slide or
for other purposes, I adopt or use one or more of the hereinafter described methods
and appliances -
In the first case it is necessary to have a temporary support upon which to prepare
the film in a sufficiently long length, the said support to be capable of withstanding
the action of the solutions used to render the algin insoluble also, water, and increase
of temperature; to be flexible and yet rigid enough to counteract the cockling and
shrinkage of the film whilst the same is drying, and to allow the film to be easily
separated when required. For this purpose I prefer to employ the material technically
known as temporary support such as is used in the carbon process, and consisting of
paper sized and coated with an alkaline solution of lac and afterwards rolled and
waxed. Other materials may also be used, and I do not limit myself to any particular
material, but the following may be employed-Suite bly varnished or waxed paper;
paper or cloth prepared after the manner of oilcloth ; or leather cloth which has a
smooth surface.
Whatever material is used may be wound upon a stock spool, from which it is paid
off to the coating machine or machines, which apply the successive layers to its
surface the web is kept in a state of tension during the time that it is passing through
the coating machine. Suitable flanged guide rollers in connection with friction rollers,
either one or both sets being driven conduct the material to the coating trough in
which is contained the algin in à glutinous semi-liquid condition, in this the band is
passed over, under, against or around a coating roller which is immersed in the trough
or against a ductor roller revolving in contact with the immersion roller and against
guide rods or scrapers to regulate or gauge the thickness of the coating whereby the
band becomes coated with an even layer: In another method of coating which may
be adopted I place the stock spool in bearings over the immersion roller or ductor
roller and free to revolve in frictional contact therewith. As the band is drawn off it
becomes coated with the solution. Weights or springs may be added to keep the
spool in close contact and adjustable gauge rods or scrapers regulate the thickness of
the coating. After the algin coating the band may be allowed to pass through a
bath or trough containing the liquid for rendering the algin insoluble or if preferred
this operation may be left until after the film has been dried: the band is then run
between rubber squeezing rollers to get rid of most of the water and is afterwards
conducted by flanged guide rollers and friction rollers and travelling bands or tapes
to the drying apparatus which may be formed of the shape of long boxes or tunnels
surrounded or filled with hot air, water, steam or a solution of acetate of soda,
through or between which the band passes, or it may be formed of a number of drying.
cylinders around which the band is conducted or it may consist simply of an
apparatus for suspending or looping the moist band in a drying room to which hot
air is introduced by mechanical or other means, such as a fan blower or the temperature
otherwise raised to a suitable heat. In case the algin web has not been rendered
insoluble previously it must be dried without anything touching its surface, but in
case it should have been rendered insoluble through treatment in the manner aforesaid
the face of the algin web may come in contact with the drying cylinders and therefore
dry in much less time. The algin web after drying is ready for the coating of
gelatine or sensitive gelatine emulsion which is applied in a similar manner to the
algin as herein before described. The algin we may still remain attached to its
support whilst coating unless it is desired to coat both sides thereof in which case it is
stripped from the support and then passed through the coating apparatus and
afterwards dried. In the case of the gelatine or gelatine emulsion coating it is
necessary that nothing should come in contact with the face thereof so that the band

page_text: must be dried by passing over drying cylinders of such a temperature as not to melt
the gelatine, said band having its face outwards, or preferably in a drying room, the
algin coating may be dried at once by heated air of any temperature but the gelatine
coating must be allowed to thoroughly set and stiffen first, this operation may be
accellerated by allowing the band to travel through a shaft or chamber cooled
by ice or cold air supplied by fans, blowers or other means in the usual
manner: Heated air may then be used to hasten the drying of the moist gelatine
coatings.
In the case of a coating applied only to one surface of the band at a time I prefer
to let the band travel horizontally and perfectly level till the coating has set, but in
cases of coating both sides at once it should travel vertically. To keep the band from
curling at the edges before setting and whilst travelling horizontally I provide over-
lapping guides which just keep the edges flat or weighted rollers having collars or
flanges arranged to press on the edges of the band only.
The band if in one length may be suspended automatically or by hand in loops
either in the following or other suitable manner. In order that my invention may be
more clearly understood reference may be made to the sheet of drawings hereunto
annexed the coated part of the web is from W to W so that the edges of web are
gripped by the collars v and are uncoated: the rollers u and v revolve together either
by friction, spur wheels or other means and the two may be held close together by
springs or bands. I term each pair of rollers u and v, a looper.
The loopers slide loosely on a frame t and may be separated any distance apart from
each other, either by an attendant, or automatically by an endless chain or beit
having projections thereon at intervals so arranged as to move the loopers forward
at intervals.
The top roller of each looper is driven, either by endless band friction wheels, or
other equivalent or suitable mechanism and communicates motion to the corresponding
lower roller either by frictional contact as herein before described.
The motion of the band may be stopped at will by lifting the top rollers out of gear
with the bottom ones or by throwing the top rollers out of gear with the driving
mechanism. The web is passed between the loopers at one end of supporting frame
and the said loopers are afterwards separated the necessary distance apart as each loop
is formed. One looper or pair of rollers forms the suspending point for one loop. I
regulate the speed of the various parts so that the delivering of the web from
the coating to the drying machine shall be greater than the travel of the looped
and suspended web, and thus form the loops automatically at one end of the drying
machine.
So long as the loopers continue to revolve the web will have a continuous forward
motion and the constant change of its suspending points will tend to equalise the
drying of the coating and prevent streaking and also to prevent cockling and
especially curling up of the edges of the web and film, I so arrange the length of
travel and temperature of the drying room that the coating shall be dry and hard
before the web leaves the machine. In cases where the length is not sufficient I pass
the web under the drying machine and join the two ends of the coated web so as to
keep the whole continuously moving as one endless band. The following should be
mentioned the algin coating remains liquid until thoroughly dried by air or until
rendered insoluble in the manner herein before described. The gelatine coating ceases
to be liquid as soon as it is set by reduction of temperature. It will thus be seen
that in order to prevent streaking or running of the gelatine it is better that the
coated web should travel horizontally until set after which it may be placed or hung
in any position to dry and harden.
On the other hand the algin coating must be kept in motion and if suspended its
points of suspension must be constantly changing until it has dried, in order to ensure
an even coat on the web.
This is secured by suspending the web in the looping frame or drying machine
in a room supplied with heated air, which is previously filtered in the usual manner
to avoid dust.

page_text: The web whilst in the looping frame is kept constantly travelling in a forward
direction. In order to facilitate the drying I coat with a very concentrated solution
of the algin containing as little water as possible. If however the algin is rendered
insoluble or " set
as described, before leaving the coating machine, the web may be
dried whilst suspended without producing an unevenness of the coating, or it may be
dried by the drying cylinders, as the algin does not liquify by heat same
gelatine.
as
If the algin coat is dried first it must be rendered insoluble afterwards and
again dried.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents alginizing machine: a is the stock spool, the alginizing trough,
cimmersed coating roller, d guide rollers, e trough with liquid for rendering the
algin insoluble, squeezing rollers, the web, g gauge rod to regulate thickness of
coating, arrow indicates direction of web h to drying machine represented either
by Fig. 6 or Fig. 7.
Fig. 2 represents gelatinizing and emulsion coating machine. jis the stock spool,
h the web, k guide roller, 7 coating trough containing gelatine or sensitive
gelatine emulsion, m immersed coating roller, n levelling table for setting liquid
gelatine.
Figs. 3, 4 and 5 are modifications of Fig. 2. o is the doctor roller intermediate
between the immersion roller m and web to be coated. Fig. 6 is drying machine,
h is the web q guiding rollers, r drying cylinders, s receiving reel. Fig. 7. is looping
and drying frame, and Fig. 8. end view of same. z is the final receiving roller for
web h, is endless chain for forwarding loopers along frame t.
If the band should be divided into soveral shorter lengths, each one may be sus-
pended singly in a drying-apparatus, the said drying-apparatus or frame operating to
suspend the various lengths one behind the other, with suitable space between
theim and to push or move the suspenders one space forward for each separate length
automatically the several lengths may each have a weighted bar attached to bottom
end in order to keep the film stretched until dry and thus prevent cockling: or each
band may be separately stretched on a drying or stretching frame in any position,
vertical or otherwise, by attaching to suitable stretching mechanism.
The films may be prepared in sheets on rigid surfaces when desired by coating and
drying in the same manner as dry plates and afterwards stripped.
Films so prepared may be utilized in place of the ground glass focussing screen in
cameras. In the case of ordinary transparent films prepared according to this inven-
tion the film remains attached to its temporary support until it is finished and perfectly
dry after which it is stripped and is then ready to be packed for use or wound on
spools and forms a strong flexible material: To strip the film from its preparatory or
temporary support I separate a portion at one end by hand and then attach the
support to one reel and the film to another reel, and then cause both to wind in
opposite directions until the film and support are entirely separated throughout their
length each being wound on a separate reel.
By coating and drying both sides of the temporary support, either together or
separately, and afterwards stripping, two films may be prepared in the same
time as one. In the case of 66
stripping films " the paper backing upon which
they are prepared and sold to the consumer remains attached until the negative
has been obtained after which the stripping may be done in the usual manner.
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 what I
claim is
1st. In the production of a sensitive photographic film the use of algin, algulose,
alginates, or similar compounds or products such as are obtained from seaweed as the
base or support for a sensitive photographic film substantially as herein before
described said base being rendered insoluble during the manufacture.

page_text: 2nd. A complete sensitive photographic film consisting of one or more successive
layers of algin, gelatine and gelatine emulsion substantially as herein before
described.
3rd. In a sensitive photographic film such as herein before described the combina-
tion of the sensitive compound with the alginous base whereby the base and sensitive
surface are combined as a whole and afterwards rendered insoluble instead of
successively applied layers.
4th. A complete photographic film composed of an insoluble algin base and sensitive
gelatinous coating, the said film being attached to a temporary paper backing by a
layer of soluble cement, soluble in hot or cold water.or in the developer substantially
in the manner herein above described.
5th. A complete sensitive photographic film adapted alike either for negatives or
positives or transparencies and having colouring matter incorporated therewith when
required for special purposes substantially as herein before described.
6th. A complete photographic film consisting of layers of algin, gelatine and sen-
sitive gelatine emulsion, said film being of sufficient strength for ordinary photographic
purposes without after strengthening, substantially as herein before-described.
7th. The herein previously described ways of making the complete film and the
various order of coatings as also the several methods of applying the successive
order of coatings to counteract shrinkage and cockling of the film, and the regulated
thickness of successive coatings to secure equal expansion when film is wetted.
8th. The combination with alginates, algin, algulose, or similar alginous com-
pounds, of silicates and resins for a photographic film base substantially as described.
9th. A semi-translucent film such as described adapted to replace the ground glass
of a photographic camera and for similar purposes.
10th. In the manufacture of a photographic film in a web or continuous band, the
use of a temporary flexible support or web as also the various materials used for such
support or web, in the manner and for the purpose substantially as herein before
described.
11th. In the manufacture of a photographic film in the web the use of a temporary
support upon which the film may be prepared and dried and afterwards stripped
therefrom either when complete or prior to the application of the sensitive coating
or coatings, for the purpose and in the manner substantially as herein before
described.
12th. For the manufacture of a sensitive photographic web the use of an alginizing
machine consisting of suitable coating devices for applying a thin alginous layer
to a temporary support: a trough containing a liquid for rendering the said
coating insoluble; a stock spool carrying the web of temporary support and adapted
to feed the same to the coating devices, and suitably driven friction rollers provided
with flanges and collars to grip the edges only of the web and to draw the web
continuously forward from the spool and through or in contact with the coating
devices and afterward deliver the moving web to the drying machine for the purpose
and substantially in the manner herein described.
13th. In the manufacture of a sensitive photographic web, the use of a drying
apparatus adapted to receive the algin coated web from the alginizing machine and to
dry the same by contact with heated drying cylinders and to deliver the dried web to
a receiving reel for the purpose and in the manner substantially as herein before
described.
14th. In the manufacture of a sensitive photographic web the looping or drying
frame adapted to receive the coated web from the alginizing or gelatinizing machine
and operating to suspend the same in loops until dry.
15th. In the manufacture of a sensitive photographic film and for the purpose of
suspending a coated web, and for keeping the same in motion the use of the
loopers u and v and driving mechanism connected therewith, adapted to be thrown in
or out of motion at pleasure and operating to suspend the coated web in loops with
a space between each to keep the web in continuous motion; and to keep the sus
pending points of the coated web continually changing in order to insure an even

page_text: coating until the said coating is quite dry and to afterwards wind the same on to a
receiving reel.
16th. In a machine for applying coatings of liquid gelatine or sensitive gelatine
emulsion to a continuous web where the said web travels horizontally along the usual
form of levelling table the use of guards projecting over the edges of the horizontally
moving web to prevent cockling or curling up of the edges before the coating has
set, and also in addition or in lieu thereof the use of flanged rollers adapted to press
upon the edges of the web and to keep the same flat by reason of their weight sub-
stantially in the manner herein before described.
17th. The combination of parts and devices consisting of algin coating machine
insolublizing trough, flanged rollers feeding mechanism, drying cylinders reel, gelatine
coating trough, levelling table, tapes, feeding devices, looping and drying frame,
looping devices, driving mechanism, endless chain, gearing, and reel, forming a
complete apparatus for the manufacture of a sensitive photographic film in the web or
continuous bands substantially as herein before described.
18th. For the purpose of drying the photographic film in separate lengths or
bands, suspending the same in the manner described in a drying frame weighting the
bottom end of each length and successively pushing each length forward automatically
substantially as herein before described.
19th. The herein above described process of making two films on one support by
passing same successively through the various coating troughs suspending same
vertically and drying between each coating and afterwards stripping the two separate
films from their support.
20th. The herein above described method of separating or stripping the completed
film or films from the temporary support or web by separating the same at one end
attaching the film to one reel and the support to another and causing the reels to
revolve until the two webs are entirely separated from each other.
21st. The combined processes and arrangements for producing a transparent or
translucent sensitive photographic film in lengths or webs ready for use in the ordinary
forms of roller slides the said webs being of sufficient strength without the addition
of gelatine collodion or other backings at an after-part of the process and free from
the granularity frequently seen in films having a paper basis, substantially as herein
before described.
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