mprovements in and in Apparatus for the Treatment of Liquid Gelatine or Glue for the Ultimate Production of Plates or Sheets of such.
Year: 1892

page_text: COMPLETE SPECIFICATION.
mprovements in and in Apparatus for the Treatment of Liquid
Gelatine or Glue for the Ultimate Production of Plates or Sheets
of such.
A communication by FRIEDRICH AUGUST WOLFF, of Heilbronn, in the
Kingdom of Würtemberg, Germany, Manufacturer.
I, WILLIAM PHILLIPS THOMPSON F.C.S., M.1.M.E. of the Agency for
Foreign Patent Solicitors, 6 Lord Street, Liverpool and 6, Bank Street,
Manchester, both in the County of Lancaster and 323 High Holborn, in the
County of Middlesex, Civil Engineer, do hereby declare the nature of this
nvention and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:—
This invention has for its object a process, and the apparatus necessary therefor,
for treating gelatine or glue, commencing with the same in a liquid condition and
ending with the drying of the finished thin plates. In order to allow of the
difference being better understood between the processes and the necessary
apparatus therefor, hitherto employed, and this new process and its apparatus, it
may be best to first briefly describe the processes hitherto employed together with
their disadvantages.
One of the best known and most generally used is that of pouring the heated
liquid gelatine or glue, into open moulds and allowing it to remain therein until it
is of sufficient consistency to be cut up into plates by means of a cutting apparatus.
These plates are then placed separately on drying frames, and the latter are
conveyed into the drying chamber, from whence the plates emerge quite ready for
transport.
The difficulties existing in this process consist essentially in the fact that even in
cold weather the setting of the gelatine in the moulds proceeds very slowly, and in
hot weather, on the other hand, it takes place so slowly that there always exists a
danger of rapid putrefaction, in other words, entire destruction, (a speedy
formation of fungus takes place, as gelatine, as is well known, forms the best
propagating medium for bacilli).
The manipulation of the congealed blocks removed from the moulds into thin
plates creates the further difficulty that a number of these plates are always
destroyed in the cutting, and that, further, even when they are being placed on the
drying frame, which must be done separately and by hand, a large number is torn,
which loss becomes greate: the warmer the temperature, in so much that the plates
frequently melt in the hand, and become stinking, that is to say, entirely unuseable.
All attempts to remove these drawbacks have only been of very small value, so
generally restricted, as the losses
much so that the manufacture in hot weather
are frequently enormous.
A further process, which however does not appear to have gone beyond an
unsuccessful experiment, is in causing a slowly revolving roller heated with steam
to dip into a vessel containing the liquid mass, and in drying on the roller the mass
remaining adherent to the periphery, and in then removing the same before the
roller again dips into the vessel. This idea was a good one, but no gelatinous mass
to speak of remained adherent, as liquids generally have no tendency to run up hill,
and the adhesion was so small that almost nothing remained adhering especially as
the roller rotated extremely slowly so that the drying might be effected. The
drying itself, by means of steam, was found to be unsuitable, and, on account of
these unfavourable circumstances, this process will hardly be made use of in
practice

page_text: .
This new process consists essentially in allowing the liquid gelatine or glue to
flow continuously on to a channel, composed of an endless band moving slowly
forward, and lying horizontally at the top, into which the mass is auto-
matically distributed, and forms a continuous strip which gradually changes
from a liquid condition to a solid one. This transformation is brought about by
refrigeration, cooled air being drawn or forced through air passages surrounding
the endless band, in an opposite direction to that in which the latter is travelling,
by means of an exhaust fan or other suitable apparatus, in such a way that the
mass lying on the travelling band is constantly surrounded with cold air and thus
is rapidly cooled and sets. In this condition, the strip of gelatine or glue is
removed from the endless band by means of a scraper resting against the band and
conducted away by another travelling web, and, whilst continuously travelling
along with the same, is cut into given lengths by means of a suitable cutting
apparatus, which lengths are then conveyed to the drying frames and then dried in
the drying chamber.
When dried, the now thoroughly dry strips are cut into small pieces and then
packed for delivery.
No manual labour is required to convert the gelatinous or gluey mass from its
liquid condition into solid strips in the drying chamber.
The strips need only be handled after they are completely dried, and are to be
removed from the drying frame and cut into smaller pieces, in other words, any
danger of the gelatine or glue being dirtied or of the congealed plates being injured
is obviated.
The thickness of the gelatine or glue plates or sheets may be exactly determined
by adjusting the flow of the liquid on to the endless channel, or by altering the
speed of the same, in such a way that the thinnest plates may be produced without
any difficulty. A period of time of from 10 to 20 minutes is requisite, according to the
thickness of these plates or to the degree of temperature of the cold air drawn over
them, for converting the liquid mass into a condition of consistency sufficient to
allow of its being conveyed in thin strips into the drying chamber. Thus any fear
of a growth of fungus or of its becoming putrescent is removed.
An apparatus for carrying out the above described process is shown on the
accompanying sheet of illustrative drawings:
Figure 1 shows a longitudinal section ;
Figure 2 a cross section; and
Figure 3 a plan ; whilst
Figure 4, drawn on a larger scale still, represents a cross section through the
endless band which forms the moving channel and the air passages surrounding the
same. The liquid mass of gelatine or glue flows from the reservoir A, through
pipe a and cock a¹ on to the level, continuously moving channel B, which is
preferably made of oil-cloth on account of its smoothness and non-adhesiveness, in
such a way that it rests on an endless and also moving web C, which runs over 2
rollers E' and E³, and there are provided, at suitable distances from one another on
the flat underside, cylindrical guide rollers c for the purpose of supporting the web.
The oil-cloth band B rubs with both edges on the inclined plates bb, whereby the
former are somewhat bent up, and form a continuous channel from which any
escape of the liquid other than longitudinally along the channel B is impossible,
and the quantity flowing out is also so regulated that the mass has a depth of about
2 millimetres.
On the underside, the endless band C and the channel B are twice turned
similarly to a crossed belt in such a way that the mass of gelatine or glue, which
in the meantime has become set, again lies on the upper side between the turning
points, and the web C may also be again supported by rollers c c.
Both air passages F and F which enclose the upper and lower parts of B and C
are connected by means of the passages and with an exhaust fan or other
cold supply, so that, by the motion of the exhaust fan, cold air is drawn through
the passages fF' and F', that is to say, in a reverse direction to the movement of

page_text: the mass of gelatine or glue, and thereby the cooling of the thin continuous strip
is brought about extremely rapidly.
The steam from the warm liquid issuing at a¹ is also directly drawn off by the
exhaust apparatus, and discharged into the outer air. The strips of gelatine or
glue, which bave become set, are then conveyed by means of the scraper e from
the channel B to the endless web i, running over the rollers J, and there cut into
strips by means of the revolving knife G. These strips are further conveyed
to the drying frames R, which are also moved forward by travelling belts k. It
must be observed that it is necessary that the speed of B, i and k must be exactly
the same, so that no forcible tearing of the gelatine or glue shall take place.
If it be undesirable to have a double turning of the endless channel B and
band C, this can also be replaced by a suitable extension of the apparatus and the
insertion of a removing apparatus e Ii Rk on the roller E' instead of E'.
Two or more of the above described apparatus may also be arranged beside
one another, and be fed with liquid from a common reservoir.
Fans, bellows or other known suitable apparatus may also naturally be employed
for passing cooled air through the passages enclosing the endless channel B.
The arrangement for removing the solidified strip of gelatine or glue from the
endless web B may also be modified in various ways without thereby altering in
anything the essential part of the invention.
The advantages of this invention, that is to say, the rapid conversion of the liquid
gelatine or glue into thin plates or sheets of sufficient consistency to allow of their
being immediately dried, are so self-evident to practical men that no further
enumeration of the same is necessary. Only one further advantage will be named,
namely, that in consequence of the shaped section of the channel B the strips
of gelatine are thinner at the edges, that is to say, the edges run to a point, and,
as the cutting of the strips of gelatine or glue into small plates only takes place
when the drying is completely accomplished, the cut edges also do not become
thicker than the plates themselves, and thereby the swollen edges, as in the plates
or sheets hitherto produced, are done away with.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. The improvements in the treatment of liquid gelatine or glue for the ultimate
production of plates or sheets of such, which consist in allowing the liquid
gelatine, or glue, to flow ou to an endless channel, horizontal at top, and actuated
with a slow continuous motion, and attaining therein, by means of air passages
surrounding the same, through which a cooling medium is drawn or forced, such a
consistency that the strips may be removed from the endless channel and conveyed
direct to the drying room, substantially as hereinbefore described.
2. The improvements in apparatus for carrying out the process described in
Claim 1, which consists in the employment of an endless band (C) running over
rollers (E1 and E2) and drawn against a second baud (preferably of oil-cloth),
which has its edges bent somewhat upwards preferably by two inclined strips >>, so
as to prevent the liquid gelatine or glue travelling thereon from running over,
whilst passages 2 F F and f' are provided, through which a cooling medium is
caused to pass in an opposite direction to that in which the belts B and C are
travelling, and brings the at first liquid strip to such a consistency that it may be
reinoved by means of any suitable apparatus from the endless band and conveyed
direct to the drying room, all substantially as hereinbefore described and shown.
Dated this 1st day of April 1802
WM. P. THOMPSON & Co.,
Agents for the Applicant.