Improved Process and Apparatus for Manufacturing Plastic Articles from Paper-pulp.
Year: 1893

page_text: Date of Application, 9th Mar., 1893-Accepted, 26th Aug., 1893
COMPLEIE DIEBUITIATION,
Improved Process and Apparatus for Manufacturing Plastic
Articles from Paper-pulp.
We, EMIL GELINEK and WILLIBALD GELINEK, of Komotau, Bohemia, in the
Empire of Austro-Hungary, Manufacturers, 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 material for making plastic articles in accordance with this invention
preferably consists of waste scraps of paper which are taken in a proportion of
say 40% and are converted into a plastic mass or pulp by the addition of
about 20% of size, glue or paste or vegetable gelatine, 20% of clay, and 20%
of flour. These materials are first roughly mixed together and then ground and
kneaded in special apparatus hereinafter to be described, on leaving which the mass
is ready for use in moulding articles of any desired description. This takes place
in the following manner :-
When the mass has been thoroughly kneaded and worked in the said apparatus, an
extension b is fitted to the tube or branch a through which the mass is to issue from
the apparatus. By this extension the body of the pulpy mass, which is first of circular
section, gradually assumes a rectangular shape in section, in which shape it escapes
from the mouth-piece or orifice of the extension b, the apparatus pressing it through
the said extension from which it is fed in the condition of a thin plate or sheet.
The plastic plates thus produced are placed in moulds F of preferably either
gypsum or metal (Figure 5 is a plan and Figure 6 a section of such a mould) and
pressed into the same by means of elastic dies P (Figure 6) more fully described
further on.
Owing to the pressure sustained by each of these dies it in its turn presses the
sheet or plate of paper-pulp (papier-maché) c tightly against all the surfaces of the
mould the forms and outlines of which are thus exactly reproduced. When the die
is removed a sheet of soaked, long-fibred paper is placed upon the papier-maché,
the die being once more applied in order to secure the paper-lining to the moulded
mass.
The moulded article thus obtained is then together with the mould placed in a
drying-chamber or oven and after being left there for a short time, it may be
removed from the mould the drying being if necessary completed simply by
exposure to the air.
The object of the lining with paper is in case of the moulded figure being broken
or cracked, to cause the long fibres of the said lining to prevent pieces of the
moulded article scaling or falling off and being lost in handling.
The arrangement of the flexible die is as follows,-
In order to obtain a clear reproduction or impression as it were of the mould, it
is necessary that the die employed should at every point be smaller than the mould
by the thickness of the plate to be moulded between the said die and mould. To
secure such a relative size of the two pieces, a layer of material of equal thickness
or depth throughout is placed against the walls or surfaces of the mould. The dry
unpolished gypsum mould is filled with thick clay-water which is first for a few
seconds stirred in a continuous manuer. The dry gypsum draws the water from the
clay-solution, and the clay which it contained in suspension now settles upon the
walls of the mould in the shape of an even and soft layer. The superfluous clay-
water is then thrown away and the clayey film allowed to dry somewhat. This
operation is repeated several times over until a film of the desired depth is obtained
in the mould, the space confined within this film indicating exactly the size which
the die working in the mould should present. The film of clay being polished over

page_text: and coated with oil, the die is formed therein by filling the empty space with
joiner's glue, which when it cools and become rigid constitutes the flexible o
elastic die.
To remove the layer of clay from the gypsum-mould, it is only necessary to allow
it to dry sufficiently for the clay to contract. When it does so it cracks and scales
off of its own accord or may be readily broken off. Figure 6 of the drawings shows
at c a section of an article in course of formation and of the space in which it is
enclosed and in which it takes up the position previously occupied by the film of
clay.
The apparatus employed in grinding and kneading the initial mixture is shown
in the accompanying drawings, in which Figure 1 is a side elevation and Figure 2 a
plan of the same, the lid or cover being removed in the latter view. Figure 3 is a
cross-section on a smaller scale. The apparatus mainly consists of two crushing or
kneading rollers A B provided on their surfaces with curved or spirally arranged
knife-edges or cutting blades M in such a manner that the blades or knives of one
roller engage in the grooves of the other. The rollers are retained by means of
their journals in the casing G which may be closed by means of a cover or door D
hinged at e. Motion is imparted to the mechanism by the shaft z¹ to which is fitted
a crank-handle. H is the shoot or hopper for the introduction of the material and
its conveyance to the rollers. The extension b of the outlet is formed of two parts
which are fitted to the outlet branch proper a and joined together by means of
Screws S. It will be seen that the outlet channel tapers or gradually becomes
narrower while at the same time it increases in width so that the issuing material
while it is being gradually flattened down above and below, is allowed to spread
sideways and to leave the apparatus in the shape of a flat rectangular plate or
sheet.
In Figure 1 the outlet-extension is shown partly in section and partly in
elevation.
Figure 2 is a section on lines x x x Figure 4, and Figure 4 is a view of the outlet
orifice of the said extension b.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is,
1. The process of manufacture of plastic articles from paper pulp consisting in
mixing approximately 40% of paper scraps, 20% of size glue or paste, 20% of
clay, and 20% of flour kneading and grinding the moist mixture in a suitable
machine and then allowing it to issue therefrom in the shape of a flat sheet or plate
which is placed into a gypsum mould and pressed into the same by means of an
elastic die made of glue upon the removal of which the moulded figure is backed
with soaked long-fibred paper and then once more pressed substantially as
described.
2. In carrying out the process as characterized in the first claim the method of
forming the glue-die P similar in shape to the mould but of less size the difference
being equal to the thickness or depth of the intervening sheet or plate to be
moulded the said method consisting in filling the dry unpolished gypsum mould as
many times with solution of clay as is necessary to form therein by the successive
deposits of clay a layer of the same thickness as that of the plates or sheets it is
intended to mould the layer of clay thus obtained being allowed to dry and being
eventually polished and oiled whereupon liquid joiner's glue is poured in and
allowed to cool and solidify in the mould thus forming an elastic die substantially as
described.
3. Apparatus suited for carrying out the process described in the preceding
claims consisting of two kneading rollers A B carried in the casing G the spiral
knives or blades of which are arranged to engage with each other respectively and
thus to work the pulp or mass supplied through the shoot or hopper H the said
mass being then conveyed to the outlet a and caused to leave the apparatus through

page_text: the outlet-extension b the outlet and extension being so arranged that the mass
which is at first discharged in the shape of a high and narrow body but finally
issues from the narrow orifice m of the outlet extension in a wide and thin
plate or sheet substantially as described and illustrated in the accompanying
drawings.
1 .
C
1 1000
W. P. THOMPSON & BOULT,
Of London, Liverpool, Manchester, and Nottingham,
Agents for the Applicants.