Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
The present invention relates to an apparatus
or reclaiming plastic.
During the mass production of small plastic
components, such as switch housings, switches, and
many other accessories, which are used, for example,
in the motor vehicle industry, a not inconsiderable
amount of plastic waste is produced during the
manufacture, for example with the use of a known
plastic injection molding process. In principle,
this plastic waste represents a valuable source of
raw material, that up to now has been treated as
waste or scrap, and has either been dumped or
burned.
However, large vehicle components, for example
the bumpers at the front and rear of a vehicle, have
increasingly been made of plastie instead of metal.
These plastic eomponents, in eontrast, for example,
to an automobile body, which is generally made of
metal, are not subject to natural eorrosion or an
environmentally-related abrasion; rather, these
plastic components generally remain unchanged during
the normal service life of a vehicle. These large
plastic components in the vehicle industry, and also
in other manufacturing areas for other components,
increasingly represent a significant disposal
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problem.
In principle, not only plastic waste that is
produced during the manufacture of plastic
components, but also for plastic articles that are
no longer used, represent a significant source of
raw material that up to now was, to a large extent,
not used, since on the one hand the necessity for
reuse was not recognized, and on the other hand
adequate methods and apparatus were not available in
order to be able to economically convert the plastic
waste into a reusable form.
It is therefore an object of the present
invention to provide an apparatus with which, in an
economical manner, plastic waste can be converted
into a form that permits an unlimited reuse as
plastic raw material and that is straightforward in
construction and easy and economical to produce.
Brief Description of the Drawings
This object, and other ob;ects and advan~ages
of the present invention, will appear more clearly
from the following specification in conjunction with
the accompanying schematic drawings, in which:
Fig. 1 is a cross-sectional view of a
first exemplary embodiment of the
inventive apparatus for reclaiming
plastic, in which merely the
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compaction cylinder is provided
with heating mechanisms; and
Fig. 2 is a cross-sectional view of a
second exemplary embodiment of the
inventive apparatus for reclaiming
plastic, with the plastic feed zone
to the feed mechanism additionally
being provided with a heating
mechanism.
Summary of the Invention
The apparatus of the present invention
comprises: a feed mechanism for receiving plastlc
waste and conveying it further; a compaction
mechanism for receiving plastic waste from the feed
mechanism, with the compaction mechanism being
provided with means to compact the plastic waste;
first heating means for supplying heat to the
compaction mechanism to warm plastic waste located
therein; and a perforated disk disposed at a
discharge location of the compaction mechanism for
the discharge of compacted and heated-up plastic
waste therefrom as reclaimed plastic.
The advantage of the inventive apparatus is
essentially that in principle a first reduction in
volume of the plastic waste can take place via a
preliminary reduction in size by the feed mechanism,
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that subsequently the precompacted plastic waste can
be further compacted by suitable means, and that in
so doing the compacted plastic waste is heated to
such an extent that it can pass through a perforated
disk in the form of individual plastic strands that
permit a further processing as reclaimed plastic
that can be used as raw material.
Pursuant to one advantageous specific
embodiment of the present invention, a feed
mechanism is in the form of a driven worm conveyer,
and is provided with a hopper for the supply o
plastic waste. The hopper is oriented essentially
perpendicular to the axis of rotation of the worm
conveyer, so that any plastic waste that is
introduced into the hopper, and that possibly has
been previously mechanically reduced in size to
pieces that can be accommodated, can be taken along
by the worm conveyer, can be precompacted, and can
subsequently be fed to the compaction mechanism.
In order to make the plastic waste parts that
are fed via the hopper to the feed mechanism, and
that can have a considerable material-related
strength at normal temperature, more precompactable
and easier to transport through the worm conveyer,
it is proposed pursuant to another advantageous
specific embodiment of the inventive apparatus, that
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the feed mechanism be provided with a heating
mechanism for supplying heat thereto; this heating
mechanism can, for example, be disposed about that
portion of the hopper where it opens into the worm
conveyer.
The compaction mechanism itself preferably
includes a cylinder and a piston that is movably
disposed therein, so that the precompacted plastic
waste coming from the worm conveyer can be compacted
still further.
Compaction of the plastic waste in the
compaction mechanism is effected by moving the
piston, advantageously via any desirable pressure
medium, in the direction toward the perforated disk.
The pressure medium can be a gas, for example air,
or also a hydraulic fluid. Furthermore, it is
similarly conceivable to move the piston in the
direction of the perforated disk, and back, via, or
example, a threaded spindle that is suitably
connected to the piston.
During actuation of the piston via a pressure
medium, the piston can preferably be conveyed via
spring action into an end position that is remote
from the perforated disk. However, it is also
conceivable to convey the piston into the starting
or end position, after compaction has been carried
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out, via a pressure medium that is introduced into
that space of the cylinder in which the compaction
of the plastic waste took place.
In order to heat the cylinder, and hence the
plastic waste, and to convert the plastic waste as
much as is possible into a viscous state for the
subsequent compaction, after the plastic waste, that
has been precompacted by the worm conveyer and has
possibly already been preheated, leaves the feed
mechanism, the compaction mechanism advantageously
includes a second heating means that is essentially
disposed in that region where the feed mechanism
opens out or discharges into the compaction
mechanism. This embodiment of the inventive
apparatus furthermore permit~ a more uniform hea~ing
of that portion of the cylinder that is primarily
used to carry out the final compaction process of
the plastic waste.
Finally, the apparatus is preferably provided
on the downstream side of the perforated disk with
a device for reducing the size of the reclaimed
plastic. Thus, for example, the length of the
plastic strands that leave the perforated disk could
be cut to any desired size so that it is precut to
a suitable length for some specialized use.
The size-reducing mechanism is finally
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advantageously formed by a motor-driven rotating
cutting means, such as a blade. However, it should
be noted that the size-reducing mechanism can also
be formed by any other suitable size-reducing means.
Further specific features of the present
invention will be described in detail subse~uently.
Description of Preferred Embodiments
Referring now to the drawings in detail, the
apparatus 10 essentially comprises a feed mechanism
11 and a compaction mechanism 13. The feed
mechanism 11 is provided with a discharge opening 24
to permit entry of precompacted plastic waste 12
into the compaction mechanism 13.
In the illustrated embodiment, the feed
mechanism 11 essentially comprises a cylindrical
casing portion in which is disposed a worm conveyer
17 of known construction that rotates about a shaft.
The worm conveyer 17 is driven about its shaft in a
known manner by means of a motor, for example an
electric motor, that is connected to the conveyer
shaft. Mounted above the casing of the eed
mechanism 11, essentially perpendicular to the axis
of rotation of the worm conveyer 17, is a hopper 18
through which the plastic waste 12 can be fed to the
worm conveyer 17.
The compaction mechanism 13 essentially
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comprises a cylinder 20, the casing of which is
connected essentially perpendicularly to the feed
mechanism 11. Provided at a suitable location on
the side of the cylinder 20 is a hole that forms the
aforementioned discharge opening 24 of the feed
mechanism 11. One end of the cylinder 20, namely
the upper end with the vertical orientation of the
cylinder 20 as illustrated in the drawings, is
provided with a closure means 27 in the form of a
cover, with the vertically lower end of the cylinder
20 being provided with a conically tapered portion
28 of the cylinder body. Disposed at that part of
the conically tapered portion 28 that has the
smallest diameter is a perorated disk 15, which
can, for example, be interchangeable.
Disposed essentially parallel to and at a
distance from the perforated disk 15 in the
direction of the discharge of the reclaimed plastic
16 from the apparatus 10 is a size-reducing
mechanism 25 that is driven by a motor, for example
an electric motor. The portion of the apparatus 10
about the perforated disk 15, in an extension of the
cylinder 20, is formed by a tubular portion 29, at
the discharge end of which is disposed an end flange
30 about which rotates a cutting means 26, for
example a blade, that is driven by the size-reducing
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mechanism 25.
Disposed in the cylinder 20 is a piston 21 that
can move back and forth, i.e. in the illustrated
embodiment can move up and down in a vertical
direction. By means of a piston rod 31 that is
connected to the piston 21, the piston is guided at
least partially in the upper closure means 27 of the
cylinder 20. By means of a connection 32 in the
closure means 27, a pressure medium, for example a
gas or a hydraulic fluid, can be introduced into the
first cylinder space 33, so that the piston 21 can
move in the direction of the arrow 35 against the
force of a spring 22. I the supply o a pressure
medium to the first cylinder space 33 is
interrupted, and the pressure medium disposed in
this cylinder space is again withdrawn via the
connection 32, the piston 21 again reaches its
vertically upper position in the cylinder 20 under
the influence of the spring 22.
A first heating mechanism 14, and a second
heating mechanism 23 that is spaced therefrom, are
provided about that portion of the cylinder 20 that
forms a lower portion thereof when the cylinder 20
has a vertical orientation; these heating mechanisms
14, 23 can, for example, encircle the cylinder 20.
The heating mechanisms 14 and 23 can, for example,
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be electrically heated, although it is also
conceivable to use any other available heat source
therefore, such as waste heat.
Disposed about that portion of the hopper 18
that forms a lower portion thereof when the
apparatus 10 has a vertical orientation, is a
similar heating mechanism 19 that can similarly be
operated either electrically or with any other
energy that is available.
During the production of reclaimed plastic 16,
the plastic waste 12 is first fed to the apparatus
10 via the hopper 18. In this connection, the
plastic waste 12 can appropriately have been
previously reduced in size, either mechanically or
in any other suitable manner, to such an extent that
the plastic waste can be received by the hopper 18.
By means of a heating mechanism 19, which can be
provided in the lower region of the hopper, the
supplied plastic waste 12 is heated up and is
subsequently precompacted via the motor-driven worm
conveyer 17 and is conveyed to the discharge opening
24 in the cylinder 20. The precompacted and heated-
up plastic waste 12 then drops into the lower space
34 of the cylinder 20, where it is further heated up
by the heating mechanism 14; in this connection, as
previously mentioned, a further heating mechanism
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23 can be provided in the immediate vicinity of the
discharge opening 24.
After a sufficient quantity of precompacted and
preheated plastic waste 12 is present in the lower
portion of the cylinder 20, the piston 21, as
described above, is moved downwardly via a pressure
medium in the direction o~ the arrow 35, thus
compacting the plastic waste 12 located in the
second cylinder space 34 in a designated manner; at
the same time, the plastic waste 12 is heated up
still further by the heating mechanisms 23 and 14.
The viscous, precompacted plastic waste material 12
is guided via the conical tapered portion 28 of the
cylinder 20 to the perforated disk 15, through which
the plastic material is pressed. The individual
strands of reclaimed plastic 16 that leave the
perorated disk 15 can then be cut by the size-
reducing mechaniæm 25 to a specific suitable length,
depending upon need and application.
It should be noted that the feed cycle of
plastic waste 12 to the apparatus 10, and the
compacting cycle via the piston 21, can be
automatically controlled in a suitable manner, so
that in principle the apparatus 10 can be entirely
automatically operated.
The present invention is, of course, in no way
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restricted to the specific disclosure of the
specification and drawings, but also encompasses any
modifications within the scope o the appended
claims.
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