Solid material comminution or disintegration – Processes – With heating or cooling of material
Patent
1995-01-20
1996-08-27
Husar, John
Solid material comminution or disintegration
Processes
With heating or cooling of material
241 2418, 241 65, 241 79, 241236, 241 2428, B02C 1806, B02C 1818, B02C 1900
Patent
active
055492509
DESCRIPTION:
BRIEF SUMMARY
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a national phase of PCT/EP93/01583 filed 22 Jun. 1993 and based upon German national application P 42 20 666.9 filed 24 Jun. 1992 and P 43 18 839.7 filed 7 Jun. 1993 under the International Convention.
FIELD OF THE INVENTION
The invention relates to a process for sorting thermoplastic materials from a mixed stream of materials, whereby the thermoplastic material to be separated is heated by convection or radiant heat to the range of its softening point and then taken together with the other material of the mixture to a grinding device. The invention relates further to a device for carrying out the process, having a transport and a heating installation and a grinding device arranged downstream thereof.
From DE-41 12 179 C1 a process is known for the clear separation of shaped thermoplastic parts of various origin. At a certain temperature or temperature range, each thermoplastic synthetic material passes from its solid state into the plastic state. The known process proposes to heat the various shaped parts without grinding through direct or indirect heating to a temperature which corresponds to the softening temperature of those shaped parts with the comparatively lowest softening temperature. The shaped parts are treated at that temperature until under the influence of gravity they lose their initial shape as much as possible through volume reduction. Subsequently the shaped parts which have been reshaped this way are separated from the shaped parts which have essentially kept their shape, by being sorted out, based on their different shape, while they are transported on a roller conveyor, whereby the respective reshaped parts fall through the gaps between the rollers and are removed from there as a homogeneous fraction., while the rest of the parts, which have remained mostly unchanged in shape are removed by the roller conveyor in the travel direction.
On the one hand the known process has a low yield, because the reshaping of for instance a hollow body into a flat state requires longer heating. The process is also limited to a narrowly defined spectrum of shaped parts such as cups, bowls, receptacles or the like, because objects with closed shapes such as bottles, containers, pipes or the like can be converted only with great difficulty into a clearly different shape. The sorting by shape requires on the one hand a special detection and logistics for waste products, on the other hand the latter can be non-destructively cleaned only with an unjustifiably high technical effort. However a cleaning is necessary, because particularly the residual humidity has a negative influence on the thermal treatment and thereby on the results of the process. Besides the sorting operation taking place after the thermal treatment relies purely on a sorting by shape.
OBJECT OF THE INVENTION
It is the object of the invention to provide a process and a device for the sorting of thermoplastic materials from a mixed stream which can overcome the above-mentioned drawbacks, difficulties and technical limits and which can make possible unobjectionable sorting based on different thermal softening behavior of the thermoplastic materials, with a high yield and precise selectivity.
SUMMARY OF THE INVENTION
In a process of the above-mentioned kind the invention solves this problem in that, based on the particle size and the elastic behavior of the softened thermoplastic material on the one hand and of the other materials in the mixture, on the other hand, only the softened thermoplastic materials are selectively picked out and ground by the grinding device, while the other materials in the mixture pass through the feeding and collecting area of the grinding device and are separately removed in an unground state.
This way the precise sorting according to indication of the softening point of a certain type of thermoplastic material due to the selective behavior of a grinding device is advantageously performed on a technical scale which makes possible a rational, econ
REFERENCES:
patent: 3960335 (1976-06-01), Haberle
patent: 4098463 (1978-07-01), Lowry
patent: 5115987 (1992-05-01), Mithal
Dubno Herbert
Husar John
LandOfFree
Process and device for sorting thermoplastic materials from a mi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process and device for sorting thermoplastic materials from a mi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process and device for sorting thermoplastic materials from a mi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1050843