Agglomeration systems are a highly efficient solution that is in constant demand for achieving free-flowing regrind with a high bulk density that can be directly processed in extruders or injection molding machines. And with Plastcompactors from Herbold Meckesheim, even complex intermediate steps can be saved when reprocessing recycled PET: The agglomerate does not require any special silos for storage as it can be easily discharged and conveyed, unlike classic flakes. In addition, the recycled PET is already partially crystallized through the agglomeration.
All in all, the material is much easier to handle and therefore more suitable for further processing steps in preform injection molding machines or film extruders with gravimetric dosing. Furthermore, the specific energy requirement for the extrusion of compacted plastics is lower and the throughput higher.
The Plastcompactor HV 70 is the most powerful of the series from Herbold Meckesheim. It compresses the feedstock in continuous operation between a rotating and a stationary disk that are equipped with bolt-on and easily replaceable kneading bars. A stepless adjustable feeding screw constantly conveys granulated material from the buffer silo into the working zone through the center of the stator disk in a controlled manner. Since the rapidly warmed material leaves the compacting zone within fractions of a second, the thermal impact on the plastic is extremely low. The process is regulated by two degrees of freedom – the speed of the screw and the distance between the discs.
HV Plastcompactors can be used to agglomerate a wide variety of materials into products with a high bulk density: thermoplastics such as fibers, fines, tapes, foams, stretch or thin films, powders or shavings, as well as plastics that are difficult to convey, store or mix. In particular with stretch films or foams, adequate drying by mechanical or thermal means would only be possible with an immense use of energy. This is where a Plastcompactor is the solution of choice.
Moreover, the compactors from Herbold Meckesheim are often installed downstream of washing lines: Here, the damp material is heated in the compacting zone to such an extent that the moisture escapes. With subsequent agglomeration – in conjunction with a secondary granulator and a classifier – residual humidity of less than one percent is achievable. Likewise, various additives such as lubricants, plasticizers or color pigments can be intensively incorporated using special dosing units on the feeding screw. Compounding or the recrystallization of PET flakes are further fields of application.
The HV 70 from Herbold Meckesheim also combines high throughput with low maintenance costs and a fully automatic control system in which settings for different infeed materials can be recorded. And thanks to the performance and temperature monitoring, the process is controlled in such a way that only minimal personnel deployment is necessary.
In the course of the latest enhancements, the disk geometry of the Plastcompactor HV 70 has been significantly modified. In combination with improved automatization of the compactor and a more compact design, manual interventions during operation are even less frequently required, offering customers a higher degree of operational reliability.
On the other hand, the silo and the feeding device have been optimized in such a way that even more complex materials with the lowest bulk densities and the most difficult flow characteristics can now be handled safely. This opens up further fields of application for the HV 70 from Herbold Meckesheim.