MATERIALS / RECYCLING PETplanet Insider Vol. 26 No. 04/25 www.petpla.net 38 Complex intermediate steps can be avoided with Plastcompactors from Herbold Meckesheim Agglomeration, desiccation, crystallisation Agglomeration systems are an 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 moulding machines. Plastcompactors from Herbold Meckesheim have been designed to save even complex intermediate steps 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 agglomerated recycled PET is already partially crystallised. All in all, the material is much easier to handle and therefore more suitable for further processing steps in preform injection moulding machines or film extruders with gravimetric dosing, says Herbold Meckesheim. 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 disks that are equipped with bolt-on and easily replaceable kneading bars. A continuously adjustable feeding screw constantly conveys granulated material from the buffer silo into the working zone through the centre 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 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 fibres, 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. 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. Subsequent agglomeration, in conjunction with a secondary granulator and a classifier, can achieve residual humidity of less than one percent. Likewise, various additives such as lubricants, plasticisers or colour pigments can be incorporated using special dosing units on the feeding screw. Compounding or the recrystallisation of PET flakes are further fields of application. The HV 70 from Herbold Meckesheim is also claimed to combine 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 solution has been modified. In combination with improved automatisation of the compactor and a more compact design, manual interventions during operation are less frequently required, offering customers a higher degree of operational reliability. In addition, the silo and the feeding device have been optimised in such a way that even more complex materials with the lowest bulk densities and the most difficult flow characteristics can be handled safely. www.herbold.com Plastcompactors process the feedstock in continuous operation between a rotating and a stationary disk. (Photos: Herbold Meckesheim) The HV 70 Plastcompactor (Picture: Herbold Meckesheim) Agglomeration plant for fibres, fines, tapes, foams, films, powders or shavings.
RkJQdWJsaXNoZXIy NTY0MjI=