In a first step, odors are eliminated as the waste plastic undergoes mechanical pretreatment during shredding, washing and drying. Further odors can be removed from the shredded plastic in a silo using fresh air circulation.
The next, intensive devolatilization step, which markedly improves the recompound’s sensory quality, takes place during compounding in a ZSK twin screw extruder.
Following melting and intensive homogenization of the waste plastic in the ZSK extruder’s process section, volatile particles are degassed from the plastic melt in a highly energy efficient process. Using various technologies such vacuum devolatilizations, these dissolved gases are reliably removed from the product. This effect can be significantly intensified with the addition of liquid stripping agents.
Use of a ZS-EG side devolatilization unit provides a particularly effective and stable degassing process in the ZSK twin screw extruder, maximizing its deodorizing capabilities when high quantities of gas are present.
Coperion also offers post extrusion and pelletizing deodorization systems that play a further key role in improving waste plastic to the qualitative level of new plastic. They reliably remove any residual unpleasant odors from recycled plastic compounds. Hot air flows through the pellets in silos, diffusing even particularly stubborn, long-chain molecules from the compounds. For this step, Coperion has developed two different process solutions, depending upon the desired end product quality, the temperature it requires, residence time and quantity of air.
One method uses two silos – one to warm and deodorize the granulate and another to cool the granulate with cold air. In this process, comparatively little energy is needed to warm the product to the desired devolatilization temperature. Moreover, the cooler’s process heat can be used to pre-warm the pellets, increasing energy efficiency.
Alternatively, warming, degassing and cooling can take place in one silo by using two Bulk-X-Change heat exchangers. This solution is much more compact, requiring only one silo.
Our experts help you to identify the optimal degassing methods for your recycling process.
The focus is always on product quality, investment and subsequent operational costs. A variety of technologies are at your disposal in Coperion and Herbold Meckesheim Test Centers worldwide to test potential deodorization methods in advance.
| Versatile scope of application for recyclate and highest product quality |
| Highly efficient Coperion and Herbold Meckesheim solutions with maximum throughputs and reliability |
| Optimal solution for your application, taking investment and operating costs into account |
| Low maintenance and operating costs |
| Test Centers for recycling applications and mobile deodorization unit for tests at your location |
Coperion’s ZSK Recycling Extruders are suitable for intensive devolatilization of the melt. Volatile substances in small or large quantities can be reliably removed.
In some cases the devolatilization performance capability with conventional top vent extruder barrels can be limited. In this case the ZS-EG twin screw side devolatilization unit provides the solution.
Coperion offers different solutions for deodorization along the plastics recycling process. Odors can be removed from shredded plastic in a silo using fresh air circulation.
In addition Coperion offers post extrusion and pelletizing deodorization systems that play a further key role in improving waste plastic to the qualitative level of new plastic.
Our service structure consists of over 350 service engineers and technicians around the globe who not only look after your machines and systems but also after your business. They see themselves as partners who secure your future.
