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Plastic Recycling Process Made Simple for Circular Economy

2022-09-30 | Technical Blog | By Resul Gökpınar |

In response to the emerging demand for the recycling plastic wastes such as PP raffia, woven and rigid plastics, POLYSTAR has developed the shredder integrated plastic granulator for plastic producers and recyclers. It aims to provide a simple plastic recycling process to help producer to complete their circular economy cycle.

Repro-One plastic granulator is highly flexible with integration of intelligent systems to increase process automation. Besides it combines three main plastic recycling processes into one single machine (Shredding + Extrusion + Pelletizing).

1.Shredding Process

Generally, hard to crush and bigger sized waste plastics are first pre-crushed with plastic crushing machines. In contrast, by the Repro-One shredder integrated plastic granulator the materials can be directly fed into the machine without pre-crushing.

Just after shredding process with the single shaft shredder, the materials immediately transferred to the recycling extruder. Thus, the consistent feeding, which is one of the prerequisites for a higher output, is easier to achieve.

Integrated single-shaft shredder process the waste plastic materials into smaller pieces in a short time and at a low process temperature. This precise and short time shredding process results in minimal degradation of the chemical structures of the materials. This increases the reusability and quality of the final pellets.

2.Plastic Extrusion Process - Efficient Degassing and Filtration

After shredding, the waste material is directly transferred to the recycling extruder, where it is melted at the appropriate temperature (plasticization) and take a liquid form (plastic melt). During the extrusion process, the plastic melt passes through the degassing and filtration units and is purified from the contamination and gases it contains.
- Degassing unit
  
  The humidity and ink especially the printed and humid materials contain, turn into gas in the plasticization. Effective degassing for such materials prevents the air bubble formation inside the final pellets.
  
  The optimal screw design and the double-vented degasification together eliminate the problem of material leakage from the the ventilation window. Thus, the machine can work at full speed.
- Filtration unit
  
  Dual piston filter system allows filter screen changing while the machine is running and prevents material waste. Avoiding loss of time and efficiency caused by machine down times.
  
  In order to further increase automation in the recycling process, we have also been offered a back-flush filter system that automatically performs melt waste discharging and reduces the cost of screen replacement operation.

3.Pelletizing Process – Uniform Sized Pellets

After the plastic shredder and extruder, the next step is the plastic pelletizing process where the plastic melt is cut into pellet shapes. The plastic pelletizing system is one of the most important parts of the plastic granulator machines. POLYSTAR focuses on a fully automated hot die face cutting pelletizing system (water ring pelletizer) to increase the output and pellets quality.

( Hot die face cutting pelletizing system )

Automatic pelletizing knife speed adjustment

The speed of the pelletizing knives is synchronized with the die head pressure, ensuring that the granules are always cut to the same shape and size. Moreover, this automation also prevents the pellets of the materials with high melting index (such as PP) from sticking together.

Automatic pelletizing knife pressure adjustment

It ensures that the pressure of pelletizing knives to the die head remains constant. As a result, it ensures stable production and prevents material loss. Besides, the knives and die head lifespan is extended. Knives are also designed to be changed easily, resulting shorter machine downtime.

Plastic Recycling Process Automation with Intelligent Systems

Regarding to the circular economy sustainability, Repro-One shredder integrated plastic granulator machine is designed for producing high-reusability pellets with an uninterrupted operation. For that, the plastic granulator not only combines shredding, extrusion and pelletizing processes into a single machine, but also ensures these systems works in a harmony through automation systems.

In addition, the material feeding speed to the shredder is also automatically controlled. It results with the consistent feeding for higher pellets output.

( PLC Control System )

In accordance with the development of Industry 4.0, the customers can also upgrade the standard control panel to the PLC control system. This system has a user-friendly HMI (Human-Machine Interface), which significantly shortens the learning curve for operators. PLC control system can perform many different tasks including online troubleshooting, big data collection and analysis, automatic pre-heating and parameter optimization with cloud IP control.

Conclusion

As global environmental protection awareness continues to grow, the circular economy sustainability is becoming a very important trend in the sector. Recycling is an important part of this cycle and should be encouraged more. POLYSTAR, therefore designs not only efficient and energy-saving machines, but also the plastic granulators that are easy to use and can process a wide range of plastic materials.

For this reason, Repro-One shredder integrated plastic granulator is especially preferred by our customers who want to recycle different materials such as PP raffia, woven, jumbo bags, films, start-up lumps, uncrushed hard plastics, and many in one step. You can also contact us to get more information about plastic granulators and find a suitable one for yourself.