Chemical recycling
Efficient plastics processing before chemical recycling
The recycling of plastics is becoming increasingly important in the context of chemical recycling – also known as advanced recycling. In order to prepare plastics for these thermo- or solvent-based processes, targeted and high-quality mechanical processing is essential. WIPA Werkzeug- und Maschinenbau GmbH offers customized machine and system solutions for this purpose, which are specially designed to meet the requirements prior to chemical recycling.
The central process steps in pre-processing are agglomeration, washing and dry cleaning, which is particularly resource-efficient. These not only ensure homogeneous material quality, but also minimize impurities that could impair subsequent chemical processes or make them uneconomical.
Dry mechanical cleaning
Dry mechanical cleaning – saving resources, increasing efficiencyThe dry mechanical cleaning approach developed by WiPa is particularly innovative. This method replaces or supplements almost conventional washing processes by working without water – a decisive advantage in terms of energy savings and sustainability. The central unit for this is the WiPa MD – a dry cleaner that works with friction, impact and intelligent screening technology. The aim is to remove loose and detachable adhesions, dust, label residues and bulk material residues – without using large quantities of water. The process is ideal as a pre-treatment for heavily soiled materials or as a final cleaning process for unmixed fractions that are to be transferred to chemical recycling processes.
Advantages of the WiPa dry cleaning process:
– Effective dry cleaning without water – conserves resources and saves costs
– Lower energy requirement due to elimination of energy-intensive drying steps
– Space-saving system design and easy integration into existing lines
– Separation of water and impurities such as paper, organic substances and sand
Washing
Washing – removal of impurities and residual adhesions
In chemical recycling too, the quality of the input material is a key factor in determining the efficiency of the process. An intensive washing process to remove organic impurities, fillers, labels and other adhesions is therefore essential.
WIPA offers fully integrated washing components for this purpose, including Frictionwashers, separation units, as well as rinsing and float/sink tanks, which can be flexibly integrated into processing plants. The systems have a modular design and can be adapted to individual requirements.
Agglomeration
Agglomeration as a preliminary stage: structured material preparation
Before entering the chemical recycling process, it is crucial that plastic waste is converted into a processable, volume-reduced and homogeneous form. This is where agglomeration comes in: Thermomechanical compaction is used to convert films, foams or thin-walled packaging, for example, into free-flowing agglomerates.
The PC series agglomerators developed by WIPA are characterized by their high energy efficiency, variable process control and robust design. They enable defined pre-treatment that optimally prepares the material for chemical recycling. Thanks to intelligent control technology, the process can be individually adapted to parameters such as material type and moisture.
Process variants and advantages
Depending on the type of plastic waste, there are two common process variants:
1. dry cleaning → agglomeration: For some chemical recycling processes, dry cleaning with the MD may be sufficient. The cleaned and dehumidified material is then compacted in the Plast-Compactor and dried if necessary. This resource-saving process saves water, removes up to 95% of impurities, reduces energy consumption and produces a homogeneous agglomerate.
2. washing/separation → agglomerationFor heavily soiled post-consumer plastics, a wet washing line is used after dry cleaning. The pre-wash screw, separation tank and Frictionwasher remove organic residues and impurities; the residual moisture is evaporated in the Plast Compactor. The result is a clean, dry and compacted agglomerate.
WIPA’s modular systems allow both variants to be combined or adapted. The close integration of mechanical pre-treatment, washing and agglomeration ensures that the material streams for chemical recycling are homogeneous, dry and free of impurities. Studies show that a high degree of sorting and cleaning increases the efficiency of the subsequent thermochemical processes and conserves resources.
Conclusion: Sustainable and economical processing is the key to advanced recycling
In chemical recycling, the quality of the input material determines the yield, purity and cost-effectiveness. With the processing solutions from WiPa Werkzeug- und Maschinenbau GmbH, plastics can be prepared in a resource-saving, efficient and process-oriented manner – from agglomeration to washing and dry cleaning. WiPa thus makes an important contribution to the successful implementation of chemical recycling in the circular economy of tomorrow.
