PLASTICS RECYCLING BY REGRANULATION
Plastic Recycling Using Regranulation
The recycling plant at Křelov contributes to the reuse of raw materials contained in wastes from industrial processes, agriculture, retail networks and households. Recycling is a significant factor helping save natural resources, reduce environmental burden from wastes and improve economy of industrial-scale manufacture. JELÍNEK-TRADING founders and partners could build upon their own experience in scientific research, application of diverse plastics technologies, management of plastics industry plants, as well as upon their expertise in mechanical engineering, accountancy, international trade and foreign languages. The company’s main field of activity is the regranulation of plastic wastes consisting of PP and LDPE as well as other polymers. Other technologies, such as agglomeration, crushing and milling, are also used. A number of other polymer types (HDPE, PA, PS, ABS, PC, etc.) are also processed. The company has been running its own injection moulding facility (HDPE, PP, PA, etc.) since 2002. The company is also active in the trade of original polymers as well as regranulates and crushed material.
Regranulation
The regranulation processes used by JELÍNEK-TRADING can be categorised in 2 basic classes:
- regranulation with washing, applied to LDPE sheets (“wet regranulation”)
- regranulation without washing, applied to clean technological wastes, such as non-woven fabrics, sheets and fibres, largely based on PP, PP/LDPE/PA combinations, and the like (“dry regranulation”).
LDPE sheet wastes are first ground in a knife mill; the ground material is fed to a washer for washing, freed from water in centrifuges, and dried with hot air. The clean and dry crushed material is collected in a silo, from which it is conveyed by a belt conveyor or a pneumatic system into a screw extruder. In the machine the material is transformed into melt, which is filtered at the machine outlet to remove mechanical impurities (paper, wood, etc.) which remained in the material after the washing step. Subsequently the material is granulated on a granulation facility (“granulation in water”). Clean technological waste is processed in the same manner, only the washing and drying steps are omitted. Again, “granulation in water” is the final step of this process. In either case, the final product can be dyed/coloured during the regranulation process as the customer may wish. The final regranulate is transported to a silo, where it is homogenised by mixing and filled into valve bags or big bags for sale. A fraction of the LDPE regranulate is used in-house for the manufacture of waste bags or packaging sheets on the company’s own extrusion blowing line.
