ELASTOMERS AND PLASTICS Closing the Loop by Developing a continuous thermomechano chemical Devulcanization and Activation Process for EPDM Rubber Waste

This paper presents the development of a novel recycling process for EPDM rub ber waste in a twin screw extruder by combining three process steps: chemi cal devulcanization, activation with a li quid polymer (LP), and compounding of the curing system. The effects of LP amount, extruder parameters such as flow rate and screw speed, and amount of curing system were studied. Rheo meter and mechanical tests evaluated the quality of the re-vulcanizates. The secondary raw material was used to produce seals by injection molding, and their properties met the requirements of DIN EN 681-1:2006 for the produc tion of sealing systems. A best practice for the continuous process and compo site formulation is presented. 

The concept of circular economy has led to significant efforts to find suitable in novative processes and strategies for rubber recycling. The challenge of recyc ling rubber in a high-quality and efficient manner lies in the three-dimensional network formed during vulcanization, the variety of rubber compound formu lations, and the complex structure of rubber products that make it difficult to reshape rubber and return it to the life cycle.