A new recycling technology: Compression molding of pulverized rubber waste in the absence of virgin rubber

Recycling of rubber waste poses a challenging environmental, economical, and social problem. In the present study, we propose a new two-stage recycling process to reuse a rubber waste. First, the granulates of the waste were pulverized into small particles using a single screw extruder in the Solid State Shear Extrusion (SSSE) process. Then, the produced powder was compression molded in the absence of virgin rubber. The slabs prepared at various molding conditions were subjected to mechanical, chemical, and microscopic tests. It is found that the slabs have high extensibility with low-medium tensile strength. Compressive creep of the powder, self-adhesion of rubber molecules, and interchange reactions of polysulfidic crosslinks are proposed as the basis of particle bonding.