Table 2.

Different downsizing methods used in recycling rubber waste [59]

Methods	Description	Characteristics of the ground rubber particles
Dry ambient	Repeated grinding of rubber waste until crumb rubber is obtained	Size approximately 300 µm rough and irregular surface
Wet ambient	Grind suspension of shredded rubber in the presence of water as coolant	Size approximately 100 µm rough and irregular surface
Water jet	Uses pressurized water jet (> 2000 bar) to strip and breaks rubber	Rough and irregular surface
Berstoff’s method	Uses the combination of rolling mill and twin-screw extruder	Rough and irregular surface
Cryogenic	Rubber cooled in liquid nitrogen and shattered using impact type mill	Size approximately 75 µm sharp edge, flat/ smooth surface