Full definition
Rubber layer on the pulley-side face of the belt that contacts return idlers, pulleys, and slider beds. Standard thickness per DIN 22102: 1.5-3 mm. Must have low abrasion (Type Y: 150 mm³, ISO 4649) and low coefficient of friction to reduce heat buildup. In underground mining belts, must also meet antistatic requirements (max. resistivity 3×10⁸ Ω, ISO 284) to prevent ignition of explosive atmospheres.