... : >2.0mm Bimetallic Layer Hadness: HRC55°-72° Material: Cold feed rubber screw and barrel: Specification: Ф40-Ф300MM L/D Ratio: 8 ... and barrel: Specification: Ф30-Ф250MM L/D ratio: 4-8 Pin-rubber screw and barrel: Specification: Ф60-Ф250MM L/D ratio: 12 ... , such as gradual, mutant, wavy, double-screen, distributary, separating, exhausting, pin type, mixed, double screws, three screws.