The open mill (open rubber mixing / molding machine, commonly known as "two-roll machine") is the core equipment for processing high-molecular materials such as rubber and plastics. Its core principle is to generate strong shear force + roller gap extrusion + temperature control through the speed ratio difference between the two rollers, thereby completing key processes such as plasticizing, mixing, hot molding, and sheet pressing.

1. Raw rubber plasticizing (for rubber-specific use)
 Function: Soften the high elasticity raw rubber (natural / synthetic rubber), reduce the Minitz viscosity, and enhance plasticity to facilitate subsequent processing.
 Principle: Shear force breaks the long molecular chains, resulting in a decrease in elasticity and an increase in fluidity.
 Operation: Thinning and rolling plasticizing, temperature control to prevent scorching.
2. Rubber / plastic mixing (core function)
 Function: Mix the main materials + fillers + additives (carbon black, sulfur, accelerators, plasticizers, stabilizers, pigments, etc.) evenly to form a homogeneous material.
 Effect: Ensure consistent performance of the product (strength, hardness, elasticity, weather resistance, color).
 Operation: Make triangular packages, turn the rubber, and perform multiple thinning processes to ensure uniform dispersion.
3. Heating and plasticizing (preheating / reprocessing)
 Function: Heat the cold rubber / stored rubber to soften and restore plasticity, providing material for calendering, extrusion, and molding.
 Feature: Precise temperature control (±1℃), rapid heating, and uniform preheating.
4. Sheet pressing / molding
 Function: Press the mixed rubber / plastic into uniform thin sheets for storage, transportation, or subsequent molding (calendering, compression molding).
 Precision: Roll distance adjustment ±0.05mm, uniform sheet thickness.
5. Recycling / recovery processing
Waste rubber / plastic are crushed, melted, and recycled to restore plasticity and achieve recycling.