Technical Specifications
1. Materials of Construction (MOC)
- Base Material - Alloy Steel: High tensile strength and wear resistance. Common Grades: AISI 4140, 42CrMo.
- Stainless Steel: For corrosion resistance, particularly in silicone or specialty rubbers. Common Grades: SS 304, SS 316.
- Surface Hardening:
- Hard Chromium Plating: Increases wear resistance and prevents sticking.
- Nitriding Treatment: Enhances surface hardness to around 60-70 HRC.
2. Rotor Types
Tangential Rotors
Rotors rotate tangentially without meshing. Generates lower shear; ideal for heat-sensitive or soft compounds.
Examples: Standard tangential, Variable helix tangential.
Intermeshing Rotors
Rotors interlock, creating high shear. Suitable for high-viscosity materials and tough fillers.
Examples: Spiral intermessing, Helical intermessing.
3. Design Features
- Helix Angle: Typically between 30�-60�, influences the mixing efficiency.
- Rotor Speed: Fixed or variable, with typical ranges from 20-50 RPM. Differential speed ratio (e.g., 1:1.1 or 1:1.2) ensures efficient shearing.
- Number of Wings: Usually 2 and 3 wings per rotor for controlled mixing. Three Blade Rotor shown in image.
4. Cooling/Heating Channels
- Internal Channels: Allow circulation of water, steam, or oil to control rotor temperature.
- Temperature Range: Typically handles temperatures between 20°C to 200°C.
5. Rotor Dimensions
- Diameter and Length: Varies with the kneader capacity, e.g.:
- 55 liters: Rotor diameter ~250-300 mm
- 110 liters: Rotor diameter ~400-450 mm
- Clearance Between Rotors and Chamber: Typically 0.2 to 1.0 mm for optimal mixing.
6. Surface Finish
Polished to a mirror finish (Ra < 0.4 �m) to prevent sticking and improve cleaning.
7. Applications for Rotor Types
Tangential Rotors
Used for natural rubber, elastomers, or compounds with minimal fillers.
Intermeshing Rotors
Used for high-carbon black compounds, silica-rich mixes, or heavy-duty industrial rubber.