Viscous Rubber Solutions Sigma Mixer

Two counter-rotating sigma-shaped (Z-shaped) blades operate at different speeds (commonly in a 3:2 ratio) inside a U- or W-shaped trough. This creates intensive kneading, shearing, folding, stretching, and recombining actions that disperse fillers, additives, and polymers uniformly—something ordinary mixers cannot achieve.

The mixer is offered in Stainless Steel 316, Stainless Steel 304, and Mild Steel. Stainless steel versions can be finished to matt or mirror polish per customer requirements, while Mild Steel models receive one coat of red oxide followed by two coats of epoxy paint.

Models range from ASM-50 (approx. 50 L working / 80 L gross capacity, 5 HP general or 7.5 HP heavy duty) up to ASM-3000 (approx. 3000 L working / 3800 L gross capacity, 100 HP general or 120 HP heavy duty). Power voltage can be adjusted to suit local requirements.

In the tangential design the blades meet tangentially, with the front blade rotating faster. This delivers strong kneading and shearing ideal for high-viscosity materials such as rubber compounds, adhesives, dyes, and pigments. Overlapping blades are better suited to lighter viscosities.

A jacket for heating or cooling can be fitted, complete with mineral wool insulation and cladding. Optional blade cooling arrangements further help manage temperature-sensitive formulations.

Discharge can be manual (hand-wheel operated) or hydraulic (automatic). Additional methods include bottom valves, an extrusion screw system, and automatic valve discharge—all designed to handle thick materials efficiently while minimizing residue.

A minimum gap between the trough inner shell and the blades reduces the chance of material adhering. PTFE shaft sealing provides food-grade compatibility, and the closed chamber with counter-rotating blades eliminates dead zones for uniform dispersion of fillers, additives, vulcanizers, and plasticizers.

While optimized for rubber compounds, it is also applied in the pharmaceutical, nutraceutical, herbal, Ayurvedic, biotech, cosmetic, and chemical industries for high-viscosity pastes, adhesives, dyes, pigments, carbon pastes, clay coatings, creams, and ointments.

Available options include a liquid spray system, vacuum system (for degassing), screw system for continuous discharge, blades cooling arrangement, and automatic valve discharge. These support controlled temperature, pressure, dust-free operation, and efficient handling of extremely thick materials.