Butyl Rubber Sigma Mixer

Butyl rubber is extremely tacky, exhibits non-Newtonian flow behavior, and has very high viscosity (often 1–10 million centipoise). The sigma blade mixer overcomes these challenges with intense shearing, folding, and kneading forces that ensure uniform mixing and dispersion of compounds.

The mixer is offered in Stainless Steel 316, Stainless Steel 304, or Mild Steel. Stainless-steel versions can be finished in matt or mirror polish; mild-steel units receive one coat of red oxide primer plus two coats of epoxy paint.

Models range from ASM-50 (approx. 50 L working / 80 L gross) to ASM-3000 (approx. 3000 L working / 3800 L gross). Motor power is available in general and heavy-duty ratings, with voltage adjustable to local requirements.

Two Z-shaped (sigma) blades rotate toward each other at different speeds (typically a 3:2 ratio in tangential design), transferring material from one end of the trough to the other. The action combines bulk movement, stretching, folding, dividing, and recombining, plus shearing against the blades and walls for effective size reduction and homogenization of sticky materials.

Key features include tungsten carbide or Stellite blade edges and trough wear plates (to resist abrasion from fillers such as carbon black), an extrusion discharge screw that produces sheets or strips directly for a two-roll mill, and a vacuum system with liquid-ring pump plus dust filter to prevent material loss.

Yes. A jacket for heating or cooling with mineral-wool insulation is available. A temperature control unit (TCU) supports switching between steam/hot oil and chilled water, which is important for managing process temperatures and scorch safety in rubber compounding.

Discharge can be manual (hand-wheel operated) or hydraulic (automatic). An extrusion discharge screw (bottom valve) is particularly useful, delivering the product as a sheet or strip ready for further processing on a two-roll mill.

Options include a liquid spray system, vacuum system, blade-cooling arrangement, screw system, automatic valve discharge, PLC with recipe management for reproducible batches, and explosion-proof design when solvents or zinc oxide dusting is involved.

It is widely used in the rubber industry for manufacturing sealants, adhesives, chewing gum bases, waterproofing membranes, automotive components, and other high-performance butyl rubber products that require thorough mixing of high-viscosity, sticky compounds.