>> Product | Kneading Mixers | Sigma Mixer

Sigma Mixer:

The Sigma Mixer (other names: double arm mixer, double z-blade mixer, double sigma mixer, sigma blade mixer, kneader mixer) is designed for the mixing-kneading of materials with high viscosity (over 500,000 cps).

The NKM SGK series Sigma Mixer is able to provide combined functions of compressing, stretching, folding, kneading and mixing, and is widely used in but not limited to the chemical, food, sealing compound and paint industries.

The various options available for the NKM SGK series Sigma Mixer enables it to perform particular functions or operate as a general kneader:

  • Tangential arms or Overlapping arms

  • Hydraulic cover lifting and trough tilting

  • Mirror-like polishing for contact parts

  • Heating and cooling jacket trough

  • Cored blades for heating or cooling

  • Vacuum models for de-aerating or drying

  • Variable speed drives for arms and screw

  • PLC control with HMI touch screen

  • Liquid addition unit

  • Ex-proof models

  • Anti-wear treated trough & blades for abrasive mixing

In the NKM SGK series Sigma Mixer, there are two special designed Z-shaped mixing elements installed in a W-shaped chamber. The two mixing elements meet above the saddle piece tangentially or in an overlapping way.

These two mixing tools rotate at different speeds, usually in the ratio of 3:2, and in opposite direction. The mixing action is a combination of bulk movement, smearing, stretching, folding, dividing, and recombining as the material is pulled and squeezed against blades, saddle, and side walls. Continually new layers of material are compressed and folded over one another and are subjected to shearing forces. New surfaces are formed and the components can penetrate into them immediately.

The blades are well ground and polished, successively sweep all points of the trough surface during each revolution, at the same time dividing the batch continuously across the saddle piece and thereby rapidly affecting a perfectly homogeneous mix.

1. Tilting mechanism:
For small models, the chamber can be tilted and discharged, with a mechanism operated manually (handlever or handwheel) or hydraulically.

2. Extrusion screw:
The extrusion screw is located in the saddle section below the two mixing blades. During the mixing cycle the screw moves the material within the reach of the mixing blades, thus assuring a thorough blending of all the ingredients, and at the same time, accelerating the mixing process.

At discharge time, the direction of rotation of the screw is reversed and the mixed material is extruded through suitable die openings at the discharge side of the machine. The extrusion screw has its own separate drive and can be controlled at variable speed.


5L Laboratory Sigma Mixer
500L Sigma Mixer with Jacket
4,000L Ex-proof Sigma Mixer
6,000L Dual-drive Sigma Mixer