Sigma Mixer / Sigma Mixer Extruder Introduction
The PerMix PSG series Sigma Mixer / Sigma Mixer Extruders, which is also known as the Double Sigma Mixer, or Double Z Blade Mixer, is used for the mixing-kneading of materials with very high viscosity (over 500,000 cps).
With its unique design of Z-shaped mixing tools installed in two semi-cylinders, the PerMix PSG series Sigma Mixer / Sigma Mixer Extruder is able to provide a combined functions of compressing, stretching, folding, kneading & mixing, which makes it widely used in the chemical, food, sealing compound and paint industries, among others. If a screw extruder is applied for discharging, the mixer is also called Sigma Mixer Extruder, or Mixtruder.
In the PerMix PSG series Sigma Mixer / Sigma Mixer Extruder, there are two special designed Z-shaped rotating elements installed in a W-shaped chamber, the intersection of which forms a saddle piece and meeting tangentially just above the saddle. They rotate at different speeds (usually in the ratio of 3:2) and in opposite direction. The Sigma Mixer Extruder has a screw fed extruder mounted on the bottom of the trough, that extrudes the product and discharges the product through and end plate that is also equipped with a dye plate and knife set. The dye plate and knife set can be customized to allow for forming of shapes, deposited in custom lengths. These dye plates and knife sets can be changed quickly to allow for various shapes and sizes to be extruded. Perfect for bakeries, pet food manufacturers, or food manufacturers.
There are mainly three ways for discharging the product after mixing:
- Tilting TankFor small machines (PSG-1 to PSG-15), tilting can be done manually with a mechanical type (handlever or hand wheel). For greater machines, electro-mechanically or hydraulically powered tilting system is supplied. PerMix supplies the feature that at tilted position, the blade will rotate at low speed (usually 20% of full speed) in reverse direction to aid the discharge by pushing two buttons with both hands.
- Extrusion Screw The extrusion-discharge screw is located in the saddle section and runs in a cylindrical trough tangential to, and below the 2 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 in the side of the machine. The extrusion screw has its own separate drive so that blades and screw operate independently.
- Bottom DischargeThe Sigma Mixers, since also used in pastes, reductions, and concentrates, can also be equipped with a bottom type discharge valve, which allows for discharge via two valves, located on each side of mixing trough.

- All specifications are as accurate as is reasonably possible, but they are not binding.
- Arms speed can be specified by the customer.
- Customized sizes are available against request.
- PerMix reserves the right to modify the design without notice.
- Quick disassembly & Easy cleaning design
- Lab-size for R&D applications (Full volume of 1, 3, 5, 15L)
- Overlapping arms
- Special ‘Duplex’ kneading arms for intensive kneading
- Variable speed drive
- Hydraulic power pack for tilt-able trough
- Vacuum execution
- Welded jacket to the trough for heating & cooling
- Bored shaft / arms for heating & cooling
- Special ‘Duplex’ Kneading Arms
- Explosion proof, Ex certified motors / vessels
- Custom dye plates & knife sets