Screw Extrusion Kneader

A sticky compound can mix well and still refuse to leave the vessel. If the bottom pocket is left alone, powder and dough stay behind; if discharge is manual, the line loses time around a hot batch. Here the same screw circulates during mixing and transfers the finished compound after the outlet is opened.

Independent WEG drives keep the Z-blade job separate from the extrusion job. The bottom screw has its own Siemens speed command, so the transfer rate does not have to follow the main kneading speed.

Screw geometry, outlet, reducer and bearing support are specified together. Schneider and Chint electrical components provide the control and protection layer for mixing, reverse circulation and final extrusion.

The commercial question is what reaches the receiving line and how much time is spent getting it there. The parts below show where the extra drive and control points help, while the Z blades remain responsible for primary kneading.

WEG Motor

Guomao Gear Reducer

Siemens Inverter

NSK Bearing

Schneider Electrical Components

WEG Motor

One WEG motor is reserved for the main Z blades, where cold rubber and dense dough create the highest mixing load. A separate motor can be assigned to the bottom screw, keeping the two duties from competing for the same power.

Guomao Gear Reducer

Guomao reducers are matched to the main and screw torque paths. Ratio, service factor and outlet speed are checked with the receiving line's throughput, not simply copied from one duty to another.

Siemens Inverter

A Siemens inverter gives the extrusion screw its own speed command. Reverse movement during mixing avoids a dead pocket; forward movement during discharge can be set to the customer's downstream equipment.

NSK Bearing

NSK bearing support keeps both shaft lines aligned under high torque and the axial load created by extrusion. Stable geometry protects seals and helps the screw run without rubbing the housing.

Schneider Electrical Components

Schneider components provide the interlock and protection platform for two drives, screw direction change and the discharge sequence. The panel is arranged around the customer's line controls and safety practice.

 

Applications

 

The screw option is considered when a thick batch must leave through a controlled route instead of being scraped or tipped. The NH/NHZ-20 reference entry is 20 L total capacity, 14 L working capacity and a 4 kW motor at 48/36 rpm; larger sizes are checked against the receiving rate.

 

Rubber & Plastics

Butyl rubber, silicone and filled plastic doughs often need positive conveying after kneading. The bottom screw gives the operator a clear route from a fully worked batch to the next process.

Chemical & Adhesive Materials

Hot-melt adhesives and non-flowing chemical pastes are difficult to pour when the next step expects a steady feed. Screw speed and outlet geometry can be matched to a pump, packer or extruder.

Carbon & New Materials

Conductive pastes and binder-rich materials can remain in a bottom pocket if the screw is idle. Reverse circulation keeps them available for mixing, and forward extrusion supports cleaner recovery.

Food Materials

A screw discharge may be useful for dense food or confectionery dough when a fixed, metered transfer is preferred. Sanitary screw surfaces and cleaning access are confirmed for the intended recipe.

The production layout combines a W-shaped mixing chamber, bottom extrusion screw, two drive paths and a defined outlet. From the outside, the route from high-viscosity kneading to downstream transfer is easy to follow.

Active bottom extrusion layout

Screw diameter, pitch, reverse speed, outlet connection, seal and receiving rate are confirmed before fabrication. These checks tie the extra hardware to a material-recovery target the customer can review.

PDI for the screw extrusion kneader can include independent motor runs, screw direction and speed checks, bearing temperature, outlet inspection, weld review and sequence interlocks. The final documentation matches the delivered two-drive configuration.

CE / EMC certificate example

Technical file example

The two drive paths and outlet are protected during packing, the base is fixed to a steel skid and the machine is crated in reinforced timber. We provide loading photographs, a 12-month warranty and remote guidance for screw direction and commissioning checks.