In the polymer extrusion industry, the single-screw extruder is the most common continuous extruder, which has the advantages of low cost, simple design, good toughness, high reliability, and high-cost performance. A standard single-screw extruder has three zones of geometric variation:
1. Feeding area
2. Transition zone or compression zone
3. Metering area

The three zones are created by a constant pitch but different screw channel depths. The depth of the screw channel decreases linearly from the feed zone to the metering zone, which leads to a compression phenomenon. For screw geometries with only one compression section, it is often referred to as a single stage. Zone lengths and maximum and minimum channel depths may vary for the same screw length and diameter. Therefore, different screw profiles are possible.

The thermochemical environment inside the extruder can also vary due to:
1. Screw profile
2. Set the temperature
3. Screw speed
These factors affect local heat transfer, heat dissipation, velocity distribution, and residence time within the extruder.

Common layouts for single screw extruders include:
1. Heating element. Axial temperature profile for setting the barrel
2. The feed hopper and inlet are located upstream of the extruder
3. Mold. placed on the other end of the extruder