According to a certain arrangement of pin set, to varying degrees of density, the number of months. Cylindrical pin is the pin which is assembly to the Screw Barrel hole formed; square or diamond-shaped pin in the Screw Barrel is directly formed on the milling. If these pins are set in the melting zone, the solid bed can be broken pins, damaged two-phase flow, the solid and liquid mix together to make the end pieces and dissolved solid materials has been the contact area to increase capacity and promote melting.

If the pin is set in the melt conveying zone, their main role is to split the material flow, increasing the interface, changing the direction of material flow, the beam re-arranged. Multiple streaming, convergence, change the flow direction, so that all of the melt composition and temperature. Mixing section are set in the general homogenization of the end of the Screw Barrel slot inward structure, its diameter and Screw Barrel diameter equal.

Groove is divided into several groups, each group of materials between the confluence area. Trench material is divided into the convergence zone will sink, and then split, convergence, and its principle is similar to the pin type.