The main pin screw part is common screw, pin can be set on a smooth cylindrical surface melting section or the metering section of screw of the low or no end of the metering section of screw groove. The pins are arranged in a certain arrangement, which can vary in density and quantity. The cylindrical pin is formed by assembling the pin into the hole of the screw; the square or diamond pin is formed directly by milling pin on the screw.
If the pin is set in in the fusion zone, the pin can be broken solid bed, destruction of two-phase flow, the solid and liquid phase mixing together, so that the contact area at the end of dissolved solid fragments and has let the material increase, promote melting. If the pin is placed in the melt conveying zone, its main function is to separate the material flow, increase the interface, change the direction of the material flow, and rearrange the flow stream. The flow direction is changed and the composition and temperature are homogenized.
The mixing section is an inward slotting structure which is arranged at the end of the homogenizing section of the common screw, and the outer diameter is equal to the outer diameter of the screw rod. The grooves are divided into several groups, each of which is the confluence area of materials. The material is segmented by the groove, and then converged into the confluence area, and then segmented and converged. The principle is similar to the pin type.
The characteristics of separation type screw is melting section in addition to a screw in the original (called screw), also added a thread (called additional threads), the external diameter is smaller than the diameter of the main thread, the main and auxiliary lead lines, since the end of the feeding section side thread (and associated in with the feeding section), after several threads, the main thread gradually intersect with the homogenizing section.
The screw channel depth and lead from the beginning to the end of the feeding section is gradually changing, which lead from gradually narrowed, channel depth by depth becomes shallower, which can cause the material to get the maximum compression.