The design precautions for the plastic extruder barrel are as follows:
1. The barrel should be straight.
2. The barrel should be designed to withstand the working pressure of the extruder. These pressures can be as high as 70-140 MPa (10,000-20,000 psi) and are even higher in injection molding.
3. The inner wall surface of the barrel should be more wear-resistant than the extruder screw, because the screw is easier to replace than the barrel, and the rework is also cheaper than the barrel.
4. The support at the rear end of the barrel should be supported by a sliding support that allows the barrel to expand as it is heated. Rigid support can cause the barrel to bend, which can cause serious damage to the screw and barrel.
5. In order to improve the group transport, the feeding section of the barrel can be slotted. The grooving section should ensure good cooling capacity to remove the heat generated by high friction and prevent the melting of the accumulated material in the tank. In addition, the grooves should be inclined and the depth gradually becomes shallow, minimizing the chance of material hanging in the structure.
6. If there is no air vent, it should be biased and the side walls of the opening tangential to the inner wall of the barrel to reduce the chance of the plastic melt hanging on the front edge of the vent. Compared with the traditional symmetrical exhaust port design, the material is easily blocked at the bottom of the exhaust port. The opening of the vent can be designed to be inclined downward to avoid cooling the extruder extruder barrel.
