Rubber machine screw barrel, the series products are made of metal materials such as: 38CrMoALA (JISSACM645), CW6Mo5Cr4V2, 9Cr18MoV and other metal materials, also through heat treatment, using nitriding treatment, plating hard chrome layer , high-frequency quenching, spraying corrosion-resistant, wear-resistant bimetal layer, vacuum quenching and other methods of treatment.
The screw barrel is subjected to high temperature and high pressure during the manufacture of the product. At the same time, it is subject to mechanical scraping (especially when producing glass fiber filled materials). Some plastics also have chemical corrosion effects. The operating temperature of the barrel sometimes reaches a high temperature of 400 ° C and a pressure of 29.4 - 49 MPa, and even a pressure of up to 68.65 - 78.45 MPa. The barrel works under these conditions and requires mechanical properties to be sufficient.
More: Screw Manufacturing Rubber Extruder Screw The inner surface of the barrel is scratched. Constantly increase the gap between the machine and the barrel is working. Some corrosive plastics, such as vinylidene chloride, have a large corrosive effect on the barrel during processing. Processing plastics containing fillers, resulting in more serious wear and tear. Especially when processing Boli fiber reinforced polyamide 66 (nylon 66), the wear is severe.
Material and strength of the barrel
When the material is selected, it is important to determine the safety factor of the extruder when it is designed and calculated. It is also important to ensure that the extruder works safely and permanently.
In general, the strength calculation or strength check is performed on the connection bolts of the barrel, the head and the barrel, the connecting bolt between the barrel and the reduction box, the reduction box, and the safety pin for preventing overload. One exists
3 Normally, the safety factor of the rod is set to be large, and the order of the second is the connecting bolt of the barrel, the barrel and the reduction box, the connecting bolt of the machine head and the barrel, and the safety factor of the safety pin (overload protection pin) is set. Set to the minimum. When the safety factor is specifically selected, the safety factor of the barrel is often set between 2.5 and 3.