Large-scale and precision realization of large-scale ex […]
Large-scale and precision realization of large-scale extrusion molding equipment can reduce production costs, which is more obvious in large-scale twin-screw granulating units, blown film units, and pipe extrusion units. The major technical equipment required for national key construction services, and the large-scale extrusion granulation unit of one of the three key equipments for large-scale ethylene projects have long relied on imports. Therefore, it is necessary to speed up the localization process to meet the development needs of the petrochemical industry. The precision can increase the gold content of the product. For example, multi-layer co-extruded composite film needs precision extrusion, and as an important means to achieve precision extrusion, the melt gear pump must be intensively developed.
High-speed, high-yield extruders are high-speed, high-yield, allowing investors to achieve higher output and high returns with lower investment. However, the high speed of the extruder screw speed also brings a series of difficulties that need to be overcome: if the residence time of the material in the screw is reduced, the material will be mixed and plasticized unevenly, and the material may be subjected to excessive shearing, which may cause sudden heating and heat of the material. Decomposition, difficult to control the extrusion stability will cause the geometry of the extrudate to fluctuate, the accuracy of the related auxiliary devices and control systems must be improved, and the wear of the screw and the barrel is intensified. High wear-resistance and ultra-high wear-resistant materials are required. Problems such as how to improve the life of the bearing at high speeds need to be solved.
Intelligent and networked extruders in the developed world have adopted modern electronic and computer control technology, process parameters for the entire extrusion process such as melt pressure and temperature, body temperature, main screw and feed screw speed, The feeding amount, the ratio of various raw materials, the current and voltage of the motor, etc. are detected online, and the closed-loop control of the microcomputer is adopted. Some companies have adopted online remote monitoring, diagnosis and control to network control the extrusion molding line. This is extremely advantageous for ensuring the stability of the process conditions and improving the accuracy of the product.
In terms of function, the Extruder Screw is no longer limited to the molding and mixing of polymer materials, and its use has expanded to include food, feed, explosives, building materials, packaging, pulp and ceramics. In addition, the "one-step direct extrusion process" which combines the kneading granulation and the extrusion molding process into one is also very attractive.