Ultra-high molecular weight polyethylene pipe is the most widely used pipe due to its strong performance advantage. There are three main factors affecting the quality of UHMWPE pipe, among which the mold is the most critical factor.
1. Raw materials are the core
At the core of the raw material for the production of ultrahigh molecular weight polyethylene pipes is molecular weight. Theoretically, the higher the molecular weight of the raw materials, the better the wear resistance. However, as a wear-resistant pipe, other mechanical properties should also be considered, considering the stability of its long-term use. Therefore, the raw material with high molecular weight may not be able to produce ultra-high molecular weight polyethylene pipes with good comprehensive performance, which depends on the mold equipment and processing technology.
At present, the processing technology of ultra-high molecular weight polyethylene pipes has not been standardized, and the manufacturers vary greatly. Mainly in the mold structure and process control. Therefore, the surface of the ultra-high molecular polyethylene pipe produced is not different, but the index is very different. The empirical things here also occupy a relatively large proportion. The raw material of the ultrahigh molecular weight polyethylene pipe is an elastomer when extruded, and the fluidity is zero, which is not good for extrusion.
The core structure of the extruder is a screw-opening full traffic trough, a shallow screw thread and a small screw angle. The theoretical core is to increase the screw thrust as much as possible to reduce the bonding of the raw material to the barrel and the screw. The extrusion force is around 400 kg. Polyethylene pipes are due to the high pressure in the extrusion process, so the thin-walled pipes are difficult to squeeze and the molds are easily biased. Therefore the mold is very important.