Study on Slow Crack Growth Resistance of High-Density Polyethylene Pipes Prepared by Vibration Extrusion

The slow crack growth resistance is one of the key factors to improve the service life of the plastic pipes. The high-density polyethylene (HDPE) pipes were prepared using a self-made electromagnetic dynamic plasticating extruder, which applied a vibration force field to the entire plasticating and extrusion process by the axial vibration of the screw. The slow crack growth resistance of HDPE pipes prepared by static extrusion and vibration extrusion was investigated. The effects of the vibration force field on the slow crack growth resistance of HDPE pipes were studied by DSC and WAXD analysis. The results showed that HDPE pipes prepared by vibration extrusion had higher melting temperature, higher crystallinity, larger crystal sizes, thicker lamellas and more perfect crystals. At the same time, the quasi net structure of the HDPE pipes chains can be obtained. All these are favorable for the improvement of the slow crack growth resistance property HDPE pipes.