The development of a new extruder was necessitated for blow moulding of L-ring drums. L-ring drums are made of HMWHDPE having very low melt index, about 2 HLMI.
With smooth bore extruders the extrusion of HMWHDPE poses many severe problems such as uneconomical throughput, surging, excessive temperature fluctuation and attendant viscosity variations of extrudate leading to poor control of product quality and unsustainable production.
Our extruder with grooved barrel and pressure relieving system eliminates the above problems. Besides pressure relieving system, the extruder screw features good dispersive and distributive homogenisation system including multiple splitting and reorientation. An extrudate with low temperatures and adequate homogenisation is obtained.
Also the extrusion screws are tungsten carbide coated. The coating is full encapsulation throughout. The benefit is a lot longer service life with little loss of throughput.