Effect of Barrier Screw Design in Injection Molding Machines on the Plasticization Efficiency of Polypropylene Resin

Abstract

The cooling phase takes the longest time in injection molding process. Subsequently, researchers are focusing on the reduction of cooling time in injection molding process. Appropriate screw design in injection molding machine is required to enhance plasticizing plastics in a short cooling time. In this study, the effects of two barrier screw designs, open and closed barrier flights, on the plasticization efficiency of polypropylene (PP) resin were investigated through melting experiments. Throughput, back pressure, torque, and melt temperature for RPM were measured after screw operation reached a steady state. And the melting behaviors of PP resin were examined by observing the distribution of materials in the screw channels after the screws were removed from the barrel. Plasticizing capability was measured and compared in terms of melting length, the distance between the starting and completion points of melting.

Cavity pressure profile study during foam injection molding and its effect on cell formation of polypropylene/chemical blowing agent foam

“…A constant pressure from the back of the screw (i.e., backpressure) supports the screw when it rotates for plasticization. The screw moves backward and prepares a shot when the pressure of the resin at the tip of the screw is greater than this back pressure 48,49 . Figure 8 represents the respective cavity pressure profiles in relation to various back pressure values ranging from 5 to 15 MPa.…”

Polymer–Metal Interfacial Friction Characteristics under Ultrasonic Plasticizing Conditions: A United-Atom Molecular Dynamics Study

“…It is critical to comprehend and grasp its behavior to apply it successfully. Plastic pellets, for example, can be successfully conveyed in the plasticizing unit of injection/extrusion molding machines by customizing the interfacial friction between the barrel and the screw [ 1 , 2 ]. With its benefits of rapid heat generation, low energy consumption, and high material usage rate, ultrasonic plasticization microinjection molding (UPMIM) technology has recently become an appealing version of thermoplastic microinjection molding [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 ].…”