Glycon offers a wide variety of barrier feed screw designs aimed at helping you to process today’s toughest materials. Barrier screws are designed to be more efficient melting mechanisms than single flighted Conventional or General Purpose Screws. Parallel Barriers and Crossing Barriers (ASB/ Variable Pitch) plasticizing screws accomplish this efficiency by imparting more shear into the material and therefore the melting of plastic pellets is accelerated. The Barrier Screw design is different from the single flighted Conventional or General Purpose Screw design in that it introduces a secondary flight, typically at the beginning of the melting or compression zone. The purpose of this flight is to act as a “barrier” between the melted and unmelted plastic.
In a Conventional/General Purpose Screw the melt pool can form an insulating layer around the unmelted plastic, keeping it from melting efficiently. A Barrier Screw doesn’t allow this to happen, because the melt pool and the unmelted pellets are separated into two different channels. Therefore, the melting process is more controlled and efficient.