Silver Streaks with PC…

This question arrived this morning via email… TA We are processing polycarbonate and are having problems with short molding as well as silver streaks. The mold design is a hot runner system with three drops. My Response For the silver streaks, I suggest you ensure the material is properly dried. A dewpoint meter or moisture analyzer should […]

Basic Gravimetric Feed Systems…

I was at an extrusion customer site last week and they were not sure whether the feed system was truly gravimetric or volumetric…. Customer The system uses a scale to measure the material used when filling the hopper, but has a feed screw to meter the material to the feedthroat. The system can be set […]

Feed Throat Cooling…

I just received this question via email… MM Most of the plastics raw material data sheet do not contain the Feed Zone temp. How can we  keep this temp during production? My Response Since this cooling is used to prevent bridging most processor runs this temperature at or near the lowest setting. The two common […]

Another Great Use for Compressed Air Dryers…

I was in a discussion with a manager the other day. The discussion turned to material driers and the manager said this… Manager We don’t have any compressed air driers because we process a lot of nylon and we have to dry it centrally as well as at the hopper. My Comments Although compressed air […]