How often do you think about elbows? And no, Tennis Elbow doesn't count. Neither does your funny bone. This edition of Best Practices is about plastics operations, not Operation, the battery-powered board game.
Indeed, this month, Best Practices looks at the type of elbows in pipes for resin conveying systems. As the material zips along, the elbow can be a major wear point — especially when moving abrasive fiber-reinforced pellets. The bend of an elbow marks a sudden change of direction.
And blowouts aren't the only problem. Pellets themselves can get damaged, as material moving at a high speed creates dust, as well as frictional heat that can cause pellets to melt as they skid along the walls of the elbow, forming streamers.
Enter something called the Smart Elbow — and yes, the term is a registered trademark — from HammerTek Corp. of Bethlehem, Pa.
RheTech Inc., which makes polyolefin alloys and compounds, was plagued by blowouts once a month on its conventional stainless steel, long-sweep elbows. RheTech is based in Whitmore Lake, Mich., and also has a plant in Fowlerville, Mich. They run 24 hours a day, five days a week.
The conveying lines transport glass-reinforced pellets from extruders to storage silos and to trucks.