Pneumatic Conveying Elbows
for Plastic Pellets

Pellet Conveying and Product Quality

Plastic granules are often conveyed through multiple bends between production, storage, blending and packaging operations. Each turn changes particle trajectories and can contribute to frictional heating, smearing or fines. Problems may be intermittent and depend on grade, pellet shape, velocity or temperature.

Streamers, Smearing and Fines

Streamers and Angel Hair

Thin strands or flakes can form when pellets rub or smear against surfaces under unfavorable conditions. The phenomenon may be influenced by resin formulation, pellet temperature, wall condition and conveying velocity, not just the elbow’s nominal radius.

Particle Degradation

Repeated impacts can crack or chip pellets and increase fines. Compare particle quality before and after conveying, and note if the issue begins at a particular branch or change in velocity.

Pocket Versus Sweep Considerations

A pocket elbow may reduce direct metal-wall contact in a suitable application, but a material pocket can also hold a different resin or color after line shutdown. A sweep provides a continuous passage but can create extended wall contact. There is no universal winner without material- and process-specific measurements.

Temperature and Velocity

Actual conveying gas temperature, pellet temperature and the line’s operating velocity influence surface interaction. Avoid designing only for a nominal air-flow value stated at unspecified pressure or temperature. Where the resin is temperature-sensitive, define acceptable product temperature changes and fines generation.

Cleaning and Changeover

Frequent recipe or color changes place additional value on cleanability and low retained product. Review pocket geometry, internal joints, valves and downstream branches as part of the entire route. Ask how the required clean condition will be measured.

Request an Application Review

Send polymer type and grade, pellet size, conveying rate, gas velocity or flow, temperature, existing elbow geometry, sample photos of streamers and expected changeover frequency. Compare product families · Request a technical review.