Differences in wall thickness cause changes in the speed of the melt front.
This can lead to air traps, weld lines, e.g..
To get a well balanced, homogeneous flow behavior, decreasing local wall thickness, called flow deflector, can slow down the flow front in a specific area.

Flow Deflector in Plastic Industry

Quality: The melt advances in the thick area leading to an air trap.

Flow Deflector in Plastic Industry

By adding a flow deflector the thick wall is reduced and the air trap gone.

Related topics:

This glossary of plastic industry is provided by PLEXPERT Canada Inc.