I received a follow-up question regarding a post earlier this year, The Uses of MFI…,
You mentioned the spiral flow, what is this test?
The spiral flow test uses a mold with a long spiral flow channel emanating from the center. Notches are etched along the flow path to help identify the length the polymer has flowed within the mold. The mold can be filled using either a constant velocity (constant shear) or constant pressure (constant strain) to determine the polymer behavior.
The behavior of the polymer can be evaluated based on process output data such as flow length, part weight, and pressure at transfer. When using the spiral flow test, it is best to use a mold which has a channel thickness similar to the parts actually being molded.
You might want to consider purchasing a small, inexpensive, molding machine to conduct spiral flow tests on every incoming batch of material.