Screw Inspection

Modified on Sunday, 01 February 2015 05:00 PM by mpieler — Categorized as: Extrusion Hints

Screw Inspection[BR} Vol. 17 #3, Dec. 1990

During the inspection of a new or rebuilt screw, take the time to measure the depth of all major channels (melt, solid, etc.) at least every turn. Then, plot the results on graph paper to check the profile between the major index points (end of feed, beginning of metering, etc.).

Check to insure that constant depth channels remain constant and that the transition section varies uniformly. Variation in the taper of the transition section can result in serious disruption of the solid bed, giving rise to instabilities of an otherwise proven design. If you find a nonuniform taper in a transition section, have it polished out.

See also:
Return to Extrusion Hints