The Lab

Molding tools that actually run

Free calculators for the studies that set up a molding process, in the order they are run — each one fixes a setpoint the next one holds constant. Enter your own numbers; nothing is stored unless you choose to contribute a study.

Three calculations changed in September 2026

Lab studies recompute from your data every time a link is opened, rather than storing an answer — so a study you shared earlier now shows the corrected result. Three methods changed:

  • Gate seal is now the first of three consecutive weights within 0.1% of each other, which is the criterion the study procedure on that page always described. It was previously the first single step under 0.5%, which tended to report seal earlier than it happens.
  • Viscosity curve takes the optimal velocity from the middle of the shear-thinning plateau rather than the flattest single step, which could land on the edge of the range tested.
  • Process capability reports Cpk from within-subgroup sigma and Ppk from overall sigma, labelled separately. The single figure shown before was the overall one, which is Ppk — the number a customer’s SPC package computes.