The Lab · Process

Cosmetic Window

Sweep two parameters against each other and judge each combination pass or fail. The tool bounds the region that passes and finds its centre — because a setpoint on the edge of the window makes good parts only until the first thing drifts.

Trials
Material
Melt °C
Mold °C
Horizontal axis
Vertical axis

Judge at least two trials to map a window.

  • One row is one trial: two setpoints, then a pass or fail on the part.
  • A window needs failures on both sides — passes alone leave it open-ended.
  • Judge every trial; an unjudged one is set aside, not counted as a fail.

How to run this study

Map which combinations of two process parameters produce a cosmetically acceptable part, and how much room surrounds the centre. A process set on the edge of its window makes good parts until the first thing drifts.

Procedure

  1. 01Choose the two parameters to sweep. Hold pressure against melt temperature is the usual pair.
  2. 02Pick three to five levels on each axis, spanning wider than you expect the window to be.
  3. 03At each combination, mold five shots to stabilise, then judge the last part against the acceptance criteria.
  4. 04Record pass or fail for every combination, and for a failure, which defect appeared.
  5. 05Enter the grid — the tool bounds the passing region, finds its centre, and reports how wide it is.
  6. 06If a passing point sits at the edge of what you swept, extend that axis and repeat: the window was never closed on that side.