Meaning
Mechanical surface metrology measures topological variations by physically dragging a diamond tipped probe across a substrate. Contact stylus profilometry detects variations in height through the vertical displacement of this needle as it traverses a path across the measured area. The instrumentation captures data by converting physical movement into electrical signals.
This output quantifies roughness, waviness, and step heights of a material surface.
Moulding Control
Cavity wall finish directly dictates the texture transferred to the polymer part during high pressure injection. Operators perform contact stylus profilometry on finished inserts to confirm that the tool achieves required Ra values before production begins. High readings on the steel surface correlate to increased friction and part ejection difficulty.
Excessive roughness prevents consistent demoulding and raises cycle times through forced cooling delays.
Resin Specification
Virgin pellets contain additives that dictate melt flow and shrinkage performance within a specific thermal window. Deviations from expected material density result in sink marks or warped features when the cooling rate remains constant. Contact stylus profilometry tracks the depth of these surface defects to evaluate whether the batch meets the tolerance set by the print.
Regrind usage shifts the viscosity, meaning the resulting part texture might differ from the baseline measurement even when the process settings remain identical.
Metrology Calibration
Reference standards consist of calibrated glass or metal blocks with known heights to verify probe performance before an assessment occurs. Calibration cycles account for tip wear since the diamond radius blunts over time through repeated friction against hard surfaces. Stylus force settings require adjustment to prevent damage to softer polymer substrates or delicate coatings.
Proper monitoring ensures that data variations originate from the component topography instead of mechanical fatigue of the sensor.
