pinchtest

Pinchtest is a mechanical testing method used to evaluate the resistance of a material or assembly to pinching forces. The test uses a pin-shaped indenter advanced toward the specimen under controlled conditions, with load and displacement recorded to determine penetration or failure.

Test setup typically includes a fixed stage to hold the sample, a defined travel range, and an indenter with specified geometry (diameter and tip radius). The specimen is secured, the indenter is driven at a defined rate, and data such as peak load, displacement at first failure, and energy are captured.

Variants include static pinchtest, where load increases at a constant rate until failure; dynamic pinchtest, which uses rapid loading or impact; and multi-indenter configurations for edge or corner effects.

Applications span coatings and films, textiles, protective layers for electronics, packaging materials, and some medical devices, where puncture resistance or pinch durability is important.

Interpretation depends on geometry and loading rate, so standardization is important. Results should be compared from matched specimens using identical indenter configurations, and limitations include sensitivity to thickness, surface roughness, edge effects, and misalignment.

History and status: Pinchtest emerged in the early 21st century in materials research and quality assurance as a compact method for assessing puncture resistance. It lacks a universally accepted standard, and practitioners often document method parameters with results.

See also: indentation test, puncture test, peel test.