skrapprover

Skrapprover is a device used in materials testing to assess the adhesion of coatings and thin films by controlled scraping or scratching. The term combines the Danish words for scrape (skrape) and test (prover), and the concept is employed in laboratories and quality control settings to evaluate how well a coating remains bound to its substrate under mechanical stress.

In typical use, a stylus or blade is pressed against the coated surface at a chosen angle and with a defined loading regime. The load is increased in small steps or linearly while the instrument records thrust, displacement, and sometimes time. The test continues until visible coating damage or delamination occurs. The point of failure, the mode of failure (adhesive, cohesive, or substrate damage), and the corresponding load or distance are reported as the main results. Some implementations also provide raw force–displacement curves for more detailed interpretation.

Skrapprovers come in manual and automated variants, with features such as interchangeable tips, different blade geometries, and data logging. They are used across industries including paints and coatings, wood finishing, plastics, automotive, and electronics, where assessing coating durability is important for product performance and quality control.

Limitations include sensitivity to blade geometry, coating thickness, surface roughness, and substrate properties, which can affect reproducibility. Results are typically considered indicative of relative adhesion performance rather than universal material properties, and standardized testing conditions are recommended when comparing data. See also scratch tests and other adhesion assessment methods.