- The test method specifies suitable cutting tools with either single or multiple cutting
edges. The cross hatch cutter in the form presented in the photograph, with either 1, 1.5, 2 or 3mm spaces between the cutting edges, has advantages over the single cutting blade for both safety and simplicity in use.
- The instrument consists of a base plate, panel holder with clamp, a series of mandrels and the handle/bending mechanism. The base should be secured to a suitable work surface, allowing the operator to turn the handle smoothly during a test. The diameter of the mandrel to be used depends upon the test specifications
- The test consists of placing a small volume of product on the deep end and drawing it with a straight scraper toward the shallow end. The position on the scale where oversize particles and their tracks appear can be rated for determination of dispersion.
- The pencil test uses constant pressure and variable hardness of the test tool as its fundamental principal. Pencils of varying hardness, starting with the hardest lead, are moved over the surface under a fixed pressure of 7.5 Newtons (765 gms) and at a fixed angle of 45 degrees to the surface. The degree of hardness of the pencil which damages the surface is taken as a measurement for scratch hardness.
- To determine the impact resistance, surface damage and penetration by a falling weight.
- Most protective coatings and constructional materials must be tested;
- Paints Plating Plastics
- Varnishes Plastic coatings Resins/composites
- Coil coatings Laminations Sheet materials and metals