Surface testing

GWP mbh carries out the following surface tests on various materials:

  • tests for colour fastness in the form of dry abrasion and wet abrasion with different media
  • testing for abrasion resistance
  • scratch resistance test
  • pencil hardness testing

Abrasion resistance - Color fastness test

The abrasion resistance is the resistance of a solid surface to mechanical stress caused by friction, whereby the color fastness is determined by dry friction and wet friction of the component.
After the test, the component is examined for color changes in the friction track.  The friction material is assessed for bleeding or paint abrasion with a grey scale.

Standards: DIN EN ISO 105-X12, PV_3906_DE, TL 226, SES N 3243

Abrasion resistance - Micro-scratch resistance

The abrasion resistance of a component is the relative change in gloss as a percentage of the initial gloss level. A gloss measurement is carried out on the component in its unchanged state.
Subsequently, a micro-grain attached to a Type C friction pin is rubbed on the component.
Then the gloss in the scrubbed area is measured and the abrasion resistance is determined.

Standards: TL226, PV 3987, DIN EN ISO 12947-1

Scratch resistance

A scratch hardness tester can be used to test the scratch resistance of a coated surface. A scribe stylus is pulled over a test piece with a previously defined constant force.
With a "Yes/No test" it is finally tested whether the scribe penetrates the surface up to the substrate with this force or not.

A test at a minimum load that penetrates a surface to the substrate is performed by increasing the scoring force.

Standards: AS/NZS 1580.403.1, PV 3952, TL 226, BS 3900-E2, DIN 53799, ECCA T12, EN 13523-12, ISO 1518-1

Pencil hardness test

Also scratch hardness test according to Wolff-Wilborn. Fast and uncomplicated test for testing surfaces.

A pencil is drawn over a coated surface at an angle of 45°.  The pencil is pressed onto the component with a certain force. A distinction is made between the hardness of the pencil, which leaves only a writing trace on the test piece, and the hardness of the pencil, which leaves a scratch on the component.

ASTM D 3363 also speaks of groove hardness and scratch hardness.

Standards: ASTM D 3363, BS 3900-E19, ISO 15184, JIS K 5600-5-4, SES N3243