ISO 28199-1:2021 Paints and varnishes — Evaluation of properties of coating systems related to the spray application process — Part 1: Vocabulary and preparation of test panels.
closed or already burst blister in a layer, arising when solvents or cleavage products evaporate from chemical crosslinking
Note I to entry: If hubbies are caused by the process control, the formulation components or both, the viscosity of the paint film has increased too rapidly during the drying phase so that solvents or reaction products still in the paint film have built up at the polymer paint skin which forms, usually resulting in closed blisters and sometimes resulting in burst blisters. Discontinuities can he identified in more detail using a cross-section.
non-variability, or variability within agreed tolerances, of colour despite variation of influencing factors
Note 1 to entry: Examples of inhluenL-ing factors are thickness and application method.
distance between individual measurements on the test panel in the dx and dy directions
non-uniform appearance of a film caused by the presence of irregularly shaped, randomly distributed areas on the surface that vary in colour and/or gloss
[SOURCE: ISO 4618:2014, 2.1601
ability of a coating material already applied to absorb overspray particles of the same coating material resulting from a subsequent application
Note 1 to entry: Evidence of poor overspray absorption is shown, for example, by raised surface texture (ilZ) and low colour stability (12) as well as mottling (14).
presence of small holes in a film or coating resembling those made by a pin
Note 1 to entry: Pinholes can he caused by gas inclusions in the base coat that reveal a discontinuity after the application of the clear coating material. They are often the result of inappropriate process parameters. Pinholes are similar to craters and bubbles (11). Discontinuities can be identified in more detail using a cross-section.
[SOURCE: 150 4618:2014, 2.195, modified — Note 1 to entry added.]
process hiding power
minimum thickness above which the complete coating system in combination with the colour of the complete substrate achieves colour stability (12) or the colour location achieves a value agreed by the interested parties
Note 1 to entry: See also “hiding power”, defined in ISO 4618:2014, 2.138, as “ability of a coating material or a coating to obliterate the colour or the differences in colour of a substrate”.ISO 28199-1 pdf download.