Influence of inclination angle and direction on film stability

When carrying out the weather resistance test of the coating film, it is of decisive significance to put the paint sample plate and the ground at a certain angle and face a certain direction.

In order to enhance the effect of sunlight, as a rule, the model should be at an angle of 45° to the horizon. This type of test can be considered a quick method by placing the sample vertically or at a small inclination. Generally, it can be considered that when the sample is exposed at an angle of 45°, the damage speed of the coating film is one and a half times faster than when it is exposed vertically. But this is only true when there is no dust in the air (for example, ocean, multi-village air), because if the air contains ash, the ash tends to be trapped in the coating film at an angle of 45° damage to the coating (discoloration, loss of gloss and chalking). (Related instruments: aging Test Chamber)

Osterling (HNNJIK Leningrad Station) pointed out that the color paint film facing south is the most severely damaged, while the north facing is the least damaged; the damage speed is faster when inclined at an angle of 45° than in vertical orientation. A lot faster when placed. If it is placed in a horizontal position, a large amount of dust will accumulate on the surface, thus delaying the damage of the coating film.

It should be realized that if there is no dust in the air, the paint film will be damaged more severely if it is placed on a horizontal surface. (Related instrument: air quality Detector) In addition to the relationship between the location of the test station, if the paint film sample is placed at an angle of 45° with the horizon and facing south, it can be considered that it is under natural conditions. It may reach The fastest test (OCT10086-89 test method 38). Although it takes a relatively long time to test the vertical coating film, it is also of great significance, because the test of the appropriate sample is close to the service conditions of many coating films on the vertical surface.