In the paint and coating industry, paint attachment testing is often used to determine whether the paint or coating will adhere properly to the substrate used. There are several different tests to measure the resilience of paints and coatings of the substrate: cross-cut test, adhesion abrasions, pull-off tests, and others.
Video Paint adhesion testing
Scrap Adhesion Test
The frictional adhesion test measures the determination of organic coating adhesion when applied to a smooth flat panel surface. This helps in providing a relative assessment for a number of coated panels showing significant differences in adhesion. The material under test is applied to a uniform thickness for flat panel, especially a kind of sheet metal. When the material has dried adhesion is determined by pressing the panel beneath the rounded stylus which is loaded with increasing amount of weight until the coating is removed from the surface of the substrate.
Maps Paint adhesion testing
The pull-off test
The adhesion of layers or of several coated samples of each paint product is measured by assessing the minimum tensile stress required to release or break a layer perpendicular to the substrate. Unlike the other methods, this method maximizes the tensile stress, therefore the result may not be comparable to the others. This test is performed by securing the loading of the equipment (doll) perpendicular to the surface of the coating with adhesive. Then the test device is mounted on the loading equipment and then aligned to apply a voltage perpendicular to the test surface. The applied force is gradually increased and monitored until the release coil is removed, or the predetermined value is reached.
Cross-cut test
Cross-cut tests are a method for determining the resilience of paints and coatings to separate from the substrate by utilizing a tool to cut the right angle grille pattern into a layer, penetrating all the way to the substrate.
A quick pass/fail test can be completed through this method. When testing multi-coat systems, the determination of resistance to different layer separations from each other can be achieved.
There are two methods described in ASTM Specifications;
Test Method A
X-cut is made through the film with the carbide end tool to the substrate. The pressure-sensitive band is applied on the cut. The tape is smoothed into place using a pencil eraser above the incision area. The tape is removed by pulling it back quickly with a 180 ° angle. Adhesion is rated on a scale of 0 to 5.
[0 - Over 65% of area deleted & amp; 5 is 0% area removed]
Test Method B
The crosshatch pattern is made through the film to the substrate. The loose flakes are removed by brushing with a soft brush. The pressure-sensitive band is applied over the cut of the crosshatch. The tape is smoothed into place using a pencil eraser above the incision area. The tape is removed by pulling it back quickly with a 180 ° angle. Adhesion is rated on a scale of 0 to 5. [0 - Over 65% of the area is removed & amp; 5 is 0% area removed]
See also
- Painters and decorators
Note
Source of the article : Wikipedia
0 Comments