Can plastic coating adhesion testing be done with a paint film scratcher?

How to test the adhesion of plastic coating? Can I use a paint scratcher? The answer is yes.

The paint film cross-cutting device is an adhesion testing instrument equipped with different number of teeth and blade spacing cutter heads for cross-hatching. The applicable coating thickness and test object are determined by the blade teeth spacing and the number of blade teeth. . Generally, the tooth spacing is 1mm, 2mm, 1.5mm, 3mm, and the number of teeth is 6 teeth or 11 teeth.

For the substrates of the tested samples, there are soft substrates and solid substrates, and the specifications of the cutter heads are different. A solid substrate refers to a solid substrate such as metal, while a soft substrate refers to a substrate with a soft substrate such as plastic. Plastics are soft substrates, which can be tested with a paint film cross-hatcher. Currently, more imported brands are used for coating tests on soft substrates. Domestic ones are mostly used for testing solid substrates such as tinplate, metal iron, and glass.

So what brand and model of paint film scratcher to choose for the adhesion on the plastic coating? In general, the 6-tooth 2mm pitch cutter head conforming to ISO2409 and ASTMD standards can be used for coating adhesion testing on soft substrates such as plastics.

Such as TQC's VF1842, SP1691, SP1681 models. Not only soft substrates can be tested, but also hard substrates can be tested, but the film thickness range of the test is different. Comply with ISO2409: 0~60um ( soft substrate), 61-120pm (hard substrate); ASTM D3359: 50~125 μm (hard substrate).

There is also the German BYK 5122 paint film scratcher, with 6 teeth and 2mm blade spacing, which can be used to test the adhesion of plastic coatings. The thickness of the coating tested ranges from 0 to 60 μm. The BYK5122 model also complies with ISO2409 and DIN 927-3 standards, and the cutter head is made of alloy steel.

Of course, there is also a brand like Elcometer, which also has models that can test soft substrates. Generally speaking, to test the coating adhesion on soft substrates such as plastics, the thickness of the coating should not exceed 60 μm. Generally, the distance between the teeth of the cutter is 2 mm. Of course, the cutter head must meet the standard design to ensure the accuracy of the test. accuracy.