The level of adhesion of an enamel coating cannot be judged directly by its surface appearance. The interior is hidden thanks to the combination of enamel coating and steel. Generally, a paint film impact Tester is used to test the adhesion level of the coating.
Test Principle
Due to free fall, the test weight creates a cavity in the enamel-coated surface. The enamel in this area was cracked and the impact of the impact was checked visually. The impact effects are rated according to the scale below. Record this result as the Adhesion Value for the Enamel.
Test Methods
Use the impact Tester on the picture. The impact device has a specific diameter with a specific weight and a spherical tip. The enamel-coated plate is placed on a ring metal mold.
Structural specification
A pipe with a length of 1 m and an internal diameter of 21 mm is placed completely vertically on a suitable rack. The channel opens on one side of the pipe. To fix the weight, several sections are placed at different heights of the pipe.
The weight of the impact device inside the pipe is 2 kg. The tip of the device is designed as a hemisphere with a diameter of 10 mm. Adjust the distance between the end of the pipe and the metal mold so that the power of the vertical load weight does not drop.
The distance between the impact weight and the metal plate to be tested is 0.75 m. The impact site was released from this location, so the impact energy was determined to be 15 kj. Impact energy = drop height X impact weight X gravity constant.
The results can indicate the level of adhesion of the enamel coating to the steel plate. There are mainly 5 levels:
