As the previous analysis, the control window of the fingerprint resistant film is very narrow, so the film thickness must be measured immediately after drying to adjust the process parameters at any time. In order to ensure the accuracy of the
measurement data, the production line is equipped with X-ray fluorescence and infrared film measuring instrument to detect the weight of passive film, so as to compare with each other. However, there is a certain deviation between the measurement results
of the two methods. Take the desktop X-ray fluorescence as the standard, and carry out the test results of the infrared film analyzer Amendment. After several verification, the correction values are shown in the table below.
Film weight measured
by X-ray fluorescence (g / m2)
Filmweight measured by infrared thickness gauge (g / m2)
Add 0.10 to the X-ray fluorescence detection value
Add 0.15 to the X-ray fluorescence detection value
Add 0.20 to the X-ray fluorescence detection value
2. Coating performance test of fingerprint resistant board
The fingerprint resistant board generally needs to be coated when it is used. Different coatings can be applied. After the
specimen is baked and cured, the scratch test is used to evaluate the coating adhesion. The space between the marks is 1 mm, 100 × 100 grids. Paste with adhesive tape, and observe the peeling off of the coating. The spraying process is electrostatic spraying,
the electrostatic pressure is about 80kV, the flow rate pressure is about 0.45MPa, and the film thickness is 95-110 μ m; the scratch test is grade 0, and the adhesion is excellent, which meets all the coating requirements of major domestic appliance enterprises.
The specific results are shown in the figure below.
a) Solvent based amino alkyd; b) Seiko ink; c) powder coating
How to control the film thickness of fingerprint resistant board?
The common fingerprint resistant roller coating equipment
is shown in the figure. The roller coater takes materials from the material tray through the dipping roller. The coating roller is located between the dipping roller and the strip steel to evenly apply the coating to the surface of the strip steel.
Selection and detection of film thickness of fingerprint resistant plate
Roller coater has two coating methods: forward coating and reverse coating. The maximum speed of work roll is the same as that of strip steel, which is suitable for thin
coating. The reverse coating method is applied on the surface of the roller, which is convenient for operators to observe the actual coating situation, and is suitable for thick coating. In order to control the film weight of fingerprint resistant passivation
plate within the above-mentioned very small range, it is necessary to change the imported coating roller with high hardness (70hs) to domestic low hardness (60hs) coating roller, and increase the roughness to 0.6-0.8um, so as to ensure greater contact
area and coating ability between coating roller and strip steel, and improve the uniformity of fingerprint resistant film on the whole plate