From what aspects to measure the quality of the protective film
Nov 15,2022 | Jeff
In order to make the evaluation of the protective film have a rough standard, we analyze the protective film from several angles.
What the protective film needs to do is to provide a layer of insurance for the mobile phone without affecting the original user experience (of course, it is also possible to improve the original user experience), and to protect the screen when the screen may be broken or scratched. Therefore, from the perspective of protection, there is quality evaluation of anti-fall, and the center and edge of the protective film are tested by the falling ball meter and the pressure gauge respectively. From the point of view of use experience, there are three evaluations of anti-fingerprint effect, wear-resistant effect and light transmission effect.
Falling ball test for quality evaluation
This experiment mainly tests whether the tempered film can protect the screen of the mobile phone well, using a falling ball tester. This instrument is to place a falling ball at a certain height, and then drop it on the tempered film. The higher the height of the falling ball, the better the anti-drop effect of the tempered film. Usually from low to high, increase the height by 5cm or 10cm in turn, and record at what height a falling ball can damage the protective film. The current standard on the market is to withstand a 50g ball falling from a height of 1.2 meters without any damage.
Anti-fingerprint effect test for quality evaluation
In fact, it is a test of the initial effect of the oleophobic layer. The hydrophobic and oleophobic effect is the same as water droplets falling on lotus leaves. Because the surface of the lotus leaf has a nano-level natural air interlayer, the water also has little friction on the lotus leaf, so it will not stay on the surface of the lotus leaf. Therefore, there is an oleophobic layer on the screen, the surface friction is smaller, the sliding is smoother, and the oil is not easily contaminated. Use a water drop angle tester. The test is to drop water droplets on the tempered film to see the angle at which the water drops fall on the tempered film. The larger the angle of the water droplets, the better the anti-fingerprint effect, and the smaller the angle, the poorer the anti-fingerprint effect. Currently qualified oleophobic coatings must have a water drop angle of at least 105°.
Friction resistance test for quality evaluation
Wear-resistant effect, anti-fingerprint effect after long-term use, use a friction-resistant machine to test, and then measure the water drop angle. The principle of the anti-friction machine is that the surface of the tempered film is constantly rubbed mechanically and electrically. After a long period of friction, the surface of the tempered film is worn, and then the water drop angle tester is used to evaluate the wear. The angle is still large, indicating that the friction resistance effect is good. At present, the qualified oleophobic coating must have at least 3000 times of wire wheel friction and still maintain smooth properties.