Talk about the test steps of the machine roll film

1 Test principle The two test surfaces are placed flat together, and the two surfaces are moved relative to each other under a certain contact pressure, and the maximum resistance (ie static friction) of the two contact surfaces at the beginning of the relative movement is recorded and the two contact surfaces move at a certain speed. The resistance at the time (ie dynamic friction). The coefficient of static friction and the coefficient of dynamic friction are respectively the ratio of static friction, dynamic friction and normal force applied perpendicularly to the two contact surfaces. 2 Test procedure MXD-02 friction coefficient meter can accurately test the friction performance of each movement link between the test surfaces. The high-intelligence software controls the test and the equipment is easy to operate: 　　 determine the test surface. The friction between the black surface) and the outer surface (ie the printing surface).　　 The outer surface of a sample is upward, and it is fixed flatly on the horizontal test bench of the instrument. The length of the sample and the test bench should be parallel.　　 Place the inner surface of the other sample downward, wrap the test slider, and fix the sample on the edge of the slider with the device's own spring.　　 Place the sliding block with the sample on the center of the sample on the test bench without impact, and make the test direction of the two samples parallel to the sliding direction and the force measuring system is just not stressed.　　 After setting the instrument parameters and selecting the test mode, start the test.　　 During the test, the two samples are in contact for 15 s, and then move relative to each other with the activated instrument. At the end of the test, the system automatically records the first peak value of the force curve as static friction, and automatically calculates the average value of the force within 6 cm of relative movement as dynamic friction and the corresponding static and dynamic friction coefficients.　　 Close the software program and the instrument power. The static friction coefficient of 　　 fresh milk PE black and white film is 0.264, and the dynamic friction coefficient is 0.201. The relative deviation of the test results among the three sets of parallel samples is less than 10%. From the test data of the PE black and white film, the static friction coefficient of the plastic film is larger than the dynamic friction coefficient, which is in line with the normal law of plastic film, and the dynamic friction coefficient is more related to whether the film is unwinding smoothly. The size and uniformity of the dynamic friction coefficient of the fresh milk PE black and white film sample are relatively suitable, which can ensure the smooth unwinding of the roll film. Label: machine roll film