Source： Link Testing Instruments Co.,Ltd
The coefficient of friction is an important indicator for evaluating the smoothness of the inner and outer sides of packaging materials. Through testing, it can ensure smooth transportation and packaging on high-speed production lines to meet the needs of efficient and smooth production of products and good packaging quality. If the friction coefficient is too large, the packaging film will not be drawn smoothly, and the sealing will be uneven, which will reduce the production efficiency and increase energy consumption; if the friction coefficient is too small, the packaging film will slip and deviate, which will cause the production line to cut off and cause the company. Huge losses. Therefore, in order to solve the problem of poor rolling of cake plastic composite film packaging, food companies first need to strengthen the inspection and acceptance of the friction coefficient of cake film, and find problems from the source to solve problems before they occur.
Test method and instrument
This article refers to the domestic testing standard for the coefficient of friction of flexible plastic packaging as GB 10006-1988 "Method for Measuring the Coefficient of Friction of Plastic Films and Sheets".
This test uses the LTCOF-05A friction coefficient tester independently developed and designed by Link Testing Instruments co.,Ltd
Test principle: The two surfaces to be tested are placed in contact with each other. Under a certain contact pressure, when the two surfaces move relative to each other, record the maximum resistance (ie static friction) of the two contact surfaces at the beginning of the relative movement and the two contact surfaces The resistance when the speed moves relative to the speed (ie dynamic friction). The coefficient of static friction and the coefficient of dynamic friction are the ratios of static friction, dynamic friction, and normal force applied perpendicularly to two contact surfaces, respectively.
Test sample and test process
Test sample: Cake plastic composite film packaging roll film provided by a food company.
Experimental procedure:
(1) Along the longitudinal direction of the sample, evenly cut out 3 samples of the two specifications of 6.35 cm × 10 cm and 25 cm × 13 cm, and take out 1 sample from each sample to form a set of samples. Form 3 sets of samples.
(2) Mount the 6.35 cm × 10 cm cake plastic composite film sample on the slider with the inner surface of the sample facing down, and spread the 25 cm × 13 cm cake plastic composite film sample on the test platform. With the outer surface facing upwards, fix it with tape or sample fixing device. A system for testing the coefficient of friction between the inner and outer surfaces of the sample is formed. During the clamping of the sample, the hand cannot touch the test surface of the sample, and the sample should be flat and free of wrinkles.
(3) Connect the slider and the force sensor with the connecting device, and then place the slider lightly on the middle part of the sample fixed on the test platform so that the sliding direction of the sample is parallel to the test direction.
(4) Set the equipment parameters, select the test mode, and start the test.
(5) Click the start option to start the test. The equipment automatically calculates the friction coefficient and displays the test result according to the force value change during the test.
Test results and analysis
The average values of the friction coefficients of the samples tested in this article are respectively: the static friction coefficient is 0.312, and the dynamic friction coefficient is 0.435.
From the test results of the cake plastic composite film sample, it can be seen that the dynamic and static friction coefficients of the samples are higher than the normal value, and the dynamic friction coefficient is abnormally higher than the static friction coefficient. This is the main reason that the cake plastic composite film does not roll smoothly. The LTCOF-05A friction coefficient meter is a cost-effective testing equipment. The equipment is easy to operate, and the test results are highly accurate and repeatable. It can accurately reflect the rolling quality problems of the cake plastic composite film packaging and unwinding process.
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