Black and white film is mostly black and white co-extrusion film, often used as liquid milk and other liquid food packaging box, with a certain barrier, light blocking and flexibility is good. In the whole process of the specific canning production bag, some PE black and white film roll film with its friction coefficient is not suitable for the standard value or the friction coefficient of each part is not symmetrical, it is very easy to have the product quality problem that the roll is not smooth, so it is necessary to choose the friction coefficient instrument to carry out the detection of the friction characteristics of the roll film appropriately. This experiment scientifically studies the harm of the friction coefficient of PE black and white film to the whole process of unwinding, explains the whole process and principle of the friction coefficient tester, and can provide technical reference for the relevant manufacturing industry in the detection level of raw material friction coefficient.

Generally speaking, PE black and white film is PE black and white co-extruded film, which is mostly used for liquid milk, liquid seasoning and other commodities. It is a composite bag made by using a three-layer or double-layer co-extrusion method, using LDPE and LLDPE as basic epoxy resin raw materials, and adding black and white masterbatch to co-extrusion and blowing. Nowadays, in order to obtain higher barrier property, EVOH, PA and other barrier epoxy resins will be added to co-extrusion, and mLLDPE epoxy resin will be added to obtain excellent flexibility and thermal sealing actual effect. Therefore, the raw material structure used by PE black and white film can be selected and adjusted according to the packaging contents and storage period, so that it has barrier property, heat sealing property, light shading property and flexibility.

In order to ensure the smooth running of PE black and white film on the high-speed automatic filling machine, a certain proportion of slippery agent and brightener are added when making film, so as to reduce the friction coefficient of black and white film and avoid adhesion, but too much slippery agent will harm the heat sealing and the adhesion color fastness of the ink printing layer. The smoother the PE black and white film is, the smaller the friction coefficient is, but if the friction coefficient is too small, it is easy to run off or in the direction when unwinding; The coefficient of friction is too large, it is easy to cause unwinding smooth, resulting in reduced productivity. Therefore, how to ensure that the smoothness of the applied PE black and white film is not considered in the production line requirements, it is necessary to use testing instruments to detect the important characteristics of its friction coefficient. In addition, the immediate monitoring of the friction coefficient is more conducive to improving the processing technology of seasonings such as smooth agents, and appropriately guiding the production and processing of PE black and white film.

PEP Lide film manufacturer inspection method:

The friction coefficient of soft raw materials is mostly tested with a friction coefficient instrument. The test surface to be tested is flattened and touched under a certain working pressure (if the friction coefficient between a certain side of the sample and the middle of the stainless steel plate is detected, the test surface is directly contacted with the middle of the thick steel plate), and then the two surfaces are relative moved. The dynamic friction coefficient and static friction coefficient caused by the whole process of moving were detected.

1. Experimental instruments

MXD-02 friction coefficient meter, the test can bear the load working pressure range of 0~5N; The travel arrangement of the relative displacement can be considered 70mm and 150mm; Guide slide quality 200g(standard quality), other quality guide slide can be customized; The experimental rate is divided into 90mm/min and 150mm/min, and other rates can be adjusted if necessary. The dynamic and static friction coefficient of the specimen can be measured in one experiment. Instrument and equipment test cabinet table and detection guide slide have been solved by demagnetization and remanent magnetic test, which reasonably reduces the deviation of functional test.

The machine considers a variety of national and national standards: ISO8295, GB10006, ASTMD1894, TAPPIT816. It can be used to test the static friction coefficient and dynamic friction coefficient of plastic film and sheet, vulcanized rubber, paper, cardboard, packaging bags, power cables and optical cables with metal composite composite belts, conveyor belts, wood, plating, brake discs, wipers, shoes, tires and other raw materials. In addition, it can also be expanded to measure the smooth properties of skin care products, eye drops and other daily chemical products.

2. Sample preparation

Evenly cut 2 samples of 8cm× 20cm on the sample, the sample should be flat, free of wrinkles and scars that will change the friction characteristics, and the test surface of the sample should be free of dust, fingerprint identification and all foreign chemicals that will change the surface characteristics. Prepare three pairs of samples in advance in accordance with the said provisions. Under the normal natural environment of 23℃ and 50%RH, the adjustment condition is more than 16 hours.