Milk packaging film choice standard and the test items

The quality of the milk packaging film materials mainly from to the functional requirements, including the oxygen, moisture, avoid light, sealing, peculiar smell, Solvent residue) Safety factors, as well as to assess their printing, computer performance, such as mechanical properties, heat sealing performance, surface sliding may just as well, such as printing quality. In order to adapt to the milk filling and printing requirements, demand for milk packaging film mainly has the following several aspects. 1, smooth milk packaging used black and white film, PE milk packaging film should have appropriate internal and external surfaces of the sliding may just as well, to ensure its good opening and the high-speed production line can be transmitted smoothly without packaging. Milk packaging film should have good internal and external surface smooth, to make sure it can smoothly in high speed automatic filling machine filling, therefore, milk packaging film on the surface of the movement to lower friction coefficient, the general requirements of 0. 2 to 0. 4 milk packaging film smooth sex is mainly implemented by adding a smooth agent. 2, tensile strength, because the plastic milk packaging film should be in the process of filling the role of mechanical strain from automatic filling machine, therefore, request milk packaging film must have enough tensile strength, prevent the automatic filling machine under the action of tension and be pulled apart or cause drag mark. Choose low melt index in the process of blown film of LDPE or HDPE particles, so it is very beneficial for improving the tensile strength of the polyethylene milk packaging film. 3, the surface wetting tension in order to make the printing ink can be spread out smoothly, wetting and polyethylene plastic milk packaging film surface adhesion, for milk packaging film should reach a certain standard, the surface tension of the need to rely on the corona treatment and achieve higher wetting tension, otherwise it will affect the ink on the surface of the milk packaging film, adhesion and fastness, which affects the quality of the print. The surface tension of the general requirements of polyethylene milk packaging film should reach more than 38 dyne, better if you can reach more than 40 dyne. 4, heat sealing by the sealing performance testing to ensure that the entire product packing seal is in good condition, prevent because of the bad product sealing performance and appear leakage caused by packaging. Milk packaging film automatic packaging is the main concern of the leak sealing, virtual and lead to broken bag issue, therefore, milk packaging film should have good heat sealing bag, have a good seal is broken, there is a wide range of heat sealing, so that the packing speed change, heat sealing effect is not affected by too much, MLLDPE also often used as the heat sealing layer, to fully guarantee the heat sealing conditions of stability and can be heat sealing. That is to say, is to ensure the heat sealing, and to be able to block a, make molten resin won't stick. For milk packaging film structure design, can according to different packaging contents and its shelf life, the select of the structure of the packaging film. 5, residual milk bags will be used in the printing process in the process of production of organic solvents, such as ethyl acetate, butanone, butyl acetate, ethanol, isopropanol, etc. These more or less residual organic solvent in packaging materials, if contain high solvent residue of packaging materials used for packing of milk, will produce packaging odor and even endanger people's health. So you must to test the solvent residue. Before sale, detection and control of milk packaging film, it is very necessary. Different people different demand for nutritional value of products, allows firms to continuous efforts to develop new products. At the same time, complying with the development of the society, the packaging of milk is in constant improvement, continuously development, constantly update that meet the needs of the consumers.