Packing bags of milk packaging requirements and material structure

Milk, is one of the most favorite drinks in People's Daily life. Its nutrition is very high, is rich in calcium, still has a lot of chemical elements, except calcium iron, phosphorus, zinc, potassium, etc. Because the milk is fresh food drink, to the health, the bacteria are very strict, temperature, etc, therefore, of milk packaging printing also has a special request, this makes the milk is different from other bags printing printing technical characteristics. For the selection of milk packaging film, must conform to the packaging and printing, processing, shipping and health aspects of requirements. Milk packaging requirements ( 1) The pollution prevention, safety is the most basic request in the packing bags of milk, milk with rich nutrition and balance, is the ideal of microbial culture medium, highly vulnerable to microbial infection and metamorphism. So the packaging of milk to be able to prevent the infection of microorganism, put an end to the pollution of poisonous and harmful substances at the same time, guarantee the health and safety of the products. （ 2) Water because of liquid milk, packaging to ensure that the content of milk, milk cannot seep, so the packing should be has a good waterproof performance. （ 3) Fresh milk is a good natural drink, in the process of transportation storage, to ensure that the milk nutrients and a relatively stable state of the organization, guarantee the quality of milk. Many of the components of milk are easily influenced by outside factors, and therefore require packaging can effectively delay of nutrients. Requiring milk packaging should have high resistance capability, high shading sex, in order to protect the milk nutrients are not lost, ensure that the value of milk. Milk packaging film types according to its layer structure, basically can be divided into three. 1, simple general for single-layer film, it is by all sorts of polythene adding a certain proportion of white masterbatch, the blown film production equipment. This kind of packing film is a block structure, using pasteurization, 85℃/ 30分钟) For hot filling, short shelf life ( About 3 days or so) 。 2, three layer structure of the black and white co-extrusion blown film line milk bags with LDPE, LLDPE, EVOH, MLLDPE, such as resin, with black and white masterbatch co-extrusion blown into a high-performance composite membrane. Heat sealing inner add in black masterbatch have the effect of blocking the light. This kind of packaging film is made of super high temperature sterilization and hydrogen peroxide sterilization method, room temperature shelf life can be up to 30 days. 3, the structure of the five layers of black and white co-extrusion blown film line blown film increased barrier layer in the middle ( By EVA, EVAL high barrier property of resin) , therefore, this kind of packaging film belongs to the sterile packaging film with high barrier property, has a long shelf life, room temperature can be saved about 90 days. Three layer and multi-layer co-extrusion blown film line black and white have excellent heat sealing performance and avoid oxygen resistance, light resistance with low cost, easy to transport, storage space is small, strong practicability, etc. 4, the high barrier transparent milk film all transparent packaging is one of the biggest advantages can make consumers through milk bags intuitive to see their products they buy. The same product, if there is a transparent packaging and non transparent packaging for consumers to choose two kinds of packaging form, most consumers are more willing to choose transparent packaging. Such milk membrane structure of PE/PVA/PE, in India, now commonly used thickness is 90 um. Using PVA high barrier coating as barrier layer, making the nano inorganic materials and organic polymer materials better fuses in together, the characteristics of two types of blocking materials to more fully play.