PET film is a more comprehensive performance packaging films. Its transparency, gloss; good tightness and Paul fragrance; moderate moisture, water vapor transmission rate decrease at low temperatures. PET film of excellent mechanical properties, their strength and toughness is the best of all thermoplastics, much higher tensile strength and impact strength than the average film; and very good strength, dimensional stability, suitable for printing, paper and other secondary processing . PET film also has excellent heat resistance, cold resistance and good chemical resistance and oil resistance. But its impatience alkali; easy method with static electricity, there is no proper anti-static, so attention should be on the packaging of powdered materials. With the development of special function films, new uses polyester films are also emerging. It can produce as mobile phone LCD protection film, protective film LCD TV, mobile phone keypad. PET protection film for mobile phones, compared with other plastic packaging has many excellent properties: excellent gas barrier, wet, poise and other high barrier resistance, good chemical stability; with other plastics that fall high toughness properties, tensile strength, impact strength is also high, but also has good wear resistance and resistance to vacuum bag fold compared with the ordinary bags, has a relatively superior performance, both to extend the shelf life of goods, you can keep it taste the same. This is because the bag has a special functionality. The vacuum bag must have a very good sealing properties, namely air and moisture barrier properties, the barrier of the ingredients are water, oxygen and carbon dioxide, so that goods in a completely isolated environment protected, this high barrier made of co-extruded film, a relatively stable nature