In addition to the sealing function of zippers in daily life, of course, there are other functions. In the era of composite packaging bags, most of them are equipped with zipper bags, which is very convenient for us to store food.

      Consumer-friendly convenience food has a local flavor that can only be circulated through packaging, allowing famous foods from around the world to communicate with each other. Plastic zippers can be used to increase People's Daily food variety.

      With the development and popularization of various new materials. And the development of automated weighing and packaging equipment technology. Pharmaceutical packaging materials have become a new focus of competition. Many advantages of plastic zippers have been shown in health food packaging, and packaging forms have emerged in endless stream, such as blister packaging, strip packaging, aluminum foil packaging, bag packaging, soft bottle packaging and other materials.

      On the basis of the development of packaging industry, the packaging of commodities has developed accordingly. From simple paper packaging to single-layer plastic film packaging, plastic zippers developed into the widespread use of composite materials.

      Chinese composite film started in the late 1970s, from the early to the middle of 1980s, our country began to introduce some extruders, film blowing machines, printing presses, the production of simple two or three layers of composite material.

      Food enterprises should require packaging enterprises to use packaging films that meet national standards. If the material of the composite bag wants to use the green environmental protection type, do not use the dry composite plastic packaging plastic zipper containing benzene and other harmful substances, because its solvent is easy to penetrate the contaminated food.

      A certain blowing ratio and traction ratio are conducive to the improvement of heat sealing strength, but the blowing and traction of thin films actually make the molecules enter the high elastic state to produce orientation, accelerate and promote crystallization.