Because of its beautiful appearance, easy-to-use and low cost, soft plastic packaging has been favored by consumers. It is widely used in daily consumer products such as food and medicine. However, due to the limitations of the performance of various single-layer materials, a variety of materials are usually required to be combined to meet the needs of various packaging products. At present, most of the domestic manufacturers of composite technology is dry composite, dry composite process is the early introduction of production technology from Japan and Europe, which is characterized by mature technology, stable quality, wide range of applications. Dry-process compounds, however, also have inherent drawbacks that, due to the large amount of organic solvent used in the production process, can jeopardize the health of the operating workers. In addition, the organic solvent remaining in the packaging film will migrate after contact with the contents of foods, medicines and the like, and eventually affect the health of consumers.
At present, the state pays more and more attention to the safety supervision of food and medicine. Similarly, for the safety of packaging materials, environmental problems also put forward higher requirements. Therefore, for soft plastic packaging, the dry-process compounding process will eventually be eliminated due to its inherent defects. Seeking a healthy, safe and environmentally friendly composite process has become an important issue in the plastic packaging industry. In the 1970s, Germany invented a new type of green composite technology - solvent-free composites. In the 1990s, this technology was introduced to China.