Most thermoplastic plastics can be produced by blow molding. The blow plastic film is a thin film produced by squeezing the plastic into a thin tube, then blowing the plastic in compressed air and then cooling the mold. The film has the properties between the directional film and the casting film: the strength is better than that of the casting film, and the thermal sealing ability is better than that of the casting film. It is worse than the casting film.
The three layer co extrusion blown film machine occupies an important industry status in the plastics industry. At present, most manufacturers of membrane blown machines in China are not suited to the market demand and the technology needed to improve the production of membrane blower. In order to get quality controllable plastic bag products, the film blowing machine must control every processing step.
The quality of film blowing machine and film blowing technology can affect the quality of plastic film, so a good film blowing machine can show good market adaptability in the process of producing film, thus improving production efficiency, promoting the development of enterprise productivity and social civilization progress.
At present, a lot of plastic film equipment in China is a single layer film blowing old equipment purchased early. There is a widespread technology backwardness, serious aging of equipment, poor adaptability of raw materials, high energy consumption, low production and poor quality of film, so it must be replaced. In recent 5 - 6 years, domestic plastics factories have purchased a number of two - three layer co extrusion film blowing equipment, but the number is far from the needs of the production and development of multi-layer co extruded plastic film.
In order to meet the needs of some special functions of plastic film packaging materials in the process of production, a variety of characteristic materials (such as air permeability, waterproof, thermal insulation, toughness, etc.) are blown and extruded together to form a multi-functional plastic film, and a multi-layer coextrusion blow film machine has been developed.