In the past, the production of composite films in China mostly used the dry or wet composite process of single-layer films. However, due to the stable quality of the products, poor hygiene of the adhesive used, and high cost, they were gradually replaced by multi-layer co extruded films.

Before the 1990s, China mainly used rotary machine heads to produce 2-3 layers of co extruded film, but with development, 3-layer packaging film gradually gave way to 5-layer or even 7-layer film. Is it precisely because of its high cost-effectiveness that domestic plastic processing machinery occupies the market? Most domestic markets may rely on this advantage to enter the international market.

The multi-layer co extrusion composite process is a new type of functional film formed by using multiple extruders to extrude materials in a molten state through special machine heads. With just one processing step, a multi-layer and multifunctional composite film can be made, which can save about 30% of production costs compared to other composite processes. Accompanying and catalyzing this process is the development of domestic multi-layer composite blown film equipment. Currently, about 40% of plastic packaging films in developed countries are produced using the extrusion method for multi-layer co extrusion films, while the proportion in China is slightly lower.

The production of this type of mold has formed some well-known professional manufacturers, whether it is imported or domestically produced equipment, most of which require the introduction of mold heads.

The hot runner plastic film produced by the extrusion method is another major category of products produced by the blow molding process. Although domestic equipment is still insufficient in terms of product accuracy and reliability compared to imported equipment, its price advantage is unmatched by imported production lines. The additive die is the most commonly used die, with advantages such as short flow channels, arbitrary combination of layers, and independent temperature control.

There are multiple key technologies in the production equipment of multi-layer co extrusion blown film, among which the mold head is the most important one.

Introducing hub technology and components is a shortcut for the development of Chinese blow molding enterprises. This film can be configured with different components according to user requirements, achieving different barrier requirements and reducing costs.