Film lamination refers to the process of laminating two or more film materials with different properties together through adhesives or other methods to form a composite film material with new functions and properties. Film composite process is an important part of the film material processing technology, in packaging, agriculture, construction, electronics and other fields have a wide range of applications. In this paper, we will introduce 3 common film composite process methods in detail
Composite film production is mainly coated, laminated, co-extruded composite three processes.
1. Coating process
1.1 principle
Mostly used in paper-plastic coating, or plastic-plastic coating, such as waterproof layer coated paper, which is the earliest composite method. Paper-plastic coating is the product of this process (paper adhesive PE film). Commonly used coating methods are: brushing, dip coating, scraping, roller coating, spraying, cast coating, powder coating and so on.
1.2 Advantages
Flexible process: coating composite can be adjusted according to the need to adjust the thickness of the coating layer and coating method, to adapt to different application requirements.
High value-added: the coating can give the substrate new functions, such as waterproof, conductivity and optical properties.
Diversified coating materials: a variety of coating materials can be used, such as polymers, metal oxides and nanomaterials.
1.3 Applications
Nowadays, it has been developed to coat PVDC oxygen barrier on BOPP film, which is used for packing meat and cigarettes, etc.
2. Laminated Lamination
2.1 Principle
With the help of adhesive media, two or more layers of film, overlapping composite method. Processes are wet, dry, hot melt, extrusion and thermal lamination method. Which is used for plastic film lamination to the dry method. That is, the adhesive coated on the surface of the substrate, remove the solvent, and another substrate composite. This method is suitable for a variety of film composite, but to choose the right adhesive for different films.
2.2 Advantages
Multifunctionality: Laminated composite can combine the advantages of a variety of materials together to form a composite film with a variety of functions.
Reprocessability: the products of laminated composite can be subsequently processed, such as printing, cutting and thermoforming.
Cost-effectiveness: the laminated composite process is relatively simple, with low equipment investment and running costs.
2.3 Application
Laminated composite films are widely used in packaging, construction and household fields. For example, aluminum foil laminated composite films are used in food packaging to provide excellent barrier properties and freshness retention.
3. Co-extrusion Lamination Process
3.1 Principle
This method is more advanced and of course the process operation is more complex. Through two or more extruders, the different resins are extruded separately, through a head, composite into an all-composite body, that is, made of a composite film.
3.2 Advantages
Efficient production: co-extrusion composite process can be formed in a production process at the same time multi-layer film, improve production efficiency.
Good interlayer bonding: due to the layers of material in the high temperature at the same time extrusion, has a good adhesion.
Material diversity: different polymer materials can be selected to achieve specific properties such as barrier, strength and flexibility.
3.3 Applications
Co-extruded composite films are widely used in food packaging, pharmaceutical packaging and industrial packaging. For example, high barrier co-extruded composite films are often used in food preservation packaging to extend the shelf life of food products
The selection of film composite process should be based on specific production requirements and product performance requirements to determine. The following factors should be considered when selecting a film lamination process:
Type and nature of the film material
Performance requirements of the composite material
Production efficiency
Production cost
Environmental impact
Conclusion
In recent years, with the progress of science and technology, the film lamination process continues to develop and innovate, and new composite processes and technologies continue to emerge. The application range of film composite process is also expanding, providing more possibilities for the application development of film materials.