Produced by multi-layer resin melt extrusion or vacuum evaporation process
The production process of rainbow film is mainly divided into two categories, as follows:
1. Multi-layer resin melt extrusion process
This is the current mainstream rainbow film production technology, and its core steps include:
Material selection: Use two or more resins with different refractive indices (such as PMMA, PET, PBT) as raw materials.
Layered superposition: Through co-extrusion technology, the resin is melted and superimposed in sequence to form a nano-scale film structure of more than 100 layers, and each layer is only a few hundred nanometers thick.
Optical effect: The multi-layer structure produces a magical effect through the interference and reflection principles of light, similar to the color principle of mother-of-pearl or peacock feathers.
Application extension: The finished product can be further compounded with other materials (such as PET film, coated paper, non-woven fabrics, etc.) for packaging, decoration and other fields.
Technical advantages: The product has high uniformity and good strength, and the imported equipment of the biaxial stretching process has better performance.
2. Vacuum evaporation process
This is a patented technology, mainly used for the production of rainbow films with special needs:
Vacuum environment: Place the film to be coated in a vacuum chamber, and heat the evaporation medium doped with metal powder (such as aluminum, titanium, etc.) through an evaporation boat to deposit metal vapor on the surface of the substrate.
Multilayer coating: Replace different metal powders and repeat evaporation to form a multi-layer metal oxide coating, and achieve a color change effect through light interference.
Cooling and winding: After coating, the film is solidified through the cooling system and rolled up by the winding roller.
Application scenario: This process is more suitable for high-precision optical films (such as colorful glass interlayers) or anti-counterfeiting packaging needs.
Supplementary explanation
Historical development: The rainbow film technology was originally developed in the United States and introduced to Taiwan, China in the late 1980s. After 2005, the mainland began to produce it independently.
Process difference: The melt extrusion process is suitable for large-scale production of general rainbow films, while the vacuum evaporation process is more suitable for customized high-value-added products.
