Primer-free pre-coated film usually consists of a multi-layer structure, including an affinity layer (coating surface), a core layer and a non-coating surface layer (the side without an affinity layer).
Material composition
Affinity layer: This is a layer formed on the surface layer of the biaxially oriented polypropylene film, which can be fused with materials such as polyvinylidene chloride, acrylic acid or modified polyvinyl alcohol through co-extrusion technology. The extrusion thickness of the affinity layer is usually between 1 and 10 microns, and it can be located on the upper surface, lower surface or both of the upper and lower surfaces of the film. The affinity layer is made of a mixed material consisting of polypropylene homopolymer, polyolefin plastic body and anti-sticking agent.
Core layer: It is composed of homopolymer polypropylene.
Non-coating surface layer: This is the side without an affinity layer, and is made of a mixed material consisting of polypropylene homopolymer and anti-sticking agent.
Technical features
No primer required: The biggest feature of Primer-free pre-coated film is that it can achieve good coating adhesion without the use of primer. This solves the environmental pollution and cost problems caused by the use of primers in the production process of traditional coated films.
Environmental protection and energy saving: Since the primer pre-coating process is omitted, the product is more environmentally friendly during the production process and also helps save energy.
Good coating adhesion: Although no primer is used, the design of the affinity layer enables the film to still maintain good coating adhesion and meet various application requirements.