Biaxially oriented polypropylene film (BOPP) is generally a multi-layer co-extruded film, which is made by co-extrusion of polypropylene particles to form a sheet, and then stretched in both vertical and horizontal directions. Due to the orientation of the stretched molecules, the film has good physical stability, mechanical strength, air tightness, high transparency and gloss, toughness and wear resistance.
It is a widely used printing film, and the thickness is generally 20-40 μm. , The most widely used is 20 μm. The main disadvantage of biaxially oriented polypropylene film is poor heat-sealability, so it is generally used as the outer film of composite film.
For example, it has ideal moisture resistance, transparency, strength, stiffness and printability after being composited with polyethylene film. It is suitable for Contain dry food. Because the surface of the biaxially oriented polypropylene film is non-polar, the crystallinity is high, and the surface free energy is low. Therefore, its printing performance is poor, and its adhesion to ink and adhesive is poor. It needs to be surfaced before printing and lamination. deal with.
Disadvantages: The elongation is lower than that of PP, the heat sealing performance is poor, it is not easy to seal when used independently, and it is generally compounded with PE and other films with good heat sealing properties when used.
Advantages: high tensile strength, good barrier performance, and high transparency.