Transparency of polyethylene film

The biaxially oriented polypropylene film is made by co-extruding polypropylene particles to form a sheet, and then stretching it in both vertical and horizontal directions. Due to the orientation of the stretched molecules, this film has good physical stability, mechanical strength, air tightness, high transparency and gloss, toughness and wear resistance. It is the most widely used printing film, and the thickness is generally 20-40 μ m, the most widely used is 20 μ m.

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. Pack dry food. Since the surface of the biaxially oriented polypropylene film is non-polar, the crystallinity is high, and the surface free energy is low, 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.