What are the reasons for the wrinkle of the composite film?

Lateral wrinkles appear in the compounded product, especially at the ends of the roll. This kind of wrinkle is formed by one substrate being flat and the other being raised.”tunnel”form the majority. 1, On the material, the initial adhesion of the adhesive is insufficient; the surface tension of the substrate is insufficient. 2, In terms of technology, the tension of two kinds of base film rolls is not suitable, one is too large, and the other is too small. E.g:BOPP/AIcompound, such asBOPPThe tension is too high, and the drying tunnel is heated and elongated.AIThe tension cannot be large, and the elongation rate is small, after compounding,BOPPCooling shrinkage causes aluminum foil protrusions, horizontally striped”tunnel”;The amount of glue applied is insufficient and uneven, resulting in poor adhesion and local wrinkles; the winding tension is small, the roll is not tight, and there is relaxation after lamination, which provides the possibility of shrinkage for the substrate to be shrunk. If the winding tension is large, the rolling tension is large, the rolling is tight and compacted, and immediately sent to the curing room for curing, even if the process is not suitable, there will be no wrinkles; the oven temperature is too low and there is no ventilation, and there is too much residual solvent glue Insufficient drying of the adhesive and insufficient initial adhesion provide the possibility for the mutual displacement of the two base films.