What is the reason for the horizontal wrinkles after the aluminum foil bag is compounded? (1)


1. The tension of the two base membranes is not suitabl […]

1. The tension of the two base membranes is not suitable for compounding. One of the base membranes is strong and the other is small. After being compounded, the original film with high tension shrinks, while the other film with low original tension does not shrink, causing relative displacement and wrinkles.
For example, when BOPP and aluminum foil are used for compounding, the BOP is glued into the drying tunnel to heat and dry. If the unwinding tension is large, it is stretched very tightly, and it is often stretched when heated in the drying tunnel. The unwinding tension of another substrate aluminum foil is unlikely to be too large, and its elongation is very small. When it is compounded, it will be cooled and cause the BOPP film to shrink, resulting in wrinkles, aluminum foil protrusions, and horizontal aluminum foil protrusions. "tunnel". If this is the reason, the unwinding tension of the two base films should be adjusted to make them adapt to each other.
In addition, lowering the temperature of the drying tunnel is also a way to solve the tunnel effect, because the higher the temperature, the greater the elongation of the film, the more shrinkage after cooling, and the greater the chance of wrinkles, but it is necessary to ensure residual solvent The quantity is qualified, so we must take care of each other.
2. There are too many residual solvents, insufficient drying of the adhesive, and too small adhesion
A small adhesive force will provide the possibility for the mutual displacement of the two substrates. As long as the tension between the two substrates is different, one kind of film will shrink a little more, and wrinkles will also occur. This must be solved by controlling the amount of residual solvent.
3. The amount of glue applied is insufficient and uneven, causing poor adhesion
Uneven gluing can cause wrinkles in local areas. It is necessary to check whether the gluing amount of the compound is sufficient and uniform. If there is any problem in this respect, the glue applicator and glue concentration should be improved to make it reach Until requested.

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