The origin of the aluminizing transfer is that the bonding force between the aluminized layer and the substrate is less than the bonding force between the aluminized layer and the glue layer, resulting in a decrease in the overall peel strength of the composite film, resulting in a large amount of aluminized layer from the substrate and to the glue layer Migration phenomenon.

VMCPP and VMPET are the most commonly used aluminized films, and the corresponding composite film structures are OPP / VMCPP, PET / VMCPP, PET / VMPET and so on. In practical applications, the most prone to problems is PET composite VMPET, because it is often used in the middle compound. This is because, as the aluminum substrate, CPP and PET in the tensile properties there is a big difference, PET rigid large, once also with the same great rigidity of the composite material in the curing process of adhesive curing, due to The existence of cohesion, it is likely to cause damage to the adhesion of the aluminum layer, so that the aluminum layer migration occurred.

The main reasons and treatment:

(1) the amount of glue is too large. The amount of glue to be appropriate, the amount of glue is too small, will undoubtedly result in a small composite fastness, easy to peel; but too much glue on the amount of volatile leave. Second, the coating of large amount of glue, curing a long time, the penetration of the aluminum layer on the strong. It should be based on the substrate and use, after a small test to determine the reasonable process parameters, select a reasonable amount of glue.

(2) aging conditions, mainly aging temperature is too high. Control of curing time, appropriate to reduce the aging temperature of aluminum can reduce the transfer.

(3) glue mix proportion is not correct. Reducing the proportion of curing agent in a certain range can improve the aluminum transfer, the specific method is with the working adhesive, reducing the amount of curing agent, the main agent and curing agent crosslinking degree decreased, thereby reducing the film Of the brittleness, to maintain good flexibility and stretch to control the aluminum layer of the transfer.

(4) adhesive selection is not correct. Select the appropriate or special adhesive. In the composite aluminum coating, do not use too low viscosity of the adhesive, because the low viscosity of the adhesive molecular weight is small, the intermolecular force is weak, strong molecular activity easily penetrate into the aluminum inside the aluminum plating adhesion .

(5) the quality of the substrate itself is poor. Substitution of the adapted substrate.

(6) operating tension is too large, will lead to elastic deformation of the aluminum foil strain, resulting in transfer. Control tension, in the aluminum roll, the tension must be controlled. The reason is that under the effect of tension in the aluminum film will be stretched, resulting in elastic deformation. The aluminum layer is correspondingly easy to loose, the adhesion is relatively reduced.

(7) excessive solvent destruction of the General Assembly aluminum. Because the aluminized layer of aluminum foil thinner, it is inevitable there will be some pinholes, residual solvent penetration into the aluminum layer of aluminum layer damage caused by aluminum transfer.