Reasons for Delamination of PET Metallized Film

The problem of PET metallized film delamination involves multiple complex factors, which are intertwined and jointly lead to the occurrence of delamination.

1. Challenges of polyurethane adhesives: Polyurethane adhesives are known for their strong adhesion, but in combination with PET metallized films, this adhesion sometimes exceeds the adhesion between the metallized layer and the PET substrate. To further complicate matters, the ethyl acetate component in polyurethane glue may weaken the connection between the PET surface and the metallization layer, making them easy to separate.

2. Fragility of the metallization layer: Due to the thin thickness of the vacuum metallization layer, it is particularly sensitive to the external environment. Once it is corroded by moisture or adhesive solvents, the metallization layer is prone to problems, such as oxidation, black spots, or even complete disappearance.

3. Challenges of ink and surface treatment: During the printing process, the type of ink and the degree of surface treatment have an important impact on the stability of PET metallized films. For example, some inks may be incompatible with metallized layers, causing delamination. At the same time, if the surface treatment is improper, such as corona treatment or improper primer treatment, it may also affect the adhesion of the ink and the stability of the metallized layer.

4. Matching problem between substrate and adhesive: The cleanliness and integrity of the substrate surface are crucial to the stability of the metallized layer. Any oil, foreign matter or slight heavy skin may affect the adhesion of the metallization layer. In addition, the selection and use of adhesives also need to match the substrate and metallized layer, otherwise it may cause delamination of the PET metallized film.

5. Complexity of the composite process: Multiple links in the composite process may affect the stability of the metallization layer. For example, the viscosity of the adhesive, the softness of the adhesive film, the amount of glue applied, the tension control and the curing speed all need to be precisely controlled, otherwise it may lead to migration and delamination of the metallized layer.

6. Influence of hot and humid environment: Under hot and humid conditions, the physical properties of the PET body film will change, such as an increase in the glass transition temperature. This change may affect the stability of the metallization layer, especially in environments with higher humidity, where the metallization layer is more susceptible to corrosion and peeling.

To sum up, the problem of PET metallized film delamination is a complex issue involving many factors. In order to solve this problem, we need to start from many aspects such as material selection, process control, environmental control, etc., and comprehensively consider various factors to find the best solution.