1. Appearance: The surface of the metallized thermal lamination film is flat and smooth without wrinkles or only small amount of live pleats, has no obvious unevenness, impurities and stiff spots, no plaques, bubbles, leaking holes, etc.
2. Thickness: The thickness of the metallized thermal lamination film is uniform, the deviation of the horizontal and vertical directions should be small, and the deviation distribution is relatively uniform. And there is no obvious rib on the reel, otherwise it will be easy to wrinkle when compounding.
3. The thickness of the metallized layer: Metallized layer’s thickness is directly related to the barrier property of the metallized thermal film. As the thickness of the metallized layer increases, the transmittance of oxygen, water vapor, light, etc. is gradually reduced, and correspondingly improve its barrier properties. Therefore, the metallized layer’s thickness should meet the standard requirements, and the surface should be uniform, otherwise the expected barrier effect will be destroyed.
4. The metallized layer has strong adhesion and good firmness with lamination film, otherwise the dealumination will occur between them, which would causing quality problems. The high-quality vacuum metallized thermal lamination film is pre-coated with a certain amount of primer on the metallized surface to improve the adhesion between the metallized layer and the lamination film, thereby ensuring the metallized layer is firm and does not easily fall off. Besides, in order to prevent the aluminized layer from wear, usually cover a two-component polyurethane adhesive on the surface of metallized layer.