The appearance visual effect inspection includes new items such as the inspection of the flatness and clarity of the vacuum bag. The key is to check whether the surface layer has obvious scratches and pinholes, and the seal has zero pollution. The actual appearance inspection method is as follows:
1: Inspection of metal drawing on the surface of the vacuum bag. Put the vacuum packaging bag in the middle of your hand, point it to a 40w day fluorescent lamp and gently shake it. According to the refracted light on the surface of the composite packaging bag, you can clearly see whether the surface of the vacuum packaging bag is present. Scratches or marks are often referred to as "bag-surface metal wire drawing" in the industry. Most of the metal wire drawing conditions are caused by the plastic bag making machine pulling the correct guide roller and the guide roller is not clean, so it is necessary to ensure that the guide roller is tidy. In addition, If the guide roller does not rotate, the vacuum packaging bag will cause a common failure of metal wire drawing.
2: Inspection of the flatness of the vacuum bag. Place the vacuum bag alone on a flat table. If the surface is bent, warped outward or arched inward, it indicates poor flatness, on the contrary, it indicates good flatness. The reasons for the poor flatness are generally as follows: the high temperature of making the packaging bag, which has destroyed the in-situ tensile strength of the inner layer of the composite packaging bag; the unscientific structural composition; the uneven thickness of the raw material itself, etc.
3: Inspection of the clarity of the vacuum bag. For some products, because of the large-scale no-pattern design, clarity seems to be crucial. The way to check the clarity is: extract a bag of finished products and observe the indirect light source in the room. If there are "black spots", "rings", "fog" and other conditions in the blank, it indicates that the clarity is poor, and the opposite is explained. The clarity is excellent.
