Visual inspection of the appearance including the flatness of the composite bag, transparency checks, etc. It is mainly used to detect whether there are obvious scratches and pinholes in the composite bag, whether there is pollution at the seal, etc.. The visual inspection method is as follows:①”bag surface brushed”inspection. Place the compound bag in the center of the hand, aligning40wThe fluorescent lamp is shaken gently, and through the reflected light on the surface of the composite bag, it can be clearly found whether there are scratches or marks on the surface of the composite bag.”bag surface brushed”The wire drawing phenomenon is mostly caused by the unclean guide roller of the bag making machine, so it is necessary to ensure that the guide roller is clean. In addition, the non-rotation of the guide roller will also cause the drawing failure of the composite bag.② Inspection of the flatness of the composite bag. Put the composite bag on a flat table. If the surface of the composite bag is curved, warped outward or inward, it means that the flatness of the composite bag is poor. Otherwise, it means that the flatness is good, and the reasons for the poor flatness are generally as follows. A few points: the bag making temperature is too high to destroy the stress stiffness of the inner layer of the composite bag; the structural composition is unreasonable; the thickness of the material itself is uneven.③ Transparency inspection. Because some products have no pattern in a large area, transparency is particularly important. The inspection method for transparency is: take a finished bag and observe it through an indoor indirect light source.”pitted”,”ring”,”foggy”and other phenomena, it means that the transparency is poor, otherwise it means that the transparency is good.
- The difference between biodegradable bags and ordinary PLA stic bags January 30, 2023