The method of producing high-grade plastic flexible packaging composite packaging materials during compounding of plastic packaging bags is currently the most widely used processing method with the largest output and the highest product quality. Considering that it includes packaging materials and specifications, and involves printing ink, glue, machinery and equipment, monsoon climate and many other phenomena, these phenomena will appear from time to time! Causes: 1. The adhesive cloth is evenly distributed and there are gravure marks; 2. The amount of glue applied is too much; 3. The wettability of the surface layer of the substrate is poor; 4. There are residues on the guide roller of the transfer film; 6. The winding tension is high, and the film becomes wrinkled; 7. The ambient humidity is high or water is trapped during processing, and there is undischarged CO2 between layers, resulting in whitening. Solution: 1. Adjust the viscosity, concentration value and scraper angle of the material liquid, and change the gravure roll; 2. Re-adjust the coating amount or change the Austrian roll; 3. Increase the temperature of the composite roll; 4. Clear the clean guide roll; 5. Fast Clean or grind the scraper; 6. Adjust the winding tension and speed; 7. Increase the drying temperature and reduce the ambient humidity. The above is all about the “subjective reasons and remedies for the poor appearance of packaging bags”.