Plastic packaging bags are generally printed on various plastic films, and then combined with barrier layers and heat-sealing layers to form composite films, which are slit and bag-made to form packaging products. Among them, printing is the first line of production and the most important process. Printing quality is the first to measure the grade of a packaged product. Therefore, understanding and controlling the printing process and quality has become the key to flexible packaging production.
1. Gravure printing
The printing of plastic film is mainly based on the gravure printing process. The plastic film printed with gravure has the advantages of high printing quality, thick ink layer, bright color, clear and lively pattern, rich picture layer, moderate contrast, vivid image, and strong three-dimensional effect. Gravure printing requires that the registration error of each color pattern is not more than 0.3mm, and the printing plate of gravure printing has strong printing resistance and is suitable for long-version jobs. However, gravure printing also has shortcomings that cannot be ignored, such as complex pre-press plate making process, high cost, long cycle, and large pollution.
2. Flexographic printing
Flexographic printing mainly uses flexographic printing inks and quick-drying printing inks. The equipment is simple, low cost, light plate quality, low pressure during printing, low plate material and mechanical loss, low noise and fast speed during printing. The flexographic plate has a short time for plate change and high work efficiency. The flexographic plate is soft, flexible, and has good ink transfer performance. It has a wide range of printing materials. The cost of printing small batch products is lower than that of gravure printing. However, flexographic printing has higher requirements for ink and plate materials, so the printing quality is slightly inferior to the gravure process.
3. Screen printing
During printing, the ink is transferred to the substrate through the mesh of the graphic part through the squeeze of the squeegee, forming the same graphic as the original.
Screen printing products have rich ink layers, bright colors, full colors, strong hiding power, wide selection of ink varieties, strong adaptability, low pressure during printing, easy operation, simple plate-making process, low equipment investment, and low cost , Good economic efficiency, wide variety of printing materials.
Packaging promotes the overall image of commodities no less than advertising. It has many functions such as beautifying commodities, protecting commodities, and facilitating commodity circulation.
Post time: Nov-27-2020