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 cut and bagged to form packaging products. Among them, printing is the first line of production and the most important process. To measure the grade of a packaging product, printing quality is the first. Therefore, understanding and controlling the printing process and quality has become the key to flexible packaging production.
There are three commonly used printing processes in the production process of plastic bags:
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 bright pattern, rich picture layer, moderate contrast, vivid image and strong three-dimensional sense. 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 primarily utilizes flexographic and fast-drying letterpress inks. The equipment is simple, the cost is low, the plate material is light in weight, the printing pressure is small, the plate material and mechanical loss are small, the printing noise is small, and the speed is fast. The flexo plate has a short plate change time and high work efficiency. The flexo plate is soft, elastic, and has good ink transfer performance. It has a wide range of printing materials, and the cost of printing small batches of products is lower than that of gravure printing. However, flexographic printing has higher requirements on ink and plate materials, so the printing quality is slightly inferior to that of gravure process.
3. Screen printing
During printing, through the extrusion of the scraper, the ink is transferred to the substrate through the mesh of the graphic part to form the same graphic as the original. Screen printing products have rich ink layers, bright colors, full colors, strong covering power, wide selection of ink varieties, strong adaptability, low pressure during printing, easy operation, simple plate making process, and low equipment investment, so the cost is low , Good economic benefits, wide variety of printing materials.
Post time: May-07-2022