Due to the rough surface of the pulp molded articles, the printability of the pulp molded articles is obviously different from that of ordinary paper printing materials such as offset paper, coated paper, and cardboard, and the general paper mold packaging products have the appearance of the packaged articles. Matching geometry.
Its structure is diversified, convex and concave changes, and the printing format is small, it is difficult to meet the requirements of the traditional printing process. Consider flexible printing methods, such as pad printing, inkjet printing, screen printing, letterpress offset printing, etc. The concave and convex surface of the paper-type packaging product realizes multi-color fine printing.
(1) Surface printing method of paper mould packaging products
According to the printability of the paper mold material and the structural characteristics of the paper molding product, the surface printing can be done using pad printing technology. Pad printing is an indirect printing method. It uses a silicon-rubber cast hemispherical pad head to press against a copper or steel gravure layout. The graphic ink on the plate is then stenciled and transferred to the substrate to complete printing. . It can finish multi-color fine printing on uneven surface.
Pad printing For small printing products such as paper mold packaging products with small area of ​​graphic arts and varied geometric shapes, comprehensive considerations such as equipment investment, cost accounting, and ease of operation are more desirable.
(2) Surface ink-jet printing of paper mold packaging products
Paper mold packaging products in its structure changes more convex and concave, the use of inkjet printing can also complete its surface decoration printing. Inkjet printing is a non-contact, non-engraving imaging printing method. It uses a computer to store information without having to store graphic information on the printing plate. The printing head does not touch any part of the substrate and can change in operating conditions. In a wide range of situations, clear texts and patterns are reliably printed on the concave and convex surfaces of paper-type packaging products.
The principle of ink-jet printing is to spray tiny ink dots from one or more print heads through the slits onto the surface of each paper molding product located on the production line to form a text and pattern composed of dots. The printer uses a microprocessor to control the text patterns required to synchronize the speed of the sensor with the speed of the production line to ensure that each paper molding product is properly printed with graphic data. The ink is ejected by pressure or static electricity. It can be printed horizontally from bottom to top, from top to bottom, or from any angle. It is especially suitable for the surface printing of paper-type packaging products with various structural shapes.
