1. Ordinary letterpress printing. It is currently the most commonly used printing method, suitable for roll-to-slip printing. Due to the use of oil-based relief ink, there is a problem of drying. There are two drying methods:
1) After printing, cut the leaflets and put them dry. Occupy a large space, easy to dirty adhesion.
2) Post-printing film. The undried ink is compounded between two films. Note that after the film is coated, the label should be prevented from bleeding and die-cutting, resulting in falling of the film and quality problems.
2. Letterpress printing. It is an advanced printing method with good quality and high efficiency. Since the ink is instantaneously dry, the film can be rewinded without lamination. Suitable for roll-to-roll and roll-to-sheet printing. At present, devices for rotary printing and partial intermittent feeding are equipped with devices.
3. Solvent ink flexo printing. At present, inks made from harmful solvents such as benzene are basically not used, and solvent inks are alcohol-soluble inks. Due to the low surface tension of the solvent ink, the surface tension requirements of the film are not as strict as those of other inks, so the ink layer is strong and the printability is good. Solvent inks are commonly used in some film materials that are not suitable for printing.
4. Water-based ink flexographic printing. The water-based ink has strict requirements on the surface tension of the film, and the ink matching the film should be used when printing. Post-printing is required to protect the ink layer. In order to enhance the firmness of the ink, transparent alcoholic ink can be printed on the surface of the film first, and then water-based ink can be printed.
5. Ink flexo printing. The principle is the same as the letterpress printing, which is the most suitable printing method for printing films. The printing quality is good and the ink is bright. Small deformation, suitable for mesh color printing. Flexographic printing is currently the fastest growing printing method in developed regions in Europe and America.
Solvent ink screen printing. Traditional printing methods generally use single-sheet printing, and very few are web printing. Sheet-fed printing has low cost, good effect and strong adaptability. It is currently the main printing method for single-sheet film self-adhesive materials in China.
screen printing. It can be printed on a single sheet or on a roll. It is the latest printing method. Sheetfed printing is currently widely used in screen-like imitation metal printing, and special screen inks are used to achieve special effects. Rotary screen printers all use ink; combined printers use ink in the printing of solids and lines, and color blocks to suit high-speed production.
offset printing. The latest international technology. It can print high-quality color graphics and is suitable for long-term, high-level label production. At present, offset printing applications are not universal.
Gravure printing. Includes printing of solvent inks and inks. Gravure printing is the best quality printing method for all printing methods. With the advent of label processing machines, more and more printing houses use gravure printing machines to print labels. The gravure printing machine is suitable for printing long-lived, high-quality labels, such as beer labels, battery labels, and the like.