Self-adhesive label printing, also called self-adhesive label printing and trademark logo printing, is a product that uses a certain type of printing method to make labels into self-adhesive self-adhesive printing and printing products. It can be peeled off and pasted on the product or outer packaging to mark it. Common technologies for self-adhesive label printing include letterpress printing, offset printing, flexo printing, gravure printing, and screen printing.

1. Letterpress printing

Use letterpress printing to print self-adhesive labels. The printing plate is a light-sensitive epoxy resin letterpress. The printed label has the advantage of light ink and roundness, but now letterpress printing Equipment levels vary greatly. Some are still using rotary embossed printing machines, some are using ordinary rotary embossing printing machines, and some have adopted professional slant-back, satellite or unit-type self-adhesive labels. Printing presses, therefore cannot be generalized when transforming and developing.

Professional self-adhesive label printing machines that mainly focus on letterpress printing have the ability to print film labels, but they need to contact the supplier to replace some related components, such as the servo motor-controlled tension control system. , Add a film surface treatment unit, and some high-end machines can also add a precise registration system. In addition, the UV light source power also needs to be adjusted appropriately.

For companies that use circular flat letterpress printing machines to print self-adhesive labels, if they print film labels, they can replace the photosensitive resin plate with a high-elastic flexographic plate and use water-based ink or UV suitable for flexographic plates. Ink, change the type of ink to adapt to changes in printing technology.

2. Offset printing

Offset printing is a method used by label printing factories to print paper self-adhesive labels. Offset printing is characterized by detailed text and pictures, rich layers, suitable for mass printing, and the printing equipment can be used for multiple purposes.

However, one-piece offset printing is not suitable for printing films that do not have a quick surface layer. Because film labels are mostly roll-to-roll printing, the ink needs to be evaporated to dry. Offset printing can print thicker plastic materials, such as in-mold labels and clothing tags, but the machine must be equipped with a UV curing device, which requires a lot of expense.

3. Flexo printing

At present, the quality of flexographic printing is not inferior to that of offset printing, and even has its own unique features. This type of printing process is characterized by simple equipment structure and low cost. The printing quality is comparable to offset printing and gravure printing, and it has the advantage of stronger ink layer than offset printing products. Flexo printing uses water-based ink and UV ink, which does not pollute the environment.

However, because the elasticity of the flexographic printing plate is very high, the tone reproducibility is different from that of gravure printing and general letterpress printing. The dot expansion from trimming to mid-tone in flexographic printing is relatively large, and the printing gap is small. Highlight levels are very prone to faults. When printing labels with fine text and graphics, in order to better fill in the shortcomings of the levels, FM dots can be used for the highlight part, and AM screening can be used for dark tones or in the middle to ensure quality.

4. Gravure printing

Gravure printing uses a short ink path ink delivery system to supply ink, web printing, and a high level of automation technology. Solvent-based ink is used and the ink layer is dry. It is fast and is the first choice for film printing. Generally, gravure printing machines have higher speeds. Many gravure printing machines are also equipped with drum die-cutting equipment at the back, which can realize die-cutting and embossing, and is suitable for printing various labels. However, because gravure printing takes a long time to make plates and is expensive, it is only suitable for mass production of labels.

5. Screen printing

Screen printing is a printing method with wide adaptability to printed materials. At present, many screen printing factories use cheap screen printing equipment to contract self-adhesive Label and film label printing business processes.

Screen-printed labels are characterized by thick light ink and strong layering. UV ink can be used to print film products.

Except for a few types of rotating screen printing equipment that can be used for roll-to-roll label printing, the vast majority of screen printing equipment is an automatic flat screen printer that can only print one product. The precision is not high and is not suitable for film label production equipment with production line supporting facilities. At the same time as the service transformation and development of post-printing production technology, we should also pay attention to the relative changes in post-printing production and processing of labels. For example, when printing self-adhesive labels, the post-printing production and processing of self-adhesive labels should be divided into single pages according to the way the label is used. Paper production and processing and roll paper production and processing.