Self-adhesive label printing, also known as self-adhesive printing, trademark printing, is to use a certain printing method to print the label into a self-adhesive self-adhesive material. Mark it on the packaging. So, what are the ways of printing self-adhesive labels? What are the characteristics? The following small series will introduce to you.
Printing Method 1: Embossing
Use letterpress to print self-adhesive labels, the printing plate is photosensitive resin letterpress, and the printed label has the advantage of full ink color, but now the grades of letterpress printing equipment are quite different, some are still using circular flattening letterpress, some use ordinary Some of the rotary letterpress machines have adopted professional oblique-back, satellite or unit-type self-adhesive label printing machines, so they cannot be generalized during the transformation.
Professional self-adhesive printing machines mainly based on letterpress printing have the ability to print film labels, but it is necessary to contact the supplier to replace some related components, such as adding a tension control system controlled by a servo motor, adding a film surface treatment unit, high-grade Some machines can also add a precision register system. In addition, the power of the uv light source should also be adjusted appropriately.
For companies that print self-adhesive labels with a circular flat type letterpress printing machine, if printing film labels, you can replace the photosensitive resin plate with a high-elasticity flexographic plate, use water-based ink or UV ink suitable for flexographic printing, and change the properties of the ink to Adapt to substrate changes.
Printing Method 2: Offset Printing
Offset printing is the main way of printing paper self-adhesive in label printing factories in my country. Offset printing is characterized by fine pictures and texts, rich layers, suitable for large-scale printing, and the printing equipment can be used for multiple purposes, which is suitable for the characteristics of the Chinese label market. However, sheetfed offset printing is not suitable for printing films with non-absorbent surfaces, because film labels are mostly roll-to-roll printing and require volatile drying inks. Offset printing can print thicker plastic materials, such as in-mold labels and label tags, but the machine must be equipped with a UV curing device, which requires a lot of money.
Printing method three: flexo printing
At present, the quality of flexographic printing is no less than offset printing, and even has its own unique place. The advantages of this printing process are that the machine structure is simple, the cost is low, the printing quality is comparable to offset printing and gravure printing, and it has the advantage of thicker ink layer than offset printing products. Flexo printing uses water-based ink and UV ink, which does not pollute the environment.
However, due to the greater elasticity of the flexographic plate, the tone reproducibility is different from that of gravure and ordinary letterpress. The dot increase from the highlight to the midtone of flexographic printing is larger, the printing contrast is small, and the highlight level is prone to faults. When labeling, in order to make up for the layer defects, the highlight part can use FM dots, dark or middle call AM screening to improve the quality. Label printing plants without flexo presses can introduce laminated narrow-web flexographic printing presses dedicated to self-adhesive label printing, which are suitable for film label printing. Since flexographic printing machines all use circular die-cutting, the price of die-cutting rollers is high, and the production cycle is long. It is only suitable for long-running jobs, and it is not suitable for the large demand for short-running jobs of domestic self-adhesive labels. But it is an easy-to-convert label printing device that works inline with the film slitting, stitching, and sealing processes.
Printing method 4: Gravure printing
Gravure printing uses a short ink path inking system for ink supply, web printing, and a high degree of automation. It uses solvent-based inks, and the ink layer dries quickly, which is the first choice for film printing. Generally, the speed of gravure printing machine is high, and the back end of many gravure printing machines is also equipped with a cylinder die-cutting device, which can perform die-cutting and creasing, and is suitable for printing various labels. However, due to the long period of gravure plate making and the high cost of plate making, it is only suitable for mass label production.
Printing Method 5: Screen Printing
Screen printing is the most adaptable printing method for substrates. At present, many screen printing factories use low-cost screen printing equipment to contract the printing business of self-adhesive labels and film labels.