- Flexo Label Printing Machine is for Self-adhesive paper is relatively thick, generally as thick as two sheets of 150g/m2 coated paper. It is composed of two layers: coated paper, aluminum foil, colored polyester film printing layer and wax paper layer.
- The paper used for self-adhesive printing is generally high-grade coated paper, gold card, silver cardboard, and colored polyester film. The surface of the paper is smooth and clean.
- The self-adhesive paper has low ink absorption. It is composed of base paper and top paper. It is easy to separate and affect the printing plate. The printing speed should be slower.
- When printing a large area of images on a full page, it is easy to get dirty on the back.
Self-adhesive label printing, also called self-adhesive printing and trademark printing, uses a certain printing method to print labels into self-adhesive self-adhesive materials. The printed products can be peeled off and pasted on goods or products. Mark it on the packaging. So, what are the methods of self-adhesive label printing? What are the characteristics? The editor below will introduce it to you.
Printing method one: embossed printing
Self-adhesive labels are printed using letterpress printing. The printing plate is a photosensitive resin letterpress plate. The printed labels have the advantage of full ink color. However, the grades of letterpress printing equipment vary greatly. Some are still using circular flattening letterpress printing machines, and some are using ordinary letterpress printing machines. Some rotary letterpress machines have adopted professional inclined-back, satellite or unit-type self-adhesive label printing machines, so they cannot be generalized during the transformation.
Professional self-adhesive 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 adding a tension control system controlled by a servo motor, adding a film surface treatment unit, and high-end Some machines can also add precision registration systems. In addition, the UV light source power must also be adjusted appropriately.
For enterprises 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 highly elastic flexographic plate, use water-based inks or UV inks suitable for flexographic plates, and change the properties of the ink. Adapt to substrate changes.
Printing method two: offset printing
Offset printing is the main way for label printing factories in my country to print paper self-adhesives. Offset printing is characterized by fine graphics and rich layers, which is suitable for mass printing. The printing equipment can be used for multiple purposes, which is suitable for the characteristics of the Chinese label market. However, sheet-fed offset printing is not suitable for printing films with no absorbent surface, because film labels are mostly roll-to-roll printing and require volatile drying ink. Offset printing can print thicker plastic materials, such as in-mold labels and labels and tags, but the machine must be equipped with a UV curing device, which requires a considerable expense.
Printing method three: flexo printing
At present, the quality of flexographic printing is no less than that of offset printing, and even has its own unique features. The advantages of this printing process are simple machine structure and low cost. The printing quality is comparable to offset printing and gravure printing, and 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 dots from highlights to mid-tones in flexographic printing are larger, the printing contrast is small, and the highlight level is prone to faults. When printing fine graphics and text, When labeling, in order to make up for the layer defects, FM dots can be used in the highlights, and AM screening can be used in the dark or middle to improve the quality. Label printing plants that do not have a flexo printing machine can introduce a laminated narrow-width flexographic printing machine dedicated to self-adhesive label printing. This printing machine is suitable for film label printing. Since flexographic printing machines all use circular die-cutting, the die-cutting roller is expensive and the production cycle is long. It is only suitable for long-run jobs and is not suitable for the large demand for short-run jobs on domestic self-adhesive labels. But it is an easy-to-transform label printing equipment that can work online with the film slitting, sewing, and sealing processes.
Printing method four: gravure printing
Gravure printing uses a short ink path ink supply system to supply ink. It is web-fed printing and has a high degree of automation. It uses solvent-based ink and the ink layer dries quickly. It is the first choice for film printing. Generally, gravure printing machines have higher speeds. Many gravure printing machines are also equipped with a roller die-cutting device at the back end, which can perform die-cutting and creasing, and is suitable for printing various labels. However, due to the long plate-making cycle and expensive plate-making costs, gravure is only suitable for large-volume label production.
Printing method five: screen printing
Screen printing is the printing method with the widest adaptability to substrates. Currently, many screen printing factories use low-cost screen printing equipment to undertake the printing business of self-adhesive labels and film labels.
