UV imitation metal etching ink screen printing points

UV imitation metal etching printing, also known as matte or sand surface printing, is printed on a substrate with a metallic mirror gloss (such as gold, silver cardboard) after a layer of uneven translucent ink, after ultraviolet (UV) Curing produces an effect similar to that of a shiny metal surface that has been etched or sanded.

Imitation metal etching ink printing products have obvious etching effect, full ink film, strong three-dimensional effect, and make the packaging products show high grade, has been widely used in cigarette packaging, wine labels, cosmetics, health care products and packaging color printing industry. Can also be used for greeting cards, calendars, brand names, tags, advertising, for use. Can also be used for greeting cards, calendars, brand names, logos, advertising, art and other printing; UV imitation erosion remember screen printing ink can also produce suede and matt effect, can make prints soft, dignified, elegant, luxurious, to general The ink is difficult to achieve, for which reason it has been rapidly promoted and applied.

First, UV curing ink

The ink of this ink is short and thick, in which the diameter of the additive particles is about 15 to 30 μm. After printing, due to the rough and uneven film surface of the ink, the diffuse reflection is reflected in the light and the film surface is dark. In the non-membrane area with metallic luster, under the illumination, the retroreflection is a positive reflection and the gloss is strong, so the area with the film surface is dark and concave, and the area without the film surface is bright and convex. The effect of the two is the opposite. In order to reflect the intrinsic gloss of the substrate, the ink should be transparent and the hiding power should not be used. UV imitation metal etching ink is generally a mixture of photosensitive resin and other materials into a light-colored transparent paste; can also be made into color etching ink color. Its composition is as follows.

UV etching ink: main agent (silicone 15 ~ 30μm); binder (photocuring resin or prepolymer, crosslinker, photosensitizer, polymerization inhibitor).

Second, UV imitation metal etching ink screen printing points

1. Platemaking operation quality control

(1) Screen mesh number and thickness of photosensitive film

The etching ink has a certain degree of roughness. If a mesh with a high mesh number is selected, since the mesh is small, the ink does not easily pass or pass through during printing, so that the ink is uneven and a white phenomenon occurs, resulting in a poor etching effect. If you use a low mesh screen, because the mesh is too large, the amount of ink is too much, resulting in paste plate, and also affect the printing effect.

· Matte rough lines: screen 100 ~ 180 mesh; Photoresist film thickness of 10μm or less.

· Scrub mid grain (or ice flower in flower): Screen 150 ~ 250 mesh; Sensitive film thickness 12 ~ 14μm.

· Scrubbing fine text (or ice floret): Screen 200 to 300 mesh; Sensitive film thickness 14~16μm.

(2) As the imitation metal etching ink has a certain degree of roughness, the aluminum alloy frame and the screen printing machine are most used for printing to prevent the pattern from overprinting so that the pattern overprinting is difficult.

(3) Stretching the net is to use a diagonal stretch when stretching the net, minimizing jaggies and improving plate-making accuracy.

(4) Determination of tension

The size of the tension is directly related to the flatness and print quality of the squeegee-coated photosensitive film. The tension is too large, the screen becomes brittle, the reaction force on the squeegee during printing is large, and the strong screen plate is easy to tear; the tension is too small, the screen is soft, the resilience cannot be generated on the squeegee when printing, and the nap points or India outlets. Only moderate tension can ensure the dimensional accuracy of printing and printing, make overprinting accurate, and the resilience of the screen is good, and the dots are clear and resistant to printing. Under normal circumstances, it is not easy to break.

This is because once the UV lamp has reached the end of its useful life, its spectral curve will be changed, and the emitted UV rays have not met the UV ink curing requirements. Therefore, we should correctly record the use of UV lamps and replace the UV lamps that have reached the end of life.

2. Film materials can be divided into two types according to the different printing suitability: one type is required to be printed after corona treatment; the other type has already been processed with a layer that can be printed. For label printing companies, the choice of what kind of film material to buy should be based on the capabilities of the printing equipment (such as the presence of a corona treatment device). If the printing machine has a corona treatment device, you can buy the first type of film material. Before the printing, the tension of the surface of the film material shall be measured. If the tension is less than 42mN/m, the material must be corona treated before printing. This ensures that the UV ink has good adhesion to the film surface. . If the purchased film material has a coating layer that can be printed on the surface, the label printing company should consult the material supplier which brand of ink should be used because different coating formulas are suitable for different brands of ink. Only when the coating layer and the UV ink are matched can the ink adhesion problem be solved.

To sum up the above analysis, in the process of printing and processing, if you encounter the problem of poor adhesion of the film material and the UV ink used, we should correctly analyze the reasons before we can find the right solution.