What is uv ink offset printing?

author: Uvink

2022-12-22

What is uv ink offset printing?Offset printing can be divided into sheet fed offset printing and web

paper rotary offset printing according to the state of the substrate. Sheet fed offset printing

is suitable for paper, cardboard, plastic sheet and metal foil printing; Rotary offset printing is

fast, suitable for large quantities of books and periodicals, newspapers, business forms and

self-adhesive printing. In offset printing using UV ink, mainly consider the following aspects:

non absorbent printing materials ink curing; Ink emulsion may hinder the adhesion of ink and

substrate; The rotary printing machine is fast, and the curing speed of the ink is required to match

the printing speed. Especially for the self-adhesive printing and the securities printing with special

ink, the UV ink printing effect is better than the resin offset printing ink.

What is uv ink offset printing?Offset printing is mostly used for fine product printing.

UV curing can reduce the loss of small dots and improve the ink transfer rate of overprint.

When selecting ink raw materials,we should comprehensively consider the influence of

each component on UV ink to ensure the best printing effect. Since the offset ink film is

generally 2-3 μ m. Although it is conducive to light curing,the ink film is thin, and the

hiding power of the pigment on the substrate will be affected to some extent,so the pigment

content in the formula should be generally increased; However, with the increase of pigment

content, the transparency of the ink film will be reduced, which is not conducive to UV curing;

Moreover, the ink film itself is thin. If the wettability of the pigment is poor, the pigment and

filler are easily exposed to the surface of the ink film, affecting the gloss of the ink film.

Therefore, the pigment with good dispersion should be selected. The following points should

also be noted when using UV offset printing.

What is uv ink offset printing?Different inks should be selected for different substrates,

and the light transmittance,curing rate, covering ability of the ink and the glossiness of

the printed surface should be comprehensively considered.In color printing, the ability of

various pigments to absorb UV photons is different, and the transmissivity is M, Y, C, BK from

high to low, so the curing degree of various inks is also different. The transmissivity directly

affects the excitation energy of photons to the photoinitiator. Therefore, the printing color

sequence should be arranged as BK, C, Y, M, so that the ink with poor transmissivity can

absorb photons as much as possible to enhance its curing effect.The use of alcohol fountain

system can reduce the surface tension of the ink and promote the curing effect.In addition,

during the printing process, the fountain solution can be used to strengthen the oil repellent area

(blank part) of the printing plate, so as to ensure that the oil repellent area is full of ink and

the water repellent area is free of ink.Improving the ink formula and adding corresponding

additives can increase the hydrophobicity of the ink,but too strong hydrophobicity will lead to

image edge ink shrinkage, loss of fine layers, unclear dot boundary,etc., which will affect

the print quality.UV printing has high requirements on the surface strength of the paper,

and the surface strength is not enough,which is easy to cause galling fault. When printing with

gold and silver paperboard, because the surface of such paper is smooth and has little affinity

for ink, it is easy to pull off the first color ink when the second color is overprinted. Therefore,

in UV printing, the paper with high surface tension should be selected, the color sequence should

be reasonably arranged, and the relevant process parameters in the printing process should be

adjusted to avoid and reduce the above phenomena.