We referred to as UV printing (UV offset printing) offset printing according to the state of substrates can be divided into sheet-fed offset printing and drum rotary offset printing paper, sheet-fed offset printing is suitable for paper, cardboard, plastic and metal foil printing; Rotary offset printing speed faster, suitable for large quantities of books and periodicals, newspaper, business forms, stickers printing, etc. Using UV ink in offset printing, mainly consider the following several aspects: the absorbent material printing ink curing; Ink emulsification may hinder inks and adhesion of substrates; Rotary press speed, require ink curing speed match the printing speed, especially the securities of stickers printing ink and the use of special printing, UV printing ink printing effect is better than the offset printing ink resin type.
More than offset printing fine products used for printing, UV curing can reduce the loss of small branches, increase matching color overprint of ink transfer rate. When choosing a printing ink raw materials, to comprehensively consider the effect of each component of UV ink, in order to ensure the best printing effect. Due to offset printing ink film is commonly 2 ~ 3 microns, while the light curing, but thin ink film, paint for the covering power of the printing will be affected by certain effect, so generally to improve the formulation of the pigment content; Increased pigment content, ink film pervious to light performance decreases, go against the UV curing; Thinner and ink film itself, if the poor wettability of pigments, pigments, fillers easily exposed to ink membrane surface, affect the ink film gloss, so want to choose good pigment dispersion. Using UV offset printing also should pay attention to the following points.
(1) different substrates should choose different ink, to comprehensively consider ink pervious to light quality, curing rate, ink on the surface of the cover and the print gloss, etc.
(2) in color printing, all kinds of pigment's capacity to absorb UV photons is different, its transmittance from high to low is M, Y, C, BK, so all kinds of printing ink curing degree is also different. Transmittance directly affect the excitation energy of the photon light initiator, so appropriate to row for BK color series, C, Y, M, the transmission of light poor ink absorption of photons as much as possible, enhance its curing effect.
(3) the use of alcohol education version system can reduce the surface tension of the ink, promote the solidification, and in the process of printing, the education version available liquid for plate oil area (blank) for strengthening processing, to ensure that the oil wet area full ink, hydrophilic area is not addressed.
Improve ink formulation and add the corresponding additives can increase the hydrophobicity of ink, but too much will lead to image edge ink hydrophobicity contraction, subtle level loss, outlet boundary is not clear and so on, affect the quality of printing quality. In this paper, released by the dongguan printing www.lxpack.com finishing.
(4) the dongguan UV printing on paper surface strength is higher, surface strength is not prone to failure, hair of gold and silver cardboard printing, because this kind of paper surface is smooth, less affinity on the ink, the second color dieyin the first color is easy to pull off. So in the UV printing, should choose larger paper, surface tension and reasonable arrangement of color sequence, adjust the printing process in the related process parameters, in order to avoid and reduce the occurrence of the above phenomenon.
Contact: Robin Sun
Add: 7/F, Block 5, HaiTangYuan, XiaoBian St, Changan Town, Dongguan, GuangDong,523850 China