Nowadays, printing has more and more occupied people's vision, we can not live without a variety of printing. With the advent of the Internet, electronic reading has challenged traditional paper reading, but the printing industry is still thriving. Many people don't know about the quality of printing. It's a mistake to blame the printing equipment for the problem. The characteristics of the paper are also crucial to the quality of the printed matter. The Ji'nan printing house specifically introduces the influence of paper characteristics on printed matter.
1. The influence of paper moisture content on the quality of printed matter
For fine printed matter, the requirement for registration is high, and generally the error is within 0.05mm. In multicolor printing, there are many reasons for the prohibition of overprinting, but the paper deformation caused by the change of water content in the printing process is an important factor.
The moisture content of paper refers to the percentage of water content in paper. When the moisture content of paper is too high, the bonding force between fiber, filler and adhesive will simply decrease, which will reduce the hardness and stiffness of paper, affect the paper surface strength, resulting in printing products showing deinking, delamination and other adverse conditions, but also easy to add paper plasticity, seizure deformation, the formation of print overprint ban, delay. If the moisture content of the paper is too low, it will lead to poor elasticity of the paper, brittle paper, reduced tear, easy to occur static electricity when printing. The change of paper moisture content not only leads to the expansion or shortening of paper, but also changes the size of paper due to the change of water content, and then leads to paper deformation, curling, wrinkling, lotus leaf edge and so on. Paper deformation is an important factor causing the prohibiting of multicolor printing.
(1) At room temperature, the change rate of water content caused by the change of relative humidity at high humidity is much greater than that caused by the change of relative humidity at moderate humidity, and the same is true at low humidity. From this point of view, printing is most advantageous under moderate humidity.
(2) they form a closed hysteresis loop, which is called the hysteresis phenomenon of paper wetting. In order to make the moisture content of paper uniform and common throughout the paper, the sensitivity to environmental humidity has decreased, improve the stability of paper size, generally before printing, wet processing.
Two. The influence of smoothness of paper on the quality of printed matter
The smoothness of paper is an important factor for printing suitability, which affects the overall ink handling and the clarity of the picture and text. When the ink layer thickness is slightly changed, the paper with high smoothness can still adhere to a higher and more stable ink transfer rate, and can quickly form a uniform and smooth dry ink film on the paper, with outstanding luster, rich color layers, gorgeous, lively; on the contrary, the paper with low smoothness, because of its uneven appearance, porous. Clearance, ink immersion more, ink layer gloss poor, small dots will fall into the concave part of the paper and can not print, the printing level is not clear, severe printing will form impractical, color deviation, etc., directly affect the printing effect of the printed matter, especially on the printing requirements of higher cigarette marks, should choose a high smoothness of the paper into Print production.
Three. The effect of whiteness of paper on printed matter
The whiteness of paper refers to the ability of paper to reflect fully after being illuminated, and also to the degree of brightness of paper. Generally speaking, the higher the whiteness of the paper, the smaller the chromaticity component absorbed and lost, the better the reproduction effect, the brighter the color reflected in the printed pictures, the more intense the contrast of the tone levels, and the stronger the stereo sense; otherwise, the color and tone levels reflected in the printed pictures will be dim, the less the contrast is short and the less the stereo sense. However, it is not the higher the whiteness of the paper, the better, inappropriate high whiteness because the reflected light energy is too strong, enhance the impact on the visual nerve, easy to cause visual fatigue. Any white paper is biased, not neutral. Therefore, in any case, it is necessary for the same batch of paper to have the same whiteness, color uniformity and color difference, otherwise the printed matter will have a significant color stratification, color unevenness.
Four. The influence of ink absorption function of paper on printed matter
The ink absorption function of paper is the ability of ink to soak the paper. If the paper can absorb too much ink, will lead to a significant decline in the concentration of printing color, can not achieve the desired color saturation, together with the ink layer is also short gloss, in addition, because the ink layer on the paper is short of connectors, pigment particles suspended on the paper, can not meet the maintenance, the ink film on the printing is not Solid, simple imprinting attack "pulverization" is deinking phenomenon, together with a poor color rendering effect, ink density decline, and even the occurrence of overprinting phenomenon. The paper absorbs the ink too badly, although it can get the bright color ink layer in the printing process, but it affects the ink's immersion condensation and oxidation polymerization, the ink layer adhesion is not solid, simple occurrence of reverse smudging phenomenon, in addition, the paper's weak ink absorption is not conducive to improving the printing speed, and then also affects the production efficiency. As a result, it is of great significance to accurately evaluate the ink absorption capacity of paper and to guess its impact on the quality of printing, and to control and improve the quality of printing products.
Paper, as the carrier of printed matter, plays an important role in our printing process. Jinan Printing Factory reminds us that when printing, we should choose good quality paper, many businesses in order to make a profit in printing paper jerry-built cutting, such printing is very visual impact. Pick us and ensure quality.