Introduction
In the third set of RMB, 1960 edition "Red One" and all banknotes, the front side is made of gravure printing. The rest of the 1, 2, 5 corner banknotes started with a front gravure, and the back is printed. Later, as the economy developed, the purchasing power of 1, 2, 5 corner banknotes is getting lower and lower, no one goes. Therefore, in order to reduce printing costs, the printing mill has also changed their pioneering to a lower cost. Early concave corner coupons have fewer lives, and the price is certainly more expensive than glue.
distinguishes "gravure" and "glue plate" to see the color and three-dimensional feelings of its pattern. If you take these two banknotes, it is very obvious, it is easy to judge. In addition, for beginners, it is also possible to adopt the following two methods: the first is "touch". The six words of the "People's Bank of China" on the positive of the gravure of the renminbi are very obvious. As long as you use your fingers, you can clearly feel that each word is raised. The second is "look at the edge". The gravure printing text and pattern, the edge of the line will have a small "burr" caused by ink diffusion, and it can be seen with a magnifying glass. The line edge of the printing plate print is smooth.
Principle and Process
Basic Principle
Oil Water is unsolicited;
The principle of selective adsorption of the printing plate;
The principle of coloring of outlets;
Indirect printing principle.
Selection of stack or trapping
If the set is not allowed, it is easy to gently affect the beauty, and the stack is easily caused by the ink layer too thick, so single The color filter is tended to use overprint, multi-chromorne moisture moisture tend to use traps;
Wet pressure stack must take into account the properties of the ink, the printed ink is viscosited, and adhesive must be Big than the post-printing ink, otherwise the post-printing ink will appear inverter printing. The post-printing ink must also have a higher transparency;
When printing gold ink, silver ink, ink, ink, ink, silver ink, is printed on white paper. The color obtained on the other base color is more thick, pure;
When black, if there is only a large field image with a large area, the black version is increased in the white version of the black version. Paper printing is more thick than the ink color obtained in other field base colors. However, the small port is generally used in printing.
Row in front of the previously trapped version to ensure that the rear ink layer covers, the trap is usually increased by 0.03 to 0.05 mm based on its equipment. If the registration accuracy is 0.15mm, the trapping portion is generally 0.18 ~ 0.20mm.
Four-color printing
When using a four-color printing process, if there is a large area of black field, because the ink solid-ground density does not exceed 1.8, the large-scale black ground is printed in such a density. It will lack thick visual effects, and the common method is a cyan that overprints about 40% in a large area black.
Angle Select
network cable for four angles in selection, 15 °, 45 °, 75 °, 90 °.
four-color printing, the main tone is generally 45 °, the yellow version is weak, select 90 °;
three-color stack, usually 30 °, 60 ° and 90 ° Angle;
two-color overlay, usually 45 ° and 90 °;
spot color printing, monochrome hierarchy printing or monochrome hierarchy stacking ground version, 45 ° The angle is usually beautiful;
45 ° network cable visual effect is best, generally used to express the character of the character, mostly for the red;
Top and black version The skeleton constitutes an entire picture, typically 15 °, 75 °.
spot color printing
A product simultaneously using four-color printing and spot color printing: The four-color printing section makes the picture correctly by controlling the field density, the bottom color is appropriately increased Available in a uniform visual effect of a color color.
If the electronic file or film provided by the customer is 2 ~ 3 spotted outside of CMYK, it adds 2 to 3 mesh, and one of the spotted inks is small, and it is easy to match with CMYK. Lose this spot. If the original of the customer is only the CMYK quad color, it is difficult to control in actual printing, such as blue and product red stacked into purple, if the green ink is large, if the product is red ink is biased, At this time, you may wish to change it here to a spotted purple version, although there is a piece of version, but the printing preparation time is shortened, the printing speed is improved, and the color phase control is stable.
Anhydrous printing
Yangmatu water plastic printing principle: is made of an aluminum version of the base, the underlying, a photosensitive resin layer, a silica gel layer, and a cover film. After the exposure, the silica gel layer of the plate (blank portion) of the plate is reactive, and the optical crosslinking is performed; the silica gel layer of the unveiled light portion (partial portion) is removed under the action of the developing fluid, exposed The following photosensitive resin layer. Since the photosensitive resin layer is ink, the silica gel layer of the unfamed portion is an ink, so that selective adsorption of the ink is completed.
Water offset printing on the environment is demanding: the temperature of the printing workshop is 23 to 25 ° C, the temperature is low, the ink will solidify; the temperature is high, a paste fault will occur. In addition, there is more difficult to decontaminate after dry water-free printing plates.
Gold and silver ink print
Tetra color offset printing is used in the use of hard packing, and the toner is short, and the printing ink is placed in front of the gold and silver ink. Digital ink;
Using monochrome offset "wet pressure dry" more advantageous: dry dry, strong print gloss, good visual effect, etc. Neutral or soft lining can be used, using neutral lining, with domestic rubber cloth, adding the law's liner cloth or jam (hardness to be good), and the pressure is slightly increased. However, the printing of semi-finished products can not be allowed, otherwise it is easy to generate crystallization phenomena, resulting in the follow-up color ink, not on the ink,
The annihole can not use red medicine water to avoid oxidation, can be used "Lite" powder Preferably, it is best to use alcohol (
Printing speed on printing pressure
To make the printing plate with ink graphic to clearly Transfer to the surface of the substrate. There must be enough printing pressure. However, the applied printing pressure is not too large, and excessive printing pressure will continue to deform, blot and become thick, outlet, paste, influence the clarity of the graphic, and will exacerbate the wear of the plate The printing plate is lowered. When the printing pressure is insufficient, there is no sufficiently reliable contact between the printing plate and the rubber cloth, and the blot will be shallow and affect the clarity of the graphic.
Printing color sequences
Usually in the case of wet moisture, the first-printed ink is dominant, such as the printed blue, printing, printing, printing ; First printing, red, blue, overlapping, printing will be red. In the case of wet pressure, it is the advantage of the post-printing ink color. From the perspective of optical perspectives, the Wet Wet Wet Pressure Wet is used to use a CMYK color order.
Under normal circumstances, for the warm-colored transfer product mainly painted, the color sequence should be black, green, red, yellow;
is cold in landscape, snow The color is mainly print, the printing color should be black, mine red, blue, yellow;
two-color machine printing color is green + magenta, black + yellow, monochromatic machine printing color It is cyan, bright red, yellow, black or black, green, bright red, yellow (generally black version for the skeleton version, black in front of the front);
In order to facilitate stack, it should be ink The thickness is arranged in a small to large sequential color, such as black ink 0.8 um-graphite 0.9 um- 品 红 1.0 um-yellow ink 1.1um;
According to the ink viscosity Printing color sequence, such as black ink 1188pa.s-blue ink 488Pa.s- 黄红 477pa.s-yellow ink 147Pa.s, if the ink viscosity does not meet the arrangement requirements, the viscosity of the ink is pre-regulated in advance;
The ink that covers a small coverage should be printed, dark ink should be printed (due to its high viscosity, large coverage, avoiding the back of the bond);
UV ink printing, The degree of absorption of the UV photons is different, causing the curing speed, so the color sequence should be black-cyan-yellow-magenta is most suitable.
Precautions
a. Color block stacking color To avoid the use of a percentage of too small balance, such as the flat network point of 20% or less. Because the color block consisting of small outlets is easy to have a small particle on the glass, the glass is bonded to the small particles due to the sufficient particles, and it is easy to be too large, the rubber cloth is easy to print when printing. Dirty or plate wear is caused. The above two reasons can cause unevenness of the color block. As for 5% of the outlets, ordinary officers are difficult to restore, and should be avoided.
b. At the same time, the color block stacking color should try to avoid the use of too large balances, such as more than 80% flat network points. Because the color block consisting of the big network is slightly insufficient or rubber-plated in the printing. As for more than 95% of the outlets should be avoided.
c. To avoid excessive colors, the colors of the colored number, which is easy to cause the back surface to be too thick because the ink layer is too thick.
d. When using a spot color printing process, try not to use a color block that needs to be deployed by excessive basic color ink. Too many ink hybrids increase the difficulty of the ink, which increases both the ink time, and it is difficult to adjust the color of the similar color phase.
e. When printing a large area of a color, you should try to avoid re-printing the fine white text and lines using this color. Because the printing large area is a thickness that is inclined to increase the thickness of the ink layer, the ink layer is easy to spread, but it will cause a small anti-white text and line paste.
f. For text, in the middle of the field, it is recommended to recommend the customer to choose the black body.
g. When printing full version, you can use the printing plate left after the previous print, stop the water supply without specializing. However, due to the adsorption capacity of the photosensitive glue and blank portion of the photosensitive glue to the ink, the color of the color (such as dark blue) of the photoreceptor (such as dark blue) of the photosensitive glue of the ink is still slightly different. Plate.