Tinplate for cans printing requirements
Tinplate for cans, commonly known as iron cans, iron boxes, is made of tin cans, tinplate is the surface of the iron on the tin. To play a protective role. In general, in order to packaging beautifully, and the use of printing, commonly known as printing iron cans. Usually according to its actual use is divided into mooncake cans, iron tea cans, coffee cans, biscuits cans, health care cans, beauty cans, hand-held cans, piggy bank, sealed cans, milk powder cans, wine cans, Christmas cans, gift cans, candle cans, metal drums, badges, coasters, tinplate toys, music boxes, cigarette cases, stationery, CD boxes, cigarette boxes, various types of special-shaped cans mold.
Tinplate for cans Printing requirements:
(1) Require ink with good adhesion and mechanical properties
As the tinplate print eventually to be made into canned food, toys, metal frame and chemical products barrels, cans, the need to be cut, bending and stretching process, so that printing inks for tinplate has a good adhesion and the corresponding mechanical properties.
In order to improve the ink adhesion, printing before the first need to carry out white tinplate. White is the base of all pictures, has a high lightness. After adding other high energy hue, it can improve the brightness of various colors and form the color order.
(2) Requirements for ink
Tinplate surface is silver (or yellow), metallic luster, before the printing of color text, the need to paint the surface white or white, subject to the limitations of ink coverage, monochrome machine is often required by 2 times the white, its whiteness of up to 75%. Whiteness as an important indicator of the quality of tinplate printing products, requires white ink with a good combination of primer, after several high-temperature baking not yellowing, high-temperature steaming is not Yarse.
To the tinplate coating primer, can increase the adhesion with the tinplate, dialogue ink has a good adhesion. The commonly used primer is epoxy amine base type, has the color shallow, after several times bake not yellowing, does not have the aging characteristic and the flexibility good, the impact resistance craft performance.
(3) The requirements of color ink
tinplate printing color inks, Tinplate for cans in addition to a certain degree of water resistance, but also need to have their special requirements. Because the surface of tinplate does not penetrate moisture and solvents, need to be baked and dry, so its ink should be heat-cured.
The tinting strength and durability of pigments are very high. Printing ink In addition to the general Offsctdruckereien Ink basic performance, according to the characteristics of iron and steel should also have heat resistance, ink film adhesion, impact resistance, hardness, and resistance to cooking and light characteristics.
(4) Drying process of ink
In tinplate printing production, Tinplate for cans the drying of ink is a complex physicochemical reaction process. To reasonably control the drying speed of ink, master the physicochemical mechanism of ink drying, can effectively carry out fast printing operations to ensure product quality.
Ink drying too fast will reduce the normal transmission performance of the ink, affecting the normal production; resulting in imprinting faxu, ink-color, printing plate, ink roller surface ink dry, so that the transfer of the next ink blocked, so that the printing plate dry layer outward expansion, so that the amount of desiccant excessive ink adsorption increased, blank part of the phenomenon.
and ink drying is too slow and can cause overprinter difficulties, adhesion, adhesion, etc., firmness, easy to cause the transmission process of scratches. So the ink drying speed should be appropriate, too fast too slow is unfavorable.
(5) Special structure of printing equipment
Because of the different substrate, the auxiliary mechanism of the tinplate printing press is also different from the printing press. Tinplate insoluble in water, do not absorb solvents, so printing inks need to be high-temperature baking to make the solvent volatile conjunctival curing. Tinplate for cans Therefore, the printing process equipment generally need to be equipped with a drying room. The entire tinplate printing line is generally about 50 meters in length, with a large precision.
In addition, the tinplate printing machine is the use of and dual-sheet control, the high hardness of tinplate material also determines that the printing process can not be used in the advanced continuous iron transport structure, Tinplate for cans in the push branch, the alignment and the structure of the material part is different from the printing press.