Metal box printing ink classification and printing process requirements

Metal box printing is a printing method on special printing materials. Most of its products are intermediate products, especially metal plate printing products used in the packaging field. For example, the production of metal box three-piece cans is to print the metal plate first, and then Processed into a box shape. Of course, in some cases, it is first formed into a metal box or container accessory and then printed, such as cans, partially stamped metal boxes and other products. Generally speaking, the metal box printing used in various product packaging mainly includes the following.

 ⑴Iron cans. Mainly include engine oil cans, edible oil cans, paint cans, etc. The shells of these tin cans are printed with metal, which can vividly express the name, characteristics and usage methods of the contents.

(2) Aerosol tin cans. Such as cleaning agent, rust loosening agent, insecticide, hairdressing mousse, polishing wax and other products used in aerosol cans.

  ⑶ Metal tin cans for food. Generally three-piece cans, such as canned meat, canned seafood, canned fruits or vegetables, etc. In the past, this kind of products used paper-sticking trademarks and printed iron with less color printing. At present, most of them have adopted tinplate color printing, which not only increases the added value of such products, but also reduces the probability of products being counterfeited.

(4) Beverage cans. The metal cans used for beverage packaging include both two-piece cans and three-piece cans. For example, the packaging used for carbonated beverages (such as cola, sprite, beer, etc.) is generally two-piece cans (pop cans), which are used for juice beverages (such as milk). Three-piece cans are usually packaged in dew, orange juice, watermelon juice, grape juice, etc.).

(5) Miscellaneous tin cans (boxes). Such as candy cans, biscuit boxes (cans), moon cake boxes (cans), tea boxes (cans), condiment boxes (cans), medicine boxes (cans), sanitary products boxes (Cans), gift boxes (cans), high-end cigarette boxes, etc.

(6) Bottle (can) caps. Mainly include unscrewed lids, aluminum anti-theft lids, aluminum two-piece can lids, beer bottle lids, some metal cans, glass can lids, etc.

(7) Insulation tin cans. Mainly the outer shells of thermos flasks and coffee pots. These products are exquisite and beautiful in appearance, so they put high demands on printing iron. Due to the high processing requirements of such products and the small quantity, many printing iron manufacturers are discouraged. Ten years ago, tinplate color printing on thermos flask shells was mainly produced in Japan, European countries and regions. At present, the iron printing equipment used in mainland China has been greatly improved, and the technical level is showing a rising trend.

(8) Metal boxes for electronic products. The tinplate color-printed shells of these products require higher requirements than thermal insulation tanks. In terms of pattern design, besides these characteristics of heat-preserving tin cans, it must be concise and lively. Although it seems simple with gray or red English letters on the white, the cleanliness of the printing surface is more stringent.

(9) Box-shaped products. Including stationery metal boxes, gift metal boxes, medicine metal boxes, balsam metal boxes, cooling oil metal boxes, etc. The tinplate stationery box has the characteristics of being light and handy, and the exquisite patterns are also very popular among students. The tinplate gift box is a fashionable product, and the design of the design is more exquisite. Some are simple pictures and texts, with a colorful pearly bottom surface, which is more noble and unique. The graphics and texts of the medicine metal box and the health care product box also show their characteristics, highlighting the individuality of the medicine. The balsam metal box is still dominated by old products and old pictures and texts. The cool oil box is a household-named must-have item. This kind of product is red with gold text lines, and the pictures and texts are simple and lively.

(10) Battery metal box. They are all tinplate color printing. All kinds of square and round battery shells are all tinplate printing. The graphics and text are mainly simple and clear. In the printed iron, due to the large consumption of battery products, the amount of printed iron is also considerable.

(11) Sign metal plates. Products that belong to non-packaging materials, such as clothing signs, gas stove signs, etc., including home-use writing boards, fall into this category. The sign is a window of the product, so the requirements for the quality of the printed iron are relatively high, and the pattern is relatively simple. In addition to the background color, some products only need to be marked on and off.

(12) Toy metal storage box. It is a large category of iron-printing products. Color-printed iron-skin toys have the characteristics of lightness and firmness, which are unmatched by plastics and other materials. Color-printed iron toys are suitable for braking toys, such as jumping frogs, robots, toy guns, etc. The printed patterns are mainly spot colors of cartoon animals.

Metal box printing requirements for ink

The printing method of metal printing adopts lithographic offset printing, and the structure of plate making and printing machine is basically the same as that of ordinary printing paper. Since the metal plate to be printed cannot be bent like paper and tightly attached to the impression cylinder, the metal plate can only pass horizontally between the blanket cylinder and the impression cylinder, so the arrangement and output of the three cylinders in the printing part Some are different from ordinary offset printing.

Metal box printing has a variety of coatings due to the characteristics of metal raw materials.

Before printing, the metal sheet is cleaned and then printed by offset printing. First, a layer of varnish is printed on the bottom layer, the second layer is printed with a white bottom layer, then graphics and text are printed in sequence, and finally varnish is printed. Because the metal box does not have absorption properties, it must be baked and dried after each color is printed. Therefore, the printing machine is equipped with a drying device. The purpose of baking is to speed up the drying speed of the oxide conjunctiva of the volatile ink so that it will not affect the overprinting of the next color.

The drying method can use steam, infrared, electric heating, etc., the oven is long, the printed product enters from one end, and the printed product is dried when it comes out from the other end. The temperature of the oven is between 150～2000℃, and the temperature of the bottom varnish needs to be 200℃. When registering and glazing oil, the temperature of the oven is about 150℃. The metal box is very easy to wear the printing plate, so indirect printing is adopted, and the imprint is transferred through the blanket, so that the contact form is hard, soft and hard to meet the ink transfer performance of printing.

Conclusion: Metal box printing ink has special requirements. Since the substrate is metal, it is difficult for the ink to be fixed on the metal surface. Therefore, the ink should meet the following requirements: heat resistance, after baking at 150 ℃, the color of the ink should still be very bright , The color ink is not dim, and the white color does not change to yellow; fastness, that is, strong adhesion, the printed graphics and text will not fall off when the machine is punched when the can is made; pressure water vapor resistance, food cans are disinfected and sterilized, the ink layer It can withstand the influence of water vapor without swelling; it is resistant to solvent erosion, light resistance, weather resistance, etc., and it can withstand sunlight and various climates without discoloration or slight discoloration.