Corrugated cardboard is made into corrugated boxes by die-cutting, creasing, nailing or gluing boxes. Corrugated boxes are the most widely used packaging products, and their usage has always been the first among various packaging products. Including calcium plastic corrugated boxes. For more than half a century, corrugated boxes have gradually replaced wooden boxes and other transportation packaging containers with their superior performance and good processing performance, becoming the main force of transportation packaging. In addition to protecting goods and facilitating storage and transportation, it also plays a role in beautifying and promoting goods. Corrugated boxes are green and environmentally friendly products, which are good for environmental protection and convenient for loading, unloading and transportation. In 1856, the British brothers Edward Healy and Edward Allen invented corrugated paper pressed into corrugated corrugated sheets as the lining of a hat to breathe and absorb sweat. In 1871, American Albert Jones invented single-sided corrugated cardboard for packaging glass lampshades and similar fragile items, and obtained the first patent in the United States. By the end of the 19th century, the United States began to study the use of corrugated cardboard to make packaging and shipping boxes. In 1920, double corrugated cardboard was introduced, and its uses rapidly expanded. During World War I, corrugated boxes accounted for only 20% of shipping packaging. But during World War II, corrugated boxes accounted for 80% of transportation packaging. Corrugated boxes have now become the most widely used packaging containers in modern commerce and trade, and are also one of the most important forms of packaging used in countries around the world today. The printing methods in the printing and packaging industry mainly include: offset offset printing (color printing with ink) and letterpress printing (ink printing on cartons). Among them, water-based printing on cartons has higher strength, lower cost, and higher production efficiency (faster delivery) than color printing. The overall printing effect is close to color printing, and it is widely used in the transportation and packaging of products. The main production processes of corrugated cartons include the corrugated cardboard automatic production line, printing process, post-processing and forming processes; the printing work has basically realized one-time automated printing, slotting, die-cutting, carton gluing and packaging. 2. Principle of water-based printing Water-based printing belongs to additive color printing. The color original is electronically separated and plated into a reverse image, and then printed through a printing press. The ink is transferred from the anilox roller of the printing press to the printing plate, and then the ink is transferred from the printing plate to the corrugated cardboard. Obtain the front image through color registration and color overlay, realize the copy of the original sample box, and reproduce the quality of the original. Principle of four primary colors: red, yellow, blue, and black (strictly speaking, there are three primary colors: red, yellow, and blue) secondary colors: the addition of two primary colors: red + yellow = orange (orange-red, orange-yellow); red + blue = purple ( cherry red, eggplant purple); blue + yellow = green (dark green, light green). 3. Prepress technology (traditional plate making) The color original is processed into a single color through electronic color separation and then produced as a film (negative film); back exposure: the back of the plate is exposed with ultraviolet rays to form the base of the printing plate; main exposure :Tear off the protective film on the front of the plate, put the negative image on it, and cover it with the vacuum film. After the vacuum is drawn, use ultraviolet rays for main exposure to transfer the contents of the negative image to the printing plate; wash the plate: use medicine in the plate washing machine Water is used to wash the plate and wash away the unexposed resin on the printing plate to form a concave and convex printing plate. Drying: detackification: ultraviolet light source irradiation; post-exposure: hardness adjustment. 4. Printing materials - base paper classification Corrugated base paper (corrugating medium) national standards are divided into four types: A grade, B grade, C grade and D grade. Class D corrugated paper has been basically eliminated by the market, and few manufacturers purchase and use it. Linerboard kraft paper (American card, Russian card). Features: long fiber, heavy sizing, high physical strength, rough cardboard; pure wood pulp or a small amount of OCC. Abbreviation: imported kraft card. Imitation kraft card paper. Features: 15-25% wood pulp is hung on the surface, and the rest is OCC; the fiber is shorter and the strength is worse than that of ox cardboard. The paper surface is smooth, with different degrees of sizing (water absorption ranging from 30-55g/m2), and surface dyeing. Abbreviation: Domestic kraft paper. White kraft paper base, surface bleached wood pulp, the rest is natural or dyed wood pulp (Russian white, Swedish white cardboard, Finnish white cardboard); white board paper (surface bleached wood pulp, the rest. It is deinked or non-deinked waste paper); coated white board paper (white on white, gray on white, ---). Recycled paper is all composed of OCC, but it is different from corrugated paper and has an AOC surface of 11# or above. after dyeing). The market is generally called C-grade container paper, and some are called T paper. Basic properties of carton base paper. Physical indicators: quantitative, moisture, tightness, bursting strength (bursting index), ring pressure strength (ring pressure index), positive/reverse water absorption, folding endurance. Appearance indicators: smoothness, color difference, whiteness. Specific base paper standards: GB13023 (corrugated paper national standard), GB13024 (container board paper national standard). Related projects refer to the latest industry trends or standards. Basic production process of papermaking Traditional papermaking process: Raw materials: wood or grass fiber. Modern papermaking process flow: raw materials: commercial wood pulp, waste paper.