First, the structure and characteristics of corrugated board (a) the structure of corrugated board Corrugated board is usually at least from the surface cardboard (paper and paper), a layer of middle corrugated paper, adhesive bonding, as shown 3-76 shows.
(2) The characteristics and types of Wadi's plates are juxtaposed by corrugations, and the triangular structures formed by mutual support are both strong and resilient and can withstand a certain amount of pressure. Corrugated corrugations have different shapes and the corrugated board has different compressive strengths.
Corrugated shapes can be divided into U-shaped, V-shaped and UV-shaped three. As shown in Figure 3-77.
U-faced corrugated arc has a large radius, good elasticity, excellent cushioning, and easy adhesion. However, the amount of paper and adhesive is large, and the flat-pressing strength is low, and Advanced Flexo Printer can only restore within the elastic limit. When excessive pressure is applied, Flexo Printer Slotter Machine cannot be restored to its original condition.
The V-shaped corrugated arc has a small radius, good strength, and strong pressure resistance. However, if Flexo Printer Slotter exceeds the limit, it quickly breaks and loses its ability to recover. Therefore, the cushioning ability is poor, and the adhesive application surface is small and it is not easy to be bonded.
The UV-shaped corrugated file is between the U-shaped corrugated file and the V-shaped corrugated fiber, and the radius of the arc is also between the two. Therefore, both the advantages of the corrugated corrugated fiber are high in the compressive strength and the load-carrying ability, and the rigidity, the shock resistance, and the elasticity are both Better, so it is used in all kinds of packaging.
2. There are four types of corrugated corrugated corrugated board: coarse corrugated A, small corrugated B, medium corrugated C, and fine corrugated E. Various corrugated dimensions are shown in Table 3-57.
Type A, B, and C corrugated paperboards are used for outer packaging: B and D corrugated paperboards are used for inner packaging; D corrugated cardboards are thin and hard due to the large number of corrugated sheets per unit length. With beautiful appearance and smooth surface, it can be used for surface decoration and printing. It is widely used in packaging of various small household appliances, hardware and wine products.
Table 3-57 Corrugated Board Types and Sizes
(2) Double-faced corrugated cardboard (as shown in Fig. 3-78, No. 2) is affixed with noodles on both sides of the corrugating medium. At present, this kind of double-faced corrugated cardboard is used for making cartons.
(3) Double-sided double corrugated cardboard (shown as 3 in Fig. 3-78) is a five-layer paperboard composed of double-layer corrugated paper and face paper. Due to its good strength and shock resistance, it is mostly used for packaging of fragile or heavy items.
(4) The double-faced three-wall corrugated paperboard is composed of three layers of corrugated paper and noodles. It is a seven-layer paperboard. Due to its high strength and strong load-bearing capacity, it is mainly used for the packaging of heavy goods, as a transportation package, or as High-strength pad for use.
(3) Printability of Corrugated Cardboard Corrugated cardboard is used as a material for cartons. To adapt to the needs of sales and transportation, to facilitate the stacking of packaged goods, and to prevent shock and shatter during transportation, loading and unloading, it should have rigidity, hardness, Pressure resistance, breaking resistance and elasticity. For this reason, a relatively high amount of corrugated base paper and high-quality adhesives must be used to prevent the corrugation from deforming or being loosely adhered, which reduces the plane compressive strength of the corrugated paper.
Corrugated cardboard should have a smooth surface, suitable for printing a variety of text or pattern, and the surface strength, ink absorption performance and dimensional stability of corrugated cardboard face paper often affect the quality of printing. The corrugated paper produced from ground paper pulp facilitates the printing of high-quality advertising graphics.
Cardboard used in corrugated board is sensitive to the relative humidity of the environment. When the corrugated board absorbs moisture, its compressive strength is greatly reduced. In order to improve the waterproof performance of corrugated boxes, the strength of the cartons during storage and transportation is ensured. The surface of the carton should be waterproofed.
Second, the corrugated board raw and auxiliary materials (a) of the main paperboard materials used in corrugated board 1. Box cardboard box cardboard is made from chemical straw. Advanced cardboard is mixed with hemp fiber and is called hemp paper. It has high folding and bursting resistance. It is mainly used for bonding corrugated cardboard with corrugated paper. There are domestic and imported cardboard boxes. Domestic paper can be divided into four grades: special number (kraft linerboard), No. 1 (strong linerboard), ordinary and hydrocarbon linerboard. There are also noodles and no-nosed noodles. Noodle board paper is generally flat and smooth, suitable for printing and oiling.
2. Corrugated base paper Corrugated paper is a low-quantity thin paperboard made from brown ground wood pulp and chemical wood pulp. According to different papermaking raw materials, it can be divided into three types: semi-chemical wood pulp corrugated paper, straw pulp corrugated paper and waste paper corrugated paper. Mainly used for high-temperature machining into corrugated core paper, and corrugated cardboard made of corrugated cardboard. Has good elasticity, shock absorption and impact resistance.
3. The tea board is made from recycled waste paper and cement bag paper. The surface layer is pulp noodle and the color is tea-brown. It is called tea board paper. Degree of 250-300g/m2 can be made of corrugated cardboard face paper.
4. White paperboard White paperboard is a kind of white noodle board, the raw material is chemical wood pulp, and the surface layer is bleached wood pulp. According to the color of the bottom of cardboard, it can be divided into two types: gray and white, and it is properly calendered, powdered and general. Uncalendered paper is rough and poorly printed. Because the powdered white board is coated, it does not seep when printing, so the amount is small, the color is bright, and the small-sized corrugated boxes of small household appliances and wine packaging are used.
5. Synthetic paper made of calcium plastic These papers (or paperboards) such as double, triple, and five-layer corrugated paper, etc. In the past, it was completely compounded with vegetable fiber base paper. It combines the corrugated base paper with different cardboard after it is tiled, and its products are mainly used for making various cartons and cartons. However, the cardboard boxes and cartons made of this kind of composite cardboard have certain problems in terms of pressure resistance, waterproofness and moisture resistance. Therefore, in some developed countries in the world, calcium plastic paper composites are used to form calcium plastic corrugated cardboard. Made of cardboard boxes and so on. This carton solves the problems of cartons and cartons made from plant fiber paper. Lithium-plastic paper is non-plant fiber paper. Its production process and principle are completely different from wet-process fiber paper. Now it is only briefly introduced.
(1) Production process of calcium plastic synthetic paper The production of calcium plastic synthetic paper is generally composed of several processes such as batching, kneading, smelting, rolling and cooling. In this process, the raw materials are first added at a high ratio according to the ratio. In the machine, the calcium plastic material is rapidly mixed and then entered into an internal mixer. In the internal mixer, the calcium plastic material is pressurized and heated, and under the strong stirring and shearing action of the rotor, it is initially plasticized and mixed evenly, and then it is further plasticized and mixed in a two-roller machine. Has reached the plasticization and mixing uniform calcium plastic material, into the four-roll calendar machine extrusion extension, made of calcium plastic paper.
(2) Raw material ratio The raw materials for the use of calcium plastic synthetic paper include resins, fillers and additives. Different types of paper use different raw materials and ratios. Table 3-58 shows the typical raw material ratios for the two papers.
Table 3-58 Raw material ratio of synthetic plastic paper
