Printing > Section 3 Building Materials Printing In the twentieth century, when printing technology was highly developed, people praised printing technology like this: What surface can be printed except air and water. This means that as long as there is a certain shape of the object, it can be used as a substrate for graphic transfer. The content of industrial printing in this chapter just shows this point. Products such as electronic circuit boards, ceramic glass, and textiles have different shapes and different properties. However, they are objects of printing, and they become industrial products with certain use value through printing. The printing of building materials in this section also shows people the omnipotence of printing. The scraps and scraps from wood processing are processed into shavings and fiberboards like wood chips and fiberboards. The precious wood grain and beautiful marble pattern are then printed to make it an upscale architectural decoration material. It not only makes full use of it. Natural resources have turned waste into treasure, and also decorated the living room and space to beautify people's lives. Printing> First, wood printing Wood, steel, and cement are listed as the top three materials of construction. With the advancement of social civilization and the development of economic construction, wood has increasingly become an important consumable material for construction, vehicle and boat manufacturing, and furniture production. However, China is a country with a low forest area coverage and a shortage of timber resources. Therefore, how to save wood and make comprehensive use of wood instead of other materials has always been an issue of concern to everyone. Woodgrain printing is an effective way to make full use of timber resources and increase the value of timber. Since the 1950s, wood grain printing has been studied in the building materials industry. 1. Printed wood grain veneer Precious wood color is well-proportioned, beautiful texture, but the limited number, the price is expensive; while ordinary wood, such as beech, birch, although the price is low, but the wood grain is not obvious. Some wood-based panels, such as particleboard, plywood, fiberboard, and other rough surface and aesthetic appearance. The original wood pattern of precious wood is used as the original, and then the color separation is made into a gravure, the pattern is printed on the overlay paper, and then the wood-printed overlay paper is attached to the substrate board of the artificial board or the common wood board. , it becomes a decorative timber with precious wood texture, which is printed wood veneer. (1) Printed veneer material. Woodgrain printing began in the late 1950s. Initially, gravure printing was used to produce precious wood patterns on gravure cylinders. However, unlike ordinary gravure cylinders, the woodgrain pattern on the cylinder at the time of platemaking needs to be endlessly processed. In other words, the wood grain on the entire drum has neither head nor tail, and the texture is circumferentially connected. The substrate is titanium white paper with 5 to 10% titanium dioxide as the filler. The screen is in gravure printing, with rich layers, soft colors and textures. (2) Impregnation Resin In order to make the overlay paper have better oil resistance, water resistance, acid resistance, rub resistance, and abrasion resistance, the veneer sheet after printing is put into a resin impregnating liquid for impregnation treatment. Early use of formaldehyde resin, but the product heat resistance, water resistance is poor, and later changed to melamine resin, polyester resin or dipropyl phthalate treatment, so that all gaps in the paper fiber are covered with resin, Thereby improving the various resistance of the overlay paper. After impregnating the resin, it should be immediately sent to the dryer for drying. (3) Hot pressing of veneer paper blanks. Decorative veneer paper is formed by hot pressing of multi-layer impregnated paper. The hot-pressed veneer paper not only has a beautiful appearance, but also has a certain thickness and mechanical strength, which is convenient for subsequent processing and use, and is also convenient for storage and transportation. (4) Substrate. All surfaces that need to be decorated can be used as substrates. The main requirements for the substrate are: flatness of the plate surface, uniform internal structure, certain mechanical strength and thickness, and suitable moisture content. Commonly used substrates include particleboard, plywood, and fiberboard. (5) Laminating the blank and the substrate. Laminated blanks can be laminated with the substrate after hot pressing. Use plywood as the substrate, its thickness should be greater than 7 mm; the thickness of the joinery board should be greater than 15 mm; the thickness of the particle board should be greater than 19 mm. If you need to use a thin artificial board as the substrate, you must use double-sided veneer processing, on the back of the substrate can be single-impregnated paper, not only on both sides of the substrate force balance, but also to further improve the appearance of the substrate image. 2. Artificial plate gravure printing Plywood Woodgrain printing is a traditional method of processing wood grain in building materials and has been used for decades. With the development of the wood-based panel industry, a more convenient method of wood grain printing, that is, surface decoration technology in which intaglio offset printing is performed directly on a wood-based board, has been rapidly developed (FIG. 22-1). Figure 22-1 Gravure offset printing of artificial wood Woodgrain direct printing has obvious advantages compared with veneer printing. Firstly, printing on the substrate directly saves woodgrain printed overlay paper, plastic film and other materials; secondly, the process is short, large-scale hot-pressing equipment is not needed, so the equipment investment is less; again, the auxiliary materials are consumed less, and the production efficiency is high. Therefore, the product cost is also low. (1) Surface finishing of the substrate. Wood grain directly printed substrates such as particleboard, etc., have relatively rough surfaces and must be surface-sanded, putty-coated, primed, and sanded to be printed on them. (2) gravure plain printing. Offset paper gravure printing its substrate is a paper, and gravure printing directly on the wood-based panel, the substrate is a flexible artificial wood. In order to make the ink in the gravure mesh pit transfer to the wood board, a gravure printing method is used, and it is not a metal gravure roll that directly contacts the artificial board, but an elastic rubber roller. This is a special gravure printing press for printing wood boards. The ink on the gravure cylinder is first transferred to the blanket cylinder, and then the blanket cylinder transfers the ink to the surface of the board. Each print has a set of rollers. The commonly used gravure offset printer is made up of three colors in series. The machine runs synchronously and the printing effect is better. (3) Surface finish. Printed boards require surface finishing. Commonly used surface finishing paints include nitro lacquer, alkyd varnish, polyurethane varnish and polyester lacquer. (4) Letterpress embossing. After three-color gravure printing and surface finishing, the color of the wood board is soft but the printing surface is smooth, lacking the texture feel of wood grain. In order to enhance the realism of the printed wood grain, the surface is further subjected to relief embossing. The structure of the embossing machine is relatively simple. With the method of mechanical engraving, an endless embossing embossing roller was made. After the board was embossed by the embossing roller, the surface of the board not only showed the pattern of the wood grain, but also the texture of the texture. 3. The aqueous ink printed wood grain printing and other printing differs from the other, the wood used is an aqueous gravure ink. Since water is used as a diluent, it is easy to formulate, there is no danger of fire, and no harm to the human body. In addition, because the water-based ink has low viscosity and good fluidity, the inking system of a printing machine is relatively simple. The common colors for woodgrain printing are red, yellow and black. The pigment is iron oxide. After different proportions of iron red, iron yellow and iron black, a series of different colors from red to yellow and from brown to black can be prepared. Iron red pigments are chemically stable, washable and light-resistant, and their colors remain unchanged over time. Veneer Printing> Second, plastic film veneer printing As a modern industrial product, plastic film shows its existence in various aspects such as industry, agriculture and people's daily life. Commonly used plastic films are polyvinyl chloride, polyethylene, polypropylene, polyester, polycarbonate, polyamines and so on. Among them, polyvinyl chloride film printing overlays are the most widely used decorative materials and have a history of 20 to 30 years. 1. Discharge treatment before printing of plastic film Plastic is a high-molecular polymer, because the lack of strong polar groups in the molecular structure, so its high chemical stability, acid resistance, resistance to hydrazine, oil resistance, water resistance. At room temperature, it is not dissolved by ordinary solvents and lacks the necessary affinity for printing inks. Therefore, if the surface of the plastic film is not specially processed, the ink printed on the surface of the plastic film will be weak, and it will fall off when rubbed. In order to enhance the affinity of the plastic film surface with the printing ink, discharge treatment is often used. Using high-frequency oscillation pulse high voltage, gas molecules in the air are ionized and discharge occurs. When the plastic film passes through the discharge gap, under the action of the pulsed arc, the smooth surface of the plastic film will generate burrs that are invisible to the naked eye. The binding of the film to the printing ink. 2. Plastic film printing and embossing Can print on plastic film, there are relief printing, gravure printing, screen printing and flexographic printing, but more is gravure printing. The four-color satellite gravure web press consists of three parts: unwinding, printing and rewinding. The printed pattern can be precious wood grain, beautiful marble, or other decorative patterns. In order to enhance the three-dimensional impression and texture of the printed pattern, the embossing process is also performed on the surface of the film after printing. The plastic film is a thermoplastic material. With this feature, the film is heated to 120-160°C, and then the pattern is embossed on the film with a patterned embossing roller. The cooling process is performed synchronously with the embossing process. After the film cools to room temperature, the embossed pattern on the film surface is fixedly formed. 3. Plastic film veneer process The printed and embossed plastic film has displayed beautiful wood grain or other pattern textures. Applying such a film to the surface of the wood-based panel becomes aesthetically pleasing and durable. Building decoration materials. The plastic film veneering process is similar to that of the printed veneer veneer processing technology, and the veneer is adhered to the base plate by pressing and compounding. (1) Adhesive for veneers Skin Scrubber Factory,Facial Skin Scrubber,Ultrasonic Face Cleaner,Ultrasound Skin Spatula,Custom Skin Scrubber Zhongshan Seven Cool Electronics Technology Co.,Ltd , https://www.gdsevencool.com