Architectural plastic are a general term for plastic products used in construction projects. Common molding methods for manufacturing architectural plastic products include: calendering, extrusion, injection, molding, coating, lamination, etc.

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A general term for plastic products used in construction projects.

The main component of plastic is synthetic resin. According to the different properties of resins and products, different additives are required, such as stabilizers, plasticizers, reinforcing agents, fillers, colorants, etc. Plastic are divided into thermoplastic and thermosetting plastic. Plastic that can be softened by heating, hardened by cooling, and can be processed repeatedly within a specific temperature range are collectively referred to as thermoplastic, such as polyvinyl chloride, polyethylene, polypropylene, polystyrene, etc. Those that cannot be softened after being heated or solidified under certain conditions are collectively referred to as thermosetting plastic, such as phenolic plastic, amino plastic, etc. Plastic can be processed into products of various shapes and colors, with simple processing methods, high degree of automation, and low production energy consumption. Therefore, plastic products have been widely used in industry, agriculture, construction and daily necessities. Common molding methods for manufacturing architectural plastic products include: calendering, extrusion, injection, molding, coating, lamination, etc.

Plastic are light in weight, good insulators of heat and electricity, and have strong resistance to chemical corrosion. When processing certain plastic, appropriately changing the amount of plasticizers and reinforcing agents can produce soft or hard products suitable for various purposes. Plastic have a low elastic modulus, are prone to deformation, have a large thermal expansion coefficient, and poor flame retardancy, but they can be improved through reinforcement, compounding, and appropriate application. Some strength-to-weight ratios of glass fiber reinforced plastic are even higher than those of steel.

Plastic are mostly used for non-structural materials in construction. Only a small part is used to manufacture structural components that bear light loads, such as plastic corrugated tiles, waiting sheds, kiosks, water storage towers, inflatable structures, etc. However, more of them are used in combination with other materials to give full play to the characteristics of plastic, such as used as coating insulation materials for wires, veneer materials for artificial boards, various composite exterior wall panels with foam plastic sandwich layers, roof panels, etc. Therefore, architectural plastic are a building material with broad development prospects.

There are many types of building plastic products, mainly the following:

Plastic pipes and fittings Pipes and fittings made of plastic have been widely used in pipeline projects such as indoor drainage, tap water, chemicals and wire threading pipes. Commonly used plastic include rigid polyvinyl chloride, polyethylene, polypropylene and ABS plastic (copolymer of acrylonitrile-butadiene-styrene). The main advantages of plastic drainage pipes are corrosion resistance and low fluid friction; since it is difficult for debris flowing through to adhere to the pipe wall, the sewage discharge efficiency is high. The weight of plastic pipes is light, only 1/6 to 1/12 of the weight of cast iron pipes, which can save labor, and its price and construction cost are lower than cast iron pipes. The disadvantage is that the linear expansion coefficient of plastic is about 5 times larger than that of cast iron, so flexible joints need to be set on longer plastic pipelines. Extrusion molding is mostly used to manufacture plastic pipes, and injection molding is mostly used for pipe fittings. In addition to the gluing method, the connection methods of plastic pipes also include hot welding, threaded connection, flange connection, and socket connection with rubber sealing ring.

When pressurized liquid passes through a PVC pipe, the liquid temperature shall not exceed 38буC. If it is a non-pressure pipeline (such as an indoor drain pipe), the temperature of the liquid passing continuously shall not exceed 66буC; the temperature of the liquid passing intermittently shall not exceed 82буC. When PVC plastic is used in water supply pipes, toxic stabilizers and other raw materials are not allowed to be used.

Elastic flooring Plastic elastic flooring is divided into two categories: semi-rigid PVC floor tiles and elastic PVC coiled flooring. The basic size of the floor tile is a square with a side length of 300 mm and a thickness of 1.5 mm. Its main raw materials are polyvinyl chloride or a copolymer of vinyl chloride and vinyl acetate, and the fillers are heavy calcium carbonate powder and short-fiber asbestos powder. The surface of the product can have a wear-resistant coating, color pattern or concave-convex pattern. According to regulations, the residual depression of the product shall not be greater than 0.15 mm, and the wear amount shall not be greater than 0.02 mg/cm2.

The advantages of elastic polyvinyl chloride coil floor are: less joints on the ground, easy to keep clean; good elasticity, comfortable walking feeling; good thermal insulation and sound absorption performance. The composite use of polyvinyl chloride foam floor with a thickness of 3.5 mm and an apparent specific gravity of 0.6 and a hollow reinforced concrete floor with a thickness of 120 mm can reduce the heat transfer coefficient by 15% and absorb impact noise up to 36 decibels. The width of the coil floor is 900-2400 mm, the thickness is 1.8-3.5 mm, and the length of each roll is 20 meters. The commonly used non-foamed laminated plastic floor in public buildings has a transparent wear-resistant layer on the surface, and the lower layer is printed with patterns. Asbestos paper or glass cloth can be used for the bottom layer. The laminated plastic floor with a foaming layer in the middle is used for residential buildings. The adhesives used to bond plastic floors and floor surfaces include chloroprene rubber emulsion, polyvinyl acetate emulsion or epoxy resin.

Chemical fiber carpets are new products that appeared after 1945. Their usage has quickly exceeded that of carpets made of traditional raw materials such as wool. The main materials are nylon filaments, nylon staple fibers, acrylonitrile, cellulose and polypropylene. The main performance of carpets is wear resistance, elasticity, dirt resistance and stain resistance, easy cleaning and difficulty in generating static electricity. The performance of acrylonitrile, nylon and polypropylene fibers can be compared with wool. Chemical fiber carpets have a variety of weaving methods, and the thickness is generally in the range of 4 to 22 mm. Its main advantage is comfortable walking, and its disadvantages are static electricity, easy dust accumulation and difficulty in cleaning. Similar to carpets are non-woven carpets, which are also made of chemical fibers.

Plastic doors and windows and indoor plastic decoration accessories In the past 20 years, due to the continuous development of thin-walled hollow profile extrusion technology and foaming extrusion technology, door and window frames, cabinet components and various indoor decoration accessories welded with plastic profiles have achieved significant development and have been valued by many countries with wood and energy shortages. Interior decoration accessories made of rigid foamed polyvinyl chloride or polystyrene are often used in wall panel corners, door and window pressure strips, gypsum board caulking strips, skirting boards, mirror hanging lines, ceiling return edges, stair handrails, etc. It also has the dual functions of architectural structural components and artistic decorations, which can not only improve the decoration level of buildings, but also give full play to the advantages of plastic products with beautiful appearance and easy processing.

Plastic wallpaper and veneer board Polyvinyl chloride plastic wallpaper is a high-quality finishing material for decorating indoor walls. It can be made into a variety of printed, embossed or foamed beautiful three-dimensional patterns. This wallpaper has certain air permeability, flame retardancy and pollution resistance. The surface can be washed with clean water, and there is a layer of base paper on the back, which is convenient for using various water-soluble glues to stick the wallpaper on a flat wall. Transparent paper impregnated with melamine formaldehyde resin liquid is overlapped with book cover paper with wood grain or other patterns printed on the surface, and then hot pressed to form a hard plastic veneer; or printed paper impregnated with diallyl polyphthalate (DAP) is overlapped with medium-density fiberboard or other artificial boards, and then hot pressed to form decorative boards, which can be used as indoor partition boards, door core boards, furniture boards or floors.

Foamed plastic A lightweight porous product that is not easy to collapse and does not lose its insulation effect due to moisture absorption. It is an excellent insulation and sound absorption material. The product is in the form of plates, blocks or special shapes, and can also be sprayed on site. Among them, those with interconnected pores are called open-cell foam plastic, which have good sound absorption and cushioning properties; those with non-interconnected pores are called closed-cell foam plastic, which have lower thermal conductivity and water absorption. Polyurethane foam plastic, polystyrene foam plastic and urea-formaldehyde foam plastic are commonly used in construction. The advantage of polyurethane is that it can be foamed by spraying at the construction site. It has good adhesion with other wall materials and is resistant to mold erosion.

Glass fiber reinforced plastic Plastic products reinforced with thermosetting resins with glass fibers are usually called fiberglass. Commonly used in construction are transparent or translucent corrugated tiles, skylights, bathtubs, integrated toilets, foam sandwich panels, ventilation ducts, concrete formwork, etc. Its advantages are high strength-to-weight ratio, corrosion resistance, heat resistance and good electrical insulation. The thermosetting resins used in it are unsaturated polyester, epoxy resin and phenolic resin. The molding methods of fiberglass are generally hand lay-up molding, spray molding, winding molding and compression molding. Hand lay-up molding is to first spray a colored gelatinous surface layer on the surface of the mold shell so that the product has a beautiful and glossy surface after demoulding. Then, a glass cloth or glass felt layer soaked in a resin mixture is manually applied on the gelatinous layer, and demoulding can be performed after curing. The spraying method uses a special spray gun to spray the resin mixture and short glass fibers cut into about 2 to 3 cm long directly and evenly on the surface of the mold shell. Although the use of short fibers reduces the strength of FRP, its production efficiency is high and it can save labor. FRP pipes or tanks are mostly made by winding molding, that is, the glass fiber woven belt or long glass fiber bundle soaked in resin mixture is wound on the rotating tire mold according to the force direction of the product, and demolded after curing. Some tanks are lined with aluminum inner tubes to enhance the sealing of the tank. The molding method is to evenly stack thin sheets of glass fiber felt or cloth soaked in resin in the mold, and heat press them into various finished products, such as bathtubs, washbasins, etc. The inner and outer surfaces of the molding method products have beautiful and wear-resistant surfaces, and the production efficiency is high and the product quality is good. The rapidly developing architectural FRP products include cooling water towers, water storage towers, integral assembled toilets, semi-assembled toilets, etc.

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