Application of Wood Plastic Composite Materials in Construction

Wood plastic composite (WPC) is a composite material formed by mixing polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC) thermoplastic polymer with plant fibers such as waste wood, bamboo, and crop straw, a certain proportion of inorganic fillers, and additives (lubricants, coupling agents, antioxidants, etc.) through extrusion, molding, or injection molding processes.

Wood plastic board is a board formed by hot extrusion of plant fibers, thermoplastic plastics, and other additives mixed in a certain proportion. Wood plastic decorative wall panel is a decorative wood plastic composite board installed on the wall. When used for interior wall decoration in civil buildings, it is called interior decorative wall panel, and when used for exterior wall decoration in buildings, it is called outdoor decorative wall panel. There are currently four main applications of wood plastic composite materials in prefabricated buildings: one is used as exterior decorative materials for walls, including external cladding panels and hollow exterior wall decorative panels; Secondly, there are lightweight foam decorative panels used as interior decorative materials for walls; Thirdly, wood plastic composite wall panels; The fourth is as a material layer for light steel keel composite walls.

As an exterior decorative material for building walls, it should first meet the requirements of building safety and functionality. Wood plastic outdoor decorative wall panels are suitable for low rise or partially multi story civil building outdoor wall decoration projects in areas with seismic fortification intensity not exceeding 8 degrees. Including low rise prefabricated wooden houses, homestays, vacation homes, house repairs, and other fields.

The installation method of outdoor wall panels currently does not have standard technical requirements for the installation of wood plastic exterior decorative panels, and the installation methods of various manufacturers are also different. There are no specific requirements or regulations for different installation heights, installation methods of hollow block base walls, and wall repair and renovation projects. Keels are generally divided into wood plastic keel, steel keel, and aluminum alloy keel. For large-span structures, steel keels are used; For small spans, aluminum alloy keels are used. The height of the keel is generally between 20mm and 30mm. The investigation found that when there are insulation performance requirements for the exterior wall, insulation materials (A-grade glass wool board or felt) are installed on the inner side of the keel, as well as between the keels. However, this insulation material is discontinuous and has a certain impact on the insulation performance of the wall

2.1 Design Requirements

 The wood plastic composite panel is connected to the base layer through the keel, and the setting of embedded parts should comply with the current industry standard "Technical Specification for Artificial Board Curtain Wall Engineering" JGJ336. The design of outdoor wall decoration engineering should include: selection of outdoor decorative wall panels; Performance design of outdoor wall decoration system; Requirements for keel setting; Installation design of outdoor decorative wall panels; Requirements for the installation of buckles, fasteners, and anchor bolts; Construction measures for hanging objects; Structural design of special parts such as edge closure, mouth closure, internal corners, and external corners; Waterproof, moisture-proof, and fire-resistant structural design. The performance design of the decoration system includes fire protection design, thermal design, lightning protection design, wind pressure resistance performance, and seismic performance design.