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Metal Sandwich Panel 

The production of metal sandwich panels in China started relatively late, the production process was outdated and the specifications were single, it is only used in prefabricated cold storage buildings from the early 1960s to the mid-1970s. With the continuous development of science and technology, the application of light steel buildings in industrial and civil buildings has led to the development of multifunctional new composite panels. Especially in recent years, the development of metal sandwich panels has been getting rapid, mainly characterized by

  • Light weight, high strength, and efficient insulation;

  • Convenient and fast construction;

  • Can be disassembled multiple times and installed and used repeatedly at different locations;

  • The surface has anti-corrosion coating and high durability.


Metal sandwich panel is a multifunctional new type of building material that integrates insulation, waterproofing, and load-bearing. It is widely used in the roofs, walls, and architectural decorations of light steel buildings, as well as in activity rooms and cold storage buildings.


Metal sandwich panels mainly come in several forms, including polystyrene sandwich panels, polyurethane sandwich panels, and rock wool sandwich panels. Among them, polystyrene sandwich panels are widely used in various industrial and civil buildings in China due to their low investment in production equipment and high production efficiency, which are very suitable for the needs of the domestic market. Polystyrene sandwich panel is made of color metal plate as the surface layer and self-extinguishing polystyrene foam as the core material. After the color steel plate is profiled by an automatic continuous molding machine, the color steel plate on the surface layer and the polystyrene plastic plate are pressed, heated and solidified with a high-strength adhesive to form a sandwich panel. The thicker core material plays a stabilizing and anti-compression deformation role on the metal surface, and has excellent cold insulation performance.


(1) There is currently a unified production standard for the specification of polystyrene sandwich panels. The product specifications and size deviations are divided into nine thicknesses according to the JC689-1998 "Metal faced polystyrene sandwich panel" building materials industry standard. The 75mm sandwich panel is usually used in environments above 0 ℃, with a thickness of 100mm for low temperatures below 0 ℃. There are generally two types of width according to the production equipment specifications. Due to continuous molding production, the length of metal sandwich panel can be determined according to work needs, but due to transportation reasons, it should generally not exceed 12000mm.


(2) Thermal conductivity: The insulation effect of metal sandwich panels is superior to other materials, and the insulation effect of metal sandwich panels with a thickness of 100mm far exceeds that of ordinary brick walls with a thickness of 490mm. However, due to its small capacity, poor stability, and low heat storage coefficient, this material is not suitable for intermittent heating rooms when used.


(3) Sound insulation effect: metal sandwich panels have good sound insulation. However, from the perspective of sound insulation principle, the sound insulation performance of lightweight structures with the same specifications is poor. When it is necessary to further improve the sound insulation capacity, other auxiliary measures can be taken, such as filling loose sound-absorbing materials in the wall, strengthening the sealing effect of assembly joints, etc.


Metal sandwich panel roof design structure is a prefabricated building material, but it is different from our commonly used reinforced concrete plate. Reinforced concrete slabs are generally difficult to cut, and gaps require secondary pouring. When making roofs, additional insulation and waterproofing layers are required. The width of metal sandwich panels in prefabricated production is generally fixed, but the length can be cut according to different requirements. Due to its surface being coated with colored steel plates, the material itself has strong waterproof ability, and there is no need to add waterproof materials when designing its roof. The roof can be designed as structural waterproof. At this point, in order to ensure smooth drainage and good waterproof sealing of the roof, it is crucial to do two aspects of work well, namely: joint construction treatment between roof panels and eaves construction treatment.


Under the conditions of transportation and lifting permission, longer sized metal sandwich panels should be used to reduce roof joints, prevent leakage, and improve insulation.

  • When the single slope length is less than 12m, the metal sandwich panel roof may not have transverse joints;

  • When it is greater than 12m, a transverse joint overlap should be set between the roof panels. To ensure waterproof effect, a certain overlap length must be met, and the size of the overlap length is related to the roof slope. When the slope is ≤ 1/10, it should generally not be less than 300mm. When the slope is greater than 1/10, it should generally not be less than 200mm and sealed with waterproof materials.

Therefore, in addition to effectively preventing water seepage, it can also prevent oxidation and corrosion at the steel plate incision.


The use of metal sandwich panels in building roofs integrates load-bearing, waterproof, and thermal insulation, with characteristics such as lightweight, high strength, and good thermal insulation, which can greatly improve building functionality and indoor environment. Adopting a reasonable metal sandwich panel roof construction plan and detailed node construction treatment is the key to ensuring smooth roof drainage and good waterproofing and sealing.

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