Key words: PVC core material, PVC composite board, sandwich board, RV wallboard
introduce
Compared with the mainstream materials (aluminum alloy frame wall panel, wood frame wall panel and steel frame wall panel) in the RV market, the "PVC core sandwich composite sandwich panel" uses FRP skin or aluminum skin as the wall panel skin, and the PVC structural foam independently produced by Tiansheng is the isolation layer material, which meets the lightweight requirements and performance requirements. Provide better thermal insulation and sound insulation performance.
1? Overview of PVC structural foam
PVC structural foam is a patented product of Tiansheng New Materials, which adopts interpenetrating foaming technology to break foreign monopoly and realize industrialization.
Light weight, no water absorption, excellent specific stiffness and specific strength;
It has good dimensional stability and machinability;
Compatible with various resin systems, it is an ideal core material for light and high strength composite sandwich structure;
? Provide excellent fatigue resistance, impact resistance and shock absorption, and can play the role of sound insulation and heat insulation;
? Not easy to be damp and moldy, acid and alkali resistant, moth-proof, good flame retardant;
? The processing temperature is -240℃~+ 100℃, and the long-term use temperature is -240℃~+80℃.
The density range is 45-250kg/m3;
1. 1 The following figure shows the performance parameters of P60 structural foam for RV.
1.2 sandwich composite structure
Sandwich composite structure is a special type of composite structure. Sandwich structure consists of two thin and strong panels glued to both sides of a light and relatively thick core material. Sandwich structure has the typical characteristics of light weight, high stiffness and high strength. ?
2? Types of RV wallboard
There are many kinds of plates used in RV shell, and the connection methods between plates are also different. Each plate has its own characteristics and scope of application. ? According to the different core materials, it can be divided into: wood skeleton composite board, metal skeleton composite board and nonmetal skeleton composite board.
The main external skins are: glass fiber reinforced plastic (FRP/GRP), aluminum plate, multi-layer board, fireproof board, etc.
Wood skeleton is traditional, and many enterprises at home and abroad are applying it. Its characteristics are: convenient processing, low cost, light weight and good nail holding power, but it also has some limitations, such as easy deformation.
2.2 Metal skeleton (aluminum skeleton/steel skeleton)
Metal skeleton wallboard, with high strength and strong processability, can be roughly divided into aluminum alloy skeleton and carbon steel skeleton. The wallboard of aluminum alloy skeleton is lighter than that of carbon steel skeleton, and the internal filling materials are generally XPS and EPS.
2.3 Non-metallic skeleton wallboard
Non-metallic skeleton, a high-density material made of PVC or PU, is about 400-600kg/m3, which is similar to the density of wood square. When it has better corrosion resistance and stable physical properties, it is far stronger than wood square, so many manufacturers at home and abroad have turned to the application of non-metallic skeleton technology mode.
2.4 Skeleton-free wallboard (PVC composite board)
Skeleton-free wallboard means that there is no skeleton embedded in the wallboard, and its strength is guaranteed by PVC structural foam. It is characterized by light weight, high strength, good thermal insulation and high production efficiency, but it also has its limitations, such as poor nail holding power.
3? Characteristics of PVC composite board
All products of Tiansheng RV shell wallboard adopt sandwich composite structure, which is convenient to install and can be directly cut and polished on site according to the installation needs. Because there is no skeleton restriction, the opening position of doors and windows on wallboard can be adjusted at will, that is, wallboard can be used as the standard of different projects.
Take 1.5mm thick glass steel plate and 25mm thick PVC structural foam plate with a total thickness of 28.5 mm as examples, the unit plane mass is only 7.9kg/? M3, compared with other embedded bones, the maximum energy per square can be 30% lighter. The thermal conductivity of the wall without cold and hot insulation technology is very low, which is lower than 0.03 W/(m k). This means that the RV with PVC composite board should be warm in winter and cool in summer, especially in extremely cold and hot areas, and your air conditioning power consumption will be lower and lighter.
4? Application of PVC composite board in RV
4. 1? Application of PVC composite board in RV wallboard
The application of PVC composite board in RV wallboard adopts two-sided 1.5mm thick glass steel plates and 25mm thick PVC structural foam plates, with a total thickness of 28.5mm, and a glue layer with a thickness of 0.25mm is left between the glass steel plates and the PVC structural foam plates. In order to meet the stiffness and seismic performance of wallboard, adhesive bonding is the most suitable assembly process. See the figure below for the detailed structure.
4.2 Application of PVC Composite Board in RV Floor
The application of PVC composite board in RV floor consists of 1mm glass steel plate, 20mmPVC structural foam, 5mm multilayer board and 2mmPVC floor leather from bottom to top. The thickness of each layer is 0.25 mm, and the total thickness is 28.75 mm. First, the glass steel plate, PVC structural foam and multilayer board are compounded, and then the PVC floor leather and multilayer board are glued and flattened. The operation is simple and convenient, and the structure is shown in the following figure.
The floor made by this scheme is lighter 1/3 than the floor with the same thickness frame, and has good bearing capacity and thermal insulation performance. The glass steel plate at the bottom is bonded with on-site structural adhesive to form a frame structure with good torsional performance. At the same time, because the bottom is a glass plate, there is no need to worry about corrosion protection. The addition of multi-layer board solves the problem that the connection between furniture and floor in RV can be connected by angle code, and the bonding between floor leather and wood board is more convenient and reliable than that between floor leather and glass steel plate.
4.3 Application of PVC Composite Board in RV Roof
Most of the roofs of station wagons are open-molded, mainly because they are "raised" to prevent water accumulation and leakage, and can also be compounded with PVC structural foam. Here is a roof structure, which is suitable for RV with no opening at the top.
Adding aluminum square pipe beam at the top is to increase the strength of the top (mainly in the position where there is no furniture support inside) and to wire the top. Considering that the temperature difference between hot and cold will produce condensed water, the foam is ground off by 20mm instead of 25 mm.
4.4 RV application in indoor countertops and toilet boards
The table top inside the RV is made of boards cut from wallboard, which can reduce the garbage generated by wallboard cutting and improve the utilization rate of PVC composite board. On the other hand, the PVC composite board countertop can reach the stone countertop110, which greatly reduces the weight of the car. Compared with the wooden board, the countertop made of PVC composite board has good corrosion resistance. The section of the plate is closed with special T-shaped edge sealing, and the detailed structure is shown in the figure.
The application of PVC composite board in the vertical board of RV bathroom consists of 1mm aluminum plate (inside the bathroom), 12mmPVC structural foam, and 1mm fireproof board. The thickness of the adhesive layer is 0.25mm, and the total thickness is14.5mm. The PVC board mainly plays a waterproof role, which greatly improves the service life of the bathroom, and on the other hand, the lightweight design also reduces the self-weight. See the figure below for the detailed structure.
5? The future of PVC composite board
The application of sandwich composite sandwich panel with PVC core material in RV has laid a good technical foundation for the subsequent development of new RV products, and more and more RV companies use this panel.
Because of its light weight, high strength, good thermal insulation performance and no cold bridge, PVC composite board can also be used in electric cold train logistics vehicles.
In the future product research, the connection mode between PVC composite board and chassis needs to be explored continuously, and the gap between PVC composite board and traditional RV board should be narrowed in cost.
6? Concluding remarks
The development of RV is inseparable from the upgrading of basic materials. However, domestic RV enterprises pay attention to the downstream end products of RV industry, and obviously pay insufficient attention to materials, which leads to the serious convergence of RV end products, although diversified.
As an imported product, RV has been on the domestic market for more than 20 years. During this period, RV has been gradually accepted by more people, and at the same time, it has quietly changed its localization. The "localization" of RV substrate is very slow. Looking forward to the future, the sandwich composite sandwich panel with PVC core material will be more and more widely used in RV by virtue of its product advantages.
refer to
Xu Xiaohua, Qian Bin. Composite plate and RV made of composite plate:
[2] GB/T 77 14 Wang Tie, Zhang Xu, Li,, et al. A detachable FRP RV shell.
[3] GB/T 77 14 anonymous. Application of German Lamilux composite in light passenger cars [J]. FRP/composites