Application analysis of functional polycarbonate board on the side window glass of urban rail transit vehicles
With the development of the rail transit industry, the market has put forward higher requirements for the lightweight and energy-saving vehicles. As an important part of the vehicle, the lightweight research of the vehicle side window has become a major direction of the whole vehicle lightweight. Compared with the toughened glass, the polycarbonate plate (PC) has the characteristics of light quality, good impact resistance, good heat insulation and low cost, and has the ability to replace the traditional vehicle glass.
PC board features
Lightweight characteristics
Compared with the toughened glass, the density of the PC plate is reduced by 50%, which meets the larger side wall window, but also meets the lightweight requirements of the vehicle.
resistance to impact
The PC board has an excellent impact resistance.
Comparing the PC plate with the laminated glass, the thermal conductivity is improved by 25%, which not only improves the comfort of the vehicle user inside, but also helps to maintain the constant temperature in the passenger room. From the long-term operation of the vehicle, PC board can effectively reduce the HVAC power consumption of the vehicle and reduce the heating and cooling costs for the operating department.
machinability
PC board has good machining and modeling freedom, can be cut, drilling, and bending, etc. According to the shape of the car body can be designed to the shape of various 3 dimensional effect. In addition, the PC plate itself has good stiffness and no sharp edges, so there is no need to do edge grinding, steel, sandwich and other complex processes like safety glass. Compared to the existing type FRAII-laminated glass, the cost savings are up to 20%. The PC panels can be configured in a variety of colors, which can meet the different requirements of the solar energy transmission ratio and the visible light transmission rate of the rail vehicle Windows.
Anti-wear scratch and anti-aging
Restricted by material properties, the wear and aging resistance of PC plate are lower than those of tempered glass. For a single plate without surface treatment, the grinding test was conducted according to ASTM D1044 standard. Under the condition of 500g loading and 1000 rotary grinding, the surface fog difference of PC plate exceeds 30%, while the fog difference on the surface of tempered glass is only 0.26% under the same test conditions.
PC plate has poor weather resistance. If exposed to sunlight for a long time, the influence of ultraviolet radiation will accelerate the aging, the color will be yellow, and the impact resistance and other mechanical properties will be reduced. In terms of car Windows, due to the operation needs, the plate will be exposed to the outdoor environment for a long time. For transparent Windows, its aging yellow is very obvious in appearance. at the same time, the traces left by long-term wear will also affect the field of vision and appearance, resulting in frequent replacement in the life cycle of the plate. Therefore, the traditional PC board cannot meet the rail vehicle window use requirements.
PC board performance improvement
To improve the wear and aging resistance of PC plates, the surface must be coated with hardened coating. After the surface hardening treatment, the surface wear resistance of PC plate is improved significantly.
At the same time, the hardened coating on its surface can filter out more than 90% of the ultraviolet light, improving the anti-aging resistance of the plate while ensuring the passenger comfort in the passenger room.
PC plate has poor weather resistance. If exposed to sunlight for a long time, the influence of ultraviolet radiation will accelerate the aging, the color will be yellow, and the impact resistance and other mechanical properties will be reduced. In terms of car Windows, due to the operation needs, the plate will be exposed to the outdoor environment for a long time. For transparent Windows, its aging yellow is very obvious in appearance. at the same time, the traces left by long-term wear will also affect the field of vision and appearance, resulting in frequent replacement in the life cycle of the plate. Therefore, the traditional PC board cannot meet the rail vehicle window use requirements.
PC board performance improvement
To improve the wear and aging resistance of PC plates, the surface must be coated with hardened coating. After the surface hardening treatment, the surface wear resistance of PC plate is improved significantly.
At the same time, the hardened coating on its surface can filter out more than 90% of the ultraviolet light, improving the anti-aging resistance of the plate while ensuring the passenger comfort in the passenger room.