Plastic materials have a wide range of applications in the manufacturing of vehicle radar. Ordinary plastics (such as polycarbonate) have low cost and good manufacturing plasticity. With the trend of autonomous driving, more and more radar sensors will be installed in future cars. PC materials not only play a role in transparent car logo decorations, but also need to meet the transmission requirements of millimeter wave radar systems in integrated enclosed heat dissipation grilles and panoramic sunroofs.

The dielectric constant of polycarbonate (PC) material is slightly higher than PPS, PTFE, etc., but it has good wave transmission, relatively low cost, easy processing, and meets the requirements of weather resistance and lightweight, with good appearance effect. Therefore, PC material is the mainstream choice for the main material of millimeter wave radar exterior decoration.

PC material is one of the commonly used engineering plastics, which inherently has good weather resistance. The use of surface hardening treatment and other technical processes can further improve the service life of the product. It is understood that the material properties of such PC products will not be greatly affected in long-term external environments, and their lifespan can be up to 20 years.

Polypropylene (PP) is also a high polymer material widely used in automotive plastics, with excellent chemical resistance, simple processing, and low cost. It is suitable for use in automotive instrument panels, battery pack casings, door guards, pillars, seat guards, bumpers, and other materials. PP flame retardancy is poor before the addition of flame retardants, with a limit oxygen index (LOI) of 17 8%, flammable after an accident. The dielectric properties of polymer materials are determined by the properties and arrangement of bonds in the main chain structure. The stronger the polarity of the molecular structure, the larger the ε and tan δ values; The polarization degree of non-polar materials is small, and both ε and tan δ are small. By analyzing the principle of high polymer dielectric properties and comparing the test results in Table 1, the low polarity of polypropylene makes it more suitable as an electromagnetic wave transmitting material compared to other common plastics. In theory, using pure PP material as the ACC millimeter wave radar cover for the bumper skin has the best wave transmission performance and minimal impact on the signal; But in order to meet the comprehensive performance requirements of car bumpers, such as rigidity, heat resistance, and low-speed collisions, PP materials are often modified. Today, I recommend this car radar bracket and shell made of plastic material, which can replace the basic SABIC PP EPDM M20PP plastic. It is an excellent electromagnetic wave blocking modified PP with high impact resistance, vibration resistance, and excellent processing performance. It is designed specifically for applications that require electromagnetic shielding in automotive radar brackets, casings, as well as medical, electronic, and electrical systems.