Why use PC instead of PMMA for automotive headlight housings?

Why use PC instead of PMMA for automotive headlight housings?

PC and PMMA both have high transparency and good processing characteristics, but there are some differences in the application of headlights. First of all, in the heat-resistant temperature, PC can generally reach 130 ℃, while PMMA only 100 ℃ or so. Secondly, the toughness of PC material is better, while PMMA material is very brittle, easily broken by the impact. Finally, the unit price of PC is higher than PMMA, and the liquidity of the form is not as good as PMMA. generally, the headlights of the lampshade are PC, which is mainly due to the high illumination of the headlights, the heat emitted by the large, and in the front of the car, which requires a heat-resistant, but also able to resist the impact of the material. Rear taillight lampshade are generally PMMA, in addition to the cheap factor, the rear taillight is generally a single function of the signal lamp combination, the need for red and transparent two-color interspersed, so the fluidity of good PMMA is the right choice.