外墙涂料的主要功用是装饰,同时还能对墙体材料起一定的保护、防水作用。由于城市环境污染情况较严重,一旦外墙涂料的涂膜被灰尘沾污,其装饰效果会大大降低, The main function of exterior paint is decoration, and at the same time, it can also protect and waterproof the wall material. Due to the serious environmental pollution in the city, once the exterior wall coating film is contaminated by dust, its decorative effect will be greatly reduced.