PP plastics contain unstable tertiary carbon groups, which, upon exposure to light, heat, and oxygen, are prone to aging and degradation, leading to discoloration and decreased performance. This limitation restricts their use in outdoor products. To make PP plastics more suitable for outdoor electrical appliances, it is necessary to conduct weather-resistant modification. Weather-resistant PP modified plastics can significantly extend their lifespan under harsh outdoor weather conditions. This type of modified PP plastic is primarily used for manufacturing household appliances that are used outdoors year-round, particularly for the exterior shells of air conditioners, replacing traditional metal spray-painted shells.

Outdoor air conditioner casings must withstand various weather conditions such as sun exposure, rain, and extreme cold, while meeting long-term usage requirements. The use of PP modified plastic instead of metal electrostatic powder coating technology was introduced in the early 1990s. This technology overcomes the shortcomings of the original metal electrostatic powder coating casings, such as complex manufacturing processes, high costs, heavy weight, and susceptibility to rust (which can affect the overall performance and lifespan of the unit), thereby reducing labor intensity, lowering energy consumption, and extending the lifespan. Besides the outdoor air conditioner casings, the axial flow blades of outdoor air conditioners and the outlets of heating fans also utilize weather-resistant PP modified plastic. In recent years, with the increase in air conditioner production, the application of weather-resistant PP modified plastic in this product market has also gradually increased.