"Eva" usually refers to ethylene-vinyl acetate copolymer (EVA), while "pet" usually refers to polyethylene terephthalate (PET), 

Chinese name polyester or polyethylene terephthalate, which is a commonly used plastic material.

Weather resistance refers to the ability of the material to resist the influence of external factors such as light, temperature 

change, humidity and rain when exposed outdoors or in a similar environment. Usually such properties are related to the 

chemical structure of the material itself and additives.

EVA is an elastic material with good softness, transparency, gloss, tear resistance, as well as resistance to chemicals and 

environmental stress cracking. It is widely used in sole manufacturing, health protection equipment, packaging materials 

and so on. However, its resistance to UV light is relatively poor, it is easy to age, and if it is used for outdoor applications, 

it is usually necessary to add light resistant or anti-ultraviolet stabilizer to improve its weather resistance.

In contrast, PET has good mechanical properties and temperature and chemical resistance, and is a kind of plastic with high 

hardness and good stability. PET has good weather resistance, but it can also be damaged when exposed to outdoor 

ultraviolet light for a long time, which may cause aging and brittleness.

In general, if the weather resistance of EVA and PET is to be compared, it is generally believed that the weather resistance 

of PET is better than that of EVA without special treatment. However, these materials are often modified appropriately in 

specific applications to improve their properties, and these modification factors need to be considered when comparing 

weather resistance.