It is pointed out that congo-red test, dynamic heat stability test, oven test and UV lamp test are not so efficacious because the adverse factor is single, and there is some difference between the test result and the actual property.

• 指出刚果红试验、动态热稳定性试验、烘箱试验、紫外灯照射试验等4种试验方法因破坏因素单一而距异型材的实际老化情况有一定差距;