However, the main structure of plastic flexible packaging materials are plastic polymers, has some permeability to gas, and therefore can not fully replace the metal and glass packaging.

然而塑料软包装材料主体结构是塑料聚合物，对气体有一定的渗透性，因此并不能完全代替金属、玻璃包装。

youdao

Nitrogen gas with different displacing velocity and pressure was used to displace the core in testing, the permeability damage and correlation analysis caused by velocity sensitivity were obtained.

实验用氮气以不同的驱替速度和驱替压差驱替岩心，得到由速敏性引起的渗透率损害及相关分析结果。

youdao

One of the main methods to test the gas permeability is using partial pressure difference.

用压差法测试塑料薄膜的透气性，是一个长期使用的主流测试方法。

youdao

Schneck is also going after the vision business, laying claim to the treatment of contact lens surfaces, which determines the gas permeability of soft contacts.

FORBES: Magazine Article