聚乙烯在内心层形式的封条，使整套液气密性，并提供一个保护性涂层对外部，以保持包装干燥。
Polyethylene in the innermost layer forms the seals that make the package liquid-tight and provides a protective coating on the exterior to keep the package dry.
用环氧和有机硅树脂涂料对由聚乙烯／炭黑（PE／CB）制备的正温度系数（PTC）电路保护元件的表面处理及其工艺进行了研究。
The packaging materials and processes of positive temperature coefficient (PTC) devices made up of the composite of polyethylene and carbon black(PE/CB) for over current protection were studied.
在所有塑料中，它具有最高的阻气性能，大约是普通聚乙烯的10,000倍，这使它成为可用来保护食品的最佳材料。
It has the highest gas-impermeability of any plastic, about 10,000 times that of ordinary polyethylene, which makes it an excellent material for preserving food.
应用推荐