近几年来,以泡沫聚乙烯作为介质材料越来越普遍了。在本公司电线电缆中所采用的泡沫材料称为“pely foam”,它是种采用情性气体作为发泡剂,在塑料内部形成全封闭小泡的聚乙烯。这种泡沫绝缘能使我们把电缆设计得具有低损耗,轻重重,低价格,因为它的介电常数为1.5,而实芯聚乙烯为2.26。我们采用在控制下能放出大量气体的热敏发泡剂来使聚乙烯发泡。 In recent years, it has become more and more common to use foamed polyethylene as a dielectric material. The foam used in our wire and cable is called “pely foam,” a type of polyethylene that uses an inert gas as a blowing agent to form fully enclosed vesicles inside a plastic. This foam insulation allows us to design the cable with low loss, light weight, and low price because of its dielectric constant of 1.5 and that of solid polyethylene of 2.26. We use a thermal foaming agent that emits a large amount of gas under control to foam the polyethylene.