In these comparings,number l to 6 indicates the feature degree from good to bad and the negative sign(—)indcated the materials cannot be applied to here.品名对照：PFA—可溶性聚四氟氯乙烯 PTFE—聚四氟乙烯 ECTFE—乙烯三氟氯乙
*在这些比较中，数字1至6分别表示性能的优至劣，负的符号（—）表示材料不可作该应用。
*In these comparings,number l to 6 indicates the feature degree from good to bad and the negative sign(—)indcated the materials cannot be applied to here.
