聚乙烯 chloride) 2.2 缩 EP(electro-polished 聚氯乙烯 PVC(polyvinyl 语 pipe) 电化学抛光低碳不锈钢管 BA(bright annealing 2.2.3 光亮低碳不锈钢管 2.2.2 2.2.4 PVDF(polyvinylidenefluoride) 2.2.1 聚偏氟乙烯 pipe) PE(polyethylene) 聚丙烯 PP(polypropylene) 2.2.5 2.2.6 略