Sealing for Industrial & Acid-rain Environments
工业污染与酸雨环境的封护适配
标签：工业大气, 酸雨, SO2, C4, 封护选型
按 ISO 9223，工业大气多为 C4 至 C5-I 级（SO₂ 年沉积 >80 mg/m²·d），硫酸盐对铜面的侵蚀速率是乡村环境的 3–5 倍。封护选型要点：面漆须耐酸解——氟碳（PVDF/FEVE）与氟乙烯醚类合格，醇酸、丙烯酸脂类会皂化粉化，两年内失光；底漆选渗透型缓蚀底漆而非富锌（锌会与铜形成电偶）。复护周期相应缩短：C4 环境 4–5 年一次面漆，C5-I 2–3 年；施工前先以 pH 试纸检测表面冲洗水的硫酸盐残留，pH < 5.5 须延长清洗。
Under ISO 9223 most industrial atmospheres rank C4–C5-I (SO₂ deposition >80 mg/m²·d), corroding copper 3–5× faster than rural air. Choose acid-resistant topcoats — fluorocarbon (PVDF/FEVE) and fluorovinyl ether grades pass, while alkyds and acrylates saponify and chalk within two years; use penetrating inhibitive primers, never zinc-rich (zinc couples against copper). Shorten recoat cycles accordingly: 4–5 years at C4, 2–3 at C5-I. Before coating, pH-test the final rinse water — below 5.5, sulfate residue remains and washing must continue.