摘要 |
Engineered composite coated flat-rolled steel strip is produced in continuous line operations, in which flat-rolled steel strip, free of surface iron oxide, having a metallic corrosion-protective coating, is polymer coated in continuous-line operations in which a plurality of adherent thin-film layers of polymeric material are deposited on a strip surface. In a dual-surface polymeric coating embodiment, each surface is separately-pretreated for surface adhesion, solidified, and polymeric overhang is removed. Finish processing re-melts the polymer coating and rapidly cools that coating through glass-transition temperature to establish amorphous characteristics in the polymeric coating materials. An anhydride-modified polypropylene, first contacts the strip, an intermediate layer can include about fifteen to twenty five percent, by weight, polybutylene with the balance polypropylene; an outer surface polymeric layer includes about five to ten percent, by weight, polybutylene with the balance polypropylene.
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