6641 Ko te kiriata polyester/polyester ko te reinga ngawari kore-whatu (Class F DMD) he pepa whakamaarama hiato e toru nga papahanga i hangaia mai i te kiriata polyester rewa teitei me te papanga kore-whatu wera-roke wera. Ko ia taha o te kiriata polyester (M) ka herea e tetahi paparanga polyester papanga kore-whatu (D) me te whakapiri Class F. Ko te akomanga waiariki ko te akomanga F, Kei te kiia hoki ko te 6641 F akomanga DMD ranei Class F DMD pepa whakamaarama.