same such animal fiber materials are prepared using an aqueous finishing process to covalently attach a heterocyclic n halamine to an animal fiber material once prepared the finished animal fiber materials of the present invention have antibacterial activity against pathogenic microorganisms moreover the antibacterial activity of such animal fiber materials can be regenerated by washing with a chlorine containing solution application_number US 79700801 A description the present invention provides a method for preparing regenerable antimicrobial animal fiber materials such materials are prepared in a conventional processing of animal fiber materials comprising acetalization after which a heterocyclic n halamine is added in an aqueous finishing process the animal fiber materials comprise flesh hide and skin wool cloth silk cloth duck down goose down etc the prepared regenerable antimicrobial animal fiber materials according to the present invention comprise leather wool cloth silk cloth duck down goose down etc heterocyclic n halarnine as used in this invention refers to a 4 to 7 membered ring wherein at least 3 members of the ring are carbon and from 1 to 3 members of the ring are nitrogen heteroatom and from 0 to 1 member of the ring is oxygen heteroatom wherein from 0 to 2 carbon members comprise a carbonyl group and wherein at least 1 to 3 nitrogen atoms are substituted with a hydrogen or hydroxyalkyl group such as u2014 ch 2 oh or a alkoxyalkyl group such as u2014 ch 2 och 3 at least one ring nitrogen has bonded thereto a halogen atom in addition the ring members can be further substituted with alkyl groups such as methyl ethyl etc or hydroxy groups 0013 fig1 shows the molecular structures of the two heterocyclic.