Promjena mehani kih svojstava procesom starenja polimernih tkanina otpornih na cijepanje i trganje* / Effect of Aging on Mechanical Properties of Polymeric Ripstop Fabrics

Polimerne tkanine otporne na cijepanje i trganje* (e. ripstop) esto seupotrebljavaju u vanjskim uvjetima. Njihova osjetljivost na atmosferske uvjete va an je faktor pri izboru tkanine odgovaraju ega sirovinskog sastava. U ovom radu tkanine otporne na cijepanje i trganje izlo ene su djelovanju umjetnih atmosferskih uvjeta, a njihova mehani ka svojstva analizirana su prije i nakon izlaganja 1 000 sati ubrzanom starenju radi odre ivanja nastalih promjena. Ispitane su tri vrste tkanine. Ispitane tkanine na injene su od poliamidnog vlakna prevu enog elastoplastomernim poliuretanom, poliamidnog vlakna prevu enog elastoplastomernim poliuretanom i metaliziranog aluminijem te poliesterskog vlakna prevu enog polikarbonatom. Mehani ka svojstva izravno ovise o vrsti materijala i stupnju starenja, me utim iz rasteznih ispitivanja (i) ilavosti udarnim optere enjem i (ii) rastezne vrsto e sporim prirastom sile proizlazi da sni avanje mehani kih svojstava ovisi i o brzini ispitivanja. Taj zaklju ak va an je pri odabiru parametara za izbor materijala izlo enoga u vanjskim uvjetima. / Ripstop fabrics are commonly used for outdoor applications. Their sensitivity to atmospheric conditions is an important issue for materials selection. In this paper different ripstop materials have been exposed to artificial weathering conditions and their mechanical properties have been tested before and after 1,000 hours of accelerated weathering. Three different types of fabrics have been examined. Woven fabrics were made of (i) ripstop polyamide coated with thermoplastic polyurethane, (ii) ripstop polyamide coated with polyurethane and aluminum and (iii) polycarbonate-coated ripstop polyester. Mechanical properties are directly influenced by the type of fabrics and aging degree, but impact tensile tests and tensile tests with low force rate show that the deterioration of mechanical properties depends on testing velocity as well. This conclusion is an important issue for materials selection for outdoor applications.