I-PET strap (i-polyester strap) iyona nto ikhethwayo yokuthunyelwa kwexesha elide ngenxa yokugcinwa kwayo okuphezulu. Inzululwazi emva kwalo msebenzi ilele kulwakhiwo lwemolekyuli yepolyester kunye neempawu zayo zokubuyiswa kwe-elastic. Ngokungafaniyo nentsimbi, elahlekelwa yingcinezelo emva kokuba imithwalo ihleli, okanye i-PP, enokuthi iphumle phantsi koxinzelelo oluzinzileyo, i-PET igcina ukunyanzeliswa rhoqo kulo lonke uhambo. Eli nqaku livavanya inzululwazi yezinto ezibambekayo zogcino, kubandakanywa indlela ukuqhelaniswa nemolekyuli, ukubuyiswa kobude, kunye neemeko zobushushu ezichaphazela ukhuseleko lomthwalo ngexesha lokuhamba okwandisiweyo.