Thaum siv, cov log tsheb roj hmab nthuav tawm cov teeb meem xws li kev ua haujlwm luv luv, hnav tsis zoo thiab tsim kua muag, tshwj xeeb tshaj yog cov log tsheb, uas feem ntau ua rau muaj kev sib tsoo vim lawv lub peev xwm thauj khoom tsawg. Tus nqi peev ntawm cov khoom siv roj hmab log tsheb yog siab, thiab qee cov txheej txheem yuav tsum tau ua manually. Txawm tias muaj cov cuab yeej molding siab heev, kev tsim khoom zoo thiab qhov zoo ntawm txhua pawg ntawm cov khoom tsis tuaj yeem ua kom zoo ib yam. Tsis tas li ntawd, cov log tsheb roj hmab yuav tsim cov khoom pov tseg ntau thaum siv, thiab nws nyuaj heev rau kev rov ua dua thiab rov siv dua tom qab lawv tau muab pov tseg, uas yuav ua rau muaj kuab paug ib puag ncig. Polyurethane elastomer yog qhov hnav-tiv taus elastomer tshaj plaws tam sim no. Nws muaj qhov zoo ntawm kev hnav tsis kam, colourability, siab txiav tsis kam, zoo heev roj tsis kam thiab tshuaj tsis kam. Cov log tsheb polyurethane muaj ntau dua li cov log tsheb roj hmab, thiab yuav tsis muaj cov log tsheb ntog tshwm sim. Txiav kub kub.