Txawm hais tias cov cwj mem nruab nrab yog nyob rau tib qeb ntawm cov cwj mem, lawv cov qauv kev sau ntawv, tus cwj mem lub taub hau, thiab kev siv thev naus laus zis zoo ib yam li cov roj ib txwm siv -cov cwj mem ballpoint. Kev tshawb fawb thiab kev loj hlob ntawm tus cwj mem nruab nrab yog qhov nyuaj dua. Nyob rau hauv lub ntiaj teb no, Nyiv, Tebchaws Meskas, Lub Tebchaws Yelemees, Kaus Lim Qab Teb thiab lwm lub tebchaws tsim cov cwj mem tsis zoo, thiab Nyiv yog qhov zoo tshaj plaws. Tus yuam sij rau kev tshawb fawb thiab kev loj hlob ntawm tus cwj mem nruab nrab yog: tus qauv ntawm tus number case; cov txheej txheem txheej txheem sib piv cov qauv; kev sib piv ntawm tus cwj mem thiab tus cwj mem taub hau.
Ua ntej tshaj plaws, hauv kev tsim cov qauv, nws yog ib qho tsim nyog yuav tsum ua kom tus number case muaj qhov tsim nyog viscosity, ntom ntom ntom, pH tus nqi, tsis yog tsuas yog xyuas kom meej tias tus cwj mem yog du thiab tsis to, tab sis kuj yuav tsum xyuas kom meej tias tus number case yog lub teeb. -resistant, dej-resistant, tshav kub-resistant, txias-resistant, moisturizing, thiab permeability. Txhawm rau daws qhov ruaj khov ntawm tus number case, tus number case yuav tsis deteriorate tom qab lub sijhawm ntev ntawm kev cia, thiab yuav tsis muaj delamination thiab nag lossis daus. Nws tseem yuav tsum tau ua kom muaj kev nyab xeeb ntawm tus number case, tsis yog - tshuaj lom thiab tsis yog - corrosive.
