1. Raws li cov duab ntawm lub hnab lim, nws tuaj yeem muab faib ua lub hnab tiaj tus (trapezoidal thiab tiaj tus) thiab lub hnab ncig (cylindrical).
2. Raws li txoj hauv kev nkag thiab qhov hluav taws xob, nws tuaj yeem muab faib ua: qhov hluav taws xob sab hauv thiab sab sauv sab saud, sab sauv sab hauv thiab sab nraud, thiab DC hom (tsuas yog lub hnab tiaj tus).
3. Raws li txoj kev pom ntawm lub hnab, nws tuaj yeem muab faib ua sab nraud pom thiab sab hauv pom.
Cov fibers siv rau lim xov xwm muaj xws li paj rwb fibers, wool fibers, hluavtaws fibers, thiab iav fibers. Lim xov xwm woven los ntawm cov fibers sib txawv muaj cov khoom sib txawv. Cov ntaub ntawv lim siv feem ntau suav nrog 208 lossis 901 polyester log velvet daim ntaub, nrog kev siv kub feem ntau tsis tshaj 120 degree. Cov iav fiber ntau lim hnab kho nrog silicone resin feem ntau muaj kev siv kub tsis tshaj 250 degree, thiab paj rwb ntaub ntaub feem ntau haum rau kev siv tsis muaj corrosive; Plua plav muaj roj nrog qhov kub thiab txias qis dua 80-90 degree .
