Cov yam ntxwv ntawm cov khoom siv roj hmab

Nws yog cov roj hmab sib xyaw ua los ntawm cov khoom siv roj hmab tom qab sib xyaw nrog cov khoom siv sab hauv ua cov khoom siv raw. Thaum lub sij hawm sib xyaw roj hmab, cov mis yog tsim raws li cov yam ntxwv ntawm cov khoom siv roj hmab uas yuav tsum tau ua, thiab cov khoom yuav tsum tau ua hardness yog txiav txim siab. Cov khoom yog tsim thiab molded los ntawm cov roj hmab ca vulcanizing tshuab. Tom qab cov khoom tsim, kev kho flashing yog thaum kawg ua kom cov khoom nto du thiab tsis muaj burrs.