soft roj hmab
Cov roj hmab vulcanized raw cov roj hmab yog ntxiv nrog sulfur thiab rhuab nyob rau hauv ib tug tej yam siab, uas yuav txhim khu nws elasticity thiab hnav tsis kam, thiab tsis yooj yim cuam tshuam los ntawm kub thiab deteriorate; cov tshuaj tiv thaiv corrosion kuj tseem txhim kho, thiab nws tsis yooj yim rau yaj hauv cov tshuaj zoo tib yam. Txoj kev kho nrog sulfur no hu ua vulcanization, thiab cov roj hmab vulcanized hu ua cov roj hmab mos.