Cov roj hmab ntuj feem ntau yog los ntawm cov roj hmab ntawm tsob ntoo Hevea brasiliensis, uas yog ib hom hauv Brazil tab sis tam sim no feem ntau cog rau hauv cov teb chaws Es Xias Qab Teb xws li Malaysia thiab Indonesia. Thaum cov tawv ntoo raug txiav, cov roj hmab, uas yog cov kua dawb zoo li mis nyuj, yuav tawm los. Cov roj hmab no muaj li ib feem peb ntawm cov dej thiab ib feem peb ntawm cov roj hmab hauv cov tshuaj colloidal. Cov roj hmab no tau tsim nyob rau hauv cov hlwb tsim cov roj hmab tshwj xeeb hu ua laticifers. Cov roj hmab hauv cov roj hmab yog cov polymer ntawm isoprene, nrog rau cov mis tshuaj (C₅H₈)ₙ. Tom qab sau, cov roj hmab yuav raug ua kom cais thiab ua kom cov roj hmab zoo.

Cov roj hmab ua los ntawm cov khoom siv hluavtaws, ntawm qhov tod tes, yog tib neeg tsim los ntawm cov chaw tsim tshuaj lom neeg. Petrochemicals ua haujlwm ua cov khoom pib. Piv txwv li, neoprene (polychloroprene) yog ua los ntawm kev sib xyaw acetylene thiab hydrochloric acid. Emulsion styrene - butadiene roj hmab (E - SBR), siv dav hauv cov log tsheb, yog lwm yam khoom siv hluavtaws. Cov txheej txheem no suav nrog cov tshuaj tiv thaiv polymerization hauv qab cov xwm txheej tshwj xeeb los tsim cov polymers nrog cov khoom zoo li roj hmab, uas tom qab ntawd ua tiav rau hauv cov khoom me me.

Ntxiv rau cov roj hmab tshiab uas tsis tau siv dua tshiab, cov roj hmab rov ua dua tshiab kuj yog qhov tseem ceeb ntawm cov khoom siv roj hmab. Cov khoom pov tseg xws li cov log tsheb siv lawm, cov hauv paus roj hmab, thiab lwm yam khoom siv roj hmab raug sau. Lawv raug txiav ua tej daim me me, sib tsoo, thiab ua kom tau cov khoom siv roj hmab.