Raws li cov kws paub txog cov khoom siv hauv tsev, cov kav dej uas tsim hauv Suav teb yog xws li polyethylene kav (PE), polypropylene kav (PP), polybutylene kav (PB) thiab txhuas yas txhuas (PAP). Ntau tshaj 80% ntawm cov kav dej no siv. Lub tsev tu dej thiab cua sov. Piv rau lwm cov kav dej yas, nws yog tsim rau hauv tsev me me-cov kav dej, hluav taws xob cua sov thiab cua sov hauv tsev, cov thawv sab hauv tsev, thiab lwm yam. Ua ntej 1997, kev siv cov kav dej yas txhuas yog nqaim thiab cov zis me me, thiab muaj ob peb muag hauv khw.
Txawm li cas los xij, txij li xyoo 1997, Ministry of Construction tau txwv txoj kev siv cov kav dej hauv cov tsev tshiab. Nws raug nquahu kom siv cov kav dej tshiab xws li cov kav hlau, cov kav hlau polypropylene, cov kav dej polybutene thiab cov kav hlau yas txhuas. Yog li ntawd, cov yeeb nkab ua lag luam yog yam ua haujlwm. Ntau yam khoom muag thiab kev muag khoom muaj kev tu ncua, thiab qee yam muaj qe me me, ua qhov kev loj hlob tshiab rau kev ua lag luam hauv lub teb chaws thiab ua qhov chaw kub. Qhov no tau tso lub hauv paus ruaj khov rau kev tswj hwm kev noj qab haus huv ntawm "ntshav leeg" ntawm chav tsev nyob. Raws li kev tshawb fawb ntawm kev ua lag luam, cov zis ntawm cov kav dej no nce mus txog ob xyoo sib law lias los ntawm 2002 txog 2003, thiab tau mus txog ntau dua 3 lab tons. Nws yuav tsum tau tshaj li ntawm 3,5 lab tons rau xyoo no.
Raws li kev tshawb fawb ntawm kev ua lag luam, tom qab xyoo 1997, vim muaj cov lus teb rau cov yeeb nkab ntsuab, cov khoom ntawm cov khoom siv no muaj kev ua haujlwm zoo, thiab cov khw muag khoom tau ua ntau thiab tsis khov tsis tau, ua rau muaj kev zoo thiab txo qis, nqi. Txawm li cas los xij, tom qab ob peb xyoos ntawm kev sib tw ua lag luam thiab kev lag luam ua lag luam, qee cov khoom me me uas tsis muaj cov khoom lag luam, cov khoom me me, cov khoom me me, thiab tsis tshua zoo tau raug rho tawm hauv kev ua lag luam, thiab cov neeg sib tw tshiab muaj ntau txoj hauv kev nkag mus. Nws pom zoo tias kev lag luam ntawm cov kav dej polyethylene, kav dej polypropylene, cov kav dej thiab cov txhuas yas yuav ua kom muaj txoj kev loj hlob zoo nyob hauv ob peb xyoos tom ntej no. Kangyu yeeb kev lag luam yog niaj hnub tsim lag luam kev sib txuas, kev tshawb nrhiav thiab kev tsim kho, kev tsim khoom, kev muag khoom thiab kev pabcuam. Nrog cov tswv yim zoo tshaj, kev tshawb fawb thiab kev loj hlob muaj zog, cov cuab yeej tsim tawm zoo tshaj plaws thiab kev lag luam zoo heev, lub tuam txhab tau los ua lub hnub qub ci ntsa iab hauv kev lag luam.
