Ua ntej rov siv cov yas pov tseg siv ntau txoj kev rov ua dua tshiab, kev txheeb xyuas feem ntau tsim nyog. Vim muaj ntau haiv neeg thiab txoj hauv kev ntawm kev noj cov yas, thiab qhov nyuaj ntawm kev sib txawv yooj yim tshaj tawm - cov khoom siv plastics los ntawm cov tsos, nws yog qhov zoo tshaj plaws los sau cov khoom yas nrog lawv cov khoom siv. Tuam Tshoj tau tsim GB/T16288-1996 "Recycling Marking for Plastic Packaging Products," referencing the material type marking proposed and implemented by the Society of Plastics Engineers (SPE) in United States. Thaum txoj kev kos npe no yooj yim rau kev txheeb xyuas, ntau cov khoom siv yas tsis muaj cim nyob hauv Suav teb tseem muaj teeb meem kev txheeb xyuas. Txhawm rau cais cov plastics sib txawv rau kev rov ua dua tshiab, nws yog ib qho tseem ceeb kom nkag siab ua ntej kom paub txog cov yas sib txawv. Cov hauv qab no yog ib txoj hauv kev yooj yim rau kev txheeb xyuas cov yas:
Cov tsos mob: Los ntawm kev soj ntsuam cov tsos ntawm cov yas, ib tug yuav pib txheeb xyuas nws cov qeb: thermoplastic, thermosetting, los yog elastomer. Feem ntau, cov thermoplastics muab faib ua crystalline thiab amorphous hom. Crystalline plastics zoo li translucent, milky, lossis opaque, tsuas yog ua pob tshab hauv lub xeev nyias nyias, nrog cov tawv tawv xws li muag muag mus rau horny. Amorphous plastics feem ntau tsis muaj xim thiab pob tshab tsis muaj tshuaj ntxiv, nrog rau qhov nyuaj ntawm qhov hnyav dua li lub horn-zoo li roj hmab (qhov twg plasticizers thiab lwm yam khoom siv feem ntau ntxiv). Thermosetting plastics feem ntau muaj cov fillers thiab opaque; lawv yog pob tshab yog tias lawv tsis muaj cov fillers. Elastomers muaj ib tug rubbery xav thiab ib co℃ntawm elongation.
Cov yam ntxwv cua sov: Cov yam ntxwv cua sov ntawm peb hom yas saum toj no kuj txawv thiab tuaj yeem txheeb xyuas los ntawm cua sov. Cov thermoplastics soften thaum rhuab, yaj yooj yim, thiab ua pob tshab thaum molten, feem ntau tuaj yeem rub mus rau hauv cov xov los ntawm cov yaj, thiab feem ntau yooj yim rau cua sov- foob. Thermosetting plastics tswj lawv cov qub hardness thiab tsis soften ua ntej tshuaj decomposition, seem seem seem ruaj khov kom txog thaum carbonization ntawm decomposition kub. Elastomers tsis ntws thaum rhuab kom txog thaum lawv cov tshuaj decomposition kub, thaum lub sij hawm cov khoom decomposes thiab carbonizes.
