xov xwm

Polyolefins yog dab tsi?

Polyolefins yog tsev neeg ntawm polyethylene thiab polypropylene thermoplastics.Lawv yog tsim los ntawm cov roj thiab cov nkev ntuj los ntawm cov txheej txheem ntawm polymerization ntawm ethylene thiab propylene feem.Lawv versatility tau ua rau lawv yog ib qho ntawm cov yas nrov tshaj plaws hauv kev siv niaj hnub no.

Cov khoom ntawm polyolefins

Muaj plaub hom polyolefins:

• LDPE (low-density polyethylene): LDPE yog txhais los ntawm qhov ceev ntawm 0.910-0.940 g / cm3.Nws tuaj yeem tiv taus qhov kub ntawm 80 ° C tsis tu ncua thiab 95 ° C rau lub sijhawm luv luv.Ua nyob rau hauv translucent los yog opaque variations, nws yog heev saj zawg zog thiab tawv.
• LLDPE (linear low-density polyethylene): yog ib txoj kab uas muaj polyethylene, nrog rau cov ceg luv luv, feem ntau ua los ntawm copolymerization ntawm ethylene nrog cov saw ntev olefins.LLDPE muaj lub zog tensile siab dua thiab muaj kev cuam tshuam ntau dua thiab kev ua haujlwm hnyav dua li LDPE.Nws yog yooj yim heev thiab elongates nyob rau hauv kev ntxhov siab.Nws tuaj yeem siv los ua cov yeeb yaj kiab thinner thiab muaj cov tshuaj tiv thaiv zoo.Nws muaj cov khoom hluav taws xob zoo.Txawm li cas los xij, nws tsis yooj yim ua raws li LDPE.
• HDPE (high-density polyethylene): HDPE paub txog nws qhov loj zog-rau-qhov sib piv.Qhov ceev ntawm HDPE tuaj yeem nyob ntawm 0.93 txog 0.97 g / cm3 lossis 970 kg / m3.Txawm hais tias qhov ceev ntawm HDPE tsuas yog marginally siab dua li ntawm tsawg-density polyethylene, HDPE muaj me ntsis branching, muab nws muaj zog intermolecular rog thiab tensile zog tshaj LDPE.Nws kuj yog ib qho nyuaj thiab ntau opaque thiab tuaj yeem tiv taus qhov kub thiab txias (120 ° C rau lub sijhawm luv).
• PP (polypropylene): Qhov ceev ntawm PP yog nyob nruab nrab ntawm 0.895 thiab 0.92 g / cm³.Yog li, PP yog cov khoom siv yas nrog qhov ntom ntom.Piv rau polyethylene (PE) nws muaj cov khoom siv zoo tshaj plaws thiab kev ua haujlwm thermal, tab sis tsis muaj tshuaj lom neeg tsawg.PP feem ntau yog tawv thiab hloov tau, tshwj xeeb tshaj yog thaum copolymerised nrog ethylene.

Kev siv ntawm polyolefins

Cov yam ntxwv tshwj xeeb ntawm ntau hom polyolefins qiv lawv tus kheej rau kev siv sib txawv, xws li:

• LDPE: cling zaj duab xis, nqa hnab, ua liaj ua teb zaj duab xis, mis nyuj coatings, hluav taws xob cable txheej, hnyav hnyav industrial hnab.
• LLDPE: ncab zaj duab xis, ntim zaj duab xis, ntim cov thawv ntim, thiab cov khoom hnyav, nruab nrab thiab cov hnab me me.
• HDPE: crates thiab thawv, fwj (rau cov khoom noj khoom haus, detergents, tshuaj pleev ib ce), ntim khoom noj, khoom ua si, petrol tank, industrial wrapping thiab zaj duab xis, kav dej thiab khoom siv hauv tsev.
• PP: ntim khoom noj, suav nrog yogurt, margarine lauj kaub, qab zib thiab khoom noj txom ncauj wrappers, microwave-pov thawj thawv, ntaub pua plag fibers, vaj rooj tog, ntim kho mob thiab cov khoom siv, nra, cov khoom siv hauv chav ua noj, thiab cov kav dej.