Qhov Tseem Ceeb - HDPE vs LDPE
Txawm tias HDPE thiab LDPE yog ob pawg ntawm Polyethylene, qee qhov sib txawv tuaj yeem pom ntawm lawv raws li lawv cov khoom siv kho tshuab. Polyethylene yog ib tug sib tov ntawm cov organic tebchaw zoo sib xws uas muaj cov tshuaj formula ntawm (C2H4)n Polyethylene yog categorized rau hauv ntau pawg sib txawv raws li nws qhov ntom ntom thiab branching. Hais txog kev xav tau thiab kev muab khoom, cov qib polyethylene tseem ceeb tshaj plaws yog HDPE thiab LDPE. High-density Polyethylene (HDPE) thiab Low-density Polyethylene (LDPE) muaj cov khoom sib txawv xws li cov qauv siv lead ua, qhov loj thiab qhov xwm txheej ntawm cov ceg thiab qhov hnyav molecular. Hauv lwm lo lus, HDPE thiab LDPE raug suav tias yog qhov sib txawv ntawm cov ntawv thov plastics spectrum. Qhov sib txawv tseem ceeb ntawm HDPE thiab LDPE yog qhov ntom ntom lossis cov yam ntxwv ntawm cov polymer molecules sib dhos. HDPE polymers yog ncaj thiab sib zog ua ke thaum LDPE polymers muaj ntau ceg, thiab lawv tsis nyob ze. Raws li cov qauv molecular txhua hom yas muaj nws tus kheej lub cev thiab tshuaj lom neeg yam ntxwv. Hauv tsab xov xwm no, cia peb piav qhia seb qhov txawv ntawm HDPE thiab LDPE yog dab tsi.
High Density Polyethylene (HDPE) yog dab tsi?
HDPE tau txhais tau zoo los ntawm qhov ceev ntawm qhov loj dua lossis sib npaug ntawm 0.941 g / cm 3 Nws muaj cov txheej txheem polymer thiab qis dua ntawm cov ceg. Qhov no ua rau cov molecules yuav tsum tau ntim los ze zog thiab cov ntawv cog lus sib txuas muaj zog dua li hauv cov ceg ntoo zoo li LDPE. Qhov uas tsis muaj ceg kuj tshwm sim hauv kev ceev dua thiab qee yam khoom siv ntau dua ua rau muaj LDPE. Nrog lub zog tensile siab, HDPE yog siv rau hauv cov khoom xws li cov thawv khib nyiab, cov khoom ua si menyuam yaus, cov kav dej, cov jugs thiab jars nrog rau cov ntim khoom xws li mis nyuj jugs, butter tubs, thiab cov tshuaj ntxuav tais diav. HDPE kuj tseem muaj zog dua thiab opaque ntau dua thiab tuaj yeem tiv taus qhov kub siab dua feem ntau piv rau LDPE. Industrially, HDPE yog synthesized los ntawm ethylene los ntawm cov txheej txheem catalytic.
Dab tsi yog Qhov Tsawg Tsawg Polyethylene (LDPE)?
LDPE yog txhais tau zoo los ntawm qhov ntom ntom ntawm 0.91–0.94g / cm 3 Ib ceg polymer, LDPE yog tsim los ntawm ethylene los ntawm cov txheej txheem catalytic. Qhov ntau branching xwm tshwm sim nyob rau hauv molecules packing irregularly thiab intermolecular bonds tsis muaj zog tshaj nyob rau hauv high linear polymers xws li HDPE. Nrog lub zog tensile tsawg, LDPE yog siv rau hauv cov khoom xws li hnab yas thiab zaj duab xis qhwv nrog rau cov ntim khoom xws li lub raj mis dej, cov thawv ntim khoom noj, lub raj mis thiab cov raj yas. LDPE kuj hloov tau yooj yim dua thiab pob tshab thiab tsis tuaj yeem tiv taus qhov kub thiab txias ntau dua piv rau HDPE.
Qhov txawv ntawm HDPE thiab LDPE yog dab tsi?
HDPE thiab LDPE tuaj yeem muaj qhov sib txawv ntawm lub cev thiab kev ua haujlwm. Cov no tuaj yeem muab faib ua pawg hauv qab no,
Polymer Resin Abbreviation
HDPE: HDPE yog High density polyethylene
LDPE: LDPE yog Tsawg ntom polyethylene
Structure (Nyob ntawm ceg)
HDPE: Nws muaj cov qauv linear. Yog li ntawd, nws tuaj yeem compressed, thiab nws tsis yooj yim dua thiab muaj zog dua (Daim duab 1)
LDPE: Nws muaj ntau ceg. Yog li ntawd, nws yog ib qho nyuaj rau compress, thiab nws yog lub teeb yuag thiab saj zawg zog (Daim duab 1)
Crystalline thiab Amorphous Regions
HDPE: HDPE muaj cov crystalline siab thiab qis amorphous cheeb tsam (ntau dua 90% crystalline). Nws muaj ob peb sab chains ib 200 carbon atoms nyob rau hauv lub ntsiab carbon skeleton ua rau ntev linear chains. Raws li qhov tshwm sim, kev ntim khoom zoo thiab cov crystallinity siab tuaj yeem pom (Daim duab 1).
LDPE: LDPE muaj cov crystalline tsawg thiab siab amorphous cheeb tsam (tsawg dua 50-60% crystalline). Nws muaj tsawg dua 1 sab saw ntawm 2-4 carbon atoms nyob rau hauv lub ntsiab carbon skeleton ua rau branching. Yog li ntawd, kev ntim khoom tsis tu ncua thiab tsis tshua muaj crystallinity tuaj yeem pom (Daim duab 1).
Tensile Strength thiab Intermolecular Forces
HDPE: HDPE muaj zog intermolecular rog thiab tensile zog dua LDPE. Tensile zog yog 4550 psi.
LDPE: LDPE muaj zog tsis muaj zog thiab lub zog tensile dua HDPE.
Melting Point
HDPE: 135 ° C (siab dua melting point piv rau LDPE)
LDPE: 115 ° C (qis melting point piv rau HDPE)
Plastic resin codes
HDPE: HDPE feem ntau yog rov ua dua tshiab, thiab cov lej cim npe (tseem hu ua cov cim rov ua dua tshiab) yog tus lej 2 (Saib daim duab 2).
LDPE: LDPE feem ntau yog rov ua dua tshiab, thiab cov lej cim npe (tseem hu ua cov cim rov ua dua tshiab) yog tus lej 4 (Saib daim duab 2).
Density
HDPE: Qhov ceev tuaj yeem nyob ntawm 0.95-.97 g / cm3. Qhov ceev yog siab dua li ntawm LDPE.
LDPE: Qhov ceev tuaj yeem nyob ntawm 0.91-0.94 g / cm3. Qhov ceev yog qis dua li HDPE.
Txoj Kev Nyuaj Siab
HDPE: Lub ntiajteb txawj nqus tshwj xeeb yog 0.95. Qhov tshwj xeeb lub ntiajteb txawj nqus yog siab dua li ntawm LDPE.
LDPE: Qhov tshwj xeeb lub ntiajteb txawj nqus yog 0.92. Qhov tshwj xeeb lub ntiajteb txawj nqus yog qis dua HDPE.
tshuaj muaj txiaj ntsig
HDPE: HDPE yog tshuaj lom neeg tsis muaj zog, thiab tiv thaiv ultraviolet rays piv rau LDPE.
LDPE: LDPE tsis tshua muaj tshuaj lom neeg thiab thaum raug lub teeb thiab oxygen ua rau poob lub zog.
Transparency
HDPE: HDPE tsawg dua pob tshab lossis ntau dua opaque dua LDPE.
LDPE: LDPE yog pob tshab lossis tsawg dua opaque dua HDPE.
Txoj Kev
HDPE: Nws muaj zog dua thiab nyuaj dua LDPE.
LDPE: Nws tsis muaj zog thiab tsis muaj zog dua li HDPE.
Kev hloov pauv
HDPE: Nws yog nruj dua li LDPE
LDPE: Nws hloov pauv ntau dua li HDPE
daim ntawv thov dav dav
HDPE: Cov tshuaj zawv plaub hau, cov thawv ntim khoom noj, ntxhua khaub ncaws thiab lub tsev tu lub fwj, cov thawv ntim khoom, mis nyuj, dej, thiab kua txiv hmab txiv ntoo, cov tshuaj ntxuav tais diav, lub hnab ntim khoom noj, cov khoom siv rov qab, cov kav dej
LDPE: hnab rau kev tu kom qhuav thiab ntawv xov xwm, ntsws qhwv, zaj duab xis, squeezable fwj (zib ntab / mustard), hnab khob cij, hnab khib nyiab
Nyob rau hauv qhov xaus, HDPE thiab LDPE yog cov qib sib txawv ntawm polyethylene thiab qhov sib txawv tseem ceeb ntawm lawv yog kev sib haum xeeb ntawm cov polymer molecules. Raws li qhov tshwm sim, lawv yuav muaj cov khoom sib txawv ntawm lub cev thiab cov kev siv sib txawv.
