Kev sib piv ntawm Polyethylene Yas thiab Polypropylene Yas
Yas tau dhau los ua ib feem tseem ceeb ntawm lub neej niaj hnub no vim nws lub cev tsis hnyav, ruaj khov, thiab yooj yim hloov pauv. Ntawm ntau hom yas uas muaj nyob hauv khw, polyethylene (PE) thiab polypropylene (PP) yog ob hom siv ntau tshaj plaws. Ob leeg koom nrog tsev neeg polyolefin, uas yog cov yas uas muaj cov pa roj carbon thiab hydrogen ua ke. Txawm hais tias lawv zoo li zoo sib xws thaum xub thawj siab, PE thiab PP muaj qhov sib txawv tseem ceeb hauv lawv cov qauv tshuaj lom neeg, cov yam ntxwv ntawm lub cev, kev tiv taus cua sov, thiab txawm tias kev siv txhua hnub. Tsab xov xwm no piv ob qho no los pab peb nkag siab txog lawv cov txiaj ntsig, kev txwv, thiab kev siv tsim nyog.
1. Lub Ntsiab Lus thiab Cov Qauv Tseem Ceeb
Polyethylene (PE) yog ib hom yas uas tsim los ntawm kev sib xyaw ua ke ntawm monomer ethylene (C₂H₄). Cov qauv ntawm PE yooj yim heev: ib txoj saw ntev ntawm cov pa roj carbon atoms nrog cov hydrogen atoms txuas nrog cov saw. PE muaj ntau hom tseem ceeb, xws li LDPE (Low Density Polyethylene) uas yooj ywm dua thiab HDPE (High Density Polyethylene) uas tawv dua thiab muaj zog dua. Qhov sib txawv ntawm qhov ceev no yog cuam tshuam los ntawm qib ntawm kev sib txuas ntawm cov saw polymer.
Lub caij no, polypropylene (PP) yog tsim los ntawm monomer propylene (C₃H₆). Qhov sib txawv tseem ceeb yog qhov muaj cov pab pawg methyl (-CH₃) txuas rau cov saw hlau tseem ceeb. Cov pab pawg methyl no ua rau PP feem ntau tawv dua PE thiab muab nws cov yam ntxwv sib txawv, tshwj xeeb tshaj yog hais txog lub zog kho tshuab thiab kev tiv taus kub siab.
2. Cov Khoom Siv Lub Cev: Kev Yoog Tau, Kev Ruaj Khov, thiab Kev Zoo Nkauj
Hais txog kev yooj ywm, PE—tshwj xeeb tshaj yog LDPE—zoo dua. LDPE zoo li mos dua, feem ntau yuav ywj dua, thiab yooj yim khoov yam tsis tawg. Qhov no yog vim li cas LDPE thiaj siv dav rau cov hnab yas, yas qhwv, thiab cov ntim khoom yooj ywm. HDPE yeej tawv dua LDPE, tab sis tseem muaj qee yam "ywj" piv rau PP.
Qhov sib piv, PP muaj qib siab dua ntawm kev tawv. Cov khoom ua los ntawm PP, xws li qee cov thawv ntim khoom noj, cov straw, lossis cov khoom siv hauv tsev, feem ntau zoo li tawv dua thaum tseem sib dua. PP kuj paub txog nws qhov kev tiv taus kev qaug zog zoo, ua rau nws tsim nyog rau cov khoom nrog cov pob qhov rooj uas muaj sia nyob, xws li lub hau fwj lossis cov thawv cia khoom nrog cov pob qhov rooj uas feem ntau qhib thiab kaw.
Hais txog qhov tsos, ob qho tib si tuaj yeem ua pob tshab lossis tsis pom tseeb nyob ntawm cov qauv thiab cov txheej txheem tsim khoom, tab sis feem ntau PP yooj yim dua los ua kom zoo nkauj thiab zoo nkauj, thaum PE (tshwj xeeb tshaj yog LDPE) feem ntau zoo li "mos dua" thiab me ntsis pos huab nyob ntawm qhov tuab.
3. Kev Tiv Thaiv Kub thiab Melting Point
Ib qho ntawm qhov sib txawv tseem ceeb tshaj plaws yog kev tiv taus cua sov. PP feem ntau muaj qhov kub siab dua (kwv yees li 160–170 ° C) dua li ntau hom PE. HDPE feem ntau muaj qhov kub siab li 130 ° C, thaum LDPE qis dua (kwv yees li 105–115 ° C). Yog li ntawd, PP zoo dua rau cov ntawv thov uas xav tau kev tiv taus cua sov, xws li cov thawv ntim khoom noj uas siv tau rau cov khoom noj kub lossis qee yam khoom uas muaj kev nyab xeeb rau cov xwm txheej cua sov tshwj xeeb (txawm hais tias koj tseem yuav tsum ua raws li daim ntawv lo ntawm tus neeg tsim khoom).
Hauv kev siv txhua hnub, PP feem ntau raug xaiv rau cov thawv ntim khoom noj, vim nws tiv taus cua sov ntau dua thiab yuav tsis yooj yim khoov thaum raug rau qhov kub siab. PE, tshwj xeeb tshaj yog LDPE, yooj yim dua rau kev hloov pauv thaum raug rau qhov kub siab, yog li nws feem ntau siv rau kev ntim khoom txias lossis kev siv ib zaug xwb nrog kev raug cua sov tsawg kawg nkaus.
4. Kev Tiv Thaiv Tshuaj thiab Dej noo
Ob qho tib si PE thiab PP paub txog lawv cov tshuaj lom neeg zoo heev, tshwj xeeb tshaj yog rau dej thiab ntau yam tshuaj lom neeg tsis muaj zog. Ob qho tib si kuj yog hydrophobic, txhais tau tias lawv tsis nqus dej yooj yim. Qhov no ua rau lawv zoo tagnrho rau kev ntim khoom noj, lub raj mis, thiab txawm tias cov txheej.
Txawm li cas los xij, nyob rau hauv qee qhov xwm txheej, PP yuav ua rau muaj kev tiv taus zoo dua me ntsis rau qhov kub siab thaum sib cuag nrog cov tshuaj lom neeg. PE kuj tseem tiv taus ntau yam tshuaj lom neeg, tab sis nws cov qauv tiv taus tuaj yeem sib txawv nyob ntawm hom (LDPE vs. HDPE) thiab cov xwm txheej ib puag ncig.
5. Lub Zog Kho Tshuab thiab Kev Ruaj Khoov
Hais txog lub zog tensile, HDPE thiab PP ob leeg muaj zog, tab sis lawv cov yam ntxwv lub zog sib txawv. PP feem ntau muaj lub zog tensile thiab stiffness ntau dua, thaum PE feem ntau "ductile" thiab tiv taus kev cuam tshuam, tshwj xeeb tshaj yog thaum kub qis. PE, tshwj xeeb tshaj yog HDPE, feem ntau zoo tshaj plaws hauv kev tiv taus kev cuam tshuam thiab tsis tshua muaj kev tawg, ua rau nws siv dav rau cov kaus poom jerry, lub raj mis ntxuav khaub ncaws, cov kav dej, thiab cov thawv.
PP muaj qhov zoo ntawm kev tiv taus cov khoom siv qaug zog, yog li cov khoom uas txav mus los tas li (xws li cov yas pob qhov rooj) zoo dua rau kev siv PP dua li PE.
6. Cov Kev Siv Hauv Lub Neej Txhua Hnub
Cov kev sib txawv ntawm cov khoom no ua rau PE thiab PP muaj cov chaw siv sib txawv.
Piv txwv ntawm kev siv polyethylene (PE):
- Cov hnab yas rau kev yuav khoom (LDPE/HDPE)
- Yas qhwv thiab zaj duab xis ntim khoom (LDPE)
- Lub raj mis thiab cov kaus poom jerry (HDPE)
– Tej cov kav dej thiab cov kav roj (HDPE)
- Cov khoom ua si thiab ntau yam khoom siv hauv tsev uas xav tau kev tiv thaiv kev cuam tshuam
Piv txwv ntawm kev siv polypropylene (PP):
- Cov thawv ntim khoom noj thiab cov thawv ntim khoom noj (feem ntau yog rau cov khoom noj kub)
- Lub hau raj mis nrog lub pob khawm muaj sia nyob
- Cov pas nrig, qee cov diav yas
– Cov hnab yas (woven PP) rau mov, chiv, lossis cov khoom siv hauv tsev
- Qee cov khoom siv hauv tsheb thiab sab hauv uas tsis hnyav vim lawv muaj zog tab sis tsis hnyav
7. Kev Siv Dua thiab Kev Cuam Tshuam Rau Ib Puag Ncig
Los ntawm kev pom ntawm kev siv dua tshiab, PE thiab PP yog cov yas uas siv ntau heev rau kev siv dua tshiab, txawm hais tias qhov ua tiav ntawm kev siv dua tshiab nyob ntawm thaj chaw tswj cov khib nyiab. Cov cai siv dua tshiab feem ntau suav nrog:
– HDPE yog coded 2
- LDPE tau muab tus lej 4
– PP tau muab code 5
Feem ntau, HDPE feem ntau yog ib hom yas muaj nqis tshaj plaws los siv dua vim nws muaj ntau thiab siv rau hauv cov ntim tuab. PP kuj tseem siv dua ntau dua, tab sis qee qhov chaw cov khoom siv tsis ruaj khov npaum li PE.
Nyob rau hauv ib puag ncig, ob qho tib si ntsib tib qho teeb meem: lawv nyuaj rau lwj yog tias pov tseg tsis saib xyuas. Yog li ntawd, kev siv zog los txo kev siv cov yas siv ib zaug xwb, cais cov khib nyiab, thiab nce kev rov ua dua tshiab yog qhov tseem ceeb heev. Kev xaiv ntawm PE thiab PP tsis txhais tau tias yuav txo qhov cuam tshuam rau ib puag ncig; qhov tseem ceeb dua yog kev tsim khoom, lub neej ntev, thiab cov txheej txheem tswj cov khib nyiab.
8. Txoj kev
Polyethylene (PE) thiab polypropylene (PP) yog cov yas uas siv tau ntau yam, txhua yam muaj nws qhov zoo. PE zoo heev hauv kev yooj ywm thiab kev tiv taus kev cuam tshuam, tshwj xeeb tshaj yog hauv kev siv xws li cov ntim khoom sib dua mus rau cov thawv ruaj khov xws li cov kaus poom thiab cov kav dej. Lub caij no, PP zoo heev hauv kev ruaj khov, tiv taus cua sov, thiab tiv taus kev qaug zog, ua rau nws zoo tagnrho rau cov thawv zaub mov tiv taus cua sov thiab cov khoom lag luam nrog cov pob qhov rooj lossis siv ntau zaus.
Kev nkag siab txog qhov txawv ntawm ob qho no pab peb xaiv cov khoom siv zoo rau peb cov kev xav tau, txawm tias siv rau kev lag luam lossis hauv tsev. Thaum kawg, kev siv yas zoo thiab kev tswj cov khib nyiab kom zoo tseem yog qhov tseem ceeb rau kev txo cov teeb meem tsis zoo rau ib puag ncig, txawm tias yog hom polymer twg los xij.
