Ukhe wazifumana ujonge kwiimveliso zeplastiki kwaye uzibuza, “Yintoni intsebenziswano nge-LDPE kunye ne-HDPE?” Ungakhathazeki, awuwedwa. Ezi inkwenkwezi zimbini zeplastiki, i-Low-Density Polyethylene (LDPE) kunye ne-High-Density Polyethylene (HDPE), zikuyo yonke indawo ojonga kuyo, ukusuka kwingxowa yakho yeplastiki ethembekileyo ukuya kwimibhobho yamanzi egcina iishawari zakho zibaleka.
Kwesi sikhokelo silula, sintywila nzulu kwi-LDPE kunye ne-HDPE. Yicinge njengencoko yobuhlobo malunga nabazala beplastiki abanokubonakala ngokufanayo kodwa babe neemfihlo ezinomdla kwimikhono yabo yepolymer. Siza kuvula iimfihlelo zeendlela zabo zemolekyuli, sithethe ngeempawu zabo zomzimba nezekhemikhali, sichithe iimbotyi ngendlela ezenziwe ngayo, kwaye sijonge phambili ukuze sifumanise ukuba bajinga phi na kakhulu.
Ke, ukuba ukhe wafuna ukwazi ukuba yintoni eyenza ezi plastiki ziphawule kwaye kutheni zibalulekile, hlala ujikeleze. Ngexesha sigqibile, uya kuba ngumhlali omkhulu weplastiki phakathi kwabahlobo bakho. Masiqalise kolu hambo lweplastiki kwaye sityhile ihlabathi elinomdla le-LDPE vs. HDPE!
Ukuqulunqwa kunye noLwakhiwo lweMolekyuli
Ukuqonda ukungafani phakathi kwe-LDPE kunye ne-HDPE, kunyanzelekile ukuba uqale ngezinto ezisisiseko: ukubunjwa kwazo kunye nokwakheka kweemolekyuli.
| Ipropati | I-LDPE (iPolyethylene yoXinano oluphantsi) | I-HDPE (iPolyethylene yoXinano oluPhezulu) |
|---|---|---|
| Inkqubo yePolymerization | I-polymerization enkulu | Ziegler-Natta polymerization |
| Ulwakhiwo lweemolekyuli | Inesebe | Umgca |
| Ubuninzi (g/cm³) | 0.91 – 0.94 | 0.94 – 0.97 |
| Ukuba bhetyebhetye | Ubhetyebhetye kakhulu | I-flexible encinci, iqinile |
I-LDPE: I-LDPE yenziwe nge-radical polymerization, ekhokelela kwisakhiwo semolekyuli esibonakaliswe nge-branching kunye nobuninzi obuphantsi. I-branching ye-polymer chain chain yenza i-LDPE iguquguquke kwaye incinci kakhulu xa ithelekiswa ne-HDPE.
I-HDPE: I-HDPE iveliswa kusetyenziswa i-Ziegler-Natta polymerization, inika ulungelelwaniso lwemolekyuli olunemigca nolwakhiwe kakhulu. Ukungabikho kwe-branching kumaketanga e-HDPE kunika ukuxinana okuphezulu kunye nokuqina okukhulu.
Iipropati Zomzimba
Iimpawu ezibonakalayo ze-LDPE kunye ne-HDPE zisiphumo esithe ngqo sezakhi zabo ze-molecular. Makhe sihlolisise kwezi zakhiwo ukuze siqonde ngcono ukuba i-LDPE kunye ne-HDPE zahluke njani ngokuxinana, amandla, ukuguquguquka, ukungafihli, kunye nokumelana nobushushu.
| Ipropati | I-LDPE | HDPE |
|---|---|---|
| Ulwakhiwo lweemolekyuli | Inesebe | Umgca |
| Ubuninzi (g/cm³) | 0.91 – 0.94 | 0.94 – 0.97 |
| Ukuba bhetyebhetye | Ubhetyebhetye kakhulu | I-flexible encinci, iqinile |
| Ukumelana nemichiza | Ukumelana kakuhle neekhemikhali ezininzi | Ukumelana neekhemikhali ezikhethekileyo |
| Ukumelana naManzi | Ukumelana nokufuma | Ukumelana kakhulu nokufuma |
| Ukumelana ne-UV | Ubuthathaka kwimitha ye-UV | I-UV-resistant ngakumbi |
| Ukomelela kunye noKuhlala ixesha elide | Amandla asezantsi kunye nokuqina | Amandla okuqina agqwesileyo kunye nokuqina |
| Ukurisayikilisha | Iyarisayikilishwa kodwa ayiqhelekanga ukurisayikilishwa | Iyarisayikilishwa kakhulu |
Ukuguquguquka kwe-LDPE kunye nendalo ekhaphukhaphu iyenza ilungele ukupakishwa, ngelixa amandla e-HDPE kunye nokuqina kuyenza ilungele ukusetyenziswa kolwakhiwo kunye noshishino.
Iipropati zeMichiza
| Ipropati | I-LDPE | HDPE |
|---|---|---|
| Ukumelana nemichiza | Ukumelana kakuhle neekhemikhali ezininzi, iiasidi, iziseko, kunye nezinyibilikisi eziphilayo | Ukuxhathisa okukhethekileyo kweekhemikhali, ukumelana noluhlu olubanzi lweekhemikhali ezibandakanya i-acids ezonakalisayo, iialkali, kunye neehydrocarbons. |
| Ukumelana naManzi | Ukumelana nokufuma | Ukumelana kakhulu nokufuma |
| Ukumelana ne-UV | Ubuthathaka kwimitha ye-UV | I-UV-resistant ngakumbi |
| Uluhlu lobushushu | Uzinzo oluphakathi lobushushu kunye nendawo yokunyibilika ngokuqhelekileyo ukusuka kwi-105 ukuya kwi-115 ° C (221 ukuya kwi-239 ° F) | Uzinzo oluphezulu lobushushu kunye nendawo yokunyibilika ngokuqhelekileyo phakathi kwe-120 kunye ne-130 ° C (248 ukuya kwi-266 ° F) |
Ukuchasana kwe-LDPE kwiikhemikhali ezahlukeneyo kuyenza ifaneleke ukupakishwa kunye nokusetyenziswa kwebhubhoratri, ngelixa i-HDPE ixhatshazwa yikhemikhali ekhethekileyo yokumelana neekhemikhali iyenza ibe lukhetho oluphezulu kwizicelo ezibandakanya iikhemikhali ezinzima kunye nokuvezwa kwangaphandle.
Inkqubo yokuVelisa
Inkqubo eyenziwa ngayo i-LDPE kunye ne-HDPE idlala indima ebalulekileyo ekumiseleni iipropati zabo kwaye, emva koko, ukufaneleka kwazo kwizicelo ezahlukeneyo.
Ukwenziwa kwe-LDPE
- I-Ethylene Polymerization: I-LDPE iveliswa yi-radical polymerization, apho iimolekyuli ze-ethylene zenziwe ipolymerized phantsi koxinzelelo oluphantsi kunye neemeko zobushushu. Oku kubangela ulwakhiwo lwepolymer enamasebe kakhulu kunye noxinzelelo oluphantsi.
- Abaqalisi kunye neeCatalysts: Abaqalisi kunye ne-catalysts basetyenziselwa ukuqalisa ukubunjwa kwamakhonkco e-polymer ukusuka kwi-ethylene monomers.
- iChain Branching: I-polymerization ye-LDPE ikhokelela kwi-branching ye-polymer chain, idala isakhiwo esifana newebhu esinikezela ukuguquguquka.
- Ukupholisa kunye nokuqinisa: Emva kokwenziwa kwepolymerization, i-LDPE ipholile kwaye iqiniswe kwifom efunwayo, njengeepellets okanye amaphepha, ukwenzela ukuqhubeka nokusebenza.
Ukwenziwa kweHDPE
- I-Ethylene Polymerization: I-HDPE iqala nge-polymerization ye-ethylene monomers phantsi koxinzelelo oluphezulu kunye neemeko zokushisa.
- IiCatalysts: Ii-catalysts ezikhethekileyo ziqeshwe ukulawula i-polymerization reaction kunye nokudala umgca, amakhonkco aphezulu.
- Akukho sebe: Ukuveliswa kwe-HDPE kubangela umgca, ulungelelwaniso oluphezulu lwemolekyuli kunye nokungabikho kwe-branching.
- Ukupholisa nokuLungiswa: Emva kokwenziwa kwepolymerization, i-HDPE ipholile kwaye icutshungulwe kwiifom ezahlukeneyo, kubandakanywa iipellets, imibhobho kunye namaphepha.
Kubalulekile ukuqaphela ukuba iinkqubo zokwenziwa kwe-LDPE kunye ne-HDPE zahluke kakhulu, ezikhokelela kulwakhiwo olwahlukileyo lwemolekyuli kwaye, ngenxa yoko, ukuhluka kweempawu zomzimba kunye neekhemikhali. Isakhiwo se-LDPE se-branched sibangela ukuguquguquka, ngelixa i-HDPE i-linear structure inika amandla kunye nokuqina.
Izicelo eziqhelekileyo
I-LDPE kunye ne-HDPE inokwabelana ngesiseko sepolymer efanayo, kodwa iipropathi zazo ezizodwa zizenza zilungele usetyenziso olwahlukileyo kumashishini ahlukeneyo.
Usetyenziso lwe-LDPE
- Iingxowa zePlastiki: Ukuba bhetyebhetye kwe-LDPE kunye nokuxhathisa ukufuma kuyenza ibe lukhetho oludumileyo lokwenza iingxowa zeplastiki ezilahlwayo ezisetyenziselwa ukuthenga igrosari, ukupakisha kunye nokugcina.
- Cofa iibhotile: Ukubumba lula kwe-LDPE kunye nokucudiswa kuyenza ilungele ukupakishwa kweemveliso ezifana neshampu, iziqholo, kunye nolunye ulwelo.
- Ukupakishwa kokutya: I-LDPE isetyenziswa ngokuqhelekileyo kwizinto zokupakisha ukutya, kubandakanywa ifilimu yokutya, izikhwama zesandwich, kunye neengxowa zefriji, ngenxa yendalo yayo engasebenziyo kunye nokuxhathisa ukufuma.
- Iifilimu zezoLimo: Ukuxhathisa kwayo kwe-UV kunye nokuqina kwenza i-LDPE ilungele usetyenziso lwezolimo, olufana nezigqubuthelo zegreenhouse kunye neefilim zemulch.
- Izixhobo zonyango kunye neLabhoratri: Ukunganyangeki kweekhemikhali ze-LDPE kunye nokulula ukwenza inzala kuyenza ilungele izinto ezifana nezikhongozeli zaselabhoratri, iiglavu ezilahlwayo, kunye netyhubhu yezonyango.
Izicelo zeHDPE
- Imibhobho yamanzi negesi: Amandla e-HDPE kunye nokuqina kwenza kube yinto ekhethekileyo yokukhetha imibhobho yokuhambisa amanzi kunye negesi, njengoko inokumelana neenkqubo zoxinzelelo oluphezulu kunye nokuxhathisa ukubola.
- IiJagi zobisi kunye neebhotile zokucoca: Ukomelela kwe-HDPE kunye nokuchasana neekhemikhali kuyenza ilungele ukupakisha ubisi, isepha, kunye nezinye iimveliso zasekhaya.
- Iingxowa zenkunkuma: Ukuqina kwe-HDPE kunye nokumelana nokugqobhoza kwenza ukuba kube yinto efanelekileyo yokwenza iingxowa zenkunkuma ezinobunzima kunye neelinen.
- Imigqomo yoShishino: Imigqomo yeHDPE kunye nezikhongozeli ziqhele ukusetyenziselwa ukugcina nokuthutha imichiza, izithambiso, kunye nezinto eziyingozi.
- Isixhobo sebala lokudlala: Ukuxhathisa kwayo kwe-UV kunye nokuqina kwenza i-HDPE ibe yinto ekhethwayo yezixhobo zebala lokudlala langaphandle, iqinisekisa ukhuseleko kunye nokuphila ixesha elide.
- IiGeombranes: I-HDPE geomembranes isetyenziselwa ulwakhiwo kunye nezicelo zokusingqongileyo zokuthintela amanzi kunye nokugcinwa kolwelo.
Ezi zicelo zibonisa ukuguquguquka kwe-LDPE kunye ne-HDPE ekuhlangabezaneni noluhlu olubanzi lweemfuno kubomi bethu bemihla ngemihla kunye namashishini ahlukeneyo. Nokuba kukulungeleka kwe-LDPE ekupakishweni okanye amandla e-HDPE kwiziseko ezingundoqo, ezi plastiki zidlala indima ebalulekileyo kuluntu lwanamhlanje.
Izinto eziluncedo nezingeloncedo
Ngelixa i-LDPE kunye ne-HDPE nganye inikezela ngeseti yeempawu ezizodwa ezenza ukuba zilungele izicelo ezahlukeneyo, kubalulekile ukuqwalasela iingenelo kunye nokungalunganga kwazo ukwenza ukhetho olunolwazi ekukhetheni izinto ezifanelekileyo.
Izinto eziluncedo ze-LDPE
- Ukuba bhetyebhetye: I-LDPE ibhetyebhetye kakhulu kwaye ihambelana ngokulula, iyenza ilungele usetyenziso olufuna ukolula kunye nokomelela.
- Ubulula bokuLungiselela: I-LDPE kulula ukusetyenzwa ngayo ngeendlela ezinje nge-extrusion kunye nokubunjwa kokuvuthela, okwenza ukuba kungabizi kakhulu ukwenza iimveliso ezahlukeneyo.
- Ukumelana neMichiza: I-LDPE ibonisa ukuxhathisa okulungileyo kwiikhemikhali ezininzi, iyenza ilungele ukupakishwa kolwelo kunye nomgubo kunye nokusetyenziswa kwizixhobo zaselabhoratri.
- Ukuxhathisa ukufuma: I-LDPE ixhathisa ukufuma kwaye ingasetyenziselwa izicelo apho ukufuma okanye ukufuma kuyinkxalabo.
- Khaphukhaphu: I-LDPE ilula ngokwentelekiso, iyenza ibe lukhetho olusebenzayo kwiimveliso apho ubunzima buyaqwalaselwa.
Izinto ezingeloncedo kwi-LDPE
- Amandla asezantsi: I-LDPE inamandla asezantsi okuqina kunye nokuqina xa kuthelekiswa ne-HDPE, inciphisa ukufaneleka kwayo kwizicelo ezithile zolwakhiwo.
- Uvakalelo lweUV: I-LDPE inovelwano kwimitha ye-UV kwaye inokwehla xa ibekwe kukukhanya kwelanga ixesha elide, okukuthintela ukusetyenziswa kwayo ngaphandle.
Izinto ezilungileyo zeHDPE
- Ukomelela kunye noKuhlala ixesha elide: I-HDPE yomelele kakhulu kwaye yomelele, inamandla agqwesileyo okuqina, iyenza ilungele usetyenziso kunye nolwakhiwo olunzima.
- Ukumelana neMichiza: Ukumelana neekhemikhali eziphezulu ze-HDPE kuyenza ilungele izicelo ezibandakanya ukuvezwa kwimichiza eyonakalisayo kunye nezinyibilikisi.
- Ukumelana naManzi: I-HDPE ixhathisa kakhulu ukufuma kunye namanzi, okwenza kube yinto ethembekileyo yokukhetha izicelo ezinxulumene namanzi.
- Ukumelana neUV: I-HDPE ixhathisa i-UV kune-LDPE, iyivumela ukuba imelane nokuvezwa ngaphandle ngaphandle kokuthotywa okubalulekileyo.
- Ukurisayikilisha: I-HDPE iphinda isetyenziswe ngokubanzi kwaye inokuguqulwa ibe yimveliso emitsha eyahlukeneyo, ekhuthaza ukuzinza kokusingqongileyo.
Ukungalungi kwe-HDPE
- Ukuqina: I-HDPE ayinakuguquguquka ngaphantsi kwe-LDPE, enokunciphisa ukusetyenziswa kwayo kwizicelo apho ukuguquguquka kubalulekile.
- Ukucutshungulwa kobunzima: I-HDPE inokufuna iindlela zokucwangcisa ezikhethekileyo ngenxa yendawo ephezulu yokunyibilika kunye nokuba ngqongqo.
- Ubunzima obunzima: I-HDPE ixinene kwaye inzima kune-LDPE, enokuthi ibe nefuthe kwiindleko zokuhamba nezokuphatha.
Ukukhetha phakathi kwe-LDPE kunye ne-HDPE kuxhomekeke kwiimfuno ezithile zesicelo sakho. Ukuba bhetyebhetye kwe-LDPE kunye nokucutshungulwa ngokulula kuyinzuzo ukupakishwa, ngelixa amandla e-HDPE kunye nokuqina kuyenza ilungele ukusetyenziswa kolwakhiwo kunye noshishino.
Impembelelo yokusingqongileyo
Njengoko uqwalaselo lwehlabathi kulondolozo lokusingqongileyo lukhula, ukuvavanya impembelelo yokusingqongileyo yemathiriyeli efana ne-LDPE kunye ne-HDPE iba yinto ebalulekileyo.
Impembelelo yokusiNgqongileyo ye-LDPE
- Ukurisayikilisha: I-LDPE inokuphinda isetyenziswe, kodwa isenokungafane isetyenziswe kwakhona xa kuthelekiswa nezinye iiplastiki. Inkqubo yokurisayikilisha ibandakanya ukunyibilika kunye nokuphinda ukhuphe imathiriyeli ukwenza iimveliso ezintsha.
- Inkunkuma kunye neNkunkuma: Iimveliso ze-LDPE ezifana neengxowa zeplastiki zinokuba negalelo kunkunkuma nakungcoliseko lokusingqongileyo xa zingalahlwanga ngokufanelekileyo okanye zisetyenziswe ngokutsha.
- Ukusetyenziswa kwamandla: Ukuveliswa kwe-LDPE kufuna amandla, kwaye ukukhutshwa kwezinto eziluhlaza, i-ethylene, inamandla amakhulu. Nangona kunjalo, ubushushu bokusebenza obuphantsi be-LDPE bunokunciphisa iinkxalabo ezinxulumene namandla.
- Ukonakala kwezinto eziphilayo: I-LDPE ayiboli lula, nto leyo ethetha ukuba iyakwazi ukuqhubeka nokusingqongileyo ixesha elide ukuba ayilawulwa kakuhle.
Impembelelo yokusingqongileyo ye-HDPE
- Ukurisayikilisha: I-HDPE inokuphinda isetyenziswe kwakhona kwaye yenye yeeplastiki eziqhele ukurisayikilishwa. Ingasetyenziselwa ukwenza uluhlu olubanzi lweemveliso, kubandakanywa izitya ezintsha kunye nemibhobho.
- Impembelelo yokuNcitshiswa kokusiNgqongileyo: Inkqubo yokuphinda isetyenziswe kwi-HDPE idla amandla amancinci xa kuthelekiswa nokuveliswa kwe-HDPE enyulu, okwenza kube yinto ekhethiweyo yokusingqongileyo.
- Ukuqina: Ukuqina kwe-HDPE kunye nokuchasana nokuthotywa kuqinisekisa ukuba iimveliso ezenziwe kuyo zinobomi obude, zinciphisa isidingo sokutshintshwa rhoqo kunye nenkunkuma.
- Ukonakala kwezinto eziphilayo: Ngokufanayo ne-LDPE, i-HDPE ayiboli phantsi kweemeko eziqhelekileyo zokusingqongileyo.
Zombini i-LDPE kunye ne-HDPE zinokuphinda zisetyenziswe, kodwa i-HDPE inerekhodi eyomeleleyo yokuphinda isetyenziswe ngenxa yemfuno yayo ephezulu kunye nokulula enokusetyenzwa ngayo kwiimveliso ezintsha. Ukongeza, ukuqina kwe-HDPE kunye nokuchasana kwimitha ye-UV kunokuba negalelo kubomi obude bemveliso, ukunciphisa impembelelo yokusingqongileyo iyonke.
Ukuqukumbela
Kummandla weeplastiki, i-LDPE kunye ne-HDPE zime njengamalungu amabini ahlukeneyo kodwa aguquguqukayo osapho lwe-polyethylene. Ukuqonda iiyantlukwano zabo kunye nezicelo kubalulekile kubasebenzi beshishini kunye nabathengi ngokufanayo.
I-LDPE, ngokuguquguquka kwayo, ifumana ukusetyenziswa kwiingxowa zeplastiki, iibhotile, kunye nokupakishwa kokutya. Nangona kunjalo, ukuchaphazeleka kwayo kukuthotywa kwe-UV kunciphisa ukusetyenziswa kwayo ngaphandle.
HDPE, eyaziwa ngokuba namandla kunye nokuqina kwayo, lukhetho lwemibhobho yamanzi kunye negesi, izitya zoshishino, kunye nokunye. Ukurisayiklishwa kwayo kunye nobude bobomi bemveliso eyandisiweyo inegalelo kwiinzuzo zokusingqongileyo.
Kwixesha eliphawulwe ziinkxalabo zokusingqongileyo, zombini i-LDPE kunye ne-HDPE zibonelela ngeendlela zokuphinda zisetyenziswe, kunye ne-HDPE eneziseko ezingundoqo zokurisayikilisha. Ukurisayikilisha, ukunciphisa ukusetyenziswa kweeplastiki ezisetyenziswa kanye, kunye nokulahlwa okunoxanduva ngamanyathelo abhekiselele kwikamva elizinzileyo.
Iimbekiselo
- ICandelo lePlastiki leBhunga laseMelika leKhemistri. (2021). Iindidi zePlastiki. Ifunyenwe kwi https://plastics.americanchemistry.com/Types-of-Plastics/
- UBrydson, J. A. (1999). Izinto zePlastiki (7th ed.). eGcuwa-Heinemann.
- UCallister, W. D. (2006). Inzululwazi yeZizinto kunye nobuNjineli: Intshayelelo (i-7th ed.). UJohn Wiley & Oonyana.
- ASTM International. (2021). I-ASTM D4976 – Inkcazo esemgangathweni ye-20 yePlastiki yePolyethylene yokuBunjwa kunye neMathiriyeli yokukhupha. Ifunyenwe kwi https://www.astm.org/Standards/D4976.htm
- ASTM International. (2021). I-ASTM D3350 – Inkcazo esemgangathweni ye-20 yePlastiki yePlastiki yePolyethylene kunye neZixhobo zokuFakela. Ifunyenwe kwi https://www.astm.org/Standards/D3350.htm
- Iinguqu zePlastiki zaseYurophu. (2021). Polyethylene (PE). Ifunyenwe kwi https://euromap.org/polyethylene-pe/
