Ukuqhathaniswa kwe-LLDPE ne-LDPE.

I-polyethylene eqondile enesisindo esiphansi, ehlukile ngokwesakhiwo kune-polyethylene ejwayelekile enesisindo esiphansi, ngoba azikho amagatsha eketanga elide. Ukulingana kwe-LLDPE kuncike ezinqubweni ezahlukene zokukhiqiza nokucubungula ze-LLDPE ne-LDPE. I-LLDPE ivame ukwakheka yi-copolymerization ye-ethylene nama-olefin aphezulu e-alpha njenge-butene, i-hexene noma i-octene ekushiseni okuphansi kanye nengcindezi. I-polymer ye-LLDPE ekhiqizwa yinqubo ye-copolymerization inokusabalalisa kwesisindo sama-molecule okuncane kune-LDPE ejwayelekile, futhi ngesikhathi esifanayo inesakhiwo esiqondile esenza ibe nezakhiwo ezihlukile ze-rheological.

izakhiwo zokugeleza kokuncibilika

Izici zokugeleza kokuncibilika kwe-LLDPE zivumelaniswa nezidingo zenqubo entsha, ikakhulukazi inqubo yokukhipha amafilimu, engakhiqiza imikhiqizo ye-LLDPE esezingeni eliphezulu. I-LLDPE isetshenziswa kuzo zonke izimakethe zendabuko ze-polyethylene. Ukwelula okuthuthukisiwe, ukungena, ukuthinteka kanye nezakhiwo zokumelana nokudabuka kwenza i-LLDPE ifaneleke kumafilimu. Ukumelana kwayo okuhle kakhulu nokuqhekeka kokucindezeleka kwemvelo, ukumelana nokushisa okuphansi kanye nokumelana nokugoba kwenza i-LLDPE ikhange kumapayipi, ukukhishwa kwamaphepha kanye nazo zonke izinhlelo zokusebenza zokubumba. Ukusetshenziswa kwakamuva kwe-LLDPE kufana ne-mulch yezindawo zokulahla udoti kanye ne-linings yamachibi kadoti.

Ukukhiqizwa kanye nezici

Ukukhiqizwa kwe-LLDPE kuqala ngama-catalyst ensimbi yokuguquguquka, ikakhulukazi ohlobo lwe-Ziegler noma lwe-Phillips. Izinqubo ezintsha ezisekelwe kuma-catalyst ensimbi asuselwa ku-cycloolefin zingenye indlela yokukhiqizwa kwe-LLDPE. Ukusabela kwangempela kwe-polymerization kungenziwa kuma-reactors esisombululo kanye nesigaba segesi. Ngokuvamile, i-octene i-copolymerized nge-ethylene ne-butene ku-reactor yesigaba sesisombululo. I-Hexene ne-ethylene zi-polymerized ku-reactor yesigaba segesi. I-resin ye-LLDPE ekhiqizwa ku-reactor yesigaba segesi isesimweni sezinhlayiya futhi ingathengiswa njengempuphu noma icutshungulwe ibe ama-pellets. Isizukulwane esisha se-super LLDPE esekelwe ku-hexene ne-octene sakhiwe yi-Mobile, i-Union Carbide. Izinkampani ezifana ne-Novacor ne-Dow Plastics zethulwe. Lezi zinto zinomkhawulo omkhulu wokuqina futhi zinamandla amasha okusetshenziswa okuzenzakalelayo kokususa izikhwama. I-resin ye-PE ephansi kakhulu (ubuningi obungaphansi kuka-0.910g/cc.) nayo ivele eminyakeni yamuva. I-VLDPEs inokuguquguquka nobumnene i-LLDPE engenakukufeza. Izakhiwo zama-resin ngokuvamile zibonakala ku-melt index kanye nobuningi. Inkomba yokuncibilika ibonisa isisindo sama-molecule esimaphakathi se-resin futhi ngokuyinhloko ilawulwa izinga lokushisa lokusabela. Isisindo sama-molecule esimaphakathi asincikile ekusabalalisweni kwesisindo sama-molecule (MWD). Ukukhethwa kwe-Catalyst kuthinta i-MWD. Ubuningi bunqunywa ukugcwala kwe-comonomer ku-polyethylene chain. Ukugcwala kwe-comonomer kulawula inani lamagatsha amafushane eketanga (ubude bawo buxhomeke ohlotsheni lwe-comonomer) futhi ngaleyo ndlela kulawula ukugcwala kwe-resin. Uma ukugcwala kwe-comonomer kuphakeme, kulapho ukugcwala kwe-resin kuba phansi. Ngokwesakhiwo, i-LLDPE ihlukile ku-LDPE ngenani nohlobo lwamagatsha, i-LDPE enengcindezi ephezulu inamagatsha amade, kuyilapho i-LDPE eqondile inamagatsha amafushane kuphela.

ukucubungula

Kokubili i-LDPE ne-LLDPE zinokugeleza okuhle kakhulu kwe-rheology noma ukuncibilika. I-LLDPE inozwela oluncane lokucheba ngenxa yokusatshalaliswa kwayo okunciphile kwesisindo sama-molecule kanye namagatsha amafushane e-chain. Ngesikhathi sokucheba (isb. i-extrusion), i-LLDPE igcina i-viscosity enkulu ngakho-ke kunzima kakhulu ukuyicubungula kune-LDPE ene-melt index efanayo. Ekukhipheni, ukuzwela okuphansi kokucheba kwe-LLDPE kuvumela ukukhululeka okusheshayo kokucindezeleka kwamaketanga e-polymer molecular, ngaleyo ndlela ukuzwela okuncishisiwe kwezakhiwo zomzimba ezishintshayo kusilinganiso sokuqhuma. Ekunwetshweni kokuncibilika, i-LLDPE iyahlukahluka ngaphansi kwezinhlobo ezahlukahlukene Ngokuvamile ine-viscosity ephansi ngesivinini. Okusho ukuthi, ngeke iqine uma inwetshiwe njenge-LDPE. Yanda ngesilinganiso sokuguqulwa kwe-polyethylene. I-LDPE ikhombisa ukwanda okumangazayo kwe-viscosity, okubangelwa ukuvaleka kwamaketanga e-molecule. Lesi simo asibonwa ku-LLDPE ngoba ukuntuleka kwamagatsha e-chain amade ku-LLDPE kugcina i-polymer ingenakho ukuvaleka. Lesi sici sibaluleke kakhulu ekusetshenzisweni kwefilimu encane. Ngoba amafilimu e-LLDPE angenza kalula amafilimu amancane ngenkathi egcina amandla aphezulu nokuqina. Izakhiwo ze-rheological ze-LLDPE zingafingqwa ngokuthi “ziqinile uma zishefa” kanye “zithambile uma zinwetshiwe”.