Linear yakaderera density polyethylene, structural yakasiyana kubva general low density polyethylene, nokuti hapana refu cheni mapazi.Iwo mutsara weLLDPE unoenderana neakasiyana kugadzirwa uye kugadzirisa maitiro eLLDPE neLDPE.LLDPE inowanzo umbwa necopolymerization ye ethylene uye yakakwirira alpha olefins yakadai sebutene, hexene kana octene pazasi tembiricha uye kumanikidza.Iyo LLDPE polymer inogadzirwa neiyo copolymerization process ine yakamanikana mamorekuru huremu kugovera pane general LDPE, uye panguva imwechete ine mutsara chimiro chinoita kuti ive neyakasiyana rheological properties.
melt flow properties
Iyo yakanyunguduka kuyerera maitiro eLLDPE anochinjirwa kune izvo zvinodikanwa zveiyo nyowani maitiro, kunyanya iyo firimu extrusion process, inogona kuburitsa yakakwira mhando LLDPE zvigadzirwa.LLDPE inoshandiswa mumisika yese yechinyakare ye polyethylene.Yakakwidziridzwa kutambanudza, kupinda, kukanganisa uye kubvarura kuramba zvivakwa kunoita LLDPE yakakodzera mafirimu.Kupokana kwayo kunopesana nemamiriro ekunze kusagadzikana kupaza, yakaderera tembiricha kukanganisa kuramba uye warpage kuramba inoita kuti LLDPE inakidze pombi, sheet extrusion uye ese ekuumba maapplication.Ikozvino kushandiswa kweLLDPE kwakangoita semuvharo wemarara uye maramba emadziva emarara.
Kugadzira uye Hunhu
Kugadzirwa kweLLDPE kunotanga neshanduko yesimbi inokonzeresa, kunyanya yeZiegler kana Phillips mhando.Maitiro matsva akavakirwa pa cycloolefin simbi inotorwa catalysts ndeimwe sarudzo yeLLDPE kugadzirwa.Iyo chaiyo polymerization reaction inogona kuitwa mune mhinduro uye gasi chikamu reactors.Kazhinji, octene iri copolymerized ne ethylene uye butene mune mhinduro chikamu reactor.Hexene uye ethylene inopolymerized mune gasi chikamu reactor.Iyo LLDPE resin inogadzirwa mugasi chikamu reactor iri mune yakasarudzika fomu uye inogona kutengeswa sehupfu kana kuenderera mberi kugadziridzwa kuita pellets.Chizvarwa chitsva che super LLDPE chakavakirwa pahexene uye octene chakagadzirwa neMobile, Union Carbide.Makambani akadai seNovacor neDow Plastics akatanga.Zvishandiso izvi zvine muganho wakakura wekuomarara uye zvine mukana mutsva wekubvisa mabhegi otomatiki.Very low density PE resin (density pazasi 0.910g/cc.) yakaonekwawo mumakore achangopfuura.VLDPES ine kuchinjika uye kupfava izvo LLDPE isingakwanise kuwana.Izvo zvimiro zve resins zvinowanzo ratidzwa mu melt index uye density.Iyo melt index inoratidza avhareji yemamolekyulu kurema kweresin uye inonyanya kudzorwa nekuita tembiricha.Avhareji yehuremu hwema molecular yakazvimirira pane molecular weight distribution (MWD).Kusarudzwa kweCatalyst kunokanganisa MWD.Density inotarirwa nekusangana kwecomonomer muketani yepolyethylene.Iyo comonomer concentration inodzora nhamba yematavi echeni mapfupi (kureba kwayo kunoenderana nerudzi rwecomonomer) uye nekudaro inodzora resin density.Iyo yakakwirira iyo comonomer concentration, inodzikira iyo resin density.Zvimiro, LLDPE yakasiyana neLDPE muhuwandu uye rudzi rwematavi, high-pressure LDPE ine matavi akareba, nepo mutsara LDPE ine mapazi mapfupi chete.
processing
Ose ari maviri LDPE neLLDPE ane yakanakisa rheology kana kunyungudika kuyerera.LLDPE ine kushomeka kwekugera nekuda kwekutetepa kwayo kwema molecular huremu kugovera uye mapfupi cheni matavi.Panguva yekuveura (eg extrusion), LLDPE inochengeta viscosity yakakura uye saka yakanyanya kuoma kugadzirisa kupfuura LDPE ine yakafanana melt index.Muextrusion, iyo yakaderera shear senitivity yeLLDPE inobvumira kukurumidza kushushikana kuzorora kwepolymer molecular cheni, uye nekudaro kuderedzwa kwekunzwa kwezvimiro zvemuviri kuchinja mukuputira-up ratio.Mukunyunguduka kwekuwedzera, LLDPE inosiyana pasi pemhando dzakasiyana-siyana Kazhinji ine yakaderera viscosity pakumhanya.Ndiko kuti, haizoomese kana yakatambanudzwa seLDPE.Wedzera ne deformation rate ye polyethylene.LDPE inoratidza kuwedzera kunoshamisa kwe viscosity, iyo inokonzerwa nekupinzwa kwemaketani emamorekuru.Chiitiko ichi hachionekwe muLLDPE nekuti kushomeka kwemapazi echeni refu muLLDPE kunochengetedza polima isina kupinzwa.Ichi chivakwa chakakosha zvakanyanya kune yakaonda firimu application.Nekuti mafirimu eLLDPE anogona nyore kugadzira mafirimu matete achichengetedza simba rakakwirira uye kuoma.Iyo rheological properties yeLLDPE inogona kupfupikiswa se "yakaoma mukuveura" uye "yakapfava mukuwedzera".
Nguva yekutumira: Oct-21-2022