Kuenzanisa kweLLDPE neLDPE.

Polyethylene ine huwandu hwakaderera hwemagadzirirwo, yakasiyana nemagadzirirwo epolyethylene ine huwandu hwakaderera hwemagadzirirwo, nekuti hapana matavi marefu echeni. Kurongeka kweLLDPE kunoenderana nemaitiro akasiyana ekugadzira nekugadzirisa eLLDPE neLDPE. LLDPE inowanzo kuumbwa ne copolymerization ye ethylene uye alpha olefins yakakwira senge butene, hexene kana octene patembiricha yakaderera uye kumanikidzwa. Iyo LLDPE polymer inogadzirwa ne copolymerization process ine kupararira kwakatetepa kwemamorekuru pane general LDPE, uye panguva imwe chete ine chimiro chakareruka chinoita kuti ive nehunhu hwakasiyana hwe rheological.

hunhu hwekuyerera kwemvura inonyunguduka

Hunhu hwekunyunguduka kweLLDPE hwakagadzirirwa zvinodiwa nemaitiro matsva, kunyanya maitiro ekubvisa firimu, ayo anogona kugadzira zvigadzirwa zveLLDPE zvemhando yepamusoro. LLDPE inoshandiswa mumisika yese yechinyakare ye polyethylene. Hunhu hwakavandudzwa hwekutambanudza, kupinda, kukanganiswa uye kudzivirira kubvaruka kunoita kuti LLDPE ive yakakodzera mafirimu. Kudzivirira kwayo kwakanyanya kupwanyika kwekumanikidzwa kwezvakatipoteredza, kudzivirira kupisa kwakaderera uye kudzivirira kupwanyika kunoita kuti LLDPE ive inokwezva mapaipi, sheet extrusion uye zvese zvinoshandiswa pakuumba. Kushandiswa kwazvino kweLLDPE senge mulch yekurasira marara uye lining yemadziva emarara.

Kugadzirwa uye Hunhu

Kugadzirwa kweLLDPE kunotanga nema catalysts esimbi anochinja, kunyanya emhando yeZiegler kana Phillips. Maitiro matsva akavakirwa pa cycloolefin metal derivative catalysts ndeimwe sarudzo yekugadzira LLDPE. Maitiro chaiwo epolymerization anogona kuitwa mu solution uye gas phase reactors. Kazhinji, octene inogadziriswa ne ethylene ne butene mu solution phase reactor. Hexene ne ethylene zvinogadziriswa mu gas phase reactor. LLDPE resin inogadzirwa mu gas phase reactor iri muchimiro che particles uye inogona kutengeswa sehupfu kana kuwedzeredzwa kuita ma pellets. Chizvarwa chitsva che super LLDPE chakavakirwa pa hexene ne octene chakagadzirwa ne Mobile, Union Carbide. Makambani akadai seNovacor neDow Plastics akatanga. Zvinhu izvi zvine muganho mukuru wekusimba uye zvine mukana mutsva wekushandisa otomatiki kubvisa mabhegi. PE resin yakaderera kwazvo (density iri pasi pe 0.910g/cc.) yakaonekwawo mumakore achangopfuura. VLDPEs ine kuchinjika uye kupfava uko LLDPE isingakwanise kuwana. Hunhu hwe resin hunowanzoonekwa mu melt index uye density. Nhamba yekunyunguduka inoratidza avhareji yehuremu hwemamorekuru eresin uye inonyanya kudzorwa nekupisa kwe reaction. Avhareji yehuremu hwemamorekuru haibatanidzwi nekugoverwa kwehuremu hwemamorekuru (MWD). Kusarudzwa kweCatalyst kunokanganisa MWD. ​​Kuwanda kwemasero kunotsanangurwa nehuwandu hwecomonomer mu polyethylene chain. Kuwanda kwecomonomer kunodzora huwandu hwematavi mapfupi echeni (hurefu hwawo hunoenderana nerudzi rwecomonomer) uye nokudaro kunodzora huwandu hweresin. Kuwanda kwecomonomer, ndiko kudzikira kweresin. Muchimiro, LLDPE yakasiyana neLDPE muhuwandu nerudzi rwematavi, LDPE ine simba rakawanda ine matavi marefu, nepo linear LDPE ine matavi mapfupi chete.

kugadzirisa

Dzese LDPE neLLDPE dzine rheology yakanaka kana kuti kuyerera kwekunyunguduka. LLDPE haina kugadzikana kwakanyanya nekuda kwekupararira kwayo kwemamorekuru uye matavi mapfupi echeni. Munguva yekuchekwa (semuenzaniso extrusion), LLDPE inoramba iine viscosity yakakura uye nekudaro yakaoma kugadzirisa kupfuura LDPE ine index imwechete yekunyunguduka. Mu extrusion, kugadzikana kwakaderera kweLLDPE kunobvumira kukurumidza kuzorora kwe polymer molecular chains, uye nekudaro kuderedzwa kwekunzwa kwechimiro chemuviri kune shanduko mu blow-up ratio. Mu extension yekunyunguduka, LLDPE inosiyana pasi pemhando dzakasiyana Kazhinji ine viscosity yakaderera nekukurumidza. Kureva kuti, haizoome zvakasimba kana yakatambanudzwa seLDPE. Inowedzera ne deformation rate ye polyethylene. LDPE inoratidza kuwedzera kunoshamisa kwe viscosity, iyo inokonzerwa nekupindirana kwemamorekuru cheni. Chiitiko ichi hachionekwi muLLDPE nekuti kushaikwa kwematavi marefu echeni muLLDPE kunoita kuti polymer isapindike. Hunhu uhwu hwakakosha zvikuru pakushandiswa kwemafirimu matete. Nekuti mafirimu eLLDPE anogona kugadzira mafirimu matete nyore nyore uku achiramba akasimba uye akaomarara. Hunhu hweLLDPE hwe rheological hunogona kupfupikiswa se "rigid in shear" uye "soft in extension".