1. Nhanganyaya
EVA ipfupiso ye ethylene vinyl acetate copolymer, polyolefin polymer. Nekuda kwekupisa kwayo kwakaderera, kuyerera kwakanaka, polarity uye zvinhu zvisiri zvehalogen, uye inogona kuenderana nemhando dzakasiyana dzemapolymers neupfu hwemineral, huwandu hwehunhu hwemakanika uye hwepanyama, hunhu hwemagetsi uye chiyero chekushanda kwekugadzirisa, uye mutengo hausi wepamusoro, kuwanikwa kwemusika kwakakwana, saka zvese sezvinhu zvekudzivirira tambo, zvinogona zvakare kushandiswa sefiller, sheathing material; zvinogona kugadzirwa kuita thermoplastic material, uye zvinogona kugadzirwa kuita thermosetting cross-linking material.
Mashandisirwo akasiyana-siyana eEVA, ane zvinodzivisa moto, anogona kugadzirwa kuita halogen isina utsi hwakawanda kana halogen; sarudza huwandu hwakawanda hweVA muEVA sezvo chinhu chepakutanga chinogonawo kugadzirwa kuita zvinhu zvinodzivirira mafuta; sarudza indekisi yekunyunguduka yeEVA iri pakati nepakati, wedzera kaviri kusvika katatu kupfuura zvinozadzisa zvinodzivisa moto zveEVA kuti zvikwanise kushandiswa pakuita kwe extrusion process uye mutengo wechinhu chinodzivisa oxygen (kuzadza) chakaenzana.
Mupepa rino, kubva pahunhu hwemaumbirwo eEVA, kuiswa kwekushandiswa kwayo muindasitiri yetambo uye tarisiro yekuvandudza.
2. Hunhu hwechivako
Pakugadzira synthesis, kuchinja chiyero che polymerisation degree n/m kunogona kugadzira VA content kubva pa5 kusvika pa90% yeEVA; kuwedzera total polymerisation degree kunogona kugadzira molecular weight kubva pamakumi ezviuru kusvika kumazana ezviuru zveEVA; VA content iri pasi pe40%, nekuda kwekuvapo kwepartial crystallisation, kusasimba kwakashata, kunowanzozivikanwa seEVA plastic; kana VA content iri pamusoro pe40%, rabha-like elastomer isina crystallisation, inowanzozivikanwa seEVM raber.
1. 2 Zvivakwa
Cheni yeEVA yemamorekuru chimiro chayo chakazara, saka ine nguva yakanaka yekukwegura pakupisa, mamiriro ekunze akanaka uye inodzivirira ozone.
Cheni huru yeEVA molecule haina mabhondi maviri, benzene ring, acyl, mapoka eamine nemamwe mapoka ari nyore kusvuta kana uchipisa, macheni epadivi haanawo macheni ari nyore kusvuta kana uchipisa methyl, phenyl, cyano nemamwe mapoka. Pamusoro pezvo, molecule pachayo haina halogen elements, saka inonyanya kukodzera mafuta asingatsvi halogen.
Kukura kukuru kweboka revinyl acetate (VA) muEVA side chain uye medium polarity yayo zvinoreva kuti zvose zvinodzivisa maitiro emusana wevinyl kuti uome uye zvinobatana zvakanaka nemineral fillers, izvo zvinogadzira mamiriro ezvinhu emafuta anodzivisa kushanda zvakanaka. Izvi zvinonyanya kuitika kune utsi hushoma uye halogen-free resists, sezvo flame retardants ine huwandu hunopfuura 50% volume [semuenzaniso Al(OH) 3, Mg(OH) 2, nezvimwewo] inofanira kuwedzerwa kuti ienderane nezvinodiwa netambo dzematare ekudzivirira moto. EVA ine huwandu hwepakati kusvika hwepamusoro hweVA inoshandiswa sehwaro hwekugadzira mafuta anodzivisa moto ane hutsi hushoma uye halogen-free ane hunhu hwakanaka.
Sezvo boka reEVA side chain vinyl acetate (VA) riri polar, kana VA iri yakawanda, polymer iri polar uye kuramba mafuta kuri nani. Kuramba mafuta kunodiwa neindasitiri yetambo kunonyanya kureva kugona kutsungirira mafuta emineral asiri polar kana asina simba. Zvichienderana nepfungwa yekuenderana kwakafanana, EVA ine VA yakawanda inoshandiswa sechinhu chepasi kugadzira chinodzivirira mafuta chisina utsi uye halogen ine kuramba mafuta kwakanaka.
Mamorekuru eEVA mu alpha-olefin H atomu mashandiro ari kushanda zvakanyanya, mu peroxide radicals kana high-energy electron-radiation effect iri nyore kutora H cross-linking reaction, inova cross-linked plastiki kana rabha, inogona kuitwa inoda mashandiro anodiwa ewaya dzakakosha uye zvinhu zvetambo.
Kuwedzerwa kweboka revinyl acetate kunoita kuti tembiricha yekunyunguduka kweEVA iderere zvakanyanya, uye huwandu hweVA short side chains hunogona kuita kuti kuyerera kweEVA kuwedzere. Nokudaro, mashandiro ayo ekuburitsa ari nani kupfuura chimiro chemamorekuru chepolyethylene yakafanana, zvichiva chinhu chinodiwa pakugadzira zvinhu zvinodzivirira zvinofambisa mafuta zvisina halogen nehalogen.
2 Zvakanakira chigadzirwa
2. 1 Kushanda kwemutengo wakakwira zvikuru
Hunhu hwemuviri uye hwemakanika hweEVA, kudzivirira kupisa, kudzivirira mamiriro ekunze, kudzivirira ozone, uye hunhu hwemagetsi hwakanaka kwazvo. Sarudza giredhi rakakodzera, rinogona kuitwa kudzivirira kupisa, kushanda kunodzora moto, asiwo mafuta, waya inodzivirira solvent.
Zvinhu zveEVA zvinoshandiswa neThermoplastic zvinoshandiswa zvakanyanya neVA iri pakati pe15% kusvika 46%, ine melt index ye0.5 kusvika 4 grades. EVA ine vagadziri vakawanda, mabrandi akawanda, sarudzo dzakasiyana-siyana, mitengo iri pakati nepakati, kuwanikwa kwakakwana, vashandisi vanongoda kuvhura chikamu cheEVA chewebhusaiti, brand, mashandiro, mutengo, nzvimbo yekutumira nekukurumidza, unogona kusarudza, zviri nyore kwazvo.
EVA ipolyolefin polymer, kubva pakupfava uye kushandiswa kwekuenzanisa mashandiro, uye polyethylene (PE) netambo yepolyvinyl chloride (PVC) yakafanana. Asi tsvakiridzo yakawedzerwa, uchawana EVA nemhando mbiri dzezvinhu dziri pamusoro apa zvichienzaniswa nehukuru husingatsiviwi.
2. 2 mashandiro akanaka kwazvo ekugadzirisa
EVA mukushandiswa kwetambo inobva pazvinhu zvekudzivirira tambo zvepakati nepamusoro mukati nekunze kwekutanga, uye gare gare yakawedzerwa kusvika kune halogen-free fuel barrier. Mhando mbiri idzi dzezvinhu kubva pakuona kwekugadzirisa dzinoonekwa se "zvinhu zvakazara zvakanyanya": zvinhu zvekudzivirira nekuda kwekuda kuwedzera huwandu hwakawanda hwekabhoni nhema inofambisa mhepo uye kuita kuti viscosity yayo iwedzere, liquidity yakadzikira zvakanyanya; halogen-free flame retardant fuel inoda kuwedzera huwandu hwakawanda hwe halogen-free flame retardants, uyewo halogen-free material viscosity yakawedzera zvakanyanya, liquidity yakadzikira zvakanyanya. Mhinduro ndeyekutsvaga polymer inogona kugamuchira madosi makuru efiller, asi ine viscosity yakaderera uye fluidity yakanaka. Nechikonzero ichi, EVA ndiyo sarudzo inosarudzwa.
Viscosity yekunyungudutsa yeEVA ine tembiricha yekugadzirisa extrusion uye shear rate inowedzera kudzikira nekukurumidza, mushandisi anongoda kugadzirisa tembiricha yekunyungudutsa uye kumhanya kwescrew, unogona kuita mashandiro akanaka ezvigadzirwa zvewaya netambo. Huwandu hwakawanda hwezvishandiso zvemumba nekunze zvinoratidza kuti, kune zvinhu zvisina halogen-utsi hwakanyanya kuzadzwa, nekuti viscosity yakakura kwazvo, melt index idiki kwazvo, saka kushandiswa chete kwe low compression ratio screw (compression ratio iri pasi pe 1.3), kuitira kuve nechokwadi chekuti extrusion yakanaka. Zvinhu zveEVM zvakavakirwa parabha zvine vulcanising agents zvinogona kuburitswa pa rabha extruders uye general purpose extruders. Maitiro anotevera e vulcanisation (cross-linking) anogona kuitwa ne thermochemical (peroxide) cross-linking kana ne electron accelerator irradiation cross-linking.
2. 3 Zviri nyore kugadzirisa nekugadzirisa
Waya netambo dziri kwese kwese, kubva kudenga kusvika pasi, kubva kumakomo kusvika kugungwa. Vanoshandisa zvinodiwa netambo netambo vanosiyana-siyana uye vanoshamisa, nepo maumbirwo etambo netambo akafanana, musiyano wekushanda kwayo unonyanya kuoneka muzvinhu zvinodzivirira kupisa nekuvhara sheath.
Kusvika pari zvino, munyika nekunze kwenyika, PVC yakapfava ichiri kushandiswa muindasitiri yetambo dzema polymer. Zvisinei, nekuwedzera kweruzivo rwekuchengetedzwa kwezvakatipoteredza nebudiriro inoenderera mberi.
Zvinhu zvePVC zvave zvisingakwanisike zvakanyanya, masayendisiti ari kuita zvese zvavanogona kuti vawane zvimwe zvinhu panzvimbo pePVC, iyo inonyanya kuvimbisa iri EVA.
EVA inogona kusanganiswa nemapolymer akasiyana-siyana, asiwo neupfu hwezvicherwa zvakasiyana-siyana uye zvinhu zvinobatsira pakugadzirisa, zvigadzirwa zvakasanganiswa zvinogona kugadzirwa kuita thermoplastic plastic yetambo dzepurasitiki, asiwo kuita rabha yakabatana yetambo dzerabha. Vagadziri vekugadzira vanogona kutevedzera zvinodiwa nemushandisi (kana zvakajairwa), EVA sechinhu chekutanga, kuti mashandiro echinhu aenderane nezvinodiwa.
3 EVA application range
3. 1 Inoshandiswa semudziyo wekudzivirira tambo dzemagetsi dzine simba guru
Sezvatinoziva tese, chinhu chikuru chechinhu chinochengetedza iblack inofambisa magetsi, mupurasitiki kana rabha, kuwedzera huwandu hwakawanda hwekabhoni dema kunokanganisa zvakanyanya kuyerera kwezvinhu zvinodzivirira uye kutsetseka kwehuwandu hwekuburitsa. Kuti kudzivirira kubuda kwechikamu mutambo dzine voltage yakawanda, zvidziviriro zvemukati nekunze zvinofanira kunge zvakatetepa, zvinopenya, zvakajeka uye zvakafanana. Zvichienzaniswa nemamwe mapolymer, EVA inogona kuita izvi zviri nyore. Chikonzero cheizvi ndechekuti maitiro ekubvisa magetsi eEVA akanaka kwazvo, anoyerera zvakanaka, uye haawanzo nyungudika. Zvinhu zvinodzivirira zvakakamurwa muzvikamu zviviri: zvakaputirwa muconductor kunze kunonzi inner shield - nezvinhu zvemukati zvescreen; zvakaputirwa muinsulation kunze kunonzi inner shield - nezvinhu zvekunze zvescreen; zvinhu zvemukati zvescreen zvinonyanya kuve thermoplastic. Zvinhu zvemukati zvescreen zvinonyanya kuve thermoplastic uye zvinowanzo shandiswa paEVA ine VA content ye18% kusvika 28%; zvinhu zvekunze zvescreen zvinonyanya kubatanidzwa uye zvinokwenenzverwa uye zvinowanzo shandiswa paEVA ine VA content ye40% kusvika 46%.
3. 2 Mafuta anodzima moto anodzivirira moto anoshandiswa nethermoplastic uye akabatana
Polyolefin inodzivirira moto inoshandiswa zvakanyanya muindasitiri yetambo, kunyanya pakushandisa tambo dzemugungwa, tambo dzemagetsi uye tambo dzekuvaka dzemhando yepamusoro, halogen kana halogen. Tembiricha dzadzo dzekushanda dzinobva pa70 kusvika 90 °C.
Kune tambo dzemagetsi dzemagetsi dziri pakati nepakati nepamusoro dze10 kV zvichikwira, dzine zvinodiwa zvakanyanya pakushanda kwemagetsi, hunhu hwemoto hunodzivirira moto hunonyanya kutakurwa nechikamu chekunze. Mune zvimwe zvivakwa kana mapurojekiti anochengetedza nharaunda, tambo dzinofanirwa kunge dziine utsi hushoma, dzisina halogen, dzine chepfu shoma kana utsi hushoma uye dzine halogen shoma, saka thermoplastic flame retardant polyolefins imhinduro inoshanda.
Kune zvimwe zvinangwa zvakakosha, dhayamita yekunze haisi yakakura, kudzivirira tembiricha iri pakati petambo yakakosha ye105 ~ 150 ℃, polyolefin ine murazvo unodzivirira zvakawanda, kubatanidza kwayo kunogona kusarudzwa nemugadziri wetambo zvichienderana nemamiriro avo ekugadzira, zvese zviri zviviri zvechinyakare zvehutsi hwepamusoro-kumanikidzwa kana bhati remunyu rinopisa zvakanyanya, asi zvakare kune nzira yemwaranzi yemagetsi yekamuri yemagetsi yemagetsi. Tembiricha yayo yekushanda kwenguva refu yakakamurwa kuita mafaira matatu e105 ℃, 125 ℃, 150 ℃, fekitari yekugadzira inogona kugadzirwa zvichienderana nezvinodiwa nevashandisi kana zviyero, halogen-isina kana halogen-ine mafuta.
Zvinozivikanwa kuti mapolyolefin haasi mapolymer epolar kana kuti asina simba. Sezvo akafanana nemafuta emaminerari mu polarity, mapolyolefin anowanzoonekwa seasinganyanyi kurwisa mafuta zvichienderana nepfungwa yekuenderana kwakafanana. Zvisinei, mitemo yakawanda yetambo munyika nekune dzimwe nyika inotaurawo kuti maresistance akabatana anofanirawo kunge aine simba rakanaka rekudzivirira mafuta, zvinonyungudutsa uye kunyange mafuta anonyunguduka, acids uye alkalis. Iri idambudziko kune vaongorori vezvinhu, ikozvino, kungave muChina kana kunze kwenyika, zvinhu izvi zvinoda simba zvakagadzirwa, uye zvinhu zvayo zvekutanga iEVA.
3. 3 Zvinhu zvinodzivirira okisijeni
Tambo dzine macore akawanda dzakasungwa dzine nzvimbo dzakawanda pakati pemacore dzinofanira kuzadzwa kuti dzive nechokwadi chekuti tambo yakatenderera inotaridzika, kana kuzadza mukati mechikamu chekunze kwakagadzirwa nechinodzivirira mafuta chisina halogen. Chidzitiro ichi chinoshanda sechinodzivirira moto (oxygen) kana tambo yatsva uye nekudaro chinozivikanwa se "chinodzivirira oxygen" muindasitiri.
Zvinodiwa zvikuru pakugadzira okisijeni ndeizvi: hunhu hwakanaka hwekuburitsa okisijeni, halogen-free flame retardancy yakanaka (oxygen index inowanzo pfuura 40) uye mutengo wakaderera.
Chidziviriro ichi cheokisijeni chave chichishandiswa zvakanyanya muindasitiri yetambo kweanopfuura makore gumi uye chave chichitungamira mukuvandudzwa kukuru mukudzora moto kwetambo. Chidziviriro cheokisijeni chinogona kushandiswa kune tambo dzisina halogen dzinodzora moto uye tambo dzisina halogen dzinodzora moto (semuenzaniso PVC). Kudzidzira kwakawanda kwakaratidza kuti tambo dzine chidziviriro cheokisijeni dzinogona kupasa bvunzo imwe chete yekupisa yakamira uye yekupisa mitsetse.
Kubva pakuona kwekugadzirwa kwezvinhu, chinhu ichi chinovhara okisijeni chaizvoizvo "chinozadza zvakanyanya", nekuti kuti uwane mutengo wakaderera, zvakakosha kushandisa chizere chakakwira, kuti uwane indekisi yepamusoro yeokisijeni inofanirawo kuwedzera chikamu chakakwira (kaviri kusvika katatu) cheMg (OH) 2 kana Al (OH) 3, uye kuti ubvise zvakanaka uye unofanira kusarudza EVA sechinhu chepakutanga.
3. 4 Zvinhu zvePE zvakagadziriswa
Zvinhu zvepurasitiki zvinoputira jira zvine matambudziko maviri: chekutanga, zvinonyunguduka (kureva sharkskin) panguva yekubuda; chechipiri, zvinokanganisa zvakatipoteredza. Mhinduro iri nyore ndeyekuwedzera chikamu cheEVA muchimiro. Inoshandiswa seEVA yakagadziriswa kazhinji ichishandisa VA yakaderera yegiredhi, indekisi yayo yekunyunguduka iri pakati pe1 kusvika 2 yakakodzera.
4. Tarisiro yebudiriro
(1) EVA yave ichishandiswa zvakanyanya muindasitiri yetambo, huwandu hwegore negore huri kukura zvishoma nezvishoma uye zvakatsiga. Kunyanya mumakore gumi apfuura, nekuda kwekukosha kwekuchengetedzwa kwezvakatipoteredza, kuramba mafuta kubva kuEVA kwave kuri kukura nekukurumidza, uye kwakatsiva zvishoma mafambiro emidziyo yetambo yakavakirwa paPVC. Kushanda kwayo kwakanaka kwemutengo uye kushanda kwayo kwakanaka kwemaitiro ekubvisa zvinhu zvakaoma kutsiva chero chimwe chinhu.
(2) kushandiswa kwegore negore kweEVA resin muindasitiri yetambo inosvika matani zviuru zana, sarudzo yemhando dzeEVA resin, VA content kubva pasi kusvika kumusoro ichashandiswa, pamwe chete ne granulation yechinhu chetambo saizi yebhizinesi haisi hombe, inopararira mubhizinesi rega rega gore rega rega chete muzviuru zvematani eEVA resin kumusoro nekudzika, uye nekudaro haizove kutariswa kukuru kweindasitiri yeEVA. Semuenzaniso, huwandu hukuru hwezvinhu zvekutanga zvehalogen-free flame retardant, sarudzo huru yeVA / MI = 28 /2 ~ 3 yeEVA resin (senge US DuPont's EVA 265 #). Uye iyi specification grade yeEVA kusvika parizvino hapana vagadziri vemumba vekugadzira nekupa. Tisingatauri nezveVA content yepamusoro kupfuura 28, uye inonyungudutsa index pasi pe3 yeimwe EVA resin kugadzirwa uye kupa.
(3) makambani ekunze anogadzira EVA nekuda kwekusava nevanokwikwidza navo mudzimba, uye mutengo wave wakakwira kwenguva refu, zvichideredza zvakanyanya kufarira kwekugadzirwa kwetambo dzemudzimba. Inopfuura 50% yeVA iri muEVM yerabha, ikambani yekune dzimwe nyika inotongwa, uye mutengo wakafanana neVA iri mukambani iyi kaviri kusvika katatu. Mitengo yakakwirira yakadaro, zvakare, inokanganisa huwandu hweEVM yerabha iyi, saka indasitiri yetambo inoda kuti vagadziri veEVA vemudzimba, vavandudze mwero wekugadzirwa kweEVA mudzimba. Kugadzirwa kwakawanda kweindasitiri kwave kushandiswa zvakanyanya kweEVA resin.
(4) Zvichienderana nekuchengetedzwa kwezvakatipoteredza munguva yepasi rose, EVA inoonekwa neindasitiri yetambo seyakanakisa pakudzivirira mafuta asingakuvadzi nharaunda. Kushandiswa kweEVA kuri kukura ne15% pagore uye tarisiro yacho yakanaka kwazvo. Huwandu nekukura kwezvinhu zvekudzivirira uye kugadzirwa kwetambo dzemagetsi emagetsi epakati nepamusoro uye mwero wekukura, anenge 8% kusvika 10% pakati; polyolefin resistances dziri kukura nekukurumidza, mumakore achangopfuura dzakaramba dziri pa15% kusvika 20% pakati, uye mumakore mashanu kusvika gumi anotevera, zvinogonawo kuchengetedza mwero uyu wekukura.
Nguva yekutumira: Chikunguru-31-2022