1. Isingeniso
I-EVA isifinyezo se-ethylene vinyl acetate copolymer, i-polyolefin polymer. Ngenxa yezinga lokushisa eliphansi elincibilikayo, i-fluidity enhle, i-polarity kanye nezakhi ezingezona ze-halogen, futhi ingahambisana nezinhlobonhlobo zama-polymers nezimpushana zamaminerali, inani lezakhiwo zemishini nezomzimba, izakhiwo zikagesi kanye nokucutshungulwa kwebhalansi yokusebenza, futhi intengo ayikho. okusezingeni eliphezulu, ukunikezwa kwemakethe kwanele, ngakho-ke kokubili njengempahla yokufaka ikhebula, ingasetshenziswa futhi njenge-filler, i-sheathing material; ingenziwa ibe impahla ye-thermoplastic, futhi ingenziwa ibe yi-thermosetting cross-linking material.
I-EVA ebanzi yokusetshenziswa, enezinqamuli zomlilo, ingenziwa ibe i-halogen engenantuthu ephansi noma isithiyo se-halogen fuel; khetha okuqukethwe okuphezulu kwe-VA kwe-EVA njengento eyisisekelo nayo ingenziwa ibe yizinto ezimelana nowoyela; khetha inkomba yokuncibilika kwe-EVA emaphakathi, engeza izikhathi ezi-2 kuya kwezi-3 ukugcwaliswa kwe-EVA flame retardants kungenziwa ekusebenzeni kwenqubo ye-extrusion kanye nentengo yesivimbelo se-oxygen esilinganiselwe (ukugcwalisa).
Kuleli phepha, kusukela kuzakhiwo zesakhiwo se-EVA, ukwethulwa kokusetshenziswa kwayo embonini yekhebula kanye namathemba okuthuthukiswa.
2. Izakhiwo zesakhiwo
Lapho kukhiqizwa i-synthesis, ukushintsha isilinganiso se-polymerisation degree n / m kungakhiqiza okuqukethwe kwe-VA kusuka ku-5 kuya ku-90% ye-EVA; ukwandisa ingqikithi ye-polymerisation degree kungakhiqiza isisindo samangqamuzana ukusuka emashumini ezinkulungwane kuya kumakhulu ezinkulungwane ze-EVA; Okuqukethwe kwe-VA ngaphansi kuka-40%, ngenxa yokuba khona kwekristalu ngokwengxenye, ukunwebeka okumpofu, okuvame ukwaziwa ngokuthi ipulasitiki ye-EVA; lapho okuqukethwe kwe-VA kungaphezu kuka-40%, i-elastomer efana nerabha ngaphandle kokucwebezela, yaziwa kakhulu ngerabha ye-EVM.
1. 2 Izakhiwo
Iketango lamangqamuzana e-EVA liyisakhiwo esigcwele umugqa, ngakho-ke sinokuguga okuhle kokushisa, isimo sezulu nokumelana ne-ozone.
Iketango eliyinhloko le-molecule ye-EVA alinawo amabhondi aphindwe kabili, iringi ye-benzene, i-acyl, amaqembu e-amine namanye amaqembu abhema kalula lapho esha, amaketango asemaceleni nawo awaqukathi ukubhema kalula lapho kushisa i-methyl, i-phenyl, i-cyano namanye amaqembu. Ngaphezu kwalokho, i-molecule ngokwayo ayinazo izakhi ze-halogen, ngakho-ke ifaneleka ngokukhethekile isisekelo samafutha esiphikisayo esingenantuthu esincane se-halogen.
Ubukhulu obukhulu beqembu le-vinyl acetate (VA) ochungechungeni oluseceleni lwe-EVA kanye ne-polarity yalo emaphakathi kusho ukuthi kokubili kuvimbela ukuthambekela komgogodla we-vinyl ukucwebezela futhi imibhangqwana kahle ngama-mineral fillers, okudala izimo zezibaseli ezivimbela ukusebenza okuphezulu. Lokhu kuyiqiniso ikakhulukazi ngokumelana nentuthu ephansi kanye ne-halogen-free, njengoba izinqamuleli zomlilo ezinevolumu engaphezu kuka-50% [isb. i-Al(OH) 3, Mg(OH) 2, njll.] kufanele zengezwe ukuze zihlangabezane nezimfuneko zezindinganiso zekhebula. ngenxa yokuncipha komlilo. I-EVA enokuqukethwe kwe-VA ephakathi nendawo ukuya kwephezulu isetshenziswa njengesisekelo sokukhiqiza intuthu ephansi kanye nezibaseli ezingenalo i-halogen ezibanga ilangabi ezinezakhiwo ezinhle kakhulu.
Njengoba i-EVA side chain vinyl acetate group (VA) i-polar, ukuphakama kwe-VA okuqukethwe, i-polar iba yi-polar futhi kuba ngcono ukumelana nowoyela. Ukumelana nowoyela okudingwa imboni yekhebula ngokuvamile kubhekisela ekhonweni lokumelana nowoyela wamaminerali angewona ama-polar noma abuthakathaka. Ngokomgomo wokuhambisana okufanayo, i-EVA enokuqukethwe okuphezulu kwe-VA isetshenziswa njengento eyisisekelo ukukhiqiza intuthu ephansi kanye nesithiyo sikaphethiloli esingenayo i-halogen enokumelana okuhle nowoyela.
Ama-athomu e-EVA ekusebenzeni kwe-athomu ye-alpha-olefin H asebenza kakhulu, kuma-radicals e-peroxide noma umphumela we-electron-radiation wamandla aphezulu kulula ukuthatha ukusabela okuxhumanisa u-H, abe ipulasitiki exhumene noma irabha, angenziwa ngezidingo zokusebenza ezinzima. wezinto zocingo ezikhethekile nekhebula.
Ukwengezwa kweqembu le-vinyl acetate kwenza izinga lokushisa elincibilikayo le-EVA lehle kakhulu, futhi inani lamaketanga amafushane we-VA angenza ukugeleza kwe-EVA kukhuphuke. Ngakho-ke, ukusebenza kwayo kwe-extrusion kungcono kakhulu kunesakhiwo samangqamuzana e-polyethylene efanayo, iba yisisekelo esithandwayo sezinto zokuzivikela ezi-semi-conductive kanye nezithiyo ze-halogen ne-halogen-free fuel.
2 Izinzuzo zomkhiqizo
2. 1 Ukusebenza kwezindleko eziphakeme kakhulu
Izakhiwo ze-EVA zomzimba nezemishini, ukumelana nokushisa, ukumelana nesimo sezulu, ukumelana ne-ozone, izakhiwo zikagesi zinhle kakhulu. Khetha ibanga elifanele, lingenziwa ukumelana nokushisa, ukusebenza kwe-flame retardant, kodwa futhi uwoyela, ikhebula elikhethekile elingamelana ne-solvent.
Impahla ye-Thermoplastic EVA isetshenziswa kakhulu ngokuqukethwe kwe-VA okungu-15% kuya ku-46%, nenkomba yokuncibilika kwamabanga angu-0. 5 kuya ku-4. I-EVA inabakhiqizi abaningi, izinhlobo eziningi, izinhlobonhlobo zezinketho, amanani aphakathi nendawo, ukunikezwa okwanele, abasebenzisi badinga kuphela ukuvula isigaba se-EVA sewebhusayithi, uhlobo, ukusebenza, intengo, indawo yokulethwa shazi, ungakhetha, kakhulu. elula.
I-EVA iyi-polymer ye-polyolefin, kusukela ekuthambile nasekusetshenzisweni kweziqhathaniso zokusebenza, kanye nempahla ye-polyethylene (PE) nezinto zekhebula ezithambile ze-polyvinyl chloride (PVC) ziyefana. Kepha ucwaningo olwengeziwe, uzothola i-EVA kanye nalezi zinhlobo ezimbili zezinto ezibonakalayo uma ziqhathaniswa nokuphakama okungenakubekezelelwa.
2. 2 ukusebenza okuhle kakhulu kokucubungula
I-EVA ekufakweni kwekhebula isuka ezintweni ezivikela ikhebula lamandla kagesi aphakathi nendawo naphezulu ngaphakathi nangaphandle kwasekuqaleni, futhi kamuva inwetshelwe kusivimbeli sikaphethiloli esingenawo i-halogen. Lezi zinhlobo ezimbili zezinto ezibonakalayo ezivela endaweni yokucubungula zibhekwa "njengezinto ezigcwele kakhulu": izinto ezivikelayo ngenxa yesidingo sokwengeza inani elikhulu le-condutive carbon black futhi lenze i-viscosity yayo yanda, i-liquidity yehla kakhulu; I-halogen-free flame retardant fuel idinga ukungeza inani elikhulu lama-flame retardants angenayo i-halogen, futhi i-viscosity ye-halogen-free viscosity inyuke kakhulu, i-liquidity yehla kakhulu. Isixazululo ukuthola i-polymer engakwazi ukufaka imithamo emikhulu ye-filler, kodwa futhi ibe ne-viscosity encibilikayo ephansi kanye ne-fluidity enhle. Ngenxa yalesi sizathu, i-EVA iyisinqumo esikhethwayo.
I-EVA melt viscosity ene-extrusion processing lokushisa kanye ne-shear rate izokwandisa ukwehla okusheshayo, umsebenzisi udinga kuphela ukulungisa izinga lokushisa le-extruder nesivinini sesikulufu, ungenza ukusebenza okuhle kakhulu kwemikhiqizo yocingo nekhebula. Inani elikhulu lezinhlelo zokusebenza ezifuywayo nezakwamanye amazwe likhombisa ukuthi, ezintweni ezigcwala kakhulu ezingenantuthu ye-halogen engenantuthu, ngenxa yokuthi i-viscosity inkulu kakhulu, inkomba yokuncibilika incane kakhulu, ngakho-ke ukusetshenziswa kwesikulufu esiphansi sokuminyanisa isilinganiso ( compression ratio of less than 1. 3) i-extrusion, ukuze kuqinisekiswe ikhwalithi enhle ye-extrusion. Izinto ze-EVM ezisuselwe enjolweni ezinama-ejenti afaka i-vulcanising zingakhishwa kuzo zombili izikhiqizo zenjoloba nezinjongo ezijwayelekile. Inqubo elandelayo ye-vulcanisation (cross-linking) ingenziwa nge-thermochemical (peroxide) cross-linking noma nge-electron accelerator irradiation cross-linking.
2. 3 Kulula ukulungisa nokuzivumelanisa nezimo
Izintambo nezintambo zikhona yonke indawo, kusukela esibhakabhakeni kuya phansi, kusukela ezintabeni kuya olwandle. Abasebenzisi bezidingo zezintambo nezekhebula nazo ziyahlukahluka futhi ziyaxaka, kuyilapho ukwakheka kocingo nekhebula kufana, umehluko wokusebenza kwawo ubonakala ikakhulukazi ekwakhiweni kwe-insulation kanye nesembozo se-sheath.
Kuze kube manje, ekhaya naphesheya, i-PVC ethambile isalokhu ilandisa ngobuningi bezinto ze-polymer ezisetshenziswa embonini yamakhebula. Nokho, ngokwanda kokuqwashisa ngokuvikelwa kwemvelo kanye nentuthuko esimeme.
Izinto ze-PVC zikhawulelwe kakhulu, ososayensi benza konke okusemandleni ukuze bathole ezinye izinto ze-PVC, okuthembisa kakhulu kuzo i-EVA.
I-EVA ingaxutshwa nama-polymer ahlukahlukene, kodwa futhi nezinhlobonhlobo zezimpushana zamaminerali kanye nezinsiza zokucubungula ezihambisanayo, imikhiqizo ehlanganisiwe ingenziwa ibe ipulasitiki ye-thermoplastic yezintambo zepulasitiki, kodwa futhi ibe yirabha exhunywe iziphambano yezintambo zenjoloba. Abaklami bokwakha bangase basekelwe kuzimfuneko zomsebenzisi (noma ezijwayelekile), i-EVA njengento eyisisekelo, ukuze kwenziwe ukusebenza kokuqukethwe kuhlangabezane nezidingo.
3 Ibanga lesicelo le-EVA
3. 1 Isetshenziswa njenge-semi-conductive shielding material kumakhebula anamandla kagesi aphezulu
Njengoba sonke sazi, into eyinhloko yezinto ezivikelayo i-carbon black conductive, kupulasitiki noma i-rubber base material ukwengeza inombolo enkulu ye-carbon black izolimaza kakhulu uketshezi lwezinto ezivikelayo kanye nokushelela kwezinga le-extrusion. Ukuze uvimbele ukukhishwa okuyingxenye ezintambo zamandla kagesi aphezulu, izihlangu zangaphakathi nezingaphandle kufanele zibe mncane, zicwebezele, zikhanye futhi zifane. Uma kuqhathaniswa namanye ama-polymer, i-EVA ingakwenza lokhu kalula. Isizathu salokhu ukuthi inqubo ye-EVA ye-extrusion inhle kakhulu, igeleza kahle, futhi ayithambekele ekuncibilikiseni isenzakalo sokuphuka. Izinto ezivikelayo zihlukaniswe izigaba ezimbili: ezisongwe ku-conductor ngaphandle okuthiwa i-internal shield - ngezinto zesikrini sangaphakathi; ezisongwe ngesivikelo esingaphandle esibizwa ngokuthi ihawu langaphandle - ngezinto zesikrini sangaphandle; Ingxenye yesikrini sangaphakathi ngokuvamile i-thermoplastic Izinto zesikrini sangaphakathi ngokuvamile zi-thermoplastic futhi ngokuvamile zisekelwe ku-EVA enokuqukethwe kwe-VA kuka-18% kuya ku-28%; izinto zesikrini sangaphandle zixhunywe kakhulu futhi ziyaxebuka futhi ngokuvamile zisekelwe ku-EVA enokuqukethwe kwe-VA okungu-40% kuya ku-46%.
3. 2 Amafutha e-Thermoplastic kanye ne-cross-linked retardant flame
I-Thermoplastic flame retardant polyolefin isetshenziswa kakhulu embonini yamakhebula, ikakhulukazi izidingo ze-halogen noma i-halogen-free yezintambo zasolwandle, izintambo zikagesi kanye nemigqa yokwakha yezinga eliphezulu. Amazinga okushisa azo esikhathi eside okusebenza asukela ku-70 kuya ku-90 °C.
Kuzintambo zamandla kagesi aphakathi nendawo naphezulu angu-10 kV nangaphezulu, anezidingo zokusebenza zikagesi eziphakeme kakhulu, izakhiwo ezivimba amalangabi zithwalwa ikakhulukazi yi-sheath yangaphandle. Kwamanye amabhilidi noma amaphrojekthi adinga imvelo, izintambo kudingeka zibe nentuthu ephansi, ezingenalo i-halogen, ubuthi obuncane noma intuthu ephansi kanye nezakhiwo ze-halogen ephansi, ngakho-ke ama-pololefin a-thermoplastic flame retardant ayisixazululo esisebenzayo.
Ngezinjongo ezithile ezikhethekile, ububanzi obungaphandle abunkulu, ukumelana nezinga lokushisa ku-105 ~ 150 ℃ phakathi kwekhebula elikhethekile, impahla exhumene ne-flame retardant polyolefin eyengeziwe, ukuxhumanisa kwayo kungakhethwa ngumkhiqizi wekhebula ngokwemibandela yabo yokukhiqiza. , kokubili isitimu esivamile esinomfutho ophezulu noma ukugeza okunosawoti okushisa kakhulu, kodwa futhi okutholakalayo kwegumbi le-electron accelerator izinga lokushisa lokusebenzisa imisebe indlela exhumene. Ukushisa kwayo kokusebenza kwesikhathi eside kuhlukaniswe ngamafayili amathathu angu-105 ℃, 125 ℃, 150 ℃, isitshalo sokukhiqiza singenziwa ngokuvumelana nezidingo ezahlukene zabasebenzisi noma amazinga, i-halogen-free noma i-halogen-containing fuel barrier.
Kwaziwa kahle ukuthi ama-polyolefin awawona ama-polar noma ama-polar polar abuthakathaka. Njengoba zifana namafutha amaminerali ku-polarity, i-polyolefin ibhekwa njengengazweli kancane kuwoyela ngokuvumelana nesimiso sokuhambisana okufanayo. Kodwa-ke, izindinganiso eziningi zamakhebula ekhaya nasemazweni angaphandle ziphinde zithi ukumelana okuxhumene kakhulu kufanele futhi kube nokumelana okuhle nowoyela, izincibilikisi ngisho nama-slurries kawoyela, ama-asidi nama-alkali. Lokhu kuyinselele kubacwaningi bezinto ezibonakalayo, manje, kungakhathaliseki ukuthi baseShayina noma phesheya, lezi zinto ezidingekayo zenziwe, futhi izinto eziyisisekelo ziyi-EVA.
3. 3 Impahla yokuvimbela umoya-mpilo
Izintambo ezinama-multi-core zinezintambo eziningi phakathi kwama-cores adinga ukugcwaliswa ukuze kuqinisekiswe ukubukeka kwekhebula eliyindilinga, uma ukugcwaliswa ngaphakathi kwe-sheath yangaphandle kwenziwa nge-halogen-free fuel barrier. Lesi sendlalelo sokugcwalisa sisebenza njengesivimbeli somlilo (i-oksijeni) lapho ikhebula livutha ngakho-ke saziwa ngokuthi "isithiyo se-oxygen" embonini.
Izidingo eziyisisekelo zento evimbela umoya-mpilo yilezi: izakhiwo ezinhle zokukhipha, ukubuyiswa komlilo okungenawo i-halogen (inkomba ye-oxygen ngokuvamile engaphezu kwama-40) kanye nezindleko eziphansi.
Lesi sivimbelo se-oxygen sisetshenziswe kakhulu embonini yekhebula iminyaka engaphezu kweshumi futhi siye saholela ekuthuthukisweni okuphawulekayo ekubambeni komlilo wezintambo. Isivimbeli somoya-mpilo singasetshenziswa kuzo zombili izintambo ezingenalo i-halogen ezinganqamuki ilangabi kanye nezintambo ezingenawo i-halogen ezinganqamuki ilangabi (isb. i-PVC). Inani elikhulu lokuzijwayeza libonise ukuthi izintambo ezinomgoqo womoya-mpilo kungenzeka ziphumelele ukuhlolwa kokushiswa okukodwa okuqondile kanye nokushiswa kwenqwaba.
Ngokombono wokwakhiwa kwezinto ezibonakalayo, le nto yokuvimbela i-oxygen empeleni "i-ultra-high filler", ngoba ukuhlangabezana nezindleko eziphansi, kuyadingeka ukusebenzisa i-filler ephezulu, ukufeza inkomba ephezulu ye-oxygen kumele futhi ingeze ingxenye ephezulu. (2 kuya kwezingu-3 izikhathi) ze-Mg ( OH) 2 noma i-Al ( OH) 3, kanye nokukhipha okuhle futhi kufanele kukhethe i-EVA njengento eyisisekelo.
3. 4 Impahla yokushelela ye-PE eguquliwe
Izinto zokushelela i-polyethylene zivame ukuba nezinkinga ezimbili: okokuqala, zivame ukuncibilika ukuphuka (okungukuthi i-sharkskin) ngesikhathi sokukhishwa; okwesibili, bathambekele ekuqhekekeni kokucindezeleka kwemvelo. Isixazululo esilula ukungeza ingxenye ethile ye-EVA ekwakhiweni. esetshenziswa njenge-EVA eguquliwe ikakhulukazi kusetshenziswa okuqukethwe kwe-VA ephansi kwebanga, inkomba yayo yokuncibilika ibe phakathi kuka-1 kuya ku-2 ifanelekile.
4. Amathemba entuthuko
(1) I-EVA isetshenziswe kabanzi embonini yekhebula, inani lonyaka ekukhuleni kancane kancane nangokuzinzile. Ikakhulukazi kule minyaka eyishumi edlule, ngenxa yokubaluleka kokuvikelwa kwemvelo, ukumelana nophethiloli okusekelwe ku-EVA kube ukuthuthuka okusheshayo, futhi ngokwengxenye kuthathe indawo yethrendi yezinto zekhebula elisekelwe ku-PVC. Ukusebenza kwayo okuhle kakhulu kwezindleko nokusebenza okuhle kakhulu kwenqubo ye-extrusion kunzima ukufaka esikhundleni sanoma yiziphi ezinye izinto.
(2) imboni yekhebula ukusetshenziswa konyaka kwe-EVA resin eduze kwamathani ayi-100,000, ukukhethwa kwezinhlobo zeresin ye-EVA, okuqukethwe kwe-VA kusuka phansi kuye phezulu kuzosetshenziswa, kuhlanganiswe nosayizi webhizinisi we-cable material granulation awumkhulu, usakazwa ebhizinisini ngalinye unyaka nonyaka. kuphela ezinkulungwaneni zamathani we-EVA resin phezulu naphansi, futhi ngaleyo ndlela ngeke kube ukunakwa kwebhizinisi elikhulu lemboni ye-EVA. Isibonelo, inani elikhulu lezinto eziyisisekelo zokubuyiswa komlilo ezingenalo halogen, ukukhetha okuyinhloko kwe-VA / MI = 28 /2 ~ 3 ye-EVA resin ( njenge-US DuPont's EVA 265 # ). Futhi leli banga lokucaciswa kwe-EVA kuze kube manje abekho abakhiqizi basekhaya abazokhiqiza futhi banikeze. Ingasaphathwa yokuqukethwe kwe-VA ephakeme kuno-28, kanye nenkomba encibilikayo ngaphansi kokungu-3 kokunye ukukhiqizwa kwe-resin ye-EVA nokunikezwa.
(3) izinkampani zakwamanye amazwe ezikhiqiza i-EVA ngenxa yokuthi azikho izimbangi zasekhaya, futhi intengo kade yaba phezulu, icindezela ngokujulile umdlandla wokukhiqiza isitshalo samakhebula wasekhaya. ngaphezu kuka-50% wokuqukethwe kwe-VA kohlobo lwe-EVM yerabha, yinkampani yangaphandle ebusayo, futhi intengo ifana nokuqukethwe kwe-VA komkhiqizo izikhathi ezi-2 kuya kwezi-3. Amanani anjalo aphezulu, aphinde athinte inani lalolu hlobo lwenjoloba i-EVM, ngakho-ke imboni yekhebula ibiza abakhiqizi be-EVA basekhaya, ukuthuthukisa izinga lokukhiqizwa kwasekhaya kwe-EVA. Ukukhiqizwa okwengeziwe kwemboni kube ukusetshenziswa okuningi kwe-EVA resin.
(4) Ngokuncika ekuvikelweni kwemvelo esikhathini sokuhwebelana kwembulunga yonke, i-EVA ithathwa imboni yamakhebula njengesisekelo esingcono kakhulu sokumelana nokushisa kwemvelo. Ukusetshenziswa kwe-EVA kukhula ngesilinganiso se-15% ngonyaka futhi umbono uthembisa kakhulu. Inani nezinga lokukhula lezinto zokuvikela kanye nokukhiqizwa kwekhebula lamandla kagesi kagesi aphakathi nendawo naphezulu kanye nezinga lokukhula, cishe amaphesenti angu-8 kuya kwangu-10 phakathi; Ukumelana ne-polyolefin kukhula ngokushesha, eminyakeni yamuva nje kusalokhu ku-15% kuya ku-20% phakathi, futhi eminyakeni ezayo emihlanu kuya kweyi-10, kungase futhi kulondoloze leli zinga lokukhula.
Isikhathi sokuthumela: Jul-31-2022