1. Intshayelelo
U-EVA sisishunqulelo se-ethylene vinyl acetate copolymer, i-polyolefin polymer. Ngenxa yobushushu obuphantsi bokunyibilika, ubumanzi obulungileyo, i-polarity kunye ne-non-halogen element, kwaye inokuhambelana neentlobo ngeentlobo zeepolymers kunye nomgubo wezimbiwa, inani leepropathi zoomatshini kunye nezomzimba, iipropati zombane kunye nokulungelelanisa ukusebenza, kwaye ixabiso alikho. phezulu, unikezelo lwemarike lwanele, ngoko zombini njengezinto zokugquma intambo, zingasetyenziswa njenge-filler, i-sheathing material; inokwenziwa ibe yimathiriyeli ye-thermoplastic, kwaye inokwenziwa kwi-thermosetting cross-linking material.
Uluhlu olubanzi lwe-EVA yokusetyenziswa, kunye ne-flame retardants, ingenziwa ibe yi-halogen ephantsi yomsi okanye isithintelo se-halogen fuel; khetha umxholo ophezulu we-VA we-EVA njengento esisiseko nayo inokwenziwa kwizinto ezichasene neoli; khetha isalathisi sokunyibilika kwe-EVA ephakathi, yongeza i-2 kumaxesha e-3 ukuzaliswa kwe-EVA i-flame retardants ingenziwa kwi-extrusion process performance kunye nexabiso le-barrier-barrier-barrier (ukuzaliswa) kwezinto.
Kulo phepha, ukusuka kwiipropati zesakhiwo se-EVA, ukuqaliswa kwesicelo sayo kwishishini lekhebula kunye nethemba lophuhliso.
2. Iimpawu zesakhiwo
Xa uvelisa i-synthesis, ukutshintsha umlinganiselo we-polymerisation degree n / m kunokuvelisa umxholo we-VA ukusuka kwi-5 ukuya kwi-90% ye-EVA; ukwandisa idigri yepolymerisation iyonke kunokuvelisa ubunzima bemolekyuli ukusuka kumashumi amawaka ukuya kumakhulu amawaka e-EVA; Umxholo we-VA ongaphantsi kwe-40%, ngenxa yobukho be-crystallization eyingxenye, i-elasticity embi, eyaziwa ngokuba yi-plastiki ye-EVA; xa umxholo we-VA ungaphezulu kwe-40%, i-elastomer efana ne-rubber ngaphandle kwe-crystallization, yaziwa ngokuqhelekileyo njenge-rubber ye-EVM.
1. 2 Iipropati
Itsheyini yemolekyuli ye-EVA sisakhiwo esigcweleyo esinemigca, ngoko ke inokuguga okuhle kobushushu, imozulu kunye nokumelana ne-ozone.
EVA molekyuli main chain ayiqulathanga double bonds, benzene ring, acyl, amaqela amine kunye namanye amaqela kulula ukutshaya xa utshisa, amatyathanga asecaleni nawo aziqulathanga lula ukutshaya xa utshisa imethyl, phenyl, cyano kunye namanye amaqela. Ukongezelela, i-molecule ngokwayo ayinayo i-halogen elements, ngoko ifanelekile ngokukodwa kwisiseko se-fuel resistive fuel base-halogen.
Ubungakanani obukhulu beqela le-vinyl acetate (VA) kwikhonkco lecala le-EVA kunye ne-polarity yalo ephakathi kuthetha ukuba zombini inqanda ukuthambekela kwe-vinyl backbone ukuba ibe yikristale kunye nezibini kakuhle kunye nezihluzi zezimbiwa, ezidala iimeko ze-fuel barrier barriers. Oku kuyinyani ngakumbi kumsi ophantsi kunye nokuchasana kwe-halogen-free, njengoko iiretardants zomlilo ezinomthamo ongaphezulu kwe-50% yesiqulatho sevolumu [umz. Al(OH) 3, Mg(OH) 2, njl.njl.] kufuneka zongezwe ukuhlangabezana neemfuno zemigangatho yentambo ngenxa yokungabikho kwedangatye. I-EVA enomxholo ophakathi ukuya kwi-VA ephezulu isetyenziswe njengesiseko sokuvelisa umsi ophantsi kunye ne-halogen-free flame retardant fuels kunye neempawu ezintle.
Njengoko i-EVA side chain vinyl acetate group (VA) i-polar, iphezulu umxholo we-VA, i-polar ngakumbi i-polar kwaye ingcono ukuchasana kweoli. Ukuxhatshazwa kweoli okufunwa yi-cable industry ikakhulu kubhekiselele kumandla okumelana ne-non-polar okanye i-oyile ye-polar mineral. Ngokomgaqo wokuhambelana okufanayo, i-EVA enomxholo ophezulu we-VA isetyenziswe njengento esisiseko ukuvelisa umsi ophantsi kunye ne-halogen-free barrier barrier kunye nokuchasana kweoli.
Iimolekyuli ze-EVA kwintsebenzo ye-athom ye-alpha-olefin H iyasebenza ngakumbi, kwi-peroxide radicals okanye i-high-energy electron-radiation effect kulula ukuyithatha i-H cross-linking reaction, ibe yiplastiki edibeneyo okanye irabha, inokwenziwa ngokunyanzelisa iimfuno zokusebenza. yocingo olukhethekileyo kunye nezixhobo zentambo.
Ukongezwa kweqela le-vinyl acetate lenza ukuba iqondo lokushisa elinyibilikayo le-EVA lehle kakhulu, kwaye inani le-VA elifutshane leetyathanga ezisecaleni lingenza ukuhamba kwe-EVA kunyuke. Ngoko ke, ukusebenza kwayo kwe-extrusion kungcono kakhulu kunesakhiwo se-molecular ye-polyethylene efanayo, ibe yinto ekhethiweyo yesiseko sezinto zokukhusela i-semi-conductive kunye nezithintelo ze-halogen kunye ne-halogen-free fuel.
2 Iinzuzo zemveliso
2. 1 Ukusebenza kweendleko eziphezulu kakhulu
Iimpawu ze-EVA zomzimba kunye noomatshini, ukumelana nobushushu, ukumelana nemozulu, ukuxhathisa kwe-ozone, iimpawu zombane zilungile kakhulu. Khetha udidi olufanelekileyo, lunokwenziwa ukuxhathisa ubushushu, ukusebenza kwe-flame retardant, kodwa kunye ne-oyile, i-solvent-resistant special cable material.
Izinto ze-EVA ze-Thermoplastic zisetyenziswa kakhulu kunye nomxholo we-VA we-15% ukuya kwi-46%, kunye ne-melt index ye-0. 5 ukuya kuma-4 amabakala. I-EVA inabenzi abaninzi, iimveliso ezininzi, uluhlu olubanzi lweenketho, amaxabiso aphakathi, unikezelo olwaneleyo, abasebenzisi bafuna kuphela ukuvula icandelo le-EVA lewebhusayithi, uphawu, ukusebenza, ixabiso, indawo yokuhambisa ngokujonga nje, ungakhetha, kakhulu. eluncedo.
I-EVA yipolymer ye-polyolefin, ukusuka kwi-softness kunye nokusetyenziswa kothelekiso lwentsebenzo, kunye ne-polyethylene (PE) kunye nezinto eziphathekayo ze-polyvinyl chloride (PVC) ziyafana. Kodwa uphando olongezelelekileyo, uya kufumana i-EVA kunye nezi ntlobo zimbini zemathiriyeli zingasentla xa kuthelekiswa nobukhulu obungenakuthathelwa indawo.
2. 2 ukusebenza kakuhle kokusebenza
I-EVA kwisicelo sentambo ivela kwisixhobo sokukhusela ikhebula eliphakathi kunye nephezulu ngaphakathi nangaphandle kwesiqalo, kwaye kamva yandiswe kwisithintelo samafutha e-halogen-free. Ezi ntlobo zimbini zezinto eziphathekayo ukusuka kwindawo yokucubungula zibhekwa "njengezinto ezizaliswe kakhulu": izinto ezikhuselayo ngenxa yesidingo sokongeza inani elikhulu le-carbon conductive emnyama kunye nokwenza i-viscosity yayo yanda, i-liquidity yehla ngokukhawuleza; I-halogen-free flame retardant fuel idinga ukongeza inani elikhulu le-halogen-free flame retardants, kwakhona i-viscosity ye-halogen-free viscosity inyuke ngokukhawuleza, umbane wehla ngokukhawuleza. Isisombululo kukufumana i-polymer enokuthi ifake iidosi ezinkulu zokuzalisa, kodwa ibuye ibe ne-viscosity ephantsi yokunyibilika kunye ne-fluidity enhle. Ngesi sizathu, i-EVA lolona khetho lukhethwayo.
I-EVA inyibilika i-viscosity kunye ne-extrusion processing yeqondo lokushisa kunye nesantya sokucheba siya kwandisa ukwehla ngokukhawuleza, umsebenzisi kufuneka ahlengahlengise ubushushu be-extruder kunye nesantya se-screw, unokwenza ukusebenza kakuhle kweemveliso zocingo kunye neentambo. Inani elikhulu lezicelo zasekhaya nezangaphandle zibonisa ukuba, umsi ophantsi ophantsi we-halogen-free, ngenxa yokuba i-viscosity inkulu kakhulu, isalathisi sokunyibilika sincinci kakhulu, ngoko ke kuphela ukusetyenziswa komlinganiselo ophantsi woxinzelelo (umlinganiselo woxinzelelo ongaphantsi kwe 1. 3) i-extrusion, ukwenzela ukuba kuqinisekiswe umgangatho omhle we-extrusion. Izixhobo ze-EVM ezisekwe kwirabha ezineejenti zokuvuza zinokukhutshelwa kuzo zombini iirubha ezikhupha irabha kunye neenjongo ngokubanzi. I-vulcanisation elandelayo (i-cross-linking) inkqubo inokuqhutyelwa mhlawumbi nge-thermochemical (peroxide) i-cross-linking okanye nge-electron accelerator irradiation cross-linking.
2. 3 Kulula ukuyilungisa kunye nokuziqhelanisa
Iingcingo kunye neentambo zikho kuyo yonke indawo, ukusuka esibhakabhakeni ukuya emhlabeni, ukusuka ezintabeni ukuya elwandle. Abasebenzisi beemfuno zocingo kunye neentambo zikwahluka kwaye ziyamangalisa, ngelixa isakhiwo socingo kunye nentambo ifana, ukungafani kwayo komsebenzi kubonakaliswa ikakhulu kwi-insulation kunye nezixhobo zokugubungela i-sheath.
Ukuza kuthi ga ngoku, ekhaya nakwamanye amazwe, iPVC ethambileyo isabala uninzi lwezixhobo zepolymer ezisetyenziswa kushishino lweentambo. Nangona kunjalo, ngokunyuka kolwazi lokukhuselwa kwendalo kunye nophuhliso oluzinzileyo.
Izinto zePVC zithintelwe kakhulu, izazinzulu zenza konke okusemandleni ukufumana enye imathiriyeli kwi-PVC, eyona nto ithembisayo yi-EVA.
I-EVA inokudityaniswa neentlobo ngeentlobo zeepolymers, kodwa kunye neentlobo ngeentlobo zomgubo wezimbiwa kunye nezixhobo zokucoca ezihambelanayo, iimveliso ezidityanisiweyo zinokwenziwa kwiplastiki ye-thermoplastic kwiintambo zeplastiki, kodwa nakwirabha edityaniswe ngokunqamlezileyo kwiintambo zerabha. Abaqulunqi bokuqulunqa banokusekelwe kwiimfuno zomsebenzisi (okanye ezisemgangathweni), i-EVA njengesiseko sezinto eziphathekayo, ukwenza ukusebenza kwezinto eziphathekayo ukuhlangabezana neemfuno.
Uluhlu lwesicelo se-3 EVA
3. 1 Isetyenziswa njengesixhobo esikhuselayo sesemi-conductive kwiintambo zombane ezinevoltage ephezulu.
Njengoko sonke siyazi, izinto eziphambili zezinto ezikhuselayo yi-carbon black conductive, kwiplastiki okanye kwisiseko se-rubber yokongeza inani elikhulu lekhabhoni emnyama iya kuhlahloka kakhulu umbane wezinto ezikhuselayo kunye nokugudiswa kwenqanaba le-extrusion. Ukuthintela ukukhutshwa okuyingxenye kwiintambo eziphezulu ze-voltage, izikhuselo zangaphakathi nangaphandle kufuneka zibe zincinci, zikhanye, zikhanye kwaye zifane. Xa kuthelekiswa nezinye iipolymers, i-EVA inokwenza oku ngokulula. Isizathu soku kukuba inkqubo ye-EVA ye-extrusion ilungile ngokukodwa, ihamba kakuhle, kwaye ayifuni ukunyibilika isiganeko sokuphuka. Izinto ezikhuselayo zihlulwe zibe ziindidi ezimbini: zihlanganiswe kwi-conductor ngaphandle ebizwa ngokuba yi-internal shield - kunye ne-inner screen material; isongelwe kwisigqubuthelo esingaphandle esibizwa ngokuba sisikhuselo sangaphandle - kunye nemathiriyeli yesikrini sangaphandle; Izinto zesikrini zangaphakathi ziyi-thermoplastic Isixhobo sesikrini sangaphakathi sininzi se-thermoplastic kwaye sihlala sisekelwe kwi-EVA kunye nomxholo we-VA we-18% ukuya kwi-28%; izinto zesikrini zangaphandle zidibene kakhulu kwaye ziya peelable kwaye zihlala zisekwe kwi-EVA enomxholo we-VA we-40% ukuya kwi-46%.
3. I-2 Thermoplastic kunye ne-cross-linked flame retardant fuels
I-Thermoplastic flame retardant polyolefin isetyenziswa kakhulu kwishishini lentambo, ngakumbi kwiimfuno ze-halogen okanye i-halogen-free yeentambo zaselwandle, iintambo zombane kunye neentambo zokwakha ezikumgangatho ophezulu. Amaqondo obushushu okusebenza kwawo exesha elide asuka kuma-70 ukuya kuma-90 °C.
Kwiintambo zamandla ombane ophakathi kunye nophezulu we-10 kV nangaphezulu, ezineemfuno zombane eziphezulu kakhulu, iipropathi zokubuyiswa komlilo zithwalwa ikakhulu sisingxobo sangaphandle. Kwezinye izakhiwo ezifuna indalo okanye iiprojekthi, iintambo kufuneka zibe nomsi ophantsi, i-halogen-free, ubuthi obuphantsi okanye umsi ophantsi kunye neempawu ze-halogen eziphantsi, ngoko ke i-pololefin ye-thermoplastic flame retardant sisisombululo esisebenzayo.
Ngeenjongo ezithile ezikhethekileyo, i-diameter yangaphandle ayinkulu, ukumelana nobushushu kwi-105 ~ 150 ℃ phakathi kwentambo ekhethekileyo, i-polyolefin edityanisiweyo ngakumbi yomlilo, ukudibanisa kwayo kunokukhethwa ngumenzi wentambo ngokweemeko zabo zokuvelisa. , zombini umphunga wesiqhelo woxinzelelo oluphezulu okanye ibhafu yetyuwa enobushushu obuphezulu, kodwa ikwakhona ne-electron ye-accelerator yegumbi lobushushu elifumanekayo ngendlela edityanisiweyo. Ukushisa kwayo kwexesha elide lokusebenza kuhlukaniswe kwiifayile ze-105 ℃, 125 ℃, 150 ℃ ezintathu, isityalo sokuvelisa singenziwa ngokweemfuno ezahlukeneyo zabasebenzisi okanye imigangatho, i-halogen-free okanye i-halogen-containing barrier barrier.
Kuyaziwa ukuba iipolyolefins azikho kwi-polar okanye zibuthathaka iipolima zepolar. Njengoko zifana ne-oyile yamaminerali kwi-polarity, i-polyolefins ithathwa njengenganyangekiyo kwioli ngokomgaqo wokuhambelana okufanayo. Nangona kunjalo, imigangatho emininzi yeentambo ekhaya nakwamanye amazwe ikwachaza ukuba ukuxhathisa okudityanisiweyo kufuneka kuxhathise i-oyile, izinyibilikisi kunye nakwi-oyile slurries, iiasidi kunye neealkali. Lo ngumngeni kubaphandi bezinto eziphathekayo, ngoku, nokuba ngaba e-China okanye kumazwe angaphandle, ezi zixhobo ezifunwayo ziye zaphuhliswa, kwaye isiseko sayo yi-EVA.
3. 3 Imathiriyeli yokuthintela ioksijini
Iintambo ezininzi ezinqamlekileyo zine-voids ezininzi phakathi kwee-cores ezifuna ukugcwaliswa ukuze kuqinisekiswe ukubonakala kwekhebula elijikelezileyo, ukuba ukuzaliswa ngaphakathi kwe-sheath yangaphandle ye-halogen-free barrier barrier. Olu luhlu lokuzalisa lusebenza njengesithintelo somlilo (i-oksijeni) xa ikhebula livutha kwaye ngoko liyaziwa ngokuba "ngumqobo we-oxygen" kwishishini.
Iimfuno ezisisiseko zezinto ezithintela i-oksijeni zezi: iipropati ezilungileyo ze-extrusion, i-halogen-free flame retardancy (isalathisi se-oksijeni ngokuqhelekileyo ngaphezu kwe-40) kunye neendleko eziphantsi.
Esi sithintelo se-oksijini sisetyenziswe ngokubanzi kwishishini lekhebula iminyaka engaphezu kweshumi kwaye liye lakhokelela ekuphuculeni okubonakalayo kwi-flame retardancy yeentambo. Isithintelo se-oksijini sinokusetyenziselwa zombini iintambo ezingenayo i-halogen ezibuyiswa ngamadangatye kunye neentambo ezingenazo i-halogen ezibuthisa amadangatye (umz. i-PVC). Isixa esikhulu sokuziqhelanisa sibonise ukuba iintambo ezinesithintelo se-oksijini kunokwenzeka ukuba ziphumelele ukutshisa okuthe nkqo kunye novavanyo lokutshisa inqwaba.
Ukususela kumbono wokuqulunqwa kwezinto eziphathekayo, le nto yokuthintela i-oksijini ngokwenene "i-ultra-high filler", kuba ukuhlangabezana neendleko eziphantsi, kuyimfuneko ukusebenzisa i-filler ephezulu, ukufezekisa isalathisi esiphezulu se-oxygen kufuneka kwakhona ukongeza umlinganiselo ophezulu. (2 ukuya ku-3 amaxesha) kaMg (OH) 2 okanye Al (OH) 3, kunye nokugqithisa okulungileyo kwaye kufuneka ukhethe i-EVA njengento esisiseko.
3. 4 Isixhobo sokucheba sePE esilungisiweyo
Izinto ze-polyethylene sheathing zixhomekeke kwiingxaki ezimbini: okokuqala, zivame ukunyibilika ukuphuka (oko kukuthi i-sharkskin) ngexesha lokukhupha; okwesibini, baqhelene nokuqhekeka koxinzelelo lokusingqongileyo. Isisombululo esilula kukongeza umlinganiselo othile we-EVA ekuqulunqweni. isetyenziswe njenge-EVA eguquliweyo ikakhulu isebenzisa umxholo ophantsi we-VA webakala, isalathisi sayo sokunyibilika phakathi kwe-1 ukuya kwe-2 ifanelekile.
4. Amathuba ophuhliso
(1) I-EVA isetyenziswe ngokubanzi kwishishini lekhebula, isixa sonyaka ekukhuleni ngokuthe ngcembe nangokuzinzileyo. Ngokukodwa kule minyaka ilishumi idlulileyo, ngenxa yokubaluleka kokhuseleko lokusingqongileyo, i-EVA-based resistance fuel iye yaba luphuhliso olukhawulezayo, kwaye ngokuyinxenye ithathe indawo yePVC-based cable material trend. Ukusebenza kweendleko ezigqwesileyo kunye nokusebenza okugqwesileyo kwenkqubo ye-extrusion kunzima ukubuyisela nayiphi na enye imathiriyeli.
(2) ishishini lekhebula ukusetyenziswa konyaka kwe-resin ye-EVA kufutshane neetoni ze-100,000, ukhetho lweentlobo ze-resin ze-EVA, umxholo we-VA ukusuka ezantsi ukuya phezulu uya kusetyenziswa, udityaniswe ne-cable material granulation ubungakanani beshishini abukho bukhulu, busasazeka kwishishini ngalinye ngonyaka. kuphela kumawaka eetoni ze-EVA resin phezulu naphantsi, kwaye ke ayisayi kuba yingqalelo yeshishini elikhulu le-EVA. Ngokomzekelo, inani elikhulu le-halogen-free flame retardant material base, ukhetho oluphambili lwe-VA / MI = 28 / 2 ~ 3 ye-resin ye-EVA (njenge-US DuPont's EVA 265 #). Kwaye eli bakala lichaziweyo le-EVA ukuza kuthi ga ngoku akukho bavelisi basekhaya ukuvelisa kunye nokubonelela. Ungakhankanyi umxholo we-VA ophezulu kune-28, kunye nesalathisi esincibilikayo esingaphantsi kwe-3 yezinye imveliso ye-resin ye-EVA kunye nokubonelela.
3 ngaphezu kwe-50% yomxholo we-VA we-rubber-type EVM, yinkampani yangaphandle elawulwayo, kwaye ixabiso lifana nomxholo we-VA we-brand 2 ukuya ku-3 amaxesha. Amaxabiso aphakamileyo anjalo, kwakhona, achaphazela inani le-rubber yohlobo lwe-EVM, ngoko imboni yekhebula ibiza abavelisi be-EVA basekhaya, ukuphucula izinga lemveliso yasekhaya ye-EVA. Imveliso eyongezelelekileyo yeshishini ibe kukusetyenziswa kakhulu kwe-EVA resin.
(4) Ngokuthembela kumaza okukhusela okusingqongileyo kwixesha lokudityaniswa kwehlabathi, i-EVA ithathwa njengeshishini lekhebula njengeyona nto isisiseko sokumelana nokusingqongileyo. Ukusetyenziswa kwe-EVA kukhula ngesantya se-15% ngonyaka kwaye umbono uthembisa kakhulu. Isixa kunye nesantya sokukhula kwezixhobo zokukhusela kunye noveliso lwentambo yombane ophakathi kunye nophezulu kunye nesantya sokukhula, malunga ne-8% ukuya kwi-10% phakathi; I-pololefin resistances ikhula ngokukhawuleza, kwiminyaka yakutshanje ihleli kwi-15% ukuya kwi-20% phakathi, kwaye kwi-5 ezayo ezayo kwiminyaka eyi-10, inokugcina eli zinga lokukhula.
Ixesha lokuposa: Jul-31-2022