1. Intangiriro
EVA ni incamake ya ethylene vinyl acetate copolymer, polymer ya polyolefin. Bitewe n'ubushyuhe bwayo buke bwo gushonga, ubushyuhe bwayo bwiza, polarity n'ibintu bitari halogen, kandi ishobora guhuzwa n'ubwoko butandukanye bwa polymers n'ifu y'amabuye y'agaciro, imiterere myinshi ya mekanike n'iy'umubiri, imiterere y'amashanyarazi n'imikorere yayo, kandi igiciro ntikiba kiri hejuru, isoko rihagije, bityo, haba nk'ibikoresho byo gukingira insinga, bishobora no gukoreshwa nk'ibikoresho byo kuzuza, gupfuka; bishobora gukorwamo ibikoresho bya thermoplastic, kandi bishobora gukorwamo ibikoresho bihuza thermosetting.
Uburyo bwinshi bwo gukoresha EVA, hamwe n'ibintu bigabanya umuriro, bishobora gukorwamo imbogamizi nke zidafite umwotsi wa halogen cyangwa halogen; hitamo ingano nini ya VA muri EVA kuko ibikoresho by'ibanze bishobora no gukorwamo ibikoresho birwanya amavuta; hitamo igipimo cyo gushonga cya EVA kiri hagati, ongeramo inshuro 2 kugeza kuri 3 z'ibintu bigabanya umuriro bya EVA bishobora gukorwa kugira ngo bigere ku mikorere y'uburyo bwo gusohora no ku giciro cy'ibikoresho bigabanya umwuka wa ogisijeni (kuzuza).
Muri iyi nyandiko, uhereye ku miterere y'imiterere ya EVA, ishyirwa mu bikorwa ryayo mu nganda z'insinga n'iterambere.
2. Imiterere y'inyubako
Mu gukora synthesis, guhindura igipimo cya polymerisation degree n / m bishobora gutanga VA kuva kuri 5 kugeza kuri 90% bya EVA; kongera polymerisation degree yose bishobora gutanga uburemere bwa molekile kuva ku bihumbi icumi kugeza ku bihumbi amagana bya EVA; VA iri munsi ya 40%, bitewe no kuba hari crystallisation igice, flexibility idakomeye, izwi cyane nka plastic ya EVA; iyo VA iri hejuru ya 40%, elastomer isa na rubber idafite crystallisation, izwi cyane nka EVM rubber.
1. Imitungo 2
Uruhererekane rwa molekile rwa EVA ni imiterere yuzuye, bityo ikaba ifite ubushyuhe bwiza, ikirere cyiza kandi irwanya ozone.
Umunyururu mukuru wa molekile ya EVA nturimo imigozi ibiri, impeta ya benzene, acyl, amatsinda ya amine n'andi matsinda yoroshye gutwika iyo utwitse, imigozi yo ku ruhande nayo ntabwo irimo methyl, phenyl, cyano n'andi matsinda yoroshye gutwika iyo utwitse. Byongeye kandi, molekile ubwayo ntabwo irimo ibintu bya halogen, bityo ikaba ikwiriye cyane cyane ku bikoresho bya lisansi bidafite umwotsi mwinshi wa halogen.
Ingano nini y'itsinda rya vinyl acetate (VA) mu muyoboro wa EVA hamwe n'uburyo bwo hagati bwo guhindagurika bivuze ko bibuza imbaraga z'urutirigongo rwa vinyl zo gushonga neza kandi bigahuza neza n'imyunyu ngugu, ibyo bikaba ari byo bituma habaho imikorere myiza y'ibicanwa bitagira imikorere myiza. Ibi ni ukuri cyane cyane ku birwanya umwotsi muke n'ibidakoresha halogen, kuko ibicanwa bigabanya umuriro bifite ingano irenga 50% [urugero: Al (OH) 3, Mg (OH) 2, nibindi] bigomba kongerwamo kugira ngo byuzuze ibisabwa n'amabwiriza agenga insinga kugira ngo umuriro udacika. EVA ifite ingano iri hagati kugeza hejuru ya VA ikoreshwa nk'ishingiro ryo gukora ibicanwa bigabanya umwotsi muke n'ibidakoresha halogen bifite imiterere myiza.
Kubera ko itsinda rya EVA side chain vinyl acetate (VA) riri mu gice cy’umurambararo, uko VA iba nyinshi, niko polymer iba nyinshi kandi ikaba nziza. Ubudahangarwa bw’amavuta busabwa n’insinga ahanini bwerekeza ku bushobozi bwo kwihanganira amavuta y’ubutare atari mu gice cy’umurambararo cyangwa mu gice cy’umurambararo gito. Dukurikije ihame ryo guhuza ibintu kimwe, EVA ifite VA nyinshi ikoreshwa nk’igikoresho cy’ibanze kugira ngo ikore imbogamizi nke z’ibikomoka kuri peteroli zidafite umwotsi n’amavuta kandi zidafite halogen kandi zirwanya peteroli neza.
Molekile za EVA muri atome ya alpha-olefin H zikora cyane, mu miterere ya peroxide radicals cyangwa electron-radiation effect yoroshye gufata H cross-linking reaction, ziba cross-linking plastic cyangwa rubber, zishobora gukorwa ibisabwa cyane mu mikorere y’insinga zidasanzwe n’ibikoresho by’insinga.
Kongeramo itsinda rya vinyl acetate bituma ubushyuhe bwa EVA bugabanuka cyane, kandi umubare w'iminyururu migufi ya VA ishobora gutuma urujya n'uruza rwa EVA rwiyongera. Kubwibyo, imikorere yayo yo gusohora ni myiza cyane kuruta imiterere ya molekile ya polyethylene isa nayo, ikaba ariyo ikoreshwa cyane mu bikoresho byo kurinda bigabanya umuvuduko w'amashanyarazi hamwe n'inzitizi za halogen na halogen zidafite lisansi.
2 Ibyiza by'ibicuruzwa
2. 1 Imikorere ihendutse cyane
Imiterere ya EVA, ubushobozi bwo kurwanya ubushyuhe, ubushobozi bwo kurwanya ikirere, ubushobozi bwo kurwanya ozone, ubushobozi bw'amashanyarazi ni bwiza cyane. Hitamo urwego rukwiye, ubushobozi bwo kurwanya ubushyuhe, ubushobozi bwo gukumira inkongi z'umuriro, ariko nanone amavuta, ibikoresho byihariye birwanya imiyoboro y'amashanyarazi.
Ibikoresho bya EVA bya Thermoplastic bikoreshwa cyane cyane bifite VA iri hagati ya 15% na 46%, bifite igipimo cyo gushonga kiri hagati ya 0.5 na 4. EVA ifite inganda nyinshi, ibirango byinshi, amahitamo menshi, ibiciro biringaniye, serivisi zihagije, abakoresha bakeneye gufungura igice cya EVA cy'urubuga, ikirango, imikorere, igiciro, aho bigezwa mu kanya gato, ushobora guhitamo, byoroshye cyane.
EVA ni polimeri ya polyolefin, uhereye ku buryo bworoshye n'ikoreshwa ry'igereranya ry'imikorere, kandi ibikoresho bya polyethylene (PE) n'ibikoresho bya polyvinyl chloride yoroshye (PVC) bisa. Ariko ubushakashatsi burambuye, uzasangamo EVA n'ubwoko bubiri bw'ibikoresho byavuzwe haruguru ugereranije n'ubuhanga budasimburwa.
2. 2 Imikorere myiza cyane yo gutunganya
EVA mu ikoreshwa ry'insinga iva mu bikoresho bikingira insinga bifite voltage iciriritse n'iy'amashanyarazi menshi imbere no hanze yayo, hanyuma ikagera ku mupaka udafite halogen. Ubwo bwoko bubiri bw'ibikoresho mu rwego rwo gutunganya bufatwa nk' "ibikoresho byuzuye cyane": ibikoresho bikingira kubera ko hakenewe kongeramo umubare munini wa karuboni itwara amazi kandi bigatuma visitike yayo yiyongera, amazi yagabanutse cyane; lisansi igabanya umuriro idafite halogen igomba kongeramo umubare munini wa halogen igabanya umuriro, ndetse na visitike y'ibikoresho bidafite halogen yiyongera cyane, amazi yagabanutse cyane. Umuti ni ugushaka polymer ishobora kwakira doze nyinshi z'umunyururu, ariko kandi ifite visitike nkeya kandi ifite amazi meza. Kubera iyo mpamvu, EVA ni yo mahitamo meza.
Ubushyuhe bwo gushonga bwa EVA hamwe n'ubushyuhe bwo gutunganya extrusion n'umuvuduko wo gukata bizongera igabanuka ryihuse, umukoresha agomba gusa guhindura ubushyuhe bwo gusohora extruder n'umuvuduko wa screw, ushobora gukora neza cyane ku bikoresho by'insinga n'insinga. Umubare munini w'ibikoresho byo mu gihugu no mu mahanga bigaragaza ko, ku bikoresho byuzuyemo umwotsi muto udafite halogen, kubera ko ubushyuhe ari bunini cyane, ikigero cyo gushonga ari gito cyane, bityo hakoreshwa gusa screw yo gukanda (ikigero cyo gukanda kiri munsi ya 1.3), kugira ngo habeho ubuziranenge bwiza bwo gusohora extrusion. Ibikoresho bya EVM bishingiye kuri rubber bifite vulcanising agents bishobora gukurwaho haba ku bikoresho byo gukanda rubber no ku bikoresho rusange. Inzira ikurikiraho yo gukanda (cross-linking) ishobora gukorwa haba hakoreshejwe thermochemical (peroxide) cross-linking cyangwa hakoreshejwe electron accelerator irangi cross-linking.
2. 3 Byoroshye guhindura no guhindura
Insinga n'insinga biri hose, kuva mu kirere kugeza ku butaka, kuva ku misozi kugeza ku nyanja. Abakoresha insinga n'insinga bisabwa nabo baratandukanye kandi badasanzwe, mu gihe imiterere y'insinga n'insinga isa, itandukaniro ry'imikorere yazo rigaragarira ahanini mu bikoresho bikingira insinga n'ibipfukamo.
Kugeza ubu, haba mu gihugu no mu mahanga, PVC yoroshye iracyari igice kinini cy'ibikoresho bya polymer bikoreshwa mu nganda z'insinga. Ariko, hamwe n'ubumenyi bwiyongereye ku kurengera ibidukikije n'iterambere rirambye.
Ibikoresho bya PVC byaragabanijwe cyane, abahanga mu bya siyansi barimo gukora ibishoboka byose kugira ngo babone ibindi bikoresho bisimbura PVC, ikizeza cyane muri byo ni EVA.
EVA ishobora kuvangwa n'ubwoko butandukanye bwa polimeri, ariko kandi hamwe n'ubwoko butandukanye bw'ifu y'amabuye y'agaciro n'ibikoresho byo kuyitunganya bihuye, ibicuruzwa bivanze bishobora gukorwamo pulasitiki ikoreshwa mu nsinga za pulasitiki, ariko kandi bigakorwamo umupira uhuza insinga za pulasitiki. Abashushanya imvange bashobora gushingira ku bisabwa n'umukoresha (cyangwa ibisanzwe), EVA nk'ibikoresho by'ibanze, kugira ngo imikorere y'ibikoresho ihuze n'ibisabwa.
Ubwoko 3 bw'ibikoresho bya EVA
3. 1 Ikoreshwa nk'igikoresho cyo kurinda insinga z'amashanyarazi zifite amashanyarazi menshi
Nkuko twese tubizi, ibikoresho by'ingenzi by'ibikoresho byo kurinda ni umukara wa karuboni uyobora, mu gikoresho cya pulasitiki cyangwa ishingiro rya rubber kugira ngo hongerwemo umukara wa karuboni mwinshi bizangiza cyane uburyo ibikoresho byo kurinda bisohokamo ndetse no koroherwa n'urwego rwo hanze. Kugira ngo hirindwe ko igice cy'amazi kiva mu nsinga zifite voltage nyinshi, ingabo z'imbere n'iz'inyuma zigomba kuba zoroshye, zirabagirana, zirabagirana kandi zihuye. Ugereranyije n'izindi polymer, EVA ishobora kubikora byoroshye kurushaho. Impamvu ni uko inzira yo gukuramo ya EVA ari nziza cyane, igenda neza, kandi ntishobora gushonga. Ibikoresho byo kurinda bigabanyijemo ibyiciro bibiri: bipfunyitse mu gikoresho cyo hanze cyitwa ingabo y'imbere - hamwe n'ibikoresho byo mu idirishya ry'imbere; bipfunyitse mu gikoresho cyo hanze cyitwa ingabo y'inyuma - hamwe n'ibikoresho byo mu idirishya ry'inyuma; ibikoresho byo mu idirishya ry'imbere ahanini ni thermoplastic Ibikoresho byo mu idirishya ry'imbere ahanini ni thermoplastic kandi akenshi bishingiye kuri EVA ifite VA iri hagati ya 18% na 28%; ibikoresho byo mu idirishya ry'inyuma ahanini bifatanye kandi bishobora gukurwaho kandi akenshi bishingiye kuri EVA ifite VA iri hagati ya 40% na 46%.
3. 2 Ibicanwa bikoresha umuriro bikoresha thermoplastic n'ibikomoka ku muriro bihuza
Polyolefini igabanya umuriro ikoreshwa cyane mu nganda z'insinga, ahanini mu bijyanye n'insinga zo mu mazi, insinga z'amashanyarazi n'imiyoboro y'ubwubatsi yo mu rwego rwo hejuru, ifite ubushyuhe buri hagati ya 70 na 90 °C.
Ku nsinga z'amashanyarazi ziciriritse n'izifite ingufu nyinshi za kV 10 no hejuru yazo, zifite ingufu nyinshi zikoreshwa mu mikorere y'amashanyarazi, imiterere y'umuriro ikoreshwa ahanini n'icyuma cyo hanze. Mu nyubako cyangwa imishinga imwe n'imwe ikenera ibidukikije, insinga zisabwa kugira umwotsi muke, zidafite halogen, uburozi buke cyangwa umwotsi muke hamwe n'imiterere y'umuriro muke, bityo polyolefins zikoresha umuriro mu buryo bwa thermoplastic ni igisubizo cyiza.
Ku mpamvu zimwe na zimwe zidasanzwe, umurambararo w'inyuma ntabwo ari munini, ubushyuhe buri hagati y'insinga yihariye, ibikoresho byinshi bya polyolefin bigabanya umuriro, guhuza kwayo bishobora gutoranywa n'uruganda rukora insinga hakurikijwe imiterere yabyo, haba mu mwuka usanzwe ushyushye cyane cyangwa mu bwogero bw'umunyu bushyushye cyane, ariko kandi haboneka imirasire y'ubushyuhe bw'icyumba ikoreshwa mu buryo buhuriweho na electron. Ubushyuhe bwayo bw'igihe kirekire bugabanyijemo dosiye eshatu, uruganda rukora rushobora gukorwa hakurikijwe ibisabwa bitandukanye n'abakoresha cyangwa ibipimo, imbogamizi zidafite halogen cyangwa halogen.
Birazwi neza ko polyolefini ari polimeri zidafite polar cyangwa polar polar nkeya. Kubera ko zisa na peteroli y'amabuye y'agaciro muri polarity, polyolefini ahanini zifatwa nk'izidakomeye ku mavuta hakurikijwe ihame ryo guhuza ibintu kimwe. Ariko, amahame menshi y'insinga mu gihugu no mu mahanga nayo avuga ko cross-linked resistances zigomba kandi kuba zirwanya amavuta, solvents ndetse no ku mavuta ya peteroli, aside na alkali. Iki ni ikibazo ku bashakashatsi mu by'ibikoresho, ubu, haba mu Bushinwa cyangwa mu mahanga, ibi bikoresho bigoye byarakozwe, kandi ibikoresho byabyo by'ibanze ni EVA.
3. 3 Ibikoresho bikingira umwuka wa ogisijeni
Insinga zifite impande nyinshi zifite icyuho kinini hagati y’insinga zigomba kuzuzwa kugira ngo insinga izengurutse igaragare neza, niba ubwinjiriro buri mu gisenge cy’inyuma bukozwe mu ruzitiro rudafite halogen. Uru ruzitiro rukora nk'uruzitiro rw'umuriro (ogisijeni) iyo insinga ihiye, bityo rukaba ruzwi nk'"uruzitiro rw'umwuka" mu nganda.
Ibisabwa by'ibanze ku bikoresho bikingira umwuka wa ogisijeni ni: imiterere myiza yo gusohora, kudakoresha umuriro wa halogen (ikigero cya ogisijeni gikunze kuba hejuru ya 40) n'igiciro gito.
Iyi nzitizi ya ogisijeni imaze imyaka irenga icumi ikoreshwa cyane mu nganda zikora insinga, kandi yatumye habaho iterambere rikomeye mu kugabanya umuriro kw'insinga. Iyi nzitizi ya ogisijeni ishobora gukoreshwa haba ku nsinga zitagira umuriro zitagira halogen ndetse no ku nsinga zitagira umuriro zitagira halogen (urugero: PVC). Imyitozo myinshi yagaragaje ko insinga zifite uruzitiro rwa ogisijeni zishobora gutsinda ibizamini byo gutwika bihagaze rimwe no gutwika mu matsinda.
Ukurikije uburyo ibintu bitegurwa, iyi miterere y’ibikoresho bikingira umwuka mu by’ukuri ni “icyuzuzo kinini cyane”, kuko kugira ngo ubone igiciro gito, ni ngombwa gukoresha icyuma cyuzuzo kinini, kugira ngo ugere ku gipimo cya ogisijeni kinini ugomba kongeramo igipimo kinini (inshuro 2 kugeza kuri 3) cya Mg (OH) 2 cyangwa Al (OH) 3, kandi kugira ngo uvanemo ibintu byiza ugomba guhitamo EVA nk’igikoresho cy’ibanze.
3. 4 Ibikoresho byahinduwe byo gupfuka icyuma cya PE
Ibikoresho byo gutwikiramo polyethylene bikunze guhura n'ibibazo bibiri: icya mbere, bishobora kwangirika (ni ukuvuga sharkskin) mu gihe cyo gusohora; icya kabiri, bishobora kwangirika ku bidukikije. Umuti woroshye ni ukongeramo igice runaka cya EVA mu buryo bwo kuyitunganya. Ikoreshwa nka EVA yahinduwe ahanini ikoresheje VA nkeya mu rugero rwayo, igipimo cyayo cyo gushonga kiri hagati ya 1 na 2 kirakwiye.
4. Ibyiza by'iterambere
(1) EVA yakoreshejwe cyane mu nganda zikora insinga, ingano yayo ikaba ari buri mwaka mu iterambere rirambye kandi rirambye. Cyane cyane mu myaka icumi ishize, bitewe n'akamaro ko kurengera ibidukikije, kurwanya ibikomoka kuri lisansi bishingiye kuri EVA byateye imbere byihuse, kandi byasimbuye igice cy'uburyo insinga zikoresha PVC zikoresha. Ibiciro byayo byiza cyane n'imikorere yayo myiza mu gutunganya insinga biragoye gusimbuza ibindi bikoresho.
(2) ikoreshwa rya resin ya EVA buri mwaka hafi toni 100.000 mu nganda z'insinga, ubwoko bwa resin ya EVA buhitamo, ingano ya VA kuva hasi kugeza hejuru izakoreshwa, hamwe n'ingano y'ibikoresho bya resin ya granulation y'ikigo ntabwo ari nini, ikwirakwizwa muri buri kigo buri mwaka gusa mu toni ibihumbi bya resin ya EVA hejuru no hasi, bityo ntabwo izaba ari yo sosiyete ikomeye mu nganda za EVA. Urugero, umubare munini w'ibikoresho by'ibanze bitagira umuriro wa halogen, amahitamo nyamukuru ya VA / MI = 28 /2 ~ 3 bya resin ya EVA (nk'iya US DuPont's EVA 265 # ). Kandi iyi grade ya EVA kugeza ubu nta nganda zikora mu gihugu zikora kandi zitanga. Tutibagiwe n'ingano ya VA iri hejuru ya 28, kandi igabanuka ry'ingano iri munsi ya 3 y'ibindi bikorwa bya resin ya EVA n'ibitangwa.
(3) amasosiyete yo mu mahanga akora EVA kubera ko nta bahanganye bo mu gihugu, kandi igiciro cyamaze igihe kinini, bigabanya cyane ubushake bwo gukora insinga zo mu gihugu. Ibirenze 50% by'ibikubiye muri VA bya EVM yo mu bwoko bwa rubber, ni sosiyete yo mu mahanga yiganjemo, kandi igiciro gisa n'ibikubiye muri VA byo mu bwoko bwa rubber inshuro 2 kugeza kuri 3. Ibiciro nk'ibi binini, nabyo bigira ingaruka ku bwinshi bw'iyi EVM yo mu bwoko bwa rubber, bityo inganda zikora insinga zisaba abakora EVA bo mu gihugu, kunoza umuvuduko w'umusaruro wa EVA mu gihugu. Umusaruro mwinshi w'inganda wakoreshejwe cyane muri resin ya EVA.
(4) Bishingikirije ku muraba wo kurengera ibidukikije mu gihe cy’ubucucike bw’isi, EVA ifatwa n’inganda zikora insinga nk’ibikoresho by’ibanze byiza byo kurwanya ibikomoka kuri peteroli bitangiza ibidukikije. Ikoreshwa rya EVA riri kwiyongera ku kigero cya 15% ku mwaka kandi icyizere ni cyiza cyane. Ingano n’umuvuduko w’ubwiyongere bw’ibikoresho byo kurinda ndetse n’umusaruro w’insinga z’amashanyarazi ziciriritse n’izifite voltage nyinshi n’umuvuduko w’ubwiyongere, hafi 8% kugeza 10% hagati; ubudahangarwa bwa polyolefin buri kwiyongera cyane, mu myaka ya vuba aha bwagumye kuri 15% kugeza 20% hagati, no mu myaka 5 kugeza 10 iri imbere, nabyo bishobora gukomeza iki gipimo cy’ubwiyongere.
Igihe cyo kohereza: 31 Nyakanga-2022