1. Mawu Oyamba
EVA ndiye chidule cha ethylene vinyl acetate copolymer, polyolefin polima. Chifukwa cha kutentha otsika kusungunuka, fluidity wabwino, polarity ndi zinthu sanali halogen, ndipo akhoza n'zogwirizana ndi zosiyanasiyana ma polima ndi mchere ufa, angapo mawotchi ndi thupi katundu, katundu magetsi ndi processing bwino ntchito bwino, ndipo mtengo si. mkulu, msika wogulitsira ndi wokwanira, kotero zonse ngati zida zotchinjiriza chingwe, zitha kugwiritsidwanso ntchito ngati zodzaza, zotchingira; imatha kupangidwa kukhala zinthu za thermoplastic, ndipo imatha kupangidwa kukhala zinthu zolumikizirana ndi thermosetting.
EVA yogwiritsidwa ntchito mosiyanasiyana, yokhala ndi zoletsa moto, imatha kupangidwa kukhala chotchinga chopanda utsi chopanda utsi kapena halogen; sankhani VA yapamwamba kwambiri ya EVA ngati zinthu zoyambira zimathanso kupangidwa kukhala zinthu zosagwira mafuta; sankhani ndondomeko yosungunuka ya EVA yochepetsetsa, onjezani 2 mpaka 3 kudzazidwa kwa EVA flame retardants kungapangidwe kuti ntchito ya extrusion ipangidwe komanso mtengo wa zinthu zotchinga mpweya wabwino (kudzaza).
Mu pepala ili, kuchokera ku mapangidwe a EVA, kuyambitsidwa kwa ntchito yake mu makampani opanga chingwe ndi chitukuko.
2. Zomangamanga
Popanga kaphatikizidwe, kusintha chiŵerengero cha digiri ya polymerization n / m kungapangitse VA okhutira kuchokera ku 5 mpaka 90% ya EVA; kukulitsa digirii yonse ya polymerization kumatha kutulutsa kulemera kwa mamolekyulu kuchokera makumi masauzande mpaka mazana masauzande a EVA; VA zili pansi pa 40%, chifukwa cha kukhalapo kwa crystallization, kuchepa kwapang'onopang'ono, komwe kumadziwika kuti pulasitiki ya EVA; pamene VA zili zazikulu kuposa 40%, elastomer yonga mphira yopanda crystallization, imadziwika kuti EVM rabara.
1. 2 Katundu
Unyolo wa ma molekyulu a EVA ndi mawonekedwe odzaza ndi mizere, motero amakhala ndi ukalamba wabwino wa kutentha, nyengo komanso kukana kwa ozoni.
Unyolo waukulu wa molekyulu wa EVA ulibe zomangira ziwiri, mphete ya benzene, acyl, magulu amine ndi magulu ena osavuta kusuta akayaka, maunyolo am'mbali nawonso sakhala osavuta kusuta akayaka methyl, phenyl, cyano ndi magulu ena. Kuphatikiza apo, molekyulu yokhayo ilibe zinthu za halogen, chifukwa chake ndiyoyenera kwambiri kuti ikhale yotsika utsi wopanda utsi wamafuta a halogen.
Kukula kwakukulu kwa gulu la vinyl acetate (VA) mu unyolo wam'mbali wa EVA ndi polarity yake yapakatikati kumatanthauza kuti zonse zimalepheretsa chizolowezi cha vinyl nsana kuti chikhale chonyezimira komanso maanja bwino ndi mineral fillers, zomwe zimapangitsa kuti pakhale mafuta oletsa ntchito kwambiri. Izi ndi zoona makamaka pa utsi wochepa komanso kukana kopanda halojeni, monga zoletsa moto zomwe zili ndi voliyumu yoposa 50% [monga Al(OH) 3, Mg(OH) 2, ndi zina zotero] ziyenera kuwonjezeredwa kuti zigwirizane ndi zofunikira za miyezo ya chingwe. kwa kuchedwa kwa moto. EVA yokhala ndi sing'anga kupita ku VA yayikulu imagwiritsidwa ntchito ngati maziko opangira utsi wochepa komanso mafuta oletsa malawi opanda halogen okhala ndi zinthu zabwino kwambiri.
Monga gulu la EVA side chain vinyl acetate group (VA) ndi polar, VA ikakwera, polima imakhala yochulukirapo komanso kukana mafuta. Kukana kwamafuta komwe kumafunikira pamakampani opanga zingwe kumatanthawuza kutha kupirira mafuta osakhala a polar kapena ofooka a polar. Malinga ndi mfundo yofananira yofananira, EVA yokhala ndi VA yayikulu imagwiritsidwa ntchito ngati zinthu zoyambira kupanga utsi wochepa komanso chotchinga chamafuta opanda halogen komanso kukana mafuta.
Ma molekyulu a EVA mu alpha-olefin H atomu amagwira ntchito kwambiri, mu peroxide radicals kapena high-energy electron-radiation effect ndi yosavuta kutenga H cross-linking reaction, kukhala pulasitiki yolumikizidwa kapena mphira, ikhoza kupangidwa movutirapo zofunikira pakuchita. wa waya wapadera ndi zipangizo chingwe.
Kuwonjezera kwa gulu la vinyl acetate kumapangitsa kutentha kwa kutentha kwa EVA kutsika kwambiri, ndipo chiwerengero cha VA unyolo wam'mbali wamfupi ungapangitse kutuluka kwa EVA kuwonjezeka. Chifukwa chake, magwiridwe antchito ake ndiabwinoko kuposa momwe ma cell amapangidwa ndi polyethylene yofananira, kukhala maziko opangira zida zotchingira zotchingira zotchinga ndi halogen ndi zotchinga zopanda mafuta za halogen.
2 Ubwino wazinthu
2. 1 Kuchita zotsika mtengo kwambiri
Mawonekedwe a EVA akuthupi ndi makina, kukana kutentha, kukana nyengo, kukana kwa ozoni, mphamvu zamagetsi ndizabwino kwambiri. Sankhani kalasi yoyenera, ikhoza kupangidwa kukana kutentha, ntchito yoletsa moto, komanso mafuta, zosungunulira zosagwira chingwe chapadera.
Thermoplastic EVA zakuthupi zimagwiritsidwa ntchito kwambiri ndi VA zomwe zili 15% mpaka 46%, ndi index yosungunuka ya 0. 5 mpaka 4. EVA ili ndi opanga ambiri, mitundu yambiri, zosankha zingapo, mitengo yotsika, yokwanira, ogwiritsa ntchito amangofunika kutsegula gawo la EVA patsamba, mtundu, magwiridwe antchito, mtengo, malo operekera pang'onopang'ono, mutha kusankha, kwambiri. yabwino.
EVA ndi polima ya polyolefin, kuchokera ku kufewa ndi kugwiritsa ntchito kufananitsa magwiridwe antchito, ndi zinthu za polyethylene (PE) ndi chingwe chofewa cha polyvinyl chloride (PVC) ndizofanana. Koma pakufufuza kwina, mupeza EVA ndi mitundu iwiri yomwe ili pamwambapa poyerekeza ndi kukwezeka kosasinthika.
2. 2 kwambiri processing ntchito
EVA mu chingwe ntchito ndi kuchokera sing'anga ndi mkulu voteji chingwe zotchinga zakuthupi mkati ndi kunja chiyambi, ndipo kenako anawonjezera kuti halogen wopanda mafuta chotchinga. Mitundu iwiriyi ya zinthu kuchokera kumalo opangira zinthu amaonedwa kuti ndi "zinthu zodzaza kwambiri": zotetezera chifukwa chofuna kuwonjezera chiwerengero chachikulu cha conductive mpweya wakuda ndikupanga mamasukidwe ake akuchulukirachulukira, madzi amatsika kwambiri; Mafuta a halogen-free lawi retardant akufunika kuwonjezera kuchuluka kwa zoletsa moto za halogen, komanso kukhuthala kwa zinthu zopanda halogen kumachulukirachulukira, kuchuluka kwamadzi kumatsika kwambiri. Njira yothetsera vutoli ndikupeza polima yomwe imatha kukhala ndi milingo yayikulu yodzaza, komanso imakhala ndi kukhuthala kotsika komanso kusungunuka kwamadzi abwino. Pachifukwa ichi, EVA ndiye chisankho chomwe amakonda.
EVA Sungunulani mamasukidwe akayendedwe ndi extrusion processing kutentha ndi kukameta ubweya mlingo adzawonjezera kuchepa mofulumira, wosuta ayenera kusintha extruder kutentha ndi wononga liwiro, mukhoza kupanga ntchito kwambiri wa waya ndi mankhwala chingwe. Chiwerengero chachikulu cha ntchito zapakhomo ndi zakunja zikuwonetsa kuti, chifukwa chodzaza kwambiri utsi wochepa wa halogen wopanda zinthu, chifukwa kukhuthala kwake ndikwambiri, sungunulani index ndi yaying'ono kwambiri, chifukwa chake kugwiritsa ntchito tsinde laling'ono ( psinjika chiŵerengero cha zosakwana 1. 3) extrusion, pofuna kuonetsetsa zabwino extrusion khalidwe. Zipangizo za EVM zokhala ndi mphira zokhala ndi ma vulcanising agents zitha kutulutsidwa pazitsulo zonse zotulutsa mphira komanso zotulutsa zanthawi zonse. Njira yotsatsira vulcanisation (yolumikizana) imatha kuchitidwa ndi thermochemical (peroxide) cross-linking kapena electron accelerator irradiation cross-linking.
2. 3 Zosavuta kusintha ndikusintha
Mawaya ndi zingwe zili paliponse, kuchokera kumwamba mpaka pansi, kuchokera kumapiri mpaka kunyanja. Ogwiritsa ntchito waya ndi zingwe zofunikira amakhalanso osiyanasiyana komanso achilendo, pomwe mawonekedwe a waya ndi chingwe ndi ofanana, kusiyana kwake kwa magwiridwe antchito kumawonekera makamaka muzotchingira ndi zida zokutira.
Pakadali pano, kunyumba ndi kunja, PVC yofewa imawerengerabe zida zambiri za polima zomwe zimagwiritsidwa ntchito pamakampani opanga zingwe. Komabe, ndi chidziwitso chowonjezeka cha chitetezo cha chilengedwe ndi chitukuko chokhazikika.
Zipangizo za PVC zaletsedwa kwambiri, asayansi akuchita zonse zomwe angathe kuti apeze zipangizo zina za PVC, zomwe zimalonjeza kwambiri ndi EVA.
EVA imatha kusakanikirana ndi ma polima osiyanasiyana, komanso ndi mitundu yosiyanasiyana ya ufa wamchere ndi zida zothandizira kukonza, zinthu zosakanikirana zimatha kupangidwa kukhala pulasitiki ya thermoplastic ya zingwe zapulasitiki, komanso kukhala mphira wolumikizana ndi zingwe za mphira. Opanga mapangidwe amatha kutengera zofunikira za ogwiritsa (kapena muyezo), EVA ngati maziko, kuti magwiridwe antchito akwaniritse zofunikira.
3 EVA ntchito zosiyanasiyana
3. 1 Imagwiritsidwa ntchito ngati chotchinga chotchinga chotchinga pazingwe zamphamvu zothamanga kwambiri
Monga ife tonse tikudziwa, mfundo yaikulu ya zinthu kutchinga ndi conductive mpweya wakuda, mu pulasitiki kapena mphira m'munsi zinthu kuwonjezera chiwerengero chachikulu cha mpweya wakuda kwambiri kuwonongeka fluidity wa zinthu zotetezera ndi kusalala kwa mlingo extrusion. Pofuna kupewa kutulutsa pang'ono mu zingwe zothamanga kwambiri, zishango zamkati ndi zakunja ziyenera kukhala zoonda, zonyezimira, zowala komanso zofananira. Poyerekeza ndi ma polima ena, EVA imatha kuchita izi mosavuta. Chifukwa cha izi ndikuti njira ya EVA ya extrusion ndi yabwino kwambiri, kuyenda bwino, komanso sikungathe kusungunula chodabwitsa. Zida zotetezera zimagawidwa m'magulu awiri: atakulungidwa mu conductor kunja wotchedwa chishango chamkati - ndi zinthu zamkati zamkati; atakulungidwa ndi zotchingira kunja zomwe zimatchedwa chishango chakunja - ndi nsalu yakunja; Zinthu zamkati zamkati zimakhala ndi thermoplastic Zomwe zili mkati mwazenera nthawi zambiri zimakhala za thermoplastic ndipo nthawi zambiri zimachokera ku EVA yokhala ndi VA yokhala ndi 18% mpaka 28%; nsalu zakunja zimakhala zolumikizana kwambiri komanso zosenda ndipo nthawi zambiri zimachokera ku EVA yokhala ndi VA yokhala ndi 40% mpaka 46%.
3. 2 Thermoplastic ndi cross-linked flame retardant fuels
Thermoplastic flame retardant polyolefin imagwiritsidwa ntchito kwambiri pamakampani opanga zingwe, makamaka pazofunikira za halogen kapena zopanda halogen za zingwe zam'madzi, zingwe zamagetsi ndi mizere yomanga yapamwamba. Kutentha kwawo kwanthawi yayitali kumayambira 70 mpaka 90 ° C.
Kwa zingwe zamagetsi zapakati komanso zapamwamba za 10 kV ndi kupitilira apo, zomwe zimakhala ndi zofunikira kwambiri zamagetsi zamagetsi, zomwe zimalepheretsa lawi lamoto zimanyamulidwa makamaka ndi sheath yakunja. M'nyumba kapena mapulojekiti ena omwe amafunikira chilengedwe, zingwe zimafunika kukhala ndi utsi wochepa, wopanda halogen, utsi wochepa kapena utsi wochepa komanso katundu wochepa wa halogen, kotero ma polyolefin oletsa moto ku thermoplastic ndi njira yabwino.
Pazifukwa zina zapadera, m'mimba mwake si lalikulu, kutentha kukana 105 ~ 150 ℃ pakati pa chingwe chapadera, zambiri mtanda zogwirizana lawi retardant polyolefin zakuthupi, kulumikiza ake mtanda akhoza kusankhidwa ndi wopanga chingwe malinga ndi zinthu zawo kupanga. , zonse zachikhalidwe high-pressure nthunzi kapena kutentha kwambiri mchere osambira, komanso kupezeka ma elekitironi accelerator chipinda kutentha walitsa njira mtanda zogwirizana. Kutentha kwake kwanthawi yayitali kumagawidwa kukhala 105 ℃, 125 ℃, 150 ℃ mafayilo atatu, chopangiracho chikhoza kupangidwa molingana ndi zofunikira zosiyanasiyana za ogwiritsa ntchito kapena miyezo, chotchinga chamafuta cha halogen kapena halogen.
Ndizodziwika bwino kuti ma polyolefins si a polar kapena ofooka polar polar polima. Popeza ali ofanana ndi mafuta amchere mu polarity, ma polyolefin nthawi zambiri amawonedwa ngati osagonjetsedwa ndi mafuta molingana ndi mfundo yofananira. Komabe, mfundo zambiri zama chingwe kunyumba ndi kunja zimanenanso kuti kukana kolumikizana pakati kuyeneranso kukana mafuta, zosungunulira komanso ngakhale slurries, ma acid ndi alkalis. Izi ndizovuta kwa ofufuza azinthu, tsopano, kaya ku China kapena kunja, zida zofunikirazi zapangidwa, ndipo zida zake zoyambira ndi EVA.
3. 3 Zinthu zotchinga oxygen
Zingwe zomangika zamitundu yambiri zimakhala ndi ma voids ambiri pakati pa ma cores omwe amafunikira kudzazidwa kuti muwonetsetse mawonekedwe a chingwe chozungulira, ngati kudzaza mkati mwa sheath yakunja kumapangidwa ndi chotchinga chamafuta cha halogen. Kudzaza kumeneku kumakhala ngati chotchinga chamoto (oksijeni) pamene chingwe chimayaka ndipo motero amadziwika kuti "chotchinga cha okosijeni" pamakampani.
Zomwe zimafunikira kuti pakhale chotchinga mpweya wa okosijeni ndi: katundu wabwino wotuluka, kubwezeredwa kwamoto wopanda halogen (mlozera wa oxygen nthawi zambiri umaposa 40) komanso mtengo wotsika.
Chotchinga cha okosijenichi chakhala chikugwiritsidwa ntchito kwambiri pamakampani opanga zingwe kwazaka zopitilira khumi ndipo zapangitsa kuti zingwe ziziyenda bwino kwambiri. Chotchinga cha okosijeni chingagwiritsidwe ntchito pazingwe zonse zopanda halogen zoletsa malawi ndi zingwe zopanda halogen zoletsa malawi (monga PVC). Zochita zambiri zawonetsa kuti zingwe zomwe zili ndi chotchinga cha okosijeni zimatha kupitilira kuyesa kowotcha kamodzi kokha ndikuwotcha mitolo.
Kuchokera pamalingaliro a mapangidwe azinthu, izi zotchinga mpweya wa okosijeni kwenikweni ndi "ultra-high filler", chifukwa kukwaniritsa mtengo wotsika, m'pofunika kugwiritsa ntchito filler mkulu, kukwaniritsa mkulu mpweya index ayeneranso kuwonjezera mlingo waukulu. (2 mpaka 3 nthawi) ya Mg (OH) 2 kapena Al (OH) 3, ndi kutulutsa zabwino ndipo ayenera kusankha EVA ngati maziko.
3. 4 Zosinthidwa za PE sheathing
Polyethylene sheathing zipangizo sachedwa mavuto awiri: choyamba, iwo sachedwa kusungunuka breakage (ie sharkskin) pa extrusion; chachiwiri, iwo sachedwa chilengedwe nkhawa akulimbana. Yankho losavuta ndikuwonjezera gawo lina la EVA popanga. amagwiritsidwa ntchito ngati EVA yosinthidwa makamaka pogwiritsa ntchito zochepa za VA m'kalasi, ndondomeko yake yosungunuka pakati pa 1 mpaka 2 ndiyoyenera.
4. Chiyembekezo cha chitukuko
(1) EVA yakhala ikugwiritsidwa ntchito kwambiri pamakampani opanga zingwe, kuchuluka kwapachaka pakukula pang'onopang'ono komanso kokhazikika. Makamaka m'zaka khumi zapitazi, chifukwa cha kufunikira kwa chitetezo cha chilengedwe, EVA ofotokoza mafuta kukana wakhala chitukuko mofulumira, ndipo mbali ina m'malo PVC ofotokoza chingwe zinthu zimachitikira. Mtengo wake wabwino kwambiri komanso magwiridwe antchito abwino kwambiri a extrusion ndizovuta kusintha zida zina zilizonse.
(2) chingwe makampani kumwa chaka chilichonse EVA utomoni pafupi 100,000 matani, kusankha EVA utomoni mitundu, VA okhutira kuchokera otsika mpaka mkulu, pamodzi ndi chingwe chuma granulation ogwira ntchito kukula si lalikulu, kufalikira mu bizinesi iliyonse chaka chilichonse. kokha mu masauzande a matani a EVA utomoni mmwamba ndi pansi, ndipo motero sikudzakhala chidwi chachikulu chamakampani a EVA. Mwachitsanzo, kuchuluka kwakukulu kwa zinthu zotsalira zamoto za halogen zopanda moto, kusankha kwakukulu kwa VA / MI = 28/2 ~ 3 ya EVA resin (monga EVA 265 # ya DuPont ya US). Ndipo kalasi iyi ya EVA pakadali pano palibe opanga zoweta kuti apange ndikupereka. Osatchula za VA zomwe zili pamwamba kuposa 28, ndikusungunula zosakwana 3 za kupanga ndi kugawa kwa utomoni wa EVA.
(3) makampani akunja kutulutsa EVA chifukwa palibe mpikisano m'nyumba, ndipo mtengo wakhala mkulu, kwambiri kupondereza zoweta chingwe zomera kupanga chidwi. zoposa 50% za VA zomwe zili mumtundu wa rabara EVM, ndi kampani yachilendo yomwe ili ndi mphamvu, ndipo mtengo wake ndi wofanana ndi VA zomwe zili mumtundu wa 2 mpaka 3. Mitengo yotereyi, imakhudzanso kuchuluka kwa mtundu wa mphira wa EVM, kotero makampani opanga zingwe amapempha opanga zoweta za EVA, kuti apititse patsogolo kuchuluka kwa ntchito zapakhomo za EVA. Kupanga kwakukulu kwamakampani kwakhala kogwiritsa ntchito kwambiri EVA resin.
(4) Kudalira funde la chitetezo cha chilengedwe m'nthawi ya kudalirana kwa mayiko, EVA imatengedwa ndi makampani opanga chingwe kukhala chinthu chabwino kwambiri chothandizira kukana mafuta. Kugwiritsiridwa ntchito kwa EVA kukukula pamlingo wa 15% pachaka ndipo maonekedwe akulonjeza kwambiri. Kuchuluka ndi kukula kwa zipangizo zoteteza ndi sing'anga ndi mkulu voteji mphamvu chingwe kupanga ndi mlingo kukula, za 8% mpaka 10% pakati; kukana kwa polyolefin kukukulirakulira, m'zaka zaposachedwa kwakhalabe pa 15% mpaka 20% pakati, ndipo muzaka zikubwerazi 5 mpaka 10, zitha kukhalabebe izi.
Nthawi yotumiza: Jul-31-2022