1. Taw qhia
EVA yog lub npe luv rau ethylene vinyl acetate copolymer, polyolefin polymer. Vim nws tsis tshua muaj melting kub, zoo fluidity, polarity thiab non-halogen ntsiab, thiab tuaj yeem sib xws nrog ntau yam polymers thiab ntxhia hmoov, ntau yam khoom siv thiab lub cev, cov khoom siv hluav taws xob thiab kev ua haujlwm sib npaug, thiab tus nqi tsis yog. siab, kev lag luam khoom txaus txaus, yog li ob qho tib si raws li cov khoom siv hluav taws xob cable, kuj tuaj yeem siv los ua cov khoom siv, cov khoom siv sheathing; tuaj yeem ua rau cov khoom siv thermoplastic, thiab tuaj yeem ua rau hauv cov khoom siv thermosetting cross-linking khoom.
EVA ntau yam kev siv, nrog cov nplaim hluav taws, tuaj yeem ua rau cov pa taws tsis muaj halogen lossis halogen roj teeb meem; xaiv cov ntsiab lus siab VA ntawm EVA raws li cov khoom siv hauv paus kuj tuaj yeem ua rau cov khoom siv roj-resistant; xaiv lub melt index ntawm nruab nrab EVA, ntxiv 2 mus rau 3 lub sij hawm lub filling ntawm EVA nplaim retardants yuav ua tau rau extrusion txheej txheem kev ua tau zoo thiab tus nqi ntawm ib tug ntau balanced oxygen barrier ( filling ) khoom.
Nyob rau hauv daim ntawv no, los ntawm cov yam ntxwv ntawm EVA, kev taw qhia ntawm nws daim ntawv thov nyob rau hauv lub cable kev lag luam thiab kev loj hlob prospects.
2. Cov yam ntxwv zoo
Thaum tsim cov synthesis, hloov qhov piv ntawm polymerisation degree n / m tuaj yeem tsim cov ntsiab lus VA ntawm 5 mus rau 90% ntawm EVA; nce tag nrho cov degree polymerization tuaj yeem tsim qhov hnyav molecular los ntawm kaum tawm txhiab mus rau pua pua txhiab EVA; VA cov ntsiab lus qis dua 40%, vim muaj cov crystallisation ib nrab, elasticity tsis zoo, feem ntau hu ua EVA yas; Thaum cov ntsiab lus VA ntau dua 40%, cov roj hmab zoo li elastomer tsis muaj crystallisation, feem ntau hu ua EVM roj hmab.
1. 2 Khoom
Cov saw hlau molecular ntawm EVA yog cov qauv sib xyaw ua ke, yog li nws muaj qhov zoo thaum tshav kub kub, huab cua thiab ozone tsis kam.
EVA molecule lub ntsiab saw tsis muaj ob daim ntawv cog lus, benzene nplhaib, acyl, amine pawg thiab lwm pab pawg yooj yim rau haus luam yeeb thaum hlawv, sab chains kuj tsis muaj cov pa luam yeeb yooj yim thaum hlawv methyl, phenyl, cyano thiab lwm pawg. Tsis tas li ntawd, lub molecule nws tus kheej tsis muaj cov ntsiab lus halogen, yog li nws yog qhov tshwj xeeb tshaj yog tsim rau cov pa taws uas tsis muaj halogen-free resistive roj puag.
Qhov loj loj ntawm vinyl acetate (VA) pab pawg nyob rau hauv EVA sab saw thiab nws nruab nrab polarity txhais tau hais tias nws ob leeg inhibits lub siab nyiam ntawm vinyl nraub qaum mus crystallize thiab khub niam txiv zoo nrog cov pob zeb hauv av fillers, uas tsim cov kev mob rau kev ua haujlwm siab barrier fuels. Qhov no yog qhov tseeb tshwj xeeb rau cov pa luam yeeb tsawg thiab tsis muaj halogen resists, raws li cov nplaim hluav taws uas muaj ntau dua 50% cov ntsiab lus ntim [piv txwv li Al (OH) 3, Mg (OH) 2, thiab lwm yam] yuav tsum tau ntxiv kom tau raws li cov kev cai ntawm cov qauv cable. rau nplaim retardancy. EVA nrog rau nruab nrab mus rau siab VA cov ntsiab lus yog siv los ua lub hauv paus tsim cov pa luam yeeb tsawg thiab cov nplaim hluav taws tsis muaj halogen uas muaj cov khoom zoo heev.
Raws li EVA sab saw yas acetate pawg (VA) yog polar, qhov siab dua VA cov ntsiab lus, cov polar ntau dua cov polymer thiab cov roj kuj zoo dua. Cov roj kuj xav tau los ntawm kev lag luam cable feem ntau yog hais txog kev muaj peev xwm tiv taus cov roj tsis muaj polar lossis cov roj ntxhia tsis muaj zog. Raws li lub hauv paus ntsiab lus ntawm kev sib raug zoo zoo sib xws, EVA nrog cov ntsiab lus VA siab yog siv los ua cov khoom siv los tsim cov pa luam yeeb tsawg thiab halogen tsis muaj roj teeb meem nrog cov roj zoo.
EVA molecules nyob rau hauv alpha-olefin H atom kev ua tau zoo dua, nyob rau hauv cov peroxide radicals los yog high-zog electron radiation nyhuv yog ib qho yooj yim mus nqa H cross-linking cov tshuaj tiv thaiv, ua cross-linked yas los yog roj hmab, yuav ua tau kom xav tau kev ua tau zoo. ntawm cov khoom siv tshwj xeeb hlau thiab cable.
Qhov sib ntxiv ntawm cov vinyl acetate pawg ua rau qhov kub ntawm EVA poob qis, thiab tus naj npawb ntawm VA luv sab chains tuaj yeem ua rau cov dej ntws ntawm EVA nce. Yog li ntawd, nws cov extrusion kev ua tau zoo dua ntau dua li cov qauv molecular ntawm cov polyethylene zoo sib xws, dhau los ua cov khoom siv zoo tshaj plaws rau cov khoom siv tiv thaiv semi-conductive thiab halogen thiab halogen tsis muaj roj teeb meem.
2 Cov khoom zoo
2. 1 Kev ua haujlwm siab heev
EVA lub cev thiab txhua yam khoom, kub tsis kam, huab cua tsis kam, ozone tsis kam, hluav taws xob zoo heev. Xaiv cov qib uas tsim nyog, tuaj yeem ua rau kub tsis kam, nplaim taws ua haujlwm, tab sis kuj tseem muaj roj, hnyav-resistant tshwj xeeb cable khoom.
Cov khoom siv thermoplastic EVA feem ntau yog siv nrog VA cov ntsiab lus ntawm 15% mus rau 46%, nrog rau qhov ntsuas kub ntawm 0. 5 mus rau 4 qib. EVA muaj ntau lub tuam txhab, ntau hom, ntau yam kev xaiv, tus nqi nruab nrab, cov khoom siv txaus, cov neeg siv tsuas yog yuav tsum qhib EVA ntu ntawm lub vev xaib, hom, kev ua tau zoo, nqe, xa khoom qhov chaw ntawm ib nrais muag, koj tuaj yeem xaiv, heev. yooj yim.
EVA yog ib qho polyolefin polymer, los ntawm qhov muag muag thiab kev siv kev sib piv, thiab cov khoom siv polyethylene (PE) thiab mos polyvinyl chloride (PVC) cable cov ntaub ntawv zoo sib xws. Tab sis kev tshawb fawb ntxiv, koj yuav pom EVA thiab ob hom khoom siv saum toj no piv nrog qhov zoo tshaj qhov hloov tsis tau.
2. 2 kev ua haujlwm zoo heev
EVA nyob rau hauv daim ntawv thov cable yog los ntawm nruab nrab thiab high voltage cable shielding khoom nyob rau hauv thiab sab nraum thaum pib, thiab tom qab ntawd txuas mus rau halogen-dawb roj barrier. Ob hom khoom siv los ntawm kev ua tiav yog suav tias yog "cov khoom siv ntau heev": cov khoom siv tiv thaiv vim tias yuav tsum tau ntxiv cov pa roj carbon ntau ntau thiab ua rau nws cov viscosity nce, lub liquidity poob sharply; halogen-dawb nplaim retardant roj yuav tsum tau ntxiv ib tug loj tus naj npawb ntawm halogen-dawb nplaim retardants, kuj halogen-dawb cov ntaub ntawv viscosity nce sharply, lub liquidity poob sharply. Txoj kev daws teeb meem yog nrhiav tau ib lub polymer uas tuaj yeem ua kom haum cov tshuaj loj ntawm cov muab tub lim, tab sis kuj muaj cov viscosity tsawg thiab cov dej zoo. Vim li no, EVA yog qhov kev xaiv zoo tshaj plaws.
EVA yaj viscosity nrog extrusion ua kub thiab shear tus nqi yuav ua rau kom poob sai sai, tus neeg siv tsuas yog yuav tsum tau kho lub extruder kub thiab ntsia hlau ceev, koj yuav ua tau zoo heev kev ua tau zoo ntawm hlau thiab cable khoom. Ntau cov ntawv thov hauv tsev thiab txawv teb chaws qhia tau hais tias, rau cov khoom siv uas tsis muaj pa halogen-dawb, vim tias qhov viscosity loj heev, yaj qhov Performance index tsawg dhau, yog li tsuas yog siv cov compression ratio ntawm cov ntsia hlau ( compression ratio tsawg dua. 1. 3) extrusion, txhawm rau xyuas kom zoo extrusion zoo. Roj hmab-raws li EVM cov ntaub ntawv nrog cov neeg ua haujlwm vulcanising tuaj yeem raug extruded ntawm ob qho tib si roj hmab extruders thiab cov hom phiaj dav dav extruders. Cov txheej txheem tom ntej vulcanisation (cross-linking) txheej txheem tuaj yeem ua los ntawm thermochemical (peroxide) cross-linking lossis los ntawm electron accelerator irradiation cross-linking.
2. 3 Yooj yim hloov kho thiab hloov kho
Cov hlau thiab cables nyob txhua qhov chaw, los ntawm ntuj mus rau hauv av, los ntawm roob mus rau hiav txwv. Cov neeg siv ntawm cov xaim thiab cable yuav tsum muaj ntau yam thiab coj txawv txawv, thaum cov qauv ntawm cov hlau thiab cable zoo sib xws, nws qhov kev ua tau zoo sib txawv yog qhov tseem ceeb hauv cov ntaub ntawv rwb thaiv tsev thiab cov ntaub npog npog.
Txog tam sim no, ob qho tib si hauv tsev thiab txawv teb chaws, mos PVC tseem suav rau feem coob ntawm cov ntaub ntawv polymer siv hauv kev lag luam cable. Txawm li cas los xij, nrog kev paub txog kev tiv thaiv ib puag ncig thiab kev txhim kho kom ruaj khov.
Cov ntaub ntawv PVC tau raug txwv zoo heev, cov kws tshawb fawb tau ua txhua yam ua tau los nrhiav lwm cov ntaub ntawv rau PVC, qhov zoo tshaj plaws uas yog EVA.
EVA tuaj yeem sib xyaw nrog ntau hom polymers, tab sis kuj muaj ntau yam ntawm cov hmoov ntxhia thiab cov khoom siv sib xyaw ua ke, cov khoom sib xyaw tuaj yeem ua rau hauv cov yas thermoplastic rau cov yas cables, tab sis kuj mus rau hauv cross-linked roj hmab rau cov roj hmab cables. Cov qauv tsim qauv tuaj yeem ua raws li cov neeg siv khoom (lossis tus qauv), EVA ua cov khoom siv hauv paus, ua kom cov khoom ua tau raws li qhov yuav tsum tau ua.
3 EVA daim ntawv thov ntau yam
3. 1 Siv los ua cov khoom siv tiv thaiv ib nrab rau cov hluav taws xob hluav taws xob siab
Raws li peb txhua tus paub, cov khoom siv tseem ceeb ntawm cov khoom siv tiv thaiv yog cov pa roj carbon dub, hauv cov khoom siv yas lossis roj hmab los ntxiv cov pa roj carbon ntau ntau yuav ua rau lub cev tsis zoo ntawm cov khoom siv tiv thaiv thiab qhov smoothness ntawm qib extrusion. Txhawm rau tiv thaiv qee qhov tso tawm hauv cov hluav taws xob hluav taws xob, cov ntaub thaiv sab hauv thiab sab nrauv yuav tsum nyias, ci, ci thiab sib xws. Piv nrog rau lwm cov polymers, EVA tuaj yeem ua qhov no yooj yim dua. Yog vim li cas rau qhov no yog tias EVA cov txheej txheem extrusion yog qhov tshwj xeeb zoo, ntws zoo, thiab tsis tuaj yeem yaj qhov tshwm sim tawg. Cov ntaub thaiv npog tau muab faib ua ob pawg: qhwv hauv cov neeg xyuas pib sab nraud hu ua cov ntaub thaiv npog sab hauv - nrog cov khoom siv sab hauv; qhwv nyob rau hauv lub rwb thaiv tsev sab nraud hu ua cov ntaub thaiv npog sab nrauv - nrog cov khoom siv sab nrauv; Cov khoom siv tshuaj ntsuam sab hauv feem ntau yog cov thermoplastic Cov khoom siv sab hauv feem ntau yog cov thermoplastic thiab feem ntau ua raws li EVA nrog VA cov ntsiab lus ntawm 18% mus rau 28%; Cov khoom siv sab nrauv feem ntau yog sib txuas thiab tev tau thiab feem ntau ua raws li EVA nrog VA cov ntsiab lus ntawm 40% mus rau 46%.
3. 2 Thermoplastic thiab cross-linked nplaim retardant fuels
Thermoplastic nplaim taws retardant polyolefin yog dav siv nyob rau hauv kev lag luam cable, feem ntau yog rau halogen los yog halogen-dawb cov kev cai ntawm marine cables, fais fab cables thiab high-qib kev tsim kho kab. Lawv lub sijhawm ua haujlwm ntev yog li ntawm 70 txog 90 ° C.
Rau nruab nrab thiab siab voltage fais fab cables ntawm 10 kV thiab saum toj no, uas muaj hluav taws xob kev ua tau zoo heev, cov nplaim retardant zog yog feem ntau yug los ntawm lub txheej sheath. Hauv qee qhov kev xav tau ib puag ncig cov tsev lossis cov haujlwm, cov cables yuav tsum muaj cov pa luam yeeb tsawg, tsis muaj halogen, tsis muaj tshuaj lom lossis tsis muaj pa luam yeeb thiab cov khoom siv halogen tsawg, yog li cov nplaim hluav taws kub retardant polyolefins yog cov tshuaj siv tau.
Rau qee lub hom phiaj tshwj xeeb, sab nraud txoj kab uas hla tsis loj, qhov kub tsis kam nyob rau hauv 105 ~ 150 ℃ ntawm cov cable tshwj xeeb, ntau cov khoom siv hluav taws xob txuas hluav taws xob polyolefin, nws txoj kab sib txuas tuaj yeem xaiv los ntawm cov chaw tsim khoom cable raws li lawv tus kheej cov khoom siv. , ob qho tib si cov tsoos high-pressure chav los yog high-temperature ntsev da dej, tab sis kuj muaj electron accelerator chav kub irradiation cross-linked txoj kev. Nws lub sijhawm ua haujlwm kub tau muab faib ua 105 ℃, 125 ℃, 150 ℃ peb cov ntaub ntawv, cov nroj tsuag tuaj yeem ua tau raws li cov kev cai sib txawv ntawm cov neeg siv lossis cov qauv, halogen-dawb lossis halogen-muaj roj teeb meem.
Nws paub zoo tias polyolefins tsis yog-polar lossis tsis muaj zog polar polar polymers. Raws li lawv zoo ib yam li cov roj ntxhia hauv polarity, polyolefins feem ntau suav hais tias yog cov roj tsis muaj zog raws li lub hauv paus ntsiab lus ntawm kev sib raug zoo. Txawm li cas los xij, ntau cov qauv hauv tsev thiab txawv teb chaws kuj tau hais tias cov kev sib txuas sib txuas yuav tsum muaj kev tiv thaiv zoo rau cov roj, cov kuab tshuaj thiab txawm tias cov roj slurries, acids thiab alkalis. Qhov no yog ib qho kev sib tw rau cov kws tshawb fawb cov ntaub ntawv, tam sim no, txawm nyob hauv Suav teb lossis txawv teb chaws, cov ntaub ntawv xav tau no tau tsim, thiab nws cov khoom siv yog EVA.
3. 3 Oxygen barrier khoom
Stranded multi-core cables muaj ntau qhov voids ntawm cov cores uas yuav tsum tau muab sau kom paub meej ib puag ncig cable zoo li, yog hais tias lub filling nyob rau hauv lub txheej sheath yog ua los ntawm halogen tsis muaj roj barrier. Cov txheej filling no ua raws li nplaim taws teeb meem (oxygen) thaum lub cable kub hnyiab thiab yog li hu ua "oxygen barrier" hauv kev lag luam.
Cov kev cai yooj yim rau cov khoom siv oxygen barrier yog: zoo extrusion zog, zoo halogen-dawb nplaim retardancy (oxygen index feem ntau saum 40) thiab tus nqi qis.
Cov pa oxygen barrier no tau siv dav hauv kev lag luam cable rau ntau tshaj kaum xyoo thiab tau ua rau muaj kev txhim kho tseem ceeb hauv cov nplaim hluav taws xob ntawm cov cables. Cov pa oxygen barrier tuaj yeem siv rau ob qho tib si halogen-dawb nplaim hluav taws-retardant cables thiab halogen-dawb nplaim hluav taws-retardant cables (xws li PVC). Ntau qhov kev xyaum tau pom tias cov cables uas muaj cov pa oxygen barrier feem ntau yuav dhau los ua ib qho kev sib tsoo thiab cov kev ntsuas kub.
Los ntawm qhov pom ntawm kev tsim cov khoom siv, cov khoom siv oxygen barrier no yog qhov "ultra-high muab tub lim", vim hais tias kom ua tau raws li tus nqi qis, nws yog ib qho tsim nyog yuav tsum tau siv lub siab muab tub lim, kom ua tiav cov pa oxygen siab yuav tsum tau ntxiv cov feem ntau. (2 mus rau 3 zaug) ntawm Mg (OH) 2 lossis Al (OH) 3, thiab kom extrude zoo thiab yuav tsum xaiv EVA ua cov khoom siv hauv paus.
3. 4 Hloov kho PE sheathing khoom
Polyethylene sheathing cov ntaub ntawv yog feem ntau ua rau ob qho teeb meem: ua ntej, lawv nquag yaj tawg (xws li sharkskin) thaum extrusion; Thib ob, lawv muaj feem xyuam rau ib puag ncig kev ntxhov siab tawg. Qhov kev daws teeb meem yooj yim tshaj plaws yog ntxiv ib qho kev faib ua feem ntawm EVA hauv kev tsim. siv raws li kev hloov kho EVA feem ntau siv VA cov ntsiab lus qis ntawm qib, nws qhov Performance index ntawm 1 txog 2 yog qhov tsim nyog.
4. Kev cia siab rau kev txhim kho
(1) EVA tau siv dav hauv kev lag luam cable, tus nqi txhua xyoo hauv kev loj hlob zuj zus thiab ruaj khov. Tshwj xeeb tshaj yog nyob rau hauv kaum xyoo dhau los, vim qhov tseem ceeb ntawm kev tiv thaiv ib puag ncig, EVA-raws li roj tsis kam tau muaj kev loj hlob sai, thiab tau hloov ib nrab ntawm PVC-raws li cov khoom siv cable sib txawv. Nws cov nqi zoo heev thiab kev ua tau zoo ntawm cov txheej txheem extrusion yog qhov nyuaj los hloov lwm yam ntaub ntawv.
(2) cable kev lag luam txhua xyoo noj ntawm EVA resin ze li ntawm 100,000 tons, kev xaiv ntawm EVA resin ntau yam, VA cov ntsiab lus los ntawm qis mus rau siab yuav raug siv, ua ke nrog cov khoom siv cable granulation enterprise loj tsis loj, kis tau rau hauv txhua lub lag luam txhua xyoo. tsuas yog nyob rau hauv ntau txhiab tons ntawm EVA resin nce thiab nqis, thiab yog li yuav tsis yog EVA kev lag luam kev lag luam loj heev mloog. Piv txwv li, qhov loj tshaj plaws ntawm halogen-dawb nplaim hluav taws kub retardant puag khoom, lub ntsiab xaiv ntawm VA / MI = 28 / 2 ~ 3 ntawm EVA resin (xws li US DuPont's EVA 265 # ). Thiab qhov kev qhia tshwj xeeb ntawm EVA txog tam sim no tsis muaj cov tuam txhab tsim khoom tsim khoom thiab muab khoom. Tsis txhob hais txog VA cov ntsiab lus siab dua 28, thiab yaj qhov ntsuas tsawg dua 3 ntawm lwm yam EVA resin ntau lawm thiab muab khoom.
(3) cov tuam txhab txawv teb chaws tsim EVA vim tias tsis muaj cov neeg sib tw hauv tsev, thiab tus nqi tau ntev ntev, ua rau muaj kev kub ntxhov rau kev cog qoob loo hauv tsev. ntau tshaj 50% ntawm VA cov ntsiab lus ntawm roj hmab-hom EVM, yog ib lub tuam txhab txawv teb chaws dominated, thiab tus nqi zoo ib yam li VA cov ntsiab lus ntawm hom 2 mus rau 3 zaug. Xws li cov nqi siab, nyob rau hauv lem, kuj cuam tshuam tus nqi ntawm no roj hmab hom EVM, yog li cov cable kev lag luam hu rau domestic EVA manufacturers, los txhim kho tus nqi ntawm domestic ntau lawm EVA. Kev tsim khoom ntau ntawm kev lag luam tau siv ntau ntawm EVA resin.
(4) Relying ntawm nthwv dej ntawm ib puag ncig kev tiv thaiv nyob rau hauv lub era ntawm globalization, EVA raug suav hais tias los ntawm kev lag luam cable los ua cov khoom siv zoo tshaj plaws rau kev tiv thaiv ib puag ncig. Kev siv EVA tau loj hlob ntawm tus nqi ntawm 15% hauv ib xyoos thiab qhov kev cia siab zoo heev. Tus nqi thiab kev loj hlob ntawm cov ntaub thaiv npog thiab nruab nrab thiab siab voltage fais fab cable ntau lawm thiab kev loj hlob tus nqi, li 8% mus rau 10% ntawm; polyolefin resistances tau loj hlob sai, nyob rau hauv xyoo tas los no tseem nyob ntawm 15% mus rau 20% ntawm, thiab nyob rau hauv lub zeem muag tom ntej 5 mus rau 10 xyoo, kuj tseem yuav tswj tau qhov kev loj hlob no.
Post lub sij hawm: Lub Xya hli ntuj-31-2022