1. Gabatarwa
EVA ita ce taƙaitaccen bayani ga ethylene vinyl acetate copolymer, wani polymer na polyolefin. Saboda ƙarancin zafin narkewarsa, kyakkyawan ruwa, polarity da abubuwan da ba halogen ba, kuma yana iya dacewa da nau'ikan polymers da foda ma'adinai, da dama daga cikin kaddarorin injiniya da na zahiri, halayen lantarki da daidaiton aikin sarrafawa, kuma farashin bai yi yawa ba, wadatar kasuwa ta isa, don haka duka a matsayin kayan rufin kebul, ana iya amfani da shi azaman kayan cikawa, kayan rufewa; ana iya yin shi azaman kayan thermoplastic, kuma ana iya yin shi azaman kayan haɗin thermosetting.
Ana iya amfani da nau'ikan EVA iri-iri, tare da masu hana harshen wuta, a matsayin shingen mai mara hayaki ko halogen; zaɓi babban abun ciki na VA na EVA a matsayin kayan tushe kuma ana iya yin shi azaman kayan da ke jure mai; zaɓi ma'aunin narkewa na matsakaicin EVA, ƙara sau 2 zuwa 3 na cika masu hana harshen wuta na EVA da za a iya yi don aikin fitar da iskar oxygen da farashin kayan cikawa mafi daidaito.
A cikin wannan takarda, daga halayen tsarin EVA, gabatar da aikace-aikacensa a masana'antar kebul da kuma ci gaban da ake samu.
2. Sifofin gini
Lokacin samar da haɗin kai, canza rabon digirin polymerization n / m na iya samar da abun ciki na VA daga 5 zuwa 90% na EVA; ƙara jimlar digirin polymerization na iya samar da nauyin kwayoyin halitta daga dubun dubbai zuwa ɗaruruwan dubban EVA; abun ciki na VA ƙasa da 40%, saboda kasancewar ɓangaren kristal, ƙarancin sassauci, wanda aka fi sani da filastik EVA; lokacin da abun ciki na VA ya fi 40%, elastomer mai kama da roba ba tare da kristal ba, ana kiransa da robar EVM.
1. 2 Kadara
Sarkar kwayoyin halitta ta EVA tsari ne mai cikakken tsari, don haka yana da kyakkyawan tsufa na zafi, yanayi da juriya ga ozone.
Babban sarkar kwayoyin EVA ba ta ƙunshi haɗin gwiwa biyu, zoben benzene, acyl, ƙungiyoyin amine da sauran ƙungiyoyi masu sauƙin shan taba lokacin ƙonewa, sarƙoƙi na gefe kuma ba su ƙunshi sauƙin shan taba lokacin ƙona methyl, phenyl, cyano da sauran ƙungiyoyi ba. Bugu da ƙari, ƙwayar kanta ba ta ƙunshi abubuwan halogen ba, don haka ya dace musamman ga tushen mai mai juriya na halogen mara hayaƙi.
Babban girman rukunin vinyl acetate (VA) a cikin sarkar gefen EVA da matsakaicin ƙarfinsa yana nufin cewa duka biyun yana hana yanayin ƙashin bayan vinyl na crystallize da kuma haɗuwa da ma'adanai masu cika ma'adinai, wanda ke haifar da yanayin man fetur mai ƙarfi. Wannan gaskiya ne musamman ga ƙarancin hayaki da juriya mara halogen, saboda dole ne a ƙara masu hana harshen wuta waɗanda ke da fiye da kashi 50% na abun ciki na girma [misali Al(OH) 3, Mg(OH) 2, da sauransu] don cika buƙatun ƙa'idodin kebul don hana harshen wuta. Ana amfani da EVA mai matsakaicin zuwa babban abun ciki na VA a matsayin tushe don samar da ƙarancin hayaki da man fetur mai hana harshen wuta mara halogen tare da kyawawan halaye.
Ganin cewa ƙungiyar EVA ta vinyl acetate (VA) tana da ƙarfi sosai, yawan sinadarin VA da ke cikinta, yawan sinadarin polymer da ke cikinta yana da ƙarfi sosai, kuma mafi kyawun juriyar mai. Juriyar mai da masana'antar kebul ke buƙata galibi tana nufin ikon jurewa man ma'adinai marasa ƙarfi ko marasa ƙarfi. Dangane da ƙa'idar irin wannan jituwa, ana amfani da EVA mai yawan sinadarin VA a matsayin kayan tushe don samar da shingen mai mara hayaki da halogen mai mai kyau tare da kyakkyawan juriyar mai.
Kwayoyin EVA a cikin aikin atom na H alpha-olefin sun fi aiki, a cikin radicals na peroxide ko tasirin electron-radiation mai ƙarfi yana da sauƙin ɗaukar H cross-linking reaction, ya zama filastik mai haɗin giciye ko roba, ana iya yin buƙatun aiki na musamman na waya da kayan kebul.
Ƙara rukunin vinyl acetate yana sa zafin narkewar EVA ya ragu sosai, kuma adadin sarƙoƙin gefen VA na iya sa kwararar EVA ta ƙaru. Saboda haka, aikin fitar da shi ya fi tsarin ƙwayoyin polyethylene iri ɗaya kyau, yana zama kayan tushe da aka fi so don kayan kariya na semi-conductive da shingen mai mara halogen da halogen.
2 Fa'idodin samfur
2. 1 Aiki mai tsada sosai
Halayen zahiri da na inji na EVA, juriyar zafi, juriyar yanayi, juriyar ozone, da kuma halayen lantarki suna da kyau sosai. Zaɓi matakin da ya dace, ana iya yin shi da juriyar zafi, aikin hana harshen wuta, amma kuma yana iya zama mai, kayan kebul na musamman masu jure wa narkewa.
Ana amfani da kayan EVA na Thermoplastic galibi tare da abun ciki na VA na 15% zuwa 46%, tare da ma'aunin narkewa na maki 0.5 zuwa 4. EVA tana da masana'antun da yawa, samfuran iri da yawa, zaɓuɓɓuka iri-iri, farashi mai matsakaici, wadatar wadata, masu amfani kawai suna buƙatar buɗe ɓangaren EVA na gidan yanar gizon, alamar, aiki, farashi, wurin isarwa a kallo ɗaya, zaku iya zaɓa, mai dacewa sosai.
EVA polymer ne na polyolefin, daga laushi da amfani da kwatancen aiki, kuma kayan polyethylene (PE) da kayan kebul na polyvinyl chloride (PVC) masu laushi suna kama da juna. Amma ƙarin bincike, za ku sami EVA da nau'ikan kayan guda biyu da ke sama idan aka kwatanta su da fifikon da ba za a iya maye gurbinsu ba.
2. 2 kyakkyawan aikin sarrafawa
EVA a cikin aikace-aikacen kebul yana fitowa ne daga kayan kariya na kebul na matsakaici da babban ƙarfin lantarki a ciki da wajen farko, daga baya kuma ya faɗaɗa zuwa shingen mai mara halogen. Waɗannan nau'ikan kayan guda biyu daga mahangar sarrafawa ana ɗaukar su a matsayin "kayan da aka cika sosai": kayan kariya saboda buƙatar ƙara adadi mai yawa na baƙin carbon mai sarrafawa da kuma ƙara ɗanɗanonsa, ruwan sha yana raguwa sosai; man fetur mara halogen mai hana harshen wuta yana buƙatar ƙara adadi mai yawa na masu hana harshen wuta mara halogen, haka nan ɗanɗano na kayan mara halogen ya ƙaru sosai, ruwan sha yana raguwa sosai. Mafita ita ce a nemo polymer wanda zai iya ɗaukar manyan allurai na cikawa, amma kuma yana da ƙarancin ɗanɗano na narkewa da kuma kyakkyawan ruwa. Saboda wannan dalili, EVA ita ce zaɓin da aka fi so.
Danko na narkewar EVA tare da zafin sarrafa fitarwa da ƙimar yankewa zai ƙara raguwa cikin sauri, mai amfani yana buƙatar daidaita zafin fitarwa da saurin sukurori kawai, zaku iya yin kyakkyawan aiki na samfuran waya da kebul. Yawancin aikace-aikacen cikin gida da na ƙasashen waje sun nuna cewa, ga kayan da ba su da hayaki mai ƙarancin halogen, saboda ɗanko ya yi yawa, ma'aunin narkewa ya yi ƙanƙanta, don haka kawai amfani da sukurori mai ƙarancin matsi (rabo na matsi na ƙasa da 1.3) fitarwa, don tabbatar da ingancin fitarwa mai kyau. Ana iya fitar da kayan EVM na roba tare da wakilai na vulcanizing akan masu fitar da roba da masu fitar da fitarwa na gabaɗaya. Ana iya aiwatar da tsarin vulcanization (haɗin giciye) na gaba ko dai ta hanyar haɗa thermochemical (peroxide) haɗin giciye ko ta hanyar haɗa haske mai saurin lantarki.
2. 3 Mai sauƙin gyarawa da daidaitawa
Wayoyi da kebul suna ko'ina, daga sama zuwa ƙasa, daga tsaunuka zuwa teku. Masu amfani da buƙatun waya da kebul suma suna da bambanci kuma abin mamaki, yayin da tsarin waya da kebul iri ɗaya ne, bambance-bambancen aikinsu galibi suna bayyana ne a cikin kayan rufewa da rufin rufi.
Zuwa yanzu, a gida da waje, PVC mai laushi har yanzu yana da mafi yawan kayan polymer da ake amfani da su a masana'antar kebul. Duk da haka, tare da ƙara wayar da kan jama'a game da kare muhalli da ci gaba mai ɗorewa.
An takaita kayan PVC sosai, masana kimiyya suna yin duk mai yiwuwa don nemo wasu kayan da za su maye gurbin PVC, wanda mafi kyau daga cikinsu shine EVA.
Ana iya haɗa EVA da nau'ikan polymers iri-iri, amma kuma tare da nau'ikan foda na ma'adinai da kayan aikin sarrafawa masu dacewa, samfuran da aka haɗa za a iya yin su zuwa filastik thermoplastic don kebul na filastik, amma kuma zuwa roba mai haɗin gwiwa don kebul na roba. Masu tsara ƙira na iya dogara ne akan buƙatun mai amfani (ko na yau da kullun), EVA a matsayin kayan tushe, don yin aikin kayan don biyan buƙatun.
Jerin aikace-aikacen EVA guda 3
3. 1 Ana amfani da shi azaman kayan kariya na rabin-gudanarwa don kebul na wutar lantarki mai ƙarfin lantarki mai ƙarfi
Kamar yadda muka sani, babban kayan kariya shine carbon baki mai aiki, a cikin kayan filastik ko tushen roba don ƙara yawan carbon baki zai lalata ruwan kayan kariya da kuma santsi na matakin fitarwa. Don hana fitar da wasu abubuwa a cikin kebul masu ƙarfin lantarki, garkuwar ciki da ta waje dole ne su kasance siriri, masu sheƙi, masu haske da kuma iri ɗaya. Idan aka kwatanta da sauran polymers, EVA na iya yin hakan cikin sauƙi. Dalilin haka shine tsarin fitar da EVA yana da kyau musamman, kwarara mai kyau, kuma ba ya saurin narkewar fashewar abu. An raba kayan kariya zuwa rukuni biyu: an naɗe shi a cikin mai gudanarwa a waje da ake kira garkuwar ciki - tare da kayan allo na ciki; an naɗe shi a cikin mai rufi a waje da ake kira garkuwar waje - tare da kayan allo na waje; kayan allo na ciki galibi thermoplastic ne. Kayan allo na ciki galibi thermoplastic ne kuma galibi yana dogara ne akan EVA tare da abun ciki na VA na 18% zuwa 28%; kayan allo na waje galibi suna da alaƙa da juna kuma ana iya cire su kuma galibi ana dogara ne akan EVA tare da abun ciki na VA na 40% zuwa 46%.
3. 2 Man fetur masu hana harshen wuta da kuma masu hana harshen wuta
Ana amfani da polyolefin mai hana harshen wuta a masana'antar kebul, musamman don buƙatun halogen ko halogen na kebul na ruwa, kebul na wutar lantarki da layukan gini masu inganci. Yanayin aikinsu na dogon lokaci yana tsakanin 70 zuwa 90 °C.
Ga kebul na wutar lantarki mai matsakaicin ƙarfi da ƙarfin lantarki mai ƙarfin 10 kV zuwa sama, waɗanda ke da buƙatun aikin lantarki mai yawa, halayen hana harshen wuta galibi suna da alaƙa da murfin waje. A wasu gine-gine ko ayyuka masu buƙatar muhalli, ana buƙatar kebul ɗin su kasance suna da ƙarancin hayaki, marasa halogen, ƙarancin guba ko ƙarancin hayaki da ƙarancin halogen, don haka polyolefins masu hana harshen wuta na thermoplastic mafita ce mai kyau.
Don wasu dalilai na musamman, diamita na waje ba shi da girma, juriyar zafin jiki a cikin 105 ~ 150 ℃ tsakanin kebul na musamman, kayan polyolefin masu hana harshen wuta masu haɗin giciye, masana'antar kebul na iya zaɓar haɗin giciye bisa ga yanayin samarwarsu, duka na gargajiya mai tururi mai ƙarfi ko wanka mai zafi mai zafi, amma kuma akwai hanyar hasken wutar lantarki mai saurin ɗagawa ta ɗakin. Zafin aikin sa na dogon lokaci an raba shi zuwa fayiloli uku 105 ℃, 125 ℃, 150 ℃, ana iya yin masana'antar samarwa bisa ga buƙatun masu amfani daban-daban ko ƙa'idodi, shingen mai mara halogen ko mai ɗauke da halogen.
An san cewa polyolefins ba su da polar ko kuma suna da rauni a polar polar polymers. Ganin cewa suna kama da man ma'adinai a polarity, galibi ana ɗaukar polyolefins a matsayin waɗanda ba su da juriya ga mai bisa ga ƙa'idar jituwa iri ɗaya. Duk da haka, yawancin ƙa'idodin kebul a cikin gida da waje sun kuma ƙayyade cewa juriyar haɗin gwiwa dole ne su kasance suna da kyakkyawan juriya ga mai, abubuwan narkewa har ma da slurries na mai, acid da alkalis. Wannan ƙalubale ne ga masu bincike na kayan abu, yanzu, ko a China ko a ƙasashen waje, an ƙirƙiri waɗannan kayan da ke buƙatar aiki, kuma kayan sa na asali sune EVA.
3. 3 Kayan shingen iskar oxygen
Kebulan da aka ɗaure da manyan core suna da ramuka da yawa tsakanin core waɗanda ke buƙatar a cike su don tabbatar da bayyanar kebul mai zagaye, idan cikawar da ke cikin murfin waje an yi ta ne da shingen mai mara halogen. Wannan matakin cikawa yana aiki azaman shingen wuta (oxygen) lokacin da kebul ɗin ya ƙone kuma saboda haka ana kiransa da "shingen shamaki" a masana'antar.
Abubuwan da ake buƙata don kayan shingen iskar oxygen sune: kyawawan kaddarorin fitarwa, ingantaccen hana harshen wuta mara halogen (ƙimar iskar oxygen yawanci sama da 40) da ƙarancin farashi.
An yi amfani da wannan shingen iskar oxygen sosai a masana'antar kebul fiye da shekaru goma kuma ya haifar da gagarumin ci gaba a cikin jinkirin wuta na kebul. Ana iya amfani da shingen iskar oxygen don kebul na hana wuta mara halogen da kebul na hana wuta mara halogen (misali PVC). Yawancin gwaje-gwaje sun nuna cewa kebul masu shingen iskar oxygen sun fi yiwuwa su wuce gwaje-gwajen ƙonewa a tsaye da kuma ƙonewa a cikin ƙulle.
Daga mahangar hada kayan abu, wannan kayan kariya daga iskar oxygen a zahiri "cikakken abu ne mai matuƙar girma", domin domin biyan ƙarancin farashi, ya zama dole a yi amfani da babban cika, don cimma babban ma'aunin iskar oxygen dole ne a ƙara babban rabo (sau 2 zuwa 3) na Mg (OH) 2 ko Al (OH) 3, kuma don fitar da mai kyau kuma dole ne a zaɓi EVA a matsayin kayan tushe.
3. 4 Kayan gyaran murfin PE
Kayan da ke rufe murfin polyethylene suna fuskantar matsaloli guda biyu: na farko, suna iya narkewar karyewa (misali fatar shark) yayin fitar da ruwa; na biyu, suna iya kamuwa da tsagewar damuwa ta muhalli. Mafi sauƙi mafita ita ce a ƙara wani rabo na EVA a cikin tsarin. Ana amfani da shi azaman EVA da aka gyara galibi ta amfani da ƙarancin abun ciki na VA na matakin, ma'aunin narkewar sa zuwa tsakanin 1 zuwa 2 ya dace.
4. Masu hangen nesa na ci gaba
(1) An yi amfani da EVA sosai a masana'antar kebul, adadin da ake samu a kowace shekara a cikin ci gaba a hankali da kuma ci gaba. Musamman a cikin shekaru goma da suka gabata, saboda mahimmancin kariyar muhalli, juriyar mai ta hanyar EVA ta kasance ci gaba mai sauri, kuma ta maye gurbin yanayin kayan kebul na PVC. Kyakkyawan aikinta na farashi mai kyau da kyakkyawan aikinta na tsarin fitarwa yana da wuya a maye gurbin duk wani abu.
(2) yawan amfani da resin EVA na shekara-shekara na masana'antar kebul kusan tan 100,000, zaɓin nau'ikan resin EVA, abun ciki na VA daga ƙasa zuwa babba za a yi amfani da shi, tare da girman kayan kebul ba shi da yawa, ana yaɗa shi a kowace kamfani kowace shekara a cikin dubban tan na resin EVA sama da ƙasa, don haka ba zai zama babban abin jan hankali ga masana'antar EVA ba. Misali, mafi girman adadin kayan tushe na resin EVA mara halogen, babban zaɓi na VA / MI = 28 /2 ~ 3 na resin EVA (kamar EVA 265 ta Amurka ta DuPont). Kuma wannan matakin ƙayyadaddun EVA zuwa yanzu babu masana'antun cikin gida da za a samar da kuma samarwa. Ba tare da ambaton abun ciki na VA sama da 28 ba, da kuma ma'aunin narkewa ƙasa da 3 na sauran samarwa da samarwa na resin EVA.
(3) kamfanonin ƙasashen waje da ke samar da EVA saboda babu masu fafatawa a cikin gida, kuma farashin ya daɗe yana da tsada, wanda hakan ya danne sha'awar samar da kebul na cikin gida. Fiye da kashi 50% na abubuwan da ke cikin VA na EVM na roba, kamfani ne na ƙasashen waje da ke mamaye, kuma farashin yana kama da abubuwan da ke cikin VA na alamar sau 2 zuwa 3. Irin waɗannan farashi masu tsada, bi da bi, suna shafar adadin wannan nau'in roba EVM, don haka masana'antar kebul na kira ga masana'antun EVA na cikin gida, da su inganta yawan samar da EVA na cikin gida. Ƙarin samar da masana'antar ya kasance amfani da resin EVA sosai.
(4) Dangane da yanayin kariyar muhalli a zamanin dunkulewar duniya, masana'antar kebul na ɗaukar EVA a matsayin mafi kyawun kayan tushe don juriya ga mai mara muhalli. Amfani da EVA yana ƙaruwa da kashi 15% a kowace shekara kuma hasashen yana da matuƙar kyau. Adadin da ƙimar girma na kayan kariya da samar da kebul na wutar lantarki mai matsakaicin ƙarfi da babban ƙarfin lantarki da ƙimar girma, kusan kashi 8% zuwa 10% tsakanin; juriyar polyolefin suna ƙaruwa da sauri, a cikin 'yan shekarun nan sun kasance a tsakanin kashi 15% zuwa 20% tsakanin, kuma a cikin shekaru 5 zuwa 10 masu zuwa, ana iya ci gaba da wannan ƙimar girma.
Lokacin Saƙo: Yuli-31-2022