1. Gabatarwa
EVA shine gajartawar ethylene vinyl acetate copolymer, polymer polyolefin. Saboda ƙananan zafin jiki na narkewa, ruwa mai kyau, polarity da abubuwan da ba halogen ba, kuma zai iya dacewa da nau'ikan polymers da foda na ma'adinai, adadin kayan aikin injiniya da na jiki, kayan lantarki da ma'auni na aiki, kuma farashin ba shi da kyau. high, da kasuwar wadata ya isa, don haka duka biyu a matsayin na USB rufi abu, kuma za a iya amfani da matsayin filler, sheathing abu; za a iya sanya shi a cikin kayan aikin thermoplastic, kuma ana iya sanya shi cikin kayan haɗin giciye na thermosetting.
EVA fadi da kewayon amfani, tare da harshen wuta retardants, za a iya sanya a cikin low hayaki-free halogen ko halogen man fetur shinge; zaɓi babban abun ciki na VA na EVA azaman kayan tushe kuma ana iya sanya shi cikin kayan da ke jurewa mai; zaɓi ma'aunin narkewa na EVA mai matsakaici, ƙara 2 zuwa sau 3 na cikawar EVA wuta retardants za a iya sanya shi zuwa aikin aiwatar da extrusion da farashin madaidaicin shingen iskar oxygen (cika) abu.
A cikin wannan takarda, daga kaddarorin tsarin EVA, gabatarwar aikace-aikacen sa a cikin masana'antar kebul da haɓaka haɓaka.
2. Tsarin Properties
Lokacin samar da kira, canza rabon digiri na polymerisation n / m na iya samar da abun ciki na VA daga 5 zuwa 90% na EVA; ƙara yawan digiri na polymerisation zai iya samar da nauyin kwayoyin halitta daga dubun dubatar zuwa daruruwan dubban EVA; Abubuwan VA da ke ƙasa da 40%, saboda kasancewar ɓangaren crystallisation, ƙarancin elasticity, wanda aka fi sani da filastik EVA; lokacin da abun ciki na VA ya fi 40%, roba mai kama da elastomer ba tare da crystallisation ba, an fi sani da EVM rubber.
1.2 Properties
Sarkar kwayoyin halitta na EVA cikakken tsari ne na linzamin kwamfuta, don haka yana da kyakkyawan tsufa na zafi, yanayi da juriya na ozone.
EVA molecule main sarkar ba ya ƙunshi biyu bonds, benzene zobe, acyl, amine kungiyoyin da sauran kungiyoyin sauki shan taba lokacin kona, gefe sarƙoƙi kuma ba ya dauke da sauki shan taba lokacin kona methyl, phenyl, cyano da sauran kungiyoyin. Bugu da kari, kwayoyin da kanta ba ta ƙunshi abubuwan halogen ba, don haka ya dace musamman ga ƙananan hayaƙi mara ƙarfi na halogen mara ƙarfi.
Girman girman rukunin vinyl acetate (VA) a cikin sarkar gefen EVA da matsakaiciyar matsakaiciyar sa yana nufin cewa duka biyun sun hana yanayin kashin bayan vinyl don yin crystallize da ma'aurata da kyau tare da masu cika ma'adinai, wanda ke haifar da yanayi don haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓaka haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar haɓakar ma'aurata da ma'aurata da kyau tare da ma'adinan ma'adinai. Wannan gaskiya ne musamman ga ƙananan hayaki da juriya marasa halogen, kamar yadda masu ɗaukar harshen wuta tare da abun ciki sama da 50% [misali Al (OH) 3, Mg (OH) 2, da sauransu] dole ne a ƙara don biyan buƙatun ma'aunin kebul. don jinkirin wuta. Ana amfani da EVA tare da matsakaici zuwa babban abun ciki na VA azaman tushe don samar da ƙananan hayaki da ƙarancin wuta mai hana halogen tare da kyawawan kaddarorin.
Kamar yadda ƙungiyar EVA gefen sarkar vinyl acetate (VA) ta zama iyakacin duniya, mafi girman abun ciki na VA, mafi girman iyakacin iyaka da polymer shine mafi kyawun juriya mai. Juriyar mai da masana'antar kebul ke buƙata galibi tana nufin iya jurewa mai ma'adinai mara ƙarfi ko rauni. Bisa ga ka'idar dacewa irin wannan, EVA tare da babban abun ciki na VA ana amfani dashi azaman kayan tushe don samar da ƙananan hayaki da shingen man fetur maras halogen tare da kyakkyawan juriya na man fetur.
Kwayoyin EVA a cikin alpha-olefin H atom wasan kwaikwayon ya fi aiki, a cikin radicals peroxide ko high-makamashi electron-radiation sakamako yana da sauƙi don ɗaukar halayen haɗin haɗin H, ya zama filastik mai haɗin gwiwa ko roba, ana iya yin buƙatun buƙatun aiki. na musamman waya da na USB kayan.
Bugu da ƙari na ƙungiyar vinyl acetate yana sa zafin narke na Eva ya ragu sosai, kuma adadin gajeren sassan VA na iya haifar da haɓakar EVA. Sabili da haka, aikinsa na extrusion yana da kyau fiye da tsarin kwayoyin halitta na irin wannan polyethylene, ya zama kayan da aka fi so don kayan kariya na wucin gadi da halogen da shingen man fetur marasa halogen.
2 Amfanin samfur
2. 1 Matsanancin tsadar kayan aiki
Kayan aikin EVA na zahiri da na inji, juriya na zafi, juriyar yanayi, juriya na ozone, kaddarorin lantarki suna da kyau sosai. Select da dace sa, za a iya sanya zafi juriya, harshen retardant yi, amma kuma mai, sauran ƙarfi-resistant na USB abu na musamman.
Ana amfani da kayan Thermoplastic EVA galibi tare da abun ciki na VA na 15% zuwa 46%, tare da ma'aunin narkewa na maki 0. 5 zuwa 4. EVA yana da masana'antun da yawa, nau'o'i da yawa, zaɓuɓɓuka masu yawa, matsakaicin farashi, wadataccen wadata, masu amfani kawai suna buƙatar buɗe sashin EVA na gidan yanar gizon, alamar, aiki, farashi, wurin bayarwa a kallo, za ku iya zaɓar, sosai. dace.
EVA shine polyolefin polyolefin, daga laushi da amfani da kwatancen aiki, da polyethylene (PE) abu da kuma polyvinyl chloride mai laushi (PVC) na USB abu yayi kama. Amma ƙarin bincike, zaku sami EVA da nau'ikan abu biyu na sama idan aka kwatanta da fifikon da ba za a iya maye gurbinsu ba.
2.2 kyakkyawan aikin sarrafawa
EVA a cikin aikace-aikacen kebul ɗin yana daga matsakaici da babban ƙarfin wuta na kebul na kariya abu a ciki da wajen farkon, kuma daga baya an shimfiɗa shi zuwa shingen mai marar halogen. Wadannan nau'ikan kayan guda biyu daga wurin sarrafawa ana ɗaukar su "kayan cike da kayan abinci saboda buƙatar ƙara yawan ƙwayar carbon da kuma sanya kariyar ta karu, da ruwa ya ragu sosai; Halogen-free harshen retardant man fetur bukatar ƙara yawan adadin halogen-free harshen retardants, kuma halogen-free danko abu ya karu sosai, da ruwa ya ragu sosai. Maganin shine a nemo polymer wanda zai iya ɗaukar manyan allurai na filler, amma kuma yana da ƙarancin narkewa da ruwa mai kyau. Saboda wannan dalili, EVA shine zaɓin da aka fi so.
EVA narke danko tare da extrusion aiki zafin jiki da karfi kudi zai kara da m raguwa, mai amfani kawai bukatar daidaita extruder zafin jiki da dunƙule gudun, za ka iya yin kyau kwarai yi na waya da na USB kayayyakin. A babban adadin gida da kuma kasashen waje aikace-aikace nuna cewa, ga sosai cika low hayaki halogen-free abu, saboda danko ne ma babba, narke index ne ma kananan, don haka kawai da amfani da low matsawa rabo dunƙule (matsi rabo na kasa da 1. 3) extrusion, domin tabbatar da kyau extrusion ingancin. Ana iya fitar da kayan EVM na tushen roba tare da ma'aikatan vulcanising akan duka masu fitar da roba da masu fitar da manufa ta gaba ɗaya. Za'a iya aiwatar da tsarin vulcanisation na gaba (giciye-haɗin kai) ko dai ta hanyar haɗe-haɗe na thermochemical (peroxide) ko ta hanyar haɗin kai da iska mai ƙarfi na lantarki.
2. 3 Sauƙi don gyarawa da daidaitawa
Wayoyi da igiyoyi suna ko'ina, tun daga sama zuwa kasa, daga tsaunuka zuwa teku. Masu amfani da buƙatun waya da na kebul suma sun bambanta da ban mamaki, yayin da tsarin waya da na USB yayi kama da haka, bambance-bambancen aikin sa yana nunawa a cikin kayan rufewa da sutura.
Ya zuwa yanzu, a gida da waje, PVC mai laushi har yanzu yana lissafin yawancin kayan polymer da ake amfani da su a cikin masana'antar kebul. Koyaya, tare da karuwar wayar da kan kariyar muhalli da ci gaba mai dorewa.
Abubuwan PVC an iyakance su sosai, masana kimiyya suna yin duk abin da zai yiwu don nemo madadin kayan zuwa PVC, wanda ya fi dacewa shine EVA.
Ana iya haɗa EVA tare da nau'ikan polymers, amma kuma tare da nau'ikan foda na ma'adinai da kayan aiki masu dacewa, samfuran da aka haɗa za a iya yin su a cikin filastik thermoplastic don igiyoyi na filastik, amma kuma cikin roba mai haɗin gwiwa don igiyoyi na roba. Zane-zanen ƙira na iya dogara ne akan buƙatun mai amfani (ko daidaitattun), EVA a matsayin kayan tushe, don yin aikin kayan don biyan buƙatun.
3 kewayon aikace-aikacen Eva
3. 1 An yi amfani da shi azaman kayan kariya mai ɗaukar nauyi don igiyoyin wutar lantarki mai ƙarfi
Kamar yadda muka sani, babban abu na garkuwar abu ne conductive carbon baki, a cikin roba ko roba tushe abu don ƙara wani babban adadin carbon baki zai tsanani deteriority da fluidity na garkuwa abu da kuma santsi na extrusion matakin. Don hana fitar da wani sashi a cikin manyan igiyoyi masu ƙarfin lantarki, garkuwar ciki da na waje dole ne su zama bakin ciki, mai sheki, mai haske da kuma ɗari ɗaya. Idan aka kwatanta da sauran polymers, EVA na iya yin hakan cikin sauƙi. Dalilin haka shi ne cewa tsarin extrusion na EVA yana da kyau musamman, mai kyau mai kyau, kuma ba shi da wuyar narke sabon abu. Kayan kariya ya kasu kashi biyu: an nannade shi a cikin madubi a waje da ake kira garkuwar ciki - tare da kayan allo na ciki; an nannade shi a cikin rufin waje da ake kira garkuwar waje - tare da kayan allo na waje; Abun allo na ciki shine mafi yawan thermoplastic Kayan allo na ciki shine mafi yawan thermoplastic kuma galibi yana dogara ne akan EVA tare da abun ciki na VA na 18% zuwa 28%; kayan allo na waje galibi suna haɗe-haɗe da peelable kuma galibi suna dogara ne akan EVA tare da abun ciki na VA na 40% zuwa 46%.
3. 2 Thermoplastic da giciye-linked harshen retardant man fetur
Thermoplastic harshen retardant polyolefin ana amfani da ko'ina a cikin na USB masana'antu, yafi ga halogen ko halogen-free bukatun na marine igiyoyi, ikon igiyoyi da high-sa yi layukan. Zafinsu na aiki na dogon lokaci yana daga 70 zuwa 90 ° C.
Don matsakaita da manyan igiyoyin wutar lantarki na 10 kV da sama, waɗanda ke da buƙatun aikin wutar lantarki sosai, abubuwan da ke hana wuta galibi suna ɗaukar su ta wurin kwasfa na waje. A cikin wasu gine-gine masu buƙatar muhalli ko ayyuka, ana buƙatar igiyoyi don samun ƙananan hayaki, marasa halogen, ƙananan guba ko ƙananan hayaki da ƙananan kaddarorin halogen, don haka polyolefins na wutar lantarki na thermoplastic shine mafita mai dacewa.
Don wasu dalilai na musamman, diamita na waje ba babba ba ne, juriya na zafin jiki a cikin 105 ~ 150 ℃ tsakanin kebul na musamman, ƙarin kayan haɗin wuta mai ƙera polyolefin, ana iya zaɓar haɗin haɗin kebul ɗin ta hanyar masana'anta ta USB bisa ga yanayin samar da nasu. , Dukan gargajiya high-matsi tururi ko high-zazzabi gishiri wanka, amma kuma samuwa electron totur dakin zafin jiki sakawa a haɗe hanya. Yawan zafin jiki na aiki na dogon lokaci ya kasu kashi 105 ℃, 125 ℃, 150 ℃ fayiloli guda uku, ana iya yin shukar samarwa bisa ga buƙatun daban-daban na masu amfani ko ƙa'idodi, halogen-free ko halogen-dauke da shingen mai.
Sanannen abu ne cewa polyolefins ba polar polar ba ne ko masu rauni. Kamar yadda suke kama da man ma'adinai a cikin polarity, polyolefins yawanci ana la'akari da su ba su da juriya ga man fetur bisa ga ka'idar dacewa irin wannan. Koyaya, yawancin ma'auni na kebul a gida da waje kuma sun nuna cewa juriya mai alaƙa dole ne su kasance da juriya mai kyau ga mai, kaushi har ma da slurries mai, acid da alkalis. Wannan ƙalubale ne ga masu bincike na kayan aiki, yanzu, ko a China ko a ƙasashen waje, an haɓaka waɗannan kayan da ake buƙata, kuma tushen kayan sa shine EVA.
3. 3 Oxygen shinge abu
Filayen igiyoyi masu maƙalli da yawa suna da ɓangarorin da yawa tsakanin muryoyin da ake buƙatar cikewa don tabbatar da bayyanar kebul mai zagaye, idan an yi abin da ke cikin kube na waje da shingen man fetur mara halogen. Wannan nau'in cikawa yana aiki azaman shinge na harshen wuta (oxygen) lokacin da kebul ɗin ke ƙonewa kuma ana kiransa da "shigin oxygen" a cikin masana'antar.
Abubuwan buƙatu na asali don kayan shinge na iskar oxygen sune: kyawawan kaddarorin extrusion, kyakkyawan jinkirin harshen wuta mara halogen (ƙididdiga oxygen yawanci sama da 40) da ƙarancin farashi.
An yi amfani da wannan shingen iskar oxygen da yawa a cikin masana'antar kebul fiye da shekaru goma kuma ya haifar da ci gaba mai mahimmanci a cikin jinkirin wutar lantarki. Ana iya amfani da shingen iskar oxygen ga igiyoyi masu hana harshen wuta marasa halogen da igiyoyi masu hana harshen wuta marasa halogen (misali PVC). Yawancin ayyuka sun nuna cewa igiyoyi masu shingen iskar oxygen sun fi dacewa su wuce gwaje-gwajen ƙonawa a tsaye da haɗakarwa.
Daga ra'ayi na kayan aiki na kayan aiki, wannan kayan shinge na oxygen shine ainihin "mafi girma mai girma", saboda don saduwa da ƙananan farashi, wajibi ne a yi amfani da babban filler, don cimma babban ma'aunin iskar oxygen kuma dole ne ya ƙara yawan adadin. (2 zuwa 3 sau) na Mg (OH) 2 ko Al (OH) 3, kuma don fitar da kyau kuma dole ne ya zaɓi EVA azaman kayan tushe.
3. 4 Gyara kayan sheathing PE
Abubuwan sheathing na polyethylene suna fuskantar matsaloli guda biyu: na farko, suna da saurin narke karyewa (watau sharkskin) yayin extrusion; abu na biyu, suna da saurin fashe danniya na muhalli. Mafi sauƙaƙan bayani shine ƙara wani yanki na EVA a cikin tsari. ana amfani da shi azaman EVA da aka gyara galibi ta amfani da ƙarancin abun ciki na VA, ma'aunin narkewar sa zuwa tsakanin 1 zuwa 2 ya dace.
4. Abubuwan cigaba
(1) An yi amfani da EVA sosai a cikin masana'antar kebul, adadin shekara-shekara a cikin ci gaba a hankali da ci gaba. Musamman a cikin shekaru goma da suka gabata, saboda mahimmancin kariyar muhalli, juriya na tushen EVA ya kasance mai saurin ci gaba, kuma ya maye gurbin wani sashi na kayan aikin USB na tushen PVC. Kyakkyawan aikin farashi da kyakkyawan aiki na tsarin extrusion yana da wuyar maye gurbin kowane kayan.
(2) na USB masana'antu na shekara-shekara amfani da EVA guduro kusa da 100,000 ton, zaɓi na Eva guduro iri, VA abun ciki daga low zuwa high za a yi amfani da, guda biyu tare da na USB abu granulation sha'anin girman ba babba, yada a kowace sha'anin kowace shekara. kawai a cikin dubban ton na Eva guduro sama da ƙasa, kuma ta haka ne ba zai zama EVA masana'antu giant sha'anin hankali. Misali, mafi girman adadin tushen tushen harshen wuta mara halogen, babban zaɓi na VA / MI = 28/2 ~ 3 na EVA resin (kamar US DuPont's EVA 265 #). Kuma wannan ƙayyadaddun darajar EVA ya zuwa yanzu babu masana'antun cikin gida don samarwa da samarwa. Ba a ma maganar VA abun ciki sama da 28, da narke index kasa da 3 na sauran EVA guduro samarwa da wadata.
(3) Kamfanoni na kasashen waje da ke samar da EVA saboda babu masu fafatawa a cikin gida, kuma farashin ya dade yana da yawa, yana hana sha'awar samar da kebul na cikin gida. fiye da 50% na VA abun ciki na roba-nau'in EVM, a kasashen waje kamfanin mamaye, kuma farashin ne kama da VA abun ciki na iri 2 zuwa 3 sau. Irin wannan farashi mai girma, bi da bi, yana shafar adadin wannan nau'in roba na EVM, don haka masana'antar kebul na kira ga masana'antun EVA na cikin gida, don haɓaka ƙimar samar da gida na EVA. Ƙarin samar da masana'antu ya kasance mai yawa amfani da EVA guduro.
(4) Dogaro da guguwar kariyar muhalli a zamanin duniyar duniya, masana'antar kebul tana ɗaukar EVA a matsayin mafi kyawun kayan tushe don juriya ga yanayin muhalli. Yin amfani da EVA yana girma a cikin adadin 15% a kowace shekara kuma hangen nesa yana da ban sha'awa sosai. Adadi da haɓakar haɓakar kayan kariya da matsakaici da matsakaicin ƙarfin wutar lantarki na kebul na samarwa da ƙimar girma, kusan 8% zuwa 10% tsakanin; Ƙwayoyin polyolefin suna girma da sauri, a cikin 'yan shekarun nan sun kasance a 15% zuwa 20% tsakanin, kuma a cikin shekaru 5 zuwa 10 na gaba na gaba, na iya kula da wannan girman girma.
Lokacin aikawa: Yuli-31-2022