I. Ukubaluleka Kokulinganiswa Kokujiya Kwenjoloba Ekukhiqizweni Kwe-SBR
Ukukhiqizwa okuphumelelayo kwe-Styrene Butadiene Rubber (SBR) kuncike ekulawulweni okunembile kanye nokuqapha izakhiwo zayo ze-rheological. Ukuqina, okulinganisa ukumelana kwezinto ekugelezeni, kumi njengepharamitha eyodwa ebaluleke kakhulu ye-physicochemical elawula kokubili ukucutshungulwa kwamakhemikhali enjoloba aphakathi kanye nenkomba yokugcina yekhwalithi yezimpahla eziqediwe.
Ku-irabha yokwenziwainqubo yokukhiqiza, i-viscosity inikeza i-proxy eqondile nelinganisekayo yezici zesakhiwo eziyisisekelo ze-polymer, ikakhulukazi isisindo sayo sama-molecule (MW) kanye nokusatshalaliswa kwesisindo sama-molecule (MWD).ukulinganiswa kwe-viscosity yerabhakuphazamisa ngqo ukuphathwa kwezinto kanye nokusebenza komkhiqizo oqediwe. Isibonelo, ama-compounds abonisa i-viscosity ephezulu kakhulu abeka imikhawulo enzima emisebenzini engezansi njengokukhipha noma ukucubungula, okuholela ekusetshenzisweni kwamandla okuphezulu, ukwanda kokucindezeleka kokusebenza, kanye nokwehluleka kwemishini okungenzeka. Ngakolunye uhlangothi, ama-compounds ane-viscosity ephansi kakhulu angase angabi namandla okuncibilika adingekayo ukuze alondoloze ubuqotho obukhulu ngesikhathi sokwakheka noma isigaba sokugcina sokuqina.
Irabha ye-Styrene-Butadiene (SBR)
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Ngaphandle kokuphathwa kwemishini nje, ukulawulwa kwe-viscosity kubalulekile ukuze kufezwe ukusabalala okufanayo kwezithasiselo eziqinisayo ezibalulekile, njenge-carbon black kanye ne-silica. Ukufana kwalokhu kusabalala kunquma izakhiwo zokugcina zemishini, kufaka phakathi izibalo ezibalulekile njengamandla okudonswa, ukumelana nokuklwebheka, kanye nokuziphatha okuyinkimbinkimbi okubonakalayo ngemva kokusetshenziswa kwe-inqubo yokwenziwa kwerabha ibe yi-vulcanization.
II. Izisekelo ze-Styrene Butadiene Rubber (SBR)
Iyini i-Styrene Butadiene Rubber?
Irabha ye-Styrene Butadiene (SBR) iyi-elastomer yokwenziwa ehlukahlukene, esetshenziswa kabanzi ngenxa yesilinganiso sayo esihle kakhulu sezindleko-nokusebenza kanye nokutholakala kwevolumu ephezulu. I-SBR yenziwe njenge-copolymer etholakala kakhulu kuma-monomer angu-1,3-butadiene (cishe angu-75%) kanye nama-monomer e-styrene (cishe angu-25%). Lawa ma-monomer ahlanganiswa ngokusabela kwamakhemikhali okubizwa ngokuthi i-copolymerization, akha amaketanga amade, e-multi-unit polymer. I-SBR yenzelwe ngqo izinhlelo zokusebenza ezifuna ukuqina okuphezulu kanye nokumelana nokuguguleka okumangalisayo, okwenza kube ukukhetha okuhle kakhulu kwama-treads amathayi.
Inqubo Yokukhiqiza Injoloba Yokwenziwa
Ukwenziwa kwe-SBR kufezwa ngezindlela ezimbili ezihlukene ze-polymerization zezimboni, okuholela ezintweni ezinezici ezihlukile ezingokwemvelo futhi ezidinga ukulawulwa kwe-viscosity ethile ngesikhathi sesigaba soketshezi.
I-Emulsion Polymerization (E-SBR):Kule ndlela yakudala, ama-monomer ahlakazeka noma axutshwe nge-emuls kusisombululo samanzi kusetshenziswa i-surfactant efana nensipho. Ukusabela kuqala ngabaqalisi be-free radical futhi kudinga iziqinisi ukuvimbela ukuwohloka komkhiqizo. I-E-SBR ingakhiqizwa kusetshenziswa amazinga okushisa enqubo ashisayo noma abandayo; i-E-SBR ebandayo, ikakhulukazi, yaziwa ngokumelana nokuguguleka okuphezulu, amandla okuthamba, kanye nokuqina okuphansi.
Isixazululo se-Polymerization (S-SBR):Le ndlela ethuthukisiwe ihilela i-anionic polymerization, ngokuvamile isebenzisa i-alkyl lithium initiator (njenge-butyllithium) ngaphakathi kwe-hydrocarbon solvent, ngokuvamile i-hexane noma i-cyclohexane. Amabanga e-S-SBR ngokuvamile anesisindo esiphezulu sama-molecule kanye nokusatshalaliswa okuncane, okuholela ezicini ezithuthukisiwe ezifana nokuguquguquka okungcono, amandla aphezulu okudonsa, kanye nokumelana okuphansi kakhulu kokugoqa emathayini, okwenza i-S-SBR ibe umkhiqizo ophambili nobiza kakhulu.
Okubaluleke kakhulu, kuzo zombili izinqubo, ukusabela kwe-polymerization kumele kuqedwe ngokunembile ngokungenisa i-chain terminator noma i-short-stop agent emanzini angcolile e-reactor. Lokhu kulawula ubude be-chain yokugcina, isinyathelo esisungula ngqo isisindo sokuqala sama-molecule, futhi ngenxa yalokho, isisekelo.ukujiya kwerabhangaphambi kokuhlanganisa.
Izakhiwo Zerabha Ye-Styrene Butadiene
I-SBR ilinganiswa ngephrofayili eqinile yezakhiwo zomzimba nezemishini:
Ukusebenza Kwemishini:Amandla abalulekile afaka phakathi amandla aphezulu okudonseka, ngokuvamile asukela ku-500 kuya ku-3,000 PSI, kanye nokumelana okuhle kakhulu kokuhuzuka. I-SBR iphinde ibonise ukumelana okuhle nesethi yokucindezelwa kanye nokumelana okuphezulu komthelela. Ngaphezu kwalokho, izinto zokwakha azikwazi ukuqhekeka ngokwemvelo, okuyisici esibalulekile esivumela ukufakwa kwenani elikhulu lama-filler okuqinisa, njengomnyama we-carbon, ukuze kuthuthukiswe amandla kanye nokumelana ne-UV.
Iphrofayili Yamakhemikhali Nokushisa:Nakuba ngokuvamile imelana namanzi, utshwala, ama-ketone, kanye nama-asidi athile e-organic, i-SBR ibonisa ubuthakathaka obuphawulekayo. Ayimelani kahle namafutha asekelwe ku-petroleum, amafutha e-hydrocarbon anuka kamnandi, i-ozone, kanye nezinyibilikisi ze-halogenated. Ngokwesimo sezulu, i-SBR igcina ukuguquguquka kuzo zonke izinhlobo eziningi, ngokusetshenziswa okuqhubekayo okuphezulu okungaba ngu-225°F kanye nokuguquguquka okuphansi kokushisa okufika ku--60℉.
Ukuqina njengesibonakaliso esiyinhloko sesisindo sama-molecular kanye nesakhiwo se-chain
Izici ze-rheological ze-polymer eluhlaza zinqunywa ngokuyisisekelo yisakhiwo sama-molecule—ubude kanye nezinga lokuhlanganiswa kwamaketanga e-polymer—okusungulwe ngesikhathi sesigaba se-polymerization. Isisindo sama-molecule esiphezulu ngokuvamile sisho i-viscosity ephezulu kanye namazinga okugeleza okuncibilika aphansi ngokufanayo (i-MFR/MVR). Ngakho-ke, ukulinganisa i-viscosity yangaphakathi (IV) ngokushesha ekukhishweni kwe-reactor kufana nokusebenza ngokuqhubekayo nokuqapha ukwakheka kwesakhiwo sama-molecule esihlosiwe.
III. Izimiso Zokusebenza Kwemithambo Yezinzwa Ezilawula Ukucutshungulwa Kwe-SBR
Izimiso ze-rheological, ukuncika kwesilinganiso sokusika, ukuzwela izinga lokushisa/ingcindezi.
I-Rheology, isifundo sokuthi izinto ziguquka futhi zigeleza kanjani, inikeza uhlaka lwesayensi lokuqonda ukuziphatha kwe-SBR ngaphansi kwezimo zokucubungula zezimboni. I-SBR ichazwa njengento eyinkimbinkimbi ye-viscoelastic, okusho ukuthi ikhombisa izakhiwo ezixuba izimpendulo eziqinile (ezihlala njalo, ezifana noketshezi) kanye nezimpendulo ezinwebekayo (ezilulamayo, ezifana nokuqina). Ukubusa kwalezi zici kuncike kakhulu esilinganisweni kanye nobude bomthwalo osetshenzisiwe.
Ama-compound e-SBR empeleni ayizinhlayiya ezingezona eze-Newtonian. Lokhu kusho ukuthi zibonakala kahle.i-viscosity yerabhaakuyona inani elihlala njalo kodwa libonisa ukubaluleka okubalulekileukuncika kwesilinganiso sokucheba; i-viscosity iyancipha kakhulu njengoba izinga lokugunda landisa into eyaziwa ngokuthi i-shear thinning. Lokhu kuziphatha okungeyona i-Newtonian kunemiphumela ejulile ekulawulweni kwekhwalithi. Amanani e-viscosity atholakala ngamanani aphansi okugunda, njengalawo alinganiswa ekuhlolweni kwe-viscometer yendabuko ye-Mooney, anganikeza ukumelwa okunganele kokuziphatha kwezinto ngaphansi kwamazinga aphezulu okugunda atholakala ekusebenzeni kokuxuba, ukuxova, noma ukukhipha. Ngale kokugunda, i-viscosity nayo ibucayi kakhulu ekushiseni; ukushisa kwenqubo kunciphisa i-viscosity, okusiza ukugeleza. Ngenkathi ingcindezi nayo ithinta i-viscosity, ukugcina izinga lokushisa elizinzile kanye nomlando wokugunda ohambisanayo kubaluleke kakhulu, njengoba i-viscosity ingahluka ngokuguquguqukayo ngokugunda, ingcindezi, kanye nesikhathi sokucubungula.
Umthelela Wezinto Zokwenza Amapulasitiki, Izinto Zokugcwalisa, kanye Nezinsiza Zokucubungula Ekuqineni Kwe-SBR
Iukucutshungulwa kwerabhaisigaba, esaziwa ngokuthi ukuhlanganisa, sihilela ukuhlanganisa izithasiselo eziningi ezishintsha kakhulu i-rheology ye-SBR polymer eyisisekelo:
Izinto zokwenziwa ngepulasitiki:Amafutha enqubo abalulekile ekuthuthukiseni ukuguquguquka kanye nokucutshungulwa okuphelele kwe-SBR. Asebenza ngokunciphisa i-composite viscosity ye-compound, okusiza ngesikhathi esifanayo ukusabalala okufanayo kwama-fillers futhi kuthambise i-polymer matrix.
Izigcwalisi:Izinto eziqinisayo, ikakhulukazi i-carbon black kanye ne-silica, zandisa kakhulu i-viscosity yezinto ezibonakalayo, okuholela ezimweni eziyinkimbinkimbi zomzimba eziqhutshwa ukusebenzisana kwe-filler-filler kanye ne-filler-polymer. Ukufinyelela ukuhlakazeka okuhle kuyibhalansi; izinto ezifana ne-glycerol zingasetshenziswa ukuthambisa izitshali ze-lignosulfonate, ukulungisa i-viscosity yokugcwalisa eduze kwe-SBR matrix viscosity, ngaleyo ndlela kuncishiswe ukwakheka kwe-agglomerate futhi kuthuthukiswe i-homogeneity.
Ama-Vulcanizing Ejenti:La makhemikhali, okuhlanganisa nesibabule kanye nama-accelerator, aletha izinguquko ezibalulekile ku-rheology yenhlanganisela engakaqedwa. Athinta izici ezifana nokuphepha kokushiswa (ukumelana nokuxhumanisa ngaphambi kwesikhathi). Ezinye izithasiselo ezikhethekile, njenge-silica efumile, zingasetshenziswa ngendlela efanele njengezinto ezikhulisa i-viscosity ukuze kufezwe imigomo ethile ye-rheological, njengokukhiqiza amafilimu ajiyile ngaphandle kokushintsha okuqukethwe okuphelele kwezinto eziqinile.
Ukuxhumanisa i-Rheology ne-Vulcanization yenqubo yerabha kanye ne-Final Cross-Link Density
Ukulungiswa kwe-rheological okunikezwa ngesikhathi sokuhlanganiswa nokwakheka kuhlobene ngqo nokusebenza kokugcina kwenkonzo yomkhiqizo ovutshiwe.
Ukufana Nokuhlakazeka:Amaphrofayili e-viscosity angaguquki ngesikhathi sokuxuba—ngokuvamile ahlotshaniswa nokufakwa kwamandla okungenawo amandla afanele—kubangela ukuhlakazeka okubi kanye nokusatshalaliswa okungalingani kwephakeji yokuxhumanisa (isibabule kanye nama-accelerator).
Inqubo Yokuvungulwa Kwerabha:Le nqubo yamakhemikhali engenakuguqulwa ihilela ukushisa i-SBR compound, ngokuvamile nge-sulfur, ukudala izixhumanisi ezihlala njalo phakathi kwamaketanga e-polymer, okuthuthukisa kakhulu amandla erabha, ukuguquguquka kwayo, kanye nokuqina kwayo. Le nqubo ihilela izigaba ezintathu: isigaba sokungeniswa (sokushisa) lapho kwenzeka khona ukwakheka kokuqala; isigaba sokuxhumanisa noma sokulungisa (ukusabela okusheshayo ku-250 ℉ kuya ku-400 ℉; kanye nesimo esihle kakhulu.
Ubuningi be-Cross-Link:Izakhiwo zokugcina zemishini zilawulwa ukuminyana kwe-cross-link okufinyelelwe. I-D ephezulucAmanani avimbela ukunyakaza kwe-molecule chain, aphakamise i-modulus yokugcina futhi athonye impendulo ye-viscoelastic engaqondile yento (eyaziwa ngokuthi umphumela we-Payne). Ngakho-ke, ukulawulwa okunembile kwe-rheological ezigabeni zokucubungula ezingakaphulukiswa kubalulekile ukuqinisekisa ukuthi izandulela zama-molecule zilungiselelwe kahle ukusabela okulandelayo kokwelapha.
IV. Izinkinga Ezikhona Ekulinganisweni Kokugoba
Imikhawulo Yokuhlolwa Okungaxhunyiwe Ku-inthanethi Kwendabuko
Ukuthembela kabanzi ezindleleni zokulawula ikhwalithi ezivamile, ezingaqhubeki, nezidinga abasebenzi abaningi kubeka imingcele ebalulekile yokusebenza ekukhiqizweni okuqhubekayo kwe-SBR, okuvimbela ukuthuthukiswa kwenqubo okusheshayo.
Ukubikezela kanye nokuLag kwe-Mooney Viscosity:Inkomba yekhwalithi eyinhloko, i-Mooney viscosity, ilinganiswa ngokujwayelekile ngaphandle kwe-inthanethi. Ngenxa yobunzima obubonakalayo kanye ne-viscosity ephezulu yezimboniinqubo yokukhiqiza irabha, ayikwazi ukulinganiswa ngqo ngesikhathi sangempela ngaphakathi kwe-internal mixer. Ngaphezu kwalokho, ukubikezela ngokunembile leli nani kusetshenziswa amamodeli endabuko okuhlola kuyinselele, ikakhulukazi kuma-compounds afaka ama-filler. Isikhathi esibekiwe esihambisana nokuhlolwa kwelabhorethri sibambezela izenzo zokulungisa, okwandisa ingozi yezezimali yokukhiqiza inani elikhulu lezinto ezingacacisiwe.
Umlando Wemishini Oshintshiwe:I-capillary rheometry, yize ikwazi ukuchaza ukuziphatha kokugeleza, idinga ukulungiswa okubanzi kwesampula. Izinto kumele zenziwe kabusha zibe yizilinganiso ezithile zesilinda ngaphambi kokuhlolwa, inqubo eguqula umlando womshini wenhlanganisela. Ngenxa yalokho, i-viscosity elinganisiwe ingase ingabonisi ngokunembile isimo sangempela senhlanganisela ngesikhathi sezimboni.ukucutshungulwa kwerabha.
Idatha Yephuzu Elilodwa Enganele:Izinga lokugeleza lokuncibilika elijwayelekile (i-MFR) noma izinga lomthamo wokuncibilika (i-MVR) liveza inkomba yokugeleza eyodwa kuphela ezimweni ezihleliwe. Lokhu akwanele kwi-SBR engeyona i-Newtonian. Amaqoqo amabili ahlukene angabonisa amanani afanayo e-MVR kodwa abe nokuqina okuhluke kakhulu emazingeni aphezulu okushefa ahlobene nokukhishwa. Lokhu kungafani kungabangela ukwehluleka kokucubungula okungabikezelwa.
Izindleko kanye Nomthwalo Wezokuthutha:Ukuthembela ekuhlaziyweni kwelabhorethri okungaphandle kwendawo kuletha izindleko ezinkulu zezokuthutha kanye nokubambezeleka kwesikhathi. Ukuqapha okuqhubekayo kunikeza inzuzo yezomnotho ngokunciphisa kakhulu inani lamasampula adinga ukuhlaziywa kwangaphandle.
Inselele Yokulinganisa Ama-SBR Compounds Ane-Viscosity Ephakeme kanye Nezigaba Eziningi
Ukuphathwa kwezakhi zerabha zezimboni kuhilela izinto ezibonisa ukuqina okuphezulu kakhulu kanye nokuziphatha okuyinkimbinkimbi kwe-viscoelastic, okudala izinselele eziyingqayizivele zokulinganisa okuqondile.
Ukushelela Nokuphuka:Izinto zerabha eziqinile nezinobukhulu obuphezulu zivame ukuba nezinkinga ezifana nokushelela kodonga kanye nokuqhekeka kwesampula okubangelwa ukunwebeka uma kuhlolwa kuma-rheometer endabuko avulekile. Imishini ekhethekile, njenge-rheometer eguquguqukayo enomklamo womngcele ovaliwe, ohlanganisiwe, iyadingeka ukuze kunqotshwe le miphumela, ikakhulukazi ezintweni ezigcwalisiwe lapho kwenzeka khona ukusebenzisana okuyinkimbinkimbi kwe-polymer-filler.
Ukugcinwa Nokuhlanza:Izinhlelo ezijwayelekile zokugeleza kwegazi eziku-inthanethi noma ze-capillary zivame ukuvaleka ngenxa yemvelo yokunamathela, enokuqina okuphezulu kwama-polymers nama-fillers. Lokhu kudinga izindlela zokuhlanza eziyinkimbinkimbi futhi kuholela esikhathini esibi kakhulu sokungasebenzi, okuyisimo esibi kakhulu ezindaweni zokukhiqiza eziqhubekayo.
Isidingo sethuluzi eliqinile le-viscosity yangaphakathi yezixazululo ze-polymer.
Esigabeni sokuqala sesisombululo noma se-slurry, ngemuva kwe-polymerization, ukulinganisa okubalulekile yi-intrinsic viscosity (IV), ehlobene ngqo nesisindo sama-molecule kanye nokusebenza kwe-polymer. Izindlela zelebhu zendabuko (isb., i-GPC noma ama-capillary engilazi) zihamba kancane kakhulu ekulawulweni kwesikhathi sangempela.
Indawo yezimboni idinga ukwenziwa okuzenzakalelayo nokuqinileithuluzi le-viscosity yangaphakathiIzixazululo zesimanje, njenge-IVA Versa, zenza yonke inqubo isebenze ngokuzenzakalela kusetshenziswa i-viscometer ehlobene ne-dual-capillary ukukala i-viscosity yesisombululo, kunciphisa ukuxhumana komsebenzisi nezinyibilikisi futhi kufezwe ukunemba okuphezulu (amanani e-RSD angaphansi kuka-1%). Ekusetshenzisweni okuqondile esigabeni sokuncibilika, i-Side Stream Online-Rheometers (SSR) inganquma inani le-IV-Rheo ngokusekelwe ekulinganisweni kwe-viscosity okuqhubekayo kwe-shear ngesilinganiso se-shear esingaguquki. Lokhu kulinganisa kusungula ubudlelwano obuhambisana nokuhlolwa obuvumela ukuqapha izinguquko ze-MW emsakazweni wokuncibilika.
V. Izigaba Zenqubo Ezibalulekile Zokuqapha Ukugoba
Ukubaluleka kokulinganiswa kwe-inthanethi ekukhishweni kwe-polymerization reactor, ukuxuba/ukuxova, kanye nokwakheka kwangaphambi kokukhipha.
Ukusebenzisa ukulinganisa i-viscosity ku-inthanethi kubalulekile ngoba izigaba ezintathu zenqubo eyinhloko—i-polymerization, i-compound (mixing), kanye ne-final form (extrusion)—ngasinye sisungula izici ezithile ze-rheological, ezingenakuguqulwa. Ukulawula kulezi zindawo kuvimbela amaphutha ekhwalithi ukuthi adluliselwe phansi komfula.
Ukukhishwa kwe-polymerization Reactor: Ukuqapha ukuguqulwa, isisindo sama-molecule.
Inhloso eyinhloko kulesi sigaba ukulawula ngokunembile izinga lokusabela okusheshayo kanye nokusatshalaliswa kwesisindo sokugcina sama-molecule (MW) se-SBR polymer.
Ulwazi ngesisindo sama-molecule esishintshayo lubalulekile, njengoba lunquma izakhiwo zokugcina zomzimba; noma kunjalo, amasu endabuko avame ukukala i-MW kuphela lapho kuqedwa ukusabela. Ukuqapha ngesikhathi sangempela kwe-slurry noma i-solution viscosity (cishe i-intrinsic viscosity) kulandelela ngqo ubude beketanga kanye nokwakheka kwezakhiwo.
Ngokusebenzisa impendulo ye-viscosity yesikhathi sangempela, abakhiqizi bangafaka ukulawula okunamandla nokusebenzayo. Lokhu kuvumela ukulungiswa okunembile kokugeleza komlawuli wesisindo sama-molecule noma i-agent ye-short-stopngaphambiukuguqulwa kwe-monomer kufinyelela esiphezulu sako. Leli khono liphakamisa ukulawulwa kwenqubo kusukela ekuhlolweni kwekhwalithi yokusabela (okubandakanya ukuklebhula noma ukuhlanganisa kabusha ama-batches angekho ku-specification) kuya ekulawulweni okuqhubekayo, okuzenzakalelayo kwesakhiwo sesisekelo se-polymer. Isibonelo, ukuqapha okuqhubekayo kuqinisekisa ukuthi i-polymer eluhlaza i-Mooney viscosity ihlangabezana nezilinganiso lapho izinga lokuguqulwa lifinyelela ku-70%. Ukusetshenziswa kwama-probe e-torsional resonator aqinile, angaphakathi, aklanyelwe ukumelana namazinga okushisa aphezulu kanye nezingcindezi ezibonakala emfucumfuceni ye-reactor, kubalulekile lapha.
Ukuxuba/Ukuxova: Ukuthuthukisa ukuhlakazeka okungeziwe, ukulawula ukucheba, ukusetshenziswa kwamandla.
Umgomo wesigaba sokuxuba, esivame ukwenziwa ku-mixer yangaphakathi, ukufeza ukusabalala okufanayo, okufanayo kwe-polymer, ukuqinisa ama-filler, kanye nezinsiza zokucubungula ngenkathi kulawulwa ngokucophelela umlando wokushisa nowokucheba wenhlanganisela.
Iphrofayili ye-viscosity isebenza njengesibonakaliso esiqondile sekhwalithi yokuxuba. Amandla aphezulu okusika akhiqizwa yi-rotors aphula irabha futhi afeze ukuhlakazeka. Ngokuqapha ushintsho lwe-viscosity (okuvame ukucatshangwa kusukela ku-torque yesikhathi sangempela kanye nokufakwa kwamandla), okuqondileindawo yokugcinaUmjikelezo wokuxuba unganqunywa ngokunembile. Le ndlela ingcono kakhulu kunokuthembela ezikhathini zomjikelezo wokuxuba ezingaguquki, ezingaba phakathi kwemizuzu eyi-15 kuya kwengama-40 futhi zivame ukuhlukahluka komqhubi kanye nezici zangaphandle.
Ukulawula i-compound viscosity ngaphakathi kobubanzi obubekiwe kubalulekile ngekhwalithi yezinto ezibonakalayo. Ukulawulwa okunganele kuholela ekuhlakazekeni okubi kanye nokukhubazeka kwezakhiwo zezinto zokugcina. Kurabha ene-viscosity ephezulu, isivinini sokuxuba esanele sibalulekile ukuze kufezwe ukuhlakazeka okudingekayo. Njengoba kunobunzima bokufaka inzwa ebonakalayo endaweni eguquguqukayo, ene-viscosity ephezulu ye-mixer yangaphakathi, ukulawula okuthuthukisiwe kuncike kuizinzwa ezithambileLawa mamodeli aqhutshwa idatha asebenzisa iziguquguquko zenqubo (isivinini se-rotor, izinga lokushisa, ukudonsa kwamandla) ukubikezela ikhwalithi yokugcina yeqembu, njengokuthambekela kwalo kweMooney, ngaleyo ndlela enikeza isilinganiso sesikhathi sangempela senkomba yekhwalithi.
Ikhono lokunquma indawo yokugcina yokuxuba efanele ngokusekelwe kuphrofayili ye-viscosity yesikhathi sangempela liholela ekuzuzeni okukhulu kwamandla kanye nokusetshenziswa kwamandla. Uma i-batch ifinyelela i-viscosity yayo yokuhlakazeka okuqondiwe ngokushesha kunesikhathi somjikelezo esinqunyiwe esinqunyiwe, ukuqhubeka nenqubo yokuxuba kuchitha amandla futhi kuyingozi yokulimaza amaketanga e-polymer ngokuxuba ngokweqile. Ukwenza ngcono inqubo ngokusekelwe kuphrofayili ye-viscosity kunganciphisa izikhathi zomjikelezo ngo-15-28%, okuhunyushwa ngqo ekusebenzeni kahle kanye nokuzuza kwezindleko.
Ngaphambi Kokukhipha/Ukwakheka: Ukuqinisekisa ukugeleza kokuncibilika okuqhubekayo, ukuzinza kobukhulu.
Lesi sigaba sihilela ukufaka ipulasitiki ku-strip yerabha eqinile bese uyiphoqa ukuthi idlule kudayi ukuze yakhe iphrofayili eqhubekayo, ngokuvamile edinga ukuhluzwa okuhlanganisiwe.
Ukulawulwa kwe-viscosity lapha kubaluleke kakhulu ngoba kulawula ngqo amandla okuncibilika kwe-polymer kanye nokugeleza kwayo. Ukugeleza okuncibilikayo okuphansi (i-viscosity ephezulu) ngokuvamile kuyathandwa ekukhipheni, njengoba kunikeza amandla aphezulu okuncibilika, okubalulekile ekuphatheni ukulawulwa kwesimo (ukuzinza kobukhulu) bephrofayili kanye nokunciphisa ukuvuvukala kwe-die. Ukugeleza kokuncibilika okungaguquki (i-MFR/MVR) kuholela ezifweni zekhwalithi yokukhiqiza: ukugeleza okuphezulu kungabangela ukukhanya, kanti ukugeleza okuphansi kungaholela ekugcwalisweni kwezingxenye okungaphelele noma ukumbozwa.
Ubunzima bokulawulwa kwe-viscosity ekukhishweni, okusengozini enkulu yokuphazamiseka kwangaphandle kanye nokuziphatha kwe-rheological okungekho emgqeni, kudinga izinhlelo zokulawula ezithuthukisiwe. Amasu afana ne-Active Disturbance Rejection Control (ADRC) asetshenziswa ukuphatha ngokuqhubekayo ukushintshashintsha kwe-viscosity, kufezwe ukusebenza okungcono ekugcineni i-viscosity ebonakalayo ehlosiwe uma kuqhathaniswa nabalawuli be-Proportional-Integral (PI) abavamile.
Ukuvumelana kwe-melt viscosity ekhanda le-die kuyisici sokugcina sekhwalithi yomkhiqizo kanye nokwamukelwa kwe-geometric. I-Extrusion ikhulisa imiphumela ye-viscoelastic, futhi ukuzinza kobukhulu kuzwela kakhulu ekushintsheni kwe-melt viscosity, ikakhulukazi ngamanani aphezulu okusika. Ukulinganiswa kwe-melt viscosity ku-inthanethi ngaphambi nje kwe-die kuvumela ukulungiswa okusheshayo, okuzenzakalelayo kwamapharamitha enqubo (isb., isivinini sesikulufu noma iphrofayili yokushisa) ukuze kugcinwe i-viscosity ebonakalayo ehambisanayo, kuqinisekiswe ukunemba kwe-geometric kanye nokunciphisa i-scrap.
Ithebula II libonisa izidingo zokuqapha kulo lonke uchungechunge lokukhiqiza lwe-SBR.
Ithebula II. Izidingo Zokuqapha Ukugoba Kuzo Zonke Izigaba Zokucubungula ze-SBR
| Isigaba Senqubo | Isigaba Sokunamathela | Ipharamitha Eqondiwe | Ubuchwepheshe Bokulinganisa | Isenzo Sokulawula Sinikwe Amandla |
| Ukukhishwa Kwe-Reactor | Isixazululo/Udaka | Ukuqina Kwangaphakathi(Isisindo sama-molecule) | I-Rheometer Yokusakaza Eceleni (SSR) noma i-Automated IV | Lungisa i-ejenti yokuma okufushane noma izinga lokugeleza komlawuli. |
| Ukuxuba/Ukuxova | Inhlanganisela Enamandla Okugqama | Ukubonakala Kokugqama KweMooney (Ukubikezela Okubonakalayo Kwe-Torque) | Inzwa Ethambile (Ukumodela Kokufaka I-Torque/Amandla) | Lungiselela isikhathi somjikelezo wokuxuba kanye nesivinini se-rotor ngokusekelwe ekuqineni kwe-end-point. |
| Ngaphambi Kokukhipha/Ukwakheka | Ukuncibilika kwe-Polymer | Ukuqina Okuncibilikayo Okubonakalayo (ukuxhumana kwe-MFR/MVR) | I-Inline Torsional Resonator noma i-Capillary Viscometer | Lungisa isivinini/izinga lokushisa lesikulufu ukuqinisekisa ukuzinza kobukhulu kanye nokuvuvukala kwe-die okuqhubekayo. |
Funda Ngamamitha Obuningi Engeziwe
Amamitha Ezinqubo Engeziwe Ku-inthanethi
VI. Ubuchwepheshe Bokulinganisa Ukuthamba Ku-inthanethi
Imitha Yokugoba Okumanzi yeLonnmeter Emugqeni
Ukuze kunqotshwe imikhawulo engokwemvelo yokuhlolwa kwelabhorethri, izinqubo zesimanjeukucutshungulwa kwerabhakudinga izinsimbi eziqinile nezithembekile. Ubuchwepheshe be-torsional resonator bumelela intuthuko enkulu ekuzweleni okuqhubekayo, okuqondile kwe-rheological, okukwazi ukusebenza endaweni enzima yokukhiqizwa kwe-SBR.
Amadivayisi afana ne-Imitha Yokugoba Okumanzi yeLonnmeter Emugqenisebenzisa i-torsional resonator (into edlidlizayo) ecwiliswe ngokuphelele kuketshezi lwenqubo. Idivayisi ilinganisa i-viscosity ngokulinganisa i-mechanical damping etholwa yi-resonator ngenxa yoketshezi. Lokhu kulinganiswa kwe-damping bese kucutshungulwa, ngokuvamile kanye nokufundwa kobuningi, ngama-algorithms akhethekile ukuze kunikezwe imiphumela ye-viscosity enembile, ephindaphindwayo, nezinzile.
Lobu buchwepheshe bufanelekela ngokukhethekile izinhlelo zokusebenza ze-SBR ngenxa yamakhono abo okusebenza anzima:
Ukuqina Nokungavikeleki Emzimbeni:Izinzwa zivame ukuba nokwakhiwa kwensimbi yonke (isb., Insimbi Engagqwali engu-316L) kanye nezivalo zensimbi ezivalwe ngensimbi, okususa isidingo sama-elastomer angase avuvuke noma ahluleke uma kushiswa ukushisa okuphezulu kanye nokuvezwa ngamakhemikhali.
Ububanzi Obubanzi kanye Nokuhambisana Koketshezi:Lezi zinhlelo zingaqaphaukujiya kwerabhaamakhemikhali ahlukene kakhulu, kusukela kumanani aphansi kakhulu kuya kwaphezulu kakhulu (isb., 1 kuya ku-1,000,000+ cP). Asebenza kahle ngokulinganayo ekuqapheni uketshezi olungewona u-Newtonian, olulodwa, kanye nolwe-multi-phase, olubalulekile kuma-slurries e-SBR kanye nokuncibilika kwe-polymer okugcwele.
Izimo Zokusebenza Ezinzima Kakhulu:Lezi zinsimbi ziqinisekiswe ukuthi zisebenza kuzo zonke izinhlobo zokucindezela kanye namazinga okushisa.
Izinzuzo zezinzwa ze-viscosity zesikhathi sangempela, eziku-inthanethi, ezinobukhulu obuningi (ukuqina, ukuhlanganiswa kwedatha)
Ukwamukelwa kwesu lokuzwa okuqondile ngesikhathi sangempela kunikeza umfudlana oqhubekayo wedatha yokuchaza izinto ezibonakalayo, okushintsha ukukhiqizwa kusuka ekuhlolweni kwekhwalithi ngezikhathi ezithile kuya ekulawulweni kwenqubo esebenzayo.
Ukuqapha Okuqhubekayo:Idatha yesikhathi sangempela inciphisa kakhulu ukuthembela ekuhlaziyweni kwelebhu okubambezelekile nokubizayo. Ivumela ukutholakala ngokushesha kokuphambuka kwenqubo okucashile noma ukuhlukahluka kweqoqo ezintweni zokusetshenziswa ezingenayo, okubalulekile ekuvimbeleni izinkinga zekhwalithi ezansi.
Ukugcinwa Okuphansi:Imiklamo ye-resonator eqinile nelinganiselayo yenzelwe ukusetshenziswa isikhathi eside ngaphandle kokulungiswa noma ukucushwa kabusha, okunciphisa isikhathi sokungasebenzi.
Ukuhlanganiswa Kwedatha Okungenamthungo:Izinzwa zesimanje zinikeza ukuxhumana kukagesi okulula ukukusebenzisa kanye nezinqubo zokuxhumana ezijwayelekile embonini, okusiza ukuhlanganiswa okuqondile kwe-viscosity kanye nedatha yokushisa ku-Distributed Control Systems (DCS) ukuze kulungiswe inqubo ezenzakalelayo.
Izindlela Zokukhetha zethuluzi elisetshenziswa ukukala i-viscosity ezigabeni ezahlukene ze-SBR.
Ukukhetha okulungileithuluzi elisetshenziselwa ukukala i-viscositykuncike kakhulu esimweni somzimba sezinto ezibonakalayo endaweni ngayinyeinqubo yokwenza irabha:
Isixazululo/Udaka (i-Reactor):Imfuneko iwukukala i-intrinsic noma i-viscosity ye-slurry ebonakalayo. Ubuchwepheshe buhlanganisa i-Side Stream Rheometers (SSR) ehlaziya njalo amasampula okuncibilika, noma ama-probe e-torsional azwela kakhulu alungiselelwe ukuqapha uketshezi/i-slurry.
Inhlanganisela Enamandla Okuzivumelanisa Nezimo (Ukuxuba):Ukulinganisa okuqondile ngokomzimba akunakwenzeka ngokomshini. Isixazululo esihle kakhulu ukusetshenziswa kwezinzwa ezithambile ezibikezelayo ezihlobanisa ukufakwa kwenqubo okunembile kakhulu (i-torque, ukudonsa kwamandla, izinga lokushisa) kwe-mixer yangaphakathi ne-metric yekhwalithi edingekayo, njenge-Mooney viscosity.
Ukuncibilika kwe-Polymer (Ngaphambi Kokukhushulwa):Ukunqunywa kokugcina kwekhwalithi yokugeleza kudinga inzwa yokucindezela okuphezulu epayipini lokuncibilikisa. Lokhu kungafezwa ngama-probe e-torsional resonator aqinile noma ama-viscometer e-capillary akhethekile angaphakathi (njenge-VIS), angalinganisa i-melt viscosity ebonakalayo ngamanani aphezulu okusika ahlobene nokukhishwa, ngokuvamile ehlobanisa idatha ne-MFR/MVR.
Leli cebo lokuzwa elihlanganisiwe, elihlanganisa izinzwa zehadiwe eziqinile lapho ukugeleza kuvinjelwe khona kanye nezinzwa ezithambile ezibikezelayo lapho ukufinyelela kwemishini kulinganiselwe khona, linikeza ukwakheka kokulawula okuthembekile okudingekayo ukuze kusebenze kahle.ukucutshungulwa kwerabhaukuphathwa.
VII. Ukuqaliswa Okuhlelekile kanye Nokulinganiswa Kwezinzuzo
Amasu Okulawula Ku-inthanethi: Ukusebenzisa ama-loop empendulo ukuze kulungiswe inqubo ezenzakalelayo ngokusekelwe ekubonakaleni kwesikhathi sangempela.
Izinhlelo zokulawula ezenzakalelayo zisebenzisa idatha ye-viscosity yesikhathi sangempela ukudala izikhala zempendulo eziphendulayo, ukuqinisekisa ikhwalithi yomkhiqizo ezinzile nengaguquguquki ngaphezu kwamandla omuntu.
Ukulinganisa Okuzenzakalelayo:Ekuhlanganiseni, uhlelo lokulawula lungaqapha njalo ukuhambisana kwe-compound futhi lulinganise ngokuzenzakalelayo izingxenye ezine-viscosity ephansi, njenge-plasticizers noma i-solvents, ngamanani aqondile lapho kudingeka. Leli cebo ligcina i-viscosity curve ngaphakathi kwebanga lokuqiniseka elichazwe kancane, livimbele ukukhukhuleka.
Ukulawula Okuthuthukisiwe Kokugoba:Ngenxa yokuthi ukuncibilika kwe-SBR akusiyo i-Newtonian futhi kuvame ukuphazamiseka ekukhishweni, abalawuli abajwayelekile be-Proportional-Integral-Derivative (PID) bavame ukunganele ekulawulweni kwe-melt viscosity. Izindlela ezithuthukisiwe, njenge-Active Disturbance Rejection Control (ADRC), ziyadingeka. I-ADRC iphatha ukuphazamiseka kanye nokungalungi kwemodeli njengezinto ezisebenzayo okufanele zenqatshwe, inikeze ikhambi eliqinile lokugcina i-target viscosity kanye nokuqinisekisa ukunemba kobukhulu.
Ukulungiswa Kwesisindo Se-Molecular Dynamic:Ku-reactor ye-polymerization, idatha eqhubekayo evela ku-ithuluzi lokulinganisa i-viscosity yangaphakathiibuyiselwa ohlelweni lokulawula. Lokhu kwenza kube nokulungiswa okulinganiselwe kwesilinganiso sokugeleza komlawuli weketanga, okukhokhela ngokushesha ukuphambuka okuncane kuma-kinetics okusabela nokuqinisekisa ukuthi isisindo sama-molecule se-polymer ye-SBR sihlala ngaphakathi kwebhendi yokucaciswa encishisiwe edingekayo ebangeni elithile le-SBR.
Ukusebenza Kahle Nokuzuza Kwezindleko: Ukulinganisa ukuthuthuka kwezikhathi zomjikelezo, ukunciphisa ukusebenza kabusha, ukusetshenziswa kwamandla kanye nezinto ezibonakalayo okuthuthukisiwe.
Ukutshalwa kwezimali ezinhlelweni ze-rheology eziku-inthanethi kuveza imbuyiselo eqondile nelinganisekayo ethuthukisa inzuzo iyonke yeinqubo yokukhiqiza irabha.
Izikhathi Zomjikelezo Ezilungiselelwe:Ngokusebenzisa ukutholwa kwe-end-point okusekelwe ku-viscosity ku-mixer yangaphakathi, abakhiqizi basusa ingozi yokuxuba ngokweqile. Inqubo evame ukuthembela emijikelezweni eqondile yemizuzu engama-25-40 ingathuthukiswa ukuze ifinyelele ku-viscosity yokusabalala edingekayo ngemizuzu eyi-18-20. Lokhu kushintsha kokusebenza kungaholela ekunciphiseni kwesikhathi somjikelezo ngo-15-28%, okuhunyushwa ngqo ekukhulisweni komthamo kanye nomthamo ngaphandle kokutshalwa kwezimali okusha.
Ukulungiswa Kabusha Nokuchitha Okuncishisiwe:Ukuqapha okuqhubekayo kuvumela ukulungiswa okusheshayo kokuphambuka kwenqubo ngaphambi kokuba kuholele ebuningini bezinto ezingacacisiwe. Leli khono linciphisa kakhulu ukuphinda kusetshenziswe okubizayo kanye nezinto ezilahliwe, okuthuthukisa ukusetshenziswa kwezinto.
Ukusetshenziswa Kwamandla Okuhle:Ngokunciphisa ngokunembile isigaba sokuxuba ngokusekelwe kuphrofayili ye-viscosity yesikhathi sangempela, ukufakwa kwamandla kulungiswa kuphela ukuze kufezwe ukuhlakazeka okufanele. Lokhu kuqeda imfucuza yamandla e-parasitic ehlotshaniswa nokuxuba ngokweqile.
Ukusetshenziswa Kwezinto Ezibonakalayo Ukuzivumelanisa Nezimo:Ukulungiswa kwe-viscosity okuqondiwe kubalulekile lapho kucutshungulwa izitsha zokudla eziguquguqukayo noma ezingezona ezingokoqobo, njenge-polymers ezisetshenzisiwe. Ukuqapha okuqhubekayo kuvumela ukulungiswa okusheshayo kwamapharamitha okuzinzisa inqubo kanye nokulungiswa kwe-viscosity okuqondiwe (isb., ukwandisa noma ukunciphisa isisindo sama-molecule ngezithasiselo) ukuze kuhlangatshezwane ngokuthembekile nezinhloso ze-rheological ezifunwayo, okwandisa ukusetshenziswa kwezinto ezihlukahlukene nezingabizi kakhulu.
Imiphumela yezomnotho inkulu kakhulu, njengoba ifingqiwe kuThebula III.
Ithebula III. Inzuzo Ebikezelwe Yezomnotho Neyokusebenza Evela Ekulawulweni Kokugoba Kwe-inthanethi
| I-Metric | Isisekelo (Ukulawula Okungaxhunyiwe Ku-inthanethi) | Ithagethi (Ukulawula Okuku-inthanethi) | Inzuzo/Umphumela Ongabalwa |
| Isikhathi Somjikelezo Weqembu (Ukuxuba) | Imizuzu engama-25–40 (Isikhathi Esinqunyiwe) | Imizuzu eyi-18–20 (Iphuzu Lokuphela Lokugoba) | Ukwanda okungu-15–28% kokusetshenziswa kwamandla; Ukusetshenziswa kwamandla okuncishisiwe. |
| Izinga Le-Batch Elingacacisiwe | 4% (Izinga Lemboni Elijwayelekile) | <1% (Ukulungiswa Okuqhubekayo) | Kufika ku-75% Ukuncipha Komsebenzi Obusha/Okusalile; Ukulahlekelwa kwezinto zokusetshenziswa okuluhlaza okuncishisiwe. |
| Isikhathi Sokuzinzisa Inqubo (Okufakwayo Okuphinde Kwasetshenziswa) | Amahora (Kudinga ukuhlolwa okuningi kwelebhu) | Amaminithi (Ukulungiswa Okusheshayo kwe-IV/Rheo) | Ukusetshenziswa kwezinto ezisetshenziswayo okuthuthukisiwe; ikhono elithuthukisiwe lokucubungula izitsha zokudla eziguquguqukayo. |
| Ukulungiswa Kwemishini (Ama-Mixer/Extruder) | Ukwehluleka Kokusabela | Ukuqapha Ithrendi Ebikezelayo | Ukutholwa kwamaphutha kusenesikhathi; ukunciphisa isikhathi sokungasebenzi esibi kanye nezindleko zokulungisa. |
Ukulungiswa Okubikezelayo: Ukusebenzisa ukuqapha okuqhubekayo ukuze kutholakale amaphutha kusenesikhathi kanye nezenzo zokuvimbela.
Ukuhlaziywa kwe-viscosity ku-inthanethi kudlulela ngale kokulawula ikhwalithi ukuze kube ithuluzi lokusebenza kahle kanye nokuqapha impilo yemishini.
Ukutholwa Kwephutha:Ukushintsha okungalindelekile kokufundwa kwe-viscosity okuqhubekayo okungenakuchazwa ngokuhlukahluka kwezinto ezingenhla kungasebenza njengesixwayiso sokuqala sokuwohloka komshini ngaphakathi kwemishini, njengokuguguleka kwezikulufo ze-extruder, ukuwohloka kwe-rotor, noma ukuxhuma izihlungi. Lokhu kwenza kube lula ukugcinwa kokuvimbela okusebenzayo nokuhleliwe, kunciphisa ingozi yokwehluleka okubizayo okubizayo.
Ukuqinisekiswa Kwenzwa Ethambile:Idatha yenqubo eqhubekayo, kufaka phakathi amasignali edivayisi kanye nokufakwa kwezinzwa, ingasetshenziswa ukuthuthukisa nokucwengisisa amamodeli okubikezela (izinzwa ezithambile) zezilinganiso ezibalulekile njenge-Mooney viscosity. Ngaphezu kwalokho, le mithombo yedatha eqhubekayo ingasebenza njengendlela yokulinganisa nokuqinisekisa ukusebenza kwamanye amadivayisi okulinganisa ngokomzimba kulayini.
Ukuxilongwa Kokuguquguquka Kwezinto:Ukuthambekela kokuthambekela kokuthambekela kunikeza isendlalelo esibalulekile sokuzivikela ekungahambelani kwezinto zokusetshenziswa ezingabanjwa ukuhlolwa kwekhwalithi okuyisisekelo okungenayo. Ukuguquguquka kwephrofayili yokuthambekela okuqhubekayo kungabonisa ngokushesha ukuguquguquka kwesisindo sama-molecule se-polymer eyisisekelo noma okuqukethwe komswakama okungaguquki noma ikhwalithi kuma-filler.
Ukuqoqwa okuqhubekayo kwedatha eningiliziwe ye-rheological—kokubili evela kuzinzwa eziqondile kanye nezinzwa ezithambile ezibikezelayo—kunikeza isisekelo sedatha sokusungula ukumelwa kwedijithali kwenhlanganisela yerabha. Le sethi yedatha eqhubekayo, yomlando ibalulekile ekwakheni nasekucwengisiseni amamodeli athuthukile aqagela ngokunembile izici zokusebenza komkhiqizo wokugcina eziyinkimbinkimbi, njengezakhiwo ze-viscoelastic noma ukumelana nokukhathala. Leli zinga lokulawula okuphelele liphakamisaithuluzi lokulinganisa i-viscosity yangaphakathikusukela kuthuluzi lekhwalithi elula kuya empahleni eyinhloko yesu yokwenza ngcono ukwakheka kanye nokuqina kwenqubo.
VIII. Isiphetho kanye Nezincomo
Isifinyezo semiphumela ebalulekile mayelana nokulinganiswa kwe-viscosity yerabha.
Ukuhlaziywa kuqinisekisa ukuthi ukuthembela okuvamile ekuhlolweni kwe-rheological okungaqhubeki, okungaxhunyiwe ku-inthanethi (i-Mooney viscosity, i-MFR) kubeka umkhawulo oyisisekelo ekufinyeleleni ukunemba okuphezulu kanye nokwandisa ukusebenza kahle ekukhiqizweni kwe-SBR yesimanje, enomthamo ophezulu. Uhlobo oluyinkimbinkimbi, olungeyona i-Newtonian, kanye ne-viscoelastic lwe-Styrene Butadiene Rubber ludinga ushintsho oluyisisekelo kusu lokulawula—ukuhamba kusuka kuma-metric ephuzu elilodwa, abambezelekile kuya ekuqapheni okuqhubekayo, kwesikhathi sangempela kwe-viscosity ebonakalayo kanye nephrofayili ephelele ye-rheological.
Ukuhlanganiswa kwezinzwa eziqinile, ezakhiwe ngenhloso, ikakhulukazi lezo ezisebenzisa ubuchwepheshe be-torsional resonator, kanye namasu okulawula athuthukile (njengokubona okuthambile okubikezelayo kuma-mixer kanye ne-ADRC kuma-extruders), kwenza kube lula ukulungisa okuzenzakalelayo kuzo zonke izigaba ezibalulekile: ukuqinisekisa ubuqotho besisindo sama-molecule ku-polymerization, ukwandisa ukusebenza kahle kokuhlakazwa kokugcwalisa ngesikhathi sokuxuba, kanye nokuqinisekisa ukuzinza kobukhulu ngesikhathi sokwakheka kokuncibilika kokugcina. Izizathu zomnotho zalolu shintsho lobuchwepheshe ziyathandeka, zinikeza izinzuzo ezingalinganiswa ekuphumeni (ukunciphisa okungu-15-28% esikhathini somjikelezo) kanye nokunciphisa okukhulu ekusetshenzisweni kwe-scrap kanye namandla. Xhumana nethimba lokuthengisa le-RFQ.
