Ukubuka: 51 Umbhali: Isikhathi Sokushicilela Isihleli Sesayithi: 2024-04-25 Umsuka: Isayithi
I-Melamine iyimpahla eluhlaza yamakhemikhali ephilayo ebalulekile, futhi ukusebenzisa kwayo izinto ezihlukahlukene kubonakala kumakhemikhali ayo, ukusetshenziswa kwezimboni ezibanzi, kanye nezingozi zezempilo ezingaba khona.
I-Melamine iyi-powder emhlophe ecwebezelayo enokuqina okushisayo okuphezulu kanye nokumelana namakhemikhali. Ukwakheka kwayo kwamangqamuzana kuqukethe izindandatho ezintathu ze-zine, ezixhunywe ngamabhondi e-carbon nitrogen, okunikeza i-melamine okuqukethwe okuphezulu kwe-nitrogen, okuphinde kube ngesinye sezizathu zokuthi kungani ithandwa kwezinye izinhlelo zokusebenza zezimboni.
I-Melamine inohlu olubanzi lwezicelo zezimboni, ikakhulukazi kulezi zindawo ezilandelayo:
Amapulasitiki nama-resin: I-Melamine ingasetshenziswa ekukhiqizeni ama-laminates, i-tableware yepulasitiki, ama-casings kagesi, njll. Ingathuthukisa ubulukhuni nokugqoka ukumelana kwezinto.
Izingubo zokunamathisela kanye nezinamatheliso: Embonini yokumboza, i-melamine ingasetshenziswa njenge-ejenti yokwelapha ukuze kuthuthukiswe ukumelana nokuklwebheka nokumelana nokushisa kwezingubo. Ezinamathelayo, zingathuthukisa ukunamathela nokuqina.
Ukucutshungulwa kwendwangu kanye nephepha: I-Melamine isetshenziselwa ukwelashwa kwe-flame retardant yezindwangu kanye nokwelashwa okungangeni manzi kwephepha, ukuthuthukisa ukusebenza kwalezi zinto.
Izingozi zempilo
Nakuba i-melamine inohlu olubanzi lwezinhlelo zokusebenza zezimboni, iphinde ihlotshaniswe nezinkinga ezithile zezempilo ezingathi sína. Isigameko esidume kakhulu kwakuyisigameko sango-2008 sokungcoliswa kwempushana yobisi yaseShayina, lapho i-melamine yengezwe ngokungemthetho kumpushana wobisi, okubangele ukuthi izinkulungwane zezingane zigule futhi zikhulise ukukhathazeka komhlaba wonke mayelana nokuphepha kokudla. Ukuchayeka kwethamo elide noma eliphezulu ku-melamine kungase kubangele amatshe ezinso, ukulimala kwezinso, ngisho nomdlavuza.
Ukuze kuvinjelwe izigameko ezifanayo zokuphepha kokudla ukuthi zingaphinde zenzeke, umphakathi wamazwe ngamazwe uqinise ukugada kwawo i-melamine. Amazwe amaningi asungule izindinganiso eziqinile nezinqubo zokuhlola ukuqinisekisa ukuthi okuqukethwe kwe-melamine ekudleni kungaphakathi kwebanga eliphephile. Khonamanjalo, abacwaningi baphinde bafuna ezinye izindlela zokusebenzisa i-melamine ukunciphisa ubungozi obungase bube khona emvelweni nempilo yabantu.
Imvelo ehlukahlukene ye-melamine isikhumbuza ukuthi ngenkathi sijabulela ukunethezeka okulethwa imikhiqizo yamakhemikhali, kudingeka futhi sinake ubungozi obungase bube khona futhi sithathe izinyathelo ezifanele zokuqinisekisa ukuphepha. Ngokuzayo, ngokuthuthuka kobuchwepheshe kanye nokuthuthukiswa kwezinto ezintsha, kulindeleke ukuthi sithole ezinye izindlela eziphephile nezinobungani nemvelo ukuze sizuze intuthuko esimeme.
I-Melamine idlala indima ebalulekile ekukhiqizweni kwepulasitiki, ikakhulukazi ngoba ingathuthukisa ukusebenza kwamapulasitiki, iwenze afaneleke kakhulu izidingo ezithile zohlelo lokusebenza.
I-Melamine isetshenziswa kabanzi ekukhiqizeni imikhiqizo ehlukahlukene yepulasitiki, kufaka phakathi kodwa ingagcini nje:
Ipulasitiki ene-laminated: I-Melamine ivame ukusetshenziswa ekukhiqizeni amapulasitiki alayiniwe. Le nto inokumelana okuhle kakhulu nokugqoka, ukumelana nokushisa, nokumelana namakhemikhali, okwenza ifanele ifenisha, i-flooring, namabhentshi okusebenzela.
I-tableware kanye ne-kitchenware: Ngenxa yokumelana nokushisa nokumelana nokungcola, i-melamine isetshenziselwa ukukhiqiza i-tableware kanye ne-kitchenware, njengezitsha, amapuleti, izinkomishi, njll.
I-casing kagesi: Ipulasitiki eqinisiwe ye-melamine ivame ukusetshenziswa ekukhiqizeni ama-casings kagesi kanye nezingxenye zesakhiwo sangaphakathi ngenxa yezakhiwo zayo ezinhle kakhulu zemishini kanye nokumelana nokushisa.
I-Melamine ayiyona nje into eluhlaza eyinhloko ekukhiqizeni ipulasitiki, kodwa futhi iyingxenye ebalulekile yemboni yokunamathisela.
Emkhakheni wokucubungula izinkuni, i-melamine, njengengxenye eyinhloko ye-adhesives, inemisebenzi elandelayo:
Ukunamathela okuthuthukisiwe: I-Melamine ingasabela ne-formaldehyde ukuze yakhe i-melamine
I-formaldehyde resin, enamathela ngokuqinile futhi ingathuthukisa amandla nokuqina kwemikhiqizo yokhuni.
Ukuthuthukisa ukumelana namanzi: I-Melamine formaldehyde resin inokumelana kahle namanzi, okuvumela imikhiqizo yokhuni eboshiwe ukuthi igcine uzinzo ngisho nasezindaweni ezinomswakama.
Ukuthuthukisa ukumelana nokushisa: Ukumelana nokushisa okuphezulu kwe-melamine formaldehyde resin kuvumela imikhiqizo yokhuni ukuthi igcine ubuqotho besakhiwo ngisho namazinga okushisa aphezulu, okuyenza ifanelekele izindawo ezingaphandle noma ezishisa kakhulu.
Emkhakheni wezolimo, ukusetshenziswa kwe-melamine kugxilwe kakhulu njengesithako somanyolo, ikakhulukazi ekukhiqizeni nasekusetshenzisweni komanyolo we-nitrogen. Okulandelayo ezinye izinhlelo zokusebenza ezithile kanye nemiphumela ye-melamine njengesithako sikamanyolo kwezolimo:
Izithako zomanyolo
Ukusetshenziswa kwe-melamine kumanyolo ikakhulukazi njenge-ejenti yokukhipha kancane i-nitrogen. Ngenxa yokuqukethwe kwayo kwe-nitrogen ephezulu, i-melamine ingasetshenziswa esikhundleni noma isithasiselo somanyolo we-nitrogen ukunikeza isakhi se-nitrogen esidingekayo ekukhuleni kwezitshalo.
Umsizi wokukhulisa isivuno sezitshalo
Umphumela wokukhipha kancane i-nitrogen: I-Melamine ingabola kancane kancane emhlabathini, iqhubeke ikhiphe izakhi ze-nitrogen, futhi inikeze ukutholakala kwezakhi zezitshalo isikhathi eside. Lo mphumela okhishwa kancane usiza izitshalo ukuba zimunce i-nitrogen ngokulinganayo phakathi nayo yonke inkathi yokukhula, ngaleyo ndlela ithuthukise isivuno nekhwalithi yezitshalo.
Ukunciphisa ukuthembela kumanyolo: Ngokusebenzisa i-melamine njengomthombo we-nitrogen, ukuncika kumanyolo wendabuko kungancishiswa, okusiza ukwehlisa izindleko zokukhiqiza ezolimo kanye nokunciphisa izinkinga zemvelo ezibangelwa ukusetshenziswa ngokweqile kukamanyolo, njenge-acidification yenhlabathi kanye ne-eutrophication yamanzi.
Ukuvikelwa kwemvelo: Ukusetshenziswa kwe-melamine kusiza ukunciphisa ukukhishwa kwegesi ebamba ukushisa ngesikhathi sokukhiqiza umanyolo, njengoba ingakhiqizwa emazingeni okushisa aphansi, okuholela ekusetshenzisweni kwamandla okuphansi kanye nomthelela omncane wemvelo uma kuqhathaniswa nokukhiqizwa komanyolo we-nitrogen wezinga lokushisa eliphezulu.
Naphezu kwemiphumela emihle ye-melamine emkhakheni wezolimo, ukuphepha kwayo kusalokhu kuwukucatshangelwa okubalulekile. Njengoba kushiwo emiphumeleni yosesho, uMnyango Wezolimo WaseShayina ukwenqabele ngokusobala ukungezwa okuzenzela kwe-melamine ekudleni, futhi ubeke umkhawulo ongu-2.5mg/kg we-melamine ezintweni ezingavuthiwe zokuphakelayo kanye nemikhiqizo yokudla. Lesi sinyathelo sihlose ukuqinisekisa ikhwalithi nokuphepha kwemikhiqizo yokudla kanye nokuvimbela i-melamine ekubeni yingozi empilweni yabathengi ngokusebenzisa izinsalela zemikhiqizo yezilwane.
Phakathi kuka-2007 no-2008, i-China yabhekana nezigameko ezimbi kakhulu ze-melamine enobisi lwempushana. Imbangela yalesi sigameko ukuthi ezinye izinkampani zobisi zengeze i-melamine ngokungemthetho ukuze kuthuthukiswe ukutholakala kwamaprotheni obisi oluyimpushana. Ngenxa yengxenye yayo ephezulu ye-nitrogen, i-melamine ingasetshenziswa ukwenza amanga imiphumela yokuhlolwa kokuqukethwe kwamaprotheni. Kodwa-ke, i-melamine ayiyona iphrotheni elungele ukugaya komuntu, futhi ukudla isikhathi eside kungabangela ukulimala okukhulu empilweni yomuntu.
Izingozi zempilo: Isigameko sempushana yobisi engcoliswe yi-melamine siye sabangela ukuthi izinkulungwane zezinsana nezingane ezincane zigule, ikakhulukazi ezibonakala njengamatshe ezinso, ukulimala kwezinso, futhi ngisho nezinsana ezimbalwa zafa ngenxa yalokho. Lesi sigameko sivuse ukukhathazeka nokukhathazeka okusabalele ngokuphepha kokudla emhlabeni wonke.
Inkinga yokwethenjwa: Lesi sigameko asizange sibe nomthelela omkhulu embonini yobisi yaseShayina kuphela, kodwa siphinde sabangela ukungathembeki kwabathengi ohlelweni lokulawula ukuphepha kokudla. Le nkinga yokuthembana ayigcini nje kuphela emakethe yasekhaya yaseChina, kodwa futhi ithinta ukwamukelwa kwemikhiqizo yobisi yaseShayina emakethe yamazwe ngamazwe.
Ukuqinisa umthethonqubo: Ngemva kwalesi sigameko, uhulumeni waseShayina waqinisa ukwengamela kwakhe imboni yokudla, waphakamisa izinga lokuphepha kokudla, futhi wasebenzisa izindlela eziqinile zokulawula izinga. Ngaso leso sikhathi, umphakathi wamazwe omhlaba nawo ukhulise imizamo yawo yokuhlola ukudla okuthunyelwa kwamanye amazwe eChina.
Imiphumela yezomthetho: Amabhizinisi ahilelekile kanye nabantu ngabanye babhekana nezijeziso ezinzima ezingokomthetho, okuhlanganisa izinhlawulo, ukushushiswa ngobugebengu, ngisho nokugwetshwa. Lesi sigameko sesiphenduke indaba ebalulekile emlandweni wokuphepha kokudla eShayina, futhi sibe nomthelela omkhulu ekwakhiweni okulandelayo kwemithetho nezinqubomgomo zokuphepha kokudla.
Ngaphezu kwezindaba zokuphepha kokudla, i-melamine ingase futhi ibangele ukungcoliswa kwemvelo. Emkhiqizweni wezimboni, ukusetshenziswa kwe-melamine kungase kuholele ekukhishweni kwe-melamine emanzini angcolile kanye negesi yokukhipha, ngaleyo ndlela kuthinte imvelo yamanzi kanye nekhwalithi yomoya.
Ngaphezu kwalokho, ukuphikelela, ukuhamba, kanye nobuthi obungaba khona (PMT) be-melamine kuyenza ibe ukungcola okusha okukhathazayo emphakathini wezemfundo wamazwe ngamazwe kanye nezinhlangano zezemvelo. Ucwaningo luye lwabonisa ukuthi izinga eliphezulu lokutholwa kanye nezinga lokuhlushwa kwe-melamine ezindaweni zasemanzini kubangela usongo olukhulu ekuvikelekeni kwemithombo yamanzi kanye nemvelo yasemanzini.
Ngokuthuthuka kobuchwepheshe, ubuchwepheshe bokutholwa kwe-melamine nabo buthuthuka njalo. Izindlela zokuthola kusenesikhathi zazincike kakhulu kumasu e-chromatographic aselabhorethri, njenge-chromatography yoketshezi esebenza kahle kanye ne-gas chromatography-mass spectrometry. Nakuba lezi zindlela zinokunemba okuphezulu, zidla isikhathi futhi zidinga opharetha abangochwepheshe kanye nemishini ebizayo. Eminyakeni yakamuva, ubuchwepheshe bokubona ngokushesha obufana ne-near-infrared spectroscopy (NIR) buye bathuthukiswa, obungaqedela ukutholwa ngesikhathi esifushane futhi kube nezindleko zemishini ephansi, okubenza bafanelekele ukuhlolwa ngokushesha endaweni.
Izindlela zokuhlola ilabhorethri ngokuvamile zinembe kakhulu, kodwa amasampula adinga ukuthunyelwa elabhorethri ukuze ahlaziywe. Ezindleleni zokuhlola indawo zigxila kakhulu ekuhlolweni okusheshayo, okungenziwa emapulazini, ezilaheni, noma ezindaweni ezilungisa ukudla ukuze kutholakale izinkinga ngokushesha futhi kuthathwe izinyathelo.
Ukusebenza okuphezulu kwe-liquid chromatography (HPLC): ilungele ukuhlaziywa kwekhwalithi nenani lamasampuli ayinkimbinkimbi, ngokunemba okuphezulu kodwa izindleko eziphezulu.
I-Gas chromatography-mass spectrometry (GC-MS): ifanele ukuhlaziya amasampula aguquguqukayo nazinzile ngokushisa okushisayo, ehlinzeka ngolwazi lwesakhiwo sezinhlanganisela.
Ikhadi lokuthola ngokushesha: Ngokusebenzisa ubuchwepheshe be-immunochromatography, ukuba khona kwe-melamine kungasheshe kubonakale, kuyenze ifanelekele ukuhlolwa kokuqala endaweni.
I-spectrometer ephathekayo: njenge-spectrometer eseduze ne-infrared, ingakwazi ukubona ngokushesha ngaphandle kwesidingo sokucutshungulwa kwangaphambili okuyinkimbinkimbi.
Ngemuva kwesigameko se-melamine, iziphathimandla zamazwe ngamazwe nezasekhaya ziye zaqinisa ukugada kwazo ukuphepha kokudla, ikakhulukazi ukulawulwa kwe-melamine.
Izinyathelo zokulawula zamazwe ngamazwe
I-Codex Alimentarius Commission (CAC) isungule amazinga omkhawulo we-melamine ekudleni ukuze kuvikelwe impilo yabathengi.
I-EU ibeke umkhawulo wezinsalela eziphezulu ze-melamine emikhiqizweni yobisi ethengwa kwamanye amazwe isuka e-China.
UMnyango Wezempilo waseShayina kanye neminye iminyango emihlanu bakhiphe isaziso samanani aphezulu omkhawulo we-melamine ekudleni, ukubeka imingcele ye-melamine kufomula yezingane nokunye ukudla.
I-General Administration of Quality Supervision, Inspection and Quarantine of China ihlele ukuhlolwa okukhethekile kazwelonke kwe-melamine obisini oluwuketshezi ukuze kuqinisekiswe ukuphepha kobisi oluwuketshezi emakethe.
Ukusetshenziswa kwe-melamine kulethe izinselelo eziningi namathuba embonini. Inselele isekutheni ungaqinisekisa kanjani ukusetshenziswa kwayo ngokuphephile ezindaweni ezingadlanga futhi kuvinjwe izigameko ezifanayo zokuphepha kokudla ukuthi zingaphinde zenzeke. Lokhu kudinga ukugadwa okuqinile kanye nezinyathelo zokulawula kuzo zonke izigaba kusukela ekukhiqizeni, ekugcinweni, ekuthuthweni kuya ekusetshenzisweni kokugcina. Ithuba lisekuthuthukiseni izindawo ezintsha zokufaka izicelo ngokusungula izinto ezintsha zobuchwepheshe, njengokukhiqizwa kwezinto ezivikela imvelo, kanye nokwenza ngcono ukusebenza nokuphepha kwemikhiqizo ekhona.
Ukuqamba okusha kwezobuchwepheshe kuyisihluthulelo sokuthuthukiswa kwesikhathi esizayo kwe-melamine. Ngokwenza ngcono inqubo yokukhiqiza, izingozi zemvelo ngesikhathi sokukhiqizwa kwe-melamine zingancishiswa, kuyilapho kuthuthukisa ikhwalithi nokuphepha komkhiqizo. Isibonelo, ukuthuthukisa ama-catalyst amasha kanye nezimo zokusabela ukuze kuncishiswe ukukhiqizwa kwemikhiqizo futhi kuthuthukise ukuhlanzeka kwe-melamine. Ukulawulwa kobungozi kuhilela ukuhlonza, ukuhlola, nokulawula izingozi ezingaba khona ngesikhathi kusetshenziswa i-melamine, okuhlanganisa nokuvikela impilo yabasebenzi kanye nemvelo.
Ngenxa yomthelela omubi we-melamine ezenzakalweni zokuphepha kokudla, ukuthola ezinye izindlela sekugxilwe ocwaningweni. Izinto ezishintshayo zidinga ukuba nezakhiwo ezifanayo zomzimba namakhemikhali, kodwa kufanele ziphephe futhi zibe nobungane ngokwemvelo. Isibonelo, izinhlanganisela ezisekelwe ensimbi ezifana ne-zinc stannate, i-zinc borate, ne-aluminium diethylphosphinate ziye zacutshungulwa njengokuthatha indawo ye-melamine kwezinye izinhlelo zokusebenza. Ngaphezu kwalokho, i-melamine polyphosphate nayo iyahlolwa ukuze ithathele indawo i-melamine emikhakheni efana ne-flame retardants.
Izinto ezintsha ezigxile emvelweni nezempilo ziyizindlela ezibalulekile zokuthuthukiswa kwesikhathi esizayo. Ngokugcizelelwa komhlaba wonke ekuvikelweni kwemvelo kanye nentuthuko esimeme, ukuthuthukiswa kwezinto ezintsha ezingenabo ubuthi, ezibolayo, nezisimeme sekuphenduke indawo yocwaningo. Lezi zinto ezintsha azidingi nje kuphela ukuhlangabezana nezidingo zokusebenza kwezicelo zezimboni, kodwa futhi zihlangabezana nezindinganiso eziqinile zemvelo ukuze kuncishiswe umthelela wazo emvelweni nempilo yabantu. Isibonelo, ukuthuthukiswa kwamapulasitiki asekelwe ku-bio nezinto ezibolayo kuhloswe ngazo ukunciphisa ukungcoliswa kwemvelo okubangelwa amapulasitiki endabuko.
I-Melamine, njengekhemikhali esebenza ngezinto eziningi, idlala indima ebalulekile emkhakheni wezimboni, ikakhulukazi ekukhiqizeni amapulasitiki, okokunamathela, nama-adhesive. Okuqukethwe kwayo kwe-nitrogen ephezulu kuyenza ibe yisisetshenziswa esibalulekile sokuthuthukisa ukusebenza komkhiqizo, ikakhulukazi ekukhiqizeni izinto ezikwazi ukumelana nokushisa, ukumelana nokuklwebheka, nezingashisi amalangabi. Kodwa-ke, ukusetshenziswa kwe-melamine akunazo izingozi, ikakhulukazi emkhakheni wokuphepha kokudla, futhi izinkinga zezempilo ezibangelwa ukungezwa kwayo okungekho emthethweni ziye zaheha ukunakwa komhlaba wonke.
Kusukela ku-2008 isigameko sokungcoliswa kobisi lwase-China, siyabona ukuthi uma i-melamine isetshenziswe ngokungemthetho ekudleni, ingase ibe usongo olukhulu empilweni yomphakathi. Lesi sigameko sibonisa ukubaluleka kokulawulwa kokuphepha, okungadingi imithetho nezindinganiso eziqinile kuphela zokulawula ukukhiqizwa nokusetshenziswa kwe-melamine, kodwa futhi nezindlela zokulawula eziphumelelayo zokuqinisekisa ukuqaliswa kwale mithethonqubo.
Ukuze kuncishiswe ubungozi be-melamine, ukusungulwa kwezobuchwepheshe kanye nocwaningo kwezinye izindlela sekugxilwe ekuthuthukisweni kwemboni. Ngokuthuthukisa izinqubo zokukhiqiza nokuthuthukisa ezinye izinto ezintsha, umthelela endaweni nempilo ungancishiswa kuyilapho kugcinwa ukusebenza komkhiqizo. Ngesikhathi esifanayo, ukuqinisa ilabhorethri kanye namasu okuhlola endaweni angakwazi ukubona ngesikhathi futhi avimbele ukusetshenziswa okungalungile kwe-melamine.
Ngamafuphi, ukuthuthukiswa kwesikhathi esizayo kwe-melamine kuncike ekuqondeni okuphelele kokusetshenziswa kwayo nezingozi, kanye nokuqiniswa okuqhubekayo kokugadwa kokuphepha. Ngokusungula izinto ezintsha nokubambisana kwamazwe ngamazwe, singabheka phambili ekusaseni eliphephile nelinobungani kwemvelo embonini yamakhemikhali.
