I-embryo yebhodlela lepulasitiki iyindlela yokuqala enqubweni yokukhiqiza amabhodlela epulasitiki. Imingcele yayo efana nosayizi, intambo kanye nesisindo ibalulekile futhi ihlobene ngqo nokusetshenziswa kanye nokusebenza kwebhodlela.
1. Ubudlelwano phakathi kwekhwalithi ye-preform kanye nekhwalithi yezinto ze-PET
I-Polyethylene terephthalate (PET) ibizwa ngokuthi i-polyester. Ukukhiqizwa kwamabhodlela epulasitiki e-PET kungahlukaniswa kube ukubumba kwe-injection stretch blow (okufingqiwe ngokuthi ukubumba kwe-injection stretch blow) kanye nokubumba kwe-extrusion stretch blow (okufingqiwe ngokuthi ukubumba kwe-extrusion stretch blow) ngokwezindlela ezahlukene. Kulezi zindlela ezimbili zokubumba, inqubo yokubumba i-injection stretch blow kulula ukuyilawula, inokusebenza kahle kokukhiqiza okuphezulu, futhi inokungcola okuncane, futhi ivame kakhulu.
Uma ulungiselela amabhodlela afakwe umoya, izingcezu ze-PET zifakwa kuqala ku-preform. Kudinga ukuthi ingxenye yezinto ezisetshenziswa kabusha zesibili ingabi phezulu kakhulu (ngaphansi kuka-5%), inani lezikhathi zokusebenzisa kabusha akufanele lidlule izikhathi ezimbili, futhi isisindo sama-molecule kanye ne-viscosity akufanele kube phansi kakhulu (isisindo sama-molecule 31000-50000, i-viscosity yangaphakathi engu-0.78-0.85 cm3/g). Ngokusho koMthetho Kazwelonke Wokuphepha Kokudla, ukusetshenziswa kwezinto ezisetshenziswa kabusha zesibili ekupakisheni ukudla nemithi akuvunyelwe. Ama-preform afakwe umjovo adinga ukugcinwa isikhathi esingaphezu kwamahora angama-24 ngaphambi kokusetshenziswa. Ama-preform angasetshenziswanga ngemva kokushisa kumele agcinwe isikhathi esingaphezu kwamahora angama-48 ngaphambi kokuba aphinde afudumale. Isikhathi sokugcina sebhodlela akufanele sidlule izinyanga eziyisithupha.
Ikhwalithi ye-preform incike kakhulu kwikhwalithi yezinto ze-PET, ngakho-ke kuyadingeka ukukhetha izinto ezilula ukuzifutha nokwakha, bese kwakha inqubo efanele yokwakha i-preform. Ukuhlolwa kubonisa ukuthi ama-preform e-PET ane-viscosity efanayo kulula ukuwafutha isikhunta ngezinto zokusetshenziswa ezingenisiwe kunezinto zokusetshenziswa zasekhaya. Kodwa-ke, iqembu elifanayo lama-preform lingase libe nezinqubo ezahlukene zokufutha nge-blow ngezinsuku zokukhiqiza ezahlukene. Ikhwalithi ye-preform inquma ubunzima benqubo yokufutha nge-blow. Izidingo ze-preform ubumsulwa, ukucaca, ukungabi nakungcola, ukungabi nombala, ubude obufanele bephuzu lomjovo, kanye ne-halo nxazonke.
Ukushisa kwe-preform kuqedwa yi-oven yokushisa, futhi izinga lokushisa layo lisethwa ngesandla futhi lilungiswe ngokuzenzakalelayo. Ku-oven, izibani ze-far-infrared zikhipha imisebe ye-far-infrared ukuze zikhiphe ukushisa kuma-preform, kanti ifeni engezansi kwe-oven yenza ukujikeleza kokushisa ukuze yenze izinga lokushisa ku-oven lifane. Ama-preform ajikeleza ngenkathi eqhubekela phambili ku-oven, ukuze udonga lwe-preform lufudumale ngokulinganayo.
Ukuhlelwa kwezibani kuhhavini ngokuvamile kusesimweni "sendawo" kusukela phezulu kuya phansi, kanti eziningi zisemaphethelweni amabili futhi zincane phakathi. Ukushisa kwehhavini kulawulwa yinani lezibani ezivuliwe, ukusetha izinga lokushisa lilonke, amandla ehhavini kanye nesilinganiso sokushisa sesigaba ngasinye. Ukuvulwa kwepayipi lesibani kufanele kulungiswe kuhlanganiswe nokuqhuma kwebhodlela ngaphambi kokuqhuma. Ukuze ihhavini isebenze kangcono, ukulungiswa kokuphakama kwayo, ipuleti lokupholisa, njll. kubaluleke kakhulu. Uma ukulungiswa kungafanele, amaphutha anjengokuvuvuka komlomo webhodlela (umlomo webhodlela uba mkhulu) kanye nentamo eqinile (izinto zentamo azikwazi ukudonswa zivuleke) zivame ukwenzeka ngesikhathi sokubumba.
2. Izici ezibalulekile ekwakhiweni kwama-embryo ebhodleleni
Ama-preform epulasitiki ayifomu lokuqala lamabhodlela epulasitiki enqubweni yokukhiqiza. Amapharamitha awo njengosayizi, intambo kanye nesisindo abalulekile futhi ahlobene ngqo nenhloso kanye nokusebenza kwebhodlela.
Okokuqala, ubukhulu be-preform bubalulekile esitsheni sokugcina sokupakisha. Lapho sinquma ubukhulu be-preform, kufanele siqale sicabangele injongo yebhodlela. Ingabe lingokudla, iziphuzo, izimonyo noma ezinye izinkambu? Ukusetshenziswa okuhlukile kungadinga amabhodlela anezimo namakhono ahlukene. Ngokucabangela ngokucophelela izidingo zomthamo womkhiqizo, umthamo we-preform unganqunywa futhi isimo esifanele singakhethwa, njengesiyingi, isikwele noma i-oval.
Okwesibili, intambo (i-caliber) ibhekisela kububanzi bomlomo webhodlela futhi iyipharamitha ebalulekile. Ukulinganisa intambo kuqinisekisa ukuthi ukulinganisa kuqondile ukuze kutholakale usayizi we-caliber onembile. Usayizi wentambo uthinta ngqo umphumela wokugcwalisa nokuthulula ibhodlela. Imikhiqizo ehlukene ingadinga osayizi abahlukene bezintambo, ngakho-ke lapho uklama ibhodlela, ukukhetha intambo okunengqondo kuyadingeka.
Okokugcina, isisindo segremu se-preform sibhekisela esisindweni sebhodlela, okuhlanganisa nomzimba webhodlela kanye nomlomo webhodlela. Isisindo segremu sebhodlela singalinganiswa ngokunembile ngokukala noma ngokusebenzisa isikali esijikelezayo. Ukunqunywa kwesisindo segremu kuhlobene ngqo namandla nokuqina kwebhodlela. Uma ucabangela isisindo, kubalulekile ukulinganisela amandla esakhiwo sebhodlela kanye nezindleko zezinto zokwakha ukuqinisekisa ukuthi umkhiqizo wokugcina unamandla anele futhi uhlangabezana nezidingo zokonga.
Sekukonke, usayizi, intambo kanye nesisindo se-preform kuyizinto ezibalulekile okufanele zicatshangelwe esigabeni sokuklama ibhodlela lepulasitiki. Ngokulinganisa ngokucophelela kanye nokukhetha okunengqondo, kungaqinisekiswa ukuthi ibhodlela lokugcina lihlangabezana nezidingo zomkhiqizo kanye nezindinganiso zomkhakha futhi linikeza ukusebenza okuhle kakhulu kokupakisha. Ngesikhathi senqubo yokukhiqiza amabhodlela, ukunaka okuqhubekayo ekulawulweni kwalezi zinhlaka kuzosiza ekukhiqizeni amabhodlela epulasitiki asezingeni eliphezulu.
Isikhathi sokuthunyelwe: Mashi-27-2025