Ukubunjwa okujikelezayo(BrEukubumba) ibandakanya ukungunda okushushu okuzaliswe yintlawulo okanye ubunzima bokudubula bemathiriyeli.Emva koko ijikeleziswa ngokucothayo (ngokuqhelekileyo ijikeleze ii-axes ezimbini ze-perpendicular) ibangela ukuba izinto ezithambileyo zisasazeke kwaye zibambelele kwiindonga zobumba.Ukuze kugcinwe ubukhulu obulinganayo kuyo yonke indawo, ukungunda kuyaqhubeka ukujikeleza ngawo onke amaxesha ngexesha lesigaba sokufudumeza kunye nokunqanda ukuntywila okanye ukuguquka kwakhona ngexesha lesigaba sokupholisa.Inkqubo yasetyenziswa kwiiplastiki kwiminyaka yee-1940 kodwa kwiminyaka yokuqala yayingasetyenziswanga kangako kuba yayiyinkqubo ecothayo eyayithintelwe kwinani elincinci leeplastiki.Kwiminyaka engamashumi amabini edlulileyo, ukuphuculwa kolawulo lwenkqubo kunye nophuhliso kunye nomgubo weplastiki kubangele ukwanda okukhulu kokusetyenziswa.
I-Rotocasting (ekwaziwa ngokuba yi-rotacasting), ngokuthelekisa, isebenzisa i-resin eziziphilisayo kwi-mold engatshisiyo, kodwa yabelana ngezantya ezicothayo ezijikelezayo ezifanayo kunye nokubumba okujikelezayo.I-spincasting akufuneki ibhidaniswe nayo, kusetyenziswa iireyini eziziphilisayo okanye intsimbi emhlophe kumatshini wokuphosa we-centrifugal onesantya esiphezulu.
Imbali
Ngowe-1855 uR. Peters waseBritani wabhala ukusetyenziswa kokuqala kwe-biaxial rotation kunye nobushushu.Le nkqubo yokubumba ejikelezayo yayisetyenziselwa ukudala amaqokobhe entsimbi yentsimbi kunye nezinye iinqanawa ezingenanto.Injongo ephambili yokusebenzisa ukubunjwa okujikelezayo kwakukudala ukuhambelana kwindonga kunye nobuninzi.Ngo-1905 eUnited States i-FA Voelke yasebenzisa le ndlela yokugrumba izinto ze-wax.Oku kukhokelele kwinkqubo ye-GS Baker's kunye ne-GW Perks yokwenza amaqanda etshokolethi angenamngxuma ngo-1910. Ukubumba okujikelezayo kwaphuhliswa ngakumbi kwaye u-RJ Powell wasebenzisa le nkqubo yokubumba udaka lwe-Paris ngo-1920s.Ezi ndlela zakuqala zisebenzisa izixhobo ezahlukeneyo zalathisa ukuqhubela phambili kwindlela ukubumba okujikelezayo kusetyenziswa namhlanje ngeeplastiki.
Iiplastiki zaziswa kwinkqubo yokubumba ejikelezayo ekuqaleni kweminyaka yoo-1950.Esinye sezicelo zokuqala yayikukuvelisa iintloko zoonodoli.Oomatshini benziwe ngomatshini we-oveni we-E Blue webhokisi, ophefumlelwe yi-axle yangemva ye-General Motors, eqhutywa yinjini yombane yangaphandle kwaye ifudunyezwe zizitshisi zegesi ezinyuswe emgangathweni.Umngundo wenziwa nge-electroformed nickel-copper, kwaye iplastiki yayilulwelo lwePVC plastisol.Indlela yokupholisa yayiquka ukubeka umngundo emanzini abandayo.Le nkqubo yokubumba okujikelezayo yakhokelela ekudalweni kwezinye iithoyi zeplastiki.Njengoko imfuno kunye nokuthandwa kwale nkqubo kusanda, yasetyenziswa ukwenza ezinye iimveliso ezifana ne-cones zendlela, ii-buoys zaselwandle, kunye neendawo zokuhlala zemoto.Oku kuthandwa kwakhokelela ekuphuhlisweni koomatshini abakhulu.Inkqubo entsha yokufudumeza nayo yenziwa, ukusuka kwiijethi zerhasi ezithe ngqo ukuya kwinkqubo yomoya yesantya esiphezulu esingathanga ngqo sangoku.EYurophu ngexesha le-1960 inkqubo ye-Engel yaphuhliswa.Oku kwavumela ukudala izitya ezinkulu ezingenanto ukuba zenziwe kwi-polyethylene ephantsi.Indlela yokupholisa ibibandakanya ukucima izitshisi kunye nokuvumela iplastiki ukuba lukhuni ngelixa isashukuma ekubunjeni.[2]
Ngo-1976, i-Association of Rotational Moulders (ARM) yaqalwa eChicago njengombutho worhwebo wehlabathi jikelele.Injongo ephambili yalo mbutho kukwandisa ulwazi malunga neteknoloji yokubumba kunye nenkqubo.
Kwiminyaka yee-1980, iiplastiki ezintsha, ezifana ne-polycarbonate, i-polyester, kunye ne-nylon, zaziswa ekubunjweni okujikelezayo.Oku kukhokelele ekusetyenzisweni okutsha kwale nkqubo, njengokudalwa kweetanki zepetroli kunye nokubunjwa kwamashishini.Uphando olwenziweyo ukususela ekupheleni kweminyaka yoo-1980 kwiYunivesithi yaseQueen yaseBelfast lukhokelele ekuphuhliseni ukubekwa esweni okuchanekileyo ngakumbi kunye nolawulo lweenkqubo zokupholisa ezisekelwe kuphuhliso lwabo “lwenkqubo yeRotolog”.
Izixhobo kunye nezixhobo
Oomatshini bokubumba abajikelezayo benziwa kuluhlu olubanzi lobukhulu.Ngokuqhelekileyo zibandakanya ukungunda, i-oven, igumbi lokupholisa, kunye ne-spindles yokungunda.I-spindles ifakwe kwi-axis ejikelezayo, enika i-coating efanayo yeplastiki ngaphakathi kwesikhunta ngasinye.
Ukungunda (okanye izixhobo zokusebenza) mhlawumbi zenziwe ngentsimbi edityanisiweyo okanye eyenziwe ngentsimbi.Indlela yokwenziwa isoloko iqhutywa yinxenye yobungakanani kunye nobunzima;uninzi lwamalungu antsonkothileyo kusenokwenzeka ukuba zenziwe ngezixhobo ezityhidiweyo.Iimbumba zenziwa ngentsimbi engenasici okanye ialuminiyam.Iimbumba ze-aluminiyam zidla ngokuba ngqindilili kunobumba obulinganayo bentsimbi, njengoko iyintsimbi ethambileyo.Obu bunzima abuchaphazeli amaxesha omjikelezo ngokubalulekileyo kuba i-aluminiyam ye-thermal conductivity iphindwe kaninzi kunentsimbi.Ngenxa yesidingo sokuphuhlisa imodeli phambi kokubunjwa, iimbumba ezityhidiweyo zivame ukuba neendleko ezongezelelweyo ezinxulumene nokuveliswa kwesixhobo, ngelixa intsimbi eyenziwe ngentsimbi okanye i-aluminium molds, ngakumbi xa isetyenziselwa iindawo ezincinci ezincinci, zingabizi kakhulu.Nangona kunjalo, ezinye iimbumba ziqulethe zombini i-aluminium kunye nentsimbi.Oku kuvumela ukuguquguquka okuguquguqukayo kwiindonga zemveliso.Ngelixa le nkqubo ingachanekanga njengokubumba inaliti, ibonelela umyili ngokhetho oluninzi.Ukongezwa kwe-aluminiyam kwintsimbi kunika amandla amaninzi okushisa, okubangela ukuba ukunyibilika-ukuhamba kuhlale kwindawo yolwelo ixesha elide.
Ixesha lokuposa: Aug-04-2020