Ukubumba Okujikelezayo(BrEukubumba) kuhilela isikhunta esishisayo esingenalutho esigcwaliswa ngeshaja noma isisindo sokudubula sempahla. Bese ijikeleziswa kancane (imvamisa izungeza izimbazo ezimbili eziqondile) okubangela ukuthi izinto ezithambile zihlakazeke futhi zinamathele ezindongeni zesikhunta. Ukuze kugcinwe ukujiya okulinganayo kuyo yonke ingxenye, isikhunta siyaqhubeka nokujikeleza ngaso sonke isikhathi phakathi nesigaba sokushisa futhi sigweme ukuwohloka noma ukuwohloka futhi nangesikhathi sesigaba sokupholisa. Le nqubo yasetshenziswa kumapulasitiki ngeminyaka yawo-1940 kodwa eminyakeni yokuqala yayingasetshenzisiwe kangako ngoba yayihamba kancane ilinganiselwe enanini elincane lamapulasitiki. Emashumini amabili eminyaka adlule, ukuthuthukiswa kokulawulwa kwenqubo kanye nentuthuko ngezimpushana zepulasitiki kubangele ukwanda okukhulu kokusetshenziswa.
I-Rotocasting (ebuye yaziwe ngokuthi i-rotacasting), ngokuqhathanisa, isebenzisa ama-resin ezilaphayo esikhunjeni esingashisi, kodwa yabelana ngesivinini esinesivinini sokujikeleza okufanayo nokubumba okujikelezayo. I-spincasting akufanele kudidaniswe nakho kokubili, ukusebenzisa izinsalela ezizilaphayo noma insimbi emhlophe emshinini wokuphonsa we-centrifugal onesivinini esikhulu.
Umlando
Ngo-1855 uR. Peters waseBrithani wabhala ukusetshenziswa kokuqala kokujikeleza kwe-biaxial nokushisa. Le nqubo yokubumba ejikelezayo yayisetshenziselwa ukwakha amagobolondo ensimbi nezinye izitsha ezingenalutho. Inhloso eyinhloko yokusebenzisa ukubunjwa okujikelezayo kwakuwukudala ukuvumelana kokuqina kodonga kanye nokuminyana. Ngo-1905 e-United States u-FA Voelke wasebenzisa le ndlela yokugebha izinto ze-wax. Lokhu kwaholela kunqubo ka-GS Baker kanye ne-GW Perks yokwenza amaqanda kashokholethi angenalutho ngo-1910. Ukubumba okujikelezayo kwathuthukiswa futhi u-RJ Powell wasebenzisa le nqubo yokubumba ukhonkolo wase-Paris ngawo-1920s. Lezi zindlela zakuqala zisebenzisa izinto ezahlukahlukene zaqondisa intuthuko endleleni ukubumba okujikelezayo okusetshenziswa ngayo namuhla ngamapulasitiki.
Ipulasitiki yethulwa ohlelweni lokubumba olujikelezayo ekuqaleni kwawo-1950. Esinye sezicelo zokuqala kwakuwukukhiqiza amakhanda onodoli. Lo mshini wenziwe ngomshini webhokisi kahhavini we-E Blue, ogqugquzelwe i-axle yangemuva yakwaGeneral Motors, enikwa amandla yinjini kagesi yangaphandle futhi ishisiswe izishisi zegesi ezibekwe phansi. Isikhunta senziwe nge-electroformed nickel-copper, kanti ipulasitiki yayiwuketshezi lwePVC plastisol. Indlela yokupholisa yayihlanganisa ukubeka isikhunta emanzini abandayo. Le nqubo yokubumba ngokuzungezayo yaholela ekwakhiweni kwamanye amathoyizi epulasitiki. Njengoba isidingo nokuthandwa kwale nqubo kwanda, yasetshenziselwa ukwakha eminye imikhiqizo efana nezigaxa zomgwaqo, ama-buoy olwandle, kanye nezindawo zokubeka izingalo zezimoto. Lokhu kuduma kwaholela ekuthuthukisweni kwemishini emikhulu. Kwaphinde kwadalwa uhlelo olusha lokushisisa, olusuka kumajethi egesi aqondile aye ohlelweni lwamanje lomoya wesivinini esiphezulu esingaqondile. EYurophu ngeminyaka yawo-1960 kwasungulwa inqubo ye-Engel. Lokhu kwavumela ukudalwa kweziqukathi ezinkulu ezingenalutho ukuthi zidalwe ku-polyethylene ephansi. Indlela yokupholisa yayihlanganisa ukucisha izimbawula nokuvumela ipulasitiki ukuthi iqine ngenkathi inyakazisa esibunjeni.[2]
Ngo-1976, i-Association of Rotational Moulders (ARM) yaqalwa eChicago njengenhlangano yomhlaba wonke yabahwebi. Inhloso eyinhloko yale nhlangano ukukhulisa ukuqwashisa ngobuchwepheshe bokubumba obujikelezayo kanye nenqubo.
Ngawo-1980, amapulasitiki amasha, njenge-polycarbonate, i-polyester, ne-nylon, aqalwa ekubunjweni okujikelezayo. Lokhu kuholele ekusetshenzisweni okusha kwalolu hlelo, njengokwakhiwa kwamathangi kaphethiloli kanye nokubumba kwezimboni. Ucwaningo olwenziwa kusukela ngasekupheleni kwawo-1980 e-Queen's University Belfast luholele ekuthuthukisweni kokuqapha okunembe kakhudlwana nokulawulwa kwezinqubo zokupholisa ngokusekelwe ekuthuthukisweni kwabo “kohlelo lweRotolog”.
Izisetshenziswa kanye namathuluzi
Imishini yokubumba ejikelezayo yenziwa ngobukhulu obuhlukahlukene. Ngokuvamile ahlanganisa isikhunta, ihhavini, ikamelo lokupholisa, nezinsimbi zokuphotha isikhunta. Ama-spindle afakwe ku-axis ejikelezayo, ehlinzeka nge-coating efanayo yepulasitiki ngaphakathi kwesikhunta ngasinye.
Isikhunta (noma i-tooling) yenziwa ngensimbi yeshidi elishiselwe noma i-cast. Indlela yokukhiqiza ivame ukuqhutshwa usayizi wengxenye kanye nobunzima; izingxenye eziningi eziyinkimbinkimbi cishe zenziwe ngezinto ezisetshenziswayo. Isikhunta ngokuvamile sikhiqizwa ngensimbi engagqwali noma i-aluminium. Ukubunjwa kwe-aluminium kuvame ukujiya kakhulu kunesikhunta sensimbi esilinganayo, njengoba kuyinsimbi ethambile. Lokhu ukujiya akuthinti izikhathi zomjikelezo ngokuphawulekayo njengoba i-thermal conductivity ye-aluminium inkulu ngokuphindwe kaningi kunensimbi. Ngenxa yesidingo sokuthuthukisa imodeli ngaphambi kokulingisa, isikhunta esisansimbi sivame ukuba nezindleko ezengeziwe ezihambisana nokukhiqizwa kwamathuluzi, kuyilapho isikhunta esakhiwe ngensimbi noma i-aluminium, ikakhulukazi uma sisetshenziselwa izingxenye eziyinkimbinkimbi, zibiza kancane. Kodwa-ke, ezinye isikhunta ziqukethe kokubili i-aluminium nensimbi. Lokhu kuvumela ukujiya okuguquguqukayo ezindongeni zomkhiqizo. Yize le nqubo ingaqondile njengokubumba komjovo, ihlinzeka umklami ngezinketho eziningi. Ukwengezwa kwe-aluminium ensimbi kunikeza umthamo wokushisa owengeziwe, okwenza ukuncibilika kuhlale kusesimweni soketshezi isikhathi eside.
Isikhathi sokuthumela: Aug-04-2020