Shell isikhunta thusiinqubo lapho isihlabathi esihlanganiswe ne-resin ye-thermosetting sivunyelwe khona ukuxhumana nepuleti lephethini yensimbi evuthayo, ukuze kwakheke igobolondo elincanyana futhi eliqinile lesikhunta elizungeze i-pattem. Ngemuva kwalokho igobolondo liyasuswa kuphethini bese ukubhekana nakho nokuhudula kuyasuswa ndawonye bese kugcinwa kuflask ngezinto ezidingekayo zokubuyisela emuva bese insimbi encibilikisiwe ithelwa kusikhunta.
Ngokuvamile, isihlabathi esomile futhi esihle (90 kuya ku-140 GFN) esingenalo ngokuphelele ubumba sisetshenziselwa ukulungisa isihlabathi sokubumba igobolondo. Usayizi wokusanhlamvu ozokhethwa uncike ekugcineni komhlaba okufunwayo ekusakazweni. Kuhle kakhulu usayizi wokusanhlamvu kudinga inani elikhulu le-resin, okwenza isikhunta sibize.
Izinhlaka zokwenziwa ezisetshenziswa ekubunjweni kwegobolondo empeleni ziyizinhlaka ze-thermosetting, ezenza lukhuni ngokungenakulungiseka ngokushisa. Izinhlaka ezisetshenziswa kakhulu zingama-phenol formaldehyde resins. Kuhlanganiswe nesihlabathi, banamandla aphakeme kakhulu nokumelana nokushisa. Izinhlayiya ze-phenolic ezisetshenziswa ekubunjweni kwegobolondo ngokuvamile ziwuhlobo lwesigaba sesibili, okungukuthi, i-resin ine-phenol eyeqile futhi isebenza njenge-thermoplastic material. Ngesikhathi sokumboza nesihlabathi i-resin ihlanganiswa ne-catalyst efana ne-hexa methylene tetramine (hexa) engxenyeni engaba ngu-14 kuye ku-16% ukuze kuthuthukiswe izici ze-thermosetting. Izinga lokushisa eliphilayo lalokhu lizoba cishe ngo-150 C kanti isikhathi esidingekayo kungaba amasekhondi angama-50 kuye kwangama-60.
Izinzuzo zeShell Mold Casting Process
1. Shell-isikhunta castings ngokuvamile anembe ngokwedlula ubukhulu kunokusakazwa kwesihlabathi. Kungenzeka ukuthola ukubekezelelana okungu- + 0.25 mm kokuphonsa insimbi kanye +0. Ama-35 mm wokuphonsa izinsimbi ezimpunga ngaphansi kwezimo ezijwayelekile zokusebenza. Endabeni yesikhunta segobolondo esiseduze, umuntu angasithola kububanzi obungu- + 0,03 kuye +0.13 mm ngezinhlelo ezithile.
2. Indawo ebushelelezi ingatholakala ekubunjweni kwegobolondo. Lokhu kutholakala ikakhulu ngosayizi ocolekile osetshenzisiwe. Ububanzi obujwayelekile bokuba noburhabaxa bokuhleleka kwezibuko ezi-3 kuye kwezi-6.
3. Ama-engeli okusalungiswa, angaphansi kokuphonswa kwesihlabathi, ayadingeka ekubunjweni kwegobolondo. Ukwehliswa kwama-engeli okusalungiswa kungahle kusuka ku-50 kuye ku-75%, okusindisa kakhulu izindleko zezinto ezibonakalayo kanye nezindleko zokukhanda ezalandela.
4. Kwesinye isikhathi, ama-cores akhethekile angaqedwa ekubunjweni kwegobolondo. Njengoba isihlabathi sinamandla amakhulu isikhunta singahle senziwe ngendlela yokuthi izimbotshana zangaphakathi zingakhiwa ngqo ngesidingo sezinsimbi zamagobolondo.
5. Futhi, izingxenye ezincanyana kakhulu (ezifika ku-0.25 mm) zohlobo lwamakhanda amasilinda opholile emoyeni zingenziwa kalula ukubunjwa kwegobolondo ngenxa yamandla aphezulu esihlabathi asetshenziselwa ukubumba.
6. Ukuvuleka kwegobolondo kuphakeme ngakho-ke akukho ukufakwa kwegesi okwenzekayo.
7. Isamba esincane kakhulu sidinga ukusetshenziswa.
8. Ukusetshenziswa kwemishini kwenzeka kalula ngenxa yokucubungula okulula okuhilelekile ekubunjweni kwegobolondo.
Imikhawulo yeShell Mold Casting Process
1. Ama-pattens ayabiza kakhulu ngakho-ke ayonga kuphela uma esetshenziswa ekukhiqizeni okukhulu. Kuhlelo lokusebenza olujwayelekile, ukubunjwa kwegobolondo kuba ukonga ngaphezu kwesihlabathi uma umphumela odingekayo ungaphezulu kwezicucu eziyi-15000 ngenxa yezindleko zephethini eziphakeme.
2. Usayizi wokusakaza otholwe ukubunjwa kwegobolondo ulinganiselwe. Ngokuvamile, ukusikeka okunesisindo esifinyelela ku-200 kg kungenziwa, noma kungamanani amancane, kusakazwa kuze kube isisindo esingu-450 kg.
3. Izimo eziyinkimbinkimbi kakhulu azitholakali.
4. Imishini eyinkimbinkimbi iyadingeka ekuphatheni ukubunjwa kwegobolondo njengaleyo edingekayo emaphethini wensimbi ashubile.
Isikhathi Iposi: Dec-25-2020