Ukubunjwa kwegobolondokuyinqubo lapho isihlabathi esixutshwe ne-thermosetting resin sivunyelwa ukuthi sihlangane nepuleti lephethini yensimbi eshisayo, ukuze kwakheke igobolondo lesikhunta elincanyana neliqinile elizungeze i-pattem. Khona-ke igobolondo liyasuswa ephethini futhi i-cope kanye ne-drag ikhishwa ndawonye futhi igcinwe ku-flask enezinto ezidingekayo zokusekela futhi insimbi encibilikisiwe ithululelwa esikhunjeni.
Ngokuvamile, isihlabathi esomile nesicolekile (90 kuya ku-140 GFN) esingenalo ubumba ngokuphelele sisetshenziselwa ukulungisa isihlabathi sokubumba igobolondo. Ubukhulu bokusanhlamvu okufanele bukhethwe buncike ekuqedeni okungaphezulu okufiswayo ekubunjweni. Usayizi wokusanhlamvu omuhle kakhulu udinga inani elikhulu le-resin, okwenza isikhunta sibize.
Ama-synthetic resins asetshenziswa ekubumbeni igobolondo empeleni ama-thermosetting resins, aba lukhuni ngokungenakulungiseka ngenxa yokushisa. Ama-resin asetshenziswa kakhulu ama-phenol formaldehyde resins. Kuhlanganiswe nesihlabathi, banamandla aphezulu kakhulu nokumelana nokushisa. Ama-phenolic resins asetshenziswa ekubumbeni igobolondo ngokuvamile awohlobo lwezigaba ezimbili, okungukuthi, inhlaka ine-phenol eyeqile futhi isebenza njengempahla ye-thermoplastic. Ngesikhathi sokumbozwa ngesihlabathi i-resin ihlanganiswa ne-catalyst efana ne-hexa methylene tetramine (hexa) ngengxenye engaba ngu-14 kuya ku-16% ukuze kuthuthukiswe izici ze-thermosetting. Izinga lokushisa lokuphulukisa lalokhu lingaba ngu-150 C kanti isikhathi esidingekayo singaba amasekhondi angu-50 kuya kwangu-60.
Izinzuzo ze-Shell Mold Casting Process
1.Ukubunjwa kwegobolondongokuvamile anembe kakhulu kunokwakheka kwesihlabathi. Kungenzeka ukuthola ukubekezelelana kwe-+0.25 mm ye-castings yensimbi kanye ne-+0. 35 mm we-grey cast iron castings kanyei-ductile iron castingsngaphansi kwezimo ezijwayelekile zokusebenza. Endabeni yesikhunta segobolondo esibekezeleleka eduze, umuntu angasithola kububanzi obusuka ku-+0.03 ukuya ku-+0.13 mm ngezinhlelo ezithile zokusebenza.
2. Indawo ebushelelezi ingatholakala ekubunjweni kwamagobolondo. Lokhu kutholakala ngokuyinhloko ngosayizi omncane wokusanhlamvu osetshenzisiwe. Ibanga elijwayelekile lobumahhadlahhadla liku-oda lama-microns angu-3 ukuya kwangu-6.
3. Ama-engeli asalungiswa, aphansi kune- ukukhishwa kwesihlabathi, ziyadingeka ekubunjweni kwegobolondo. Ukwehliswa kwama-engeli asalungiswa kungase kube kusuka ku-50 kuya ku-75%, okusindisa kakhulu izindleko zempahla kanye nezindleko zomshini ezilandelayo.
4. Ngezinye izikhathi, ama-cores akhethekile angase akhishwe ekubunjweni kwegobolondo. Njengoba isihlabathi sinamandla amakhulu isikhunta singaklanywa ngendlela yokuthi izimbobo zangaphakathi zingakheka ngokuqondile ngesidingo sezinhlamvu zegobolondo.
5. Futhi, izingxenye ezincane kakhulu (kufika ku-0.25 mm) zohlobo lwamakhanda e-cylinder apholile emoyeni angenziwa kalula ngokubumba igobolondo ngenxa yamandla aphezulu esihlabathi asetshenziselwa ukubumba.
6. Ukungena kwegobolondo kuphezulu ngakho-ke akukho ukufakwa kwegesi okwenzekayo.
7. Isihlabathi esincane kakhulu esidinga ukusetshenziswa.
8. Umshini ungenzeka kalula ngenxa yokucubungula okulula okuhilelekile ekubumbeni igobolondo.
Imikhawulo Yenqubo Yokusakaza I-Shell Mold
1. Amaphethini abiza kakhulu ngakho ayonga kuphela uma esetshenziswa ekukhiqizeni okukhulu. Kuhlelo lokusebenza olujwayelekile, ukubumba igobolondo kuba ukonga phezu kokubumba kwesihlabathi uma okukhiphayo okudingekayo kungaphezu kwezingcezu eziyi-15000 ngenxa yezindleko zephethini ephakeme.
2. Ubukhulu bokubunjwa obutholakala ngokubunjwa kwegobolondo bunqunyelwe. Ngokuvamile, ukulingwa okunesisindo esifinyelela ku-200 kg kungenziwa, nakuba ngenani elincane, ukubunjwa okufika esisindweni sama-450 kg kwenziwa.
3. Izimo eziyinkimbinkimbi kakhulu azikwazi ukutholakala.
4. Kudingeka imishini eyinkimbinkimbi kakhulu yokuphatha amagobolondo afana nalawo adingekayo kumaphethini ensimbi ashisayo.
Isikhathi sokuthumela: Dec-25-2020