Rotational Moulding(BrEmolding) suav nrog cov pwm uas muaj cua sov uas tau ntim nrog cov nqi lossis cov khoom hnyav ntawm cov khoom.Nws yog ces maj mam tig (feem ntau nyob ib ncig ntawm ob lub perpendicular axes) ua rau cov khoom softened disperse thiab lo rau ntawm phab ntsa ntawm cov pwm.Txhawm rau kom tswj tau qhov tuab ntawm txhua qhov, cov pwm txuas ntxiv tig txhua lub sijhawm thaum lub sijhawm cua sov thiab kom tsis txhob sagging lossis deformation kuj thaum lub caij txias.Cov txheej txheem tau siv rau cov yas hauv xyoo 1940s tab sis thaum ntxov xyoo tsis tau siv tsawg vim tias nws yog cov txheej txheem qeeb txwv rau cov yas me me.Ob xyoo dhau los, kev txhim kho ntawm cov txheej txheem tswj thiab kev txhim kho nrog cov hmoov yas tau ua rau muaj kev siv ntau ntxiv.
Rotocasting (tseem hu ua rotacasting), los ntawm kev sib piv, siv nws tus kheej-kho resins nyob rau hauv ib tug unheated pwm, tab sis qhia qeeb rotational speeds nyob rau hauv ntau nrog rotational molding.Spincasting yuav tsum tsis txhob tsis meej pem nrog ib qho, siv nws tus kheej-kho resins lossis hlau dawb hauv lub tshuab centrifugal siab ceev.
Keeb kwm
Xyoo 1855 R. Peters ntawm Tebchaws Askiv tau sau tseg thawj zaug kev siv biaxial tig thiab cua sov.Txoj kev sib hloov molding no tau siv los tsim cov hlau phom loj thiab lwm cov hlab ntsha hollow.Lub hom phiaj tseem ceeb ntawm kev siv rotational molding yog los tsim kom muaj qhov sib xws ntawm phab ntsa thickness thiab ntom.Xyoo 1905 hauv Tebchaws Meskas FA Voelke tau siv txoj kev no rau qhov hollowing ntawm cov khoom siv quav ciab.Qhov no ua rau GS Baker's thiab GW Perks cov txheej txheem ntawm kev ua hollow chocolate qe nyob rau hauv 1910. Rotational molding tsim ntxiv thiab RJ Powell siv cov txheej txheem no rau molding plaster ntawm Paris nyob rau hauv 1920s.Cov txheej txheem thaum ntxov no siv cov ntaub ntawv sib txawv qhia txog kev nce qib hauv txoj kev sib hloov molding niaj hnub no nrog cov yas.
Plastics tau qhia rau cov txheej txheem kev sib hloov molding nyob rau hauv thaum ntxov 1950s.Ib qho ntawm thawj daim ntawv thov yog los tsim cov menyuam roj hmab taub hau.Cov tshuab tau ua los ntawm E Blue lub thawv-qhov cub tshuab, tau txais kev tshoov siab los ntawm General Motors rear qag, siv los ntawm lub tshuab hluav taws xob sab nraud thiab cua sov los ntawm cov pa taws hauv pem teb.Cov pwm yog tsim los ntawm electroformed npib tsib xee-tooj liab, thiab cov yas yog cov kua PVC plastisol.Txoj kev ua kom txias yog muab cov pwm tso rau hauv dej txias.Cov txheej txheem ntawm kev sib hloov molding no coj mus rau kev tsim lwm yam khoom ua si yas.Raws li kev thov thiab kev nyiam ntawm cov txheej txheem no tau nce, nws tau siv los tsim lwm yam khoom xws li txoj kev cones, marine buoys, thiab tsheb armrests.Qhov kev muaj koob meej no tau coj mus rau kev tsim cov tshuab loj.Ib qho tshiab ntawm cov cua sov kuj tau tsim, mus los ntawm thawj lub dav hlau ncaj qha roj mus rau qhov tam sim no indirect high velocity air system.Hauv Tebchaws Europe thaum xyoo 1960s cov txheej txheem Engel tau tsim.Qhov no tau tso cai rau kev tsim cov thawv loj loj los tsim hauv cov khoom siv polyethylene tsawg.Txoj kev ua kom txias yog los ntawm kev kaw lub qhov cub thiab cia cov yas kom tawv thaum tseem pob zeb hauv pwm.[2]
Xyoo 1976, Lub Koom Haum ntawm Kev Sib Hloov Moulders (ARM) tau pib hauv Chicago ua lub koom haum kev lag luam thoob ntiaj teb.Lub hom phiaj tseem ceeb ntawm lub koom haum no yog kom muaj kev paub txog kev sib hloov molding tshuab thiab txheej txheem.
Xyoo 1980s, cov yas tshiab, xws li polycarbonate, polyester, thiab nylon, tau qhia rau kev sib hloov molding.Qhov no tau ua rau kev siv tshiab rau cov txheej txheem no, xws li kev tsim cov roj tso tsheb hlau luam thiab cov moldings muaj.Cov kev tshawb fawb uas tau ua tiav txij li xyoo 1980s ntawm Queen's University Belfast tau ua rau kev txhim kho ntau dua kev saib xyuas thiab tswj cov txheej txheem txias raws li lawv txoj kev loj hlob ntawm "Rotolog system".
Khoom siv thiab cuab yeej
Rotational molding tshuab yog tsim nyob rau hauv ntau qhov ntau thiab tsawg.Lawv feem ntau muaj pwm, qhov cub, chav txias, thiab pwm spindles.Cov spindles yog mounted ntawm ib tug rotating axis, uas muab ib tug uniform txheej ntawm cov yas nyob rau hauv txhua pwm.
Moulds (los yog tooling) yog tsim los ntawm welded sheet hlau los yog cam khwb cia.Txoj kev fabrication feem ntau yog tsav los ntawm ib feem loj thiab complexity;feem ntau intricate qhov chaw yuav ua los ntawm cam khwb cia tooling.Pwm feem ntau yog tsim los ntawm stainless hlau lossis txhuas.Aluminium pwm feem ntau yog tuab dua li cov pwm sib npaug, vim nws yog cov hlau softer.Qhov tuab no tsis cuam tshuam rau lub voj voog lub sijhawm tseem ceeb vim tias txhuas lub thermal conductivity yog ntau zaus ntau dua li cov hlau.Vim yog qhov yuav tsum tau tsim cov qauv ua ntej casting, cam khwb cia pwm yuav muaj cov nqi ntxiv nrog rau kev tsim cov cuab yeej, whereas fabricated steel los yog aluminium pwm, tshwj xeeb tshaj yog thaum siv rau qhov nyuaj, tsis tshua muaj nqi.Txawm li cas los xij, qee cov pwm muaj ob qho txhuas thiab hlau.Qhov no tso cai rau qhov sib txawv thicknesses nyob rau hauv cov phab ntsa ntawm cov khoom.Thaum cov txheej txheem no tsis yog qhov tseeb raws li kev txhaj tshuaj molding, nws muab cov qauv tsim nrog ntau txoj kev xaiv.Lub aluminium ntxiv rau cov hlau muab lub peev xwm kub ntau dua, ua rau cov dej ntws mus nyob rau hauv cov kua dej rau lub sijhawm ntev.
Post lub sij hawm: Aug-04-2020