Kujambula mozungulira(BrEkuumba) imaphatikizapo nkhungu yotentha yomwe imadzazidwa ndi chiwongolero kapena kulemera kwa zinthu.Kenako imazunguliridwa pang'onopang'ono (nthawi zambiri imazungulira nkhwangwa ziwiri za perpendicular) zomwe zimapangitsa kuti zinthu zofewa zibalalike ndikumamatira kumakoma a nkhungu.Pofuna kusunga makulidwe amtundu wonsewo, nkhunguyo imapitilirabe kusinthasintha nthawi zonse pakutentha komanso kupewa kugwa kapena kupindika komanso panthawi yozizira.Njirayi inkagwiritsidwa ntchito ku mapulasitiki m'zaka za m'ma 1940 koma m'zaka zoyambirira sizinagwiritsidwe ntchito pang'onopang'ono chifukwa zinali zochepetsetsa zomwe zimangokhala ndi mapulasitiki ochepa.M'zaka makumi awiri zapitazi, kusintha kwa kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe ka kayendetsedwe kakenibubone kadwe kanu kangawunikire
Rotocasting (yomwe imadziwikanso kuti rotacasting), poyerekeza, imagwiritsa ntchito ma resin odzichiritsa okha mu nkhungu yosatenthedwa, koma imagawana liwiro lozungulira pang'onopang'ono lofanana ndi kuumba mozungulira.Spincasting siyenera kusokonezedwa ndi, kugwiritsa ntchito utomoni wodzichiritsa nokha kapena zitsulo zoyera pamakina othamanga kwambiri a centrifugal.
Mbiri
Mu 1855 R. Peters wa ku Britain analemba ntchito yoyamba ya biaxial rotation ndi kutentha.Njira yozungulira iyi idagwiritsidwa ntchito popanga zipolopolo zazitsulo ndi zida zina zopanda kanthu.Cholinga chachikulu chogwiritsira ntchito kuumba mozungulira chinali kupanga kusasinthasintha mu makulidwe a khoma ndi kachulukidwe.Mu 1905 ku United States FA Voelke anagwiritsa ntchito njira imeneyi pobowola zinthu za sera.Izi zinapangitsa kuti a GS Baker ndi GW Perks apange mazira a chokoleti opanda kanthu mu 1910. Kuumba mozungulira kunayambanso ndipo RJ Powell anagwiritsa ntchito njirayi popanga pulasitala ku Paris m'ma 1920s.Njira zoyambira izi pogwiritsa ntchito zida zosiyanasiyana zidawongolera kupita patsogolo kwa njira yozungulira yomwe imagwiritsidwa ntchito masiku ano ndi mapulasitiki.
Pulasitiki idayambitsidwa munjira yozungulira yozungulira koyambirira kwa zaka za m'ma 1950.Chimodzi mwa ntchito zoyamba chinali kupanga mitu ya zidole.Makinawa adapangidwa ndi makina a E Blue box-oven, owuziridwa ndi axle yakumbuyo ya General Motors, yoyendetsedwa ndi mota yamagetsi yakunja ndikuwotchedwa ndi zoyatsira gasi zokwera pansi.Chikombolecho chinapangidwa ndi electroformed nickel-copper, ndipo pulasitiki inali PVC plastisol yamadzimadzi.Njira yozizirira inali kuyika nkhungu m'madzi ozizira.Njira yozungulira iyi idapangitsa kuti pakhale zidole zina zapulasitiki.Pamene kufunikira ndi kutchuka kwa njirayi kuchulukirachulukira, idagwiritsidwa ntchito popanga zinthu zina monga ma cones amsewu, ma buoys am'madzi, ndi malo opumirako magalimoto.Kutchuka kumeneku kunapangitsa kuti pakhale makina akuluakulu.Njira yatsopano yowotchera idapangidwanso, kuchokera ku ma jets oyambilira a gasi kupita ku makina apamlengalenga othamanga kwambiri.Ku Europe m'zaka za m'ma 1960 njira ya Engel idapangidwa.Izi zidapangitsa kuti ziwiya zazikulu zopanda kanthu zipangidwe mu polyethylene yotsika kwambiri.Njira yozizirira inali yozimitsa zoyatsira ndi kulola pulasitiki kuumitsa uku akugwedezekabe mu nkhungu.[2]
Mu 1976, Association of Rotational Moulders (ARM) idakhazikitsidwa ku Chicago ngati bungwe lazamalonda padziko lonse lapansi.Cholinga chachikulu cha mgwirizanowu ndikuwonjezera chidziwitso cha teknoloji yozungulira yozungulira ndi ndondomeko.
M’zaka za m’ma 1980, mapulasitiki atsopano, monga polycarbonate, poliyesitala, ndi nayiloni, anayambitsidwa kuumba mozungulira.Izi zadzetsa kugwiritsiridwa ntchito kwatsopano kwa njirayi, monga kupanga matanki amafuta ndi makina opangira mafakitale.Kafukufuku yemwe wachitika kuyambira chakumapeto kwa zaka za m'ma 1980 ku Queen's University Belfast wapangitsa kuti pakhale kuwunika kolondola komanso kuwongolera njira zoziziritsa kutengera kukulitsa kwawo "Rotolog system".
Zida ndi zida
Makina ozungulira ozungulira amapangidwa mosiyanasiyana.Nthawi zambiri zimakhala ndi nkhungu, uvuni, chipinda chozizirirapo, ndi zopota za nkhungu.Zopota zimayikidwa pazitsulo zozungulira, zomwe zimapereka chophimba chofanana cha pulasitiki mkati mwa nkhungu iliyonse.
Nkhungu (kapena zida) zimapangidwa kuchokera ku chitsulo chowotcherera kapena chitsulo.Njira yopangira zinthu nthawi zambiri imayendetsedwa ndi kukula kwa gawo ndi zovuta;zinthu zovuta kwambiri zimakhala zopangidwa ndi zida zotayira.Nthawi zambiri nkhungu zimapangidwa kuchokera ku chitsulo chosapanga dzimbiri kapena aluminiyamu.Zoumba za aluminiyamu nthawi zambiri zimakhala zokhuthala kwambiri kuposa chitsulo chofanana ndi chitsulo, chifukwa ndi chitsulo chofewa.Kukhuthala kumeneku sikumakhudza nthawi yozungulira kwambiri chifukwa matenthedwe a aluminiyamu amakhala ochulukirapo kuposa chitsulo.Chifukwa chofuna kupanga chitsanzo chisanayambe kuponyedwa, nkhungu zoponyedwa zimakhala ndi ndalama zowonjezera zomwe zimagwirizanitsidwa ndi kupanga zida, pamene zitsulo zopangidwa ndi zitsulo kapena aluminiyamu, makamaka zikagwiritsidwa ntchito pazinthu zochepa, zimakhala zotsika mtengo.Komabe, nkhungu zina zimakhala ndi aluminiyamu ndi chitsulo.Izi zimalola makulidwe osinthika m'makoma a mankhwalawa.Ngakhale kuti njirayi siili yofanana ndi kuumba jekeseni, imapatsa wopanga njira zambiri.Kuphatikizika kwa aluminiyumu ku chitsulo kumapereka mphamvu yowonjezera kutentha, kuchititsa kuti kusungunuka kwamadzi kumakhalabe mumadzimadzi kwa nthawi yaitali.
Nthawi yotumiza: Aug-04-2020