Li-extruder tsa polasetiki ke lisebelisoa tsa mantlha indastering ea ho lokisa lipolasetiki, tse sebelisoang haholo tlhahisong ea lihlahisoa tse kang liphaephe, profiles, lifilimi, le terata le likoahelo tsa cable. Ts'ebetso ena e kenyelletsa mehato e mengata, ho kenyeletsoa ho lokisa thepa e tala, ho futhumatsa le ho qhibiliha, ho kenya polasetiki le ho ntša, ho bopa le ho pholisa, le ho lokisa-ka poso. Mohato o mong le o mong o na le tšusumetso e kholo ho boleng ba sehlahisoa sa ho qetela. Sengoliloeng sena se hlalosa ka mokhoa o hlophisehileng phallo e tloaelehileng ea ts'ebetso le lintlha tsa bohlokoa tsa tekheniki tsa extruder ea polasetiki.
1. Tokisetso ea Raw Material and Preteatment
Mohato oa pele ts'ebetsong ea extrusion ea polasetiki ke ho hlahloba le ho lokisa thepa e tala. Ho ipapisitse le litlhoko tsa sehlahisoa, lisebelisoa tse tala e ka ba resin e le 'ngoe (joalo ka polyethylene (PE) kapa polypropylene (PP)) kapa sebopeho se kopaneng sa lisebelisoa tse ngata (tse kang tse nang le li-filler tsa calcium carbonate kapa masterbatches). Lisebelisoa tse tala li tlameha ho fihlela litlhoko tse latelang:
Purity: Qoba ho silafatsoa ke litšila (joalo ka likaroloana tsa tšepe le likhechana tsa pampiri), tse ka bakang tšenyo ea thepa kapa bofokoli ba sehlahisoa.
Ho omella: Lisebelisoa tsa Hygroscopic (tse kang nylon PA le polycarbonate PC) li lokela ho omisoa ka se omisang ka 80-120℃ka lihora tse 'maloa ho thibela li-bubble nakong ea extrusion.
Mixing Uniformity: Haeba motsoako o na le li-additives, premix the masterbatch kapa li-additives tse ling ka{0}}motsoako oa lebelo le phahameng ho etsa bonnete ba ho hasana ho tšoanang.
II. Sethala sa ho fepa le ho fetisa
Lisebelisoa tse tala tse entsoeng esale pele li kena ka har'a barrel ea extruder ka hopper. Li-extruder tsa sejoale-joale li atisa ho hlomelloa ka sefepi se qobelloang kapa sefepi se sisinyehang ho netefatsa sekhahla sa phepelo se tsoelang pele le se tsitsitseng. Lintlha tsa bohlokoa nakong ena li kenyelletsa:
Feed Rate Matching: Sena se tlameha ho hokahanngoa le lebelo la screw le matla a ho qhibiliha ho qoba ho bokellana ha lintho tse bonahalang kapa ho idling ka har'a moqomo.
Anti-Moetso oa Borokho: Lerako la ka hare la hopper hangata le tepetsoa kapa le kentsoe sets'oants'o ho thibela marokho le ho thiba ka lebaka la metsi a fokolang.
III. Ho futhumatsa, ho qhibiliha, le polasetiki
Ka mor'a hore lisebelisoa tse tala li kene ka har'a barrel, butle-butle li qhibiliha 'me li entsoe ka polasetiki ka ketso e kopantsoeng ea ho potoloha ha screw le ho futhumatsa ka ntle. Ts'ebetso ena e arotsoe ka likarolo tse tharo tse sebetsang:
Karolo e fetisang (Karolo ea ho Fepa): Sekoti se potoloha ka lebelo le tlase, se sutumelletsa thepa pele. Mocheso oa moqomo o tlase (ka tloaelo 80-120 degree) ho thibela ho qhibiliha pele ho nako.
Karolo ea Compression (Karolo e qhibilihang): Mocheso oa moqomo o eketseha butle-butle ho ea holimo ho ntlha ea ho qhibiliha ea polasetiki (mohlala, hoo e ka bang 160-180℃bakeng sa PE). Botebo ba "screw groove" boa fokotseha, bo eketsa matla a ho kuta le ho fetola likaroloana tse tiileng hore e be mokelikeli oa viscous.
Karolo ea Metering (Karolo ea Homogenization): Mocheso o lula o le teng (hanyenyane ka holim'a ntlha ea ho qhibiliha), 'me sekoti se sebetsa ka lebelo le phahameng ho netefatsa khatello e tsitsitseng ea ho qhibiliha le ho hlophisoa ha junifomo.
Lintlha tsa bohlokoa tsa tekheniki: Mocheso oa mocheso oa moqomo, lebelo la screw (hangata 50-300 rpm), le khatello ea ho qhibiliha (5-20 MPa) li hloka ho lokisoa ho latela thepa ea thepa. Mohlala, ts'ebetso ea PVC e hloka mocheso o tlase (150-180 degree) ho qoba ho senyeha ha mocheso.
IV. Extrusion and Die Form
Melt e entsoeng ka polasetiki e tšeloa ka har'a "die head" ho etsa sebopeho se lakatsehang sa karolo- (joalo ka li-tubes tse chitja kapa liprofaele tse khutlonnetsepa). Die design e ama boleng ba sehlahisoa ka kotloloho mme e tlameha ho fihlela litlhoko tse latelang:
Ho leka-lekana ha channel: E netefatsa khatello e ts'oanang ka mahlakoreng 'ohle ho pholletsa le ho qhibiliha ho qoba ho tlala kapa khatello e feteletseng.
Taolo ea mocheso: Mocheso oa mocheso hangata o tlase hanyane ho feta mocheso oa barrel ho lefella ho qhala ha mocheso le ho boloka metsi.
V. Ho pholisa le ho taka
Mokelikeli o chesang oa extruded o tlameha ho pholile ka potlako le ho thehoa. Mekhoa e tloaelehileng e kenyelletsa:
Pholiso ea metsi: Sena se finyelloa ka ho qoelisoa ka tankeng ea metsi kapa tsamaiso ea ho fafatsa (joaloka mehala ea tlhahiso ea liphaephe). Mocheso oa metsi a pholileng o tlameha ho fetoloa ho latela thepa (hangata 15-40℃).
Pholiso ea moea: E loketse lifilimi tse tšesaane kapa tse tšesaane-lihlahisoa tse kamiloeng ka mabota, ho sebelisoa fene kapa lirolo tse batang ho fokotsa mocheso.
Ho sa le joalo, mochine oa ho taka o hula sehlahisoa ka lebelo le tsitsitseng ho netefatsa botsitso ba dimensional. Karo-karolelano ea lebelo la ho taka ho lebelo la extrusion (karolelano ea ho hula) e lekanya boleng ba sehlahisoa le thepa ea 'mele.
VI. Ho Seha le ho Post{1}}Ho sebetsa
Ka mor'a ho pholile, sehlahisoa se khaoloa ka likaroloana (mohlala, li-tubes tsa 6-meter) kapa se entsoe ka lirolo (mohlala, lifilimi, lithapo le likhoele) ho sebelisoa sehahi sa marang-rang. Lihlahisoa tse ling li hloka ts'ebetso e eketsehileng, joalo ka:
Phekolo ea holim'a metsi: Phekolo ea mollo kapa kalafo ea corona ho matlafatsa ho khomarela khatiso;
Tlhahlobo ea Boleng: Ho lekola botenya ba lebota ho sebelisa tekanyo ea botenya ba infrared kapa tlhahlobo ea pono bakeng sa mefokolo ea bokaholimo.
Ts'ebetso ea extrusion ea polasetiki e kopanya boiphihlelo ba li-multidisciplinary (saense ea lisebelisoa tsa polymer, boenjiniere ba mechini, le thermodynamics). Ho ntlafatsa li-parameter mothating o mong le o mong (mohlala, boemo ba mocheso le sebopeho sa screw) ho ka ntlafatsa haholo katleho ea tlhahiso le boleng ba sehlahisoa. Ka nts'etsopele ea theknoloji e bohlale ea ho etsa thepa, lisebelisoa tsa sejoale-joale tsa extrusion li kenyellelitse{4}}seseteme ea ho beha leihlo nako le ho fana ka maikutlo ka boiketsetso, ho thusa indasteri ea ho lokisa lipolasitiki hore e be{5}ka mokhoa o nepahetseng le o baballang tikoloho.
