E ngotsoe ke Andy oa fektheri ea Baiyear
E ntlafalitsoe ka la 5 Pulungoana 2022
1. Sekhahla sa ho fokotseha
Sebopeho le lipalo tsa thermoplastic molding shrinkage Joalokaha ho boletsoe ka holimo, lintlha tse amang shrinkage ea thermoplastic molding ke tse latelang:
1.1 Mefuta ea polasetiki Nakong ea ho bōptjoa ha thermoplastics, ka lebaka la phetoho ea molumo e bakoang ke crystallization, khatello e matla ea ka hare, khatello e kholo ea masala e leqhoa karolong ea polasetiki, le mokhoa o matla oa limolek'hule, sekhahla sa shrinkage se phahame ho feta sa polasetiki ea thermosetting.Ntle le moo, shrinkage ka mor'a ho bopeha, ho honyela ka mor'a kalafo ea annealing kapa mongobo hangata e kholo ho feta ea polasetiki ea thermosetting.
1.2 Litšobotsi tsa likarolo tsa polasetiki Ha thepa e qhibilihisitsoeng e kopana le bokaholimo ba sekoti, lera le ka ntle lea fola hang-hang ho etsa khetla e tiileng e tlase.Ka lebaka la ho se sebetse hantle ha mocheso oa polasetiki, karolo e ka hare ea karolo ea polasetiki e pholile butle-butle ho etsa lera le tiileng le nang le shrinkage e kholo.Ka hona, botenya ba lerako, ho pholile butle, le botenya bo phahameng ba sekhahla bo tla fokotseha haholo.Ho phaella moo, ho ba teng kapa ho se be teng ha ho kenya le ho hlophisoa le bongata ba ho kenya ka ho toba ho ama tataiso ea phallo ea thepa, ho aroloa ha sekhahla le ho hanyetsa ho fokotseha, kahoo litšoaneleho tsa likarolo tsa polasetiki li na le tšusumetso e kholo ho boholo le tataiso ea shrinkage.
1.3 Lintlha tse kang sebopeho, boholo le kabo ea phallo ea phepelo e ama ka kotloloho tataiso ea phallo ea thepa, kabo ea letsoalo, phepelo ea ho ts'oara khatello le nako ea ho bopa.Boema-kepe ba ho fepa ka ho toba le boema-kepe ba ho fepa bo nang le likarolo tse kholo (haholo-holo tse teteaneng) li na le ho fokotseha ho honyenyane empa tsela e kholo, 'me boema-kepe ba ho fepa ka bophara le bo bokhutšoane bo na le tataiso e nyane.Haufi le koung ea phepelo kapa e bapileng le tataiso ea phallo ea thepa, shrinkage e kholo.
1.4 Maemo a ho bōptjoa Mocheso oa hlobo o phahame, thepa e entsoeng ka ho qhibiliha e pholile butle-butle, ho teteana ho phahame, 'me ho fokotseha ho hoholo, haholo-holo bakeng sa lisebelisoa tsa kristale, ho fokotseha ho hoholo ka lebaka la kristale e phahameng le phetoho e kholo ea molumo.Kabo ea mocheso oa hlobo e boetse e amana le pholileng ea ka hare le ea ka ntle le ho lumellana ha sekhahla sa karolo ea polasetiki, e amang ka ho toba
E ama boholo le tataiso ea shrinkage ea karolo ka 'ngoe.Ho phaella moo, khatello ea ho ts'oara le nako le eona e na le tšusumetso e kholo holim'a ho fokotseha, ho fokotseha ho nyane empa tataiso e kholo ha khatello e phahame 'me nako e telele.Khatello ea ente e phahame, phapang ea viscosity ea thepa e qhibilihisitsoeng e nyane, khatello ea "interlayer shear" e nyane, 'me rebound ea elastic ka mor'a ho heletsoa e kholo, kahoo shrinkage e ka fokotsoa ka nepo, mocheso oa thepa o phahame, shrinkage e kholo. , empa tataiso e nyenyane.Ka hona, ho lokisa mocheso oa hlobo, khatello, lebelo la ente le nako ea ho pholile le lintlha tse ling nakong ea ho bopa le tsona li ka fetola ka nepo ho fokotseha ha karolo ea polasetiki.
Ha ho etsoa hlobo, ho ea ka mefuta e fapaneng ea shrinkage ea lipolasetiki tse fapaneng, botenya ba lebota le sebopeho sa karolo ea polasetiki, sebopeho, boholo le kabo ea koung ea phepelo, sekhahla sa shrinkage sa karolo ka 'ngoe ea karolo ea polasetiki e khethoa ke boiphihlelo, ebe boholo ba cavity bo baloa.Bakeng sa likarolo tsa polasetiki tse nepahetseng haholo le ha ho le thata ho tseba sekhahla sa shrinkage, mekhoa e latelang e lokela ho sebelisoa ho rala hlobo:
① Nka sekhahla se senyenyane sa shrinkage bakeng sa bophara ba bokantle ba likarolo tsa polasetiki, le sekhahla se seholo sa shrinkage bakeng sa bophara bo ka hare, e le hore u siee sebaka sa khalemelo kamora teko ea hlobo.
②Teko ea hlobo e etsa qeto ea sebopeho, boholo le maemo a ho bopa a sistimi ea gating.
③ Likarolo tsa polasetiki tse lokelang ho sebetsoa ka mor'a hore li sebetsoe ka morao ho fumana hore na ho na le phetoho e kae (tekanyo e tlameha ho etsoa kamora lihora tse 24 kamora ho theoa).
④ Lokisa hlobo ho latela shrinkage ea 'nete.
⑤ Leka hape hlobo 'me u fetole maemo a ts'ebetso ho fetola hanyenyane boleng ba shrinkage ho finyella litlhoko tsa likarolo tsa polasetiki.
2. Mokelikeli
2.1 The fluidity ea thermoplastics ka kakaretso e ka hlahlojoa ho tloha letotong la li-indices tse kang boima ba molek'hule, melt index, Archimedes spiral flow length, viscosity e hlakileng le karolelano ea phallo (bolelele ba ts'ebetso / botenya ba lerako la polasetiki).Boima ba limolek'hule tse nyane, kabo e pharalletseng ea boima ba limolek'hule, ho se tloaelehe ha sebopeho sa limolek'hule, index e phahameng ea ho qhibiliha, bolelele ba phallo e telele ea spiral, viscosity e tlase e bonahalang, le tekanyo e kholo ea phallo, metsi a teng hantle.ka ho bopeng ente.Ho ea ka litlhoko tsa moralo oa hlobo, metsi a polasetiki a sebelisoang hangata a ka aroloa ka mekhahlelo e meraro:
①Mokelikeli o motle oa PA, PE, PS, PP, CA, poly(4) methyl pentylene;
②Polystyrene series resin (e kang ABS, AS), PMMA, POM, polyphenylene ether e nang le metsi a mahareng;
③ PC e sa sebetseng hantle, PVC e thata, polyphenylene ether, polysulfone, polyarylsulfone, fluoroplastic.
2.2 Mokelikeli oa lipolasetiki tse fapaneng le ona oa fetoha ka lebaka la lintlha tse fapaneng tsa ho bopa.Lintlha tse ka sehloohong tse susumetsang ke tse latelang:
① Ha mocheso o phahame, o phahamisa metsi a lintho tse bonahalang, empa li-plastiki tse fapaneng le tsona li fapane, PS (haholo-holo e hananang le tšusumetso le boleng bo phahameng ba MFR), PP, PA, PMMA, polystyrene e fetotsoeng (e kang ABS, AS) , PC, CA le lisebelisoa tse ling tsa polasetiki li fapana haholo ka mocheso.Bakeng sa PE, POM, ho eketseha ha mocheso kapa ho fokotseha ho na le phello e fokolang ho metsi a eona.Ka hona, ea pele e lokela ho fetola mocheso ho laola metsi nakong ea ho bōptjoa.
②Ha khatello ea ente e eketseha, thepa e entsoeng ka ho qhibilihisoa e tla beoa haholo, 'me metsi a tla boela a eketsehe, haholo-holo PE le POM li na le maikutlo a mangata, kahoo khatello ea ente e lokela ho fetoloa ho laola metsi nakong ea ho bōptjoa.
③Sebopeho, boholo, sebopeho, moralo oa sistimi e pholileng, ho hanyetsa ho phalla ha lintho tse entsoeng ka ho qhibilihisoa (joalo ka bokaholimo ba bokaholimo, botenya ba karolo ea pele, sebopeho sa sekoti, sistimi ea mosi) le lintlha tse ling li ama ka kotloloho ho phalla ha lintho tse entsoeng ka sekoting.Mokelikeli oa sebele ka hare ho naha, haeba mocheso oa thepa e qhibilihisitsoeng o theoha 'me ho hanyetsa metsi ho eketseha, ho phalla ho tla fokotseha.Ha ho etsoa hlobo, mohaho o utloahalang o lokela ho khethoa ho ea ka mokelikeli oa polasetiki o sebelisitsoeng.Nakong ea ho bōptjoa, mocheso oa thepa, mocheso oa hlobo, khatello ea ente, lebelo la ente le lintlha tse ling le tsona li ka laoloa ho lokisa hantle boemo ba ho tlatsa ho finyella litlhoko tsa ho bōpa.
3. Crystallinity
Thermoplastics e ka aroloa ka mekhahlelo e 'meli: polasetiki ea crystalline le li-non-crystalline (tse tsejoang hape e le amorphous) ho latela ho ba sieo ha tsona ha kristale nakong ea condensation.
Ntho e bitsoang "crystallization phenomenon" ke hore ha polasetiki e fetoha ho tloha sebakeng se entsoeng ka ho qhibilihisoa ho ea ho condensation, limolek'hule li tsamaea ka bolokolohi, ka ho feletseng li le boemong bo sa tsitsang, 'me limolek'hule li khaotsa ho tsamaea ka bolokolohi, ho ea ka boemo bo tsitsitseng hanyenyane,' me ho na le tšekamelo. ho etsa hore tlhophiso ya molecular e be mohlala o tlwaelehileng.ketsahalo.
E le tekanyetso ea ho ahlola ponahalo ea mefuta ena e 'meli ea polasetiki, e itšetlehile ka ho pepeseha ha likarolo tsa polasetiki tse marako a teteaneng.Ka kakaretso, lisebelisoa tsa crystalline li na le opaque kapa translucent (joaloka POM, joalo-joalo), le lisebelisoa tsa amorphous li na le pepeneneng (joalo ka PMMA, joalo-joalo).Empa ho na le mekhelo, joalo ka poly (4) methyl pentylene ke polasetiki ea kristale empa e na le pepenene e phahameng, ABS ke thepa ea amorphous empa e sa bonahale.
Ha o rala hlobo le ho khetha mochini oa ho bopa ente, litlhoko tse latelang le litemoso tsa lipolasetiki tsa kristale li lokela ho hlokomeloa:
①Mocheso o hlokahalang hore mocheso oa thepa o nyolohele mochesong oa ho bōptjoa o moholo, 'me lisebelisoa tse nang le matla a maholo a polasetiki li lokela ho sebelisoa.
②Mocheso o tsoang nakong ea pholileng o moholo, kahoo o lokela ho pholile ka ho feletseng.
③ Phapang e khethehileng ea matla a khoheli pakeng tsa boemo bo qhibilihisitsoeng le boemo bo tiileng bo boholo, shrinkage ea ho bopa e kholo, 'me masoba le masoba a atisa ho etsahala.
④Ho pholile ka potlako, khanya e tlase ea kristale, ho honyela ho honyane le pepeneneng e phahameng.Crystallinity e amana le botenya ba lerako la karolo ea polasetiki, botenya ba lebota bo lieha ho pholile, kristale e phahame, shrinkage e kholo, 'me thepa ea' mele e ntle.Ka hona, thepa ea kristale e lokela ho laola mocheso oa hlobo ha ho hlokahala.
⑤ Anisotropy ea bohlokoa le khatello e kholo ea ka hare.Ka mor'a ho senya, limolek'hule tse sa tsitsang li atisa ho tsoela pele ho khanya 'me li boemong ba ho se leka-lekane ha matla, e leng ntho e atisang ho fetoha le ho ba le ntoa.
⑥ Mocheso oa mocheso oa crystallization o moqotetsane, 'me ho bonolo ho kenya lintho tse sa qhibilihang ka har'a hlobo kapa ho thibela koung ea lijo.
4. Li-plastiki tse sa utloeng mocheso le li-hydrolyzed habonolo
4.1 Thermal sensibility e bolela hore li-plastiki tse ling li na le mocheso o matla haholoanyane, 'me nako ea ho futhumatsa e telele ka mocheso o phahameng kapa karolo ea sefapano sa koung ea phepelo e nyane haholo,' me ha ketso ea ho kuta e le khōlō, mocheso oa thepa oa eketseha 'me o tloaelehile. ho feto-fetoha ha 'mala, ho senyeha, le ho senyeha.E na le tšobotsi ena.lipolasetiki li bitsoa lipolasetiki tse sa utloeng mocheso.Tse kang PVC e thata, polyvinylidene chloride, vinyl acetate copolymer, POM, polychlorotrifluoroethylene, joalo-joalo Ha lipolasetiki tse sa utloeng mocheso li senyeha, lihlahisoa tse kang monomers, likhase le lintho tse tiileng li hlahisoa, haholo-holo likhase tse bolileng lia halefisa, li chesa kapa li chefo. 'meleng oa motho, lisebelisoa le hlobo.Ka hona, tlhokomelo e lokela ho lefshoa ho moralo oa hlobo, khetho ea mochini oa ho bopa ente le ho bopa.Mechini ea ho etsa ente ea screw e lokela ho khethoa.Karolo e ka holimo ea tsamaiso ea liheke e lokela ho ba kholo.Hlobo le barrel li lokela ho ba le chrome-plated, 'me ha hoa lokela ho ba le likhutlo.Eketsa stabilizer ho fokolisa thepa ea eona e thibelang mocheso.
4.2 Esita le haeba li-plastiki tse ling (tse kang PC) li na le metsi a fokolang, li tla bola tlas'a mocheso o phahameng le khatello e phahameng.Thepa ena e bitsoa bonolo hydrolysis, e lokelang ho futhumatsoa le ho omisoa esale pele.
5. Khatello ea kelello cracking le qhibiliha fracture
5.1 Li-plastiki tse ling li na le bothata ba ho imeloa kelellong, 'me li na le khatello ea kelello ea ka hare nakong ea ho bōptjoa' me li brittle ebile li bonolo ho phunyeha.Likarolo tsa polasetiki li tla phunyeha tlas'a ketso ea matla a ka ntle kapa solvent.Ho finyella sena, ntle le ho eketsa li-additives ho lisebelisoa tse tala ho ntlafatsa ho hanyetsa mapheo, tlhokomelo e lokela ho lefshoa ho omisa lihlahisoa tse tala, 'me maemo a ho bōpa a lokela ho khethoa ka mokhoa o utloahalang ho fokotsa khatello ea ka hare le ho eketsa ho hanyetsa ho phatloha.Sebopeho se loketseng sa likarolo tsa polasetiki se lokela ho khethoa, 'me mehato e kang ho kenya ha ea lokela ho behoa ho fokotsa khatello ea kelello.Ha ho etsoa hlobo, moepa oa ho senya o lokela ho eketseha, 'me ho lokela ho khethoa sebaka se loketseng sa ho fepa le mochine oa ejection.Nakong ea ho bōptjoa, mocheso oa thepa, mocheso oa hlobo, khatello ea ente le nako ea ho pholisa li lokela ho lokisoa hantle ho qoba ho senya ha likarolo tsa polasetiki li bata haholo ebile li brittle., Ka mor'a ho bōptjoa, likarolo tsa polasetiki li boetse li lokela ho phekoloa ka morao ho ntlafatsa ho hanyetsa mapheo, ho felisa khatello ea kelello ea ka hare le ho thibela ho kopana le li-solvents.
5.2 Ha polymer e qhibiliha ka sekhahla se itseng sa ho qhibiliha ha metsi e feta ka lesoba la nozzle ka mocheso o sa khaotseng 'me sekhahla sa phallo ea eona se feta boleng bo itseng, mapetsong a hlakileng a pota-potileng holim'a metsi a qhibilihang a bitsoa fracture ea qhibiliha, e tla senya ponahalo le thepa ea' mele. likarolo tsa polasetiki.Ka hona, ha u khetha li-polymers tse nang le sekhahla se phahameng sa ho qhibiliha, joalo-joalo, karolo ea sefapano sa nozzle, semathi le boema-kepe ba phepelo e lokela ho eketseha, lebelo la ente le lokela ho fokotsoa, 'me mocheso oa thepa o eketsehe.
6. Ts'ebetso ea mocheso le sekhahla sa ho pholisa
6.1 Li-plastiki tse fapa-fapaneng li na le thepa e fapaneng ea mocheso e kang mocheso o khethehileng, mocheso oa mocheso le mocheso oa mocheso oa mocheso.Ha polasetiki e na le mocheso o phahameng o khethehileng, ho hlokahala mocheso o mongata, 'me mochine oa ho etsa ente o nang le matla a mangata a polasetiki o lokela ho khethoa.Nako ea ho pholisa ea polasetiki e nang le mocheso o phahameng oa mocheso oa mocheso e ka ba khutšoanyane 'me ho senya ho sa le pele, empa ho senyeha ha pholileng ho lokela ho thibeloa ka mor'a ho senya.Lipolasetiki tse nang le mocheso o fokolang oa mocheso li na le lebelo le fokolang la ho pholile (joaloka li-polymers tsa ionic, joalo-joalo), kahoo li tlameha ho pholile ka ho feletseng, 'me phello ea pholileng ea hlobo e tlameha ho matlafatsoa.Li-mold tsa semathi tse chesang li loketse li-plastiki tse nang le mocheso o tlaase o khethehileng le mocheso o phahameng oa mocheso.Lipolasetiki tse nang le mocheso o moholo o khethehileng, mocheso o tlaase oa mocheso, mocheso o fokolang oa mocheso le sekhahla sa ho pholisa butle ha li khone ho bōpa ka lebelo le phahameng, 'me ho lokela ho khethoa mechine e loketseng ea ho bōpa ente le ho pholile ha hlobo ho tlameha ho matlafatsoa.
6.2 Lipolasetiki tse fapaneng lia hlokahala ho boloka sekhahla se nepahetseng sa ho pholisa ho latela mefuta le litšobotsi tsa tsona le sebopeho sa likarolo tsa polasetiki.Ka hona, hlobo e tlameha ho behoa ka mokhoa oa ho futhumatsa le o pholileng ho ea ka litlhoko tsa ho bōpa ho boloka mocheso o itseng oa hlobo.Ha mocheso oa thepa o eketsa mocheso oa hlobo, o lokela ho pholile ho thibela likarolo tsa polasetiki hore li se ke tsa senyeha ka mor'a ho senya, ho khutsufatsa potoloho ea ho bōpa, le ho fokotsa kristale.Ha mocheso oa litšila oa polasetiki o sa lekana ho boloka hlobo ka mocheso o itseng, hlobo e lokela ho ba le lisebelisoa tsa ho futhumatsa ho boloka hlobo ka mocheso o itseng ho laola sekhahla sa ho pholile, ho netefatsa hore metsi a pholile, ho ntlafatsa maemo a ho tlatsa kapa ho laola polasetiki. dikarolo ho phola butle.Thibela ho tsidifala ho sa lekaneng ka hare le ka ntle ho dikarolo tsa polasetiki tse teteaneng le ho ntlafatsa botshepehi.Bakeng sa ba nang le mokelikeli o motle, sebaka se seholo sa ho bopa le mocheso o sa lekaneng oa thepa, ho ea ka maemo a ho bōptjoa ha likarolo tsa polasetiki, ho futhumatsa kapa ho pholisa ka linako tse ling ho sebelisoa ka tsela e fapaneng kapa ho futhumatsa le ho futhumatsa sebakeng seo ho sebelisoa hammoho.Bakeng sa morero ona, hlobo e lokela ho hlomelloa ka mokhoa o ts'oanang oa ho futhumatsa kapa oa ho futhumatsa.
Nako ea poso: Nov-29-2022
