NaAndy anobva kuBaiyear fekitori
Yakadzorerwa November 5, 2022
1. Shrinkage rate
Chimiro uye kuverenga kwe thermoplastic molding shrinkage Sezvataurwa pamusoro apa, izvo zvinokanganisa thermoplastic molding shrinkage ndezvizvi:
1.1 Mhando dzePlastiki Panguva yekuumbwa kwe thermoplastics, nekuda kwekushanduka kwevhoriyamu kunokonzerwa nekristalllization, kushushikana kwakasimba kwemukati, kushushikana kukuru kwakasara kwakaomeswa nechando muchikamu chepurasitiki, uye yakasimba mamolecular orientation, shrinkage rate yakakwira kupfuura iyo thermosetting mapurasitiki.Pamusoro pezvo, iyo shrinkage mushure mekuumbwa, iyo shrinkage mushure mekuvhara kana humidity conditioning kurapwa kazhinji yakakura kupfuura iyo thermosetting mapurasitiki.
1.2 Hunhu hwezvikamu zvepurasitiki Kana zvinhu zvakanyungudutswa zvasangana nepamusoro pegomba, denga rekunze rinobva ratonhora kuita goko rakasimba.Nekuda kwehurombo hwekupisa kwepurasitiki, chikamu chemukati chechikamu chepurasitiki chinotonhodzwa zvishoma nezvishoma kuti chiite dhizaini yakasimba yakasimba ine shrinkage yakakura.Naizvozvo, ukobvu hwemadziro, kutonhora kunononoka, uye yakakwirira density layer ukobvu huchadzikira zvakanyanya.Pamusoro pezvo, kuvapo kana kusavapo kwekuisa uye kurongeka uye kuwanda kwekuisa kunokanganisa zvakananga kutungamira kwekuyerera kwezvinhu, density kugovera uye shrinkage kuramba, saka hunhu hwezvikamu zvepurasitiki zvine simba guru pakukura uye kutungamira kwe shrinkage.
1.3 Zvinhu zvakaita sechimiro, saizi uye kugovera kweyekupinza yekudya zvinokanganisa zvakananga kutungamira kwekuyerera kwezvinhu, kugovera density, kudzvinyirirwa-inobata kudya uye nguva yekuumba.Chiteshi chekudyisa chakananga uye chiteshi chekudya chine hombe-chikamu (kunyanya chakakora muchinjiko-chikamu) chine diki shrinkage asi yakakura nzira, uye yakafara uye pfupi chiteshi chekudyisa chine diki nzira.Pedyo nechiteshi chekudya kana kuenderana negwara rekuyerera kwezvinhu, iyo shrinkage yakakura.
1.4 Mamiriro ekugadzira Mold tembiricha yakakwira, iyo yakanyungudutswa inotonhora zvishoma nezvishoma, density yakakwira, uye shrinkage yakakura, kunyanya kune crystalline zvinhu, iyo shrinkage yakakura nekuda kweiyo yakakwira crystallinity uye vhoriyamu yakakura shanduko.Iyo mold tembiricha yekugovera inoenderana zvakare nemukati uye kunze kutonhora uye density kufanana kwechikamu chepurasitiki, icho chinobata zvakananga
Inobata hukuru uye kutungamira kwekuderera kwechikamu chimwe nechimwe.Pamusoro pezvo, kudzvanywa kwekubata uye nguva zvakare zvine simba guru pachibvumirano, chibvumirano chidiki asi kutungamira kwakakura kana kudzvanywa kwakakwira uye nguva yakareba.Kudzvanywa kwejekiseni kwakakwira, mutsauko weviscosity wezvinhu zvakanyungudutswa idiki, iyo interlayer shear stress idiki, uye elastic rebound mushure mekudhirowa yakakura, saka shrinkage inogona kudzikiswa zvakakodzera, tembiricha yemidziyo yakakwira, shrinkage yakakura. , asi nhungamiro idiki.Naizvozvo, kugadzirisa tembiricha yekuumbwa, kudzvanywa, kumhanya kwejekiseni uye nguva yekutonhora uye zvimwe zvinhu panguva yekuumbwa zvinogona zvakare kushandura zvakakodzera shrinkage yechikamu chepurasitiki.
Paunenge uchigadzira mold, maererano ne shrinkage yemhando dzakasiyana-siyana dzepurasitiki, kukora kwemadziro uye chimiro chechikamu chepurasitiki, chimiro, saizi uye kugoverwa kwechiteshi chekudyisa, shrinkage rate yechikamu chimwe nechimwe chechikamu chepurasitiki inotsanangurwa neruzivo, uye ipapo saizi yegomba inoverengerwa.Kune yakakwirira-chaiyo zvikamu zvepurasitiki uye kana zvakaoma kubata shrinkage rate, nzira dzinotevera dzinofanira kushandiswa kugadzira mold:
① Tora iyo diki shrinkage mwero weiyo dhayamita yekunze yezvikamu zvepurasitiki, uye yakakura shrinkage mwero weiyo dhayamita yemukati, kuti usiye nzvimbo yekururamisa mushure mekuyedzwa kwekuumbwa.
②Muedzo we mold unosarudza fomu, saizi uye mamiriro ekuumba eiyo gating system.
③ Zvikamu zvepurasitiki zvinofanirwa kugadzirwa mushure-zvinogadziriswa kuti zvitarise shanduko yedimensional (chiyero chinofanira kuitwa mushure memaawa makumi maviri nemana mushure mekudhirowa).
④ Gadzirisa mold zvinoenderana neiyo chaiyo shrinkage.
⑤ Edza zvakare mold uye shandura maitiro ekugadzirisa zvishoma kugadzirisa kukosha kwe shrinkage kuti isangane nezvinodiwa zvezvikamu zvepurasitiki.
2. Liquidity
2.1 The fluidity ye thermoplastics inogona kuwanzo kuongororwa kubva kune dzakatevedzana dze indices senge molecular weight, melt index, Archimedes spiral flow length, inooneka viscosity uye kuyerera ratio (process kureba / epurasitiki madziro ukobvu).Diki molecular huremu, yakafara molecular uremu kugovera, kushomeka kwema molecular chimiro chenguva dzose, yakakwira melt index, kureba kutenderera kuyerera kureba, kuderera kunooneka viscosity, uye hombe yekuyerera ratio, iyo fluidity yakanaka.mukuumba jekiseni.Zvinoenderana nezvinodiwa zvekugadzira mold, iyo fluidity yemapurasitiki anowanzo shandiswa anogona kukamurwa kuita zvikamu zvitatu:
①Good fluidity PA, PE, PS, PP, CA, poly(4) methyl pentylene;
②Polystyrene series resin (yakadai seABS, AS), PMMA, POM, polyphenylene ether ine fluidity yepakati;
③Yakashata fluidity PC, yakaoma PVC, polyphenylene ether, polysulfone, polyarylsulfone, fluoroplastic.
2.2 The fluidity yemapurasitiki akasiyana zvakare inoshanduka nekuda kweakasiyana ekuumba zvinhu.Zvikuru zvinofurira zvinhu ndezvizvi:
① Kukwirisa tembiricha, kunowedzera kuyerera kwezvinhu, asi mapurasitiki akasiyana zvakare akasiyana, PS (kunyanya kusapindirana uye yakakwira MFR kukosha), PP, PA, PMMA, yakagadziridzwa polystyrene (yakadai seABS, AS) , PC, CA uye mamwe mapurasitiki fluidity inosiyana zvakanyanya nekushisa.Kune PE, POM, kuwedzera tembiricha kana kudzikira hakuna mhedzisiro yekuyerera kwayo.Naizvozvo, iyo yekutanga inofanirwa kugadzirisa tembiricha kudzora fluidity panguva yekuumbwa.
②Kana kudzvanywa kwejekiseni kunowedzera, zvinhu zvakanyungudutswa zvichaveurwa zvakanyanya, uye kunyungudika kuchawedzerawo, kunyanya PE nePOM zvinonyanya kunzwisiswa, saka iyo jekiseni yekumanikidza inofanirwa kugadziridzwa kudzora fluidity panguva yekuumbwa.
③Iyo fomu, saizi, marongero, dhizaini yekutonhodza, kuyerera kwekupokana kwezvinhu zvakanyungudutswa (zvakadai sekupera kwepamusoro, ukobvu hwechikamu chepamberi, chimiro chemhango, exhaust system) nezvimwe zvinhu zvinokanganisa kuyerera kwezvinhu zvakanyungudutswa mugomba.Iyo chaiyo fluidity mukati memukati, kana tembiricha yezvinhu zvakanyungudutswa yakadzikiswa uye kushomeka kwemvura kunowedzera, iyo fluidity inoderera.Paunenge uchigadzira mold, chimiro chinonzwisisika chinofanira kusarudzwa maererano nekuyerera kwepurasitiki inoshandiswa.Munguva yekuumbwa, tembiricha yemidziyo, tembiricha yekuumbwa, kudzvanywa kwejekiseni, kumhanya kwejekiseni uye zvimwe zvinhu zvinogona zvakare kudzorwa kuti igadzirise zvakanaka mamiriro ekuzadza kuti asangane nezvinodiwa zvekuumba.
3. Crystallinity
Thermoplastics inogona kupatsanurwa muzvikamu zviviri: mapurasitiki ecrystalline uye asiri-crystalline (anozivikanwawo seamorphous) mapurasitiki maererano nekusavapo kwavo kwekristallisation panguva yekuomeswa.
Iyo inonzi crystallization phenomenon ndeyokuti kana plastiki inoshanduka kubva kune yakanyungudutswa kusvika kune condensation, mamorekuru anofamba akazvimiririra, zvachose mumamiriro asina kugadzikana, uye mamorekuru anomira kufamba akasununguka, maererano nechinzvimbo chakanyatsogadziriswa, uye pane tsika. kuita kuti hurongwa hwema molecular ive muenzaniso wakajairika.chiitiko.
Semuyero wekutonga kutaridzika kweaya marudzi maviri emapurasitiki, zvinoenderana nekubuda pachena kwenzvimbo dzakakora-madziro epurasitiki epurasitiki.Kazhinji, makristasi emidziyo ane opaque kana translucent (senge POM, nezvimwewo), uye amorphous zvinhu zviri pachena (senge PMMA, nezvimwewo).Asi pane zvisizvo, zvakaita sepoly (4) methyl pentylene ipurasitiki ine crystalline asi ine kujeka kwepamusoro, ABS ndeye amorphous zvinhu asi isiri pachena.
Paunenge uchigadzira mold uye kusarudza jekiseni rekuumba muchina, zvinotevera zvinodiwa uye zvekuchengetedza zvekristaro mapurasitiki zvinofanirwa kucherechedzwa:
①Kupisa kunodiwa kuti tembiricha yemidziyo ikwire kusvika kune tembiricha yekuumbwa yakakura, uye midziyo ine yakakura plasticizing simba inofanirwa kushandiswa.
②Kupisa kunoburitswa panguva yekutonhodza kwakakura, saka kunofanira kunyatsotonhodzwa.
③ Iyo chaiyo giravhiti mutsauko pakati peyakanyungudutswa uye yakasimba mamiriro akakura, iyo yekuumba shrinkage yakakura, uye shrinkage maburi uye pores zvinowanzoitika.
④Kukurumidza kutonhora, kuderera kwekristaro, kuderera kudiki uye kujeka kwakanyanya.Iyo crystallinity ine hukama nemadziro emadziro echikamu chepurasitiki, ukobvu hwemadziro hunononoka kutonhora, iyo crystallinity yakakwirira, shrinkage yakakura, uye zvimiro zvemuviri zvakanaka.Naizvozvo, iyo crystalline zvinhu zvinofanirwa kudzora tembiricha yekuumbwa sezvinodiwa.
⑤ Yakakosha anisotropy uye kushushikana kukuru kwemukati.Mushure mekudhirowa, iwo mamorekuru asina kurongeka anowanzo kuenderera mberi nekupenya uye ari mumamiriro ekusaenzana kwesimba, izvo zvinokonzeresa deformation uye warpage.
⑥ Iyo tembiricha yekristaro yakatetepa, uye zviri nyore kupinza zvinhu zvisina kunyungudika muforoma kana kuvhara chiteshi chekudyisa.
4. Mapurasitiki anopisa uye mapurasitiki ari nyore hydrolyzed
4.1 Thermal senitivity inoreva kuti mamwe mapurasitiki anonyanya kunzwa kupisa, uye nguva yekudziya yakareba pakupisa kwepamusoro kana chikamu chepakati chechiteshi chekudyisa chakanyanya kudiki, uye kana kuita kwekuveura kwakakura, tembiricha yemidziyo inowedzera uye inowanzoitika. kushanduka ruvara, kudzikisirwa, uye kuora.Hune hunhu uhu.mapurasitiki anonzi mapurasitiki anonzwa kupisa.Zvakadai sePVC yakaoma, polyvinylidene chloride, vinyl acetate copolymer, POM, polychlorotrifluoroethylene, nezvimwewo. Kana mapurasitiki asinganzwiri kupisa akaora, ne-zvigadzirwa zvakadai semamonomeri, magasi, uye zvimedu zvinogadzirwa, kunyanya mamwe magasi akaora anogumbura, anopisa kana kuti ane chepfu. kumuviri wemunhu, midziyo uye zviumbwa.Naizvozvo, kutarisisa kunofanirwa kubhadharwa kune mold dhizaini, kusarudzwa kwemajekiseni ekuumba michina uye kuumba.Screw injection molding machines inofanira kusarudzwa.Muchinjikwa-chikamu chegating system inofanira kunge yakakura.Iyo mold uye dhiramu inofanira kunge yakapfava chrome, uye hapafanirwe kuve nemakona.Wedzera stabilizer kuderedza kupisa-sensitive properties.
4.2 Kunyange kana mamwe mapurasitiki (akadai sePC) aine mvura shoma, anoora pasi pekupisa kwakanyanya uye kudzvanywa kwakanyanya.Iyi pfuma inonzi nyore hydrolysis, iyo inofanirwa kupiswa uye kuomeswa pamberi.
5. Kushungurudzika kuputika uye kunyunguduka kuputsika
5.1 Mamwe mapurasitiki anonzwa kushushikana, uye anowanzo kushushikana kwemukati panguva yekuumbwa uye ane brittle uye ari nyore kutsemuka.Zvikamu zvepurasitiki zvichaputika pasi pekuita kwesimba rekunze kana solvent.Kuti izvi zviitike, kunze kwekuwedzera kuwedzera kune zvigadzirwa zvekuvandudza kuputika kwekuputika, kutarisa kunofanira kubhadharwa pakuomeswa kwezvinhu zvakasvibirira, uye mamiriro ekuumba anofanirwa kusarudzwa zvinonzwisisika kuti kuderedze kushushikana kwemukati uye kuwedzera kupikisa kwekuputika.Chimiro chinonzwisisika chezvikamu zvepurasitiki chinofanira kusarudzwa, uye zviyero zvakaita sekuisa hazvifanirwe kuisirwa kuderedza kushushikana.Paunenge uchigadzira mold, iyo yekudzikisa slope inofanirwa kuwedzerwa, uye inonzwisisika yekudyisa chiteshi uye ejection mechanism inofanira kusarudzwa.Munguva yekuumbwa, tembiricha yemidziyo, tembiricha yekuumbwa, kudzvanywa kwejekiseni uye nguva yekutonhora inofanirwa kugadziridzwa zvakanaka kudzivirira kudhirikirwa kana zvikamu zvepurasitiki zvanyanya kutonhora uye brittle., Mushure mekuumbwa, zvikamu zvepurasitiki zvinofanirawo kugadziriswa mushure mekugadzirisa kuputika, kubvisa kushushikana kwemukati uye kurambidza kusangana nemishonga.
5.2 Kana iyo polymer yakanyunguduka neimwe yekunyungudika kuyerera ichipfuura nepaburi remuromo patembiricha yenguva dzose uye kuyerera kwayo kuchipfuura imwe kukosha, kuputika kuri pachena kwakachinjika panzvimbo yakanyunguduka kunonzi kunyunguduka kunyungudika, izvo zvinokuvadza chitarisiko uye zvimiro zvemuviri. zvikamu zvepurasitiki.Naizvozvo, kana uchisarudza mapolymer ane yakanyanya kunyungudika kuyerera mwero, nezvimwe, iyo muchinjiko-chikamu chemhino, mumhanyi, uye chiteshi chekudya chinofanirwa kuwedzerwa, kumhanya kwejekiseni kunofanirwa kuderedzwa, uye tembiricha yemidziyo inofanira kuwedzerwa.
6. Thermal performance uye kutonhora chiyero
6.1 Mapurasitiki akasiyana-siyana ane zvakasiyana-siyana zvekupisa zvakadai sekupisa kwakananga, kupisa kwekushisa uye kupisa kwekushisa.Kana plasticizing ine yakanyanya kupisa kupisa, huwandu hukuru hwekupisa hunodiwa, uye jekiseni rekugadzira muchina rine yakakura plasticizing simba rinofanira kusarudzwa.Iyo nguva yekutonhora yepurasitiki ine yakanyanya kupisa kupisa tembiricha inogona kupfupika uye kudhirowa kwave kutanga, asi kutonhora kunofanirwa kudziviswa mushure mekudhirowa.Mapurasitiki ane low thermal conductivity ane kutonhora kunonoka (senge ionic polymers, nezvimwewo), saka inofanira kunge yakanyatsotonhorera, uye kutonhora kwe mold kunofanira kusimbiswa.Hot mumhanyi molds akakodzera mapurasitiki ane yakaderera chaiyo kupisa uye yakakwirira yekupisa conductivity.Mapurastiki ane hombe chaiyo kupisa, yakaderera yekupisa conductivity, yakaderera thermal deformation tembiricha uye inononoka kutonhora mwero haikodzeri kune yakakwirira-kukasira kuumbwa, uye yakakodzera jekiseni rekuumba michina inofanirwa kusarudzwa uye kutonhora kwe mold kunofanirwa kusimbiswa.
6.2 Mapurasitiki akasiyana anodiwa kuchengetedza mwero wakakodzera wekutonhora zvinoenderana nemhando dzawo uye maitiro uye chimiro chezvikamu zvepurasitiki.Naizvozvo, mold inofanirwa kuiswa neinodziya uye inotonhorera system zvinoenderana nezvinodiwa zvekuumba kuchengetedza imwe tembiricha yekuumbwa.Kana tembiricha yechinhu ichiwedzera tembiricha yekuumbwa, inofanirwa kunyoroveswa kudzivirira zvikamu zvepurasitiki kubva pakuremara mushure mekudhonzwa, kupfupisa kutenderera kutenderera, uye kuderedza crystallinity.Kana kupisa kwepurasitiki kusingakwani kuchengetedza mold pane imwe tembiricha, mold inofanirwa kunge yakashongedzerwa neinodziya system kuchengetedza mold pane imwe tembiricha kudzora kutonhora, kuve nechokwadi chekuyerera, kunatsiridza kuzadza kana kudzora mapurasitiki. zvikamu kuti zvitonhore zvishoma nezvishoma.Dzivirira kutonhora kusina kuenzana mukati nekunze kwezvikamu zvepurasitiki zvakakora nemadziro uye kunatsiridza kujeka.Kune avo vane mvura yakanaka, nzvimbo yakakura yekuumba uye tembiricha isina kuenzana, zvinoenderana nemamiriro ekuumba ezvikamu zvepurasitiki, kupisa kana kutonhora dzimwe nguva kunoshandiswa zvakasiyana kana kupisa kwenzvimbo uye kutonhora kunoshandiswa pamwechete.Nechinangwa ichi, mold inofanirwa kuve yakashongedzerwa neinodziya inotonhorera kana yekudziya system.
Nguva yekutumira: Nov-29-2022
