Plastics extrusion inzira yekugadzira yakakwira-vhoriyamu umo mapurasitiki akasvibira anonyungudutswa uye anoumbwa kuita chimiro chinoenderera. Extrusion inogadzira zvinhu zvakaita sepombi/tubing, weatherstripping, fencing, deck railings, mawindow mafuremu, epurasitiki mafirimu uye sheeting, thermoplastic coatings, uye wire insulation.
Iyi nzira inotanga nekudyisa zvinhu zvepurasitiki (pellets, granules, flakes kana poda) kubva muhopi kupinda mubhodhoro re extruder. Izvo zvinhu zvinonyungudutswa zvishoma nezvishoma nemagetsi emagetsi anogadzirwa nekutendeuka screws uye nema heaters akarongwa pamwe chete nedhiramu. Iyo polima yakanyungudutswa inozomanikidzwa kuita kufa, iyo inoumba iyo polima kuita chimiro chinoomesa panguva yekutonhora.
NHOROONDO
Pombi extrusion
Yekutanga precursors kune yemazuva ano extruder yakagadzirwa mukutanga kwezana ramakore re19. Muna 1820, Thomas Hancock akagadzira "masticator" yerabha yakagadzirirwa kudzoreredza zvimedu zverabha, uye muna 1836 Edwin Chaffee akagadzira muchina unomonereka maviri wekusanganisa zvinowedzera kuita rabha. Yekutanga thermoplastic extrusion yaive muna 1935 naPaul Troester nemukadzi wake Ashley Gershoff muHamburg, Germany. Nguva pfupi yapfuura, Roberto Colombo weLMP akagadzira ekutanga mapatya screw extruders muItari.
PROCESS
Mukuwedzeredzwa kwemapurasitiki, iyo mbishi komputa zvinhu zvinowanzoitika muchimiro chenyurdles (mabhero madiki, anowanzonzi resin) ayo ane simba regiravhiti rinodyiswa kubva kumusoro wakaiswa hopper kupinda mubhodhoro re extruder. Zvinowedzerwa senge colorants uye UV inhibitors (mune chero yemvura kana pellet fomu) inowanzoshandiswa uye inogona kusanganiswa muresin isati yasvika pane hopper. Maitiro acho ane zvakawanda zvakafanana nepurasitiki jekiseni kuumbwa kubva padanho reiyo extruder tekinoroji, kunyangwe ichisiyana pakuti kazhinji inoenderera. Nepo pultrusion ichigona kupa akawanda akafanana maprofile muhurefu hunoenderera, kazhinji nekuwedzera kusimbisa, izvi zvinowanikwa nekudhonza chigadzirwa chakapedzwa kubva mukufa pane kuburitsa iyo polymer yakanyungudika kuburikidza nekufa.
Izvo zvinhu zvinopinda nepahuro yekudyisa (pakazaruka padhuze nekuseri kwembiru) uye zvinosangana ne screw. Siruuru inotenderedza (kazhinji inoshanduka eg 120 rpm) inomanikidza mabhero epurasitiki kuenda mberi mudhiramu rinopisa. Iyo inodiwa extrusion tembiricha haiwanzo kuenzana neyakaiswa tembiricha yebhari nekuda kwekudziya kwe viscous uye zvimwe zvinokonzeresa. Mune maitiro mazhinji, mbiri yekudziya inogadzirirwa dhiramu umo matatu kana anopfuura akazvimirira PID-inodzorwa heater nzvimbo zvishoma nezvishoma inowedzera tembiricha yebhari kubva kumashure (apo ipurasitiki inopinda) kumberi. Izvi zvinobvumira mabhero epurasitiki kunyunguduka zvishoma nezvishoma paanenge achisundidzirwa nemudhiramu uye kuderedza njodzi yekupisa zvakanyanya izvo zvinogona kukonzera kuparara kwepolymer.
Kuwedzera kupisa kunokonzereswa nekudzvinyirirwa kwakanyanya uye kukweshana kunoitika mukati medhiramu. Muchokwadi, kana tambo yeextrusion ichimhanyisa zvimwe zvinhu nekukurumidza zvakakwana, maheater anogona kuvharwa uye tembiricha yekunyunguduka inochengetwa nekumanikidza uye kukweshera kwega mukati medhiramu. Mumaextruder mazhinji, mafeni ekutonhodza aripo kuti achengetedze tembiricha iri pasi pemutengo wakaiswa kana kupisa kwakawanda kuchigadzirwa. Kana kutonhodzwa kwemhepo kunoratidza kusakwana saka mabhachi ekutonhodza anoiswa anoshandirwa.
Plastic extruder akachekwa nepakati kuratidza zvikamu
Kumberi kwedhiramu, purasitiki yakanyungudutswa inosiya sikuruu uye inofamba nepascreen pack kuti ibvise chero zvinosvibisa mukunyunguduka. Masikirini anosimbiswa nendiro yekupwanya (gobvu resimbi puck rine maburi akawanda akaboorwa mukati maro) sezvo kudzvanywa panguva ino kunogona kudarika 5,000 psi (34 MPa). Iyo screen pack / breaker plate musangano inoshandawo kugadzira kumashure kumanikidzwa mubhari. Kudzvinyirirwa kumashure kunodiwa kuti yunifomu inyunguduke uye kusanganisa kwakaringana kwepolymer, uye kuti kudzvanywa kwakadii kunogadzirwa kunogona "kugadziriswa" nekusiyana kwescreen pack kuumbwa (nhamba yezviratidziro, saizi yavo yewaya weave, uye mamwe maparameter). Iyi ndiro yekutyora uye skrini paki musanganiswa zvakare inobvisa "kutenderera ndangariro" yepurasitiki yakanyungudutswa uye inogadzira panzvimbo, "longitudinal memory".
Mushure mokupfuura nepakati peplateti yakanyungudutswa plastiki inopinda mufa. Iyo dhiya ndiyo inopa chigadzirwa chekupedzisira chimiro chayo uye inofanira kugadzirwa kuitira kuti purasitiki yakanyungudutswa ifambe zvakaenzana kubva pacylindrical profile, kusvika kune chigadzirwa chimiro. Kuyerera kusina kuenzana panguva ino kunogona kuburitsa chigadzirwa chine kusaririra kusingadiwe pane dzimwe nzvimbo muprofile izvo zvinogona kukonzera hondo pakutonhora. Yakasiyana-siyana maumbirwo anogona kugadzirwa, anongogumira kune anoenderera profiles.
Chigadzirwa chacho zvino chinofanira kunge chakatonhodzwa uye izvi zvinowanzowanikwa nekudhonza extrudate kuburikidza nekugeza kwemvura. Plastiki yakanaka kwazvo thermal insulators uye saka inonetsa kutonhora nekukurumidza. Kuenzaniswa nesimbi, plastiki inoitisa kupisa kwayo kure kakapetwa ka2,000 zvishoma nezvishoma. Muchubhu kana pombi extrusion line, bhavhu remvura rakavharwa rinoitwa nechokutsvaira chakanyatsodzorwa kuchengetedza chichangobva kuumbwa uye chichiri chakanyunguduka chubhu kana pombi kuti isadonha. Kune zvigadzirwa zvakaita sepurasitiki sheeting, kutonhora kunowanikwa nekukwevera kuburikidza neseti yekutonhora rolls. Kune mafirimu uye akaonda kwazvo sheeting, kutonhora kwemhepo kunogona kushanda sekutanga kutonhora nhanho, sepamhepo firimu extrusion.
Plastic extruder zvakare inoshandiswa zvakanyanya kudzoreredza tsvina yepurasitiki yakadzokororwa kana zvimwe zvinhu mbishi mushure mekuchenesa, kuronga uye / kana kusanganisa. Ichi chinhu chinowanzo kuwedzererwa kuita mafilaments akakodzera kuchekwa mubead kana pellet stock kuti ishandiswe seanotangira pakuenderera mberi nekugadzirisa.
SCREW DESIGN
Pane shanu dzinokwanisika nzvimbo mune thermoplastic screw. Sezvo terminology isina kumira muindasitiri, mazita akasiyana anogona kureva nzvimbo idzi. Mhando dzakasiyana dzepolymer dzichava neakasiyana screw dhizaini, mamwe asingasanganisi ese anokwanisika nzvimbo.
A simple plastic extrusion screw
Extruder screws Kubva kuBoston Matthews
Mazhinji screws ane aya mazoni matatu:
● Feed zone (inonziwo solids conveying zone): nzvimbo iyi inodyisa resin muextruder, uye kudzika kwechaneli kunowanzofanana munzvimbo yese.
● Melting zone (inonziwo shanduko kana compression zone): yakawanda yepolymer inonyungudutswa muchikamu chino, uye kudzika kwechiteshi kunowedzera kudiki zvishoma.
● Metering zone (inonziwo melt conveying zone): nzvimbo iyi inonyungudutsa zvikamu zvekupedzisira uye zvinosanganiswa kusvika kune imwe tembiricha uye kuumbwa. Kufanana nenzvimbo yekudyisa, kudzika kwechiteshi kunongogara munzvimbo yese iyi.
Mukuwedzera, mhepo inoputika (matanho maviri) screw ine:
● Decompression zone. Munharaunda iyi, zvingangoita zvikamu zviviri muzvitatu pasi pe screw, chiteshi chinoerekana chadzika, icho chinobvisa kudzvanywa uye chinobvumira chero magasi akavharirwa (unyoro, mweya, zvinonyungudutsa, kana reactants) kuti abudiswe kunze ne vacuum.
● Chikamu chechipiri chemita. Iyi zoni yakafanana neyekutanga metering zone, asi nehukuru hukuru hwechiteshi. Inoshanda kudzoreredza kunyungudika kuti iwane kuburikidza nekupokana kwezviratidziro uye kufa.
Kazhinji screw kureba kunongedzerwa dhayamita yayo seL: D reshiyo. Semuyenzaniso, siruuru ye6-inch (150 mm) dhayamita pa24:1 ichaita 144 inches (12 ft) kureba, uye pa32:1 ikareba 192 inches (16 ft) kureba. Chiyero cheL:D che25:1 chinowanikwa, asi mimwe michina inokwira kusvika pa40:1 yekuwedzera kusanganisa uye kubuda kwakawanda pairi screw diameter. Matanho maviri (vented) screws anowanzo 36: 1 kuverengera iwo maviri ekuwedzera nzvimbo.
Imwe neimwe nzvimbo ine imwe kana anopfuura thermocouples kana maRTD mudhiramu madziro ekudzora tembiricha. Iyo "tembiricha mbiri" kureva, tembiricha yenzvimbo imwe neimwe yakakosha kumhando uye maitiro ekupedzisira extrudate.
TYPICAL EXTRUSION MATERIALS
HDPE pombi panguva extrusion. Iyo HDPE zvinhu zviri kuuya kubva kune hita, kupinda mufa, zvino kupinda mutangi inotonhorera. Iyi pombi yeAcu-Power conduit yakabatanidzwa - yakasviba mukati nejaketi reorenji rakatetepa, kuratidza tambo dzemagetsi.
Typical epurasitiki zvinhu kuti anoshandiswa extrusion zvinosanganisira asi kwete chete: polyethylene (PE), polypropylene, acetal, acrylic, naironi (polyamides), polystyrene, polyvinyl chloride (PVC), acrylonitrile butadiene styrene (ABS) uye polycarbonate.[4] ]
KUFA MATYPES
Kune dzakasiyana-siyana dzinofa dzinoshandiswa mumapurasitiki extrusion. Kunyangwe paine mutsauko wakakura pakati pemhando dzekufa uye kuoma, zvese zvinofa zvinobvumidza kuenderera mberi kwepolymer kunyungudika, kusiyana nekusaenderera mberi kwekugadzirisa senge jekiseni molding.
Yakaputika firimu extrusion
Blow extrusion yepurasitiki firimu
Kugadzirwa kwefirimu repurasitiki kune zvigadzirwa zvakadai semabhegi ekutenga uye kuenderera mberi sheeting kunowanikwa uchishandisa mutsara wefirimu wakaputika.
Iyi nzira yakafanana neyenguva dzose extrusion process kusvika pakufa. Kune marudzi matatu makuru ekufa anoshandiswa mukuita uku: annular (kana crosshead), spider, uye spiral. Annular dies ndiyo yakapfava, uye vimba nepolymer inonyunguduka inotenderedza iyo yese yemuchinjikwa chikamu chefa isati yabuda mufa; izvi zvinogona kukonzera kuyerera kusina kuenzana. Mhungu inofa inoumbwa nepakati mandrel yakasungirirwa kune yekunze die ring kuburikidza nenhamba ye "makumbo"; nepo kuyerera kwakanyanya symmetric pane mu annular dies, akati wandei weld mitsara inogadzirwa iyo inonetesa firimu. Spiral inofa inobvisa nyaya ye weld lines uye asymmetrical kuyerera, asi zvakanyanya kuoma.
Iyo yakanyungudutswa inotonhodzwa zvishoma isati yasiya mufi kuti ibudise isina simba semi-solid chubhu. Iyi dhayamita yechubhu inokwidziridzwa nekukurumidza kuburikidza nemhepo, uye chubhu inokwevera kumusoro nema roller, ichitambanudza purasitiki mune zvese zvakachinjika uye dhizaini nzira. Kudhirowa uye kuvhuvhuta kunoita kuti firimu riite nhete kupfuura chubhu yakawedzera, uye zvakare inokwenenzvera iyo polymer molecular cheni munzira inoona yakanyanya kuomarara epurasitiki. Kana iyo firimu ikakweverwa kupfuura yainopeperetswa (yekupedzisira chubhu dhayamita iri padyo nedhayamita yakawedzera) mamorekuru epolymer achanyatso kuenderana negwara rekudhirowa, kuita firimu rine simba munzira iyoyo, asi isina kusimba munzira inochinjika. . Firimu rine dhayamita rakakura zvakakura kupfuura dhayamita yakadhindwa richava nesimba rakawanda munzira inochinjika, asi shoma mugwara rekudhirowa.
Kana iri polyethylene uye mamwe semi-crystalline polymers, sezvo firimu rinotonhorera rinopenya pane inozivikanwa sechando mutsetse. Sezvo firimu richiramba richitonhora, rinokweverwa kuburikidza nemaseti akati wandei e nip rollers kuti riite flat-flat tubing, iyo inogona kubva yanyungudutswa kana kupatsanurwa kuita maviri kana anopfuura rolls emapepa.
Sheet/firimu extrusion
Sheet/film extrusion inoshandiswa kuburitsa mapepa epurasitiki kana mafirimu akakora zvakanyanya kuti asafuridzirwa. Kune marudzi maviri ekufa anoshandiswa: T-shaped uye jasi hanger. Chinangwa cheidzi chinofa ndechekudzoreredza uye kutungamira kuyerera kwepolymer kunyunguduka kubva kune imwechete yakatenderera inobuda kubva kune extruder kune yakatetepa, flat planar kuyerera. Mumarudzi ese ari maviri anofa anovimbisa kugara, yunifomu inoyerera ichipfuura nepakati pese chikamu chechikamu chefa. Kutonhodza kunowanzo kudhonzwa nepakati peseti yekutonhodza rolls (calender kana "chill" rolls). Mune sheet extrusion, aya ma rolls haangounze kutonhora kunodiwa chete asiwo anoongorora ukobvu hwemashizha uye magadzirirwo epamusoro.[7] Kazhinji co-extrusion inoshandiswa kuisa imwe kana akawanda layer pamusoro pechigadziko kuti uwane chaiwo zvimiro zvakaita seUV-absorption, magadzirirwo, oxygen permeation kuramba, kana simba rekuratidzira.
A common post-extrusion process yeplastic sheet stock is thermoforming, apo bepa rinodziiswa kusvika rakapfava (plastiki), uye rinoumbwa neforoma kuita chimiro chitsva. Kana vacuum ichishandiswa, izvi zvinowanzotsanangurwa sekuti vacuum kugadzira. Maonero (kureva kugona/ kuwanda kwebepa kuti rikweverwe kune mold inogona kusiyana pakadzika kubva pa 1 kusvika 36 inches kazhinji) yakakosha uye inokanganisa zvakanyanya kuumba nguva dzekutenderera kwemapurasitiki mazhinji.
Tubing extrusion
Yakawedzerwa tubing, senge mapaipi ePVC, anogadzirwa achishandisa mafiro akafanana seanoshandiswa mukuputirwa firimu extrusion. Positive pressure inogona kuiswa kumakomba emukati kuburikidza nepini, kana kudzvanya kwakashata kunogona kuiswa kune dhayamita yekunze uchishandisa vacuum sizer kuve nechokwadi chekupedzisira zviyero. Mamwe lumens kana maburi anogona kuunzwa nekuwedzera akakodzera emukati mandrels kune iyo kufa.
A Boston Matthews Medical Extrusion Line
Multi-layer tubing applications zvakare inogara iripo mukati meindasitiri yemotokari, pombi dzemvura & kudziyisa indasitiri uye indasitiri yekurongedza.
Pamusoro pejaketi extrusion
Pamusoro pejaketi extrusion inobvumira kushandiswa kwekunze kwepurasitiki pawaya iripo kana tambo. Iyi ndiyo nzira yakajairika yekuisa insulating waya.
Kune marudzi maviri akasiyana emidziyo yekufa inoshandiswa kupfekedza pamusoro pewaya, tubing (kana jekete) uye kumanikidza. Mukushandisa jekete, iyo polymer inonyungudika haibati waya yemukati kusvika pakarepo pamberi pemiromo inofa. Mukudzvanyirira tooling, iyo melt inobata waya yemukati nguva refu isati yasvika pamuromo unofa; izvi zvinoitwa pakudzvinyirirwa kwepamusoro kuve nechokwadi chekunamatira kwakanaka kwekunyungudika. Kana kushamwaridzana kwepedyo kana kunamatira kunodiwa pakati pechitsva chitsva newaya iripo, kushandiswa kwekumanikidza kunoshandiswa. Kana kunamatira kusingadiwi / kudikanwa, jekete tooling inoshandiswa panzvimbo.
Coextrusion
Coextrusion ndiyo extrusion yezvikamu zvakawanda zvezvinhu panguva imwe chete. Iyi mhando yeextrusion inoshandisa maextruder maviri kana anopfuura kunyunguduka uye kuendesa yakadzikama volumetric throughput yemapurasitiki akasiyana e viscous kune imwechete extrusion musoro (kufa) iyo inoburitsa zvinhu muchimiro chaunoda. Iyi tekinoroji inoshandiswa pane chero maitiro anotsanangurwa pamusoro (yakavhuvhuta firimu, overjacketing, tubing, sheet). Ukobvu hwehuputi hunodzorwa nekumhanya uye saizi yemunhu anoburitsa zvinhu.
5 : 5 Layer co-extrusion ye cosmetic "kusvina" chubhu
Mune akawanda-chaiwo epasirese mamiriro, imwechete polymer haigone kuita zvese zvinodiwa zvekushandisa. Compound extrusion inobvumira zvinhu zvakasanganiswa kuti zviburitswe, asi coextrusion inochengeta zvinhu zvakaparadzana sezvikamu zvakasiyana muchigadzirwa chakawedzerwa, zvichibvumira kuiswa kwakakodzera kwezvinhu zvine zvinhu zvakasiyana senge oxygen permeability, simba, kuomarara, uye kupfeka kuramba.
Extrusion coating
Extrusion coating iri kushandisa inopeperetswa kana kukanda firimu process kupfekedza imwe layer pane iripo rollstock yebepa, foil kana firimu. Semuenzaniso, iyi nzira inogona kushandiswa kuvandudza hunhu hwebepa nekuiputira nepolyethylene kuti iite kuti isapinda mumvura. Iyo extruded layer inogona zvakare kushandiswa seanonamira kuunza zvimwe zviviri zvinhu pamwechete. Tetrapak muenzaniso wekutengesa weiyi maitiro.
COMPOUND EXTRUSIONS
Compounding extrusion inzira inosanganisa imwe kana akawanda mapolymer ane additives kuti ape epurasitiki makomisheni. Zvokudya zvinogona kunge zviri mapellet, hupfu uye / kana zvinwiwa, asi chigadzirwa chinowanzo kuve mupellet fomu, kuti chishandiswe mune mamwe mapurasitiki-ekugadzira maitiro senge extrusion uye jekiseni molding. Sezvinoita zvechinyakare extrusion, kune huwandu hwakasiyana muhukuru hwemuchina zvinoenderana nekushandisa uye kudiwa kwemukati. Nepo ingave imwe- kana kaviri-screw extruder inogona kushandiswa mune yechinyakare extrusion, iko kudikanwa kwekuringana musanganiswa mukusanganisa extrusion kunoita mapatya-screw extruder zvese asi zvinosungirwa.
MATYPES EEXTRUDER
Kune maviri madiki-emhando dzemapatya screw extruder: kutenderera-kutenderera uye kupokana-kutenderera. Iyi nomenclature inoreva hukama hwehukama hwese screw spins ichienzaniswa neimwe. Mune co-rotation modhi, ese arikurukuru anotenderedzwa newachi kana pakaunda zvichienderana newachi; mukupokana-kutenderera, sikuruu imwe inotenderera newachi nepo imwe ichitenderedza pakaunda newachi. Zvave zvichiratidzwa kuti, kune yakapihwa muchinjiko wechikamu nharaunda uye dhigirii rekupindirana (intermeshing), axial velocity uye dhigirii rekusanganisa yakakwira mune co-inotenderera mapatya extruders. Nekudaro, kumanikidza kuvaka kwakakwira mune inopokana-inotenderera extruder. Iyo screw dhizaini inowanzoita modular mukuti akasiyana ekutakura uye kusanganisa zvinhu zvakarongerwa pamashafts kubvumira kukurumidza kugadziridzwa kwekuchinja kwemaitiro kana kutsiviwa kwechimwe chinhu nekuda kwekupfeka kana kukuvara kwekuora. Saizi yemuchina inotangira padiki se12 mm kusvika pahombe se380mm
ZVAKANAKA
Kubatsira kukuru kweextrusion ndeyekuti maprofiles akadai semapombi anogona kuitwa chero kureba. Kana zvinhu zvacho zvichinyatsochinjika, mapaipi anogona kugadzirwa akareba kana kukoira pareel. Imwe mukana ndeye extrusion yemapombi ane akasanganiswa coupler kusanganisira rubber chisimbiso.
Nguva yekutumira: Feb-25-2022
