I-Plastics extrusion iyinqubo yokukhiqiza ivolumu ephezulu lapho ipulasitiki eluhlaza incibilikiswa khona bese yenziwa iphrofayili eqhubekayo. I-Extrusion ikhiqiza izinto ezinjengamapayipi/amashubhu, i-weatherstripping, uthango, ama-railing edekhi, amafreyimu amafasitela, amafilimu epulasitiki namashidi, ama-thermoplastic coatings, kanye nokufakwa kwezintambo.
Le nqubo iqala ngokuphakela izinto zepulasitiki (ama-pellets, ama-granules, ama-flakes noma izimpushana) kusuka ku-hopper kuya emgqonyeni we-extruder. Impahla kancane kancane incibilika amandla mechanical ekhiqizwa turning ngezikulufo kanye heater ahlelwe eduze umgqomo. I-polymer encibilikisiwe ibe iphoqeleka ukuba ibe yi-die, eyenza i-polymer ibe umumo oqina ngesikhathi sokupholisa.
UMLANDO
Ipayipi extrusion
Izandulela zokuqala ze-extruder yesimanje zathuthukiswa ekuqaleni kwekhulu le-19. Ngo-1820, uThomas Hancock wasungula “i-masticator” yenjoloba eklanyelwe ukubuyisela izinsalela zenjoloba ezicutshunguliwe, kwathi ngo-1836 u-Edwin Chaffee wenza umshini onama-roller amabili ukuze axube izithasiselo zibe irabha. I-extrusion yokuqala ye-thermoplastic yayingo-1935 nguPaul Troester nomkakhe u-Ashley Gershoff eHamburg, eJalimane. Ngokushesha ngemva kwalokho, u-Roberto Colombo we-LMP wakha ama-scruder angamawele okuqala e-Italy.
INQUBO
Ku-extrusion yamapulasitiki, i-compound material eluhlaza ngokuvamile isesimweni se-nurdles (ubuhlalu obuncane, ngokuvamile obubizwa ngokuthi i-resin) obunamandla adonsela phansi asuka ku-hopper efakwe phezulu emgqonyeni we-extruder. Izithasiselo ezifana nama-colorants nama-UV inhibitors (kungaba yi-liquid noma ifomu le-pellet) zivame ukusetshenziswa futhi zingaxutshwa ku-resin ngaphambi kokufika ku-hopper. Le nqubo inokuningi okufanayo nokubunjwa komjovo wepulasitiki kusukela endaweni yobuchwepheshe be-extruder, nakuba ihluke ngokuthi ngokuvamile inqubo eqhubekayo. Ngenkathi i-pultrusion inganikeza amaphrofayili amaningi afanayo ngobude obuqhubekayo, imvamisa ngokuqiniswa okwengeziwe, lokhu kufezwa ngokukhipha umkhiqizo osuphelile endaweni yokufa esikhundleni sokukhipha incibilike ye-polymer ngokusebenzisa i-die.
Okubalulekile kungena ngomphimbo wokuphakelayo (imbobo eseduze nengemuva lombhobho) bese kuhlangana nesikulufu. Isikulufu esizungezayo (esivame ukuphenduka isb. 120 rpm) siphoqa ubuhlalu bepulasitiki bubheke phambili emgqonyeni oshisayo. Izinga lokushisa elifunayo le-extrusion alivamile ukulingana nezinga lokushisa elibekiwe lomgqomo ngenxa yokushisa kwe-viscous neminye imiphumela. Ezinqubweni eziningi, iphrofayili yokushisa isethelwe umgqomo lapho izindawo zokushisa ezilawulwa yi-PID ezizimele ezintathu noma ngaphezulu zikhuphula kancane kancane izinga lokushisa lomgqomo ukusuka ngemuva (lapho ipulasitiki ingena khona) ukuya ngaphambili. Lokhu kuvumela ubuhlalu bepulasitiki buncibilike kancane kancane njengoba buphushwa emgqonyeni futhi kwehlisa ingozi yokushisa ngokweqile okungase kubangele ukuwohloka kwe-polymer.
Ukushisa okwengeziwe kubangelwa ukucindezela okukhulu nokungqubuzana okwenzeka ngaphakathi komgqomo. Eqinisweni, uma ulayini we-extrusion usebenzisa izinto ezithile ngokushesha ngokwanele, izifudumezi zingavalwa futhi izinga lokushisa elincibilikayo ligcinwe ukucindezela nokungqubuzana kukodwa ngaphakathi komgqomo. Kuma-extruder amaningi, amafeni okupholisa akhona ukuze kugcinwe izinga lokushisa lingaphansi kwenani elimisiwe uma kukhiqizwa ukushisa okukhulu. Uma ukupholisa komoya okuphoqelelwe kukhombisa ukuthi akwanele, kusetshenziswa amajakhethi okupholisa afakwe ngaphakathi.
I-extruder yepulasitiki isike phakathi ukukhombisa izingxenye
Ngaphambili komgqomo, ipulasitiki encibilikisiwe ishiya isikulufu futhi idlule kuphakethe lesikrini ukuze isuse noma yikuphi ukungcola ekuncibilikeni. Izikrini ziqiniswa ipuleti le-breaker (i-puck yensimbi ewugqinsi enezimbobo eziningi ezibhobozwe kuyo) njengoba ingcindezi kuleli qophelo ingadlula ama-psi angu-5,000 (34 MPa). I-screen pack/breaker plate assembly iphinde isebenze ukudala ingcindezi engemuva emgqonyeni. Ingcindezi yasemuva iyadingeka ukuze kuncibilike okufanayo kanye nokuxutshwa okufanele kwe-polymer, nokuthi ingakanani ingcindezi ekhiqizwayo "ingashintshwa" ngokuhlukahluka kokwakheka kwephekhi lesikrini (inombolo yezikrini, usayizi wazo wokulukwa kwentambo, namanye amapharamitha). Le nhlanganisela yepuleti le-breaker nephakethe lesikrini iphinde iqede "inkumbulo ejikelezayo" yepulasitiki encibilikisiwe futhi idale, "inkumbulo yobude".
Ngemva kokudlula ipuleti le-breaker ipulasitiki encibilikisiwe ingena kudayi. Idayidi yilona elinikeza umkhiqizo wokugcina iphrofayili yawo futhi kufanele iklanywe ngendlela yokuthi ipulasitiki encibilikisiwe igeleze ngokulinganayo isuka kuphrofayili eyisilinda, iye esimweni sephrofayili yomkhiqizo. Ukugeleza okungalingani kulesi sigaba kungaveza umkhiqizo onezingcindezi eziyinsalela ezingafuneki ezindaweni ezithile kuphrofayili okungabangela ukungqubuzana lapho kupholisa. Izinhlobonhlobo zomumo zingadalwa, zikhawulelwe kumaphrofayili aqhubekayo.
Manje umkhiqizo kufanele upholiswe futhi lokhu kuvame ukufezwa ngokudonsa i-extrudate ngokusebenzisa okugeza kwamanzi. Amapulasitiki angama-insulators amahle kakhulu ashisayo ngakho-ke kunzima ukupholisa ngokushesha. Uma kuqhathaniswa nensimbi, ipulasitiki ihambisa ukushisa kwayo kancane izikhathi ezingu-2,000. Kulayini wokukhipha ishubhu noma wepayipi, ukugeza kwamanzi avaliwe kwenziwa ngevacuum elawulwa ngokucophelela ukuze kuvinjwe ishubhu noma ipayipi elisanda kwakheka nelisancibilikile ukuthi lingawi. Emikhiqizweni efana ne-plastic sheeting, ukupholisa kufinyelelwa ngokudonsa ngeqoqo lemiqulu yokupholisa. Kumafilimu kanye namashidi amancane kakhulu, ukupholisa komoya kungasebenza njengesiteji sokuqala sokupholisa, njengaku-extrusion yefilimu eshaywayo.
Ama-extruder epulasitiki nawo asetshenziswa kakhulu ukucubungula kabusha imfucuza yepulasitiki egaywe kabusha noma ezinye izinto zokusetshenziswa ngemuva kokuhlanza, ukuhlunga kanye/noma ukuhlanganisa. Lokhu okubalulekile kuvame ukukhishwa kube imicu elungele ukunqunywa kubuhlalu noma esitokisini se-pellet ukuze kusetshenziswe njengesandulela ukuze kuqhutshekwe nokucutshungulwa.
UKWENZIWA KWESIKHULU
Kunezindawo ezinhlanu ezingaba khona kusikulufa se-thermoplastic. Njengoba amagama asetshenziswayo engajwayelekile embonini, amagama ahlukene angabhekisa kulezi zindawo. Izinhlobo ezahlukene ze-polymer zizoba nemiklamo ehlukene yezikulufu, ezinye zingafaki zonke izindawo ezingaba khona.
Isikulufu esilula se-plastic extrusion
Izikulufu ze-Extruder ezivela eBoston Matthews
Izikulufu eziningi zinalezi zindawo ezintathu:
● Indawo yokuphakelayo (ebuye ibizwe ngokuthi indawo yokudlulisa okuqinile): le ndawo ifaka inhlaka ku-extruder, futhi ukujula kwesiteshi ngokuvamile kuyefana kuyo yonke indawo.
● Indawo encibilikayo (ebuye ibizwe ngokuthi indawo yoguquko noma yokuminyanisa): i-polymer eminingi iyancibilika kulesi sigaba, futhi ukujula kwesiteshi kuba kuncane kancane kancane.
● Indawo yokukala (ebuye ibizwe ngokuthi indawo yokudlulisa encibilika): le ndawo incibilikisa izinhlayiya zokugcina futhi ixubane nezinga lokushisa elifanayo kanye nokwakheka. Njengendawo yokuphakelayo, ukujula kwesiteshi kuhlala njalo kuyo yonke le ndawo.
Ngaphezu kwalokho, isikulufu esifakwe umoya (izigaba ezimbili) sine:
● Indawo yokuncipha. Kule ndawo, cishe izingxenye ezimbili kwezintathu ezansi nesikulufu, isiteshi siya ngokuya sijula, esikhulula ukucindezela futhi sivumele noma imaphi amagesi avaleleke (umswakama, umoya, izincibilikisi, noma izinto ezisabelayo) ukuthi akhishwe nge-vacuum.
● Indawo yemitha yesibili. Le zoni iyafana nendawo yokuqala yokukala, kodwa inokujula kwesiteshi. Isebenza ukucindezela kabusha ukuncibilika ukukuthola ngokumelana nezikrini kanye nokufa.
Ngokuvamile ubude bezikulufu bubhekiselwa kububanzi baso njengesilinganiso se-L:D. Isibonelo, isikulufu esingu-6-intshi (150 mm) ububanzi ku-24:1 sizoba amayintshi angu-144 (12 ft) ubude, futhi ngo-32:1 singayiyintshi engu-192 (16 ft) ubude. Isilinganiso se-L:D esingu-25:1 sivamile, kodwa eminye imishini ikhuphukela ku-40:1 ukuze uthole ukuxuba okwengeziwe nokukhipha okwengeziwe kububanzi besikulufu esifanayo. Izikulufu ezinezigaba ezimbili (ezifakwe umoya) ngokuvamile zingu-36:1 ukuze zichaze izindawo ezimbili ezengeziwe.
Indawo ngayinye ifakwe i-thermocouples eyodwa noma ngaphezulu noma ama-RTD odongeni lomgqomo wokulawula izinga lokushisa. "Iphrofayili yezinga lokushisa" okungukuthi, izinga lokushisa lendawo ngayinye libaluleke kakhulu kukhwalithi kanye nezici ze-extrudate yokugcina.
IZINTO EZIJWAYELEKILE ZOKUPHUMA
Ipayipi le-HDPE ngesikhathi sokukhipha. Impahla ye-HDPE ivela ku-heater, ingena kufayizi, bese ingena ethangini lokupholisa. Leli payipi le-Acu-Power conduit likhishwe ngokuhlanganyela - limnyama ngaphakathi nejakhethi eliwolintshi elincanyana, ukuze kuqondwe izintambo zikagesi.
Izinto zepulasitiki ezijwayelekile ezisetshenziswa ku-extrusion zihlanganisa kodwa azikhawulelwe kulokhu: i-polyethylene (PE), i-polypropylene, i-acetal, i-acrylic, inayiloni (i-polyamides), i-polystyrene, i-polyvinyl chloride (PVC), i-acrylonitrile butadiene styrene (ABS) kanye ne-polycarbonate.[4 ]
IZINHLOBO ZOKUFA
Kunezinhlobonhlobo zokufa ezisetshenziswa ku-plastiki extrusion. Nakuba kungase kube nomehluko obalulekile phakathi kwezinhlobo zokufa nokuba yinkimbinkimbi, konke okufayo kuvumela ukukhishwa okuqhubekayo kokuncibilika kwe-polymer, ngokuphambene nokucubungula okungaqhubeki njengokubunjwa komjovo.
I-extrusion yefilimu eshaywayo
Vula i-extrusion yefilimu yepulasitiki
Ukwenziwa kwefilimu yepulasitiki yemikhiqizo efana nezikhwama zokuthenga kanye namashidi aqhubekayo kufinyelelwa ngokusebenzisa umugqa wefilimu oshaywayo.
Le nqubo iyafana nenqubo yokukhishwa evamile kuze kube sekufeni. Kunezinhlobo ezintathu eziyinhloko zokufa ezisetshenziswa kule nqubo: i-annular (noma i-crosshead), isicabucabu, ne-spiral. I-Annular dies yiyona elula kakhulu, futhi incike kumzila we-polymer oncibilikayo eduze kwayo yonke ingxenye yesiphambano sokufa ngaphambi kokuphuma kufa; lokhu kungabangela ukugeleza okungalingani. Spider dies aqukethe mandrel emaphakathi exhunywe yangaphandle die ring nge inombolo "imilenze"; kuyilapho ukugeleza kuhambisana kakhulu kunasekufa kwe-annular, kukhiqizwa imigqa eminingi yokushisela eyenza ifilimu ibe buthaka. I-Spiral dies isusa inkinga yemigqa yokushisela nokugeleza kwe-asymmetrical, kodwa iyinkimbinkimbi kakhulu.
Ukuncibilika kupholiswa kancane ngaphambi kokushiya idayizi ukuze kukhiqizwe ishubhu elibuthaka njenge-semi-solid. Ububanzi laleli shubhu bunwetshwa ngokushesha ngomfutho womoya, futhi ishubhu idonselwa phezulu ngamarola, yelula ipulasitiki kuzo zombili izikhombisi-ndlela eziphambanayo nezokudwetshwa. Umdwebo nokuphephetha kubangela ukuthi ifilimu ibe izacile kuneshubhu elikhishiwe, futhi iphinde iqondanise ngokukhethayo amaketanga e-polymer molecular ohlangothini lapho ubona uhlobo lwepulasitiki oluningi kakhulu. Uma ifilimu idwetshwa ngaphezu kokushaywa kwayo (ububanzi beshubhu lokugcina buseduze nobubanzi obunwetshiwe) ama-molecule e-polymer azoqondaniswa kakhulu nesiqondiso sokudonsa, enze ifilimu enamandla kuleyo ndlela, kodwa engenamandla ekuqondeni okuphambene. . Ifilimu enobubanzi obukhulu kakhulu kunobubanzi obunwetshiwe izoba namandla engeziwe lapho ibheka khona, kodwa ibe mancane lapho idonsa khona.
Endabeni ye-polyethylene namanye ama-semi-crystalline polymers, njengoba ifilimu ipholisa icwebezela kulokho okwaziwa ngokuthi umugqa wesithwathwa. Njengoba ifilimu iqhubeka nokuphola, idwetshwa ngamasethi amaningana ama-nip roller ukuze ayenze isicaba ibe yishubhu eliyisicaba, elingase lihlakazwe noma lisikwe libe imiqulu emibili noma ngaphezulu yamashidi.
I-extrusion yeshidi/ifilimu
I-extrusion yeshidi/ifilimu isetshenziselwa ukukhipha amashidi epulasitiki noma amafilimu awugqinsi kakhulu ukuthi angashaywa. Kunezinhlobo ezimbili zokufa ezisetshenzisiwe: okumise okwe-T kanye nesiphanyeko sejazi. Inhloso yalokhu okufayo ukuhlela kabusha nokuqondisa ukugeleza kwe-polymer encibilikayo kusukela kokuphumayo okuyindilinga okukodwa ukusuka ku-extruder kuya ekugelezeni kweplani encane, eyisicaba. Kuzo zombili izinhlobo ze-die qinisekisa ukugeleza okungaguquki, okufanayo kuyo yonke indawo yengxenye yesiphambano sedayizi. Ukupholisa kuvame ukudonsa kusethi yamaroli okupholisa (ikhalenda noma amaroli “apholile”). Ku-extrusion yeshidi, lawa maroli akalethi nje kuphela ukupholisa okudingekile kodwa futhi anquma ukujiya kweshidi nokuthungwa kwendawo.[7] Ngokuvamile i-co-extrusion isetshenziselwa ukusebenzisa isendlalelo esisodwa noma ngaphezulu phezu kwesisekelo sezinto ukuze kutholwe izici ezithile ezifana nokumuncwa kwe-UV, ukuthungwa, ukumelana komoyampilo, noma ukubonakaliswa kwamandla.
Inqubo evamile yangemuva kokukhishwa kwesitokwe sephepha lepulasitiki i-thermoforming, lapho ishidi lishiselwa lize lithambe (ipulasitiki), futhi lakhiwe ngesikhunta libe yisimo esisha. Lapho kusetshenziswa i-vacuum, lokhu kuvame ukuchazwa ngokuthi ukwenza i-vacuum. Ukuma (okungukuthi, ikhono/ukuminyana okutholakalayo kweshidi elizodonswa esikhunjeni esingahlukahluka ekujuleni ukusuka kumayintshi angu-1 ukuya kwangu-36 ngokuvamile) kubaluleke kakhulu futhi kuthinta kakhulu izikhathi zomjikelezo wokwakheka kwamapulasitiki amaningi.
I-extrusion ye-tubing
Amashubhu anwetshiwe, njengamapayipi e-PVC, akhiqizwa kusetshenziswa amafa afanayo nalawo asetshenziswa ku-extrusion yefilimu eshaywayo. Ukucindezela okuhle kungasetshenziswa emigodini yangaphakathi ngephini, noma ukucindezela okungekuhle kungasetshenziswa kububanzi obungaphandle kusetshenziswa i-vacuum sizer ukuqinisekisa ubukhulu obulungile bokugcina. I-lumens eyengeziwe noma izimbobo zingase zethulwe ngokungeza ama-mandrels angaphakathi afanelekile ku-die.
I-Boston Matthews Medical Extrusion Line
Izinhlelo zokusebenza zamashubhu anezingqimba eziningi zihlala zikhona embonini yezimoto, imboni yamapayipi nokushisisa kanye nemboni yokupakisha.
Ngaphezulu kwe-jacket extrusion
I-over jacketing extrusion ivumela ukusetshenziswa kongqimba lwangaphandle lwepulasitiki ocingweni noma ikhebuli ekhona. Lena inqubo evamile yezintambo zokuvikela ukushisa.
Kunezinhlobo ezimbili ezihlukene zamathuluzi e-die asetshenziselwa ukumboza phezu kocingo, ishubhu (noma i-jacketing) nokucindezela. Ekusebenziseni i-jacketing, i-polymer encibilika ayiyithinti intambo yangaphakathi kuze kube ngokushesha ngaphambi kwezindebe ezifayo. Ekusetshenzisweni kokucindezela, ukuncibilika kuthinta ucingo lwangaphakathi isikhathi eside ngaphambi kokuba lufinyelele ezindebeni ezifayo; lokhu kwenziwa ngengcindezi ephezulu ukuze kuqinisekiswe ukunamathela okuhle kokuncibilika. Uma ukuxhumana okuseduze noma ukunamathela kuyadingeka phakathi kwesendlalelo esisha nocingo olukhona, ithuluzi lokucindezela liyasetshenziswa. Uma ukunamathela kungafuneki/kudingekile, kusetshenziswa amathuluzi e-jacketing esikhundleni salokho.
I-Coextrusion
I-Coextrusion i-extrusion yezendlalelo eziningi zezinto ngesikhathi esisodwa. Lolu hlobo lwe-extrusion lusebenzisa ama-extruder amabili noma ngaphezulu ukuze ancibilike futhi alethe umthamo oqinile we-volumetric wamapulasitiki e-viscous ahlukene ekhanda elilodwa le-extrusion (die) elizokhipha izinto ngendlela oyifunayo. Lobu buchwepheshe busetshenziswa kunoma yiziphi izinqubo ezichazwe ngenhla (ifilimu eshaywayo, i-overjacketing, ishubhu, ishidi). Ugqinsi lwesendlalelo kulawulwa isivinini esihlobene namasayizi ama-extruder angawodwana aletha izinto.
5 :5 Ukufakwa ngokubambisana kwesendlalelo seshubhu “yokukhama” yezimonyo
Ezimeni eziningi zomhlaba wangempela, i-polymer eyodwa ayikwazi ukuhlangabezana nazo zonke izimfuno zohlelo lokusebenza. I-compound extrusion ivumela okokusebenza okuhlanganisiwe ukuthi kukhishwe, kodwa i-coextrusion igcina izinto ezihlukene njengezendlalelo ezihlukene kumkhiqizo okhishiwe, okuvumela ukubekwa okufanele kwezinto ezinezici ezihlukile ezifana nokungena komoyampilo, amandla, ukuqina, nokumelana nokugqokwa.
I-Extrusion coating
I-Extrusion coating isebenzisa inqubo yefilimu ephephethwayo noma ephonsiwe ukumboza isendlalelo esengeziwe esitokisini esikhona sephepha, i-foil noma ifilimu. Isibonelo, le nqubo ingasetshenziswa ukuthuthukisa izici zephepha ngokulimboza nge-polyethylene ukuze likwazi ukumelana namanzi. I-extruded layer ingasetshenziswa futhi njenge-adhesive ukuhlanganisa ezinye izinto ezimbili ndawonye. I-Tetrapak iyisibonelo sokuhweba sale nqubo.
I-COMPOUND EXTRUSIONS
I-compounding extrusion yinqubo exuba ipholima elilodwa noma ngaphezulu nezithasiselo ukuze kunikezwe izinhlanganisela zepulasitiki. Okuphakelayo kungase kube ama-pellets, impushana kanye/noma uketshezi, kodwa umkhiqizo ngokuvamile usesimweni se-pellet, ukuze usetshenziswe kwezinye izinqubo zokwenza ipulasitiki ezifana nokukhipha kanye nokubumba umjovo. Njenge-extrusion yendabuko, kunobubanzi obubanzi bosayizi womshini ngokuya ngohlelo lokusebenza kanye nokuphumayo okufunayo. Ngenkathi ama-extruder e-single- noma e-double-screw engase asetshenziswe ku-extrusion yendabuko, isidingo sokuxutshwa okwanele ekuhlanganiseni kwe-extrusion kwenza ama-twin-screw extruder konke kube yimpoqo.
IZINHLOBO ZE-EXTRUDER
Kunezinhlobo ezimbili ezincane zama-extruder isikulufu esingamawele: ukuzungezisa ngokuhlanganyela kanye nokuzungezisayo. Leli gama lisho isiqondiso esihlobene isikulufa ngasinye esisotha ngokuqhathaniswa nesinye. Kumodi yokuzungezisa ngokuhlanganyela, zombili izikulufu ziphenduka ngokwewashi noma ngokuphikisana newashi; ekujikezeni okuphikisayo, isikulufu esisodwa sizungeza ngokwewashi kuyilapho esinye sisonta ngokuphambene newashi. Kuye kwaboniswa ukuthi, endaweni enikeziwe yesigaba esiphambanayo kanye nezinga lokugqagqana (i-intermeshing), i-axial velocity kanye nezinga lokuhlanganisa liphezulu kuma-extruder angamawele azungezayo. Kodwa-ke, i-pressure buildup iphezulu kuma-extruder ajikelezayo. Idizayini yesikulufu ivamise ukuba yi-modular ngokuthi izakhi ezihlukahlukene zokudlulisa nokuxuba zihlelwa kumashafti ukuze kuvunyelwe ukulungiswa kabusha okusheshayo koshintsho lwenqubo noma ukushintshwa kwezingxenye ngazinye ngenxa yokuguga noma ukugqwala. Osayizi bomshini basukela kokuncane njengo-12 mm kuya kubukhulu obungu-380mm
UBUHLE
Inzuzo enkulu ye-extrusion ukuthi amaphrofayili afana namapayipi angenziwa kunoma yikuphi ubude. Uma impahla iguquguquka ngokwanele, amapayipi angenziwa ubude obude ngisho nokugoqa ku-reel. Enye inzuzo yi-extrusion yamapayipi ane-coupler edidiyelwe kuhlanganise ne-rubber seal.
Isikhathi sokuthumela: Feb-25-2022
