NguAndy osuka kumzi-mveliso waseBaiyear
Ihlaziywe ngoNovemba 5, 2022
1. Izinga lokucutheka
Ifom kunye nokubalwa kwe-thermoplastic molding shrinkage Njengoko kukhankanyiwe ngasentla, izinto ezichaphazela i-thermoplastic molding shrinkage zilandelayo:
1.1 Iindidi zePlastiki Ngexesha lenkqubo yokubumba i-thermoplastics, ngenxa yokuguqulwa komthamo obangelwa yi-crystallization, uxinzelelo olunamandla lwangaphakathi, uxinzelelo olukhulu olushiyekileyo olukhenkcezileyo kwinxalenye yeplastiki, kunye ne-molecular orientation eyomeleleyo, izinga le-shrinkage liphezulu kuneeplastiki ze-thermosetting.Ukongeza, i-shrinkage emva kokubunjwa, ukushwabana emva kokunyangwa kwe-annealing okanye ukufuma kwimeko yokufuma kudla ngokuba kukhulu kunolo lweplastiki ye-thermosetting.
1.2 Iimpawu zamalungu eplastiki Xa imathiriyeli etyhidiweyo idibana nomphezulu womgodi, umaleko wangaphandle uphola ngoko nangoko ukwenza iqokobhe eliqinileyo elinoxinaniso olusezantsi.Ngenxa yokungahambi kakuhle kwe-thermal yeplastiki, umaleko wangaphakathi wenxalenye yeplastiki upholiswa kancinane ukwenza umaleko oqinileyo oxineneyo kunye nokuncipha okukhulu.Ke ngoko, ubukhulu bodonga, ukupholisa okucothayo, kunye nobungqingqwa obuphezulu bokuxinana kuya kuncipha kakhulu.Ukongezelela, ubukho okanye ukungabikho kofakelo kunye nokwakheka kunye nobuninzi bokufaka kuchaphazela ngokuthe ngqo ulwalathiso lokuhamba kwezinto, ukusabalalisa ubuninzi kunye nokumelana nokunciphisa, ngoko ke iimpawu zeplastiki zinempembelelo enkulu kubukhulu kunye nolwalathiso lokunciphisa.
1.3 Izinto ezifana nefom, ubukhulu kunye nokusabalalisa kwe-feed inlet ichaphazela ngokuthe ngqo isalathiso sokuhamba kwezinto, ukusabalalisa ubuninzi, ukutya okunoxinzelelo kunye nexesha lokubumba.Izibuko lokutyisa elithe ngqo kunye nezibuko lokutyisa elinecandelo elikhulu elinqamlezayo (ingakumbi icandelo elinqamlezileyo) linokuncipha okuncinci kodwa ulwalathiso olukhulu, kwaye izibuko elibanzi nelifutshane lokutyisa linomkhombandlela omncinci.Ngokusondeleyo kwi-port feed okanye ihambelana nolwalathiso lokuhamba kwezinto eziphathekayo, i-shrinkage inkulu.
1.4 Iimeko zokubumba Iqondo lokushisa lokubumba liphezulu, izinto ezityhidiweyo zipholile ngokukhawuleza, ukuxinwa kuphezulu, kwaye i-shrinkage inkulu, ngokukodwa kwizinto ze-crystalline, i-shrinkage inkulu ngenxa ye-crystallinity ephezulu kunye nokuguqulwa kwevolumu enkulu.Ukuhanjiswa kobushushu bokubumba kukwanxulumene nokupholisa kwangaphakathi nangaphandle kunye nokuxinana kwenxalenye yeplastiki, echaphazela ngqo
Ichaphazela ubungakanani kunye nolwalathiso lokucutheka kwenxalenye nganye.Ukongezelela, uxinzelelo lokubamba kunye nexesha libuye libe nempembelelo enkulu kwi-contraction, i-contraction incinci kodwa isalathiso sikhulu xa uxinzelelo luphezulu kwaye ixesha lide.Uxinzelelo lwenaliti luphezulu, umahluko we-viscosity wezinto ezityhidiweyo zincinci, uxinzelelo lwe-shear ye-interlayer luncinci, kwaye i-elastic rebound emva kokudilizwa inkulu, ngoko ke ukuncitshiswa kunokuncipha ngokufanelekileyo, ubushushu bezinto eziphathekayo buphezulu, ukushwabana kukhulu. , kodwa ulwalathiso luncinci.Ke ngoko, ukulungelelanisa ubushushu bokubumba, uxinzelelo, isantya sokutofa kunye nexesha lokupholisa kunye nezinye izinto ngexesha lokubumba kunokutshintsha ngokufanelekileyo ukuncipha kwenxalenye yeplastiki.
Xa uyila isikhunta, ngokoluhlu lwe-shrinkage yeeplastiki ezahlukeneyo, ubukhulu bodonga kunye nokumila kwenxalenye yeplastiki, ifom, ubungakanani kunye nokusabalalisa ichweba lokutya, izinga lokunciphisa inxalenye nganye yenxalenye yeplastiki inqunywe ngamava, kwaye ke ubungakanani bombhobho bubalwa.Kwiindawo zeplastiki ezichaneke kakhulu kwaye xa kunzima ukuqonda isantya sokuncipha, ezi ndlela zilandelayo kufuneka zisetyenziswe ukuyila ukubumba:
① Thatha isantya esincinci sokushwabana kwedayamitha yangaphandle yamalungu eplastiki, kunye nesantya esikhulu sokushwabana kwedayamitha yangaphakathi, ukuze ushiye indawo yokulungiswa emva kovavanyo lokungunda.
②Uvavanyo lokungunda lumisela ifom, ubungakanani kunye neemeko zokubumba zenkqubo yokungena.
③ Iindawo zeplastiki eziza kucutshungulwa emva kokuba zisetyenzwe ukumisela utshintsho lwe-dimensional (umlinganiselo kufuneka wenziwe emva kweeyure ezingama-24 emva kokudilizwa).
④ Lungisa umngundo ngokokucutheka.
⑤ Zama kwakhona ukubumba kwaye utshintshe iimeko zenkqubo ukuguqula kancinane ixabiso le-shrinkage ukuhlangabezana neemfuno zamalungu eplastiki.
2. Ubumanzi
2.1 I-fluidity ye-thermoplastics ingacazululwa ngokubanzi kuluhlu lwezalathisi ezifana ne-molecular weight, melt index, i-Archimedes spiral flow length, i-viscosity ebonakalayo kunye ne-flow ratio (ubude benkqubo / ubukhulu bodonga lweplastiki).Ubunzima bemolekyuli encinci, ukusabalalisa ubunzima bemolekyuli, ulwakhiwo olungalunganga lwemolekyuli, isalathiso esinyibilikayo esiphakamileyo, ubude bokuqukuqela okude, i-viscosity ephantsi ebonakalayo, kunye nomlinganiselo omkhulu wokuhamba, ukumanzi kulungile.ekubumbeni inaliti.Ngokweemfuno zoyilo lokungunda, ubumanzi beeplastiki ezisetyenziswa ngokuqhelekileyo bunokwahlulwa ngokweendidi ezintathu:
①Ulwelo oluhle PA, PE, PS, PP, CA, poly(4) methyl pentylene;
②I-polystyrene series resin (efana ne-ABS, AS), i-PMMA, i-POM, i-polyphenylene ether enomanzi aphakathi;
③IPC engenamanzi emdaka, i-PVC eqinile, i-polyphenylene ether, i-polysulfone, i-polyarylsulfone, i-fluoroplastic.
2.2 Ukunyibilika kweeplastiki ezahlukeneyo nako kuyatshintsha ngenxa yeemeko ezahlukeneyo zokubumba.Imiba ephambili enempembelelo zezi zilandelayo:
① Ukuphakama kweqondo lokushisa, ukuphakama kwezinto eziphathekayo, kodwa iiplastiki ezahlukeneyo zikwahluka, i-PS (ingakumbi impembelelo-impembelelo kunye nexabiso eliphezulu le-MFR), i-PP, i-PA, i-PMMA, i-polystyrene eguquliwe (efana ne-ABS, AS) , PC, CA kunye nezinye iiplastiki fluidity iyahluka kakhulu lobushushu.Kwi-PE, i-POM, ukunyuka kweqondo lokushisa okanye ukuncipha kunempembelelo encinci kwi-fluidity yayo.Ke ngoko, owokuqala kufuneka ahlengahlengise iqondo lobushushu ukulawula ubumanzi ngexesha lokubumba.
②Xa uxinzelelo lwenaliti lusanda, izinto ezityhidiweyo ziya kuchetywa kakhulu, kwaye ukumanzi kuya kwanda, ngakumbi i-PE kunye ne-POM zinovakalelo ngakumbi, ngoko ke uxinzelelo lwenaliti kufuneka luhlengahlengiswe ukuze kulawuleke umbane ngexesha lokubumba.
③Ifomu, ubungakanani, uyilo, uyilo lwenkqubo yokupholisa, ukuchasana nokuhamba kwezinto ezinyibilikisiweyo (ezifana nokugqitywa komphezulu, ubukhulu becandelo langaphambili, ukumila kombhobho, inkqubo yokukhupha) kunye nezinye izinto ezichaphazela ngokuthe ngqo ukuhamba kwezinto ezityhidiweyo kumgodi.Eyona nto ikhoyo ngaphakathi, ukuba ubushushu bezinto ezityhidiweyo ziyancipha kwaye ukuchasana kwe-fluidity kwanda, umbane uya kuncipha.Xa uqulunqa isikhunta, isakhiwo esifanelekileyo kufuneka sikhethwe ngokuhambelana ne-fluidity yeplastiki esetyenzisiweyo.Ngexesha lokubumba, ubushushu bezinto eziphathekayo, ubushushu bokubumba, uxinzelelo lwe-injection, isantya se-injection kunye nezinye izinto zinokulawulwa ukulungelelanisa ngokufanelekileyo imeko yokuzalisa ukuhlangabezana neemfuno zokubumba.
3. Ubukhazikhazi
I-Thermoplastics inokwahlulwa ibe ngamacandelo amabini: iiplastiki zekristale kunye ne-non-crystalline (eyaziwa nangokuthi i-amorphous) iiplastiki ngokokungabikho kwe-crystallization ngexesha le-condensation.
Into ebizwa ngokuba yi-crystallization phenomenon kukuba xa iplastiki itshintsha ukusuka kwimo etyhidiweyo ukuya kwi-condensation, iimolekyuli zihamba ngokuzimeleyo, ngokupheleleyo kwimeko ephazamisekileyo, kwaye iimolekyuli ziyeka ukuhamba ngokukhululekileyo, ngokwendawo eqingqiweyo, kwaye kukho ukuthambekela. ukwenza ilungiselelo lemolekyuli imodeli eqhelekileyo.isenzeko.
Njengomgangatho wokugweba ukubonakala kwezi ntlobo zimbini zeplastiki, kuxhomekeke ekuhleni kweenxalenye zeplastiki ezinodonga olungqingqwa.Ngokuqhelekileyo, izinto ze-crystalline zi-opaque okanye ziguquguqukayo (ezifana ne-POM, njl.), kunye nezixhobo ze-amorphous ziyabonakala (ezifana ne-PMMA, njl.).Kodwa kukho izinto ezingafaniyo, ezifana ne-poly (4) i-methyl pentylene yi-crystalline crystalline kodwa inokukhanya okuphezulu, i-ABS yinto e-amorphous kodwa ayibonakali.
Xa uyila ukubumba kunye nokukhetha umatshini wokubumba inaliti, ezi mfuno zilandelayo kunye nezilumkiso zeeplastiki zekristale kufuneka ziqatshelwe:
① Ubushushu obufunekayo ukuze ubushushu bezinto bunyuke ukuya kubushushu bokubumba bukhulu, kwaye izixhobo ezinomthamo omkhulu weplastiki kufuneka zisetyenziswe.
②Ubushushu obukhutshwa ngexesha lokupholisa bukhulu, ngoko ke kufuneka bupholiswe ngokupheleleyo.
③ Umahluko othile womxhuzulane phakathi kwemeko enyibilikisiweyo kunye nemeko eqinileyo inkulu, ukushwabana okubunjwayo kukhulu, kwaye imingxunya eshwabeneyo kunye nemingxuma ithanda ukwenzeka.
④Ukupholisa ngokukhawuleza, ubucwebe obuphantsi, ukushwabana okuncinci kunye nokubonakala okuphezulu.I-crystallinity ihambelana nobukhulu bodonga lwenxalenye yeplastiki, ubukhulu bodonga bupholile ngokukhawuleza, i-crystallinity iphezulu, i-shrinkage inkulu, kunye neempawu ezibonakalayo zilungile.Ke ngoko, izinto zekristale kufuneka zilawule ubushushu bokubumba njengoko kufuneka.
⑤ I-anisotropy ebalulekileyo kunye noxinzelelo olukhulu lwangaphakathi.Emva kokudiliza, iimolekyuli ezingabonakaliyo zivame ukuqhubeka ziqaqambile kwaye zikwimeko yokungalingani kwamandla, okulungele ukuguqulwa kunye ne-warpage.
⑥ Uluhlu lwamaqondo obushushu becrystallization lumxinwa, kwaye kulula ukujova izinto ezinganyibilikiyo kubumba okanye ukuvimba izibuko lokutyisa.
4. Iiplastiki ezingevani nobushushu kunye neeplastiki ezenziwe nge-hydrolyzed ngokulula
4.1 Uvakalelo lwe-Thermal luthetha ukuba ezinye iiplastiki zivakalelwa ngakumbi kubushushu, kwaye ixesha lokufudumeza lide kwiqondo lokushisa eliphezulu okanye i-cross-section ye-port yokutya incinci kakhulu, kwaye xa isenzo sokucheba sisikhulu, ubushushu bezinto eziphathekayo buyanda kwaye buxhomekeke. ukujika kwebala, ukuthotywa, kunye nokubola.Inolu phawu.iiplastiki zibizwa ngokuba ziiplastiki ezingeva bubushushu.Ezinje nge-PVC engqongqo, i-polyvinylidene chloride, i-vinyl acetate copolymer, i-POM, i-polychlorotrifluoroethylene, njl. emzimbeni womntu, izixhobo kunye nokungunda.Ngoko ke, ingqalelo kufuneka ihlawulwe kuyilo lokubumba, ukukhethwa koomatshini bokubumba inaliti kunye nokubumba.Kufuneka kukhethwe oomatshini bokubumba inaliti yesikruru.I-cross-section ye-gating system kufuneka ibe nkulu.I-mold kunye ne-barrel kufuneka ibe yi-chrome-plated, kwaye akufanele kubekho iikona.Yongeza i-stabilizer ukwenza buthathaka iimpawu zayo ezingevani nobushushu.
4.2 Nokuba ezinye iiplastiki (ezifana nePC) zinomthamo omncinci wamanzi, ziya kubola phantsi kobushushu obuphezulu kunye noxinzelelo oluphezulu.Le propati ibizwa ngokuba yi-hydrolysis elula, ekufuneka ishushu kwaye yomiswe kwangaphambili.
5. Ukuqhekeka koxinzelelo kunye nokunyibilika kweqhekeza
5.1 Ezinye iiplastiki zinobuntununtunu kuxinzelelo, kwaye ziqhelene noxinzelelo lwangaphakathi ngexesha lokubunjwa kwaye zibhityile kwaye kulula ukuqhekeka.Amacandelo eplastiki aya kuqhekeka phantsi kwesenzo samandla angaphandle okanye i-solvent.Kule njongo, ngaphezu kokongeza izongezo kwizinto ezisetyenziselwa ukuphucula ukuchasana nokuqhekeka, ingqalelo kufuneka ihlawulwe ekomiseni izinto eziluhlaza, kwaye iimeko zokubumba kufuneka zikhethwe ngokufanelekileyo ukunciphisa uxinzelelo lwangaphakathi kunye nokwandisa ukuchasana nokuqhekeka.Ubume obufanelekileyo beengxenye zeplastiki kufuneka kukhethwe, kwaye imilinganiselo efana nokufakwa akufuneki imiselwe ukunciphisa uxinzelelo loxinzelelo.Xa uyila i-mold, i-slope ye-demolding kufuneka inyuswe, kwaye i-port enengqiqo yokutya kunye ne-ejection mechanism kufuneka ikhethwe.Ngexesha lokubumba, ubushushu bezinto eziphathekayo, iqondo lobushushu lokungunda, uxinzelelo lwenaliti kunye nexesha lokupholisa kufuneka luhlengahlengiswe ngokufanelekileyo ukunqanda ukudilizwa xa iinxalenye zeplastiki zibanda kakhulu kwaye zishwabene., Emva kokubunjwa, iinxalenye zeplastiki kufuneka ziphinde ziphathwe emva kokuphucula ukuchasana nokuqhekeka, ukuphelisa uxinzelelo lwangaphakathi kunye nokuthintela ukudibanisa ne-solvents.
5.2 Xa i-polymer enyibilika ngeqondo elithile lokunyibilika idlula kumngxuma wombhobho kwiqondo lobushushu elingaguqukiyo kwaye isantya sokuhamba kwayo singaphezulu kwexabiso elithile, iintanda ezicacileyo ezinqamlezayo kumphezulu wokunyibilika zibizwa ngokuba yi- melt fracture, eya konakalisa inkangeleko kunye neempawu ezibonakalayo iindawo zeplastiki.Ke ngoko, xa ukhetha iipolymers ezinezinga eliphezulu lokunyibilika kwenyibiliko, njl.njl., icandelo elinqamlezayo lombhobho, imbaleki, kunye nechweba lokutya kufuneka linyuswe, isantya senaliti kufuneka sincitshiswe, kwaye ubushushu bezinto kufuneka bonyuswe.
6. Ukusebenza kwe-thermal kunye nesantya sokupholisa
6.1 Iiplastiki ezahlukeneyo zineempawu ezahlukeneyo ze-thermal ezifana nobushushu obuthile, ukuhanjiswa kwe-thermal kunye nobushushu bokutshintsha kwe-thermal.Xa ukufakwa kweplastiki ngobushushu obuthile obuphezulu, ubushushu obuninzi bufunekayo, kwaye umatshini wokubumba umjovo kunye nomthamo omkhulu weplastiki kufuneka ukhethwe.Ixesha lokupholisa leplastiki elinobushushu obuphezulu bobugqwetha linokuba lifutshane kwaye ukudilizwa kuselithuba, kodwa ukuguqulwa kokupholisa kufuneka kuthintelwe emva kokudilizwa.Iiplastiki ezine-conductivity ephantsi ye-thermal zinezinga lokupholisa elicothayo (elifana ne-ionic polymers, njl.), Ngoko ke kufuneka zipholiswe ngokupheleleyo, kwaye umphumo wokupholisa wesikhunta kufuneka uqiniswe.Iimbumba zembaleki ezishushu zifanelekile kwiiplastiki ezinobushushu obuthile obuphantsi kunye ne-thermal conductivity ephezulu.Iiplastiki ezinobushushu obuthile obukhulu, ukuguquguquka okuphantsi kwe-thermal, ubushushu obuphantsi be-thermal deformation kunye nesantya sokupholisa esicothayo akuncedi ukubumba ngesantya esiphezulu, kunye noomatshini bokubumba abafanelekileyo kufuneka bakhethwe kwaye ukupholisa komngundo kufuneka kuqiniswe.
6.2 Iiplastiki ezahlukeneyo ziyafuneka ukugcina izinga lokupholisa elifanelekileyo ngokweentlobo zazo kunye neempawu kunye nokumila kwamalungu eplastiki.Ngoko ke, isikhunta kufuneka sibekwe kunye nenkqubo yokufudumala kunye nokupholisa ngokweemfuno zokubumba ukugcina ubushushu obuthile bokubumba.Xa ubushushu bezinto eziphathekayo bunyusa ubushushu bomngundo, kufuneka bupholiswe ukuze kuthintelwe iindawo zeplastiki ukuba zingakhubeki emva kokudilizwa, unciphise umjikelo wokubumba, kwaye unciphise ikristale.Xa inkunkuma yeplastiki ubushushu akwanelanga ukugcina ngundo kwiqondo lobushushu elithile, ngundo kufuneka ixhotyiswe inkqubo yokufudumeza ukugcina ngundo kwiqondo elithile lobushushu ukulawula izinga lokupholisa, ukuqinisekisa fluidity, ukuphucula iimeko zokuzalisa okanye ukulawula iplastiki. iindawo aphole kancinane.Thintela ukupholisa okungalinganiyo ngaphakathi nangaphandle kweendawo zeplastiki ezinodonga olungqingqwa kwaye uphucule ubukhazikhazi.Kwabo bane-fluidity elungileyo, indawo enkulu yokubumba kunye nobushushu bezinto ezingalinganiyo, ngokwemiqathango yokubumba yamacandelo eplastiki, ukufudumeza okanye ukupholisa ngamanye amaxesha kusetyenziswa ngokungafaniyo okanye ukufudumeza kwendawo kunye nokupholisa kusetyenziswa kunye.Ngenxa yale njongo, isikhunta kufuneka sixhotyiswe ngokupholisa okuhambelanayo okanye inkqubo yokufudumala.
Ixesha lokuposa: Nov-29-2022
