1.1Impembelelo ye-HPMC kushicilelo lwe-3D yoshicilelo lodaka
1.1.1Isiphumo se-HPMC kwi-extrudability ye-3D yoshicilelo lodaka
Iqela elingenanto i-M-H0 ngaphandle kwe-HPMC kunye namaqela ovavanyo anomxholo we-HPMC we-0.05%, 0.10%, 0.20%, kunye ne-0.30% avunyelwe ukuba amele amaxesha ahlukeneyo, kwaye emva koko kwavavanywa ukumanzi.Ingabonwa ukuba ukufakwa kwe-HPMC Kuya kunciphisa kakhulu umbane wodaka;xa umxholo we-HPMC unyuswa ngokuthe ngcembe ukusuka kwi-0% ukuya kwi-0.30%, i-fluidity yokuqala yodaka iyancipha ukusuka kwi-243 mm ukuya kwi-206, 191, 167, kunye ne-160 mm, ngokulandelanayo.I-HPMC yipolymer ephezulu yeemolekyuli.Ziyakwazi ukudityaniswa kunye ukuze zenze isakhiwo sothungelwano, kwaye ukudibanisa kwe-cement slurry kunokunyuswa ngamacandelo e-encapsulating afana ne-Ca (OH) 2. I-Macroscopically, ukudibanisa komdaka kuphuculwe.Ngokwandiswa kwexesha lokuma, iqondo le-hydration yodaka liyanda.ukwanda, ulwelo olulahlekileyo ngokuhamba kwexesha.I-fluidity yeqela elingenanto i-M-H0 ngaphandle kwe-HPMC yehla ngokukhawuleza.Kwiqela lovavanyo kunye ne-0.05%, 0.10%, 0.20% kunye ne-0.30% ye-HPMC, iqondo lokuhla kwe-fluidity liye lancipha ngokuhamba kwexesha, kunye nodaka lodaka emva kokuma kwe-60 min yi-180, 177, 164, kunye ne-155 mm, ngokulandelanayo. .I-fluidity yi-87.3%, 92.7%, 98.2%, 96.8%.Ukudityaniswa kwe-HPMC kunokuphucula ngokubonakalayo amandla okugcina amanzi omdaka, okubangelwa ukuhlanganiswa kwe-HPMC kunye neemolekyuli zamanzi;ngakolunye uhlangothi, i-HPMC inokwenza ifilimu efanayo Inesakhiwo sothungelwano kwaye isonge i-samente, enciphisa ngokufanelekileyo ukuguquguquka kwamanzi kumdaka kwaye inomsebenzi othile wokugcinwa kwamanzi.Kuyafaneleka ukuba uqaphele ukuba xa umxholo we-HPMC u-0.20%, amandla okugcinwa kwe-mortar fluidity afikelela kwinqanaba eliphezulu.
Ubumanzi bodaka loshicilelo lwe-3D oluxutywe nezixa ezahlukeneyo ze-HPMC yi-160 ~ 206 mm.Ngenxa yeparameters ezahlukeneyo zomshicileli, uluhlu olucetyiswayo lwe-fluidity efunyenwe ngabaphandi abahlukeneyo bahlukile, njenge-150 ~ 190 mm, 160 ~ 170 mm.Ukusuka kwi-Figure 3, inokubonwa nge-intuitively Ingabonwa ukuba ukuchithwa kwe-3D yokushicilela udaka oluxutywe ne-HPMC ubukhulu becala kuluhlu olucetyiswayo, ngakumbi xa umxholo we-HPMC u-0.20%, umbane wodaka ngaphakathi kwemizuzu engama-60 ungaphakathi. uluhlu olucetyiswayo, olwanelisa ulwelo olufanelekileyo kunye nokuqina.Ngoko ke, nangona i-fluidity yodaka kunye nenani elifanelekileyo le-HPMC iyancitshiswa, nto leyo ekhokelela ekunciphiseni kwe-extrudability, isenayo i-extrudability elungileyo, ephakathi koluhlu olucetyiswayo.
1.1.2Isiphumo se-HPMC kwi-stackability ye-3D yoshicilelo lodaka
Kwimeko yokungasebenzisi i-template, ubungakanani bezinga lokugcinwa kwemilo phantsi kobunzima bokuzimela buxhomekeke kuxinzelelo lwesivuno sezinto eziphathekayo, ezihambelana nokubambisana kwangaphakathi phakathi kwe-slurry kunye ne-aggregate.Ukugcinwa kwemilo ye-3D yoshicilelo lwe-3D kunye nemixholo eyahlukeneyo ye-HPMC inikwe.Izinga lotshintsho kunye nexesha lokuma.Emva kokongeza i-HPMC, izinga lokugcinwa kwemilo yodaka liphuculwe, ngakumbi kwinqanaba lokuqala kunye nokuma kwe-20 min.Nangona kunjalo, ngokongezwa kwexesha lokuma, isiphumo sophuculo se-HPMC kwireyithi yokugcinwa kwemilo yodaka ngokuthe ngcembe iye yaba buthathaka, nto leyo ibibangelwa ubukhulu becala ukuba izinga lokugcinwa linyuka kakhulu.Emva kokuma i-60 min, kuphela i-0.20% kunye ne-0.30% ye-HPMC inokuphucula izinga lokugcinwa kwemilo yodaka.
Iziphumo zokuvavanya ukuchasana nokungena kwe-3D yokushicilela i-3D kunye nemixholo eyahlukeneyo ye-HPMC iboniswe kwi-Figure 5. Ingabonwa kwi-Figure 5 ukuba ukuchasana nokungena ngokuqhelekileyo kwanda kunye nokwandiswa kwexesha lokuma, okubangelwa kakhulu ukuhamba kwe-. i-slurry ngexesha lenkqubo ye-cement hydration.Yakhula ngokuthe ngcembe yaba sisiqina esiqinileyo;kwi-80 min yokuqala, ukufakwa kwe-HPMC kwandise ukuchasana nokungena, kunye nokunyuka komxholo we-HPMC, ukuchasana nokungena kwanda.Okukhulu ukuchasana nokungena, ukuguqulwa kwezinto ngenxa yomthwalo osetyenziswayo Ukuxhatshazwa okukhulu kwe-HPMC yi, nto leyo ebonisa ukuba i-HPMC inokuphucula ukuqina kwangaphambili kodaka lokushicilela lwe-3D.Ekubeni i-hydroxyl kunye neebhondi ze-ether kwikhonkco le-polymer ye-HPMC zidityaniswa ngokulula namanzi ngokusebenzisa iibhondi ze-hydrogen, okukhokelela ekuncipheni ngokuthe ngcembe kwamanzi asimahla kunye noqhagamshelwano phakathi kwamasuntswana ukwanda, amandla okukhuhlana ayanda, ngoko ke ukuxhathisa kokungena kwangethuba kuba kukhulu.Emva kokuma imizuzu ye-80, ngenxa ye-hydration ye-samente, ukuchasana kokungena kweqela elingenanto ngaphandle kwe-HPMC kwanda ngokukhawuleza, ngelixa ukuchasana nokungena kweqela lokuvavanya kunye ne-HPMC kwanda Umlinganiselo awuzange utshintshe kakhulu kude kube malunga ne-160 min yokuma.Ngokutsho kuka-Chen et al., oku kubangelwa ukuba i-HPMC yenza ifilimu ekhuselayo malunga neengqungquthela zesamente, ezandisa ixesha lokumisela;Pourchez et al.kucingelwa ukuba oku kubangelwa ikakhulu kwifayibha Iimveliso zokuthotywa kwe-ether ezilula (ezifana ne-carboxylates) okanye amaqela e-methoxyl anokulibazisa ukuhanjiswa kwe-samente ngokunciphisa ukubunjwa kwe-Ca (OH)2.Kuyafaneleka ukuba uqaphele ukuba, ukuze kuthintelwe ukuphuhliswa kokumelana nokungena ekuchatshazweni kukuphuma kwamanzi phezu komfanekiso, Olu vavanyo lwenziwa phantsi kweemeko ezifanayo zokushisa kunye nokufuma.Lilonke, i-HPMC inokuphucula ngokufanelekileyo ukuzinza kodaka loshicilelo lwe-3D kwinqanaba lokuqala, ukulibazisa ukudibanisa, kunye nokwandisa ixesha eliprintwayo lodaka loshicilelo lwe-3D.
Iqumrhu lodaka loshicilelo lwe-3D (ubude be-200 mm × ububanzi 20 mm × umaleko ubukhulu 8 mm): Iqela elingenanto ngaphandle kwe-HPMC lakhubazeka kakhulu, lawa kwaye lanengxaki yokopha xa kushicilelwa umaleko wesixhenxe;Udaka lweqela le-M-H0.20 lunokuqina okuhle.Emva kokuprinta iileya ezili-13, ububanzi bomphetho ongaphezulu yi-16.58 mm, ububanzi bomphetho ophantsi yi-19.65 mm, kunye nomlinganiselo ophezulu ukuya ezantsi (umyinge wobubanzi obuphezulu ukuya kububanzi obusezantsi) yi-0.84.Ukutenxa komda kuncinci.Ke ngoko, kuye kwaqinisekiswa ngokushicilelwa ukuba ukufakwa kwe-HPMC kunokuphucula kakhulu ukuprintwa kodaka.I-Mortar fluidity ine-extrudability elungileyo kunye ne-stackability kwi-160 ~ 170 mm;izinga lokugcinwa kwemilo lingaphantsi kwama-70 % lonakele kakhulu kwaye alukwazi ukuhlangabezana neemfuno zoshicilelo.
1.2Impembelelo ye-HPMC kwiipropati ze-rheological zodaka loshicilelo lwe-3D
I-viscosity ebonakalayo ye-pulp ecocekileyo phantsi komxholo we-HPMC eyahlukileyo inikwe: ngokunyuka kwesantya sokucheba, i-viscosity ebonakalayo ye-pulp ecocekileyo iyancipha, kwaye i-phenomenon ye-shear thinning iphantsi komxholo ophezulu we-HPMC.Icace ngakumbi.Ikhonkco lemolekyuli ye-HPMC iphazamisekile kwaye ibonisa i-viscosity ephezulu kwizinga eliphantsi lokucheba;kodwa kwizinga eliphezulu lokucheba, iimolekyuli ze-HPMC zihamba ngokunxuseneyo kwaye zicwangciswe ecaleni kwendlela yokucheba, zenza iimolekyuli zibe lula ukutyibilika, ngoko ke itafile I-viscosity ebonakalayo ye-slurry iphantsi.Xa izinga le-shear likhulu kune-5.0 s-1, i-viscosity ebonakalayo ye-P-H0 kwiqela elingenanto lizinzile ngokusisiseko ngaphakathi kwe-5 Pa;ngelixa i-viscosity ebonakalayo yokwanda kwe-slurry emva kokuba i-HPMC yongezwa, kwaye ixutywe ne-HPMC.Ukongezwa kwe-HPMC kwandisa ukungqubuzana kwangaphakathi phakathi kweengqungquthela zesamente, okwandisa i-viscosity ebonakalayo ye-paste, kunye nokusebenza kwe-macroscopic kukuba i-extrudability yodaka lokushicilela lwe-3D luyancipha.
Ubudlelwane phakathi koxinzelelo lwe-shear kunye nesantya se-shear ye-slurry ecocekileyo kuvavanyo lwe-rheological yarekhodwa, kwaye imodeli ye-Bingham yayisetyenziselwa ukulungelelanisa iziphumo.Iziphumo ziboniswe kwi-Figure 8 kunye neThebhile 3. Xa umxholo we-HPMC ngu-0.30%, izinga le-shear ngexesha lovavanyo lalilikhulu kune-32.5 Xa i-viscosity ye-slurry idlula uluhlu lwesixhobo kwi-s-1, idatha ehambelanayo. amanqaku akanakuqokelelwa.Ngokuqhelekileyo, indawo evalelwe ngamagophe anyukayo nawayo kwinqanaba elizinzile (10.0 ~ 50.0 s-1) isetyenziselwa ukubonakalisa i-thixotropy ye-slurry [21, 33].Thixotropy ibhekisa kwipropati ukuba i-slurry ine-fluidity enkulu phantsi kwesenzo sokucheba ngamandla angaphandle, kwaye inokubuyela kwimeko yayo yangaphambili emva kokuba isenzo sokucheba sirhoxisiwe.I-thixotropy efanelekileyo ibaluleke kakhulu ukuprintwa kodaka .Ingabonwa kwi-Figure 8 ukuba indawo ye-thixotropic yeqela elingenanto ngaphandle kwe-HPMC yayiyi-116.55 Pa / s kuphela;emva kokongeza i-0.10% ye-HPMC, indawo ye-thixotropic ye-net paste inyuke kakhulu kwi-1 800.38 Pa / s;Ngokunyuka kwe-, indawo ye-thixotropic ye-paste iyancipha, kodwa yayisekho amaxesha angama-10 aphezulu kunelo qela elingenanto.Ukususela kumbono we-thixotropy, ukufakwa kwe-HPMC kuphucule kakhulu ukuprintwa kodaka.
Ukuze udaka lugcine ubume balo emva kwe-extrusion kunye nokumelana nomthwalo we-extruded layer elandelayo, udaka kufuneka lube noxinzelelo oluphezulu lwesivuno.Inokubonwa kwiThebhile 3 ukuba uxinzelelo lwesivuno τ0 lwe-slurry yomnatha luphuculwe kakhulu emva kokuba i-HPMC yongezwe, kwaye iyafana ne-HPMC.Umxholo we-HPMC unxibelelene kakuhle;xa umxholo we-HPMC ngu-0.10%, 0.20%, kunye ne-0.30%, uxinzelelo lwesivuno se-net paste luyanda ukuya kwi-8.6, 23.7, kunye ne-31.8 amaxesha eqela elingenanto, ngokulandelanayo;i-viscosity yeplastiki μ nayo yonyuka ngokunyuka komxholo we-HPMC.Ukushicilelwa kwe-3D kufuna ukuba i-viscosity yeplastiki yodaka akufanele ibe yincinci kakhulu, ngaphandle koko i-deformation emva kwe-extrusion iya kuba enkulu;ngelo xesha, i-viscosity yeplastiki efanelekileyo kufuneka igcinwe ukuze kuqinisekiswe ukuhambelana kwezinto ezibonakalayo.Isishwankathelo, ukusuka kwindawo yokujonga i-rheology, i-HPMC's Incorporation inefuthe elihle ekuphuculeni ukuqina kwe-3D yokushicilela udaka.Emva kokubandakanya i-HPMC, i-paste ecocekileyo isahambelana nemodeli ye-rheological ye-Bingham, kwaye ukulunga kwe-R2 efanelekileyo ayikho ngaphantsi kwe-0.99.
1.3Isiphumo se-HPMC kwiipropati zoomatshini bodaka loshicilelo lwe-3D
I-28 d amandla oxinzelelo kunye namandla okuguquguquka kwe-3D yokushicilela udaka.Ngokunyuka komxholo we-HPMC, i-28 d yoxinzelelo kunye namandla okuguquguquka kwe-3D yokushicilela udaka lwehla;xa umxholo we-HPMC ufikelele kwi-0.30%, i-28 d amandla oxinzelelo kunye Amandla okuguquguquka yi-30.3 kunye ne-7.3 MPa, ngokulandelanayo.Uphononongo lubonise ukuba i-HPMC inomphumo othile wokungena emoyeni, kwaye ukuba umxholo wayo uphezulu kakhulu, i-porosity yangaphakathi yodaka iya kwanda kakhulu;Ukuxhathisa ukusasazwa kuyenyuka kwaye kunzima ukukhupha konke.Ke ngoko, ukonyuka kwe-porosity inokuba sisizathu sokuncipha kwamandla odaka loshicilelo lwe-3D olubangelwa yi-HPMC.
Inkqubo eyodwa yokubumba i-lamination ye-3D yoshicilelo ikhokelela kubukho beendawo ezibuthathaka kwisakhiwo kunye neempawu zoomatshini phakathi kweeleya ezikufutshane, kwaye amandla okudibanisa phakathi kwamaleko anempembelelo enkulu kumandla onke ecandelo elishicilelweyo.Kwimizekelo yodaka loshicilelo lwe-3D oluxutywe ne-0.20% i-HPMC M-H0.20 yasikwa, kwaye amandla ebhondi ye-interlayer avavanywa yindlela yokwahlula i-interlayer.Amandla ebhondi ye-interlayer yamacandelo amathathu ayephezulu kune-1.3 MPa;kwaye xa inani lamaleko liphantsi, amandla e-interlayer bond ayephezulu kancinane.Isizathu sinokuthi, kwelinye icala, ubunzima bomgangatho ophezulu benza ukuba amaleko asezantsi adibane kakhulu;kwelinye icala, umphezulu wodaka unokuba nokufuma ngakumbi xa kushicilelwa umaleko ongezantsi, ngelixa ukufuma komphezulu wodaka kuncitshiswe ngenxa yokunyuka komphunga kunye ne-hydration xa kushicilelwa umaleko ongaphezulu, ngoko Ukudibanisa phakathi kwamaleko asezantsi kunamandla.
1.4Impembelelo ye-HPMC kwi-Micromorphology ye-3D Printing Mortar
Imifanekiso ye-SEM ye-M-H0 kunye ne-M-H0.20 ye-specimens kwi-3 d yobudala ibonisa ukuba i-surface pores ye-M-H0.20 imizekelo yanda kakhulu emva kokongeza i-0.20% ye-HPMC, kwaye ubukhulu bepore bukhulu kunobo iqela elingenanto.Oku Kwelinye icala, kungenxa yokuba i-HPMC inempembelelo yokungenisa umoya, eyazisa i-uniform kunye ne-fine pores;kwelinye icala, kusenokwenzeka ukuba ukongezwa kwe-HPMC kwandisa i-viscosity ye-slurry, ngaloo ndlela kwandisa ukunyanzeliswa kokukhutshwa komoya ngaphakathi kwe-slurry.Ukonyuka kunokuba sisizathu esiphambili sokunciphisa iimpawu zomatshini womdaka.Ukudibanisa, ukwenzela ukuba kuqinisekiswe amandla omdaka wokushicilela we-3D, umxholo we-HPMC akufanele ube mkhulu kakhulu (≤ 0.20%).
Ukuququmbela
(1) I-Hydroxypropyl methylcellulose HPMC iphucula ukuprintwa kodaka.Ngokunyuka komxholo we-HPMC, i-extrudability yodaka iyancipha kodwa isenayo i-extrudability elungileyo, ukuqiniswa kuphuculwe, kunye nokuprintwa Ixesha lide.Kuye kwaqinisekiswa ngokuprinta ukuba ukuguqulwa komgangatho ophantsi wodaka kuncitshiswe emva kokongeza i-HPMC, kwaye umlinganiselo ophezulu we-top-bottom ngu-0.84 xa umxholo we-HPMC ngu-0.20%.
(2) I-HPMC iphucula iipropati ze-rheological zodaka lokushicilela lwe-3D.Ngokunyuka komxholo we-HPMC, i-viscosity ebonakalayo, uxinzelelo lwesivuno kunye ne-plastiki viscosity yokwanda kwe-slurry;I-thixotropy inyuka kuqala kwaye iyancipha, kwaye ukuprintwa kufunyenwe.Uphuculo.Ukusuka kwimbono yerheology, ukongeza i-HPMC kunokuphucula ukuprintwa kodaka.Emva kokongeza i-HPMC, i-slurry isahambelana ne-Bingham rheological model, kunye nokulunga kwe-R2≥0.99 efanelekileyo.
(3) Emva kokongeza i-HPMC, i-microstructure kunye ne-pores yezinto zokwandisa.Kucetyiswa ukuba umxholo we-HPMC akufanele udlule i-0.20%, ngaphandle koko iya kuba nefuthe elikhulu kwiipropati zomatshini zodaka.Amandla okudibanisa phakathi kweeleya ezahlukeneyo zodaka loshicilelo lwe-3D ahluke kancinane, kunye nenani leeleya Xa iphantsi, amandla okudibanisa phakathi kweeleya zodaka aphezulu.
Ixesha lokuposa: Sep-27-2022