Focus on Cellulose ethers

Zotsatira za HPMC pamatope osindikizira a 3D

1.1Mphamvu ya HPMC pa kusindikizidwa kwa matope osindikizira a 3D

1.1.1Zotsatira za HPMC pa extrudability ya matope osindikizira a 3D

Gulu lopanda kanthu la M-H0 lopanda HPMC ndi magulu oyesera omwe ali ndi HPMC ali ndi 0.05%, 0.10%, 0.20%, ndi 0.30% adaloledwa kuima kwa nthawi zosiyanasiyana, ndiyeno madziwo anayesedwa.Zitha kuwoneka kuti kuphatikizidwa kwa HPMC Idzachepetsa kwambiri madzi a matope;pamene zili HPMC pang'onopang'ono kuchuluka kwa 0% kuti 0,30%, ndi fluidity koyamba matope amachepetsa kuchokera 243 mm kwa 206, 191, 167, ndi 160 mm, motero.HPMC ndi mkulu maselo polima.Zitha kulumikizidwa wina ndi mzake kuti apange dongosolo la maukonde, ndipo kugwirizana kwa simenti slurry kungawonjezeke ndi encapsulating zigawo zikuluzikulu monga Ca (OH) 2. Macroscopically, cohesiveness wa matope bwino.Ndi kuwonjezereka kwa nthawi yoyima, mlingo wa hydration wa matope umawonjezeka.kuchuluka, fluidity kutayika pakapita nthawi.Kuthamanga kwa gulu lopanda kanthu la M-H0 popanda HPMC kunachepa mofulumira.Mu gulu experimental ndi 0.05%, 0.10%, 0.20% ndi 0.30% HPMC, mlingo wa kuchepa fluidity utachepa ndi nthawi, ndi fluidity matope pambuyo anaima kwa mphindi 60 anali 180, 177, 164, ndi 155 mm, motero. .The fluidity ndi 87.3%, 92.7%, 98.2%, 96.8%.Kuphatikizidwa kwa HPMC kumatha kusintha kwambiri mphamvu yosungiramo matope amadzimadzi, omwe amayamba chifukwa cha kuphatikiza kwa HPMC ndi mamolekyu amadzi;Komano, HPMC ikhoza kupanga filimu yofananayo Ili ndi dongosolo la maukonde ndi kukulunga simenti, yomwe imachepetsa bwino kuphulika kwa madzi mumatope ndipo imakhala ndi ntchito yosungiramo madzi.Ndikoyenera kudziwa kuti pamene zomwe zili mu HPMC ndi 0,20%, mphamvu yosungiramo madzi amatope imafika pamtunda wapamwamba kwambiri.

The fluidity wa 3D yosindikiza matope wothira mulingo wosiyana wa HPMC ndi 160 ~ 206 mm.Chifukwa cha magawo osiyanasiyana osindikizira, mitundu yovomerezeka ya fluidity yomwe akatswiri osiyanasiyana amapeza ndi yosiyana, monga 150 ~ 190 mm, 160 ~ 170 mm.Kuchokera pa Chithunzi 3, chikhoza kuwonedwa mwachidziwitso Zitha kuwoneka kuti kusungunuka kwa matope osindikizira a 3D osakanikirana ndi HPMC nthawi zambiri kumakhala mkati mwazovomerezeka, makamaka pamene HPMC ili ndi 0.20%, kusungunuka kwa matope mkati mwa mphindi 60 kuli mkati. osiyanasiyana analimbikitsa, amene amakwaniritsa fluidity yoyenera ndi stackability.Choncho, ngakhale kuti madzi a matope omwe ali ndi chiwerengero choyenera cha HPMC amachepetsedwa, zomwe zimabweretsa kuchepa kwa extrudability, zimakhalabe zabwino zowonjezera, zomwe zili mkati mwazovomerezeka.

1.1.2Zotsatira za HPMC pa stackability wa matope osindikizira a 3D

Pankhani yosagwiritsa ntchito template, kukula kwa mawonekedwe osungira mawonekedwe pansi pa kulemera kwake kumadalira kupsinjika kwa zokolola za zinthu, zomwe zimagwirizana ndi mgwirizano wamkati pakati pa slurry ndi aggregate.Kusungidwa kwa mawonekedwe a matope osindikizira a 3D okhala ndi zinthu zosiyanasiyana za HPMC kumaperekedwa.Mtengo wa kusintha ndi nthawi yoyima.Pambuyo powonjezera HPMC, mawonekedwe osungira matope amawongoleredwa, makamaka pagawo loyambirira ndikuyimilira kwa mphindi 20.Komabe, ndi kuwonjezereka kwa nthawi yoyimirira, kusintha kwa HPMC pa kusungirako mawonekedwe a matope pang'onopang'ono kunafowoka, zomwe makamaka chifukwa cha Kusungirako kumawonjezeka kwambiri.Pambuyo pa kuyima kwa mphindi 60, 0.20% yokha ndi 0.30% HPMC ingasinthe mawonekedwe osungira matope.

Zotsatira zoyesa kukana kulowa mkati mwa matope osindikizira a 3D okhala ndi zinthu zosiyanasiyana za HPMC zikuwonetsedwa mu Chithunzi 5. Zitha kuwoneka kuchokera pa Chithunzi 5 kuti kukana kulowa mkati kumawonjezeka ndikuwonjezera nthawi yoyimirira, yomwe makamaka chifukwa cha kuyenda kwa slurry panthawi ya simenti ya hydration.Pang'onopang'ono chinasintha kukhala cholimba cholimba;mu 80 min yoyamba, kuphatikizidwa kwa HPMC kunawonjezera kukana kulowa mkati, ndipo ndi kuwonjezeka kwa zomwe zili mu HPMC, kukana kulowa mkati kunakula.Kuchuluka kwa kukana kulowa, mapindikidwe azinthu chifukwa cha katundu wogwiritsidwa ntchito Kulimbana kwakukulu kwa HPMC ndiko, zomwe zimasonyeza kuti HPMC ikhoza kupititsa patsogolo stackability oyambirira a matope osindikizira a 3D.Popeza zomangira hydroxyl ndi etere pa unyolo polima wa HPMC mosavuta pamodzi ndi madzi kudzera m'mabanki wa haidrojeni, chifukwa kuchepetsa pang'onopang'ono madzi aulere ndi kugwirizana pakati pa particles kuwonjezeka, ndi mikangano mphamvu ukuwonjezeka, kotero kukana malowedwe oyambirira amakhala lalikulu.Atayima kwa mphindi za 80, chifukwa cha hydration ya simenti, kukana kulowa mkati mwa gulu lopanda kanthu popanda HPMC kunakula mofulumira, pamene kukana kulowa kwa gulu loyesera ndi HPMC kunawonjezeka Mlingowo sunasinthe kwambiri mpaka pafupi ndi 160 min.Malinga ndi Chen et al., Izi makamaka chifukwa HPMC imapanga filimu yotetezera kuzungulira tinthu ta simenti, zomwe zimatalikitsa nthawi yokhazikitsa;Pourchez et al.kuganiza kuti izi zimachitika makamaka chifukwa cha fiber Easy ether degradation products (monga carboxylates) kapena magulu a methoxyl amatha kuchedwetsa simenti hydration pochepetsa mapangidwe a Ca(OH)2.Ndikoyenera kudziwa kuti, pofuna kuteteza chitukuko cha kukana kulowa mkati kuti chisakhudzidwe ndi kutuluka kwa madzi pamtunda wa chitsanzo, kuyesera kumeneku kunachitika pansi pa kutentha ndi chinyezi chomwecho.Pazonse, HPMC imatha kukonza bwino kukhazikika kwa matope osindikizira a 3D poyambira, kuchedwetsa kukhazikika, ndikutalikitsa nthawi yosindikiza ya matope osindikizira a 3D.

Gulu la matope osindikizira a 3D (utali wa 200 mm × m'lifupi 20 mm × wosanjikiza makulidwe 8 ​​mm): Gulu lopanda kanthu lopanda HPMC linali lopunduka kwambiri, linagwa ndipo linali ndi mavuto otaya magazi posindikiza gawo lachisanu ndi chiwiri;Mtondo wa gulu la M-H0.20 uli ndi stackability wabwino.Pambuyo kusindikiza zigawo 13, m'lifupi m'mphepete mwapamwamba ndi 16.58 mm, m'lifupi m'mphepete mwake ndi 19.65 mm, ndi chiŵerengero chapamwamba mpaka pansi (chiŵerengero cha m'mphepete mwa pamwamba mpaka m'lifupi mwake) ndi 0,84.Kupatuka kwa dimensional ndikochepa.Chifukwa chake, zatsimikiziridwa ndi kusindikiza kuti kuphatikizidwa kwa HPMC kumatha kusintha kwambiri kusindikiza kwa matope.Mtondo fluidity ali extrudability wabwino ndi stackability pa 160 ~ 170 mm;mawonekedwe osungira mawonekedwe ndi ochepera 70 % ndi opunduka kwambiri ndipo sangathe kukwaniritsa zofunikira zosindikiza.

1.2Chikoka cha HPMC pa rheological katundu wa 3D matope osindikizira

Kuwoneka kowoneka bwino kwa zamkati koyera pansi pa zinthu zosiyanasiyana za HPMC kumaperekedwa: pakuwonjezeka kwa kumeta ubweya wa ubweya, mawonekedwe owoneka bwino a zamkati oyera amachepa, ndipo chodabwitsa cha kumeta ubweya wa ubweya chimakhala pansi pa HPMC yayikulu.Ndi zoonekeratu.The HPMC maselo unyolo ndi chisokonezo ndi kusonyeza kukhuthala apamwamba pa mlingo otsika kukameta ubweya;koma pamlingo waukulu wa kukameta ubweya, mamolekyu a HPMC amayenda mofanana ndi mwadongosolo motsatira njira yometa ubweya, zomwe zimapangitsa kuti mamolekyu azikhala osavuta kutsetsereka, kotero tebulo Kuwoneka kowoneka bwino kwa slurry kumakhala kochepa.Pamene kumeta ubweya wa ubweya ndi kwakukulu kuposa 5.0 s-1, mawonekedwe owoneka bwino a P-H0 mu gulu lopanda kanthu amakhala okhazikika mkati mwa 5 Pa s;pamene kukhuthala kowonekera kwa slurry kumawonjezeka pambuyo pa HPMC kuwonjezeredwa, ndipo imasakanizidwa ndi HPMC.Kuwonjezera kwa HPMC kumawonjezera kukangana kwamkati pakati pa particles simenti, zomwe zimawonjezera kukhuthala koonekera kwa phala, ndi ntchito yaikulu ndikuti extrudability ya matope osindikizira a 3D amachepetsa.

Ubale pakati pa kumeta ubweya wa ubweya ndi kumeta ubweya wa slurry koyera mu mayeso a rheological unalembedwa, ndipo chitsanzo cha Bingham chinagwiritsidwa ntchito kuti chigwirizane ndi zotsatira.Zotsatira zikuwonetsedwa mu Chithunzi 8 ndi Table 3. Pamene zomwe zili mu HPMC zinali 0.30%, kumeta ubweya wa ubweya panthawi ya mayesero kunali kwakukulu kuposa 32.5 Pamene kukhuthala kwa slurry kumadutsa chiwerengero cha chida pa s-1, deta yofanana. mfundo sizingasonkhanitsidwe.Nthawi zambiri, malo otsekedwa ndi makhoti okwera ndi otsika pagawo lokhazikika (10.0 ~ 50.0 s-1) amagwiritsidwa ntchito kusonyeza thixotropy wa slurry [21, 33].Thixotropy amatanthauza malo omwe slurry ali ndi madzi ambiri pansi pa kumeta ubweya wakunja, ndipo akhoza kubwerera ku chikhalidwe chake choyambirira chitatha kumeta ubweya.Zoyenera thixotropy ndizofunikira kwambiri kusindikizidwa kwa matope .Zitha kuwoneka kuchokera ku Chithunzi 8 kuti dera la thixotropic la gulu lopanda kanthu popanda HPMC linali 116.55 Pa / s yokha;mutatha kuwonjezera 0,10% ya HPMC, dera la thixotropic la phala la ukonde linakula kwambiri mpaka 1 800.38 Pa / s;Ndi kuwonjezeka kwa , dera la thixotropic la phala linachepa, koma linali nthawi 10 kuposa la gulu lopanda kanthu.Kuchokera pamalingaliro a thixotropy, kuphatikizidwa kwa HPMC kunathandizira kwambiri kusindikiza kwa matope.

Kuti matope akhalebe ndi mawonekedwe ake pambuyo pa extrusion ndi kupirira katundu wa wosanjikiza wotsatiridwa wotsatira, matope ayenera kukhala ndi kupsinjika kwakukulu kwa zokolola.Zitha kuwoneka kuchokera ku Table 3 kuti kupsinjika kwa zokolola τ0 za slurry ya ukonde kumakhala bwino pambuyo poti HPMC yawonjezeredwa, ndipo ikufanana ndi HPMC.Zomwe zili mu HPMC zimagwirizana bwino;pamene zomwe zili mu HPMC ndi 0.10%, 0.20%, ndi 0.30%, kupsinjika kwa zokolola za phala kumawonjezeka kufika 8.6, 23.7, ndi 31.8 nthawi za gulu lopanda kanthu, motero;kukhuthala kwa pulasitiki μ kumawonjezeranso ndi kuchuluka kwa zomwe zili mu HPMC.Kusindikiza kwa 3D kumafuna kuti kukhuthala kwa pulasitiki kwa matope kusakhale kochepa kwambiri, apo ayi mapindikidwe pambuyo pa extrusion adzakhala aakulu;nthawi yomweyo, pulasitiki mamasukidwe akayendedwe oyenera ayenera kukhalabe kuonetsetsa kugwirizana kwa extrusion zakuthupi.Mwachidule, kuchokera pamalingaliro a rheology, HPMC's Incorporation ili ndi zotsatira zabwino pakusintha kwakusakhazikika kwa matope osindikizira a 3D.Pambuyo pophatikiza HPMC, phala loyera limagwirizanabe ndi Bingham rheological model, ndipo ubwino wa R2 wokwanira siwotsika kuposa 0.99.

1.3Zotsatira za HPMC pazinthu zamakina za matope osindikizira a 3D

28d mphamvu yopondereza ndi mphamvu yosinthika ya matope osindikizira a 3D.Ndi kuwonjezeka kwa HPMC, mphamvu ya 28 d ndi flexural ya matope osindikizira a 3D inachepa;pamene zomwe zili mu HPMC zinafika ku 0.30%, 28 d compressive mphamvu ndi The flexural mphamvu ndi 30.3 ndi 7.3 MPa, motero.Kafukufuku wasonyeza kuti HPMC ili ndi zotsatira zina za mpweya, ndipo ngati zili pamwamba kwambiri, porosity yamkati ya matope idzawonjezeka kwambiri;Kukaniza kufalikira kumawonjezeka ndipo ndizovuta kutulutsa zonse.Choncho, kuwonjezeka kwa porosity kungakhale chifukwa cha kuchepa kwa mphamvu ya matope osindikizira a 3D chifukwa cha HPMC.

Wapadera lamination akamaumba ndondomeko 3D kusindikiza kumabweretsa kukhalapo kwa madera ofooka mu kapangidwe ndi katundu makina pakati pa zigawo moyandikana, ndi kugwirizana mphamvu pakati pa zigawo ndi chikoka chachikulu pa mphamvu zonse za chigawo kusindikizidwa.Kwa zitsanzo za matope osindikizira a 3D osakanikirana ndi 0.20% HPMC M-H0.20 adadulidwa, ndipo mphamvu ya chomangira cha interlayer chinayesedwa ndi njira yogawanitsa interlayer.Mphamvu ya mgwirizano wa interlayer ya magawo atatu inali yoposa 1.3 MPa;ndipo pamene chiwerengero cha zigawo anali otsika, interlayer chomangira mphamvu anali apamwamba pang'ono.Chifukwa chingakhale chakuti, kumbali imodzi, mphamvu yokoka ya pamwamba imapangitsa kuti zigawo zapansi zikhale zogwirizana kwambiri;Komano, pamwamba pa matope akhoza kukhala ndi chinyontho chochuluka pamene kusindikiza m'munsi wosanjikiza, pamene chinyezi cha pamwamba pa matope chimachepetsedwa chifukwa cha evaporation ndi hydration pamene kusindikiza kumtunda kwapamwamba, kotero Kugwirizana pakati pa zigawo zapansi kumakhala kolimba.

1.4Zotsatira za HPMC pa Micromorphology ya 3D Printing Mortar

Zithunzi za SEM za zitsanzo za M-H0 ndi M-H0.20 pa zaka 3 d zimasonyeza kuti pores pamwamba pa zitsanzo za M-H0.20 akuwonjezeka kwambiri pambuyo powonjezera 0.20% HPMC, ndipo kukula kwake ndi kwakukulu kuposa kwa gulu lopanda kanthu.Izi Kumbali imodzi, ndichifukwa chakuti HPMC ili ndi mphamvu yolowera mpweya, yomwe imayambitsa pores yunifolomu ndi yabwino;Komano, zikhoza kukhala kuti Kuwonjezera HPMC kumawonjezera mamasukidwe akayendedwe a slurry, potero kuwonjezera kutulutsa kukana kwa mpweya mkati slurry.Kuwonjezeka kungakhale chifukwa chachikulu cha kuchepa kwa makina a matope.Kufotokozera mwachidule, pofuna kutsimikizira mphamvu ya matope osindikizira a 3D, zomwe zili mu HPMC siziyenera kukhala zazikulu (≤ 0.20%).

Pomaliza

(1) Hydroxypropyl methylcellulose HPMC imathandizira kusindikiza kwa matope.Ndi kuwonjezeka kwa zomwe zili mu HPMC, kutulutsa kwa matope kumachepa koma kumakhalabe ndi extrudability yabwino, stackability imapangidwa bwino, ndipo kusindikizidwa Nthawi ikutalika.Zatsimikiziridwa ndi kusindikiza kuti kusinthika kwa gawo la pansi la matope kumachepetsedwa pambuyo powonjezera HPMC, ndipo chiŵerengero chapamwamba-pansi ndi 0.84 pamene HPMC ili ndi 0.20%.

(2) HPMC imapangitsa rheological katundu wa 3D kusindikiza matope.Ndi kuchuluka kwa HPMC zili, kukhuthala koonekera, zokolola kupsinjika ndi pulasitiki mamasukidwe akayendedwe a slurry kuwonjezeka;thixotropy poyamba amawonjezeka ndiyeno amachepetsa, ndipo kusindikizidwa kumapezeka.Kupititsa patsogolo.Kuchokera pamalingaliro a rheology, kuwonjezera HPMC kumathanso kupititsa patsogolo kusindikiza kwa matope.Pambuyo powonjezera HPMC, slurry imagwirizanabe ndi Bingham rheological model, ndi ubwino wa R2≥0.99.

(3) Pambuyo powonjezera HPMC, microstructure ndi pores zazinthu zimawonjezeka.Ndibwino kuti zomwe zili mu HPMC zisapitirire 0,20%, mwinamwake zidzakhudza kwambiri makina a matope.Mphamvu yolumikizana pakati pa zigawo zosiyanasiyana za matope osindikizira a 3D ndi osiyana pang'ono, ndipo chiwerengero cha zigawo Zikakhala zotsika, mphamvu ya mgwirizano pakati pa matope ndi apamwamba.


Nthawi yotumiza: Sep-27-2022
Macheza a WhatsApp Paintaneti!