Kupanga buku la HEMC cellulose ethers kuti muchepetse kuphatikizika kwa ma pulasitala opaka makina opangidwa ndi gypsum.

Kupanga buku la HEMC cellulose ethers kuti muchepetse kuphatikizika kwa ma pulasitala opaka makina opangidwa ndi gypsum.

pulasitala yopangidwa ndi makina opangidwa ndi Gypsum (GSP) yakhala ikugwiritsidwa ntchito kwambiri ku Western Europe kuyambira 1970s. Kutuluka kwa kupopera mbewu pamakina kwathandiza kuti ntchito yomanga pulasitala ikhale yolimba komanso kuchepetsa ndalama zomanga. Ndikukula kwa malonda a GSP, ether yosungunuka m'madzi ya cellulose yakhala chowonjezera chachikulu. Ma cellulose ether amapatsa GSP ntchito yabwino yosungira madzi, zomwe zimachepetsa kuyamwa kwa chinyezi mu pulasitala, potero kupeza nthawi yokhazikika komanso makina abwino amakina. Komanso, enieni rheological pamapindikira wa mapadi ether akhoza kusintha zotsatira za kupopera mbewu mankhwalawa makina ndi bwino kwambiri wotsatira matope kusalaza ndi kumaliza njira.

Ngakhale zabwino zodziwikiratu za ma cellulose ethers mu ntchito za GSP, zitha kuthandizanso kupanga zowuma zowuma zikapopera. Ma clumps osalowetsedwawa amadziwikanso kuti clumping kapena caking, ndipo amatha kusokoneza kukweza ndi kumaliza kwa matope. Agglomeration imatha kuchepetsa magwiridwe antchito a webusayiti ndikuwonjezera mtengo wazinthu zogwira ntchito kwambiri za gypsum. Kuti timvetse bwino zotsatira za ma cellulose ethers pakupanga minyewa mu GSP, tidachita kafukufuku kuyesa kuzindikira magawo ofunikira omwe amakhudza mapangidwe awo. Kutengera zotsatira za kafukufukuyu, tidapanga zinthu zingapo za cellulose ether zomwe zimakhala ndi chizolowezi chocheperako ndikuwunika momwe zimagwirira ntchito.

Mawu ofunikira: cellulose ether; gypsum makina opopera pulasitala; kuchuluka kwa kuwonongeka; particle morphology

1. Mawu Oyamba

Ma cellulose ethers osungunuka m'madzi agwiritsidwa ntchito bwino pamapulasitala opaka makina opangidwa ndi gypsum (GSP) kuwongolera kufunikira kwa madzi, kukonza kasungidwe ka madzi komanso kukonza mawonekedwe a matope a matope. Chifukwa chake, zimathandizira kukonza magwiridwe antchito a matope onyowa, potero kuwonetsetsa kuti matopewo akufunika mphamvu. Chifukwa cha zinthu zomwe zimagwira ntchito pazamalonda komanso zachilengedwe, zosakaniza zowuma za GSP zakhala zomangira zamkati zomwe zimagwiritsidwa ntchito kwambiri ku Europe pazaka 20 zapitazi.

Makina osakaniza ndi kupopera mankhwala owuma a GSP akhala akugulitsidwa bwino kwazaka zambiri. Ngakhale zina mwaukadaulo wa zida zochokera kwa opanga osiyanasiyana zimasiyanasiyana, makina onse opopera omwe amagulitsidwa amalola nthawi yochepa kwambiri yosokoneza madzi kuti asakanizike ndi cellulose ether-containing gypsum dry-mix mortar. Nthawi zambiri, kusakaniza konseko kumangotenga masekondi angapo. Pambuyo kusakaniza, matope onyowa amapopedwa kudzera mu payipi yoperekera ndikupopera pa khoma la gawo lapansi. Ntchito yonseyo imatsirizidwa mkati mwa miniti. Komabe, m'kanthawi kochepa, ma cellulose ethers amafunika kusungunuka kwathunthu kuti athe kukulitsa katundu wawo pakugwiritsa ntchito. Kuonjezera zopangira za cellulose ether ku matope a gypsum zimatsimikizira kusungunuka kwathunthu panthawi yopopera mbewuyi.

Finely ground cellulose ether amamanga kugwirizana mwamsanga pa kukhudzana ndi madzi mu mukubwadamuka mu sprayer. Kuchuluka kwa mamasukidwe akayendedwe kofulumira komwe kumachitika chifukwa cha kusungunuka kwa cellulose ether kumabweretsa mavuto ndi kunyowetsa kwamadzi nthawi yomweyo kwa tinthu tating'ono ta gypsum cementitious. Pamene madzi ayamba kukhuthala, amakhala ochepa madzimadzi ndipo sangathe kulowa mu pores ang'onoang'ono pakati pa gypsum particles. Pambuyo polowera ku pores kutsekedwa, kunyowetsa kwa tinthu tating'ono ta simenti ndi madzi kumachedwa. Kusanganikirana nthawi mu sprayer anali lalifupi kuposa nthawi yofunikira kuti mokwanira kunyowetsa gypsum particles, zomwe zinachititsa mapangidwe youma ufa clumps mu mwatsopano chonyowa matope matope. Maguluwa akapangidwa, amalepheretsa kugwira ntchito bwino kwa ogwira ntchito m'njira zotsatila: kusanja matope okhala ndi ma clumps kumakhala kovuta kwambiri ndipo kumatenga nthawi yochulukirapo. Ngakhale pambuyo poti matope akhazikika, zoyambira zomwe zidapangidwa zimatha kuwonekera. Mwachitsanzo, kuphimba zitsulo mkati mkati mwa ntchito yomanga kudzatsogolera ku maonekedwe a madera amdima pambuyo pake, zomwe sitikufuna kuziwona.

Ngakhale kuti ma cellulose ethers akhala akugwiritsidwa ntchito ngati zowonjezera mu GSP kwa zaka zambiri, zotsatira zake pakupanga minyewa yopanda madzi sikunaphunzirepo mpaka pano. Nkhaniyi ikupereka njira yokhazikika yomwe ingagwiritsidwe ntchito kumvetsetsa zomwe zimayambitsa kuphatikizika kuchokera ku kawonedwe ka cellulose ether.

2. Zifukwa zopangira ma clumps osalowetsedwa mu GSP

2.1 Kunyowetsa pulasitala

Kumayambiriro kwa kukhazikitsa pulogalamu yofufuzira, zifukwa zingapo zomwe zingatheke kuti apange ma clumps mu CSP anasonkhanitsidwa. Kenaka, kupyolera mu kusanthula kothandizidwa ndi makompyuta, vuto likuyang'ana ngati pali njira yothandiza yaukadaulo. Kupyolera mu ntchitoyi, njira yabwino yothetsera mapangidwe a ma agglomerates mu GSP idawunikidwa poyamba. Kuchokera pazolinga zonse zaukadaulo ndi zamalonda, njira yaukadaulo yosinthira kunyowetsa tinthu tating'ono ta gypsum ndi chithandizo chapamwamba sikuloledwa. Kuchokera kuzinthu zamalonda, lingaliro la kusintha zipangizo zomwe zilipo ndi zida zopopera mankhwala ndi chipinda chosakanikirana chopangidwa mwapadera chomwe chingatsimikizire kuti kusakaniza kokwanira kwa madzi ndi matope kumachotsedwa.

Njira ina ndikugwiritsa ntchito zonyowetsa ngati zowonjezera mu gypsum plaster formulations ndipo tapeza kale chilolezo cha izi. Komabe, kuwonjezera kwa chowonjezera ichi mosalephera kumakhudza kugwirira ntchito kwa pulasitala. Chofunika kwambiri, chimasintha zinthu zakuthupi zamatope, makamaka kuuma ndi mphamvu. Kotero ife sitinafufuze mozama mu izo. Kuphatikiza apo, kuwonjezera kwa zinthu zonyowetsa kumaganiziridwanso kuti kungakhale ndi zotsatira zoyipa pa chilengedwe.

Poganizira kuti cellulose ether ili kale gawo la gypsum-based plaster formulation, kukhathamiritsa kwa cellulose ether kumakhala njira yabwino kwambiri yomwe ingasankhidwe. Pa nthawi yomweyo, izo siziyenera kukhudza madzi posungira katundu kapena kuwononga rheological katundu pulasitala ntchito. Kutengera malingaliro omwe adanenedwa kale kuti m'badwo wamafuta osanyowetsedwa mu GSP ndi chifukwa cha kuwonjezereka kwachangu kwambiri kwa kukhuthala kwa cellulose ethers pambuyo pokhudzana ndi madzi panthawi yakugwedezeka, kuwongolera kusungunuka kwa ma cellulose ethers kunakhala cholinga chachikulu cha phunziro lathu. .

2.2 Kutha nthawi ya cellulose ether

Njira yosavuta yochepetsera kusungunuka kwa ma cellulose ethers ndikugwiritsa ntchito zinthu za granular grade. Choyipa chachikulu chogwiritsa ntchito njirayi mu GSP ndikuti tinthu tating'onoting'ono tating'ono sitisungunuka kwathunthu mkati mwa zenera lalifupi la 10-sekondi ya mupiringidzo mu sprayer, zomwe zimapangitsa kuti madzi asasungidwe. Kuphatikiza apo, kutupa kwa cellulose ether yosasungunuka pambuyo pake kumayambitsa kukhuthala pambuyo popaka pulasitala ndikukhudza ntchito yomanga, zomwe sitikufuna kuziwona.

Njira ina yochepetsera kusungunuka kwa ma cellulose ethers ndikulumikizanso pamwamba pa ma cellulose ethers ndi glyoxal. Komabe, popeza kuphatikizikako kumayendetsedwa ndi pH, kusungunuka kwa ma cellulose ethers kumadalira kwambiri pH ya njira yamadzi yozungulira. Phindu la pH la dongosolo la GSP losakanikirana ndi laimu la slaked ndilokwera kwambiri, ndipo zomangira zogwirizanitsa za glyoxal pamtunda zimatsegulidwa mwamsanga mutatha kukhudzana ndi madzi, ndipo kukhuthala kumayamba kukwera nthawi yomweyo. Chifukwa chake, chithandizo chamankhwala choterechi sichingakhale ndi gawo pakuwongolera kuchuluka kwa kusungunuka kwa GSP.

Nthawi ya kusungunuka kwa ma cellulose ethers imadaliranso kapangidwe kake ka tinthu. Komabe, mfundoyi sinalandire chidwi kwambiri mpaka pano, ngakhale kuti zotsatira zake ndizofunika kwambiri. Amakhala ndi kusungunuka kosalekeza [kg/(m2•s)], kotero kusungunuka kwawo ndi kukhuthala kwawo kumayenderana ndi malo omwe alipo. Mlingo uwu ukhoza kusiyana kwambiri ndi kusintha kwa morphology ya cellulose particles. M'mawerengedwe athu amaganiziridwa kuti kukhuthala kwathunthu (100%) kumafika pambuyo pa masekondi a 5 akusakaniza kusakaniza.

Mawerengedwe osiyana tinthu morphologies anasonyeza kuti ozungulira particles anali mamasukidwe akayendedwe 35% ya kukhuthala komaliza pa theka la nthawi kusanganikirana. Munthawi yomweyi, tinthu tating'onoting'ono ta cellulose ether timangofikira 10%. Tinthu tating'onoting'ono tomwe timapanga tating'ono tayamba kusungunuka pambuyo pake2.5 masekondi.

Zophatikizidwanso ndizoyenera kusungunuka kwa ma cellulose ethers mu GSP. Chepetsani kukulitsa kukhuthala koyambirira kwa masekondi opitilira 4.5. Kenako, mamasukidwe akayendedwe anakula mofulumira kufika mamasukidwe akayendedwe komaliza mkati 5 masekondi oyambitsa kusanganikirana nthawi. Mu GSP, kuchedwa kwanthawi yayitali kotereku kumapangitsa kuti dongosololi likhale ndi mawonekedwe otsika, ndipo madzi owonjezera amatha kunyowetsa tinthu tating'ono ta gypsum ndikulowa pores pakati pa tinthu tating'ono popanda kusokoneza.

3. Particle morphology ya cellulose ether

3.1 Kuyeza kwa particle morphology

Popeza mawonekedwe a cellulose ether particles ali ndi chidwi kwambiri pa solubility, choyamba m'pofunika kudziwa magawo kufotokoza mawonekedwe a mapadi etere particles, ndiyeno kuzindikira kusiyana sanali wetting Mapangidwe a agglomerates ndi makamaka zogwirizana chizindikiro. .

Tinapeza particle morphology ya cellulose ether ndi njira yowunikira zithunzi. The particle morphology of cellulose ethers imatha kudziwika bwino pogwiritsa ntchito SYMPATEC digito image analyzer (yopangidwa ku Germany) ndi zida zina zowunikira mapulogalamu. Magawo ofunikira kwambiri a tinthu tating'onoting'ono adapezeka kuti ndi kutalika kwa ulusi wowonetsedwa ngati LEFI(50,3) ndi m'mimba mwake womwe umawonetsedwa ngati DIFI(50,3). CHIKWANGWANI pafupifupi kutalika deta amaonedwa kuti zonse kutalika kwa ena kufalikira mapadi etere tinthu.

Nthawi zambiri tinthu kukula kugawa deta monga pafupifupi CHIKWANGWANI m'mimba mwake DIFI akhoza kuwerengeredwa potengera chiwerengero cha particles (lomwe likuimira 0), kutalika (kumatanthauza 1), dera (lomwe likuimira 2) kapena voliyumu (yomwe imadziwika ndi 3). Miyezo yonse ya tinthu tating'ono mu pepalali imatengera voliyumu ndipo chifukwa chake imawonetsedwa ndi mawu okwana 3. Mwachitsanzo, mu DIFI (50,3), 3 amatanthawuza kugawa kwa voliyumu, ndipo 50 amatanthauza kuti 50% ya kagawo kakang'ono kagawidwe ka tinthu kakang'ono kuposa mtengo wosonyezedwa, ndipo 50% ina ndi yaikulu kuposa mtengo womwe wasonyezedwa. Ma cellulose ether mawonekedwe a tinthu tating'onoting'ono amaperekedwa mu ma micrometer (µm).

3.2 Selulosi ether pambuyo tinthu morphology kukhathamiritsa

Poganizira zotsatira za tinthu pamwamba, tinthu Kutha nthawi ya mapadi etere particles ndi ndodo ngati tinthu mawonekedwe kwambiri zimadalira pafupifupi CHIKWANGWANI m'mimba mwake DIFI (50,3). Kutengera lingaliro ili, ntchito yachitukuko pa ma cellulose ether inali ndi cholinga chopeza zinthu zokhala ndi makulidwe okulirapo a fiber DIFI (50,3) kuti azitha kusungunuka bwino.

Komabe, kuwonjezeka kwautali wa fiber DIFI(50,3) sikuyembekezereka kutsagana ndi kuchuluka kwa tinthu tating'onoting'ono. Kuchulukitsa magawo onse awiri pamodzi kumapangitsa kuti tinthu tating'onoting'ono tomwe titha kusungunuka kwathunthu mkati mwa mphindi 10 za chipwirikiti cha kupopera mbewu mankhwalawa ndi makina.

Choncho, yabwino hydroxyethylmethylcellulose (HEMC) ayenera kukhala wokulirapo avareji CHIKWANGWANI awiri DIFI(50,3) pamene kusunga pafupifupi CHIKWANGWANI kutalika LEFI(50,3). Timagwiritsa ntchito njira yatsopano yopanga cellulose ether kuti tipange HEMC yabwino. The tinthu mawonekedwe a madzi sungunuka mapadi etero anapezedwa mwa ndondomeko kupanga ndi osiyana kwambiri ndi tinthu mawonekedwe a mapadi ntchito monga zopangira kupanga. M'mawu ena, kupanga ndondomeko amalola tinthu mawonekedwe kamangidwe ka mapadi ether kukhala palokha kupanga ake zopangira.

Zithunzi zitatu zowunikira ma electron maikulosikopu: imodzi mwa etere ya cellulose yopangidwa ndi njira yokhazikika, ndi imodzi ya ether ya cellulose yomwe imapangidwa ndi njira yatsopano yokhala ndi mainchesi akuluakulu a DIFI (50,3) kuposa zida zanthawi zonse. Zomwe zikuwonetsedwa ndi kapangidwe ka cellulose wopangidwa bwino kwambiri womwe umagwiritsidwa ntchito popanga zinthu ziwirizi.

Poyerekeza ma electron micrographs a cellulose ndi cellulose ether opangidwa ndi ndondomeko yoyenera, n'zosavuta kupeza kuti awiriwa ali ndi makhalidwe ofanana a morphological. Kuchuluka kwa tinthu ting'onoting'ono m'zithunzi zonse ziwirizi kumawonetsa mawonekedwe aatali, opyapyala, zomwe zikuwonetsa kuti mawonekedwe a morphological sanasinthe ngakhale kusintha kwamankhwala kwachitika. N'zoonekeratu kuti tinthu morphology makhalidwe a anachita mankhwala kwambiri correlated ndi zipangizo.

Iwo anapeza kuti morphological makhalidwe a mapadi etero opangidwa ndi ndondomeko latsopano ndi osiyana kwambiri, ali ndi lalikulu pafupifupi awiri DIFI (50,3), ndipo makamaka amapereka wozungulira lalifupi ndi wandiweyani tinthu akalumikidzidwa, pamene mmene woonda ndi yaitali particles. mu cellulose zopangira Pafupifupi kutha.

Chithunzichi chikuwonetsanso kuti tinthu tating'onoting'ono ta cellulose ethers opangidwa ndi njira yatsopanoyi sakhalanso ndi morphology ya cellulose yaiwisi - kugwirizana pakati pa morphology ya zopangira ndi mankhwala omaliza kulibenso.

4. Zotsatira za HEMC particle morphology pakupanga ma clumps osanyowa mu GSP

GSP idayesedwa pansi pamikhalidwe yofunsira kutsimikizira kuti malingaliro athu okhudza momwe amagwirira ntchito (kuti kugwiritsa ntchito mankhwala a cellulose ether okhala ndi mainchesi a DIFI (50,3) kungachepetse kuphatikizika kosafunikira) kunali kolondola. Ma HEMC okhala ndi ma diameter apakati DIFI(50,3) kuyambira 37 µm mpaka 52 µm adagwiritsidwa ntchito poyesa izi. Pofuna kuchepetsa chikoka cha zinthu zina osati particle morphology, gypsum pulasitala m'munsi ndi zina zonse zina sanasinthe. Kukhuthala kwa cellulose ether kunasungidwa mosalekeza panthawi ya mayeso (60,000mPa.s, 2% yankho lamadzimadzi, kuyeza ndi rheometer ya HAAKE).

Makina opopera a gypsum omwe amapezeka pamalonda (PFT G4) adagwiritsidwa ntchito kupopera mbewu pamayesero ogwiritsira ntchito. Yang'anani pakuwunika momwe ma clumps osalowetsedwa a matope a gypsum atangopaka khoma. Kuwunika kwa kuchulukana panthawiyi pakupanga pulasitala kudzawonetsa bwino kusiyana kwa magwiridwe antchito. Pakuyesaku, ogwira ntchito odziwa zambiri adavotera zomwe zidachitika, pomwe 1 ndiye wabwino kwambiri ndipo 6 adakhala woyipa kwambiri.

Zotsatira zoyeserera zikuwonetsa bwino kulumikizana pakati pa fiber diameter DIFI (50,3) ndi kuchuluka kwa magwiridwe antchito. Mogwirizana ndi malingaliro athu oti zinthu zopangidwa ndi cellulose ether zokhala ndi DIFI(50,3) zazikulu zidaposa zida zazing'ono za DIFI(50,3), avareji ya DIFI(50,3) ya 52 µm inali 2 (zabwino), pomwe omwe ali ndi DIFI( 50,3) ya 37µm ndi 40µm yagoletsa 5 (kulephera).

Monga momwe tinkayembekezera, kuphatikizika kwamachitidwe a GSP kumadalira kwambiri makulidwe a DIFI(50,3) a cellulose ether omwe amagwiritsidwa ntchito. Komanso, zinatchulidwa muzokambirana zam'mbuyomu kuti pakati pa magawo onse a morphological DIFI (50,3) adakhudza kwambiri nthawi ya kusungunuka kwa ma cellulose ether powders. Izi zimatsimikizira kuti nthawi yosungunuka ya cellulose ether, yomwe imagwirizana kwambiri ndi particle morphology, pamapeto pake imakhudza mapangidwe a clumps mu GSP. DIFI yokulirapo (50,3) imayambitsa nthawi yayitali ya kusungunuka kwa ufa, zomwe zimachepetsa kwambiri mwayi wa agglomeration. Komabe, nthawi yayitali kwambiri yosungunuka ufa imapangitsa kuti zikhale zovuta kuti cellulose ether isungunuke kwathunthu mkati mwa nthawi yoyambitsa zida zopopera.

Chogulitsa chatsopano cha HEMC chokhala ndi mbiri yabwino kwambiri yosungunuka chifukwa cha kuchuluka kwa fiber DIFI(50,3) sikuti kumangonyowetsa bwino ufa wa gypsum (monga momwe tawonera mu clumping evaluation), komanso sizikhudza Kusunga madzi mankhwala. Kusungidwa kwa madzi molingana ndi EN 459-2 sikunadziwike kuchokera kuzinthu za HEMC za viscosity yomweyo ndi DIFI(50,3) kuchokera ku 37µm mpaka 52µm. Miyezo yonse pambuyo pa mphindi 5 ndi mphindi 60 imagwera mkati mwazofunikira zomwe zikuwonetsedwa mu graph.

Komabe, zidatsimikiziridwanso kuti ngati DIFI(50,3) ikhala yayikulu kwambiri, tinthu tating'onoting'ono ta cellulose sidzasungunukanso kwathunthu. Izi zidapezeka poyesa DIFI(50,3) ya 59 µM mankhwala. Zotsatira zake zoyesa kusunga madzi pambuyo pa mphindi 5 ndipo makamaka pambuyo pa mphindi 60 zidalephera kukwaniritsa zofunikira.

5. Mwachidule

Ma cellulose ethers ndi zowonjezera zofunika pakupanga kwa GSP. Ntchito yofufuza ndi chitukuko cha mankhwala apa ikuyang'ana kugwirizana pakati pa particle morphology ya cellulose ethers ndi mapangidwe a clumps osasunthika (otchedwa clumping) pamene amapopera ndi makina. Zimachokera ku lingaliro la njira yogwirira ntchito kuti nthawi yowonongeka ya cellulose ether powder imakhudza kunyowa kwa gypsum powder ndi madzi ndipo motero kumakhudza mapangidwe a clumps.

Kutha nthawi zimadalira tinthu kapangidwe ka cellulose ether ndipo angapezeke ntchito digito chithunzi kusanthula zida. Mu GSP, mapadi etha ndi lalikulu avareji awiri a DIFI (50,3) ndi wokometsedwa makhalidwe kuvunda ufa, kulola nthawi yochuluka madzi kunyowetsa gypsum particles, motero n'zotheka akadakwanitsira odana agglomeration. Mtundu uwu wa ether wa cellulose umapangidwa pogwiritsa ntchito njira yatsopano yopangira, ndipo mawonekedwe ake a tinthu sadalira mawonekedwe apachiyambi a zopangira zopangira.

Avereji ya fiber diameter DIFI (50,3) imakhala ndi mphamvu yofunikira kwambiri pa clumping, yomwe yatsimikiziridwa ndikuwonjezera mankhwalawa ku malo ogulitsa makina opopera gypsum opoperapo mankhwala pamalopo. Kuphatikiza apo, mayeso opopera kumundawa adatsimikizira zotsatira za labotale: zinthu zabwino kwambiri za cellulose ether zokhala ndi DIFI yayikulu (50,3) zidasungunuka kwathunthu mkati mwa zenera la GSP mukubwadamuka. Choncho, mankhwala a cellulose ether omwe ali ndi anti-caking properties pambuyo pokonza mawonekedwe a tinthu amasungabe ntchito yosungira madzi yoyambirira.