Lub npe Suav ntawm HPMC yog hydroxypropyl methylcellulose. Nws yog non-ionic thiab feem ntau yog siv los ua cov dej tuav hauv cov tshuaj khib nyiab qhuav. Nws yog cov khoom siv dej ntau tshaj plaws nyob rau hauv mortar.
Cov txheej txheem tsim khoom ntawm HPMC feem ntau yog polysaccharide-based ether cov khoom tsim los ntawm alkalization thiab etherification ntawm paj rwb fiber (hauv tsev). Nws tsis muaj nqi nws tus kheej, tsis hnov mob nrog cov ions raug nqi hauv cov khoom siv gelling, thiab muaj kev ua haujlwm ruaj khov. Tus nqi kuj tseem qis dua lwm hom cellulose ethers, yog li nws yog dav siv nyob rau hauv qhuav sib tov mortar.
Kev ua haujlwm ntawm hydroxypropyl methylcellulose: Nws tuaj yeem ua kom tuab cov tshuaj khib nyiab tshiab kom muaj cov viscosity ntub dej thiab tiv thaiv kev sib cais. (Thickening) Kev tuav dej kuj yog qhov tseem ceeb tshaj plaws, uas pab tswj cov dej dawb hauv cov mortar, yog li tom qab lub mortar tsim, cov khoom siv cementitious muaj sij hawm ntau rau hydrate. (Kev tuav dej) Nws muaj cov khoom siv cua nkag, uas tuaj yeem ua kom pom cov npuas zoo thiab zoo rau kev txhim kho kev tsim kho ntawm mortar.
Qhov siab dua qhov viscosity ntawm hydroxypropyl methylcellulose ether, qhov dej tuav tau zoo dua. Viscosity yog ib qho tseem ceeb parameter ntawm HPMC kev ua tau zoo. Tam sim no, cov tuam txhab HPMC sib txawv siv cov kev sib txawv thiab cov cuab yeej los ntsuas qhov viscosity ntawm HPMC. Cov txheej txheem tseem ceeb yog HaakeRotovisko, Hoppler, Ubbelohde thiab Brookfield.
Rau tib yam khoom, cov txiaj ntsig viscosity ntsuas los ntawm txoj kev sib txawv yog qhov sib txawv heev, thiab qee qhov muaj qhov sib txawv ob npaug. Yog li ntawd, thaum sib piv viscosity, nws yuav tsum tau nqa tawm ntawm tib txoj kev sim, nrog rau qhov kub thiab txias, rotor, thiab lwm yam. Hais txog particle loj, qhov finer particle, qhov zoo dua cov dej tuav. Tom qab cov khoom loj ntawm cellulose ether tuaj rau hauv kev sib cuag nrog dej, qhov chaw tam sim ntawd dissolves thiab tsim cov gel los qhwv cov khoom los tiv thaiv cov dej molecules los ntawm kev nkag mus ntxiv. Qee lub sij hawm nws tsis tuaj yeem sib cais thiab yaj txawm tias tom qab lub sij hawm ntev nplawm, tsim cov huab flocculent tov los yog agglomeration. Nws cuam tshuam rau cov dej tuav ntawm cellulose ether, thiab solubility yog ib qho tseem ceeb ntawm kev xaiv cellulose ether.
Fineness kuj yog ib qho tseem ceeb Performance index ntawm methyl cellulose ether. MC siv rau qhuav hmoov mortar yog yuav tsum tau hmoov, nrog dej tsawg, thiab cov fineness kuj yuav tsum tau 20% ~ 60% ntawm particle loj yuav tsum tsawg tshaj li 63um. Lub fineness cuam tshuam rau solubility ntawm hydroxypropyl methylcellulose ether. Coarse MC feem ntau yog granular, thiab nws yog ib qho yooj yim rau yaj nyob rau hauv dej tsis muaj agglomeration, tab sis lub dissolution tus nqi qeeb heev, yog li nws tsis haum rau siv nyob rau hauv qhuav hmoov mortar.
Nyob rau hauv qhuav hmoov mortar, MC yog dispersed ntawm cementing cov ntaub ntawv xws li aggregate, nplua muab tub lim thiab cement, thiab tsuas yog hmoov zoo txaus yuav zam methyl cellulose ether agglomeration thaum tov nrog dej. Thaum MC ntxiv nrog dej kom yaj cov agglomerates, nws nyuaj heev rau disperse thiab yaj. Coarse fineness ntawm MC tsis yog tsuas yog khib nyiab, tab sis kuj txo lub zog hauv zos ntawm mortar. Thaum xws li cov hmoov qhuav mortar yog siv rau hauv ib cheeb tsam loj, kev kho ceev ntawm cov hmoov qhuav hauv zos yuav txo qis, thiab cov kab nrib pleb yuav tshwm sim vim lub sijhawm sib txawv. Rau cov tshuaj txau nrog cov khoom siv kho tshuab, qhov yuav tsum tau ua kom zoo yog siab dua vim lub sijhawm sib xyaw luv. Feem ntau hais lus, qhov siab dua qhov viscosity, qhov zoo dua cov dej tuav. Txawm li cas los xij, qhov siab dua qhov viscosity thiab siab dua qhov hnyav molecular ntawm MC, qhov sib piv ntawm nws cov solubility yuav muaj kev cuam tshuam tsis zoo rau lub zog thiab kev tsim kho ntawm mortar.
Qhov siab dua qhov viscosity, qhov pom tseeb dua cov nyhuv thickening ntawm mortar, tab sis nws tsis ncaj qha proportional. Qhov siab dua qhov viscosity, qhov viscous ntau dua cov mortar ntub yuav, uas yog, thaum lub sij hawm tsim kho, nws yog manifested li sticking rau scraper thiab siab adhesion rau lub substrate. Tab sis nws tsis muaj txiaj ntsig los ua kom lub zog muaj zog ntawm cov mortar ntub nws tus kheej. Ntawd yog, thaum lub sij hawm tsim kho, qhov kev ua haujlwm tiv thaiv sag tsis pom tseeb. Ntawm qhov tsis sib xws, qee qhov nruab nrab thiab qis viscosity tab sis hloov kho methyl cellulose ethers muaj kev ua tau zoo hauv kev txhim kho lub zog ntawm cov khoom ntub dej.
Cov dej tuav ntawm HPMC kuj muaj feem xyuam rau qhov kub thiab txias siv, thiab cov dej tuav ntawm methyl cellulose ether txo qis nrog qhov kub thiab txias. Txawm li cas los xij, hauv kev siv cov khoom siv tiag tiag, cov hmoov av qhuav feem ntau siv rau cov khoom kub kub ntawm qhov kub siab (siab dua 40 degrees) hauv ntau qhov chaw, xws li sab nrauv phab ntsa putty plastering nyob rau hauv lub hnub nyob rau hauv lub caij ntuj sov, uas feem ntau accelerates curing ntawm cement thiab hardening. qhuav hmoov mortar. Qhov poob ntawm cov dej tuav tus nqi ua rau pom pom tseeb tias ob qho tib si kev ua haujlwm thiab kev ua haujlwm tawg tau cuam tshuam, thiab nws yog qhov tseem ceeb tshwj xeeb los txo qhov cuam tshuam ntawm qhov kub thiab txias hauv qhov xwm txheej no.
Nyob rau hauv no hais txog, methyl hydroxyethyl cellulose ether additives yog tam sim no suav hais tias yog nyob rau hauv pem hauv ntej ntawm kev tsim kho technology. Txawm hais tias tus nqi ntawm methyl hydroxyethyl cellulose yog nce (lub caij ntuj sov mis), kev ua hauj lwm thiab tawg kuj tseem tsis tuaj yeem ua tau raws li qhov xav tau ntawm kev siv. Los ntawm qee qhov kev kho tshwj xeeb ntawm MC, xws li nce qib ntawm etherification, thiab lwm yam, cov dej tuav tau tuaj yeem tswj tau ntawm qhov kub siab dua, kom nws tuaj yeem muab kev ua tau zoo dua hauv cov xwm txheej hnyav.
Qhov ntau npaum ntawm HPMC yuav tsum tsis txhob siab dhau, txwv tsis pub nws yuav ua rau kom cov dej xav tau ntawm cov mortar, nws yuav lo rau lub trowel, thiab lub sijhawm teem sijhawm yuav ntev dhau, uas yuav cuam tshuam rau kev tsim kho. Cov khoom siv khib nyiab sib txawv siv HPMC nrog cov viscosities sib txawv, thiab tsis txhob siv cov viscosity siab HPMC casually. Yog li ntawd, txawm hais tias cov khoom siv hydroxypropyl methylcellulose zoo, lawv tau qhuas thaum lawv siv tau zoo. Xaiv HPMC txoj cai yog lub luag haujlwm tseem ceeb ntawm cov neeg ua haujlwm hauv chaw kuaj mob. Tam sim no, ntau tus neeg muag khoom tsis paub cai yog sib xyaw HPMC, thiab qhov zoo yog qhov tsis zoo. Thaum xaiv ib qho cellulose, lub chaw soj nstuam yuav tsum ua txoj haujlwm zoo hauv kev sim kom muaj kev ruaj ntseg ntawm cov khoom mortar, thiab tsis txhob khav theeb rau pheej yig thiab ua rau tsis tsim nyog.
Post lub sij hawm: Dec-16-2022