Qhov viscosity ntawm methyl cellulose ether tseem ceeb npaum li cas rau gypsum mortar?

Qhov viscosity ntawm methyl cellulose ether tseem ceeb npaum li cas rau gypsum mortar?

Teb: Viscosity yog qhov tseem ceeb rau kev ua haujlwm ntawm methyl cellulose ether.

Feem ntau hais lus, qhov siab dua qhov viscosity, qhov zoo dua cov dej tuav cov nyhuv ntawm gypsum mortar. Txawm li cas los xij, qhov siab dua qhov viscosity, siab dua qhov hnyav molecular ntawm methyl cellulose ether, thiab kev txo qis hauv 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. Thaum lub sij hawm tsim kho, nws yog manifested raws li sticking rau lub 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. Tsis tas li ntawd, thaum lub sij hawm tsim kho, qhov kev ua tau zoo los tiv thaiv sag ntawm ntub mortar 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.

Qhov tseem ceeb npaum li cas ntawm cov cellulose ether rau mortar?

Teb: Lub fineness kuj yog ib qho tseem ceeb Performance index ntawm methyl cellulose ether. MC siv rau cov hmoov qhuav mortar yuav tsum yog cov hmoov uas muaj dej tsawg, thiab cov fineness kuj yuav tsum tau 20% mus rau 60% ntawm particle loj yuav tsum tsawg tshaj li 63m. Lub fineness cuam tshuam rau solubility ntawm methyl cellulose ether. Coarse MC feem ntau yog granular, uas yog ib qho yooj yim rau disperse thiab 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. Qee cov khoom siv hauv tsev yog flocculent, tsis yooj yim rau disperse thiab yaj hauv dej, thiab yooj yim rau agglomerate. 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 MC tsis yog tsuas yog khib nyiab xwb, tab sis kuj txo lub zog hauv zos ntawm mortar. Thaum cov hmoov qhuav qhuav no siv rau hauv thaj chaw loj, kev kho ceev ntawm cov tshuaj khib 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.

Qhov zoo ntawm MC kuj muaj qee yam cuam tshuam rau nws cov dej tuav. Feem ntau hais lus, rau methyl cellulose ethers nrog tib viscosity tab sis txawv fineness, nyob rau hauv tib qhov sib ntxiv, qhov finer lub finer qhov zoo dua cov dej tuav nyhuv.

Txoj kev xaiv cellulose yog dab tsi?

Teb: Tus nqi ntawm cellulose ether siv nyob rau hauv ntau daim ntawv thov yog raws li qhov xav tau ntawm cov dej tuav. Haum rau txhua yam mortar. Cov substrate absorbent heev xav tau ntau dua ntawm cellulose ether. Cov mortars nrog ib qho kev faib me me me me thiab yog li thaj tsam loj dua kuj xav tau ntau dua ntawm cellulose ether.

Cov kev hloov kho tshwj xeeb tuaj yeem xaiv rau cov kev cai tiv thaiv sagging. Yog tias qhov kev hloov kho tsis txaus, cov hmoov txhuv nplej siab ethers, feem ntau yog hydroxypropyl starch ethers, tuaj yeem ntxiv los tiv thaiv sags.

Tag nrho cov nyiaj thiab qhov loj me ntawm cov fillers nyob rau hauv formulation yuav tsum raug xaiv los muab smoothness thiab zoo sib xws.

Sib tov gypsum, muab tub lim, hom thiab kom muaj nuj nqis ntawm cellulose ether thiab siv cov hmoov txhuv nplej siab ether yuav tsum tau ua ke nrog cov hauv qab no:

Thaum cov tshuaj khib nyiab qhuav ntxiv rau qee qhov dej, cov nyiaj ntxiv yog nyob ntawm cov dej, thiab tag nrho cov dej yog soaked yam tsis tau nplawm cov hmoov qhuav nrog cov dej-rau-paste ratio. Yog tias cov khoom xyaw sib txawv sib xyaw ua ke hauv qhov tseeb, ces peb tuaj yeem tau txais ib lub mortar du nrog cov khoom siv tsim nyog tom qab sib tov.

Dab tsi yog qhov kev hloov kho ntawm lub tsev gypsum los ntawm tus neeg saib xyuas dej?

Teb: Cov ntaub ntawv phab ntsa hauv tsev feem ntau yog cov qauv ntxeem tau, thiab lawv txhua tus muaj zog nqus dej. Txawm li cas los xij, cov khoom siv hauv tsev gypsum siv rau kev tsim kho phab ntsa yog npaj los ntawm kev ntxiv dej rau ntawm phab ntsa, thiab cov dej tau yooj yim absorbed los ntawm phab ntsa, ua rau tsis muaj dej tsim nyog rau hydration ntawm gypsum, ua rau muaj teeb meem hauv plastering thiab txo. daim ntawv cog lus muaj zog, ua rau tawg, Cov teeb meem zoo xws li hollowing thiab tev. Kev txhim kho cov dej tuav ntawm gypsum cov ntaub ntawv hauv tsev tuaj yeem txhim kho kev tsim kho kom zoo thiab kev sib raug zoo nrog cov phab ntsa. Yog li ntawd, dej tuav tus neeg saib xyuas tau dhau los ua ib qho tseem ceeb ntawm cov khoom siv hauv tsev gypsum.

Feem ntau siv cov dej khaws cia hauv kuv lub tebchaws yog carboxymethyl cellulose thiab methyl cellulose. Ob tug dej tuav cov tshuaj no yog ether derivatives ntawm cellulose. Lawv txhua tus muaj cov dej num saum npoo av, thiab muaj pawg hydrophilic thiab hydrophobic hauv lawv cov molecules, uas muaj emulsification, tiv thaiv colloid thiab theem stability. Vim nws cov viscosity siab ntawm nws cov kua dej aqueous, thaum nws ntxiv rau hauv lub mortar kom muaj cov ntsiab lus dej siab, nws tuaj yeem tiv thaiv kev nqus dej ntau dhau los ntawm cov substrate (xws li cib, pob zeb, thiab lwm yam) thiab txo tus nqi evaporation. ntawm dej, yog li ua lub luag haujlwm rau kev tuav dej. Methyl cellulose yog ib qho zoo tagnrho admixture rau gypsum uas integrates dej tuav, thickening, ntxiv dag zog thiab thickening, tab sis tus nqi kuj yog siab. Feem ntau, ib tus neeg saib xyuas cov dej tsis tuaj yeem ua tiav cov txiaj ntsig zoo ntawm cov dej khaws cia, thiab kev sib xyaw ntawm cov dej sib txawv tuaj yeem tsis tsuas yog txhim kho kev siv, tab sis kuj txo cov nqi ntawm cov khoom siv gypsum.

Yuav ua li cas dej tuav cuam tshuam cov khoom ntawm gypsum composite cementitious cov ntaub ntawv?

Teb: Cov dej tuav tus nqi nce nrog qhov sib ntxiv ntawm methyl cellulose ether nyob rau hauv thaj tsam ntawm 0.05% mus rau 0.4%. Thaum tus nqi ntxiv ntxiv, qhov sib ntxiv ntawm cov dej khaws cia tau qeeb.