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 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 cov 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.
Cov khoom siv 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.
Plastering gypsum, bonded gypsum, caulking gypsum, gypsum putty thiab lwm yam khoom siv hauv tsev yog siv. Txhawm rau txhim kho kev tsim kho, gypsum retarders tau ntxiv thaum lub sijhawm tsim khoom kom ntev lub sijhawm tsim kho ntawm gypsum slurry. Vim tias gypsum yog tov nrog Retarder, uas inhibits cov txheej txheem hydration ntawm hemihydrate gypsum. Hom gypsum slurry no yuav tsum tau khaws cia rau ntawm phab ntsa rau 1 mus rau 2 teev ua ntej nws teeb. Feem ntau ntawm cov phab ntsa muaj cov khoom nqus dej, tshwj xeeb tshaj yog cov phab ntsa cib thiab cov pob zeb aerated. Phab ntsa, porous rwb thaiv tsev board thiab lwm cov ntaub ntawv tshiab ntawm cov phab ntsa, yog li kev kho dej yuav tsum tau nqa tawm ntawm gypsum slurry kom tsis txhob muaj kev hloov ntawm ib feem ntawm cov dej hauv slurry mus rau phab ntsa, ua rau dej tsis txaus thiab dej tsis tiav thaum lub gypsum. slurry yog hardened. Ua rau kev sib cais thiab tev ntawm qhov sib koom ua ke ntawm gypsum thiab phab ntsa nto. Qhov sib ntxiv ntawm cov dej tuav tus neeg sawv cev yog los tswj cov dej noo uas muaj nyob rau hauv gypsum slurry, kom ntseeg tau tias cov tshuaj tiv thaiv dej ntawm gypsum slurry ntawm qhov sib txuas, thiaj li ua kom lub zog sib txuas. Feem ntau siv cov dej tuav cov dej yog cov cellulose ethers, xws li: methyl cellulose (MC), hydroxypropyl methyl cellulose (HPMC), hydroxyethyl methyl cellulose (HEMC), thiab lwm yam. Tsis tas li ntawd, polyvinyl cawv, sodium alginate, hloov cov hmoov txhuv nplej siab, diatomaceous earth, hmoov av tsawg, thiab lwm yam kuj tuaj yeem siv los txhim kho kev tuav dej.
Tsis muaj teeb meem dab tsi ntawm cov dej tuav tus neeg saib xyuas tuaj yeem ncua qhov hydration ntawm gypsum mus rau qhov sib txawv, thaum tus nqi ntawm cov retarder tseem tsis hloov, tus neeg saib xyuas dej tuaj yeem.
feem ntau retard teeb rau 15-30 feeb. Yog li ntawd, tus nqi ntawm retarder tuaj yeem raug txo kom tsim nyog.
Post lub sij hawm: Nov-24-2022