Viscosity yog ib qho tseem ceeb ntawm kev ua tau zoo ntawm cellulose ether.
Feem ntau hais lus, qhov viscosity siab dua, qhov zoo dua qhov cuam tshuam ntawm gypsum mortar. Txawm li cas los xij, qhov viscosity siab dua, qhov hnyav molecular ntawm cellulose ether siab dua, thiab qhov txo qis hauv nws cov solubility yuav muaj qhov cuam tshuam tsis zoo rau lub zog thiab kev ua haujlwm ntawm cov mortar. Qhov viscosity siab dua, qhov pom tseeb dua qhov cuam tshuam ntawm cov mortar tuab dua, tab sis nws tsis yog proportional ncaj qha.
Qhov siab dua qhov viscosity, qhov ntau dua cov mortar ntub yuav viscous. Thaum lub sijhawm tsim kho, nws pom tseeb tias lo rau ntawm tus scraper thiab lo rau lub substrate siab. Tab sis nws tsis pab ntau los ua kom lub zog ntawm cov mortar ntub nws tus kheej. Tsis tas li ntawd, thaum lub sijhawm tsim kho, qhov kev ua tau zoo tiv thaiv kev poob qis ntawm cov mortar ntub 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 heev hauv kev txhim kho lub zog ntawm cov mortar ntub.
Cov ntaub ntawv phab ntsa tsev feem ntau yog cov qauv porous, thiab lawv txhua tus muaj zog nqus dej. Txawm li cas los xij, cov ntaub ntawv gypsum siv rau kev tsim phab ntsa yog npaj los ntawm kev ntxiv dej rau ntawm phab ntsa, thiab dej yooj yim nqus los ntawm phab ntsa, ua rau tsis muaj dej tsim nyog rau kev ua kom gypsum noo, ua rau muaj teeb meem hauv kev tsim kho plastering thiab txo qis lub zog sib txuas, ua rau muaj kab nrib pleb, teeb meem zoo xws li hollowing thiab tev tawm. Kev txhim kho kev khaws dej ntawm cov ntaub ntawv tsev gypsum tuaj yeem txhim kho qhov zoo ntawm kev tsim kho thiab lub zog sib txuas nrog phab ntsa. Yog li ntawd, tus neeg sawv cev khaws dej tau dhau los ua ib qho ntawm cov khoom sib xyaw tseem ceeb ntawm cov ntaub ntawv tsev gypsum.
Siv cov tshuaj gypsum ua ke, cov tshuaj gypsum sib txuas, cov tshuaj caulking gypsum, cov tshuaj gypsum putty thiab lwm yam khoom siv hmoov ua vaj tse. Yuav kom yooj yim rau kev tsim kho, cov tshuaj gypsum retarders raug ntxiv thaum lub sijhawm tsim khoom kom ntev lub sijhawm tsim kho ntawm gypsum slurry. Vim tias gypsum sib xyaw nrog Retarder, uas tiv thaiv cov txheej txheem hydration ntawm hemihydrate gypsum. Hom gypsum slurry no yuav tsum tau khaws cia rau ntawm phab ntsa rau 1 ~ 2 teev ua ntej nws teeb. Feem ntau ntawm cov phab ntsa muaj cov yam ntxwv nqus dej, tshwj xeeb tshaj yog cov phab ntsa cib thiab cov pob zeb aerated. Phab ntsa, cov laug cam rwb thaiv tsev thiab lwm yam khoom siv phab ntsa tshiab sib dua, yog li kev kho dej khaws cia yuav tsum tau ua rau ntawm gypsum slurry kom tsis txhob muaj kev hloov pauv ntawm ib feem ntawm cov dej hauv slurry mus rau phab ntsa, ua rau dej tsis txaus thiab tsis muaj dej txaus thaum gypsum slurry tawv. Ua rau muaj kev sib cais thiab tev ntawm qhov sib koom ua ke ntawm gypsum thiab phab ntsa. Kev ntxiv cov neeg sawv cev khaws dej yog kom tswj tau cov dej noo uas muaj nyob hauv gypsum slurry, kom ntseeg tau tias cov tshuaj hydration ntawm gypsum slurry ntawm qhov sib tshuam, kom ntseeg tau tias muaj zog sib txuas. Cov tshuaj uas siv los khaws dej feem ntau yog 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, hmoov txhuv nplej siab hloov kho, diatomaceous av, hmoov av tsis tshua muaj, thiab lwm yam kuj siv tau los txhim kho kev ua haujlwm khaws dej.
Txawm yog hom tshuaj twg uas tuav dej tau los ncua qhov dej ntawm gypsum mus rau ntau qib sib txawv, thaum cov tshuaj retarder tseem tsis hloov pauv, feem ntau cov tshuaj retarder tuaj yeem ncua qhov chaw teeb tsa rau 15-30 feeb. Yog li ntawd, qhov ntau ntawm retarder tuaj yeem txo tau kom haum.
Lub sijhawm tshaj tawm: Lub Ob Hlis-08-2023