HPMC (Hydroxypropyl Methyl Cellulose) yog cov khoom siv polymer uas feem ntau siv rau hauv cov ntaub ntawv tsim kho, tshwj xeeb tshaj yog cov ntaub ntawv ua los ntawm cement thiab gypsum. Nws muaj cov dej solubility zoo, nplaum tau zoo, khaws dej tau zoo thiab tuab, yog li nws siv dav hauv cov mortar, hmoov putty, nplaum pobzeb thiab lwm yam ntaub ntawv.
1. Ua rau cov khoom siv hauv tsev ntsws thiab tawg
Thaum lub sijhawm ua kom tawv, cov khoom siv hauv tsev feem ntau yuav ntsws vim yog dej ua pa, cov tshuaj lom neeg thiab kev hloov pauv ntawm cov yam ntxwv ib puag ncig sab nraud, ua rau muaj kev ntxhov siab thiab tawg. Cov hom kev ntsws tseem ceeb suav nrog:
Kev ntsws yas: Thaum cov khoom siv cement tseem tsis tau tawv, qhov ntim yuav ntsws vim yog dej ua pa sai.
Kev ntsws qhuav: Tom qab cov khoom tawv, nws raug rau huab cua ntev, thiab cov dej ua pa qeeb qeeb, ua rau ntim ntsws.
Kub ntsws: Kev hloov pauv ntawm qhov ntim los ntawm kev hloov pauv ntawm qhov kub thiab txias, tshwj xeeb tshaj yog nyob rau hauv ib puag ncig uas muaj qhov sib txawv ntawm qhov kub thiab txias ntawm nruab hnub thiab hmo ntuj.
Kev ntsws ntawm tus kheej: Thaum lub sijhawm ua cov cement hydration, qhov ntim sab hauv yuav ntsws vim yog kev siv dej los ntawm cov tshuaj hydration.
Cov kev ntsws no feem ntau ua rau muaj kev ntxhov siab hauv cov khoom siv, thaum kawg ua rau muaj cov kab nrib pleb me me lossis cov kab nrib pleb, uas cuam tshuam rau qhov ruaj khov thiab kev zoo nkauj ntawm cov qauv tsev. Yuav kom tsis txhob muaj qhov xwm txheej no, cov khoom ntxiv feem ntau xav tau los txhim kho kev ua tau zoo ntawm cov khoom siv, thiab HPMC yog ib qho ntawm lawv.
2. Txoj kev ua haujlwm ntawm HPMC
HPMC ua lub luag haujlwm tseem ceeb hauv kev txo qhov shrinkage thiab tawg ntawm cov ntaub ntawv hauv tsev, uas feem ntau yog ua tiav los ntawm cov txheej txheem hauv qab no:
Kev khaws dej: HPMC muaj peev xwm khaws dej tau zoo thiab tuaj yeem tsim cov zaj duab xis khaws dej hauv cov hmoov av lossis hmoov putty kom qeeb qhov kev ua kom dej noo. Vim tias qhov kev ua kom dej noo sai sai hauv cov khoom yuav ua rau cov yas ntsws, qhov cuam tshuam ntawm kev khaws dej ntawm HPMC tuaj yeem txo qhov tshwm sim ntawm kev ntsws thaum ntxov, khaws cov dej hauv cov khoom kom txaus, yog li txhawb nqa cov tshuaj tiv thaiv dej tag nrho ntawm cov cement thiab txo cov kab nrib pleb uas tshwm sim los ntawm kev poob dej thaum lub sijhawm ziab. Tsis tas li ntawd, HPMC tuaj yeem txhim kho kev ua tau zoo ntawm cov khoom hauv qab ntub thiab qhuav thiab txo qhov tawg uas tshwm sim los ntawm kev poob dej.
Cov nyhuv ua kom tuab thiab muaj zog: HPMC yog cov khoom ua kom tuab uas tuaj yeem ua rau kom cov mortar sib xws thiab viscosity zoo dua thiab txhim kho qhov sib txuas ntawm cov khoom. Thaum lub sijhawm tsim kho, yog tias cov khoom nyias dhau, nws yooj yim rau delaminate lossis sag, ua rau qhov chaw tsis sib xws lossis txawm tias tawg. Los ntawm kev siv HPMC, cov mortar tuaj yeem tswj tau qhov viscosity tsim nyog, txhim kho lub zog thiab qhov ceev ntawm cov khoom tom qab tsim kho, thiab txo qhov ua tau ntawm kev tawg. Tsis tas li ntawd, HPMC kuj tseem tuaj yeem txhim kho qhov shear tsis kam ntawm cov khoom thiab txhim kho nws qhov tsis kam tawg.
Txhim kho qhov yooj ywm ntawm cov khoom siv: HPMC molecules tuaj yeem ua lub luag haujlwm tshwj xeeb hauv kev txhim kho qhov yooj ywm hauv cov ntaub ntawv cement lossis cov ntaub ntawv gypsum, yog li cov khoom siv muaj qhov zoo dua tensile thiab khoov tsis kam tom qab kho. Txij li thaum cov ntaub ntawv tsim kho feem ntau raug rau kev ntxhov siab tensile lossis khoov nyob rau hauv qhov kub thiab txias hloov pauv thiab thauj khoom, tom qab ntxiv HPMC, qhov yooj ywm ntawm cov khoom siv nce ntxiv, uas tuaj yeem nqus tau qhov kev ntxhov siab sab nraud zoo dua thiab zam kev tawg brittle.
Tswj qhov ceev ntawm cov tshuaj tiv thaiv cement: Hauv cov ntaub ntawv ua los ntawm cement, qhov ceev ntawm qhov ceev ntawm cov tshuaj tiv thaiv hydration cuam tshuam ncaj qha rau kev ua haujlwm ntawm cov khoom siv. Yog tias qhov tshuaj tiv thaiv hydration sai dhau, qhov kev ntxhov siab hauv cov khoom siv tsis tuaj yeem tso tawm raws sijhawm, ua rau muaj kev tawg. HPMC tuaj yeem ua rau qeeb qhov ceev ntawm cov tshuaj tiv thaiv hydration los ntawm nws cov dej khaws cia thiab kev tsim cov yeeb yaj kiab tiv thaiv, tiv thaiv cov cement kom tsis txhob poob dej sai dhau thaum ntxov, thiab yog li zam qhov tshwm sim ntawm kev ntsws thiab tawg thaum lub sijhawm tawv ntawm cov khoom siv.
Txhim kho kev ua tau zoo ntawm kev tsim kho: HPMC tuaj yeem txhim kho kev ua tau zoo ntawm cov khoom siv hauv kev tsim kho, feem ntau pom tseeb hauv nws cov dej ntws zoo, kev khaws dej thiab kev nplua nuj, ua kom cov khoom sib xws, thiab txo cov kab nrib pleb los ntawm kev tsim kho tsis raug. Nws tuaj yeem ua rau cov hmoov av, hmoov putty, thiab lwm yam yooj yim dua rau kev nthuav dav thiab sib npaug thaum lub sijhawm tsim kho, txo qhov sib piv ntawm cov khoom siv, txhim kho qhov ceev thiab lub zog ntawm cov khoom siv, thiab txo qhov kev pheej hmoo ntawm kev tawg hauv zos los ntawm kev tsim kho tsis sib xws.
3. Kev siv HPMC hauv cov ntaub ntawv tsim kho tshwj xeeb
Cov nplaum rau pobzeb: HPMC tuaj yeem txhim kho qhov kev ua tau zoo ntawm cov nplaum pobzeb, xyuas kom meej tias cov pobzeb tuaj yeem sib txuas nrog lub substrate thaum lub sijhawm teeb tsa, thiab txo qhov poob lossis tawg los ntawm kev ntxhov siab tsis sib xws lossis ntsws. Tsis tas li ntawd, cov teebmeem thickening thiab khaws dej ntawm HPMC kuj tseem ua rau cov nplaum pobzeb khaws cia lub sijhawm qhib ntev dua tom qab kev tsim kho, txhim kho kev ua haujlwm ntawm kev tsim kho, thiab txo cov kab nrib pleb los ntawm kev kho tsis sib xws.
Hmoov Putty: Hauv hmoov putty, HPMC cov khoom khaws dej tuaj yeem tiv thaiv cov putty kom tsis txhob poob dej sai dhau thaum lub sijhawm ziab, thiab txo qhov ntsws thiab tawg los ntawm kev poob dej. Tib lub sijhawm, qhov cuam tshuam ntawm HPMC tuaj yeem txhim kho kev ua haujlwm ntawm putty, ua rau nws yooj yim dua los thov sib npaug ntawm phab ntsa, thiab txo cov kab nrib pleb los ntawm kev siv tsis sib xws.
Mortar: Ntxiv HPMC rau hauv mortar tuaj yeem txhim kho nws txoj kev ua haujlwm zoo, ua rau mortar du thaum lub sijhawm tsim kho, txo kev sib cais thiab stratification, thiab yog li txhim kho qhov sib xws thiab kev nplaum ntawm mortar. Tib lub sijhawm, cov dej khaws cia ntawm HPMC tuaj yeem ua rau cov dej evaporate qeeb dua thaum lub sijhawm ua kom tawv ntawm mortar, zam kev ntsws thiab tawg los ntawm kev poob dej thaum ntxov.
4. Cov kev ceev faj rau kev siv HPMC
Kev tswj cov tshuaj: Qhov ntau ntawm HPMC ntxiv muaj qhov cuam tshuam ncaj qha rau nws cov nyhuv, thiab nws feem ntau yuav tsum tau hloov kho raws li qhov sib piv ntawm cov khoom siv thiab cov xwm txheej siv tshwj xeeb. HPMC ntau dhau yuav ua rau cov khoom siv muaj qhov sib xws siab dhau, cuam tshuam rau kev ua haujlwm ntawm kev tsim kho; thaum tsis txaus HPMC yuav tsis tuaj yeem ua lub luag haujlwm ntawm kev khaws dej thiab thickening raws li nws yuav tsum tau ua.
Siv nrog lwm cov khoom ntxiv: HPMC feem ntau yog siv ua ke nrog lwm cov tshuaj ntxiv (xws li cov tshuaj txo dej, cov neeg sawv cev rau huab cua, cov khoom yas, thiab lwm yam) kom ua tiav cov txiaj ntsig zoo dua. Thaum siv, nws yog ib qho tsim nyog yuav tsum xav txog kev sib cuam tshuam ntawm cov khoom ntxiv sib txawv kom tsis txhob muaj kev cuam tshuam rau kev ua tau zoo ntawm cov ntaub ntawv.
Ua ib qho tshuaj ntxiv rau hauv tsev, HPMC muaj txiaj ntsig zoo rau kev txo qhov kev ntsws thiab kev tawg ntawm cov ntaub ntawv hauv tsev. Nws ua kom cov kab nrib pleb uas tshwm sim los ntawm kev poob dej thiab kev ntxhov siab los ntawm kev txhim kho kev khaws dej, kev tuab, kev ywj pheej ntawm cov khoom thiab kev txhim kho qhov kev ua kom cov cement hydration. Kev siv HPMC kom tsim nyog tsis yog tsuas yog txhim kho kev ua tau zoo ntawm cov khoom siv hauv tsev xwb, tab sis kuj ua rau lub neej ua haujlwm ntawm cov qauv tsev ntev dua thiab txo tus nqi ntawm kev saib xyuas tom qab. Nrog rau kev nce qib tas mus li ntawm cov thev naus laus zis hauv tsev, kev siv HPMC hauv kev tsim kho yuav dav dua thiab tob dua.
Lub sijhawm tshaj tawm: Cuaj hlis-21-2024