HPMC (hydroxypropyl methylcellulose) yog cov khoom siv ntau yam khoom siv polymer siv dav hauv cov khoom siv hauv tsev, tshwj xeeb tshaj yog cov khoom siv cement. Kev taw qhia ntawm HPMC tuaj yeem txhim kho kev ua tau zoo ntawm cov khoom siv cement-based, nrog rau kev txhim kho cov kab nrib pleb, txhim kho kev ua haujlwm thiab tswj cov txheej txheem hydration, yog li txo qhov tshwm sim ntawm kev tawg.
Cov khoom siv tshuaj thiab lub cev ntawm HPMC
HPMC yog ib tug semi-synthetic polymer chemically hloov los ntawm cellulose. Nws cov qauv molecular muaj xws li methyl thiab hydroxypropyl substituents, muab nws tshwj xeeb solubility, thickening, dej tuav thiab zaj duab xis-tsim zog. Nws cov yam ntxwv tseem ceeb suav nrog:
Kev tuav dej siab: HPMC muaj peev xwm tuav tau dej zoo heev thiab tuaj yeem tsim cov yeeb yaj kiab khaws dej hauv cov khoom kom qeeb cov dej ntws tawm.
Thickening nyhuv: HPMC tuaj yeem ua kom cov viscosity ntawm cov slurry nce, yog li txhim kho nws txoj haujlwm.
Zaj duab xis-tsim cov khoom: Nws muaj peev xwm ua yeeb yaj kiab zoo tuaj yeem tsim cov yeeb yaj kiab hloov pauv ntawm cov khoom siv, muab kev tiv thaiv lub cev ntxiv.
Kev cuam tshuam ntawm HPMC ntawm kev tawg ntawm cov khoom siv cement
1. Kev tuav dej thiab txo cov kab nrib pleb qhuav
Cementitious cov ntaub ntawv muaj kev cuam tshuam loj heev thaum lub sij hawm hardening, feem ntau yog vim dej poob thiab qhuav shrinkage vim hydration tshua. Qhuav shrinkage tej kab nrib pleb feem ntau yog tshwm sim los ntawm ceev ceev evaporation ntawm cov dej nyob rau hauv cov cement slurry thaum lub sij hawm hardening txheej txheem, ua rau lub ntim tsis sib xws, yog li ua rau tawg. Cov khoom tuav dej ntawm HPMC ua lub luag haujlwm tseem ceeb hauv qhov no:
Ua kom cov dej evaporation qeeb: HPMC khaws cov dej noo hauv cov cement slurry, yog li ua kom cov dej evaporation qeeb. Cov dej tuav cov nyhuv no tsis tsuas yog pab kom ncua sij hawm cov tshuaj tiv thaiv hydration, tab sis kuj txo qhov ziab kom qhuav los ntawm dej evaporation.
Cov tshuaj tiv thaiv dej tsis sib xws: Txij li HPMC muab ib puag ncig dej ruaj khov, cov khoom cement tuaj yeem ua rau muaj kev sib txuam ntau dua thiab muaj dej txaus txaus, txo cov kev ntxhov siab sab hauv thiab txo qhov kev pheej hmoo ntawm kev tawg los ntawm qhuav shrinkage.
2. Txhim kho cov viscosity thiab faib cov khoom sib xws
HPMC muaj cov nyhuv thickening, uas ua lub luag haujlwm tseem ceeb hauv kev txhim kho kev ua haujlwm thiab kev sib txuam ntawm cov khoom siv cement:
Ntxiv Viscosity: HPMC ua kom cov viscosity ntawm slurry, txhim kho kev ua haujlwm thaum lub sij hawm thov, cia cov slurry ntws zoo dua thiab sau cov pwm los yog cov kab nrib pleb, txo cov voids thiab tsis sib xws.
Kev faib tawm tsis sib xws: Los ntawm kev ua kom cov viscosity ntawm slurry, HPMC ua rau kev faib cov fillers thiab fibers hauv slurry ntau dua, uas ua rau cov qauv hauv cov txheej txheem tsis sib xws thaum lub sij hawm hardening txheej txheem thiab txo qhov tawg vim kev nyuaj siab hauv cheeb tsam.
3. Txhim kho zaj duab xis-tsim cov khoom thiab tiv thaiv nto
Cov khoom ua yeeb yaj kiab ntawm HPMC pab tsim cov txheej txheem tiv thaiv ntawm cov khoom siv, uas muaj txiaj ntsig zoo ntawm kev txo cov kab nrib pleb:
Kev tiv thaiv nto: Cov txheej txheej zaj duab xis hloov tau tsim los ntawm HPMC ntawm cov khoom siv tuaj yeem tiv thaiv qhov chaw los ntawm kev yaig los ntawm ib puag ncig sab nraud thiab kev poob dej sai, yog li txo qhov tshwm sim ntawm cov kab nrib pleb.
Flexible coverage: Cov txheej zaj duab xis no muaj qee qhov kev hloov pauv tau yooj yim thiab tuaj yeem nqus tau ib feem ntawm cov kev ntxhov siab thaum lub sij hawm me ntsis deformation, yog li tiv thaiv los yog qeeb ntawm kev nthuav dav ntawm cov kab nrib pleb.
4. Tswj cov txheej txheem hydration
HPMC tuaj yeem tswj cov txheej txheem dej ntawm cov cement, uas ua lub luag haujlwm tseem ceeb hauv kev txo cov kev ntxhov siab vim los ntawm cov dej tsis sib xws:
Kev tso dej qeeb qeeb: HPMC tuaj yeem txo cov tshuaj tiv thaiv dej sai sai, tso cai rau cov dej hauv cov cement slurry maj mam tso tawm, yog li muab cov dej sib xyaw ua ke ntau dua thiab muaj dej txaus. Qhov kev tso tawm qeeb qeeb no txo cov kev ntxhov siab vim los ntawm cov dej tsis sib xws, yog li txo qhov kev pheej hmoo ntawm kev tawg.
Daim ntawv thov piv txwv ntawm HPMC hauv cov khoom siv cement sib txawv
HPMC tau siv dav hauv cov khoom siv cement, suav nrog tab sis tsis txwv rau cov txheej txheem ntawm tus kheej, txheej txheej phab ntsa sab nrauv, mortars thiab cov khoom siv kho vaj tse. Cov hauv qab no yog qee qhov piv txwv ntawm kev thov tshwj xeeb:
1. Self-leveling cov ntaub ntawv hauv pem teb
Self-leveling pem teb cov ntaub ntawv yuav tsum tau zoo fluidity thiab bonding zog thaum tsis txhob nto tawg. HPMC txhim kho qhov ntws thiab nto tiav ntawm cov khoom los ntawm nws cov thickening thiab dej tuav cov teebmeem thaum txo qhov tshwm sim ntawm qhov tawg.
2. Sab nrauv phab ntsa xim
Sab nrauv xim yuav tsum tau zoo adhesion thiab tawg kuj. Cov yeeb yaj kiab tsim cov khoom thiab cov dej tuav ntawm HPMC txhim kho cov txheej txheej adhesion thiab yoog raws, yog li txhim kho cov txheej txheej tiv thaiv tawg thiab huab cua.
3. Kho cov ntaub ntawv
Cov khoom siv kho vaj tse yuav tsum muaj lub zog siab thiab ua kom tawv tawv sai thaum tswj xyuas qis qis qis. HPMC muab cov dej tuav tau zoo thiab muaj peev xwm tswj tau dej, tso cai rau cov khoom siv kho kom tsis txhob qhuav qhuav thaum lub sij hawm hardening txheej txheem thiab txo qhov kev pheej hmoo ntawm kev tawg tom qab kho.
Kev ceev faj rau kev siv HPMC
Txawm hais tias HPMC muaj cov txiaj ntsig tseem ceeb hauv kev txo qis kev tawg ntawm cov khoom siv cement, cov ntsiab lus hauv qab no tseem yuav tsum tau sau tseg thaum siv:
Kev tswj kom ntau npaum li cas: Cov koob tshuaj ntawm HPMC yuav tsum nruj me ntsis raws li cov qauv kev cai. Ntau dhau los yog tsawg dhau yuav cuam tshuam cov khoom siv. Feem ntau hais lus, qhov ntau npaum li cas ntawm 0.1% - 0.5%.
Mixing Uniformity: HPMC yuav tsum tau muab sib xyaw nrog lwm cov ntaub ntawv kom ntseeg tau tias nws ua haujlwm thoob plaws hauv slurry.
Kev tsim kho: Ib puag ncig kev tsim kho (xws li kub, av noo) kuj muaj feem cuam tshuam rau HPMC, thiab yuav tsum tau kho kom haum raws li cov xwm txheej tshwj xeeb.
Raws li cov khoom siv cement-based additive, HPMC plays lub luag haujlwm tseem ceeb hauv kev txo qhov tawg ntawm cov ntaub ntawv cement-based los ntawm nws qhov tshwj xeeb tuav dej, thickening, film-forming thiab hydration tswj zog. Nws ncua dej evaporation, txhim kho cov khoom sib xws, tiv thaiv cov khoom siv, thiab tswj cov txheej txheem hydration, yog li txo qhov kev pheej hmoo ntawm kev tawg. Yog li ntawd, nyob rau hauv daim ntawv thov ntawm cement-based cov ntaub ntawv, kev siv ntawm HPMC tsis tuaj yeem tsuas yog txhim kho cov khoom siv, tab sis kuj txuas nws lub neej kev pab cuam thiab txo cov nqi kho.
Post lub sij hawm: Jun-26-2024