Hydroxypropyl Methylcellulose (HPMC) plays lub luag haujlwm tseem ceeb hauv cov khoom sib xyaw qhuav-sib xyaw ua ke. Qhuav mix npaj-mixed mortar yog cov khoom siv hmoov qhuav ua los ntawm kev sib xyaw ua ke, cement, fillers thiab ntau yam additives hauv ib qho kev faib ua feem. Nws tuaj yeem siv rau ntawm qhov chaw tsim kho los ntawm kev ntxiv dej thiab nplawm. Raws li cov cellulose ether ua tau zoo heev, HPMC plays ntau lub luag haujlwm hauv cov khoom sib xyaw qhuav sib xyaw ua ke, yog li txhim kho kev ua haujlwm ntawm cov mortars.
1. Kev tuav dej
Lub luag haujlwm tseem ceeb ntawm HPMC yog txhawm rau txhim kho cov dej tuav ntawm mortar. Txij li thaum cellulose molecules muaj ntau pawg hydroxyl thiab methoxy, lawv tuaj yeem tsim hydrogen bonds nrog dej molecules, yog li txhim kho cov dej tuav lub peev xwm ntawm cov tshuaj khib nyiab. Kev tuav dej zoo tso cai rau cov dej noo hauv cov mortar kom khaws cia ntawm cov evaporation sai rau lub sijhawm ntev, uas yog qhov tseem ceeb rau kev ncua lub sijhawm qhib, txhim kho kev tsim kho, txo cov kab nrib pleb thiab txhim kho lub zog ntawm cov mortar. Tshwj xeeb tshaj yog nyob rau hauv kev tsim kho ntawm high-temperature los yog low-water-absorbent substrates, cov dej tuav nyhuv ntawm HPMC yog pom tseeb dua.
2. Txhim kho kev tsim kho kev ua haujlwm
HPMC muab cov mortar zoo heev tsim khoom. Ua ntej, nws txhim kho kev ua haujlwm ntawm cov tshuaj khib nyiab, ua rau cov tshuaj khib nyiab sib xyaw ntau dua thiab zoo. Qhov thib ob, HPMC txhim kho cov thixotropy ntawm mortar, uas yog, cov tshuaj khib nyiab tuaj yeem tswj tau qhov sib xws thaum nyob ruaj ruaj, tab sis ntws yooj yim hauv kev ntxhov siab. Cov yam ntxwv no ua rau cov mortar muaj kev ua haujlwm zoo thiab siv tau thaum lub sijhawm tsim kho, thiab yooj yim rau kev thov thiab du. Tsis tas li ntawd, HPMC tuaj yeem txo qhov adhesion ntawm mortar thaum lub sij hawm tsim kho, ua kom cov cuab yeej siv tau yooj yim los ntxuav.
3. Anti-sag khoom
Thaum lub sij hawm tsim kho ntawm qhov chaw ntsug, mortar nyiam sag vim lub ntiajteb txawj nqus, cuam tshuam rau kev tsim kho kom zoo. HPMC tuaj yeem txhim kho qhov sag tsis kam ntawm mortar, tso cai rau cov mortar kom zoo dua rau ntawm qhov chaw ntawm lub substrate thaum ntxov tom qab kev tsim kho thiab tsis txhob sagging. Qhov no yog qhov tseem ceeb tshwj xeeb rau cov ntaub ntawv xws li cov pobzeb nplaum thiab plaster mortars uas yuav tsum tau siv rau qhov chaw ntsug.
4. Txhim kho plasticity tuav
HPMC tuaj yeem txhim kho cov yas khaws cia ntawm cov tshuaj khib nyiab, ua rau nws tsis tshua muaj qis thiab tawg thaum lub sijhawm kho. Nws cov txheej txheem yog tsuas yog ua kom cov dej noo nyob rau hauv mortar los ntawm kev txhim kho microstructure ntawm mortar, yog li txo cov evaporation tus nqi ntawm cov dej. Tsis tas li ntawd, HPMC kuj tseem tuaj yeem tsim cov qauv hauv kev sib txuas hauv cov tshuaj khib nyiab, txhim kho lub zog tensile thiab hloov tau yooj yim ntawm mortar, thiab txo cov kab nrib pleb los ntawm shrinkage ntawm mortar thaum lub sij hawm hardening txheej txheem.
5. Txhim kho kev sib raug zoo
HPMC tuaj yeem txhim kho kev sib raug zoo ntawm mortar. Qhov no feem ntau yog los ntawm cov pawg polar uas muaj nyob rau hauv nws cov qauv molecular, uas tuaj yeem ua rau lub cev adsorb nrog cov molecules ntawm qhov chaw ntawm lub substrate thiab txhim kho lub zog sib txuas ntawm cov mortar thiab substrate. Nyob rau tib lub sijhawm, cov dej tuav tau los ntawm HPMC kuj tseem pab cov cement hydration cov tshuaj tiv thaiv kom ua tiav tag nrho, yog li ntxiv kev txhim kho kev sib txuas ntawm cov mortar.
6. Kho mortar sib xws
HPMC kuj tuaj yeem kho qhov sib xws ntawm cov mortar kom cov mortar ua kom muaj dej txaus thiab ua haujlwm tau zoo tom qab ntxiv dej. HPMC nrog cov viscosities sib txawv tuaj yeem siv ntau hom mortars. Kev xaiv cov khoom tsim nyog raws li qhov xav tau tiag tiag tuaj yeem ua rau lub mortar yooj yim rau kev tswj thiab siv thaum siv.
7. Txhim khu kev ruaj ntseg mortar
HPMC tuaj yeem txhim kho kev ruaj ntseg ntawm mortar thiab txo kev sib cais ntawm mortar thaum sib xyaw thiab kev thauj mus los. Vim nws cov nyhuv thickening siab, nws muaj peev xwm stabilize cov khoom hais nyob rau hauv lub mortar, tiv thaiv kev sib hais haum thiab delamination, thiab khaws cov mortar nyob rau hauv ib tug uniform lub xeev thaum lub sij hawm tsim kho.
8. Huab cua tsis kam
Qhov sib ntxiv ntawm HPMC tuaj yeem txhim kho huab cua tsis kam ntawm mortar, tshwj xeeb tshaj yog nyob rau hauv huab cua huab cua. Nws tuaj yeem txo qhov kev ntxhov siab los ntawm qhov kub thiab txias ntawm cov mortar, yog li txhim kho cov kav ntev thiab kev pab cuam lub neej ntawm mortar.
Raws li ib qho tseem ceeb additive, hydroxypropyl methylcellulose tau zoo heev txhim kho cov qhuav-mix npaj cov khoom los ntawm nws cov dej tuav zoo, kev tsim kho kev ua tau zoo, sag tsis kam, txhim kho plasticity tuav thiab kev sib txuas lub zog. Kev ua tau zoo thiab kev tsim kho ntawm kev sib xyaw mortar. Nws daim ntawv thov tuaj yeem tsis tsuas yog txhim kho lub cev lub cev ntawm mortar, tab sis kuj txhim kho kev tsim kho thiab txo kev tsim kho nyuaj, yog li siv dav hauv kev tsim kho.
Lub sij hawm xa tuaj: Plaub Hlis-04-2024