Hydroxypropyl Methylcellulose (HPMC) yog ib qho tseem ceeb ntawm cellulose ether uas tau siv dav hauv cov tshuaj khib nyiab qhuav los txhim kho nws cov kev tsim kho. Lub mechanism ntawm kev txiav txim ntawm HPMC nyob rau hauv qhuav-siv mortar yog feem ntau xav txog nyob rau hauv noo noo retention, sib xws hloov, sag kuj thiab cracking kuj.
1. Kev khaws dej noo
Lub luag haujlwm tseem ceeb ntawm HPMC yog txhawm rau txhim kho lub peev xwm khaws dej ntawm cov tshuaj khib nyiab qhuav. Thaum lub sij hawm tsim kho, qhov ceev ceev evaporation ntawm cov dej nyob rau hauv lub mortar yuav ua rau nws qhuav sai heev, ua rau tsis tiav hydration ntawm cov cement thiab cuam tshuam rau lub zog kawg. Cov qauv molecular ntawm HPMC muaj ntau pawg hydrophilic (xws li hydroxyl thiab methoxy pawg), uas tuaj yeem tsim cov hydrogen bonds thiab txhim kho cov dej tuav tau zoo. Lub network qauv nws tsim nyob rau hauv lub mortar pab xauv nyob rau hauv noo noo, yog li slowing down tus nqi ntawm cov dej evaporation.
Kev tuav dej tsis yog tsuas yog pab txuas ntxiv lub sijhawm ua haujlwm ntawm mortar, tab sis kuj tseem txhim kho qhov smoothness ntawm kev tsim kho nyob rau hauv qis kub los yog qhuav ib puag ncig. Los ntawm kev tswj hwm cov av noo txaus, HPMC ua rau lub mortar kom muaj kev ua haujlwm zoo nyob rau lub sijhawm ntev, tsis txhob tawg thiab tsim teeb meem tshwm sim los ntawm kev poob dej.
2. Kev kho kom haum
HPMC kuj muaj kev ua haujlwm ntawm kev kho qhov sib xws ntawm cov khoom sib xyaw qhuav, uas yog qhov tseem ceeb rau cov dej ntws thiab kev nthuav dav ntawm kev tsim kho. HPMC tsim cov tshuaj colloidal thaum yaj hauv dej, thiab nws cov viscosity nce nrog qhov hnyav molecular. Thaum lub sij hawm tsim kho, cov khoom colloidal ntawm HPMC khaws cov mortar ntawm ib qho kev sib xws thiab zam kom tsis txhob muaj qhov dej ntawm cov tshuaj khib nyiab vim muaj kev sib cais ntawm cov dej noo.
Kev sib raug zoo kom ntseeg tau tias cov tshuaj khib yog sib npaug ntawm cov substrate thiab tuaj yeem ua kom cov pores thiab qhov tsis sib xws ntawm qhov chaw ntawm lub substrate. Cov yam ntxwv no tseem ceeb heev los xyuas kom meej qhov adhesion thiab kev tsim kho zoo ntawm mortar. HPMC kuj tuaj yeem hloov kho rau qhov kev xav tau sib txawv los ntawm kev kho qhov sib txawv thiab muab kev tswj tau zoo.
3. Anti-sag khoom
Nyob rau hauv ntsug los yog inclined siv qhov chaw (xws li phab ntsa plastering los yog masonry bonding), lub mortar yog nquag sagging los yog zawv zawg vim nws qhov hnyav. HPMC txhim kho lub sag tsis kam ntawm mortar los ntawm kev nce nws cov thixotropy. Thixotropy hais txog lub peev xwm ntawm mortar kom txo nws cov viscosity thaum raug shear quab yuam thiab rov qab nws viscosity tom qab lub shear quab yuam ploj. HPMC tuaj yeem tsim cov slurry nrog cov thixotropy zoo, ua rau cov mortar yooj yim rau kev siv thaum lub sij hawm tsim kho, tab sis nws muaj peev xwm rov qab tau nws cov viscosity sai thiab raug kho rau ntawm qhov chaw tsim kho tom qab tso tseg kev ua haujlwm.
Cov yeeb yam no txo qis cov khib nyiab pov tseg thiab txhim kho kev tsim kho kom zoo thiab zoo. Hauv cov ntawv thov xws li cov pobzeb sib txuas, HPMC lub sag kuj tuaj yeem ua kom cov vuas tsis txav tom qab tau muab tso, yog li txhim kho qhov raug.
4. Cracking kuj
Cov mortar qhuav sib xyaw tom qab kev tsim kho yog nquag tawg thaum lub sij hawm hardening txheej txheem, uas yog feem ntau tshwm sim los ntawm shrinkage los ntawm uneven tis ntawm internal ya raws. Los ntawm kev txhim kho cov dej tuav thiab qhov sib xws ntawm cov tshuaj khib nyiab, HPMC tuaj yeem txo cov dej noo hauv cov gradients, yog li txo qis kev ntxhov siab. Nyob rau tib lub sijhawm, HPMC tuaj yeem cuam tshuam thiab nqus kev ntxhov siab thiab txo qhov tshwm sim ntawm kev tawg los ntawm kev tsim cov qauv sib txuas sib txuas hauv mortar.
Kev tiv thaiv kev tawg yog qhov tseem ceeb rau kev ua kom cov kav ntev thiab kev pab cuam lub neej ntawm mortar. Qhov kev ua haujlwm ntawm HPMC ua rau cov tshuaj khib kom muaj lub cev zoo thaum siv mus ntev thiab tsis tshua muaj kev tawg thiab tev.
5. Kev tsim kho rooj plaub thiab daim ntawv thov
Hauv kev tsim kho tiag tiag, HPMC feem ntau yog ntxiv rau ntau hom qhuav sib xyaw mortars raws li cov kev xav tau tshwj xeeb, xws li plastering mortars, pobzeb bonding mortars thiab self-leveling mortars. Qhov tshwj xeeb ntxiv thiab qhov kev faib ua feem yuav tsum tau ua kom zoo raws li hom mortar, qhov xwm txheej ntawm cov khoom siv hauv paus thiab qhov chaw tsim kho. Piv txwv li, thaum tsim kho nyob rau hauv ib puag ncig kub, tsim nyog nce tus nqi ntawm HPMC tuaj yeem txhim kho cov dej tuav ntawm cov tshuaj khib nyiab thiab zam kev tsim teeb meem thiab teeb meem zoo los ntawm kev ziab sai.
Nyob rau hauv daim ntawv thov ntawm ceramic pobzeb adhesives, HPMC muaj peev xwm muab tau zoo heev adhesion thiab sag kuj los xyuas kom meej lub ruaj adhesion ntawm ceramic vuas rau phab ntsa. Nyob rau tib lub sijhawm, los ntawm kev kho tus nqi ntawm HPMC ntxiv, lub sijhawm qhib mortar kuj tuaj yeem tswj tau los pab txhawb kev ua haujlwm ntawm cov neeg ua haujlwm tsim kho.
Hydroxypropyl methylcellulose (HPMC), raws li cov khoom siv tau zoo, txhim kho kev tsim kho ntawm cov tshuaj khib nyiab qhuav los ntawm nws cov dej tuav, kev hloov kho sib xws, tiv thaiv sag thiab tiv thaiv kev tawg. Cov khoom no tsis tsuas yog txhim kho kev tuav cov khoom ntawm lub mortar, tab sis kuj txhim kho kev tsim kho kom zoo thiab kav ntev. Daim ntawv thov tsim nyog ntawm HPMC tuaj yeem tiv taus cov kev cov nyom ntawm ntau qhov chaw tsim kho thiab muab cov khoom siv zoo dua rau kev tsim kho. Nyob rau hauv lub neej yav tom ntej, nrog kev txhim kho txuas ntxiv ntawm cov ntaub ntawv tshawb fawb thiab kev tsim kho thev naus laus zis, daim ntawv thov kev cia siab ntawm HPMC hauv cov tshuaj khib nyiab qhuav yuav dav dua.
Post lub sij hawm: Lub Xya hli ntuj-10-2024