HPMC (Hydroxypropyl Methylcellulose) yog ib qho khoom siv ntxiv uas feem ntau siv rau hauv kev tsim kho plaster, tshwj xeeb tshaj yog hauv kev txhim kho kev tiv thaiv dej, rheological zog thiab kev ua tau zoo ntawm kev tsim kho plaster.
1. Txhim kho qhov dej khaws cia ntawm plaster
HPMC yog ib qho tshuaj polymer uas yaj tau hauv dej uas tuaj yeem tsim cov qauv network hauv cov cement lossis gypsum-based plaster. Cov qauv no pab khaws dej thiab tiv thaiv cov cement lossis gypsum kom tsis txhob poob dej sai dhau thaum lub sijhawm ua kom tawv, yog li ntawd zam kev tawg lossis txo qhov tsis kam dej. Los ntawm kev ntxiv HPMC kom raug rau hauv plaster, cov txheej txheem hydration ntawm cement tuaj yeem ncua sijhawm, ua rau cov plaster muaj peev xwm zoo dua los khaws dej. Cov hydrate tsim los ntawm cement thaum lub sijhawm ua kom hydration xav tau dej txaus los txhawb kev tshuaj tiv thaiv. Kev ncua sijhawm poob dej tuaj yeem txhim kho qhov ceev thiab tiv thaiv kev nkag mus ntawm cov khoom kawg.
2. Txhim kho qhov adhesion thiab ceev ntawm plaster
Ua ib qho tshuaj ntxiv polymer, HPMC tsis yog tsuas yog txhim kho cov khoom rheological ntawm plaster, tab sis kuj txhim kho nws cov adhesion. Thaum ntxiv HPMC, lub zog sib txuas ntawm plaster yog txhim kho, uas pab nws tsim kom muaj kev sib txuas zoo dua rau lub substrate (xws li cib, pob zeb lossis phab ntsa gypsum). Tib lub sijhawm, HPMC ua rau plaster tsim cov qauv denser thaum lub sijhawm hardening, txo qhov muaj cov capillary pores. Cov pores tsawg dua txhais tau tias nws nyuaj rau dej nkag mus, yog li txhim kho cov dej tsis kam ntawm plaster.
3. Kev tiv thaiv permeability zoo dua
Cov qauv molecular ntawm HPMC tuaj yeem tsim cov khoom zoo li colloid hauv cov plaster, uas ua rau cov plaster tsim cov qauv microstructure sib xws thaum lub sijhawm kho. Thaum cov qauv zoo dua, qhov chaw ntawm plaster yuav du thiab ntom dua, thiab qhov permeability ntawm dej txo qis. Yog li ntawd, qhov tsis kam ntawm cov dej ntawm cov plaster tau zoo dua, tshwj xeeb tshaj yog nyob rau hauv cov chaw noo noo lossis dej ntau, kev ntxiv HPMC tuaj yeem tiv thaiv cov dej noo kom tsis txhob nkag mus rau hauv phab ntsa los ntawm cov txheej plaster.
4. Txhim kho kev ruaj khov thiab kev tiv thaiv dej
Kev tiv thaiv dej tsis yog tsuas yog nyob ntawm qhov muaj peev xwm tiv thaiv dej ntawm cov khoom siv xwb, tab sis kuj muaj feem cuam tshuam nrog cov qauv sab hauv ntawm lub plaster. Los ntawm kev ntxiv HPMC, kev ruaj khov ntawm lub cev thiab tshuaj lom neeg ntawm lub plaster tuaj yeem txhim kho. HPMC txhim kho kev tiv thaiv tshuaj lom neeg ntawm plaster thiab zam kev xeb cement los ntawm dej nkag mus. Tshwj xeeb tshaj yog nyob rau hauv lub sijhawm ntev dej lossis qhov chaw noo noo, HPMC pab txuas lub neej kev pabcuam ntawm plaster thiab txhim kho nws cov khoom tiv thaiv kev laus.
5. Kho qhov viscosity thiab workability
HPMC kuj muaj lub luag haujlwm ntawm kev kho qhov viscosity thiab rheological properties. Hauv kev tsim kho tiag tiag, qhov viscosity tsim nyog tuaj yeem ua rau cov plaster tsis yooj yim ntws thaum siv, thiab tuaj yeem npog sib npaug ntawm phab ntsa yam tsis ua rau cov plaster poob thaum lub sijhawm tsim kho vim muaj dej ntau dhau. Los ntawm kev tswj qhov ua haujlwm ntawm cov plaster, cov neeg ua haujlwm hauv kev tsim kho tuaj yeem tswj tau qhov sib xws ntawm cov plaster zoo dua, yog li ntawd txhim kho qhov kev ua haujlwm tsis muaj dej ntawm cov plaster.
6. Txhim kho qhov tawg tsis kam
Thaum lub sijhawm tsim kho, cov plaster feem ntau yuav ntsws vim muaj tej yam sab nraud xws li qhov kub thiab txias hloov pauv thiab av noo hloov pauv, ua rau muaj kab nrib pleb. Qhov muaj kab nrib pleb tsis yog tsuas yog cuam tshuam rau qhov tsos ntawm cov plaster xwb, tab sis kuj muab ib txoj hauv kev rau dej nkag mus. Kev ntxiv HPMC tuaj yeem ua rau cov plaster tawv dua, ua rau nws muaj zog tiv thaiv kab nrib pleb thaum lub sijhawm ziab, yog li ntawd tiv thaiv cov dej noo nkag mus rau sab hauv los ntawm kab nrib pleb thiab txo qhov kev pheej hmoo ntawm dej nkag mus.
7. Txhim kho kev hloov pauv thiab kev yooj yim ntawm kev tsim kho
Qhov ntxiv ntawm HPMC kuj tseem tuaj yeem ua rau plaster hloov tau yooj yim dua nyob rau hauv ntau yam huab cua sib txawv. Hauv qhov chaw kub siab, cov dej noo ntawm plaster evaporates sai dhau thiab yooj yim tawg. Qhov muaj HPMC pab plaster khaws dej hauv qhov chaw qhuav, yog li nws qhov ceev kho tau tswj tau thiab cov kab nrib pleb thiab cov txheej tsis muaj dej puas tsuaj los ntawm kev qhuav sai dhau raug zam. Tsis tas li ntawd, HPMC kuj tseem tuaj yeem txhim kho qhov lo rau ntawm plaster, yog li nws tuaj yeem tswj tau qhov lo zoo ntawm ntau qhov chaw sib txawv thiab tsis yooj yim poob tawm.
HPMC ua lub luag haujlwm tseem ceeb hauv kev txhim kho cov dej tsis kam ntawm plaster, feem ntau yog los ntawm cov hauv qab no:
Kev khaws dej: ncua kev ua kom cov cement noo, khaws cov dej noo, thiab tiv thaiv kom qhuav sai dhau.
Kev nplaum thiab qhov ceev: txhim kho qhov nplaum ntawm plaster rau qhov chaw hauv paus thiab tsim cov qauv ntom ntom.
Kev tiv thaiv permeability: txo cov qhov hws thiab tiv thaiv dej nkag mus.
Kev ruaj khov thiab tsis muaj dej nkag: txhim kho kev ruaj khov ntawm cov tshuaj lom neeg thiab lub cev ntawm cov khoom siv thiab txuas ntxiv lub neej ua haujlwm.
Kev tiv thaiv kab nrib pleb: ua kom lub plaster tawv thiab txo qhov tsim ntawm kab nrib pleb.
Kev yooj yim ntawm kev tsim kho: Txhim kho cov khoom rheological ntawm plaster thiab txhim kho kev ua haujlwm thaum lub sijhawm tsim kho. Yog li ntawd, HPMC tsis yog tsuas yog ib qho khoom ntxiv los txhim kho kev ua haujlwm ntawm plaster, tab sis kuj txhim kho qhov tsis kam dej ntawm plaster los ntawm ntau txoj hauv kev, yog li ntawd plaster tuaj yeem tswj tau qhov ruaj khov zoo thiab lub neej ntev hauv ntau qhov chaw nyuaj.
Lub sijhawm tshaj tawm: Kaum Ib Hlis-20-2024