HPMC (Hydroxypropyl Methyl Cellulose) ndi zinthu za polima zomwe zimagwiritsidwa ntchito kwambiri pomanga, makamaka muzinthu zopangira simenti ndi gypsum. Ili ndi kusungunuka kwamadzi bwino, kumamatira, kusunga madzi ndi kukhuthala, kotero imagwiritsidwa ntchito kwambiri mumatope, putty powder, zomatira matailosi ndi zipangizo zina.
1. Zomwe zimayambitsa kuchepa komanso kusweka kwa zida zomangira
Panthawi yowumitsa, zipangizo zomangira nthawi zambiri zimachepa chifukwa cha kutuluka kwa madzi, kusintha kwa mankhwala ndi kusintha kwa zinthu zakunja za chilengedwe, zomwe zimayambitsa kupsinjika maganizo ndi kupanga ming'alu. Mitundu yayikulu ya shrinkage ndi:
Pulasitiki shrinkage: Pamene zinthu za simenti sizinali zolimba, voliyumu imachepa chifukwa cha kutuluka kwa nthunzi mofulumira kwa madzi.
Kuphwera kouma: Zinthu zikaumitsa, zimapita kumlengalenga kwa nthawi yayitali, ndipo madzi amatuluka pang'onopang'ono, zomwe zimapangitsa kuti voliyumu ikhale yochepa.
Kutsika kwa kutentha: Kusintha kwa voliyumu komwe kumachitika chifukwa cha kusintha kwa kutentha, makamaka m’malo amene kutentha kumasiyana kwambiri usana ndi usiku.
Autogenous shrinkage: Panthawi ya simenti ya hydration, voliyumu yamkati imachepa chifukwa cha kumwa madzi ndi hydration reaction.
Ma shrinkage awa nthawi zambiri amabweretsa kupsinjika kwamkati mkati mwazinthuzo, pamapeto pake kumayambitsa ma microcracks kapena ming'alu, zomwe zimakhudza kulimba ndi kukongola kwa nyumbayo. Pofuna kupewa izi, zowonjezera zimafunikira kuti zinthu zitheke, ndipo HPMC ndi imodzi mwazo.
2. Kachitidwe ka HPMC
HPMC imagwira ntchito yofunika kwambiri pochepetsa kuchepa komanso kusweka kwa zida zomangira, zomwe zimatheka kudzera m'njira izi:
Kusunga madzi: HPMC ili ndi mphamvu yosungira madzi ndipo imatha kupanga filimu yosungira madzi mumatope kapena putty powder kuti muchepetse kutentha kwa madzi. Popeza nthunzi mofulumira wa madzi mkati mwa zinthu zidzachititsa shrinkage pulasitiki, madzi posungira zotsatira za HPMC akhoza bwino kuchepetsa oyambirira shrinkage chodabwitsa, kusunga madzi mu zinthu zokwanira, potero kulimbikitsa zonse hydration anachita wa simenti ndi kuchepetsa shrinkage ming'alu chifukwa. kutaya madzi pa kuyanika. Kuphatikiza apo, HPMC imatha kupititsa patsogolo magwiridwe antchito azinthu pansi pamikhalidwe yonyowa komanso youma ndikuchepetsa kusweka komwe kumachitika chifukwa cha kutaya madzi.
Kulimbitsa ndi kulimbitsa mphamvu: HPMC ndi thickener kuti angathe kuonjezera kusasinthasintha ndi mamasukidwe akayendedwe a matope ndi kupititsa patsogolo kumamatira kwa zinthu zonse. Panthawi yomanga, ngati zinthuzo ndi zoonda kwambiri, zimakhala zosavuta kuziyika kapena kugwedezeka, zomwe zimapangitsa kuti pakhale ming'alu kapena ming'alu. Pogwiritsa ntchito HPMC, matope amatha kukhala ndi kukhuthala koyenera, kukulitsa mphamvu ndi kachulukidwe pamwamba pa zinthu pambuyo pomanga, komanso kuchepetsa kuthekera kwa kusweka. Kuphatikiza apo, HPMC imathanso kukulitsa kukana kukameta ubweya wa zinthuzo ndikuwongolera kukana kwake ming'alu.
Sinthani kusinthasintha kwa zinthuzo: Mamolekyu a HPMC amatha kuchitapo kanthu popititsa patsogolo kusinthasintha kwa zinthu zopangidwa ndi simenti kapena zinthu zopangidwa ndi gypsum, kuti zinthuzo zikhale ndi mphamvu zolimba komanso zopindika pambuyo pochiritsa. Popeza zida zomangira nthawi zambiri zimakhala ndi kupsinjika kapena kupindika pansi pakusintha kwa kutentha ndi katundu, mutatha kuwonjezera HPMC, kusinthasintha kwa zinthuzo kumawonjezeka, komwe kumatha kuyamwa bwino kupsinjika kwakunja ndikupewa kusweka kwamphamvu.
Yang'anirani kuchuluka kwa simenti ya hydration: Muzinthu zopangira simenti, kuthamanga kwa hydration reaction rate kumakhudza mwachindunji magwiridwe antchito. Ngati hydration reaction ndi yofulumira kwambiri, kupsinjika mkati mwazinthu sikungathe kumasulidwa mu nthawi, zomwe zimapangitsa ming'alu. HPMC imatha kuchepetsa kutsika kwamadzimadzi kudzera mu kusungirako madzi komanso kupanga filimu yoteteza, kuteteza simenti kuti isatayike madzi mwachangu ikangoyamba kumene, motero kupewa zochitika za kuchepa kwapawiri ndi kusweka panthawi yakuuma kwa zinthuzo.
Kupititsa patsogolo ntchito yomanga: HPMC ikhoza kupititsa patsogolo ntchito yomanga ya zipangizo zomangira, zomwe zimawonetseredwa ndi madzi ake abwino, kusunga madzi ndi mafuta, kuonjezera kufanana kwa zipangizo, ndi kuchepetsa ming'alu yomwe imadza chifukwa cha zomangamanga zosayenera. Zitha kupanga matope, ufa wa putty, ndi zina zotero.
3. Kugwiritsa ntchito HPMC pazinthu zomangira zapadera
Zomatira matailosi: HPMC imatha kupititsa patsogolo ntchito zomatira zomatira matailosi, kuonetsetsa kuti matailosi amatha kumangirizidwa mofanana ndi gawo lapansi pakuyika, ndikuchepetsa kukhetsa kapena kusweka chifukwa cha kupsinjika kosagwirizana kapena kuchepa. Kuphatikiza apo, kukhuthala ndi kusunga madzi kwa HPMC kumathandiziranso zomatira matailosi kukhalabe ndi nthawi yayitali yotseguka pambuyo pomanga, kukonza bwino ntchito yomanga, komanso kuchepetsa ming'alu yomwe imayambitsidwa ndi kuchiritsa kosagwirizana.
Putty powder: Mu putty powder, katundu wosungira madzi wa HPMC angalepheretse putty kutaya madzi mofulumira panthawi yowuma, ndi kuchepetsa kuchepa ndi kusweka chifukwa cha kutaya madzi. Nthawi yomweyo, kukhuthala kwa HPMC kumatha kupititsa patsogolo ntchito yomanga ya putty, kupangitsa kuti ikhale yosavuta kugwiritsa ntchito mofanana pakhoma, ndikuchepetsa ming'alu yapamtunda yoyambitsidwa ndi kugwiritsa ntchito kosagwirizana.
Tondo: Kuwonjezera HPMC kumatope kumatha kupititsa patsogolo ntchito yake, kupangitsa kuti matope azikhala osalala panthawi yomanga, kuchepetsa tsankho ndi kusanja, motero kumapangitsanso kufanana ndi kumamatira kwa matope. Panthawi imodzimodziyo, kusungirako madzi kwa HPMC kungapangitse madzi kuti asungunuke pang'onopang'ono panthawi ya kuuma kwa matope, kupeŵa kuchepa ndi kusweka chifukwa cha kutaya madzi koyambirira.
4. Njira zodzitetezera pakugwiritsa ntchito HPMC
Kuwongolera Mlingo: Kuchuluka kwa HPMC yowonjezeredwa kumakhudza mwachindunji momwe imakhudzira, ndipo nthawi zambiri imayenera kusinthidwa molingana ndi kuchuluka kwa zinthu komanso mawonekedwe ogwiritsira ntchito. Kuchulukira kwa HPMC kumapangitsa kuti zinthuzo zikhale zokhazikika kwambiri, zomwe zimakhudza ntchito yomanga; pamene HPMC yosakwanira sidzatha kutenga gawo la kusunga madzi ndi kukhuthala monga momwe ziyenera kukhalira.
Gwiritsani ntchito ndi zina zowonjezera: HPMC nthawi zambiri imagwiritsidwa ntchito limodzi ndi zina zowonjezera mankhwala (monga zochepetsera madzi, mpweya wolowetsa mpweya, plasticizers, etc.) kuti akwaniritse zotsatira zabwino. Mukamagwiritsa ntchito, ndikofunikira kuganizira za kuyanjana kwazinthu zosiyanasiyana kuti mupewe kukhudzidwa kwa magwiridwe antchito.
Monga chowonjezera chomangira chofunikira, HPMC ili ndi mphamvu yayikulu pakuchepetsa kuchepa komanso kusweka kwa zida zomangira. Amachepetsa bwino ming'alu yomwe imabwera chifukwa cha kutayika kwa madzi ndi kupsinjika maganizo mwa kukonza kusungirako madzi, kukhuthala, kusinthasintha kwa zinthu komanso kukonza simenti ya hydration reaction rate. Kugwiritsa ntchito moyenera kwa HPMC sikungangowonjezera ntchito yomanga, komanso kukulitsa moyo wautumiki wa nyumbayo ndikuchepetsa mtengo wokonzanso pambuyo pake. Ndi kupita patsogolo kosalekeza kwaukadaulo wazinthu zomangira, kugwiritsa ntchito HPMC pantchito yomanga kudzakhala kokulirapo komanso mozama.
Nthawi yotumiza: Sep-21-2024