Mechanism of Redispersible Emulsion Powder mu Dry Mix Mortar

Redispersible latex ufa ndi zomatira zina zopanda organic (monga simenti, laimu slaked, gypsum, dongo, etc.) ndi aggregates osiyanasiyana, fillers ndi zina zowonjezera [monga hydroxypropyl methylcellulose, polysaccharide (wowuma efa), CHIKWANGWANI CHIKWANGWANI, etc.] mumtondo wosakanizika wowuma posakaniza mwakuthupi. Pamene matope a ufa wowuma awonjezeredwa m'madzi ndikugwedezeka, pansi pa mphamvu ya hydrophilic protective colloid ndi makina ometa ubweya wa ubweya, tinthu tating'onoting'ono ta latex tingathe kumwazikana m'madzi, zomwe zimakhala zokwanira kupanga ufa wa latex wosakanizidwa kukhala wofewa. kanema. The zikuchokera mphira ufa ali ndi zotsatira zosiyana pa rheological katundu wa matope ndi zosiyanasiyana zomangamanga katundu: kuyanjana kwa latex ufa madzi pamene iwo anabalalitsidwa, ma viscosities osiyana a latex ufa pambuyo kubalalika, mmene mpweya zili. wa matope ndi kugawa mpweya thovu, The kugwirizana pakati pa mphira ufa ndi zina zina zimapangitsa osiyana lalabala ufa ndi zotsatira za kuwonjezeka fluidity, kuwonjezeka thixotropy, ndi kuwonjezereka mamasukidwe akayendedwe.

Nthawi zambiri amakhulupirira kuti njira ya redispersible latex ufa kuti ipititse patsogolo kugwira ntchito kwa matope atsopano ndi: kuyanjana kwa ufa wa latex, makamaka colloid yoteteza, kumadzi pamene imabalalitsidwa, kumawonjezera kukhuthala kwa slurry, komanso kumapangitsanso mgwirizano wa matope. matope omanga.

Pambuyo matope osakanikirana omwe ali ndi latex powder dispersion apangidwa, ndi kuyamwa kwa madzi ndi pansi pamtunda, kumwa kwa hydration reaction, ndi kuphulika kwa mpweya, madzi adzachepa pang'onopang'ono, tinthu tating'onoting'ono timayandikira pang'onopang'ono, mawonekedwe. zidzasokoneza pang'onopang'ono, ndipo utomoniwo udzasakanikirana pang'onopang'ono. pamapeto pake adapangidwa kukhala filimu. Njira yopanga filimu ya polima imagawidwa m'magawo atatu. Mu gawo loyamba, polima particles kusuntha momasuka mu mawonekedwe a Brownian zoyenda mu koyamba emulsion. Madzi akamasanduka nthunzi, kusuntha kwa tinthu ting’onoting’ono kumakhala koletsedwa mwachibadwa, ndipo kukangana kwapakati pa madzi ndi mpweya kumawachititsa kuti agwirizane pang’onopang’ono. Mu gawo lachiwiri, pamene tinthu tating'onoting'ono takumana ndi mzake, madzi maukonde amasanduka nthunzi kudzera capillary machubu, ndi mkulu capillary mavuto ntchito pamwamba pa particles kumapangitsa mapindikidwe a latex spheres kusakaniza iwo pamodzi, ndi madzi otsala amadzaza pores, ndipo filimuyo imapangidwa mozungulira. Gawo lachitatu, lomaliza limalola kufalikira (nthawi zina kumatchedwa kudziphatika) kwa mamolekyu a polima kuti apange filimu yeniyeni yopitilira. Pakupanga filimu, tinthu tating'onoting'ono ta latex tating'onoting'ono timaphatikizana kukhala gawo latsopano la kanema wokhala ndi kupsinjika kwakukulu. Mwachiwonekere, kuti athe redispersible polima ufa kupanga filimu mu matope owuma, m'pofunika kuonetsetsa kuti osachepera filimu kupanga kutentha (MFT) ndi otsika kuposa kuchiritsa kutentha kwa matope.

Colloids - mowa wa polyvinyl uyenera kulekanitsidwa ndi filimu ya polima. Ili si vuto mu dongosolo la matope a alkaline simenti, chifukwa mowa wa polyvinyl udzakhala saponified ndi alkali wopangidwa ndi simenti ya simenti, ndipo kutsekemera kwa zinthu za quartz kumalekanitsa pang'onopang'ono mowa wa polyvinyl ku dongosolo, popanda hydrophilic protective colloid. , Kanema wopangidwa ndi kufalikira kwa nthawi imodzi ya ufa wopangidwanso wa latex, womwe umakhala wosasungunuka m'madzi, sungathe kugwira ntchito mumikhalidwe yowuma, komanso kumizidwa m'madzi kwa nthawi yayitali. Inde, mu machitidwe osakhala amchere, monga gypsum kapena filler-okha machitidwe, chifukwa mowa wa polyvinyl udakalipo pang'ono mu filimu yomaliza ya polima, yomwe imakhudza kukana kwa madzi kwa filimuyi, pamene machitidwewa sagwiritsidwa ntchito kwa nthawi yaitali. kumizidwa , ndipo polima akadali ndi mawonekedwe ake apadera amakina, ndipo ufa wa polima wopangidwanso ukhoza kugwiritsidwabe ntchito m'machitidwe awa.

Ndi mapangidwe omaliza a filimu ya polima, dongosolo lopangidwa ndi zinthu zopanda organic ndi organic binder limapangidwa mumatope ochiritsidwa, ndiko kuti, chigoba chophwanyika komanso cholimba chopangidwa ndi zida zamagetsi, ndipo ufa wopangidwanso ndi latex umapanga filimu pakati pa kusiyana ndi pamwamba olimba. flexible network. Kulimba kwamphamvu ndi kulumikizana kwa filimu ya utomoni wa polima yopangidwa ndi ufa wa latex kumakulitsidwa. Chifukwa cha kusinthasintha kwa polima, mphamvu yopindika ndiyokwera kwambiri kuposa momwe miyala ya simenti yolimba, kusinthika kwa matope kumatheka, ndipo zotsatira za kubalalitsa kupsinjika zimakula bwino, potero kuwongolera kukana kwa matope. .

Ndi kuchuluka kwa zili redispersible latex ufa, dongosolo lonse akufotokozera pulasitiki. Pankhani ya high latex ufa okhutira, ndi polima gawo mu matope anachiritsa pang`onopang`ono kuposa inorganic hydration mankhwala gawo, ndi matope adzakhala kusintha Mkhalidwe ndi kukhala elastomer, pamene hydration mankhwala a simenti amakhala "filler". “. Kulimba kwamphamvu, kusinthasintha, kusinthasintha ndi kusindikizidwa kwa matope osinthidwa ndi redispersible latex powder zonse zimakhala bwino. Kusakanikirana kwa ufa wa latex wopangidwanso kumapangitsa kuti filimu ya polima (filimu ya latex) ipange ndi kupanga gawo la makoma a pore, potero kusindikiza mawonekedwe otsekemera kwambiri a matope. Nembanemba ya latex imakhala ndi njira yodzitambasulira yokha yomwe imapangitsa kugwedezeka komwe kumakakamira kumatope. Kupyolera mu mphamvu zamkati izi, matope amasungidwa lonse, motero amawonjezera mphamvu yogwirizana ya matope. Kukhalapo kwa ma polima osinthika kwambiri komanso zotanuka kwambiri kumapangitsa kuti matopewo asasunthike komanso kusinthasintha.

Njira yowonjezerera kupsinjika kwa zokolola ndi kulephera mphamvu ndi motere: pamene mphamvu ikugwiritsidwa ntchito, ma microcracks amachedwa mpaka kupanikizika kwakukulu kufikiridwa chifukwa cha kusinthasintha ndi kusinthasintha. Kuonjezera apo, madera osakanikirana a polima amalepheretsanso kugwirizanitsa kwa microcracks mu ming'alu yolowera. Choncho, redispersible polima ufa amathandizira kulephera kupsinjika ndi kulephera kwa zinthuzo.

Filimu ya polima mumatope osinthika a polima imakhala ndi zotsatira zofunikira kwambiri pakuwumitsa matope. The redispersible latex ufa wogawira pa mawonekedwe amasewera gawo lina lofunika pambuyo pobalalitsidwa ndi kupanga mafilimu, zomwe zimawonjezera kumamatira kuzinthu zomwe zimagwirizana. Mu microstructure ya ufa polima kusinthidwa matailosi kugwirizana matope ndi matailosi mawonekedwe, filimu yopangidwa ndi polima amapanga mlatho pakati pa matailosi vitrified ndi otsika kwambiri mayamwidwe madzi ndi masanjidwewo simenti matope. Malo olumikizirana pakati pa zinthu ziwiri zosiyana ndi malo omwe ali pachiwopsezo chachikulu kuti ming'alu ya shrinkage ipangike ndikupangitsa kutayika kwa mgwirizano. Choncho, kuthekera kwa mafilimu a latex kuchiritsa ming'alu ya shrinkage ndikofunikira kwambiri pazomatira zamatayilo.

Pa nthawi yomweyo, redispersible latex ufa munali ethylene ali kwambiri adhesion kwa magawo organic, makamaka zipangizo zofanana, monga polyvinyl kolorayidi ndi polystyrene. Chitsanzo chabwino ndi pankhani ya masks.