Redispersible polymer powders (RDPs) amagwira ntchito yofunika kwambiri m'mafakitale osiyanasiyana, kuphatikiza zomangamanga, zomatira, ndi zokutira. Mafawawa amagwiritsidwa ntchito kwambiri kuwongolera zida za simenti, kukulitsa kumamatira, kusinthasintha, komanso kulimba. Kumvetsetsa njira yopangira ma RDP ndikofunikira kuti opanga awonetsetse kuti zinthu zamtengo wapatali.
Zida zogwiritsira ntchito :
Kupanga kwa ufa wa polima wopangidwanso kumayamba ndikusankha mosamala zida zomwe zimakhudza zomwe zimapangidwira. Zigawo zazikuluzikulu zimaphatikizapo utomoni wa polima, ma colloid oteteza, mapulasitiki, ndi zowonjezera zosiyanasiyana.
Ma polima Resins: Ethylene-vinyl acetate (EVA), vinyl acetate-ethylene (VAE), ndi ma polima a acrylic amagwiritsidwa ntchito ngati ma polima akuluakulu. Ma resin awa amapereka kumamatira, kusinthasintha, komanso kukana madzi ku RDPs.
Chitetezo cha Colloids: Hydrophilic protective colloids monga polyvinyl alcohol (PVA) kapena cellulose ethers amawonjezedwa kuti akhazikitse tinthu tating'onoting'ono ta polima pakuyanika ndi kusungirako, kuteteza kuphatikizika.
Plasticizers: Plasticizers amathandizira kusinthasintha ndi kugwirira ntchito kwa RDPs. Plasticizer wamba amaphatikizapo glycol ethers kapena polyethylene glycols.
Zowonjezera: Zowonjezera zosiyanasiyana monga dispersants, thickeners, ndi cross-linking agents zikhoza kuphatikizidwa kuti ziwonjezere zinthu zina monga dispersibility, rheology, kapena mphamvu zamakina.
Njira Zopangira :
Kupanga kwa ufa wa polima wopangidwanso kumaphatikizapo njira zingapo zogwirira ntchito, kuphatikiza emulsion polymerization, kuyanika kwautsi, ndi njira zapambuyo pamankhwala.
Emulsion Polymerization:
Njirayi imayamba ndi emulsion polymerization, pomwe ma monomers, madzi, emulsifiers, ndi oyambitsa amasakanizidwa mu riyakitala pansi pa kutentha ndi kupanikizika. The monomers polymerize kupanga latex particles omwazikana m'madzi. Kusankhidwa kwa ma monomers ndi momwe zinthu zimakhalira zimatsimikizira kapangidwe ka polima ndi katundu.
Kukhazikika ndi Coagulation:
Pambuyo polima, latex imakhazikika powonjezera ma colloids oteteza ndi stabilizers. Izi zimalepheretsa tinthu coagulation ndikuonetsetsa kukhazikika kwa kupezeka kwa latex. Ma coagulation agents atha kuyambitsidwa kuti apangitse kusakanikirana kwa latex particles, kupanga coagulum yokhazikika.
Kuyanika Utsi:
The stabilized latex dispersion ndiye amadyetsedwa mu chowumitsira sprayer. Mu chipinda chowumitsira utsi, kubalalitsidwa kumasinthidwa kukhala madontho ang'onoang'ono pogwiritsa ntchito ma nozzles othamanga kwambiri. Mpweya wotentha umayambitsidwa nthawi imodzi kuti usungunuke madzi, ndikusiya tinthu tating'onoting'ono ta polima. Mikhalidwe yowumitsa, kuphatikizapo kutentha kwa mpweya wolowera, nthawi yokhalamo, ndi kuchuluka kwa mpweya wa mpweya, zimakhudza kapangidwe ka tinthu ndi ufa.
Pambuyo pa Chithandizo:
Kutsatira kuyanika kwa utsi, ufa wa polima womwe umachokera umalowa m'machitidwe achipatala kuti ukhale wokhazikika komanso wokhazikika. Njirazi zingaphatikizepo kusinthidwa pamwamba, granulation, ndi kulongedza.
a. Kusintha kwa Pamwamba: Zogwiritsa ntchito pamwamba kapena zolumikizira zolumikizira zitha kugwiritsidwa ntchito kuti zisinthe mawonekedwe amtundu wa tinthu ta polima, kupititsa patsogolo dispersibility ndi kugwirizana ndi zida zina.
b. Granulation: Kupititsa patsogolo kagwiridwe ndi dispersibility, ndi polima ufa akhoza kukumana granulation kubala yunifolomu tinthu kukula ndi kuchepetsa fumbi mapangidwe.
c. Kupaka: Ma RDP omaliza amapakidwa m'matumba osamva chinyezi kuti aletse kuyamwa kwa chinyezi ndikusunga bata panthawi yosungira ndikuyenda.
Njira Zowongolera Ubwino:
Kuwongolera kwaubwino ndikofunikira panthawi yonse yopangira kuti zitsimikizire kusasinthika komanso kudalirika pazinthu za ufa wa polima wopangidwanso. Zofunikira zingapo zimawunikidwa ndikuwongoleredwa pamagawo osiyanasiyana:
Ubwino Wazinthu Zakuthupi: Kuyang'ana mozama ndikuyesa zida zopangira, kuphatikiza ma polima, ma colloid, ndi zowonjezera, zimachitika kuti zitsimikizire mtundu wawo, kuyera, komanso kugwilizana ndi zomwe akufuna.
Kuyang'anira Njira: Zofunikira zofunika kwambiri monga kutentha, kuthamanga, kuchuluka kwa chakudya cha monomer, ndi kuyanika kumawunikidwa mosalekeza ndikusinthidwa kuti zisungidwe bwino komanso kusasinthasintha.
Kapangidwe ka Tinthu: Kugawa kwa tinthu tating'onoting'ono, morphology, ndi mawonekedwe a pamwamba pa ufa wa polima amawunikidwa pogwiritsa ntchito njira monga laser diffraction, electron microscopy, ndi kusanthula kwamtunda.
Kuyesa Magwiridwe: Mafuta a polima opangidwanso amayesedwa mozama kuti awone mphamvu zawo zomatira, kapangidwe ka filimu, kukana madzi, komanso makina amakina malinga ndi miyezo yamakampani komanso zomwe makasitomala amafuna.
Kuyesa Kukhazikika: Mayesero ofulumira okalamba ndi maphunziro okhazikika amachitidwa kuti awone kukhazikika kwa nthawi yayitali kwa RDPs pansi pazikhalidwe zosiyanasiyana zosungirako, kuphatikizapo kusiyana kwa kutentha ndi chinyezi.
Kupanga redispersible polima ufa kumaphatikizapo zovuta zingapo, kuyambira emulsion polymerization mpaka kupopera kuyanika ndi pambuyo mankhwala. Poyang'anira mosamala zinthu zopangira, zomangira, ndi njira zowongolera zabwino, opanga amatha kuwonetsetsa kuti ma RDPs ndi abwino komanso magwiridwe antchito osiyanasiyana pamafakitale omanga, zomatira, ndi zokutira. Kumvetsetsa zovuta za momwe ntchito yopangira zinthu zimapangidwira ndikofunikira kuti muwongolere mawonekedwe azinthu ndikukwaniritsa zosowa zamakasitomala pamsika.
Nthawi yotumiza: Mar-12-2024