Mbiri Yachitukuko ya Redispersible Powder

Redispersible powder (RDP) ndi mtundu wa ufa wa polima womwe umagwiritsidwa ntchito m'makampani omanga monga chowonjezera muzinthu zopangidwa ndi simenti monga matope, ma grouts, ndi zodzipangira zokha. Ma RDP adapangidwa koyamba m'zaka za m'ma 1950s ndipo kuyambira pamenepo akhala gawo lofunikira pazomangira zamakono. M'nkhaniyi, tiwona bwino mbiri yachitukuko cha RDP komanso kufunikira kwake pantchito yomanga.

Zaka zoyambirira

Ma RDP oyamba adapangidwa mu 1950s ndi kampani yaku Germany yotchedwa Wacker Chemie AG. Panthawiyo, Wacker Chemie AG anali kupanga zida zatsopano zopangira kuti akwaniritse zofuna zomwe zikukula pambuyo pa nkhondo. Iwo anali kufunafuna njira yopititsira patsogolo zinthu za simenti, monga kukana madzi, kulimba, ndi kusinthasintha.

M'masiku oyambirira, RDPs anapangidwa ndi kusungunuka polyvinyl acetate (PVA) mu zosungunulira ndiyeno kupopera mankhwala m'chipinda chotenthetserako kumene zosungunulira zimasanduka nthunzi, kusiya kumbuyo ufa wabwino. Ufawu ukhoza kumwazidwa mosavuta m'madzi ndikugwiritsidwa ntchito ngati chowonjezera muzinthu zopangidwa ndi simenti.

Komabe, panali zolepheretsa ku mtundu woyamba wa RDP uwu. Mwachitsanzo, zinali zovuta kulamulira kukula kwa tinthu ndi mawonekedwe a ufa, zomwe zingakhudze ntchito yake muzinthu za simenti. Kuonjezera apo, ufawo sunali wosasunthika kwambiri ndipo nthawi zambiri umapanga zotupa kapena zotupa, zomwe zimapangitsa kuti zikhale zovuta kuzigwiritsa ntchito.

Zowonjezera ndi zatsopano

Kwa zaka zambiri, ofufuza ndi mainjiniya apanga kusintha kwakukulu pakupanga ndi katundu wa RDPs. Mwachitsanzo, kupita patsogolo kwa chemistry ya polima kwapangitsa kuti pakhale ma polima atsopano omwe amapereka magwiridwe antchito komanso kukhazikika.

Chimodzi mwazofunikira kwambiri paukadaulo wa RDP chidabwera m'zaka za m'ma 1980 ndikuyambitsa njira yatsopano yopangira yotchedwa spray drying. Njirayi imaphatikizapo kupopera mankhwala a polima emulsion m'chipinda chotentha chomwe madzi amatuluka, ndikusiya ufa wabwino. Njirayi inalola kuti pakhale kulamulira kwakukulu pa kukula kwa tinthu ndi mawonekedwe a ufa, zomwe zimapangitsa kuti zikhale zogwira mtima komanso zodziwikiratu muzinthu za simenti.

Chidziwitso china mu luso la RDP chinabwera ndi kuyambitsa kwa redispersible latex powder (RPL), yomwe imapangidwa kuchokera ku latex emulsion m'malo mwa PVA. Ma RPLs amapereka kukana kwamadzi bwino komanso kumamatira poyerekeza ndi ma RDP opangidwa ndi PVA, kuwapanga kukhala chisankho chodziwika bwino pamapulogalamu akunja monga stucco ndi EIFS (kutsekereza kwakunja ndi dongosolo lomaliza).

Mapulogalamu ndi maubwino

Ma RDP amapereka maubwino angapo pantchito yomanga, kuphatikiza kuwongolera magwiridwe antchito, kumamatira, komanso kukana madzi. Zitha kugwiritsidwa ntchito pazinthu zosiyanasiyana za simenti, kuphatikizapo matope, ma grouts, mankhwala odzipangira okha, ndi zomatira matailosi.

Ubwino umodzi wofunikira wa RDPs ndikutha kuwongolera magwiridwe antchito komanso kusavuta kugwiritsa ntchito zinthu zopangidwa ndi simenti. Amatha kuchepetsa kuchuluka kwa madzi ofunikira kuti akwaniritse kugwirizana komwe kukufunikira, zomwe zingapangitse mphamvu ndi kukhazikika kwa mankhwala omalizidwa. Zingathandizenso kuchepetsa kung'ambika ndi kuchepa, zomwe zingatheke ngati zopangira simenti ziuma mofulumira kwambiri.

Kuphatikiza apo, ma RDP amatha kupititsa patsogolo kumamatira kwa zinthu zopangidwa ndi simenti ku magawo osiyanasiyana, kuphatikiza matabwa, zitsulo, ndi zomangamanga. Athanso kukonza kukana kwamadzi ndi kulimba kwa zinthu zopangidwa ndi simenti, kuzipanga kukhala zabwino kugwiritsidwa ntchito m'malo amvula kapena madera omwe ali ndi kuchuluka kwa magalimoto kapena kukhudzidwa.

Mapeto

Pomaliza, mbiri yachitukuko cha RDP yadziwika ndi kupita patsogolo kwakukulu mu chemistry ya polima ndi njira zopangira. Kuyambira pomwe idayamba m'zaka za m'ma 1950, RDP yakhala gawo lofunikira pazomangira zamakono, zopatsa maubwino osiyanasiyana pogwira ntchito, kumamatira.