Dhayi ndeye organic compound, kazhinji pamberi pemamiriro emvura kupedzisa kemikari yekuita, saka dhayi yekutanga yenyika inotanga kutengeswa mumhando yemvura, hongu, iyo yepakutanga yedhayi yemhando ine reshiyo yemazuva ano iri kure, inogona chete. Kuonekwa semhando yepakutanga yedhayi yemvura nhasi.Panguva iyoyo, inenge 20% yezvigadzirwa zvaive mvura, uye idzi dhayi dzemvura dzainyanya dhayi dzeVAT uye dhayi dzemordant.

Muna 1923, maBritish akatanga awedzera mamwe akasarudzwa padhayi yepakutanga uye mushure mekukuya, akaita kuti isanyungudika disperse dhayi aqueous dispersion. Pakazosvika 1910, dhayi zhinji dzaive dzabviswa uye dzakagadziriswa kuita hupfu hwakatsetseka hweimwe saizi.

Maererano nemabhuku e1924, panguva iyoyo inenge 80% yekugadzirwa kwedhayi muhupfu hwakatsetseka, madhayi eVAT akagadzirwa mumhando dzakasiyana-siyana dzekugovera saizi, kubva kune yakanakisa kusvika ku50um yehupfu dhayi zvinhu. yehuruva yakakomba uye kusanyorova kwemvura.

Mushure me1930, madhayi emhando yekuparadzira akagadziridzwa, asi pachine zvimwe zvinokanganisa senge kunaya kuri nyore uye kusagadzikana kwekuchengetedza.

Iye zvino iyo dhayi yemvura mushure mekugadzirisa kugadzirwa kwemaitiro akasiyana-siyana yakagadziridzwa zvakanyanya, nguva yekuchengetedza inogona kusvika kupfuura hafu yegore pasina kuparara, yemvura yekugadzira dhayi mutengo yakaderera, iri nyore kushandisa uye yagara ichigadzirwa.

Kubva 1950, kubuda kwemuchina wejecha kwakasimudzira kuvandudzwa kwehunyanzvi hwekurapa mushure mekurapa.Kunyorova nekukuya nemushini wejecha kunogona kuwana akatsetseka uye akatetepa zvimedu.Mukuwedzera, iyo nzira yekugadzira yakagadziridzwa kuitira kuti zvimedu zvedhayi zvisvike kusvika 1um, uye mhando yezvigadzirwa zvinogadzirwa nemaitiro matsva nemidziyo yakavandudzwa zvakanyanya. uye kugadzirwa kwedhayi dzisinganyungudika kwakafambira mberi zvikuru.

Nekufambira mberi kwemichina yemakemikari nemidziyo yemakemikari, dhayi dzegranular dzakatanga kuoneka. Granular dhayi yairatidza granularity ye100 ~ 300 um, iine maburi particles zvakare ane yakasimba particles, liquidity iri nani pane dhayi yehupfu, kunyorova, kupararira, uye zvakare inokunda. iyo dhizaini yehupfu dhayi guruva rinoyangarara mudenga, mafomu emuyero akaonekwa pakarepo akagamuchirwa nedhipatimendi rekugadzira nekushandisa, zvino madhayi mazhinji akagadziriswa kuita zvigadzirwa zvegranular.