I-ejenti yokususa igesi iyi-ejenti esekelayo ekhipha izinto eziguquguqukayo njengomoya, umswakama, kanye namakhemikhali amancane e-molecule akhiqizwa ngesikhathi sokusabela kokuxhumanisa nokuqina kwe-powder coatings lapho zincibilika futhi zakha ifilimu. Iphinde ikhokhele imigodi ye-pinhole yamakhemikhali amancane e-molecule akhishwe ngesikhathi esifanele, igweme ukuvela kwemigodi emincane ye-pinhole noma i-pores efilimu yokuhlanganisa. Lolu hlobo lwe-additive lungenye yezithasiselo ezivamile ezimbozweni ze-powder, futhi luvame ukungezwa ekwakhiweni kwe-powder coatings.
I-ejenti yokususa igesi esetshenziswa kakhulu ezimbozweni zempuphu yi-benzoin. I-Benzoin iyikristalu emhlophe noma ephuzi ekhanyayo engenaphunga enephuzu lokuncibilika elingu-133-137 ℃ kanye nephuzu lokubila elingu-344 ℃. Incibilika kancane emanzini nase-ether, futhi incibilika ku-acetone eshisayo kanye ne-ethanol; Ububi bayo ukuthi ingabangela kalula ukuphuzi kwephethini emazingeni okushisa aphezulu. Ukuze kunqotshwe izinkinga ze-benzoin,ama-ejenti okususa igesi asekelwe ku-benzoin kanye ne-waxawekho amathuba okuba phuzi ngaphansi kwezimo zokubhaka nokuphola.
Imiphumela yokuhlolwa kanye nemikhuba yokukhiqiza ikhombisa ukuthi ngesikhathi senqubo yokuxhumanisa nokulungisa i-powder coating, izinhlobo ze-coating ezikhiqiza ama-molecule amancane zidinga ukungezwa kwama-degassing agents. Kunengqondo ukwengeza i-degassing agent ku-epoxy, epoxy polyester, polyester, kanye ne-polyurethane powder coatings evamile ngoba i-powder coatings inezinkinga ezifana nokumuncwa kalula komswakama ngesikhathi sokukhiqizwa nokusetshenziswa. Ku-epoxy matte kanye ne-matte powder coatings, akulula ukukhiqiza ama-pinholes kanye nezinye izinkinga ngaphandle kokufakwa kwama-defoamers njenge-benzoin. Isizathu asikwazi ukuchazwa ngokucacile okwamanje, futhi kungenzeka futhi ukuthi kungenxa yokuthi ubuso be-coating abusheleli futhi bucwebezela njengokucwebezela okuphezulu, kanye nezinye izinkinga ze-coating ezingacacile, okuholela ekuzizweni.
Njengamanje, i-benzoin iseyi-ejenti yokususa igesi esetshenziswa kakhulu, enomthamo ongaba ngu-0.5% wezinto zokwakha ifilimu ezimbozweni zempuphu, ezingalungiswa ngokufanele ngaphakathi kobubanzi obuthile ngokuya ngezinhlobonhlobo nokwakheka kwezingubo zempuphu. Ezimbozweni zempuphu ze-polyester-HAA (hydroxyalkylamide), uma kucatshangelwa ithonya le-benzoin ekuphuzeni kwefilimu yokumboza, umthamo wayo kufanele ulawulwe cishe ku-0.3% wenani eliphelele lezinto zokwakha ifilimu, futhi ukusetshenziswa kufanele kuncishiswe ngangokunokwenzeka.Ngaphezu kwalokho, izinto zokwenza izinto ezibushelelezi nezisusa igesi ezisekelwe ku-wax zokwenziwa nazo zingasetshenziswa, ngomthamo ongaba ngu-1% wefomula ephelele yokumboza ngempuphu.
Ekwakhekeni kwe-powder coating, ama-defoamer ayengezwa ku-cast iron, i-cast aluminium, ama-hot-dip steel galvanized plates, kanye nama-hot-rolled steel plates anezimbobo zesihlabathi noma ama-pinholes ebusweni bento ehlanganisiwe (i-workpiece) ngesikhathi se-powder coating ukuvimbela ukwakheka kwezinhlayiya noma imigodi yentaba-mlilo efilimini yokumboza. Ziyizithasiselo ezingeziwe ukuvimbela ukwakheka kwama-bubbles efilimini yokumboza.
Uma kufakwa i-powder coating ezingxenyeni zensimbi ezibunjiwe, izingxenye ze-aluminium ezibunjiwe, izingxenye ze-galvanized ezifakwe ngokushisa noma amapuleti ensimbi aguqiwe ngokushisa anezimbobo zesihlabathi noma imigodi ye-pinhole, ngesikhathi senqubo yokubhaka nokulungisa, i-powder coating iyancibilika futhi ithambe ngenkathi ivala izimbobo zesihlabathi kanye nemigodi ye-pinhole ebusweni bento eboshiwe. Njengoba izinga lokushisa lezinto ezibunjiwe landa, umoya ezimbobeni zesihlabathi kanye nemigodi ye-pinhole yezinto ezibunjiwe uyakhula, futhi ingcindezi yangaphakathi nayo iyanda njalo. Lapho ingcindezi yangaphakathi inkulu kancane kunamandla e-coating encibilikisiwe, umoya wangaphakathi uzoqhumisa i-coating bese wenza ama-bubble amancane ukuze aphume. Ngenxa yokusabela kokuqina kwe-powder coating ngesikhathi senqubo yokwakha ifilimu, i-viscosity yokuncibilika kwe-coating iyanda njalo futhi ekugcineni iba yi-solid coating film. Ngakho-ke, lapho ingcindezi yangaphakathi kuma-bubble amancane ingafinyeleli amandla adingekayo ukuze kuqhume ifilimu eboshiwe, la ma-bubble amancane akha izinhlayiya noma ama-granule avela ebusweni befilimu eboshiwe. Lapho ingcindezi yangaphakathi e-bubble encane yanele ukuqhuma i-coating, i-bubble encane izoqhuma futhi umoya ongaphakathi uzophuma uye emkhathini. Uma ungqimba kulesi sigaba lulahlekelwe ikhono lalo lokulinganisa futhi lungakwazi ukuvala imigodi emincane yomoya evumela umoya ukuba uphume, kuzokwakheka izinhlayiya noma ama-granule ajwayelekile e-volcanic crater, abe yinkinga enkulu.
Uma ama-defoamer engezwa ezimbozweni zempuphu, anganciphisa ukuncibilika kwengubo yempuphu futhi anciphise nokucindezeleka kobuso bengubo. Lokhu kuvumela umoya osemabhodleleni esihlabathi kanye nasezimbotsheni eziphezu kwezinto ezimboziwe, ezithintwa izinga lokushisa lokubhaka kanye nengcindezi, ukuthi uqhume kalula futhi unciphise ifilimu yokumboza engakapheki uye emkhathini. Ngesikhathi esifanayo, izikhala ezikwifilimu yokumboza lapho amabhamuza ephuma khona zingabhidliza kalula ukuleveli, kuvimbele ukwakheka kwezinhlayiya kanye nezinhlayiya kwifilimu yokumboza, noma izinhlayiya ezinemigodi yentaba-mlilo.
Ngenxa yokuthi izindlela zokususa i-foam zezingubo ezisekelwe emanzini kanye ne-solvent zihluke ngokuphelele kwezezingubo ezifakwe i-powder, ama-defoam asetshenziswa ezigqokeni ezisekelwe emanzini kanye ne-solvent awakwazi ukusetshenziswa ngqo ezigqokeni ezifakwe i-powder. Ngenxa yobukhulu bezingubo ezifakwe i-powder, azikho izinhlobo eziningi zezingubo ezisetshenziswa ezigqokeni ezisekelwe emanzini kanye nezingubo ezisekelwe kwi-solvent.
Isikhathi sokuthunyelwe: Agasti-15-2025