1. Vim li cas qhov adhesion ntawm galvanized coils feem ntau tsis zoo, thiab dab tsi yog qhov laj thawj tseem ceeb kom nkag siab ua ntej txhim kho adhesion?
Qhov tsis zoo adhesion ntawm galvanized coils feem ntau yog los ntawm ob qho laj thawj. Ua ntej, zinc txheej tau yooj yim tsim cov yeeb yaj kiab ntom ntom ntawm zinc oxide, zinc hydroxide, lossis zinc carbonate hauv huab cua. Cov yeeb yaj kiab no yog du thiab chemically inert, ua rau nws nyuaj rau cov xim zoo tib yam kom kis tau thiab ua raws li qhov zoo. Thib ob, txhawm rau tiv thaiv cov xeb dawb, galvanized coils feem ntau yog passivated ua ntej tawm hauv lub hoobkas. Cov zaj duab xis passivation ntxiv txo lub zog saum npoo, ua rau nws nyuaj rau cov txheej txheem los tsim cov khoom siv kho tshuab lossis cov khoom siv tshuaj lom neeg. Yog li ntawd, thawj kauj ruam ntawm kev txhim kho adhesion yog kom paub meej tias seb lub galvanized coil tau passivated thiab tshwj xeeb tshem tawm los yog hloov qhov kev thaiv no; txwv tsis pub, cov txheej tom ntej yuav yooj yim tev tawm hauv cov ntu loj.
2. Vim li cas lub cev sib tsoo lossis sandblasting zoo txhim kho adhesion? Dab tsi yuav tsum tau ceev faj thaum ua haujlwm?
Kev sib tsoo lub cev los yog xuab zeb blasting ua rau kom lub microscopic roughness ntawm galvanized coil nto los ntawm kev siv tshuab, tso cai rau cov txheej txheej rau hauv cov pits me me ntawm zinc txheej txheej, tsim "anchoring effect." Cov txheej txheem feem ntau suav nrog kev sib tsoo nrog 120-240 grit sandpaper, lossis sandblasting siv qis-siab sandblasting (siv tsis yog-hlau abrasives, xws li garnet xuab zeb). Muaj peb txoj kev ceev faj thaum lub sijhawm ua haujlwm: Ua ntej, lub siab yuav tsum tsis txhob siab dhau kom tsis txhob ua rau cov txheej txheem galvanized lossis txawm tias cov hlau substrate; thib ob, tom qab kev sib tsoo, cov plua plav thiab cov seem seem yuav tsum tau muab tshem tawm kom huv si nrog siab - cua siab lossis lub tshuab nqus tsev; thib peb, txheej yuav tsum tau siv sai li sai tau tom qab sib tsoo, qhov zoo tshaj plaws nyob rau hauv plaub teev, kom tsis txhob rov oxidation los yog paug ntawm qhov chaw. Tom qab sandblasting, adhesion tuaj yeem ua tau ntau dua ob npaug piv rau qhov chaw du.
3. Yuav ua li cas txhim kho adhesion siv cov tshuaj hloov pauv txheej txheej (xws li phosphating lossis passivation raws li lwm txoj kev kho mob)? Txoj kev twg yog qhov pom zoo tshaj plaws?
Cov txheej txheem tshuaj hloov pauv yuav tsim cov ntxeem tau, ntxhib inorganic ntsev txheej, xws li zinc phosphate, ntawm qhov chaw ntawm galvanized coils los ntawm cov tshuaj tiv thaiv. Cov txheej no ua raws li "choj," khov kho rau cov zinc txheej ntawm ib qho kawg thiab muaj micron - qhov loj ntawm qhov hws ntawm lwm qhov, tso cai rau cov primer nkag mus thiab tsim ib qho kev sib tshuam. Txoj kev pom zoo tshaj plaws yog "qis- kub zinc phosphating rau qhov chaw galvanized," nrog rau kev kho kub ntawm 40 thiab 60 degrees Celsius thiab lub sijhawm kho ntawm kwv yees li peb mus rau tsib feeb. Cov txiaj ntsig zinc phosphate crystals yog columnar lossis nplooj - zoo li, txhim kho adhesion. Rau cov workpieces loj uas tsis tuaj yeem muab tso rau hauv, ib qho txhuam hniav - siv cov tshuaj phosphating, tab sis cov nyhuv yog me ntsis qis dua. Hauv qhov sib piv, ib txwm chromate passivation, thaum xeb- tiv thaiv, tsis txhim kho adhesion thiab tsis pom zoo rau cov ntawv thov uas xav tau rov ua dua.
4. Hom primer lossis additive tuaj yeem txhim kho adhesion ncaj qha?
Yog tias koj tsis xav tau cov xuab zeb nyuaj lossis phosphating, koj tuaj yeem xaiv cov primer nrog cov pab pawg tshwj xeeb lossis ntxiv cov khoom txhawb nqa adhesion. Qhov zoo tshaj plaws primers yog epoxy zinc daj primer los yog epoxy zinc phosphate primer, uas tuaj yeem tsim cov tshuaj tiv thaiv nrog zinc txheej thiab tshwj xeeb tshaj yog haum rau galvanized substrates. Lwm txoj hauv kev yooj yim thiab muaj txiaj ntsig yog ntxiv qhov tshwj xeeb "galvanized sheet adhesion promoter" rau cov epoxy primer li niaj zaus, ntawm qhov ntau npaum li 3% mus rau 5% ntawm cov xim tseem ceeb, thiab do zoo ua ntej siv. Cov neeg txhawb nqa no feem ntau muaj cov phosphate esters lossis silane coupling cov neeg ua haujlwm, ib qho kawg ntawm cov tshuaj tiv thaiv nrog zinc nto thiab lwm qhov kawg crosslinks nrog cov xim zaj duab xis, ua kom zoo dua ntub thiab qhuav adhesion. Hauv qee cov dej-raws li cov xim ci, dej-raws li silane coupling agents kuj siv tau los ua kom muaj kev cuam tshuam zoo sib xws.
5. Yuav ua li cas thiaj kuaj xyuas sai sai tom qab kev txhim kho adhesion?
Feem ntau thiab txhim khu kev qha kev kuaj teb yog "cross- txiav adhesion test" thiab "kab kab xev kuaj." Cov txheej txheem tshwj xeeb: Siv tus ntoo khaub lig- txiav adhesion tester txiav ib daim phiaj nrog qhov sib nrug ntawm 1 hli lossis 2 hli ntawm cov txheej txheej kho. Qhov tob txiav yuav tsum nkag mus rau txheej txheej kom ncav cuag zinc txheej. Tom qab ntawd, siv 1-inch dav siab- daim kab xev nplaum (nrog rau qhov adhesion ntawm kwv yees li 10 Newtons ib 'meter') rau thaj tsam kab sib chaws, nias nws ruaj khov nrog lub lwv lossis koj cov ntiv tes, thiab tom qab ntawd nrawm dua daim kab xev ntawm 60-degree kaum sab xis. Ntsuam xyuas raws li ISO 2409 lossis ASTM D3359 tus qauv: Yog tias cov kab sib txuas ua tiav du thiab tsis muaj kev puas tsuaj, nws yog qib siab tshaj plaws, 0; yog tias tsuas yog me me ntawm tev tawm tshwm sim raws li kev txiav, nrog rau qhov chaw tev tawm tsis tshaj 5%, nws yog qib 1, uas kuj tau txais; Yog hais tias qhov chaw tev tawm yog nce ntau los yog cov cheeb tsam loj tev tawm, qhov adhesion yog qhov tsim nyog. Rau ntau qhov yuav tsum tau muaj, lub tshuab nqa nqa rub tawm adhesion tuaj yeem siv tau. Tom qab lub aluminium ingot yog kho rau ntawm txheej txheej, nws yog rub tawm vertically, thiab lub zog tensile ntawm qhov tsis ua hauj lwm raug kaw. Rau galvanized coils nrog ci enamel txheej, lub zog ntawm 5 MPa lossis siab dua yog feem ntau xav tau.