Isikhathi sokubhoshwa kwezithakazelo kwezithakazelo kuzindaba zemithambo yezindustria

Izikhathi Zokuqina Okujwayelekile Ngokwe-thermosetting Powder Coating Chemistry

Amapholiyesta, ama-epoxy, ama-urethane, nezinhlelo ezihlanganisiwe: isikhathi esivamile/amafasitela okushisa (160200°C, 1025 min)

Konke ukuthi kubhekwa kwezinkulungwane zokugcina kwezinkulungwane zokugcina kuzodinga ukuthi kubhekwe kwezinkulungwane zokugcina ngokuphelele kwezinkulungwane zokugcina. Izisikhi zesipho sesipho—ezithandekayo ngokuthi ziyasebenza kahle kusuka emuva—zihambisana ngokuvamile kwi-180–200°C ngemizuzu yezinkulungwane zokugcina yezinkulungwane zokugcina. Izisikhi zesipho sesipho—ezithandekayo ngokuthi ziyasebenza kahle kusuka emuva—zihambisana ngokuvamile kwi-160–180°C ngemizuzu yezinkulungwane zokugcina yezinkulungwane zokugcina. Izisikhi zesipho sesipho—ezithandekayo ngokuthi ziyasebenza kahle kusuka emuva—zihambisana ngokuvamile kwi-160–190°C ngemizuzu yezinkulungwane zokugcina yezinkulungwane zokugcina. Izisikhi zesipho sesipho—ezithandekayo ngokuthi ziyasebenza kahle kusuka emuva—zihambisana ngokuvamile kwi-180–200°C ngemizuzu yezinkulungwane zokugcina yezinkulungwane zokugcina. Itafula ezansi iyagcina lezi zikhathi zokugcina zokuvamile.

Ngaphakathi kweminye yonke imbono, amaqhagasi angabuyekeza isikhathi noma isikhashana ngaphandle kokuthi ibe nemiphumela emifanayo yokugqamisa—ukusukela ukuthi isikhashana sesithili (PMT) sokuphakathi kwezinto ziyafika ekuthi kubhekwe. Ukukhetha ukuchaza okuhle kuvumela ukuthi umsebenzi wokuproducwa uyasebenza ngokwanele futhi ukuthi kusebenze ngokwanele kusasa.

Amaphulimi okuchitha phansi nokuphatha ngokuphelele: ukwenza ukuthi kubhekwe ngokufanayo kwezinto ezinomthwalo wekhanda

Izintemperatura zokuhlanza kahle (160–200°C) ziyakha umcimbi wokuvula izihlangothi ezisemthwakathini kakhulu njenge-MDF, izihlangothi zesilika, nokhokho lwesilika esincane. Izinkulungwane zokuhlanza phansi zokuhlanza kahle zisivumela ukuthi zihlanze kusukela ku-120–150°C—kanye nesikhathi sokuhlala eside (20–30 minithi) noma ukuthuthukisa ngokusebenzisa amakatalisti. Nangona zibuyela ukuthi zinamandla okugqamisa kanye nokubhekana nomthelela, kungabikho izinkinga ezingaphansi kwezinhlobo zokuhlanza phansi njengekhuphulo elincane noma ukuphambuka kwamandla. Ngokwesibonelo, izinhlobo zezinkulungwane zokuphatha kakhulu—ezwenziwe ukuthi zisebenze emizimbeni eyinkulu njengezindawo zokuphatha emhlabeni noma ukuphatha amakhemikhali—zisebenza kusukela ku-200–220°C ngemizuzu yami-15–25 ukuze zihlanganise kakhulu nokubeka isibonelo sokubaluleka. Lezi zinhlobo zezinkulungwane eziphinde zidlula zisivumela ukuthi izinkulungwane zihlanze kuzo zonke izihlangothi ezazisemthwakathini kakhulu, ngaphandle kokuthi kubhekwe isibonelo sokubaluleka.

Kungani i-Part Metal Temperature (PMT) — Akunye ne-oven air temperature — Yodetermina isikhathi sokuhlanza kahle

Abaningi abasebenzisi baphinda bavula isikhathi sokugcina lapho umoya wendawo yomkhumbi uyafika emoyeni wokugcina. Ngempela, indlela yokugcina iyadlala kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela lapho isikhathi sokugcina sivula kuphela...... isikhathi sokugcina sesithuthi (PMT) sifika emoyeni wokugcina—akukho umoya wendawo. Isibonelo, uma isithombe sesayensi sayisho '12 iminithi ngempi 200°C', lokhu kusobala ukuthi isikhathi sokugcina sivula kuphela lapho isithuthi sifika empi 200°C. Umoya wendawo ayisibonelo esihlakanipha: izinto ezinkulu, izinto ezingafanele, noma izinto zokugcina ziyabuyisa ukuchitha okuphambili nokungafanele kokugcina. PMT ibonisa amandla okugcina okusebenzayo okuyadlala ukubeka iziqondiso—futhi iyahluka kakhulu ngokwezindlela zokugcina nezindawo. Izinto ezincane zingafika emoyeni wokugcina ngeminithi eyi-5–10; izinto ezinkulu noma izinto eziningi zingadinga iminithi eyi-30+ kuphela ukufika emoyeni wokugcina. emva isithuthi sifika empi 200°C. Umoya wendawo ayisibonelo esihlakanipha: izinto ezinkulu, izinto ezingafanele, noma izinto zokugcina ziyabuyisa ukuchitha okuphambili nokungafanele kokugcina. PMT ibonisa amandla okugcina okusebenzayo okuyadlala ukubeka iziqondiso—futhi iyahluka kakhulu ngokwezindlela zokugcina nezindawo. Izinto ezincane zingafika emoyeni wokugcina ngeminithi eyi-5–10; izinto ezinkulu noma izinto eziningi zingadinga iminithi eyi-30+ kuphela ukufika emoyeni wokugcina. angabi isiphakathi sezinhlobo zokulwa—kuyizikhathi eziningi ezidingekile kuzo kuzo konke ukuphuma kwesikhumba. Ukuzibiza izikhathi zokulwa (PMT) kusenza ukuthi izikhumba zilwazi ngokungafanele, ukungabikho kwezikhumba, nokufa kahle kwezikhumba emkhaya. Ukubheka okuphelele—ngokusebenzisa izikhumba zokubheka isitha noma izikhumba zokubheka isitha esizihlukanayo—kunconywa kakhulu, ikakhulukazi ekhaya elincane kwezikhumba (isibonelo, izindawo eziphakanyisiwe noma izinyango eziphakanyisiwe). Kusenziwa kuphela ukubheka okuphelele kwezikhathi zokulwa (PMT) ukuthi kubhekwe ukuthi izikhumba zilwazi ngokuphelele nezikhumba zokulwa ngokuphelele.

Izivinini zezinhlobo zokulwa ezingaphambili ezinconywa ukuthi zihlale kuzo izikhumba zokulwa ngokuphelele kwezikhumba zokulwa ngokuphelele.

Izinhlobo zokulwa zokulwa: ubude bezikhumba, ubukhulu, ubude bezikhumba, nokushaya kwezikhumba kwezikhumba

Ukukhanya kwezinto ezihlukene kubhekisele kusukela kungaphi umkhawulo wokufaka nokugcina umthelela ngokuphatha kwemithombo. Izinyathelo ezenzima okanye eziphakeme kakhulu kuzodinga isikhathi eside sokuhlala emfurnisini ukuze kufikwe ekuphakameni kwe-PMT. Ukuthenga kwezinyathelo ngokuphelele kuhlinzekile ukuthumela umthelela ngokuphatha—kunciphisa ubungakanani ngu-40%—futhi kudinga ukuthinteka okuphambili komphathi okungapheleli noma ukuphakama kwezimfurnisi ukuze kubhekiselwe. Ngokwesibonelo, ngalokho okunye kwe-1% kokuphakama kwezindawo zokuhlala kwezinyathelo kuyabiza isikhathi sokuhlala esidingekayo ngokuphakama kwe-30 sekondi kusukela kwezinyathelo eziphakeme kakhulu. Kuya kudinga ukuthinteka komphathi kahle: ukuphakama okungapheleli kwe-5 ft/min kusho ukuthi kungafika kwezinyathelo eziphakeme kakhulu noma ezenzima kakhulu.

Ukuthinta kwezinyathelo: isitayile vs. iyaluminiyam vs. izinkulungwane zezinci zokuphatha kumthelela

Ukuthi isibonelo senzima sikhula kakhulu kusinika umphumela omuhle kwenkqubo yokugcina. Ukuthi i-aluminum inokhula kakhulu (130–150 W/mK) kusinika ukuthi umoya ufake kahle, okuzimelela isikhathi sokugcina ngama-15–20% kulungile kune-steel (45 W/mK) noma kubizwa ngokufanayo. Ukuthi i-zinc ephathelwe ngokuphatha kwesibonelo kusinika ukuthi umoya akafike kahle kumetali emhlophe, okuzimelela isikhathi sokugcina ngama-10%. Ukuchaza kwezinye izinto zokukhula kwe-infrared kusinika ukuthi i-aluminum inokuchaza okuncane (0.04–0.06) kusinika ukuthi kufuneka kubhekwe ngokuphakeme kakhulu kulungile kune-steel (0.35–0.45) kwezinkqubo zokugcina zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo zezinkqubo......

Ukugcina Kwemithambo Nezinkinga Zokuphulukana Kwezinkqubo Zokugcina Ngokwesibonelo Sokugcina

Izinkinethiki zokugcina kwezinkotho zemithambo yezinkotho zokugcina ziyasebenza ngokulinganisa isikhathi–isilinganiso sesikhathi, okwenzelwa ngokubalwa ngokulinganisa kukaArrhenius. Lokhu kusiza abahleli ukubala ukuguqula kwesibhakabhaka phakathi kweminye imikhombolo—umsebenzi wokubonisa ukuthi i-180°C ngama-minithi amashumi elishumi nesibhotho ayisibhotho esifanayo nge-200°C ngama-minithi ayisibhotho, uma isilinganiso sokusebenza sisekhi. Ukuchazwa kwe-differential scanning calorimetry (DSC) nokuchazwa kwe-rheological kubonisa le mikhombolo emhlabeni wokusebenza. Lokhu kusiza ekwenzeni izilungiselelo zomsebenzi zokuziqasha—njengokulungisa izilinganiso zemithambo engeyinkulu noma ukuguqula ubude bempilo—ngaphandle kokukhupha ubuhle bokufaka.

Kodwa, ukusuka kwindawo yokugcina okuhle kubika izimpawu ezithile. Ukugcina okungafanelekile kuthula umkhakha wokugcina okungaqondi, okuzosiba ukungabikho kwezinkqubo zokugcina, ukuncanyisa ukuphatha ngokulahla, nokuncanyisa ukukhathazeka kwemithi. Ukugcina okungafanelekile kuthula umkhakha ngokugcina kwezinkqubo zokugcina ngezibonelo zokugcina nokufinyelela kwezibonelo, okuzosiba ukuthi umkhakha ubheke kakhulu, ukuthi kubhekwe kakhulu, nokuphela ukuthi kungabikho ukuthi kubhekwe kakhulu. Izimpawu zokusebenza ezingaphansi—kunye nezimpawu zokugcina, izibonelo zokugcina, nokuthi kubhekwe kakhulu—zizokwenzwa ngokungafanelekile kokugcina kwezinkqubo zokugcina noma ukusuka kwezindawo zokugcina. Ngoko ke, ukuphatha okuhle kwezinkqubo zokugcina kuyisisekelo sokugcina kwezinkqubo zokugcina noma ukusuka kwezindawo zokugcina—kunye nokugcina kwezinkqubo zokugcina ngokujwayelekile kwezinkqubo zokugcina noma ukusuka kwezindawo zokugcina. Lokhu kusiza ukuthi umkhakha uzobona ukuthi kubhekwe kakhulu, ukuthi kubhekwe kakhulu, nokuthi kubhekwe kakhulu.