1.Yuav ua li cas oxidation (degradation) ua rau pulverization?
Oxidation/Degradation (Internal Chemical Changes):
Cov resin nyob rau hauv cov xim -coated coil (xws li polyester) muaj kev hloov tshuaj lom neeg thaum raug kev sib xyaw ua ke ntawm ultraviolet (UV) hluav taws xob, tshav kub, oxygen, thiab ya raws sab nraum zoov rau ncua sij hawm ntev- txheej txheem hu ua "daim duab- oxidative degradation" lossis "thermal oxidative degradation."
Cov txheej txheem no cuam tshuam cov resin molecular chains thiab tshuaj bonds, ua rau txo qis ntawm nws cov℃ntawm polymerization thiab xoob, nkig qauv.
Poob Adhesion (Critical Turning Point):
Cov resin ua raws li "kua nplaum" nyob rau hauv txheej, khov kho cov xim pigment ua ke thiab adhering lawv mus rau lub substrate.
Raws li cov resin degrades vim oxidation, nws lub zog nplaum maj mam tsis muaj zog.
Chalking (External Physical Manifestation):
Thaum cov resin lub zog nplaum tsis muaj zog mus rau qhov chaw uas nws tsis tuaj yeem thaiv thiab txhim kho cov xim xim, cov xim xim sab nrauv pib xoob thiab nthuav tawm.
Raws li kev cuam tshuam ntawm sab nraud quab yuam xws li cua, nag, thiab kev sib txhuam, cov xim xoob xoob no tshem tawm ntawm cov txheej txheej, tsim cov txheej txheem yooj yim so - tawm hmoov. Qhov no yog qhov peb pom tias yog "chalking."
2.Dab tsi yog cov yam ntxwv ntawm cov txheej txheem pulverization?
Cov xwm txheej maj mam: Chalking tsis yog tam sim ntawd; nws yog ib tug gradual txheej txheem. Feem ntau, poob ntawm gloss thiab discoloration / daj tshwm sim ua ntej, ua raws li los ntawm theem chalking.
Pib los ntawm Nto: Txij li thaum ultraviolet (UV) lub zog siab tshaj plaws, degradation thiab chalking ib txwm pib ntawm txheej txheej txheej txheej, maj mam nce mus rau txheej txheej.
Chalking Rate yog cuam tshuam los ntawm ntau yam:
Resin Hom: Ordinary polyester (PE) yog feem ntau ua rau chalking; siab- huab cua- tiv taus polyester (HDP) thiab silicone- hloov polyester (SMP) muaj zog tiv taus chalking; PVDF (fluorocarbon) coatings nthuav tawm qhov zoo tshaj plaws tiv thaiv chalking, tswj lawv txoj kev ncaj ncees txawm tias tom qab ntau xyoo ntawm kev siv sab nraum zoov.
Pigment Quality: Siv siab -zoo, ruaj khov pigments (xws li inorganic pigments thiab huab cua zoo heev-cov pigments tiv taus) tuaj yeem ncua sijhawm chalking.
Ib puag ncig tej yam kev mob: Muaj zog UV hluav taws xob, kub thiab av noo, thiab corrosive industrial lossis marine cua ua kom cov txheej txheem chalking.
Txheej Thickness: Muaj txheej txheej thickness muab lub sij hawm ntev degradation tsis.
3.Dab tsi yog cov cim qhia ntawm txheej chalking?
Poob gloss, fading (xim discoloration), yellowing: Oxidative degradation pib ntawm txheej txheej, thiab cov qauv ntawm cov resin thiab pigments hloov.
4.Dab tsi yog cov yam ntxwv ntawm txheej chalking nyob rau hauv nruab nrab theem?
Nws pib hmoov; pom cov hmoov zoo tuaj yeem pom thaum rub nrog tus ntiv tes lossis daim ntaub.
Lub hauv paus ua rau yog tias cov resin nto tau degraded loj heev, poob nws lub zog nplaum, thiab cov xim pigment tau raug thiab pib poob.
5.Dab tsi yog cov yam ntxwv ntawm txheej chalking nyob rau theem tom ntej?
Kev hnyav hnyav, nthuav tawm cov primer lossis substrate, tuaj yeem ua ke los ntawm kev tawg thiab tev.
Cov txheej txheem kev tiv thaiv yog qhov tseem ceeb poob, tso cai rau corrosive media (dej, oxygen, ions) ncaj qha mus tua cov hlau hauv qab.