Dawb, kaj, yooj yim, thiab ntshiab, cim kev coj dawb huv.
Coob tus neeg xws li cov khoom dawb, thiab cov neeg siv khoom lag luam feem ntau ua rau dawb. Feem ntau, cov neeg yuav yuav cov khoom dawb lossis hnav khaub ncaws dawb yuav ceev faj kom tsis txhob cia tus dawb tau txais yam stains. Tab sis muaj cov lyric uas hais tias, "Nyob rau hauv no tam sim no ntug, tsis kam mus ib txhis." Tsis muaj teeb meem ntau npaum li cas koj muab tso rau hauv kev tswj cov khoom no los ntawm kev qias, lawv yuav maj mam tig daj rau lawv tus kheej. Rau ib lim tiam, ib xyoos, lossis peb xyoos, koj hnav lub tsho rau lub ntsej muag ua haujlwm txhua hnub, thiab lub tsho dawb kom koj hnav hauv lub wardrose uas ntsiag to ntawm koj tus kheej.
Qhov tseeb, yellowing ntawm cov ris tsho cov fibers, elastic khau chav, thiab yas hau taub hau lub thawv yog kev manifestation polymer kev laus, hu ua yellowing. Yellowing hais txog qhov tshwm sim ntawm kev ua tsis raws kev ua tsis ncaj, lossis hla kev sib tw thaum siv, oxidation, thiab lwm yam kev tsim muaj qee pab pawg muaj xim.
Cov pab pawg muaj cov xim muaj zog feem ntau yog cov pa roj carbon monoxide feem ntau (c = c), carbonyl pawg (c = i) pawg (c = n), thiab lwm yam. Thaum tus naj npawb ntawm conjugated cov pa roj carbon carbon pupbon muab obliv tau mus txog 7-8, lawv feem ntau tshwm daj. Feem ntau, thaum koj pom tias cov khoom lag luam polymer tau pib tig daj, tus nqi ntawm kev daj ua daj ua rau nce. Qhov no yog vim tias qhov kev tsis txaus siab ntawm cov polymers yog cov txheej txheem kev tawm tsam, thiab ib zaug cov kab ke ntawm cov roj av yog zoo li lub domino, nrog txhua chav tsev poob ib qho ntawm ib qho.
Muaj ntau txoj hauv kev los khaws cov khoom dawb. Ntxiv Titanium Dioxide thiab cov fluorents cov neeg sawv cev tuaj yeem txhim kho cov tshuaj ntxuav hniav dawb, tab sis nws tsis tuaj yeem tiv thaiv cov khoom ntawm yellowing. Txhawm rau qeeb ntawm cov yellers ntawm cov polymers, lub teeb ci ntsa iab, lub teeb nqus, cov neeg sawv cev, thiab lwm yam tuaj yeem ntxiv. Cov hom kev sib ntxiv no tuaj yeem nqus lub zog nqa los ntawm ultraviolet teeb nyob rau hauv lub hnub ci, nqa cov polymer rov qab mus rau lub xeev ruaj khov. Thiab anti thermal oxidants tuaj yeem ntes cov dawb radicals tsim los ntawm oxidation, los yog thaiv qhov kev ua kom tsis txaus siab ntawm cov tshuaj tiv thaiv cov saw ntawm polymer kev ntsuas. Cov ntaub ntawv muaj lub neej, thiab cov quav ntxiv kuj muaj lub neej. Txawm hais tias Additives ntxiv tuaj yeem ua kom qeeb tus nqi ntawm polymer daj, lawv lawv tus kheej yuav maj mam thaum siv.
Ntxiv nrog rau kev ntxiv ntxiv cov quav, nws tseem tuaj yeem tiv thaiv cov xim daj polymer los ntawm lwm yam. Piv txwv li, txhawm rau txo cov khoom siv hauv qhov kub thiab txias thiab qhov chaw sab nraum zoov ib puag ncig, nws yog ib qho tsim nyog los siv lub teeb nqus cov txheej txheem rau cov khoom siv thaum siv lawv sab nraum zoov. Yellowing tsis yog cuam tshuam rau cov tsos, tab sis kuj ua haujlwm ua lub teeb liab ntawm cov khoom siv xws li kev ua haujlwm lossis tsis ua haujlwm! Thaum cov ntaub ntawv tsim vaj tse tau yauv nyom, hloov chaw tshiab yuav tsum tau hloov sai li sai tau.
Lub Sijhawm Post: Dec-20-2023