Dawb, ci, yooj yim, thiab ntshiab, cim purity.
Ntau tus neeg nyiam cov khoom dawb, thiab cov khoom siv feem ntau yog ua dawb. Feem ntau, cov neeg uas yuav khoom dawb los yog hnav khaub ncaws dawb yuav ceev faj kom tsis txhob pub dawb kom muaj stains. Tab sis muaj ib zaj nkauj uas hais tias, "Nyob hauv lub ntiaj teb tam sim no, tsis kam mus ib txhis." Txawm hais tias koj siv zog npaum li cas los tswj cov khoom no los ntawm kev ua qias tuaj, lawv yuav maj mam tig daj rau lawv tus kheej. Rau ib lub lim tiam, ib xyoos, lossis peb xyoos, koj hnav lub mloog pob ntseg mus ua haujlwm txhua hnub, thiab lub tsho dawb uas koj tsis tau hnav hauv lub wardrobe ntsiag to tig daj ntawm koj tus kheej.
Qhov tseeb, yellowing ntawm cov khaub ncaws fibers, elastic khau khiab, thiab lub hnab yas headphones yog ib qho kev tshwm sim ntawm polymer aging, hu ua yellowing. Yellowing yog hais txog qhov tshwm sim ntawm degradation, rearrangement, los yog cross-linking nyob rau hauv lub molecules ntawm polymer cov khoom thaum lub sij hawm siv, tshwm sim los ntawm tshav kub, lub teeb hluav taws xob, oxidation, thiab lwm yam, uas ua rau cov tsim ntawm ib co xim ua hauj lwm pab pawg neeg.
Cov pawg xim no feem ntau yog carbon ob daim ntawv cog lus (C = C), pawg carbonyl (C = O), imine pawg (C = N), thiab lwm yam. Thaum tus naj npawb ntawm conjugated carbon ob daim ntawv cog lus nce mus txog 7-8, lawv feem ntau tshwm daj. Feem ntau, thaum koj pom tias cov khoom siv polymer pib daj, tus nqi ntawm yellowing yuav nce. Qhov no yog vim qhov degradation ntawm polymers yog cov tshuaj tiv thaiv kab mob, thiab thaum cov txheej txheem degradation pib, kev tawg ntawm cov saw hlau molecular zoo li domino, nrog rau txhua chav poob tawm ib los ntawm ib qho.
Muaj ntau txoj hauv kev kom cov khoom siv dawb. Ntxiv titanium dioxide thiab fluorescent whitening agents tuaj yeem txhim kho cov nyhuv whitening ntawm cov khoom, tab sis nws tsis tuaj yeem tiv thaiv cov khoom los ntawm yellowing. Txhawm rau kom qeeb lub yellowing ntawm polymers, lub teeb stabilizers, lub teeb absorbers, quenching agents, thiab lwm yam tuaj yeem muab ntxiv. Cov hom additives no tuaj yeem nqus tau lub zog nqa los ntawm ultraviolet lub teeb nyob rau hauv tshav ntuj, coj cov polymer rov qab mus rau lub xeev ruaj khov. Thiab cov tshuaj tiv thaiv thermal oxidants tuaj yeem ntes cov dawb radicals tsim los ntawm oxidation, los yog thaiv qhov degradation ntawm polymer chains kom tshem tawm cov tshuaj tiv thaiv ntawm polymer saw degradation. Cov ntaub ntawv muaj lub neej ntev, thiab cov khoom ntxiv kuj muaj lub neej ntev. Txawm hais tias cov additives tuaj yeem ua rau qeeb tus nqi ntawm polymer yellowing, lawv lawv tus kheej yuav maj mam poob thaum siv.
Ntxiv nrog rau kev ntxiv cov tshuaj ntxiv, nws kuj tseem tuaj yeem tiv thaiv cov xim daj los ntawm lwm yam. Piv txwv li, txhawm rau txo kev siv cov ntaub ntawv hauv qhov kub thiab txias qhov chaw sab nraum zoov, nws yog ib qho tsim nyog yuav tsum siv lub teeb absorbing txheej rau cov ntaub ntawv thaum siv sab nraum zoov. Yellowing tsis tsuas yog cuam tshuam rau cov tsos, tab sis kuj yog lub teeb liab ntawm cov khoom siv tshuab ua haujlwm degradation lossis tsis ua haujlwm! Thaum cov khoom siv hauv tsev tau daj, cov khoom siv tshiab yuav tsum tau hloov sai li sai tau.
Post lub sij hawm: Dec-20-2023