Menene dalilai na yellowing na PVC filastik?

Menene dalilai na yellowing na PVC filastik?

Yin rawaya na robobi yana nufin ɗaukar sarkar sarkar-kamar polymer kwayoyin da ke karyewa a ƙarƙashin matsanancin zafin jiki, yanayi mai oxidizing, ko ƙarƙashin aikin ultraviolet, infrared, da ƙananan ƙwayoyin cuta, waɗanda ke haifar da rarrabuwar kawuna.

Yawan yellowing na robobi na yau da kullun ya ƙunshi abubuwa masu zuwa:

1. Ultraviolet radiation

Hasken da rana ke haskakawa zuwa saman saman iska shine ci gaba da bakan tare da tsayin daka na 0.7-3000nm, wanda 300-400nm ultraviolet radiation shine babban dalilin lalacewar polymer. Kuma makamashin photons a cikin kewayon ultraviolet na 290-400nm shine 300-419kJ/E, wanda ya fi ƙarfin haɗin gwiwa na wasu nau'o'in sinadarai na yau da kullum a cikin polymers.

2. Tasirin zafi stabilizer

Matsalolin zafi daban-daban suna da tasiri daban-daban akan daidaiton haske na PVC.

Ba/Cd da organotin carboxylate mahadi (kamar maleic anhydride ester organotin stabilizers) na iya samar da wani takamaiman matakin kwanciyar hankali na UV zuwa bayanan martaba na PVC da aka yi amfani da su a waje, yayin da mahaɗin organotin mai ɗauke da sulfur (kamar sulfur Alcohol Organic tin stabilizers) yana ba da ƙarancin kwanciyar hankali. Tsayayyen haske na mai daidaita gubar di-gishiri ya fi na na'urar daidaitawar gubar uku-gishiri.

3. Tasirin tsarin antioxidant

A halin yanzu, stabilizers da masana'antun bayanin martaba na PVC ke amfani da su galibi masu daidaitawa ne. Baya ga babban fili wanda ke tabbatar da lalacewar PVC, sun kuma haɗa da tsarin lubricating, tsarin antioxidant da sauran tsarin ƙarfafawa.

Tsarin antioxidant na iya haɗawa da phenolic stabilizers da phosphite co-stabilizers. Wadannan mahadi na iya ƙunsar ƙazantattun abubuwan da ba su canza launi ba cikin sauƙi, kuma ƙari, za su iya fuskantar halayen canza launin a ƙarƙashin aikin haske, oxygen, da ruwa.