Trivia of the day!
9:00 AM Edit This
Have you ever wondered why your papers turn yellow overtime? It got me wondering, for no reason yesterday, so I did a little research.
Paper is usually made up of cellulose and a polymer called lignin. This substance are found naturally in trees and their stiffness property helps trees to grow tall. The main reason that papers turn yellow is the oxidation of lignin upon exposure to light and air.
So in white paper production, much of the lignin is removed and bleaching is done to make papers pure white. Still, the small amount of lignin in papers can oxidise and turn them yellow. While for brown paperbags and cardboards, they contain a higher amount of lignin in order to make use of its stiffness property.
Now you know ;)
Paper is usually made up of cellulose and a polymer called lignin. This substance are found naturally in trees and their stiffness property helps trees to grow tall. The main reason that papers turn yellow is the oxidation of lignin upon exposure to light and air.
So in white paper production, much of the lignin is removed and bleaching is done to make papers pure white. Still, the small amount of lignin in papers can oxidise and turn them yellow. While for brown paperbags and cardboards, they contain a higher amount of lignin in order to make use of its stiffness property.
Now you know ;)
