Why is old paper yellowing?

If you notice, you will see some old books will have yellow reclining paper. Do you think books of the past have such yellow paper material?

In fact, when they were new, the books of those books could be as white as the books we just bought. But over time, they will turn yellow (your book will probably turn yellow after 20 years). So why does paper fall yellow over time? We will find the answer together.

History has always attracted me. I enjoyed learning about the development of the world over the years, many times. They are wonderful and majestic. I feel grateful to historians and authors of books that write about important events in our history. As a result, we can understand the development and transformation process of the beautiful world today, and also understand how society has evolved through the stages. I am addicted to history - probably because of my grandfather's influence. He has a lot of books on world history and he loves to show me the magnificent history stories in his books. He was passionate about talking about battles, heroic victories and special moves of the country.

Yellow paper over time.

Through my grandfather's pages, I could travel through time. It really pulls and attracts me to the story of how the earth has evolved through time and changes in the world through many stages of history. And another thing made me curious: it was the change of my grandfather's books over time. Yes, the historical content in the books is still there, not changing even a little, but the pages have turned from white to yellow. The letters in the book become increasingly difficult to read.

So why is the paper yellowing? And how can we stop yellowing books over the years?

Learn about paper

Paper is made from many types of wood. Wood mainly consists of two types of polymers: cellulose and lignin . It is lignin that makes paper turn yellow . Lignin is naturally colored black, and is a substance that makes wood hard and healthy. Lignin is oxidized when exposed to sunlight and when exposed to air. And this makes it break down into many phenolic acids and turn yellow.

How to make paper yellow?

Today, paper is formed from wood that removes acid. To do this, paper mills had to separate lignin from wood components. This makes the current paper material more durable, longer life expectancy compared to the previous paper material that still includes lignin. To produce paper without lignin, we need to add a chemical process to the production process to remove lignin from the wood, or in a more understandable way, the production of paper - no - lignin is expensive. more than usual paper production way.

And if you notice, you will notice that the newspaper is very easy to yellow in a short time. Why is that?

The newsrooms have chosen traditional paper production methods (including lignin) to save printing costs.

Because they are manufactured and the purpose of newspapers is to read short-term news, not the preferred content for long-term retention. Therefore, the newsrooms have chosen traditional paper production methods (including lignin) to save printing costs.

Going back to books with paper-covered materials - including the old-fashioned lignin: is there any way to protect them from the yellowing process over time as a natural law?

Because they still contain lignin, they are still somewhat yellow, not white. We can only limit this by keeping those ancient favorite books in a place with little acidity. Or to put it more closely: leave them in dry places, avoid the sun and, of course, no insects (our precautionary books are chewed). In doing so, our history will remain clear, easy to read and survive as long as possible.

This is also a way to store historical book pages at large libraries. There, they are protected in an ideal environment, perfect temperature and humidity, helping to protect the heroic history of the nation over time and circulating to the younger generations in the future.