Tear a sheet of paper slowly and look closely at the torn edge. Can you see tiny, fuzzy threads sticking out? Those are fibres, and they are the secret of paper.
Paper is made of plant fibres
Plants are made of long, thin fibres of a material called cellulose. When these fibres are mixed with water and then dried flat, they cling to each other and form a sheet. Most paper today is made from wood. Long fibres from trees such as pine make paper strong, while shorter fibres from trees such as eucalyptus make it smooth.
From log to sheet
In a paper mill, the journey goes like this:
- Logs are stripped of their bark and cut into small wood chips.
- The chips are cooked or ground to separate the fibres. The mushy mixture is called pulp.
- The pulp is washed and often bleached (made whiter).
- Lots of water is added, and the watery pulp is spread on a moving wire mesh. Most of the water drains away.
- Rollers squeeze out more water, and steam-heated cylinders dry the sheet.
- The paper is wound into huge reels called jumbo rolls, which are later cut into smaller sheets.
Paper without trees
Paper does not always need trees. Tamil Nadu Newsprint and Papers Limited (TNPL) uses bagasse, the leftover of sugarcane, as its main raw material. It has been described as the largest bagasse-based paper mill in the world.
In Sanganer, near Jaipur in Rajasthan, paper is made by hand from cotton cloth waste. The waste is soaked and turned into pulp, which is lifted out on mesh trays. The wet sheets are stacked with thin muslin cloth between them, pressed, and hung on lines to dry. Some makers mix in grass or flower petals, such as marigold, for colour and texture. Sanganer is also home to the Kumarappa National Handmade Paper Institute.
A word with a story
The word “kagaz”, used for paper in many Indian languages, comes from Persian.
Try this: Tear a page of newspaper and a page from an old notebook. Look at the torn edges. Which one shows longer, fuzzier fibres? Now hold each one up to a window. Which lets more light through?