What it shows
Paper is made of plant fibres, and these fibres can be soaked, mashed and pressed into new sheets. Recycling saves trees and water.
The science
Paper is a mat of cellulose fibres from wood or other plants. When soaked, the fibres separate. When spread on a screen, the water drains and the fibres stick back together by hydrogen bonding as they dry. Recycling uses far less energy and water than making paper from wood. Each time paper is recycled the fibres get shorter, so it can be recycled only a few times.
Materials
Cost: free. Many items come from home or from waste; spare parts such as LEDs, motors and wire are in the store.
- Old newspaper torn into small pieces
- A bucket of warm water
- A wire mesh frame or an old mosquito net stretched on a wooden frame
- A tray larger than the frame
- A sponge and a cotton cloth
- A hand blender or a wooden masher (adult only)
- Heavy books
Safety
For this project: An adult must use the blender and handle hot water. Keep your hands dry around electrical items.
Never use mains electricity: power models with cells, batteries or a low-voltage adapter. Sharp and hot tools, flames and lab chemicals need an adult or your teacher beside you. Keep magnets, button cells and small parts away from young children, and wash your hands after making.
All the safety rulesStep by step
8 steps. Do them in order, and test each part before you go on to the next. Write what you notice in a notebook as you go.
Tear the newspaper into pieces of about 2 cm and soak them in warm water overnight.
An adult blends the soaked paper into a smooth pulp using a blender or masher.
Pour the pulp into a tray with extra water so it is like thin porridge.
Slide the mesh frame under the pulp and lift it so a thin even layer rests on the mesh.
Let water drain and press with a sponge from the top to remove more water.
Turn the frame over onto a cotton cloth and lift it away to leave the wet sheet.
Press it between cloths under heavy books for a day.
Dry in the shade, peel off and use it to write a card.
What you should see
A rough but usable sheet of recycled paper, about 20 cm by 15 cm, ready for writing.
Viva questions
A teacher or a judge will ask how it works. Try to answer each question before you open it, then compare.
1What is paper made from?
Cellulose fibres from plants.
2Why does recycling save trees?
It uses old paper in place of fresh wood pulp.
3What holds the fibres together?
Hydrogen bonds as the sheet dries.
4Why can paper not be recycled forever?
The fibres shorten and weaken each time.
Take it further
Add dried flower petals or turmeric to the pulp and make seed paper.
Change one thing, measure what happens, and add a table or chart of your readings: that is what turns a model into your own investigation.
Free ebooks for this project
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