My Science School

"Wash your hands," your mum says. As you squeeze the liquid soap into your hands, you wonder, "Where's the dirt?" Some flakes of dirt may be too tiny for you to see. But the soap surrounds, "captures," and breaks up the dirt into smaller bits. Once the dirt is broken up, water can rinse it away.

Soap is made by blending animal or vegetable fat and a very strong chemical called lye. Heating this over a hot fire causes a thick, hot liquid to form. Colourings and fragrances are added. Then the mixture is dried.

A machine slices the dried soap into chunks that look like noodles. To make liquid soap, the soap noodles are blended with water and heated again. To make bar soap, the noodles are shaped into "logs" by another machine. These logs are sliced, like a loaf of bread. The "slices" are pressed into shapes and wrapped-then they are bars of soap!

 

Picture Credit : Google

When the Chinese made paper 2,000 years ago, they used garbage. Rags and old fishing nets, along with plants, were boiled in a huge tub of water. They stirred the mixture and beat it into a pulp. They let the water drain and then pressed the pulp. When it dried, it was a sheet of paper. Try making your own!

You Will Need:

• used paper or newspaper


• leaves and flowers (optional) 480 ml to 960 ml hot water


• a bowl


• a hand whisk or fork


• a baking tray 23 x 33 cm


• a rolling pin


• newspaper


• paper towel


• a paper form (a piece of wire mesh with folded


• edges or window screening in an


• embroidery ring) an old cloth towel


• spray starch

What to do:

1. Tear the used paper and newspapers into pieces about the size of postage stamps.

2. Drop them into the bowl and add hot water. Beat the mixture until it is smooth. There should be no big pieces left. The pulp should be thick, but thin enough to pour, like a porridge.

3. Pour the mixture into the baking pan. Then dip the paper form into the pan, sliding it under the mixture. More the mesh around to get a thick, even layer of mixture on top. You may want to use your fingers to spread the mixture out.

4. Use both hands to lift the paper form straight up out of the pan and let the water drain away. If you like, add a design. Place leaves and flowers on top of the pulp that's on the paper form.

5. Lay the paper form between the pages of a newspaper. Place paper towels on top of the pulp. Then roll a rolling pin over the newspaper to blot water from the pulp.

6. Turn the paper form over onto an old cloth towel. Gently remove your homemade paper from the paper form. Let your paper dry on the towel for a day. Spray starch can be used to help "set" the paper and make it easier to write on.

 

Picture Credit : Google

Paper is one of the greatest inventions, Imagine a world without it. There would be no books, magazines, newspapers, or boxes. How would we send letters to friends or do homework?

People make paper from trees. The logs go to a paper mill, where the bark is removed. The wood is then chopped into small pieces about the size of your fingernail.

The wood chips are cooked in steam and chemicals to make a pulp. Sometimes used paper and rags are added. Then the pulp is washed to remove the chemicals and other unwanted materials.

Machines beat the pulp to separate the wood fibres. Sometimes colouring is added at this stage.

Next, the pulp goes to a paper-making machine. It is poured onto a wire-mesh belt that removes the water. After that, rollers squeeze the paper into sheets and dry it.

Finally, the paper goes through heavy rollers that iron it smooth.

Recycled paper is made using shredded newspapers and other used paper products. It is added to the wood chips during the pulp stage, making up 25 to 50 percent of the paper pulp.

 

Picture Credit : Google