Natural Sciences and TechnologyGrade 5

Term 2: Matter and MaterialsProcessed Materials

(PPT 1)

Topic 4Processed Materials

Properties and uses

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

Processed materials

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

Materials that have been changed from a raw material to another type of material.This is done by combining materialsThere are many different reasons for processing materials.We do it mostly so that they are more useful to us in their changed state (they smell, look, taste, feel different).The combined materials are useful for a specific purpose because of their properties.

Processed materials

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

Processed materials

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

Properties of plastic

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

• Alexander Parkes created the first man-made plastic.• He publicly demonstrated it at the 1862 Great

International Exhibition in London.• The material, called Parkesine, was an organic material

that was obtained from cellulose.• Once heated, it could be moulded.• It retained its shape when cooled.• Today, plastic material is any of a wide range of

synthetic or semi-synthetic organic solids that are mouldable.

Properties of plastic

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

See how many things you can list that are made out of plastic.

Plastic has many useful properties-• recyclable (but not all forms of plastic)• waterproof• prevents wastage (can be washed & re-

used)• it can be easily shaped and moulded

Plastic products

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

Harmful properties of plastic

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

•Some water bottles contain a harmful industrial chemical called BPA (Bisphenol A).•If these are bottles are left in the sun and we drink the water, we can become ill.•Disposing of mineral water bottles is a big problem for the world.

Can you think of ways to reuse these bottles?

Properties of wool

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

•Wool comes from sheep.•It forms a warm covering. •Wool is used to make clothes, blankets, etc.•When wool is processed into balls of wool, it is suitable for knitting and weaving.

Properties of clay

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

• Clay is very fine particles of dirt which float in a stream or river and then sink to the bottom, where they press on each other and stick together

• You generally find clay along the banks of a river or stream.

Properties of clay

Gr 5 Natural Sciences and Technology – Term 2, Topic 4

• Clay is easy to mould when it is wet.• It sticks together in its moulded form when it is dry. • It lasts for a very long time when heated in a kiln. • Clay can also be glazed.