Technical materials.

In this unit, we will see how man has utilized natural resources to extract raw materials that are transformed into materials of technical use and finally through manufacturing has obtained technological products. Look at the process in this diagram: 

Technological products.

 The technological products are the objects manufactured or elaborated by men from materials of technical use to satisfy their needs and to improve their quality of life. There are many examples we use every day: books (made with paper), bottles (made with glass or plastic), tables and chairs (manufactured with wood, steel, aluminum or plastic), etc. 

 Following the same classification that we have used for the materials we will have: 

• Wood products: furniture, doors, windows, paper, cardboard, etc. 

• Plastic products: bottles, pens, folders, containers, etc. 

• Metallic products: machines, cars, structures, tools, etc.

• Stone products: glass bottles, plaster, marble tiles, etc. 

• Ceramic products: tiles, bricks, dishes, etc. 

• Textile products: pants, jackets, coats, clothes, bedspreads, tablecloths, curtains, 

The materials of technical use are the materials that are obtained from the raw materials by the process called transformation and that are useful and have value for the man. Some of the technical properties of the materials are as follows: 

Raw materials are materials that are extracted directly from nature (natural resources) and are useful and valuable to man. The raw materials are classified according to their origin in three large groups: animal, mineral and plant

Classification of materials according to their origin If we use the criteria of origin, we find two groups:

•  Natural materials, which are found in nature. 

• Transformed materials, which have a chemical modification process before being used to manufacture the technical objects. 

Natural resources are those resources that are found in nature without man modifying them, but are useful and valuable because they allow the development and well-being of society. Examples: trees, forests, mines, quarries, oil and natural gas wells, animals, etc 

• Raw materials of animal origin: they are obtained from animals that are raised. Some examples of this type of raw materials are: wool (from sheep), silk (from silkworm), skins (from cow), etc. 

• Raw materials of plant or vegetable origin: are obtained from plants, by harvesting after planting. They belong to this type: cotton (from the cotton plant), wood (from trees), flax (from the flax plant), cork (from cork bark), etc. 

• Raw materials of mineral origin: are extracted from quarries, mines, or wells. Minerals are sand, marble, iron ore, copper ore, oil, slate, etc 

Classifications allow us to group many elements into different groups. Classifying allows us to organize and manage knowledge. To make classifications, a criteria is required. A criteria is something that allows us to select the group to which each element belongs. To classify materials for technical use we will use three criteria:

1.  According to its origin.

2. According to its nature.

Classification of materials according to their origin. If we use the criteria of origin, we find two groups: 

• Natural materials, which are found in nature. They can be lightly treated or adapted.

• Transformed materials, which have a chemical modification process before being used to manufacture the technical objects. 

Classification of materials according to their nature. If we use the criteria of their nature, we can find the following groups: 

• Wood materials: are obtained from the trees. They can be two types: 

• Natural woods (pine, oak, beech, cherry, etc.) 

• Artificial or man-made woods (plywood, chipboard, fiberboard). 

• Plastic materials: obtained from petroleum. Ex: cellophane, PVC, etc.

• Metallic materials: are obtained from metallic minerals. There are two types: 

• Those containing iron or ferrous (iron, steel and cast iron) 

• Those that do not contain iron or non-ferrous (aluminum, copper, silver, etc)

• Stone materials: they are obtained from the minerals of the rocks. Examples: glass, plaster, cement, slate, etc.

• Ceramic materials: obtained by baking clay at high temperatures in an oven. Examples: ceramics and porcelain 

• Textile materials: there are of two types:

• Natural: they are obtained from animals and plants such as wool, silk, cotton or linen. 

• Artificial: they are obtained by industrial transformations, mainly of the petroleum, like the threads of nylon, the lycra or the polyester.