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1 Complete the statement according to the text.

Composite materials practically always have brilliant properties …

a) because they possess best properties of different materials.

b) to meet the needs of modern engineering.

c) as they are metal matrix composites.

2 Define, what statement is true to the text.

a) People use composites because they are reinforced by plastic.

b) Composites are widely used because of their unique mechanical and physical properties.

c) Composite materials are applied only in turbine compressor blades, bearings and pressure vessels.

3 Answer the question:

Why are composite materials so vitally necessary to people?

a) Composites can replace all other materials.

b) Composites are very cheap and very abandon in nature.

c) Composites are very important because the fields of their applications are numerous from heavy duty bearings, compressor blades pressure vessels and spacecrafts to insulations, filters, fiber optics.

BUSINESS ACTIVITY

Complete the dialogue:

Secretary: “I’m sorry, Mr. Brown is busy at the moment. Tell me, please, your telephone number. Mr. Brown will call you later”.

Speaker: “_______________”.

Of course. Double two-nine-three-six-four-five.

I’m not going to wait.

He can’t make me wait!

I’ll never call again.

Text 4 Plastics

Plastics have an ever-widening range of uses in both the industrial and consumer sectors. Plastics are produced by polymerization process: bulk polymerization, solution polymerization and interfacial polymerization. Chemical additives are often used in plastics to produce some desired characteristic. For instance, plasticizers make a polymer more flexible, lubricants reduce problems with friction and pigments add color. Many plastics are manufactured as composites. This involves a system where reinforcing material (fibres made of glass or carbon usually) is added to a plastic resin matrix. Plastic foams, which are composites of plastic and gas, offer bulk with low weight.

Plastics shaping and finishing techniques depend on three factors: time, temperature, flow (deformation).

One of the most widely used operations is that of extrusion. Extrusion products such as pipes are produced by pumping a plastic through a die or shape. Other operations of plastics manufacturing are extrusion blow moulding, injection moulding, compression moulding, transfer moulding. Some plastics first pressed into shape then sintered – exposed to extremely high temperatures that bond it into a cohesive mass without melting it.

As for ways of usage – the building industry is a major consumer of plastics including packaging plastics. High-density polysthene (HPDE) is used for pipes. PVC (polyvinyl chloride) is used in sheets for building materials and similar items. Many plastics are used to insulate cables, wires; and polystyrene in the form of foam serves as insulation for walls, roofs. Roofing, door, window frames, mouldings, hardware – are other plastic items. Fuel lines, pumps, electronic devices interior paneling, seats, car bodies, sports equipment are also examples of plastics products.

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