Page 18 - 6748

7 Imagine you are presenting a product or appliance you know well to a potential client.
Describe the categories of material used to make the different parts.

III Specifying and describing properties
8a In pairs, discuss what you know about the properties of Kevlar® and how it is used.
b Read the following extract from DuPont™’s technical guide to Kevlar®. Compare the
information with your ideas from Exercise 8a.
WHAT IS KEVLAR®?
DuPont™ KEVLAR® is an organic fiber in the aromatic polyamide family. The unique
properties and distinct chemical composition of KEVLAR® distinguish it from other
commercial, man-made fibers.
KEVLAR® has a unique combination of high modulus, toughness, abrasion resistance and
thermal stability. It was developed for demanding industrial and advanced-technology
applications. Currently, many types of KEVLAR® are produced to meet a broad range of end
uses that require strong, lightweight, durable materials.
DuPont™ and Kevlar® are registered trademarks or trademarks of E.I.du Pont de Nemours
Company or its affiliates

c Find words in the text in Exercise 8b to match the following definitions.
1 toughness = the opposite of fragility
2 = resistance to damage caused by friction
3 = resistance to problems caused by temperature change
4 = long-lasting
5 = the opposite of heavy

9 a Match the automotive parts (1-5) to the descriptions (a-e).
1 drive belts a sheets inserted between parts to prevent gas or fluid leakage
2 brake pads b pneumatic envelopes in contact with the road surface
3 tyres c flexible bands used in transmission systems
4 sealing gaskets d protective barriers capable of resisting gunshots
5 bullet-resistant armour e pads pressed against discs to induce deceleration

b Read the information from DuPont™ on the following page explaining some of the
automotive applications of Kevlar®. Complete the text using the automotive parts in
Exercise 9a.

Car and truck (1) have incorporated Kevlar® into their construction because
it offers superb puncture, abrasion and tear resistance.
The high modulus and abrasion resistance of Kevlar® help (2) retain their
original shape and tension over the millions of revolutions they go through over the lifespan of a
vehicle.
The frictional forces that (3) are designed to endure take less of a toll on
those made with Kevlar® pulp. The enhanced thermal stability and inherent abrasion resistance
of Kevlar® allow them to last long and stop the vehicle safely and quietly. Kevlar® provides an
effective, lightweight(4) solution for vehicles that require protection against
ballistic attack, allowing cars and light trucks to retain most of their original handling
characteristics.
Chemical stability and thermal stability help make (5) reinforced with
Kevlar® pulp strong and durable. The galvanic corrosion resistance of Kevlar® also contributes
to improved long-term engine performance.

16