Australian_Science_Illustrated_Issue_52_2017

JØRGEN STAMP

How is Kevlar made?

Two solutions with individual molecules are mixed

to produce polymers. The polymers are linked by

powerfully-bonding hydrogen compounds.

The liquid with polymers is sent through a

spinneret, uniting individual fibres into yarn.

A chemical bath hardens the yarn.

The Kevlar yarn is stretched into the full length of

the fibres via a roller system. The process aligns

the fibres, making the material stronger.

The fibres are woven into Kevlar cloth. The material

is five times stronger than steel and used for making

bulletproof vests, puncture-free tyres, etc.

Kevlar is a strong synthetic fibre used in bulletproof vests. The material was

invented by US chemist Stephanie Kwolek in 1965, when she was aiming to

invent a lighter, but still strong material to replace steel in car tyres.

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2

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KEVLAR CLOTH

BULLETPROOF

VEST + TYRES

ROLLERS

POLYMERS

SPINNERET

20 | SCIENCE ILLUSTRATED

ASK US

Adults may temporarily

sleep with their eyes open.

Can humans sleep with their eyes open?

The eyes can be open during ordinary sleep, but

the sleeping person is unconscious and cannot see

anything. The cause is typically that a nerve

function in the eye region fails, making the eyelids

slide open. The condition can occur temporarily in

healthy people, and for unknown reasons, it is

most common among small children, who grow

out of it. Sleeping with open eyes can also be a

permanent condition among adults caused by

blood clots in the brain or facial paralysis. The

phenomenon does not harm the visual organ, but

the eyes can dry out from being open all night.

SHUTTERSTOCK

STATE OF SLEEP WITH

OPEN EYES:

Confused agitation: Brief

awakening from deep sleep.

The eyes are open, but do not

see anything.

Sleepwalking: Actions made

because a small portion of the

brain is awake during sleep.

Sleep terror: Reaction during

deep sleep with unconscious

screaming and anxiety.

THE^4 STEPS