Page 18 - Curriculum Visions Dynamic Book

Microfibres
You have already
seen that fibre sizes vary enormously. In fact, that has a large influence on how fibres behave, for example, in how waterproof they are and how easily they breathe (let water vapour through).
Some new synthetic fibres are made with
a very small diameter. The fibre, when woven, is still open enough to allow moisture to flow through, but it is fine enough to prevent water getting through. Previously this could only be achieved by using special chemical treatments, for example, by coating the fabric with silicone.
There is clearly much more development possible in fibre technology, and in time it may allow fibre manufacture to overcome a whole raft of limitations that are still present in many fibres (see page 46).
Fabrics of microfibres keep out the wind.
(Left and below) Some synthetic
fibres, such as polyester, have a natural resistance to being made wet. That makes them suitable rainproof materials. But the waterproof qualities of polyester
are still not sufficient to keep water out because the water gets between the fibres. The traditional way to make a material waterproof is to treat it with a water- repellent chemical.
However, by making the material with microfibres, that is, fibres with an incredibly fine diameter, the finer mesh of the fabric also makes it less likely that water can pass through. In this case the material is naturally rain-resistant and does not need special surface treatment to repel water. Surface treatments on outdoor garments can make them
less able to breathe because the pores become clogged. They also tend to
wear off in time. As a result, the use of microfibres in these circumstances would make a garment more comfortable and waterproof for the length of its life.
Microfibres have the additional advantage that they keep the wind out, making the fibre better for preventing body heat loss.
Microfibres still allow water vapour to pass through.
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