Page 16 - Curriculum Visions Dynamic Book

Ironing, permanent, and durable-press
finishing
Many fibres resist changes of shape when dry but shrink and lose their straightness when wet. That is why washed materials often shrink, and why they dry to a creased finish. Sometimes the pleats and other features carefully put into new clothing will drop out on washing.
All of these changes are problems. There are two ways to overcome them. Fibres are quite difficult
to change when they are cool, but at a particular temperature they will change shape quite easily. Getting to a temperature high enough is the purpose of ironing. Each fibre has its own temperature, which is why an iron has many temperature settings.
Ironing is a temporary way of improving the finish of a fabric. There are more permanent ways of getting
a finish. The finish can be put into the fabric at a high melting point. Just as there is a temperature for ironing, there is also a temperature at which some artificial fibres can be changed permanently. To be useful, it has to be applied to fibres that can be heated way above normal washing and ironing temperatures yet still not melt or
(Above and below) Ironing is important, but it only works until the fabric becomes moist again. This often happens unnoticed when sweat soaks into the fabric.
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