When your favourite dress or shirt shrinks in the wash, it can be devastating, especially if you followed the instructions closely. Unfortunately, some fabrics just seem to be more prone to shrinking than others – but why?
Understanding more about the science of textile fibres can not only help you prevent the shrinkage of clothing, but also might help you “rescue” the occasional garment after a laundry accident.
It’s all down to the fibres
To know more about clothing shrinkage, we first need to understand a little about how textiles are made.
Common textile fibres, such as cotton and linen, are made from plants. These fibres are irregular and crinkled in their natural form. If you zoom deeper inside them, you’ll see millions of tiny, long-chain cellulose molecules that naturally exist in coiled or convoluted shapes.
During textile manufacturing, these fibres are mechanically pulled, stretched and twisted to straighten and align these cellulose chains together. This creates smooth, long threads.
On a chemical level, there are also links between the chains called hydrogen bonds. These strengthen the fibre and the thread and make it more cohesive.
Threads are woven or knitted into fabrics, which locks in the tension that holds those fibres side by side.
However, these fibres have good “memory”. Whenever they’re exposed to heat, moisture or mechanical action (such as agitation in your washing machine), they tend to relax and return to their original crinkled state.
This fibre memory is why some fabrics wrinkle so easily and why some of them may even shrink after washing.