Ever wondered why your clothes crease after being washed, or why some crease more than others? Andy from Compund Interest has collaborated with Professor Mark Lorch from the University of Hull to make this graphic, which takes a look at the answers to these questions! It accompanies a piece by Mark in The Conversation.
I hate ironing, I’ll do more or less anything to avoid it. So faced with a giant pile of laundry I got easily distracted. I started to wonder why those shirts emerged from the machine looking like a tangled bag of rags. How come the cotton clothes get crumpled so easily? And what’s with easy-iron garments, why don’t they need so much pressing?
Since I’m a scientist I know its important to understand the theory behind a methodology. And so it became imperative, before unleashing the iron and its board, that I found the answers to these pressing questions.
It turns out that the wrinkles in my shirts are all down to the chemisty of plant-based fabrics. Cotton, linen, hemp and so on are predominantly made of cellulose. Cellulose is what’s known as a polymer because it consists of thousands of glucose molecules joined together to form linear chains. Each glucose subunit is “sticky” because it can bind to neighbouring cellulose molecules via something called hydrogen bonds. Individually, these bonds are very weak, but together they form a strong network that gives the fabric its strength.
These hydrogen bonds are particularly dynamic in that they are forever breaking and then rapidly reforming. As a result, clothes start taking on the shape that they are left in. This isn’t a problem if I get around to putting freshly ironed shirts on a hanger. But it is an issue when I chuck them in a heap on the “floordrobe”. As they sit there in a pile, the bonds break and reform, the clothes take up the new shape of the fabric, and the creases set in place.