Why does clothing need to be washed?
We put a freshly ironed garment on in the morning and by evening it needs to be washed. What do the clothes pick up during the day?
There are several things.
First and foremost there are your natural body chemicals. These are the fatty acids in your skin (this is collar grime). Then there are a class of compounds called volatile fatty acids (VFAs). These are the smelly things that cause body odour.
Then, of course, there may be any number of other things – food stains, oil or grease, and so on.
As the clothing gets older, particularly cotton, the fibres tend to break, with little bits of fibre sticking up in the air. This is called pilling (believe it or not this is so little known that you don’t get any hits with Google). This is what gives older clothes their faded, yellowed look – the little bits of the cotton strands scatter the light giving a yellowish look.
So that is essentially it – mostly your clothes contain body chemicals. This is the major task of any laundry detergent – but as we shall see, there is a little bit more to it than just removing them.
Tomorrow we will start looking at laundry detergents, with particular emphasis on the many components that they potentially contain, and what separates the men from the boys.
Later on we’ll also look at prewashes and pretreatment options