How Does a Diaper Work?

If you've ever had to change a diaper in your life you've probably wondered how a diaper works.  This past weekend I decided to rip open a diaper and show my daughters (and wife) how, exactly, a diaper works.  When you rip open a diaper (Pampers in my example), you'll see something similar to the pictures below.

As you can see, there is a lot of cotton inside the lining.  The cotton, however, is not the material that does the absorbing of wet stuff.  The cotton acts as padding so that it feels good on a baby's butt.  If the diaper only had cotton in it, it would do a horrible job of preventing leaks.  In addition to the cotton, there are polymers inside the lining.  These are what absorb the liquid.  

In this plastic bag we separated the cotton from the polymers.  The polymers look like tiny little salt particles.  You can see them in the lower right corner of the bag.  Next we dumped the polymers (minus the cotton) into a small bowl.

To see how a diaper works, we slowly added a bit of water to the bowl.  The polymers quickly soaked up the water, growing in size in the process.  

The liquid absorbing polymers clump together very nicely after soaking the water.  Polymers are very good at soaking up liquid, and can soak up liquid that is up to 800 times the weight of the polymer!!!  We decided to test this further by continuing to add water to the bowl until the bowl was full.  

We filled the bowl to the top and the polymers continued soaking up water.  We could have added more water, but the bowl wasn't big enough.  My oldest daughter thought this was very cool.  So did my 2 year old, although she didn't like it when I tore one of her diapers open!

If you have a diaper at home, test this out.  It's very cool!  Just be sure to NOT dump the polymers in the sink.  Since they expand as they get wet, this could create a plumbing nightmare!!!