How do you turn a few plastic bottles into polyester and performance apparel?

By Kelsey Abbott

The world's got problems. We've got too much of some things - there's too much marine debris in the oceans, the Dutch have too much chicken poop, and there's too much plastic bottle waste just about everywhere.  But we don't have enough of other things, like energy...and, umm, running shirts. Thankfully, there are plenty of resourceful scientists who have figured out how to make energy from poop and marine debris and how to make performance apparel from plastic bottles.

We can turn waste into energy by burning it. That's simple. Turning plastic bottles into performance running shirts seems a little trickier - performance  tops are made out of soft polyester fabric and plastic bottles are made out of, well, plastic. Actually, plastic bottles and polyester shirts are both made of polyethylene terephthalate (PET). So, turning plastic bottles into running shirts is almost as easy as burning chicken turds and fishing gear to make energy.

It all starts when you toss a PET bottle (labeled #1) into a recycling bin. These bottles are sorted at a recycling facility and bundled together in large bales.  The bales of PET bottles are then taken to a PET reclaiming facility. The bottles are thoroughly cleaned, the labels and caps are removed, and the bottles are separated by color (the clear bottles will produce a white-ish polyester yarn and the green bottles produce a green-ish yarn).

Once they're sorted, the bottles go into a grinder where they are ground into small flakes. The flakes are tossed in hot air to give them a hard candy coating and then dried to remove any remaining moisture. Next, the dry, crispy flakes are shoved through hot pipes to melt them into a thick liquid. That liquid gets filtered through a dye plate with 68 tiny holes. As the liquid polyester flows through the holes, it forms filaments that are more than five times finer than human hair. The filaments pool and harden and are then sent over rollers where air entangles the filaments to create a dental floss-like yarn. The machine spools the yarn and then pulls it over hot metal rollers to stretch it and realign the polyester molecules. The resulting yarn is ready to be woven into polyester clothing.

The only difference between the production of recycled polyester yarn and virgin polyester yarn is in the initial material. The production of virgin PET begins with the production of nurdles--teeny tiny plastic resin pellets-made from petroleum and other products. Unfortunately, nurdles are little troublemakers that often find their way into waterways. Additionally, making nurdles requires a lot of energy, much more then grinding up plastic bottles. By some estimates, the production of recycled PET uses 2/3 less energy and almost 90% less water than the production of virgin PET. And of course, no new petroleum is required to produce recycled PET.