Friday, March 6, 2009

Caps Off to Recycling

Since I’ve become the new garbage/recycling guru in my group of friends it seems like people keep asking me questions about their trash. I can usually fend them off with a dismissive answer or a smart-ass comment, especially if I am married to them, but this week my wife asked me why plastic bottle caps are not recyclable. I didn’t have an immediate response, but my gut reaction was to say, “What the Hell are you doing out of the kitchen?!? Git back in there, and take those shoes off!” Once she bowed down to my obvious dominance I explained that I thought that they probably were recyclable, but there was probably a separation issue. After I thought about it for a little while I figured that there were too many “probably’s” in that response so I looked into it.

Initially, I thought that there must not be enough material of value to worry about since they are so small relative to the bottles themselves. However, around two million plastic beverage bottles are used every five minutes in the U.S. alone. That means that there are over 210 billion bottles consumed in the U.S. annually. If you were to stack the caps from all of those bottles on top of each other they would reach to the moon and back three times (~1.7 million miles). If they were spread out evenly, just touching each other, they would cover somewhere in the vicinity of 53 square miles. That pretty much chucks the quantity argument right out the friggin’ window there.

One of the major barriers to recycling the caps is obviously separating the cap material from the bottle material. Caps are generally made out of polypropylene (PP #5), which is recyclable. Recycled polypro is usually made into plastic items that have some strength such as rakes, buckets, barrels, etc. The bottles themselves are almost all made out of polyethylene terephthalate (PET #1). This material is generally made into post consumer products like fleece, polyester, carpet, prison shanks, etc. One huge problem with recycling is the separation and sorting of materials, and any labor lost on this task pretty much negates any monetary value of the material right off the bat. Currently, many plastic bottle sorting machines cut off the top of the bottles in order to ensure that there is no cross contamination of the PET material from the bottles with the PP of the caps. The cut-off portion of the bottles is then just landfilled. Contamination of one type of plastic resin with another will either destroy or seriously degrade the physical properties of the bulk material. One reason for this is that there is about a 100-degree temperature difference in the melting points of the cap material and the bottle material. As an example, one stray PVC bottle can ruin a melt of 10000 PET bottles. Some retailers will accept large bags of sorted caps for recycling, but it is pretty much just a marketing maneuver to get you into their stores since a couple of bags of worthless caps aren’t going to put a dent in the 210 billion that would otherwise end up in the landfill every year.


Additional complications with caps are that bottles dry out faster with the caps off. Food contaminants are another big problem with recyclable materials. Also, the bottles are easier to crush without the caps. In fact capped bottles can explode and injure the poor saps that bale this useless crap for shipment overseas...As if their jobs didn’t suck enough. Also, the small caps tend to jam up the equipment that is used to sort and process the larger bottles.

So, I guess the short answer to the original question would have been, “Caps are recyclable, but they are too much of a pain in the arse to dick around with.” As always, I have to take the long way around to get back to where I started. Thanks for the inadvertent blog suggestion, Steph, and if anyone has anything else that would like to hear about, please let me know.

3 comments:

Rachel said...

I just found your blog! Yay! We have run into the cap recycling issue as well, but luckily for us there is a specific bin at the local recycling plant that takes rigid plastics, including #5 caps. Just tell Steph you guys should re-locate to P-town ;).

TJ said...

Well, that settles the old quandary about why Stephanie is out of the kitchen, but what about the CAPS, man?

Good blog, it's much clearer, now. Thanks Dan!

Hippy said...

Why don't they make them out of something cleanable and re-useable for fuck sake?