Tom Pittman's WebLog

2011 December 22 -- ... But Liars Figure

Last time I looked, the USA ranked dead last among industrial nations for math and science education. It shows. Here I am, reading the current issue of FastCompany, which as I noted earlier, is written and published by people whose elevators don't get as high as the people they report on. On page 40 there is this breathless paean praising new detergent bottles made from cardboard. It's filled with innumerate numerical lies, telling how much better these cardboard bottles are for the environment than the plastic bottles they replace.

Don't get me wrong, I'm all for using renewable trees instead of petro-chemical plastics, because the last oil was made thousands (or, if you are of the Darwinist religion, millions) of years ago; when it's gone, it's gone. New trees are still growing, with no end in sight. Besides, much of our oil still comes from the Arabs, and I'd rather not be dependent on them after 9/11.

First the credible facts. The plastic bottles are "at least 80% recycled plastic." The recycling process washes the old plastics, "1 gallon per 37.2 bottles." Making cardboard bottles also requires water, but each gallon makes 76 bottles. Elsewhere they tell us that the cardboard bottles require a plastic liner, which uses 1/3 as much resin as the plastic bottles. Plastic bottles are shipped whole, but the cardboard ones are "halved" (probably made that way) and stacked, so 6 times more fit into a truck.

They don't tell us that shippers charge by the ton, not by volume. There is some extra "tare" weight for shipping crates holding plastic bottles, and the truckers might charge slightly extra to cover the higher percentage the overhead weight of their trucks costs them, but not so much that the actual shipping cost ratio is 6:1. If it were, they could ship the plastic bottles as halves also. It's obvious there's not that big a benefit as to overwhelm the cost and effort to put the halves back together. There's a bigger benefit for the cardboard bottles, because the liner must be inserted, which would be quite difficult through the narrow bottleneck.

They don't tell us how much energy goes into each process, although there are hints that the cardboard process might be more complicated (binding the halves back together and inserting the liner before filling). That's probably significant. Energy is more valuable than water, and it's mostly not renewable. The carbon freaks also care about the carbon load of energy, although that is really a political, rather than environmental issue.

When you count the plastic liners, it looks like each gallon of water makes only 45 bottles, merely a 20% improvement. It takes some algebra to figure that out from the given information, which is probably too much to expect from people who came through the American public education system.

The final paragraph is the worst:

Most plastic goes to the dump, where a cubic meter holds either 520 empty 1-liter plastic jugs or 40,000 pouches. Cardboard fares better: 81% is recycled in the U.S.
If you were reading carefully, you might have noticed in the previous paragraph that all of that recycled cardboard comes from the stores. Consumers don't waste their time recycling stuff. Stores have empty boxes (which the recycler pays them for), but not empty jugs, so boxes get recycled and jugs don't. No consumer is going to separate the plastic liner from the cardboard shell, and then discard the liner only; like bimetalic cans, the recyclers don't want mixed materials, so everything goes to the dump. Replacing the plastic jugs with cardboard jugs will not change the behavior: the jugs will still go to the dump, bringing the new percentage of recycled cardboard down to something much closer to today's percentage of recycled plastic.

Furthermore, plastic is stronger than cardboard, so the empty cardboard jugs are much more bulky (that's why it's only 6 times more compact to halve them, instead of 20x like the plastic might be) and will consume more space in the dump, not less. However, cardboard is biodegradable; microbes eat it and make -- horrors! -- carbon dioxide, which trees eat and make new wood, from which new cardboard can be made.

There is another lie hidden here in this last paragraph. The 520 number comes from the number of round objects that can be packed compactly in a cubical space. Detergent bottles are usually designed to be squarish, thereby to get them to fit more compactly. But empty bottles are all crushed flat in the garbage truck less than two blocks from where they are picked up. The number is pure fiction.

As I said, I'm in favor of reducing our dependency on imported petroleum, but not for the given reasons, which are nothing more than marketing PR (aka lies) fabricated to justify charging higher prices. Too bad the editors of FC lack the numerical skills to weed out and discard the noise, so they can report on the significant innovation.

Oh well.


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