Thursday, February 23, 2012

An Edible Drink Bottle - No Thanks, I've Lost My Appetite

Plenty of people take issue with the existence of single-use water bottles and the related disposal issues, so the recent announcement of an "edible drink bottle" being developed by a Harvard professor may seem like a real winner. There is nothing to dispose of - you can just eat the bottle when you are done. No waste, no garbage, no nothing to end up in the environment.

But before we all go out and invest in this technology, we need to review everything that a drink bottle does:.
  • It needs to seal the water in and all other contaminants out.
  • It needs to be made from materials that will not leach unsafe levels of chemicals into the water, or react with the water.
  • It needs to not have any structural failure:
    • during shipment from the bottles' manufacturer (who is often someone different than the company filling the bottle) to the filling plant
    • while it is in the filling equipment
    • while the bottle is put into
      • the secondary packaging (often shrinkwrap)
      • into the tertiary packaging (a cardboard box)
      • additional packaging (such as to secure it to a pallet)
    • or during shipment via (multiple) trucks or boats
    • while on the shelf or rack, particularly when multiple layers of filled bottles are stacked on top of it
    • during the "normal" lifespan that the consumer has it
    • Keep in mind that during shipment and in the hands of the consumer, the bottle can see temperature extremes from below freezing temperatures to 140 oF or more, as well as UV light which can degrade polymers. If there is structural failure, the water will leak from the bottle, requiring that at the very least, that bottle be thrown away or recycled. Keep in mind that that bottle's contents are then also wasted. Depending on the extent and location of the leaker, the cardboard packaging may be weakened so that handling the other bottles or even the pallet with a forklift may be a problem, and therefore many more bottles may end up being trashed.
  • The bottle needs to cost as little as possible.

  • The water can only diffuse very slowly through the bottle's walls. Once too much water has evaporated, the bottle no longer holds the volume stated on the label, say 500 ml. Now it's mislabeled, and cannot be sold, so into the wastestream it goes.
I think this list is a pretty daunting challenge for the new material. Nothing was mentioned about the strength of the new material nor the diffusivity of water and other liquids through it, but considering that it is described as a "membrane", it probably leaks like a sieve. I've done enough product development to know better than to expect detailed costs estimates at this point, but this new material will be expensive if for no other reason than it will have to be treated as a food item and that means a whole boatload of regulations need to be followed in the production of it that a simple PET bottle is exempt from. But the real limitation will be this: if the bottle is to be edible, then it will have to be kept clean and sanitary, just like all food is, and the only way to do that is to have additional packaging around the bottle and that pretty much defeats the whole purpose of the bottle, doesn't it? Unless a PET bottle is filthy, people give little regard to where it's been or who/what has touched it, but if you are going to be eating that bottle, then everything contacting it will be a concern. A coworker handing you a bottle would be just like that coworker handing you a donut - not the box of donuts, but a donut directly with their hands. Anybody still hungry for these bottles?






7 comments:

Anonymous said...

I see the only real competitor to plastic in bottles is paper lined with a sealant, much like milk in paper cartons. Boxed water is better.

John said...

The "sealants" (more properly called "barriers") can present problems with recycling the paper.

Eric F. Brown said...

Let's not forget that items humans consume can also be consumed by a variety of vermin, e.g., rats, locusts, and nasty microbiological organisms. Modern packaging protects us from many of these pathogens because they're inedible.
This sounds like a brainstorming idea that should have been cut from the list of things to do.

John said...

Eric,

I never even thought of that angle. Great of you to mention it.

Nicholas said...

They claim to have "significant water diffusional resistance", but I'd be interested to see how they quantified it. Still looking for more information, they don't seem to have published anything on it yet.

Anonymous said...

I'll preface this by saying I'm no chemist, just a bored 3rd shift cubicle jockey. But would sanitation be less of a concern if the bottle had to be "cooked" in order to be eaten? I'm envisioning a plastic bottle made from some sort of corn based plastic that when microwaved would "puff up" into something with a texture/flavor similar to a bugle corn chip.

John said...

Anonymous,

Clever idea, although cooking only "sanitizes" certain types of contamination (bacteria), and would do nothing for dirt (hair, soil particles...). A clever idea nonetheless.