Aida said the new material is as strong as petroleum-based plastics but breaks down into its original components when exposed to salt.
If this means that it does not break down when exposed to just water, that’s a pretty big deal. Water solubility has been the major issue making biodegradable plastics useless for food packaging (typically you want to either keep the food wet and water in, or dry and water out - either way water permeability is a problem).
Of course most foods also contain salt, so… I guess that’s why the article talks about coatings. If the material has to be coated to keep it from breaking down too fast, what is the point? either the coating will prevent it from breaking down, or it just moves the problem to the coating not breaking down.
Food is a reasonable target for biodegradable packaging because you don’t really expect the food to sit around for more than a year (for long-term food packaging you just wouldn’t use a biodegradable material).
Packaging products that might have a long shelf life is more problematic. If the material breaks down in saltwater then it will start breaking down if someone picks it up with sweaty or recently washed hands.
Or probably in shipping containers. I assume the salty air on cargo ships would be an issue depending how the bulk of the product is stored while in transit
Well right, and coating them with plastic means that they leave plastic residue behind if they break down in an uncontrolled environment, and increases the cost and complexity of recycling:
If the paper has a plastic or aluminum coating, it can be recycled, but it is much more expensive and complicated.
Some plastic coatings can be separated from paper during the recycling process. Still, it is often cheaper and easier to use virgin materials to create new products than recycling paper coated with plastic.
Paper coated with plastic isn’t suitable for composting, and most times, such products are incinerated for heat or landfilled rather than recycled.
Yes they already exist. They are not really better than pure plastic, they’re kind of a form of greenwashing because they appear to be environmentally friendly.
If the material has to be coated to keep it from breaking down too fast, what is the point?
Presumably you could only coat certain faces of the material (like ones touching food). Or maybe the coating could degrade in another more time-known fashion. So if the coating would be expected to last no more then 3 years then after the plastic could start to degrade.
If this means that it does not break down when exposed to just water, that’s a pretty big deal. Water solubility has been the major issue making biodegradable plastics useless for food packaging (typically you want to either keep the food wet and water in, or dry and water out - either way water permeability is a problem).
Of course most foods also contain salt, so… I guess that’s why the article talks about coatings. If the material has to be coated to keep it from breaking down too fast, what is the point? either the coating will prevent it from breaking down, or it just moves the problem to the coating not breaking down.
Food is not the only thing that gets packaged. The worst example that comes to my mind is the way they package microSD cards.
What, you don’t think 1cm² of product should be packaged in a 7×10 cm doubled-up plastic sheet?
Food is a reasonable target for biodegradable packaging because you don’t really expect the food to sit around for more than a year (for long-term food packaging you just wouldn’t use a biodegradable material).
Packaging products that might have a long shelf life is more problematic. If the material breaks down in saltwater then it will start breaking down if someone picks it up with sweaty or recently washed hands.
Or probably in shipping containers. I assume the salty air on cargo ships would be an issue depending how the bulk of the product is stored while in transit
It’s cool we’ll just slap some PFAS on there and fix 'er right up
Plastic coated cardboard containers exist already, and are being widely used for food.
Well right, and coating them with plastic means that they leave plastic residue behind if they break down in an uncontrolled environment, and increases the cost and complexity of recycling:
https://www.almostzerowaste.com/non-recyclable-paper/
Yes they already exist. They are not really better than pure plastic, they’re kind of a form of greenwashing because they appear to be environmentally friendly.
That’s my impression, since all the “environmentally aware” companies use them.
Presumably you could only coat certain faces of the material (like ones touching food). Or maybe the coating could degrade in another more time-known fashion. So if the coating would be expected to last no more then 3 years then after the plastic could start to degrade.