Shopping Bag Plastic

...."Traditional plastic bags are usually made from polyethylene, which consists of long chains of ethylene monomers. Ethylene is derived from natural gas and petroleum."...

https://en.wikipedia.org/wiki/Plastic_shopping_bag

Ive dealt a lot with thin PE plastic, and it is not as tough as this crazy stuff is. I mean I have carried like 20 ot 30 pounds oc sharp edged canned goods in one bag with no issues ya know? some seem softer than others and some sound crispy when flexed. but all are incredible tough

There are different types of polyethylene....

...."The polyethylene used in most plastic shopping bags is either low-density (resin identification code 4) or, more often, high-density (resin identification code 2).^[14] "...

https://en.wikipedia.org/wiki/High-density_polyethylene

A friend of mine once worked in a plastic bag factory. The strongest version was called "GREX" (spelling uncertain). I think it was a form of PE, but I don't know.

The X may stand for cross-linked, similar to PEX = cross-linked PE.

I think that's what Hula Hoops were made of.....grex

Could be. I would have guessed PP (polypropylene), but I'm not a plastics guy. And then what about Frisbees? Wiffle balls? Ping-pong balls? We need our plastics guy to chime in.

In the plastic bag context,"crinkly" would be a good description of GREX. If you manipulate it, it sorta rattles.

A “fuel”.

If you have a thermal camera, you can play around with plastic bags. Even bags that are opaque (to light) are transparent to long-wave infrared. The infrared has a wavelength of about 10 microns whereas light has a wavelength of 0.4 - 0.7 microns. The thickness of the bag is less that the wavelength of IR and so is basically invisible.

https://physics.stackexchange.com/questions/3750/why-is-a-plastic-bag-transparent-in-infrared-light

Thanx! I'll try that tomorrow with my FLIR-one.

Plastic bags, having been banned in a number of communities, are now considered to be better than reusable bags in these days of coronageddon.

https://www.washingtonexaminer.com/opinion/plastic-bag-bans-arent-helping-us-fight-against-coronavirus

No idea, but various forms of sea-life unfortunately seem to find them tasty. Might be a good idea if supermarkets promoted those old style 'string' type carrier bags. I couldn't find any good data on how many times plastic bags get re-used and where they end up.