I noticed that the actual bag that carries the milk is not recyclable in my community and I can see why. It is however an extremely useful little tool that you pay for, discard, and readily pay for a substandard substitute on a daily basis.
Manufacturers go to great lengths to provide high quality, "industrial strength" packaging to ensure their product arrives to you, the end consumer, safely. You wouldn't have it any other way and you pay for it. The problem arises when you throw this away and replace it with an expensive "consumer grade" product. The milk bag is an excellent example of this. There are many more, I'm sure.
The lowly, food grade, extremely tear resistant, stretchable, cuttable, waterproof, thick walled and well bonded milk bag. We throw this away, alot, and buy cheap sandwich and freezer bags that leak or easily burst at the seams for outrageous prices considering my opinion of product failure. The milk bag has uses beyond just a bag due to its unbelievable strength. Trust me, try to stretch it with any sort of control and you'll see what I mean. Like I said..."Industrial Strength" not wimpy little whiney, "I wish I could live up to your expectations" consumer strength.
What you need: 1 milk bag
Step 1: Wash, Rinse, Dry
To dry properly, the bag must be expanded to keep the sides apart and stood vertically or hung. I finally found aother use for that wire banana stand.
Note - Cutting the top of the bag open at this point will make washing and drying easier, but it will limit the uses later.
Step 2: Open End Uses
Use as a grow bag for hanging or potted plants by perforating it to allow for drainage.
Step 3: "Unopen" end bag uses
The bag can then be easily filled with air using a straw or equivalent and with liquid using a funnel.
To create the "fill tube", simply and gently stretch the corner from the bag. This will take a short while and will require patience and a little strength. Allow the heat from your hand to soften the plastic and gently pull it allowing it to slip through your fingers to prevent overstretch. Repeat many, many, many times and do not pull too hard or too soft. You'll get it with a little practice and may even develop a better way. This stuff is stronger than you think. PULLLLLL or you will be here all day. If it tears, you will have a replacement soon enough.
Try to keep the stretch as even as possible for strength and extend the tube as far as required to easily tie it off.
Step 4: The uses are limited by your needs.
Fill it with gas and you've got an inflatable travel pillow (Try buying a more comfortable or durable one), lumbar support (nice and bouncy), bath pillow, noise maker, 1/30 of a mattress, 1/1000 of a lot of fun if coupled with a pit to fill, a really ugly balloon, a not so ugly balloon with some work and creativity. Duct tape it to your dash board and you've got air bags. I want to fill one with expanding foam inside of a form to make a brick that can be used for building, insulation, a floatation device, or just to throw at someone. Fill with sand to make 1L sand bags.
I didn't even mention it as a source of thick sheet plastic for a multitude of uses.
They are strong, thick, very useful and being needlessly wasted when you think of what the alternatives that we pay for are. You can't stop them all because you do go through a lot and they are not endlessly reusable, but you can reduce a significant amount of unnecessary bags being purchased in the first place if you use your imagination.