Unfortunately I can't get completely miffed about it because I love a couple of flavors of capri sun. Plus it's handy as heck to pop them in the freezer then pop them in my lunch box cooler. They serve a dual purpose here. They keep things cool in the lunchbox cooler, and by the time lunch is around they have thawed out.
The other thing I love about these things is all the cool things I've seen people make with them. Wallets, purses, bags, you name it. Just do a google search for "capri sun projects" or "DIY capri sun". You'll see what I mean
I have a bit higher aspirations than that. I want to try making an umbrella or a tent out of them. But the tent might be a bit ambitious. Most people sew them together with thread, fishing line, or upholstery thread. Or they will tape them together with Duct Tape or Gorilla Tape. I wanted to weld them together.
At first I looked into how they do it industrially. Apparently they either use microwaves or ultrasonic welding. Do-able, but not for everyone. Certainly not with parts I had laying around the house, and certainly not cheap.
In the end I found a soldering iron or wood burner works like a charm.
Step 1: The science...
What is CAPRI SUN packaging made from? Is it recyclable?
CAPRI SUN pouches are polyester-reverse side printed to aluminum then laminated to polyethylene (a plastic polymer). Unfortunately, this packaging is not recyclable.
So it looks like a laminate of aluminum foil and polyethylene. Ok fine. What is the melting temperature of polyethylene? A quick trip over to Wikipedia and I had my answer. I love Wikipedia, best invention ever. The nobel prize should go to the guys that invented it. They are certainly more deserving than a couple of the past winners.
For common commercial grades of medium- and high-density polyethylene the melting point is typically in the range 120 to 130 °C (250 to 265 °F). The melting point for average, commercial, low-density polyethylene is typically 105 to 115 °C (220 to 240 °F).
Ok so the melting point is somwhere between 220°F (115°C) and 265°F (130°C). Ok, that shouldn't be a big problem. I think clothes irons only get up to about 200°F so I'm thinking an Iron wouldn't work.