If those cups are made of the material I'm thinking of, all you have to do is take a propane torch to it. The plastic will shrink as it heats up, just don't burn a hole through it 8O Really cool to watch, just wondering how many cups he tried it on before he got it to shrink evenly. Nothing special about that process at all.
If it's the same material plastic I'm thinking about, one day we got something else made of the same or similar plastic too close to a construction heater in the shop, but not close enough to burn it. It actually shrunk when it heated up. Just like heat shrink tubing. Was really cool to watch.
Okay, story time. We did this back at camp with powerade bottles. This kid was saving them and had like a million empties. So we shrank them all over the fire, like 20 of these things, until they were about... I dunno, 8 ounce sized? (Propane will burn through them so fast, we used an evenly spread charcoal fire) and then put them all back in his cooler. He comes back, and is suddenly very pissed off. (Caps still fit because the top is made of thicker plastic.) Was hilarious. Heh. Sorry. Random rambling.
heh yeah.. last summer, my buddies and i would take about 5-7000 match heads and put 'em in a 20 oz and hook a fuse to it. we'd light the fuse and run (or walk - depends on the length of the fuse i guess). when that baby went off it shrank the plastic bottle. it was pretty cool.
but over the winter we cut off over 20000 matchheads and put them all in a 2 liter. that was hella cool. :twisted: that set off a few car alarms. ..but even then, it shrank the bottle a little bit.
too bad, we should've kept the bottles and sold them on ebay. we could've got our money back for what we paid for in matches.
oh well... *shrugs* you live, you learn.
found it on fark.com well, totalfark, the link didnt get greenlit. sent the dude a question, stating the propane, and he said, get this, that he had no idea you could do it that way, that his method involves water and electricity, and not heat. i think hes full of it, but hey.