Today I went to Staples to get some rubber bands. I use the # 64 bands all the time around the house, particularly in the kitchen, and for some reason they ultimately all disappear and I have to replace them once a year or so. I usually buy a small bag that has maybe 200 bands in it, and it seems to last about a year or two before they all vanish. The little bag is $2, but I noticed today that also have a gigantic bag for $5 which is about 8 times bigger than the small bag. I was very tempted to buy it, but I decided against it because I’ve seen really old rubber bands become stiff and brittle. But under what conditions does this occur? Would they become brittle over time if they were stored in a sealed bag in the dark, or would they last indefinitely under those conditions? Are the ones that I’ve seen that have become brittle ones that have been heavily used and exposed to light? What degrades them?
The cheap rubber used in rubber bands degrades quickly when exposed to light and oxygen but will still degrade (more slowly) in the bag. After several years in or out of the bag most rubber bands are significantly degraded.
Washoe, I see you’re in southern California, which may be part of the answer. Ozone can attack rubber, and parts of SoCal have lots of it. My folks lived in Rancho Cucamonga for many years, and the ozone there was so bad you could smell it. That being said, I don’t remember Simi Valley (I used to live in TO) as being especially ozone-y, but it was a long time ago.
ISTR Feynman commenting on this in one of his books – he worked at CalTech in Pasadena for many years, and he noticed that rubber bands in LA didn’t last as long as they did back home in New York.
I use rubber bands every day delivering mail. We generally tend to wear them out through overuse, rather than have them degrade. I have noticed however, that in the summer heat (100 - 115 in my neighborhood) they will only make a couple days before they get crunchy.
Small bag - $2 - 1-2 years
Large bag - $5 - 8+ years (maybe)
Small bags for 8+ years - $16
So you save maybe $11 over 8+ years? Buy the small bags.
But if you must buy the large bag, keep it in the refrigerator. I’ve kept latex gloves in the refrigerator, and that keeps the unused ones usable for a longer time.
About 20cm.
IIRC they could be ruined in a matter of days if you leave them in direct sunlight. The UV rays devulcanize it. Basically rubber is processed by taking raw rubber, the brittle stuff you get when rubber bands fail, and heating it with sulphur. The sulphur holds the rubber together (perhaps someone else with more of a chemistry background can explain this in more detail). This process is vulcanisation (cheap Star Trek joke). As I mentioned UV rays will reverse it.
Your best bet for keeping your rubber bands good for as long as possible is to put them in the fridge. This’ll slow the process of devulcanization (UV light is just a catalyst, it’ll happen on its own).