there are two closure methods that seem to work well.
The "party stores" around here (AKA Mardi Gras supply shops) have balloon closures in a plastic clip form or a small plastic disc.
The disc thingy is fastest as it takes only a couple seconds per balloon to do but requires a fixed hook similar to a small crochet hook firmly fixed to something. Normally that something is the helium bottle. The disc is used to both seal the balloon and attach a string, but the string is not necessary for it to work. If I was doing it I'd check with the party store and find out if they have the"large" regulators with a separate helium botle tail piece that have the attached hook, then swap out the tailpiece for a yoke. Alternately mount an appropriate sized crochet hook in a vise and go for it. Using this method you should be able to do 3-400 ballons an hour if you have someone to help load the discs on the hook and remove the filled ones. Juggling the hose mounted valve and closing leaves you short one hand anyway.
The clip closures are a bit slower unless you have two people to fill. One fills and passes off to the clipper. When the clipper's fingers get cramps the roles exchange. 200 an hour is a good rate for the clips.
I'm normally the guy that got stuck with balloon duty for school and church carnivals. We'd blow up 2-300 ballons in an hour or two for helium ones, plus the air filled ones (using the hook on the helium tank for closure) for the dart throw booths. I even broke down and bought my own helium regs for the job.
I did the "tie it in a knot" closure thing one year. Never again. It took over a week for the fingers to heal up the hangnails and splits from rolling the knots off the fingers.
If recovered both closures types are reuseable, but at less than $.02 each in quantity it's not normally worth it.
BTW The "tilt valve" shown in the earlier post is the same one used on every helium rig I've seen.
FT
