There are "spool-knitting machines" that will rapidly make i-cord for you:
These spool knitting kits are often sold as children's knitting toys and are available at most craft stores
See Examples
I-cord is a narrow tube of knitting, that is often used for the
handles of a bag, cords to tie on a hat, to edge a garment, or appliquéd on for
a decorative effect.
Uses for I-Cord
I-cords is great because once you've made one, you'll start thinking of all
sorts of uses for them. Here are just a few ways you might use them:
Strap or handles for a purse or bag.
Straps for a knitted shirt or dress.
Use it as a belt. Make a
headband.
Sew the cord together to make a flower, a spiral, or some other shape
you can use on another knitted project.
Use as a tie for a hoodie or in place of elastic in a hem.
How to Loom Knit an I-cord on a Knifty Knitter
Spool
Knitting
Aka: corking, knitting nancies
Wikipedia Article: Spool Knitting