Coil
zippers now form the bulk of sales of zippers world-wide. The slider runs on
two coils on each side; the "teeth" are the coils. Coil zippers are made of nylon coil and are thus also known as nylon zippers.
Molded
zippers are identical to metallic zippers, except that the teeth are plastic
instead of metal. Metal zippers can be painted to match the surrounding fabric;
plastic zippers can be made in any color of plastic.
Metal
zippers are made in brass, aluminum and nickel, according to the metal used for
teeth making. All these zippers are basically made from flat wire. The teeth
are not a coil, but are individual pieces of metal molded into shape and set on
the zipper tape at regular intervals.
