The definition of a two-way zipper is one where you can close or open the zipper from two opposite ends at the same time.
There has always been confusion regarding the “two-way” function of a zipper. Is two-way separating generally used for an outerwear jacket application? Or maybe a two-way, closed, head-to-head zipper for a gym bag, a tent or backpack application? You might need a two-way closed bottom-to-bottom zipper for a coverall.
Two-way, closed, head-to-head zippers are those where the sliders meet together to close the zipper. This zipper does not separate.
Two-way, closed, bottom-to-bottom zippers are those where the sliders meet away from each other to close the zipper. This zipper also does not separate.
Two-way, separating zippers are those used in applications where you can open the zipper from the top or bottom and the application comes completely apart, like a jacket front. This is a separating zipper.
Learn more about various zipper types in the YKK Digital Showroom.