Press to close zippers ( PTC ) have been the standard zippers for 3 side seal pouches for many years and today they have been refined to give improved functionality across a wide range of applications. Now with two or three rows of interlocking flanges, PTC zippers are likely to remain the the default zipper choice for flat 3 side seal pouches.
Velcro brand Press-Loc Zipper is a market leader in Velcro closures. The main characteristic of this style of zipper is it's ease of alignment and minimal pressure required to reclose the pack. For the consumer there is a reassuring audible click when the zipper is closed.
Pocket zippers are a very efficient and user-friendly form of zipper. The pocket zipper opens on the side of the pouch as opposed to most zippers which open on the top of the pack. This makes filling the pouch much easier as the opening of the pouch is not obstructed by the zipper leading to higher machine run times. They are also very user friendly being completely tamper evident and much easier to open and reclose than other types of zippers. This style of zipper is highly recommended for flat bottom and side gusseted pouches.