There are two methods for manufacturing resealable zipper bags. The first involves direct blown film extrusion; typically, there is a 1.8 cm margin above the zipper, the area near the zipper is thicker, and the bag is formed by heat-sealing and cutting the sides. The second method involves attaching a zipper strip to the film after it has been formed; this approach is primarily used for producing composite bags.
The production of self-adhesive resealable bags mainly involves cross-cutting a single sheet of film and heat-sealing the sides. The front and back panels of the bag differ in length, with one side extending 3–5 cm beyond the other to form a foldable flap. This flap features an adhesive strip-such as a standard self-adhesive or a tamper-evident (destructive) adhesive-protected by a plastic liner; to seal the bag, the user simply peels off the liner and folds the flap over.
Common specifications and dimensions for zipper bags are listed below. The standard thickness is 0.03 mm per side (often referred to as "3-gauge" or "3s"), though thicknesses ranging from 0.03 mm to 0.2 mm are available and can be customized to meet specific requirements.