The provided are a four side seal packaging bag and a preparation device and method thereof. The preparation device includes at least: a film material conveying mechanism, configured to continuously convey a film material of a packaging bag along a length direction of the film material; a folding mechanism, configured to fold the film material conveyed by the film material conveying mechanism; a cutting mechanism, configured to cut the upper film material; punch-and-cut mechanisms, configured to form square punch-and-cut regions and separate the square punch-and-cut regions from the side accordion film materials; a side accordion forming mechanism, configured to perform a forming operation on the side accordion film materials; and a hot-sealing mechanism, configured to hot-seal the upper film material, the formed side accordion film materials, and the lower film material.

In order to successively make plastic bags each of which includes panel portions, side gusset portions and a zipper portion, a web of panel material 9 is folded and folded back along longitudinal folded lines 14, 15 and 16 and longitudinal folded back lines 17 and 18 into superposed two layers having opposite side edges at each of which a folded portion is formed. The web of panel material 9 is slit along the longitudinal folded line 16 into two divided parts after being folded and folded back. The divided parts are separated and spaced from each other. In addition, the folded portions are split at positions into sprit portions and removed at the positions partially, a body of zipper material being disposed between the sprit portions.

A flexible package having a closure device and a lap or fin seal is provided that reduces or eliminates an air gap present at the fin or lap seal portion of conventional packages. The package can include a film with a closure applied to the film. A bridge material is provided to the film to fill the air gap when the closure is in a sealed condition. The flexible package alternatively can include a film having a closure device applied to the film transverse to the first and second side edges of the film, with the first side edge portion extending into the fin seal such that at least a portion of the first side edge portion to eliminate an air gap between the fin seal and at least one of the first and second side edge portions.

A system for applying a fastening material to a substrate is provided. The system may include a first material source including the substrate. The substrate may define a first length extending from a first edge to a second edge and the first material source may feed the substrate in a first direction transverse to the first length. The system may additionally include a second material source including the fastening material. The fastening material may define a second length extending from a third edge to a fourth edge, whereby the second length is substantially equal to the first length and the second material source feeds the fastening material in a second direction transverse to the second length. The system may also include an applicator system that secures the fastening material to the substrate.

The provided are a four side seal packaging bag and a preparation device and method thereof. The preparation device includes at least: a film material conveying mechanism, configured to continuously convey a film material of a packaging bag along a length direction of the film material; a folding mechanism, configured to fold the film material conveyed by the film material conveying mechanism; a cutting mechanism, configured to cut the upper film material; punch-and-cut mechanisms, configured to form square punch-and-cut regions and separate the square punch-and-cut regions from the side accordion film materials; a side accordion forming mechanism, configured to perform a forming operation on the side accordion film materials; and a hot-sealing mechanism, configured to hot-seal the upper film material, the formed side accordion film materials, and the lower film material.