A plastic bag has a safety even when a flap is not adhered on an outer surface of a side gusset. One of the opposite end portions of the side gusset is obliquely folded in half along a fold line and interposed between the two layers of the side gusset, so that the flap is formed by the end portion between the two layers of the side gusset. The flap includes a folded edge formed by a folded inner edge of the side gusset, and an open edge formed by one of the opposite end edges of the side gusset. The flap further includes a joining edge extending straight or curved and joining the folded edge and the open edge on opposite sides of the fold line.

The present invention relates to a method for making airtight packages (100) made of flexible material that are configured to seal an environment inside the package with respect to an external environment, said packages (100) comprising a front panel (1), a back panel (2) and two side gussets (3, 4) provided at opposite ends of the front panel (1) and of the back panel (2) so as to connect the front panel (1) to the back panel (2). The method comprises a first step of folding a sheet (60) made of flexible material along two first fold lines (L1) which are mutually parallel so as to form a tubular element (61). Moreover, the method comprises a second step that consists in folding an end portion of the tubular element (61) along two second fold lines (L2) that are oblique with respect to the direction of the first fold lines (L1) so as to form an end portion of the tubular element (61) that has two triangular portions (6, 7) having two mutually parallel sides (8, 9) and having a distance between each other equal to twice a first predetermined distance (D1). In addition, the present invention also comprises a machine (200) which allows using such method and a package that can be made by means of such method and such machine.

A square-bottomed packaging bag (1) of the present invention is a square-bottomed packaging bag formed by bending a one-piece soft packaging material and includes a quadrangular bottom surface (10), a front surface (20) and a rear surface (30) standing from two opposite sides of the bottom surface, and a left side surface (40) and a right side surface (50) connecting the front surface and the rear surface, in which each of the left side surface and the right side surface includes a first region (41, 51) positioned on the front surface side, a second region (42, 52) positioned on the rear surface side, and a side-surface-joining portion (43, 53) joining the first region and the second region.

A pinch bottom sack fillable with bulk good includes a sleeve with at least one area element, wherein the sleeve includes a mesh and the area element a handle means including a load element at which a load force is applicable for lifting the sack, and the load element is configured such that it extends at least in some areas at least in a load condition in which the load force acts at the load element opposite to an outer side of the area element.

A first sheet panel is folded along a first fold line, and thereby a first folded part is formed in the first sheet panel. Subsequently, the first folded part is folded back along a second fold line, and thereby a folded-back part is formed in the first sheet panel. A corner cut device cuts a second sheet panel and the folded-back part to form corner cut parts. At this time, the corner cut device prevents the first folded part and a base part of the first sheet panel from being cut.

A female belt-shaped base is attached to a bag body at a region from a female hook to a first end near an open end of the bag body and to a second end near a housing space. A male belt-shaped base is attached to the bag body only in a bonding region without being attached at a region from a position where an engagement portion is continuously attached to a first end near the open end of the bag body.

A storage bag comprising a floor, the floor having four corners and edges, the four corners defining a planar surface; a pair of opposing triangular interstitial regions, each triangular interstitial region having a vertex, two sides, and a base, the base of the triangle co-linear with one edge of the floor; a gusset, the gusset bisecting the floor region and both opposing interstitial regions, the gusset co-linear with the vertex of both of triangular interstitial regions; a pair of opposing body regions, the lower edge of each opposing body regions co-linear with two corners of the floor region; and, an opening, the corners of the opening forming an imaginary plane, wherein the planar surface formed by the corners of the floor region and the imaginary plane formed by the opening of the body region are in parallel planes after the storage bag is opened for use.

A web of first or second material is provided with the spout, and a plastic bag is made from side gusset materials in addition to webs of the first and second materials. An aperture is formed in the web of the first or second panel material, and the spout is inserted into and positioned with the aperture, whenever the webs of the first and second panel materials are fed intermittently. After the webs of the first and second panel materials are superposed on each other, whenever the webs of the first and second panel materials are fed intermittently, the webs of the first and second panel materials are heat sealed with each other in a longitudinal direction thereof by a longitudinal seal device, and the webs of the first and second panel materials are heat sealed with the side gusset materials in a width direction thereof by a cross seal device.

A bottom-gusseted package comprising a package body, and a bottom gusset positioned transversely of a longitudinal axis of the package body. Formation of the bottom-gusseted package is effected by positioning individual sleeves transversely of the longitudinal axis of a flexible web which forms the package body. During package formation, the flexible web is folded and cut to form individual packages, with each individual sleeve positioned to form a bottom gusset in a respective package. Attendant to folding of the flexible web, each gusset-forming sleeve is folded. Optionally, the individual sleeve portions can be configured such that when the flexible web is cut to form individual packages, each individual sleeve is cut to form a bottom gusset in one package, and a top sleeve portion in an adjacent package.

An apparatus is configured to make containers from sheet material. The apparatus includes a supply station for supplying a film having at least one folded portion having three or more film flaps folded and superimposed with respect to each other; a welding station configured to receive the film. The welding station comprises a welding head configured for welding the folded portion of the film and forming a container defining a housing compartment; the welding head comprises a heater made of electrically conductive material whose electrical resistivity, at least in a predetermined temperature range, decreases upon the increase of the temperature of the same electrically conductive material.