Abstract: An apparatus for detecting the heat-sealed interfaces of plastic film being fed into a machine includes a plurality of light sources opposed to a heat-sealed plastic film. The lights are spaced from each other in directions parallel and perpendicular to the direction in which the plastic film is fed. An optical sensor is opposed to the plastic film, and a cover plate is placed between the optical sensor and the plastic film, the cover plate including small hole or narrow slit through which light passes. The lights reflect from or permeate through the plastic film and then pass to the optical sensor. The optical sensor image-recognizes the reflected or permeated lights and reads the minutely rugged surface of the heat sealed portion to detect the heat sealed interface of the plastic film.

Abstract: The invention relates to a plastic film heat seal apparatus which comprises a heat seal bar covered with at least one low adhesive sheet. The heat seal bar is pressed against superposed layers of plastic film so that the layers of plastic film can be heat sealed with each other by the heat seal bar to have a heat sealed portion whenever the layers of plastic film are intermittently fed in a direction and temporarily stopped. The low adhesive sheet is interposed between the heat seal bar and the layers of plastic film for protection of the layers of plastic film when the heat seal bar is pressed against the layers of plastic film. The heat seal bar is then retreated and spaced from the layers of plastic film to permit the layers of plastic film to be fed again after being heat sealed. The heat sealed portion includes upstream and downstream edges in the plastic film feeding direction.

Abstract: An apparatus is arranged to successively make plastic bags. The apparatus comprises a trapezoidal plate including a short edge having opposite ends from which opposite oblique edges extend divergently. The trapezoidal plate comprises a double walled structure in which clearance means is formed between walls. The apparatus further comprises drive means by which the trapezoidal plate is moved in a direction of height of trapezoid so that the short edge can be engaged with the bottom gusset material. In addition, the apparatus comprises a pair of folding plates arranged to be engaged with the bottom gusset material and then inserted into the clearance means at positions corresponding to the oblique edges in accordance with the movement of the trapezoidal plate so that the bottom gusset material can be inserted into the clearance means by the folding plates to be folded into halves along the short edge and folded into the clearance means along the oblique edges.

Abstract: An apparatus is arranged to successively make plastic bags each of which includes two layers of panel portion superposed to define aligned top edges, first and second side edges and bottom edges. The plastic bag further includes a first side gusset portion disposed between and extending along the first side edges, a second side gusset portion disposed between and extending along the second side edges, and a bottom gusset portion disposed between and extending along the bottom edges. The apparatus comprises feeding means for feeding a main material intermittently for a length along a feeding path. The main material comprises the layers of panel portion and the first and second side gusset portions continuing longitudinally thereof respectively, the feeding means feeding the main material longitudinally of the layers of panel portion and the first and second side gusset portions.

Abstract: In an apparatus for making plastic bags from a web material comprising two or more layers of plastic film, the material is intermittently fed for a length along a longitudinal feeding path, to successively make plastic bags with wastes, each of the wastes having upstream and downstream edges. The apparatus includes partially cutting means disposed at a first station predetermined along the feeding path. The material is partially cut by the partially cutting means along the upstream and downstream edges of waste whenever intermittently fed and temporarily stopped. The apparatus further includes waste removing means disposed at a second station predetermined downstream of and at a distance from the first station. The waste reaches the second station when the material is intermittently fed again after partially cut by the partially cutting means. In addition, the apparatus includes discharge means disposed at a third station predetermined downstream of and at a distance from the second station.

Abstract: An apparatus is arranged to successively make plastic bags each of which includes two layers of panel portion superposed to define aligned top edges, first and second side edges and bottom edges. The plastic bag further includes a first side gusset portion disposed between and extending along the first side edges, a second side gusset portion disposed between and extending along the second side edges, and a bottom gusset portion disposed between and extending along the bottom edges. The apparatus comprises feeding means for feeding a main material intermittently for a length along a feeding path. The main material comprises the layers of panel portion and the first and second side gusset portions continuing longitudinally thereof respectively, the feeding means feeding the main material longitudinally of the layers of panel portion and the first and second side gusset portions.

Abstract: In an apparatus for making plastic bags from a web material comprising two or more layers of plastic film, the material is intermittently fed for a length along a longitudinal feeding path, to successively make plastic bags with wastes, each of the wastes having upstream and downstream edges. The apparatus includes partially cutting means disposed at a first station predetermined along the feeding path. The material is partially cut by the partially cutting means along the upstream and downstream edges of waste whenever intermittently fed and temporarily stopped. The apparatus further includes waste removing means disposed at a second station predetermined downstream of and at a distance from the first station. The waste reaches the second station when the material is intermittently fed again after partially cut by the partially cutting means. In addition, the apparatus includes discharge means disposed at a third station predetermined downstream of and at a,distance from the second station.

Abstract: An apparatus is arranged to successively make plastic bags each of which includes two layers of panel portion superposed to define aligned top edges, first and second side edges and bottom edges. The plastic bag further includes a first side gusset portion disposed between and extending along the first side edges, a second side gusset portion disposed between and extending along the second side edges, and a bottom gusset portion disposed between and extending along the bottom edges. The apparatus comprises feeding means for feeding a main material intermittently for a length along a feeding path. The main material comprises the layers of panel portion and the first and second side gusset portions continuing longitudinally thereof respectively, the feeding means feeding the main material longitudinally of the layers of panel portion and the first and second side gusset portions.

Abstract: In an apparatus for making plastic bags from a web material comprising two or more layers of plastic film, the material is intermittently fed for a length along a longitudinal feeding path, to successively make plastic bags with wastes, each of the wastes having upstream and downstream edges. The apparatus includes partially cutting means disposed at a first station predetermined along the feeding path. The material is partially cut by the partially cutting means along the upstream and downstream edges of waste whenever intermittently fed and temporarily stopped. The apparatus further includes waste removing means disposed at a second station predetermined downstream of and at a distance from the first station. The waste reaches the second station when the material is intermittently fed again after partially cut by the partially cutting means. In addition, the apparatus includes discharge means disposed at a third station predetermined downstream of and at a distance from the second station.