Abstract: A method and apparatus for forming a bag provides a tube of material that is passed over a former. A portion of the tube is folded over the former to define the rim of the bag. Portions of the rim are then welded. The apparatus includes arms that move transverse to the tube. The arms carry crimping fingers that pivot to fold the tube up and in over the former.

Abstract: A former allows rectangular tubes of material to be quickly formed for creating bags having rectangular cross sections. The former provides a transition between a round former and a rectangular former so that the material used to form the bag is initially wrapped into a tube around a round former so that the material does not tear on the corners of the former. The round tube of material is then drawn down over the former of the invention to change the round tube to a rectangular tube that may be formed into the bag.

Abstract: A method and apparatus for forming a bag provides a tube of material that is passed over a former. A portion of the tube is folded over the former to define the rim of the bag. Portions of the rim are then welded. The apparatus includes arms that move transverse to the tube. The arms carry crimping fingers that pivot to fold the tube up and in over the former.

Abstract: A method and apparatus for forming a bag provides a tube of material that is passed over a former. A portion of the tube is folded over the former to define the rim of the bag. Portions of the rim are then welded. The apparatus includes arms that move transverse to the tube. The arms carry crimping fingers that pivot to fold the tube up and in over the former.

Abstract: A stand up bag has an indented, cup-shaped bottom wall that allows the bag to stand up. A lower rim is formed between the bottom wall and the sidewall. Portions of the rim are welded so that the bottom wall is held in its indented position. The invention provides numerous different weld patterns for the lower rim.

Abstract: A method for manufacturing a stand up bag having an indented bottom wall includes the steps of forming a tube of material and sealing the end of the tube. The sealed end is then moved up with respect to the sidewall to form a downwardly-extending rim. Portions of the rim are then welded to hold the bottom wall in this position.

Abstract: A former allows rectangular tubes of material to be quickly formed for creating bags having rectangular cross sections. The former provides a transition between a round former and a rectangular former so that the material used to form the bag is initially wrapped into a tube around a round former so that the material does not tear on the corners of the former. The round tube of material is then drawn down over the former of the invention to change the round tube to a rectangular tube that may be formed into the bag.

Abstract: A stand up bag having a flat bottom is formed from a weldable material. The bag includes a seam that closes the bag's bottom wall. The seam is welded flat so that the bag is free of protruding elements. A method for manufacturing the bag includes the step of overlapping the leading edge of a tube and welding the overlapped edge to form the flat, welded seam that allows the bag stand on end in an open condition. The apparatus for manufacturing the bag includes a former that may be moved between retracted and expanded positions with an actuator. The former holds the lower portion of the bag in an expanded position while clamp plates form the overlap seam. A bottom welder is used to weld the overlap seam while the clamp plates hold the bottom of the bag against a portion of the former.

Abstract: A detector for continuously monitoring the integrity of a coating on a piece of material. The detector includes an upper bar and a lower bar held near the surfaces of the material. Each bar carries multiple conductive probes in contact with the corresponding surface and electrically connected to an electronic detection circuit. Adjacent probes are connected to electric terminals having different voltage potentials. When probes from the same bar carrying different voltages short together, such as by contacting the surface of conductive sheet material, the detection circuit signals an insufficiently coated area has been found. The short between probes must be large enough to cause a short for more than a predetermined time. The upper probe bar is rotatable to prevent damage to the upper probes by a bent edge on a sheet of material.