Abstract: A bag making machine automatically cuts off and seals plastic from a web of film in register with regularly spaced eyemarks. A correction system is disclosed for use when the film gets out of register with the eyemarks. When the correction system is activated, the film is advanced to the next eyemark. The bag making machine resumes normal in-register operation without ever shutting off the machine. A method of correcting lengths of bags being formed from a web of material is further disclosed.

Abstract: A separator/folder bag machine for developing individual, folded, plastic bags. A pair of high speed separation rollers, actuated by means of a servo motor driven eccentric linkage, engages a continuous plastic web to separate individual plastic bags formed tin the web. A pair of parallel, wide belts, and a pair of similar, overlying belts, engage both sides of the separated bags and transport the bags to a plurality of folding stations. Air jets at selected locations in the folder/separator controllably direct the bags through pairs of nip rolls to fold the bags along predetermined fold lines. Sensors in the folder/separator sense abnormal conditions and deactivate particular fold stations to reject improperly formed bags. A two speed slowdown mechanism at the discharge end of the separator/folder slows the folded bags to facilitate downstream handling.

Abstract: A bag machine fabricates plastic bags by transversely cutting and sealing, at regularly spaced preselected locations, an elongate plastic web having graphic material repetitively printed thereon. In operation, the bag machine advances the web by a calculated draw length, and an optical sensor, sensitive to the passage of eyemarks printed in regularly spaced locations on the web, functions to ensure that the web is cut and sealed only at the desired locations. To avoid inaccuracies resulting from a gradual variance between the nominal draw length and the actual distance between eyemarks, a control system monitors the actual distance between eyemarks and sets the nominal draw length to the average actual spacing between eyemarks as measured over a preselectd number of successive eyemarks.

Abstract: A bag machine fabricates plastic bags by transversely cutting and sealing, at regularly spaced preselected locations, an elongate plastic web having graphic material repetitively printed thereon. In operation, the bag machine advances the web by a calculated draw length, and an optical sensor, sensitive to the passage of eyemarks printed in regularly spaced locations on the web, functions to ensure that the web is cut and sealed only at the desired locations. To avoid inaccuracies resulting from a gradual variance between the nominal draw length and the actual distance between eyemarks, a control system monitors the actual distance between eyemarks and sets the nominal draw length to the average actual spacing between eyemarks as measured over a preselectd number of successive eyemarks.