A poly bubble bag filling machine, seal head, bag magazine, and a carton are described. The filling machine includes the bag magazine which is configured to hold and advance a plurality of pre-formed poly bubble bags as they are retrieved for filling. The carton provides simple handling and replacement of bags in the magazine and enables operation of the magazine while the carton is in place. A bag-transfer carriage transfers bags from the magazine to the seal head. The seal head includes suction bars configured to enable application and retention of a sufficient suction force to sides of the bag to open and retain the bag during filling. Sealing bars are positioned near the suction bars and are operable to seal the bag closed via application of heat.