Abstract: A flange folding machine for folding the distal end of the flanges of a blister package or the like inwardly upon the proximal ends thereof to form closure panel receiving channels. The machine comprises, a plurality of carriers mounted on a conveyor for continuous movement through a folding station, a side flange folding mechanism, a first heater located in close proximity to each first fold line and being operable to heat the side flanges to a sufficient extent to render them formable. The mechanism may also include a leading end flange forming mechanism for folding the distal end portion of a leading end flange inwardly upon the proximal end portion thereof along a transverse foldline. The leading end flange forming mechanism comprises a second heater which is mounted on a carriage which is slidably mounted for reciprocating movement in the folding station to and fro along between a forward position and the retracted position.