A heat sealing packaging machine and method for assembling that includes a package platform for supporting a package, a film carriage carrying a supply of film material, a sealing platform adjacent the package platform and including a conveyor for laterally moving the package to be sealed to a shrink tunnel. The carriage is laterally movable to adjust the position of the film material and a lifting mechanism raises and lowers the sealing platform and the shrink tunnel. The shrink tunnel is laterally movable with respect to the sealing platform and includes a latch mechanism for locking a lateral position of the shrink tunnel.