Abstract: A paper box folding and sealing machine for forming a hemmed edge. A skiving station removes a portion of a carton blank material at the area to be hemmed. A hemming station folds the skived portion onto the blank, irons it and then opens the hem to lie in a predetermined plane that intersects the plane of the blank. Superheated air directed in a laminar-like air flow, activates a thermoplastic coating adjacent the skived portion of the area to be hemmed. Folding fingers, tack rollers and presser rollers then fold the skived portion onto the activated thermoplastic coating to form a hem that is sealed against the adjacent portion of the blank.

Abstract: Apparatus for a paper box folding machine for folding the trailing panels of carton blanks about fold lines as the blanks travel individually and successively along a paper line. A servomotor running continuously at a relatively constant nominal angular velocity drives the input shaft to an indexer that controls, for each position of its input shaft, the angular position of its output shaft. The indexer converts continuous input from the servomotor to discontinuous motion of its output shaft. The output shaft lies below and transverse to a paper line. Radially extending fingers mounted on the output shaft are positioned below a trailing panel as the carton blank passes. The indexing means output shaft and fingers rotate rapidly so the fingers engage and fold the trailing panel and then dwell to allow the blank to exit the apparatus. Then the shaft and fingers move below the paper line to allow another blank to enter and rotate to engage a next blank in sequence.

Abstract: A method and apparatus for the manufacture of folded paper boxes with a hemmed seal. One of two edges to be overlapped is skived and folded into a hem. After the edges are locally heated, blanks move individually and successfully along a conveyor for folding and sealing. Just before sealing, the hemmed edge passes between a hem holder and the conveyor to maintain the hemmed edge. The hem holder is heated to prevent the edges from cooling. In one embodiment hot air directed onto the hem from the hem holder forms an air cushion between the hem and the hem holder thereby to minimize any contact between the hem holder and the blank.