Machine for forming seams of two-piece paper cups

摘要

In a machine for making two-piece flat bottom paper cups, having a mandrel on which the cup is formed, the portions of the two blanks that are to form the bottom seam are heated by a device comprising a stationary air duct with which the mandrel can be coaxially aligned. Air flowing forwardly in the duct from an inlet at its rear is heated by an electric element therein. On the front of the duct a nozzle is mounted to slide between a forward operative position and a rearward inoperative one. Cooperating throttle elements on the nozzle and the duct restrict flow to radial outlets in the nozzle when it is in operative position, ensuring steady air flow through the duct. An annular heat shield around the nozzle enables it to effect combined radiant and hot air heating. All heaters are arranged for retraction if the machine stops for longer than a normal dwell period.