We decided we needed a simple hand tool. I created a tool with four aluminum corners with two cartridge heaters in each corner in order to deliver enough heat quickly. (This drawing only shows one heater per corner) The four corner blocks are each mounted on a parallelogram so that pressure will be evenly distributed. The operator, after adjusting the temperature setting, simply places the repair tool into the lunchbox and presses down for 15 to 20 seconds or until the corners have been reformed and the glue has set. The beauty of this tool is that it requires only hand pressure and the timing for each bag repaired is adjusted as needed by the individual operator.
This is what the problem looked like before repairs.
This is what the repaired product looked like.
Here you can see how the four corners operate in parallel and tandem. Hmm... is that the right word? Tandem applies to two things operating together is there a word that applies to four things operating in, concert? In unison? Anyway you get the idea.