I spoke with one customer that was bending acrylics for displays that would heat one side, flip it over and repeat the process until it was malleable enough to bend. This was a great idea, but he would get a slight ripple at the bend point. There is a better solution: by adding a second heating element to an upper frame that could be lowered close to the substrate, both sides of the plastic could be heated at once. This also ensures an even heating temperature, avoiding ripples in the material and making the bends twice as fast, plus you can bend thicker plastics, up to 15mm.
—Sean Lanigan, modico US Corp. and Ovili US LLC