Abstract: A system for sealing the edges of assembled sandwiches of two sheets and a peripheral spacer has a first and a second conveyor extending parallel to each other through respective sides of a sealing station for displacing respective successions of the sandwiches therethrough. Respective first and second stops in the sides of the station position the sandwiches of the respective sides longitudinally and transversely therein. A transverse support extends across the two sides and is displaceable longitudinally in the station. A sealing device displaceable transversely along the support is engageable with the edges of the sandwiches in the sides of the stations for sealing same. This system is operated by displacing the device on the support and the support in the station to move the sealing device first around a sandwich in the one side of the station and then around the sandwich in the other side of the station.