A device to form a honeycomb has an upper continuous belt and a lower continuous belt disposed in parallel and carrying opposing cores. The belts act on liquid wax which is injected into an inlet of the device, with both belts moving in opposition. The inlet has in succession: a scraping zone disposed straight with respect to the upper belt; a zone for opening the cores, which has a certain curvature designed to receive a first injection of wax; and a third straight zone for sealing and expelling any excess wax. At an exit of the device, the longest length of the upper belt has multiple groups of magnetic and non-magnetic rollers for a local curving of the belt to progressively release the honeycomb.