Abstract: A transport system for producing panels of synthetic-resin foam sandwiched between a pair of skins comprises a pair of transport belts carried on a frame having respective parallel stretches each engaging a respective skin. The belts are driven at rates such that the stretches advance in a transport direction at a belt speed. A pair of roller chains is provided inside each of the belts with a plurality of rollers extending between each of these pairs of chains. These roller chains are connected to another drive system that advances the rollers counter to the transport direction in engagement with the stretches so as to minimize lateral deflection of the belts during production of a synthetic-resin panel formed by injecting a foamable synthetic resin between the skins and allowing it to harden while it moves between the working stretches.