Abstract: Disclosed is a conveyor roller comprising a shaft, a plurality of bearings provided on the shaft, and a roller body having a cylindrical side surface and two exterior end walls, the body being fixed to the bearings, and being rotatable on the shaft, wherein the roller body is made with a moldable polymer concrete material, and contains an encapsulated labyrinth seal connected to the shaft, the seal being provided inside each end of the roller body at a position on the shaft separated from the bearings and each exterior end wall of the roller body, such that the seal isolates the bearings from exterior contaminants. The roller according to the invention is more resistant to contamination, and therefore is more durable.