Immediately downstream of the dye-edge machines, in the production laboratories of leather goods some ovens or dryers are installed to allow the semi-finished parts to proceed through the next step, in fast sequence. A special configuration of these units is used to dry the color applied on the edges of parts of bags and folders or already assembled final products, such as bags, folders, briefcases and small leather goods in general. Another unit type is represented by a configuration for horizontal and vertical belts and the like.