A coating system for applying at least two paint layers on plastic material containers, comprising: - a loading/unloading station for loading containers onto a transfer chain and for unloading the containers themselves from said transfer chain once a coating process of said containers is completed; said transfer chain being adapted to run along a closed course within said system so as to pass through: - at least one paint application station, adapted to apply the at least two paint layers on said containers, - a first drying-reticulating oven for a first of the at least two paint layers applied onto the containers in a passage of the transfer chain in the at least one paint application station, said first drying-reticulating oven comprising one or more thermal treatment tunnels, defining a first longitudinal axis, subdivided into at least four sectors in cross section with respect to said first longitudinal axis and incorporating thermal radiation emission means arranged in at least one of said at least four sectors, - a first opening in a tunnel wall for the entrance of a first flow of air in the one or more thermal treatment tunnels; - forced ventilation means adapted to produce second partial flows and to deviate each of said partial flows within a respective sector comprising at least one fan impeller, arranged in a central area of the drying-reticulating oven or of the single thermal treatment tunnel, allowing a uniform distribution of the air to the sectors of the drying-reticulating oven, by exploiting the symmetries and the different configurations envisaged by the internal structure of the drying-reticulating oven; wherein the coating system comprises - a second drying-reticulating oven for a second of the at least two paint layers applied onto the containers in a passage of the transfer chain in the at least one paint application station, said second drying-reticulating oven comprising one or more thermal treatment tunnels defining a second longitudinal axis, subdivided into at least four sectors in cross section with respect to said second longitudinal axis and incorporating thermal radiation emission means arranged in at least one of said at least four sectors wherein said first and second drying-reticulating ovens (14, 14') respectively comprise a first thermal radiation emission portion (15, 15') and a first air conditioning portion (16, 16') adapted to dry/flow the paint on the containers, and a second air conditioning portion (17, 17') and a second thermal radiation emission portion for completing polymerisation of the paint, wherein the transfer chain is adapted to move within the drying-reticulating ovens (14, 14') in said respective at least four sectors, on two lower and higher levels, each comprising a bank (20, 20', 20", 20"', 50, 50', 50", 50'") each of which is connected to the subsequent one by curved segments and adapted to position the containers with their longitudinal axis in essentially horizontal position within said drying-reticulating ovens (14, 14') and in essentially vertical position outside said drying-reticulating ovens (14, 14'), wherein the at least one fan impeller in each one of the drying-reticulating ovens is arranged essentially between the upper (20", 20"', 50", 50"') and lower banks (20, 20', 50, 50'). - a loading/unloading station for loading containers onto a transfer chain and for unloading the containers themselves from said transfer chain once a coating process of said containers is completed; - at least one paint application station, adapted to apply the at least two paint layers on said containers, - a first drying-reticulating oven for a first of the at least two paint layers applied onto the containers in a passage of the transfer chain in the at least one paint application station, said first drying-reticulating oven comprising one or more thermal treatment tunnels, defining a first longitudinal axis, subdivided into at least four sectors in cross section with respect to said first longitudinal axis and incorporating thermal radiation emission means arranged in at least one of said at least four sectors, - a first opening in a tunnel wall for the entrance of a first flow of air in the one or more thermal treatment tunnels; - forced ventilation means adapted to produce second partial flows and to deviate each of said partial flows within a respective sector comprising at least one fan impeller, arranged in a central area of the drying-reticulating oven or of the single thermal treatment tunnel, allowing a uniform distribution of the air to the sectors of the drying-reticulating oven, by exploiting the symmetries and the different configurations envisaged by the internal structure of the drying-reticulating oven; wherein the coating system comprises - a second drying-reticulating oven for a second of the at least two paint layers applied onto the containers in a passage of the transfer chain in the at least one paint application station, said second drying-reticulating oven comprising one or more thermal treatment tunnels