Automatic Painting of Windows and Doors on Conveyor

Lesta EasyProg PORTAL is a fully automatic painting system for windows, frames, doors, panels and cylinders, designed for systems equipped with an overhead conveyor: this is in fact the essential requirement for its operation, since the system recognizes parts while they are moving, hanging in line.

The heart of the system is a vertical scanning gantry fitted with photoelectric barriers: each part hooked to the conveyor passes through it and is scanned in its actual position. At that instant, the software instantly generates the optimal painting path, which the robot executes immediately afterward in complete autonomy, without any manual intervention on the program.

Unlike systems that require dedicated programming for each part type, with EasyProg PORTAL it is enough to create the painting recipes just once, directly from the Robot Controller screen: they will then be recalled automatically by barcode scanning or touch-screen, every time a part of the same type passes through the gantry.

The system is designed to recognize windows, frames, moldings, doors, panels, cylinders or similar parts, and is compatible with industrial painting and finishing systems using both liquid and powder. The gantry scanner is not compatible with ATEX environments and must be installed outside the painting booth.

How automatic painting of windows and doors on conveyor works

Once the part’s geometry has been scanned, the software processes the painting path based on the selected recipe. Each recipe defines the spraying strategy, distinguishing between outer edges, inner edges and front surfaces, and for each element it is possible to set parameters such as speed, distance, gun angle, gun swings, number of guns, opening and shading, as well as optional parameters such as flow rate, atomization and fan pattern.

The reading barriers have a maximum resolution of 5×5 mm and can handle parts up to 3×3 meters, hooked using hangers with a section diameter of no more than 10 mm. The system can also paint battens, glazing beads and similarly shaped objects, provided they are supported with suitable hooks or fixtures: above 10 mm in diameter the area is painted correctly, while below this threshold an unpainted area must be planned at the support point.

To ensure correct scanning, parts must not swing during transit through the gantry, since oscillations would compromise accurate reading of the geometries; any holes present in the parts must also be covered, to prevent the scanner from interpreting them as edges to be painted. The laser barriers and photocells must be protected from direct sunlight exposure, which could worsen scan quality, and a part tilt relative to vertical, in the direction of travel, of +/-15° is allowed.

EasyProg PORTAL in Lesta systems

EasyProg PORTAL finds natural application in Lesta’s complete industrial painting systems equipped with an overhead conveyor, where it automates painting path generation for windows, frames and doors in continuous transit, without requiring stops for robot programming. The system thus fits into lines dedicated to automatic door painting, where the variety of formats and shapes makes manual part-by-part programming inefficient.

For processes that instead do not involve an overhead conveyor, but a positioner onto which the part is loaded, Lesta also offers Easy PROG 2D and Easy PROG 3D Scan, the versions of the EasyProg family designed respectively for panels and drawers of known height and for three-dimensional parts of more complex shape. Thanks to these solutions, Lesta is able to offer automatic painting of windows and doors on conveyor as well as on positioner-based systems, covering the different production needs of its customers.