Recoating unit, recoating method, device and method for additive manufacturing of a three-dimensional object

Abstract

A recoating unit () serves for equipping or retrofitting a device () for additive manufacturing of a three-dimensional object () by selectively solidifying a building material (), preferably a powder, layer by layer. The device () comprises a recoater () movable across a build area () for applying a layer () of the building material () within the build area () and a solidification device () for selectively solidifying the applied layer () at positions corresponding to a cross-section of the object () to be manufactured. The device () is formed and/or controlled to repeat the steps of applying and selectively solidifying until the object () is completed. The recoating unit () comprises at least two recoating rollers () spaced apart from each other in a first direction (B) and extending into a second direction transversely, preferably perpendicularly, to the first direction, and a compacting and/or smoothing element () arranged between the two recoating rollers () in the first direction (B) and extending into the second direction. The recoating unit () is adapted to draw-out building material to a regular layer (), depending on the movement of the recoating unit into the first direction (B) or into its reverse direction (B), using the recoating roller () arranged ahead in the respective moving direction (B, B), and to compact or smoothen the layer () drawn-out by the recoating roller () arranged ahead using the compacting and/or smoothing element ().