Device for powder based additive material manufacturing of dental appliances

A device for powder based additive material manufacturing of dental appliances, comprising:

• a build area and a recoater for providing a powder layer to the build area, the recoater comprising a slide and being adapted for dispensing of the powder to the build area, wherein the recoater has at least two powder supplies for individually supplying a first and a second powder on the slide and a powder transport section in which the first and second powder are brought in touch with each other for at least partially merging, wherein each powder supply has an outlet, and wherein the powder supply outlets are arranged adjacent each other, wherein the slide has a generally planar powder receiving surface terminating at one end in a dispensing edge and extending under the at least two powder supply outlets, wherein the device is adapted such that a vibration of the slide supports powder deposited on the powder receiving surface to slide toward the dispensing edge;
• wherein the slide receives the at least two powders side-by-side along a dimension parallel to the dispensing edge to form at least two corresponding powder tracks;
• wherein the at least two powder tracks partially merge at their lateral margins in a direction transverse to the direction of flow to form transition zones between the at least two powder tracks.