| 摘要 |
A method for laying down a continuous, predetermined pattern of granular material upon a substrate (12) includes providing at least one station (S1, S2) including a rotating drum (18) with a drum wall (20) defining a limited retention region (34) under vacuum, and a plurality of through-apertures (36) arranged in an element of the desired pattern. Granular material (G) applied to the surface (22) of the drum is held by vacuum in the desired pattern. After removal of excess granular material, the vacuum is discontinued causing the granular material to disengage from the drum surface and pass, by force of gravity, onto the surface of the substrate moving relative to the station in the form of the predetermined element of the desired predetermined pattern. An apparatus (10) for laying down a continuous, predetermined pattern of granular material upon a substrate is also described.
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