a method and apparatus for improving the flow of a powder from a source , such as a large hopper , to the intake of a conventional machine wherein such powder is compressed into tablets . devices are arranged along the route of powder flow so as to restrict , decelerate and depressurize such powder flow and thereby prevent its surging , compaction and / or bridging . these devices are also arranged to maintain the powder in a loose condition of uniform density . in the preferred embodiments , said devices include most or all of a return duct to the powder source , an upper filter to atmosphere , an upper baffle against which the powder is directed , a restriction , an elongated powder tube through which the powder flows , a lower baffle and a final pressure relief filter to atmosphere . mechanism in the tableting machine receives the thusly prepared powder and forms it into tablets much faster than previously possible . also , said devices increase substantially the range of materials , including powders and granules , which can be compressed into tablets .