Abstract: A cyclone separator for separating heavy particles and dust particles from fibre material. The separator includes a cyclone housing (2), an inlet tube (9) that opens substantially tangentially into the housing (2), an overflow pipe (6) for the removal of cleaned light-weight fibre material, and an underflow outlet (4) for discharging heavy particles and dust particles. To improve dust removal, a sieve member 7, 8 is arranged inside housing (2) substantially co-axial with the housing axis and into which inlet tube (9) opens tangentially. Additionally, pin-studded or spike-studded strips are mounted on an inside face of the cyclone housing or of the sieve member to preliminarily open up the fibre material. A coaxial sieve member having flat bars with vertical upper portions and inwardly-curved lower portions that bound a co-axial lower sieve opening is also provided.

Abstract: A screen drum and a method for its manufacture is disclosed wherein the screen drum comprises at least two cylindrical screen members spaced apart, between which a stiffening ring is disposed. The stiffening ring has two cylindrical surfaces which guide the ends of the cylindrical screen members, and a projecting part between them. The cylindrical screen members and the stiffening ring are attached to each other by a weld joint connecting the projecting part of the stiffening ring and the ends of the cylindrical screen members and filling the gap between them.

Abstract: A perforated tube is housed in a chamber in which vacuum is drawn. An air jet is directed into one end of the tube and fiber bundles are fed into the jet which separates and dispenses individual fibers from the bundle, fluffs them, cleanses them of any particulate material, and carries them into the tube. The tube retains the fibers while fiber fragments, undesirably short fibers and particulate matter are drawn by the vacuum and resultant air flow out of the tube through its perforations to a suitable discharge.