Abstract: A rotary biological contactor for treating waste water comprising a center core or shaft and a plastic media on the shaft and arranged in a multiplicity of modules spaced from each other, each module including a multiplicity of turns of plastic sheet material with edges at the ends of the module, the turns of plastic sheet material having elongate undulations extending obliquely of the rotation axis and of the ends of the module, adjacent turns of the plastic sheet material having the undulations extending transversely of each other so that each elongate undulation traverses a multiplicity of undulations of the next adjacent turn, each undulation being welded to the undulations of the next adjacent turn at each place where the undulations touch each other, and the plastic sheet material also having circumferentially extending zones or bands traversing the undulations and extending transversely of the undulations, the bands being free of such undulating relationship, the several undulations and circumferential

Abstract: A waste water treatment apparatus with a tank through which waste water flows, a rotary biological contactor in the tank with an annular plastic media fixed on a buoyant drum or tubular shaft providing buoyancy to which maintains immersion to the topmost peripheral portion of the drum, mechanical bearings to stabilize the contactor in the water and a drive connected to rotate the contactor.

Abstract: A heat sealing machine for producing a drum of spirally wound layers of thermoplastic polymeric sheet material heat sealed together having a rotatable horizontal shaft for receiving thermoplastic polymeric sheet material spirally wound thereon by rotation of the shaft; a heater adapted to be positioned between and adjoining a first polymeric sheet layer being spirally wound on the shaft and a prior layer wound on the shaft; and a support, for the heater, displaceable with respect to the shaft axis so that the heater can remain radially adjacent a drum surface on which another spiral layer is to be heat sealingly attached. A portion of the heater can be readily formable into cylindrical shell segments of varying radii when positioned between the two polymeric sheet layers.

Abstract: Apparatus for vacuum molding a plurality of three dimensional geometrical shapes in a thermoplastic polymeric sheet having a molding plate, the surface of which has a plurality of three dimensional geometrical shapes, with said molding plate having an enclosing border, a molding face and a non-molding face; a gas orifice extending through the molding plate so that a gas can flow from one face of the molding plate to the other face; a mechanism to move the molding plate along a predetermined path; a mechanism to maintain a thermoplastic polymeric sheet, heated to a plastic condition, adjoining the moving molding plate molding face; a mechanism to releasably seal the heated polymeric sheet to and all around the molding plate border; a vacuum source to remove gas, from between the heated polymeric sheet and the molding face of the molding plate, through the gas orifice whereby exterior pressure can force the heated sheet against the molding face surface; and a mechanism for removing the molded sheet, after it co