Abstract: Organic contaminants are removed from water by microbial biodegradation in a stirred tank system having a powdered or granular media for biofilm support. A stirring impeller maintains the media suspension, provides a shear force to remove excess biomass from media particles and is adjustable to provide an optimal biofilm thickness.

Abstract: A method for adhering a coating material to at least one surface of a densified random-fiber composite sheet is provided. The method comprises applying sufficient heat to a surface of the composite sheet to form an activated surface whereby the fiber component of the sheet is projected outward from a plane defined by that surface, and contacting the activated surface with the coating material. The coating material is generally of a viscous or liquid nature such that it can physically interact with the projected fibers to adhere thereto. A method for adhering asphalt to a metal substrate employing a densified random-fiber composite sheet is also provided wherein the metal is coated with an adhesive and then adhered to an activated surface of a composite sheet. Asphalt is then coated onto the exposed surface of the composite sheet which has been activated or is activated by coating with hot asphalt.

Abstract: Laminate structures are prepared having a substantially non-reinforced polymer core and outer layers comprising a resin containing randomly oriented reinforcing fibers from about 0.06 to about 2 inches in length. In addition, a process for preparing such laminates is disclosed.

Abstract: A metal-plastic-metal structural laminate which can be formed into various useful articles having compound curves using conventional metal forming techniques. The laminate comprises two metal skin layers and a centrally disposed polymer layer comprising a core layer, and optionally first and second adhesive layers. Each metal skin layer is 2 to 20 mils, the ratio of the core thickness to skin thickness is less than 9:1 and the total laminate thickness is 5 to 65 mils. The laminate can be bent to 90.degree. to a critical radius, the distance between the pivot point and the inner skin surface of the laminate, without metal rupture.

Abstract: An improved cutter for hot plastic strands is provided which uses an inwardly extruding frustoconical die and corresponding frustoncnical cutter rotating within the die. Severed particles are fluid cooled and cutter clearance is readily controlled even when a cutter has been reground for sharpening and the diameter reduced.

Abstract: A simplified screen changer is provided which is particularly suitable for the extrusion of synthetic resinous thermoplastics. Screens are supported in a recessed movable plate. The screen on the upstream side is sealed against leakage by means of an extrusion pressure actuated sealing ring. The apparatus is of simple and rugged construction.

Abstract: An improved cryogenic tank is provided which has insulation secured to the inner surface of the tank and a relatively thin sealing membrane within the tank to contain cryogenic liquid. Space containing the insulation is maintained at a reduced pressure sufficient to maintain the insulation in engagement with the outer tank wall.