Abstract: Apparatus for supplying granular and pulverous thermoplastic materials, duroplastic materials, rubber, or similar materials to processing machines, such as extruders. The apparatus includes a charging hopper with conduit-like devices for withdrawing gases which are released from the material. A plurality of vacuum connections arranged one above another respectively degas pertaining layers of the material which is in the hopper.

Abstract: A vent for a devolatilizer includes a means defining a vent opening in the cage of the devolatilizer and a vent duct which communicates with the vent opening. Gas escapes into a cylindrical vent chamber in the vent duct. The chamber is cleaned by a vent screw which is rotated in the chamber and which includes a screw body of minimal diameter and a helical screw flight portion of a pitch which is sufficiently large such that the velocity of the vapor leaving the cage through the vent duct is maintained below a predetermined maximum vapor velocity. This maximum vapor velocity is set such that the amount of fine material which is entrained in the escaping vapor is minimized. A vapor return duct is connected to the vent chamber for extracting vapor from the chamber so that it may be recycled or disposed of.

Abstract: Injection molding apparatus is disclosed for molding degradable synthetic resinous materials such as nylons. A vented injection molding machine includes a barrel, a rotatable reciprocable screw and means for preventing ingestion of a deleterious atmospheric gas such as oxygen. The particular apparatus whereby exclusion of the atmospheric gas may be effected includes a conduit having a terminal end thereof positioned at the vent opening of the injection molding machine barrel. The conduit communicates with a source of inert gas and directs a pressurized current of inert gas into the vent opening during the transient time interval between the end of the injection portion of the molding machine cycle and the plasticization portion of the machine cycle. If desired, the inert gas may flood the vent opening continuously. Both nitrogen and carbon dioxide are suitable inert gases for use with nylon materials.

Abstract: A powder compacting machine for compressing a mass of powdery material to produce substantially flaky articles of substantially uniform thickness is constituted by a hopper unit having a built-in screw feeder and a pair of opposed compressing rolls. One of the compressing rolls is supported for movement close to and away from the other of the compressing rolls. The hopper unit has a hopper, which may be connected to a source of vacuum, and, on the other hand, one of the compressing rolls has a shape complementary to the other of the compressing rolls so that a substantially uniform thickness of the flaky articles made by compressing a mass of powdery material can be obtained. The machine also has at least one barrier employed to substantially uniformly dispense a mass of powdery material falling towards a clearance between the compressing rolls.

Abstract: Apparatus for separating a substantially insoluble liquid from a mixture containing a polymer or polymer mixture. The liquid is a vapor at the usual temperature and pressure of the polymer extrusion operation and is kept in liquid form by providing a high pressure region in the extruder. A liquid outlet is provided upstream of the high pressure region and the liquid is maintained under pressure and taken off as a liquid. The pressure restricting means may be a liquid outlet provided with a pressure control valve, trap or the like.

Abstract: Soap worked in a plodder with introduction of a color dye for color striation of the extruded column is extruded through a die plate that has a rectangular opening corresponding to the major face dimensions (length and width) of the product bar so that the extrusion grain is perpendicular to the major faces, and the extruded column is severed at distances equal to the product bar thickness to provide blanks that are pressed in a direction parallel to the extrusion grain to form the product bar. Special locations for color introduction are provided and a unique "carrara" marble effect is produced in the bar.

Abstract: A method and apparatus are disclosed for the production of injection molded products from synthetic resinous materials, such as nylon, which tend to be degraded when exposed to oxygen while they are heated to the temperatures required for injection molding. The apparatus includes a barrel having a discharge opening, a screw receiving bore and a vent opening between the feed opening and the discharge opening. A two stage rotatable reciprocable screw is mounted in the bore and includes a vented portion in registry with the vent opening. Water vapor and volatiles are generated during plasticization in the first stage of the screw, and evolve as the material enters the vent section of the second stage. The vapors are exhausted through the vent opening. The vent opening is provided with a check valve which readily permits the exhaust products to pass from the screw receiving bore. However, the check valve effectively prohibits the entrance of atmospheric air through the vent opening to the vent section.

Abstract: A device for degassing plastic materials comprising an extruder including at least three parallel screws intermeshing in pairs, arranged in a casing which follows the periphery of the screws and arranged around a central stem, the surface of which also follows the periphery of the screws so that the screws are encased over a substantial part of their periphery. The casing is provided with a supply inlet, an end plate through which degassed material is extruded and a degassing outlet through which gases are withdrawn, the degassing outlet being upstream with respect to the supply inlet.

Abstract: An extruder of the degassing and modification type, comprising a cylinder having at least one hopper orifice and at least one vent opening, and two adjoining screws mounted in the cylinder to be rotated in opposite directions. Each of the screws are formed by at least one feed section to be disposed below the hopper orifice, a kneading section, at least one mixing section to be disposed below the vent opening and a pressurizing section, and one of the screws is further formed by a metering section in series with the pressurizing section. Respective sections except for the kneading sections are generally formed from continuous flights and the flight angles are made different between the adjoining screws. The kneading sections are respectively provided with an adjusting ring and a gate ring arranged at a distance and a number of pins secured to the screws between the rings. Water may be introduced into the kneading section.

Abstract: A rotary screw extruder and a method are provided to both devolatilize and dry plasticized resinous hygroscopic materials during extrusion thereof into a finished product of indefinite length. The extruder includes a screw having three successive pumping sections and a pair of vent sections. Each vent section separates two of the successive pumping sections. The first pumping section meters plasticized material throughflow. The intermediate pumping section has partially full channels that permit a continuous, helical passage to interconnect the two vent sections. The partially full channels establish a free surface which promotes devolatilization and drying. The third pumping section pressurizes the devolatilized and dried plasticized material for extrusion through a conventional die orifice. The devolatilizing and drying method begins by controlling the flow rate of plasticized material into a gas removal zone.

Abstract: Means and method are provided for feeding through a feed port, to a plasticized polymer mass, a powdery material which contains entrapped air. An extruder is used having an entrance for feeding the polymer, and having a rotating worm, transporting the polymer from its entrance to a polymer exit; means are provided forming an entrance port for the powdery material downstream of the polymer entrance, and positive vent means are provided in the housing upstream of the powdery material entrance but downstream of the polymer entrance for drawing out the air, to prevent entrapped air or volatiles from fouling the powder feed port.

Abstract: Dilute polymer solution (about 5 to 50% by weight of solid polymer) is heated and flashed in a concentrator, is delivered to an extruder at a concentration of about 30 - 80% by weight of solid polymer, further solvent is vaporized and vented off, and the solid polymer material is subjected to counter-current fluid flow in single or multiple stages, with back pressure control at the polymer exit.