Abstract: A method and apparatus for forming cured polyethylene insulation about high voltage cables by applying uncured polyethylene around a core of the cable. The polyethylene is heated, cured and then cooled to room temperature in a pressurized nitrogen gas atmosphere. In one form the molding apparatus comprises first and second mold forms which define a cavity and which include means for heating the mold halves to the polyethylene curing temperature. Means is also provided to introduce the pressurized nitrogen into the cavity and for subjecting cable portions that extend beyond the mold to pressurized nitrogen until such cable portions are sufficiently cooled to prevent their deformation under pressure, to prevent the oxidation of polyethylene and/or to prevent the formation of voids or enclosures.

Abstract: After extrusion tubular profiles of thermoplastic material are sized and cooled by the overpressure method. The internal pressure is produced and cooling effected by evaporation in the hollow space of the profile of a chemically inert liquefied gas having a critical temperature in the range of from -150.degree. to +35.degree. C.

Abstract: A method of continuously and rapidly effecting a heat induced cure in curable polymeric compositions, such as by cross-linking or vulcanization, by means of directly contacting a surface of the heat curable polymeric composition with a stream of hot gas traveling at very high velocities, and under elevated pressures.

Abstract: Two mold halves together form a mold cavity and one of the mold halves is fitted with a plurality of ejector rods that can be reciprocated so as to push a molded article out of that half. At least some of these ejector rods are formed with throughgoing passages terminating adjacent the inner ends thereof at nozzle openings. Air and a treatment fluid, such as a demolding liquid, can be injected into the mold interior through these rods, the nozzle openings in the ends of the rods being covered during the normal molding operation.

Abstract: A method for making tires. The tire is first formed in two or more parts from uncured rubber, in mould cavities provided with locking sprues to retain the moulded tire part in a desired section of the moulding. The mould is pressurized, at least when moulding the tire sidewalls, then opened and the moulded uncured tire parts carried in parts of the mould are brought together and joined under heat and pressure.

Abstract: A semipermeable membrane is obtained by casting a cast solution comprising a mixture of a water-insoluble high polymer and a water-soluble high polymer, a mixture of a water-insoluble high polymer and a water-soluble surfactant or a mixture of a water-insoluble high polymer, a water-soluble high polymer and a water-soluble surfactant to form a shaped article, exposing the thus formed shaped article to a plasma to crosslink the surface thereof, and then washing the exposed article with water to remove uncrosslinked water-soluble high polymer or water-soluble surfactant. The membrane can be used for such substance separation methods as reverse osmosis, ultrafiltration and the like.

Abstract: An open pore liquid purification apparatus containing semipermeable membranes, is made by: (1) placing a module, made of bonded, resin coated filler particles, having a plurality of spaced circular bores therethrough, in a stationary vertical position, (2) placing a viscous casting composition into each of the bores, the composition containing 10 parts polysulfone resin and 10-40 parts of an organic solvent, the solvent being effective to homogeneously disperse and partly dissolve the polysulfone, (3) gravity dropping a casting bob, having a circular cross-section at its widest point, down through each bore to form a continuous film of casting composition on the inside of each bore, and then (4) immediately exposing the film to a low humidity atmosphere, and (5) contacting the film with a suitable leaching liquid, to form a polysulfone ultrafiltration membrane on the inside of each module bore; the membrane being resistant to solvents and operable at a pH of about 1 to 12 and a temperature of about 5.degree.

Abstract: A method for drawing silica fibers utilizing an electrical resistance furnace includes the steps of heating a preform so that it begins to flow forming a fiber; pulling the fiber from the furnace; and flushing the preform and the fiber within the furnace with counteracting inert gas flows, the gas flows protecting the preform and the fiber from contamination.Apparatus used with the above-described method is also disclosed.

Abstract: A method for curing vulcanizable elastomeric articles positioned between a mold surface and a pressure chamber including the steps of introducing into the chamber a hot fluid of relatively high heat capacity, e.g., steam, under pressure for a sufficient period to soften the article, introducing into the chamber a gas of relatively low heat capacity and pressurizing the gas in the chamber at a pressure substantially greater than the pressure under which the hot fluid was introduced, and thereafter vulcanizing the elastomeric article.

Abstract: A method of producing hollow articles of plastic material by blow molding is characterized by blowing compressed air into the preform at the beginning of the admission phase to intensify the inflation operation and its admission is interrupted before the final blow pressure is reached.

Abstract: A process is provided for manufacturing a product which has a fibrous surface and is formed by the conversion of a non-fibrous polymer, which process comprises placing a polymer between drawing surfaces which adjoin the polymer and adhere thereto and separating the surfaces. At least one of the surfaces is formed by a carrier for the polymer and for the fibers, through which carrier a fluid is blown such as to flow around the fibers in statu nascendi and orient and stabilize them as their viscosity increases. An apparatus for carrying out said process is also provided.

Abstract: Solid particulate materials are bonded together to form a foundry mold or core byI. forming a mixture of the particles and an anaerobically-curing adhesive and moulding the mixture to the desired shape, andIi. causing the adhesive to cure and bond the particles together by maintaining the shaped article in a substantially oxygen-free environment.The anaerobic adhesive may comprise, as monomer, an ester of an acrylic acid, with a hydroperoxide or peroxide as a polymerization catalyst, and the oxygen-free environment may be produced by displacing air with nitrogen or other inert gas or vapor.The method described is particularly suited for the production of foundry moulds and cores from sand or other particulate material.

Abstract: Polytetrafluoroethylene bags used in solids filtering units are preshrunk to preclude tearing or ripping of the bags.

Abstract: A machine for producing tubular fastener sealing members having rolled ends includes an apertured guide member cutting block backed by a pair of clamp members and which feeds tubular stock of resilient material between the clamp members through the guide block. A rotating knife is associated with the guide block and an axially reciprocating rotating shaft supports an edge rolling tool confronting and coaxial with the guide aperture. The components are motivated and sequenced to open the clamp until the tube is advanced to the tool, close the clamp, advance the tool to roll the tube leading edge, open the clamp and retract the tool which is followed by the tube, close the clamp, further retract the tool, and slice the finished product from the tube stock.

Abstract: In a method for injection moulding of the type wherein gas or vapor evolved from the resin being moulded is vent through a vent opening provided for a heated cylinder at an intermediate point thereof, the vent opening is maintained at a reduced pressure during metering and a small quantity of vaporizable liquid is admitted into the vent opening during injection for increasing the pressure therein.