Abstract: A foam extrusion apparatus and method in which extrudate is extruded into a sealed chamber which may be subjected to pressure variation such as a vacuum with the controlled shaping of the plastic being obtained by power driven rolls within the chamber downstream of the die. Because of the harsh environmental conditions within the chamber it is desirable that the shaping or forming rolls be driven by an externally powered source which will therefore be not subject to the pressure, vacuum, or other deliterious conditions found within the chamber. Moreover, because of the external position of the drive with regard to the chamber, the entire system need not then be shut down in order to open the chamber and make the required adjustments or repairs. The chamber is preferably the upper end of a barometric leg into which the extrudate passes. The upper end of the chamber is closed by one or more bulkheads which are movable toward and away from the upper end of the chamber.

Abstract: A process and system for the formation of a polymer foam sheet of comparatively uniform biaxially orientation and comparatively uniform dimensions prepared by extruding polymer foam so that it rides on a fluid bearing film between the point of extrusion and a point of diameter expansion of the extruding tube.

Abstract: A method of forming reinforced synthetic articles of polyester resin by reaction injection molding techniques comprising combining a set of reactants including a major base mass of polyester resin in fluid form, at least one polyester cure accelerator, a selected quantity of isocyanate, a surfactant, and an additive that is highly exothermically reactive with at least one other component in the mixture. The isocyanate is added in sufficient quantity to react with at least one other component in the mixture to provide mold filling and shrink-resistant quantities of carbon dioxide throughout the mixture. The resultant mixture is injected into a mold prior to substantial reaction. The additive is allowed to react and the heat produced by this exothermic reaction is effective to trigger and accelerate gas forming soon after injection. The gas formation generates pressure to expand the polyester base resin mass and maintain pressure through the curing reaction of the accelerator with the polyester resin.

Abstract: A shrink-fit article is made by extruding a silane-grafted polymer which foams, at least at its surface, and cross-links. Upon completion of foaming and cross-linking, the article is expanded while (still) warm and cooled in the expanded state.

Abstract: A method for making polyurethanes in a mold that is cooler than usual; i.e., at a temperature less than 120.degree. F., is described. Normally, polyurethanes made in relatively "cold" molds contain numerous surface voids. However, N-alkylmorpholines have been discovered to be effective "cold sink" catalyst additives which permit void-free polyurethane formation even in cooler than average molds. The additive should comprise from about 10 to about 30 wt. % of the entire catalyst portion of the polyurethane formulation.

Abstract: This invention relates to a method of producing a dam comprising the steps of exposing transmission members 4 by stripping the sheath 3 of a communication cable, covering the exposed portions of the transmission members 4 with a mold 5 and injecting self-curing resin 2 into the mold 5 to cure it. A resin which is cured while being foamed is used as the self-curing resin. The resin 2 is foamed in the mold after being injected into the mold while it is still not foamed. The resin 2 has the pressure increased by increasing the fluidity resistance of the resin 2 as it progresses to be cured when the resin 2 intrudes into gaps between the transmission members 4 within the sheath 3, which is caused by an expansion of volume of the resin 2 during foaming whereby the resin 2 is cured under a high pressure.

Abstract: Process for obtaining cellular materials, based on unsaturated polyester in optionally containing reinforcing and/or inert fillers, having a density between 0.2 and 1.0 kg/l by moulding under pressure a liquid foam of said resins, characterized by the fact that the liquid foam based on unsaturated polyester resins containing conventional additives, optionally containing an inert and/or reinforcing charge of mineral or organic fibers having a length which is less than 5 mm, preferably less than 3 mm and more preferably less than 1.5 mm, obtained by mechanical introduction of a gas and/or by means of a chemical and/or physical foaming agent, is firstly introduced into an open half-mould optionally containing a further fiber reinforcement, by casting an amount higher than the free volume of the mould, and subsequently said foam is cross-linked.

Abstract: A method of manufacturing a protective and decorative molding for an automobile, comprising the steps of: adding a foaming agent to a starting resinous material comprising a vinyl chloride polymer or copolymer or a blend thereof; kneading the foaming agent and the starting resinous material; successively forming the kneaded mixture into an elongated rod or sheet blank by means of extruder or calender rolls; shearing the rod or blank into pieces having a predetermined shape; and molding the piece in a mold having high-frequency heating electrodes to apply a high-frequency voltage to the piece so that the foaming agent contained in the piece decomposes and foams to provide a product having a predetermined shape.

Abstract: Novel cardiovascular prosthetic devices or implants having many useful cardiovascular applications comprise a porous surface and a network of interconnected interstitial pores below the surface in fluid flow communication with the surface pores. Tissue forms a smooth thin adherent coating of self-determining thickness on the porous surface making it resistant to the formation of the blood clots normally associated with the presence of foreign bodies in the blood stream. The device has particular utility in heart valves, pacemaker electrodes, blood pumps, blood stream filters, an artificial pancreas, vascular access tubes, small and large bore vascular grafts, blood pump diaphragms and vascular and intracardiac patches.

Abstract: A polyamine mixture formed from formaldehyde, an ortho-alkylaniline, and an ortho,ortho-dialkylaniline. The polyamine mixture is prepared by heating one of the anilines with formaldehyde, mixing the other aniline with an acid catalyst, and slowly adding the former to the latter. The mixtures are useful as chain extenders in polyurethane processes including reaction injection molding. The novel mixtures give unexpected mold gel and set times as compared to corresponding unmixed compounds formed from a single aniline or formed by previous typical condensation reactions. Also, the proportion of polyamines made by the novel mixtures may be varied to give excellent physical characteristics.

Abstract: The invention relates to an earplug, produced with the use of a polysiloxane which is made foamable and cross-linkable by the use of expanding and cross-linking agents. The method for producing such an earplug comprises preshaping the polysiloxane together with the additives, then finally shaping the earplug in the foaming process and then tempering the finally shaped product.

Abstract: An applicator is provided for coating the uncovered end portions or stubs of pipe sections after they have been welded together. A belt is maintained in tension out of contact with the pipe until the pipe stubs are welded together and coating operations are to begin. The belt is then wrapped onto the pipes forming an annular cavity about the welded stubs. Chain reinforcing mesh is also applied to the exterior of the belt for support. An expanding foam which sets into a hard coating is then injected into the cavity. Once the foam hardens and fills the cavity, the belt and reinforcement are unwrapped from the coated joint and moved away from the pipe.

Abstract: A process of reaction injection molding of polyurethanes is disclosed which includes the mixing of one or more of each of polyols, isocyanates, and catalysts, the reaction of the foregoing ingredients, and the molding and curing of the foregoing mixture into the desired configuration, the improvement comprising mixing with the other ingredients a silicone selected from the group consisting ofZ.sub.4-a SiG.sub.a and R.sub.3-d G.sub.d SiO(Y.sub.2-b G.sub.b SiO).sub.n SiG.sub.c X.sub.3-cwherein Z, R, Y, and X are selected from the group consisting of hydrogen, substituted and unsubstituted hydrocarbon radicals, and mixtures thereof; G is a radical of the structure --D(OR").sub.m OH wherein D and R" are selected from the group consisting of substituted and unsubstituted hydrocarbon radicals, and m has a value of 1 to 50; a has a value of 1 to 4; d and c have values of 0 to 3, and b has a value of 0 to 2 wherein d, c, or b has a value of at least 1; and n has a value of 0 to 350.

Abstract: A rotational molding process for manufacturing objects having a foamed plastic substrate adhered to an outer polyolefin coating layer, and having improved adhesion therebetween comprising the combination of steps of: preparing a first outer coating layer of a stabilized polyolefin; forming a second inner layer of an at most slightly stabilized polyolefin contiguous with and on the interior surface of said first outer layer; and thereafter introducing a foamable plastic material onto the interior surface of said second layer and foaming said plastic material thereagainst thereby the foamed plastic is bonded to said second interior surface.

Abstract: A method and apparatus for producing a foamed polymeric sheet having comparatively high density skin layers. Molten polymer containing a foaming agent is extruded from a die into a post-extrusion region defined by the die and a spaced pair of rotating chill rolls which are spaced from the die. The post-extrusion region is maintained at a pressure sufficient to at least inhibit expansion of the foamable molten polymer through the use of cooled sealing elements which occupy a substantial portion of the space between the die and the chill rolls, and are spaced from the chill rolls. The rolls and the sealing elements are cooled so that foamable molten polymer in the space between the sealing elements and the rolls becomes solidified, completing the seal. The chill rolls are maintained at a temperature below the temperature of the molten polymer to aid the skin formation on the surfaces of the polymer. If desired, the polymer can pass directly from the chill rolls into a water bath.

Abstract: A process for manufacturing expanded polystyrene panels includes the following stages:(a) Preparation of pre-expanded panels of polystyrene by extrusion and simultaneous injection of propellent agent into an extruder fitted with an extrusion die of suitable type and in particular fitted with means allowing for good mixing of the molten polymer with the propellent agent and means allowing for uniform cooling to the best value of the temperature of the expandable plastic mass before exit from the die.(b) Conditioning of said panels at room temperature or at whatever temperature higher than room temperature, provided it is such to prevent the panels from undergoing either dimensional variation or deformation due to internal stress or true expansion.

Abstract: A machine for molding sheets of foamed material includes an upright stationary steam chest having opposing perforated external faces, and a pair of movable assemblies abuttable with the opposite faces of the steam chest to define mold cavities therewith. Each cavity forming assembly includes a mold frame extending normal to a face of the steam chest, and a platen positioned within and coupled to the mold frame. Jackscrews move each mold frame into and out of abutment with the steam chest, and also move each platen relative to its respective mold frame toward and away from the steam chest. A method of molding sheets of foamed material is also disclosed wherein heated polystyrene beads are squeezed by the movable platens to a predetermined thickness to provide a board having the desired dimensions and density.

Abstract: The invention provides a novel method for the preparation of a foamed body of a vinyl chloride-based resin composition having a very fine and uniform cellular structure in a continuous process with outstandingly low costs. The method utilizes a binary volatilizable blowing agent composed of (i) a first volatilizable organic compound which is a halogenated or unhalogenated aliphatic hydrocarbon boiling at 90.degree. C. or below and (ii) a second volatilizable organic compound selected from halogenated or unhalogenated aromatic hydrocarbons, ethers, ketones and esters having a specified solubility parameter in consideration of the compatibility with the vinyl chloride-based resin.

Abstract: An apparatus for the molding of seals, packings and the like comprising a curing chamber, the curing chamber being heated by a gaseous medium circulated within, and being selectively, substantially closed to ambient temperatures during the curing process. Provision is made to dispose at least one mold in the curing chamber through a lateral opening and to place the mold under compression during the curing process.

Abstract: Forming polystyrene foam by extruding polystyrene, nucleating agent, physical blowing agent, and water where the physical blowing agent and water are injected into extruder to provide blowing system. The product produced has small cells at junction points between membranes of the foam.