Abstract: The invention relates to a method and an apparatus for the manufacture of high-pressure hose composed of a plastic core and a plurality of layers of helically wound plastic-resisting members formed in particular of wires of high tensile strength which are rewound in a rewinding device from a supply reel onto several working spools, and optionally of an outer cover made of a plastic material. An intermediate layer of plastic yarn is disposed between every two helically wound pressure-resisting layers. After being unwound, the wires necessary for the helically wound pressure-resisting layers are precoiled over a hardened edge in the rewinding device and then wound onto the working spool in the stretched state. In accordance with the preferred embodiment, precoiling is done, not in a stranding machine, during hose production, but one stage earlier, in the rewinding device, where the individual wires are rewound from a supply reel onto so-called working spools.

Abstract: An improved method for producing a reinforced hose. A tubular core is extruded and then heated in a microwave oven to at least partially cure the core. While the core is still hot, a powdered hot-melt adhesive is electrostatically coated onto the core and forms a fusion bond with the core. The coated core is cooled, a reinforcement is applied to the core, an optional outer coating is applied and then the composite is heated to finish curing of the hose and to melt the adhesive to bond the reinforcement to the core.

Abstract: A mixture of substances is fed to an extruder and, after being homogenized and liquefied, is extruded on an electric conductor or as a pipe. To meet electric cable specifications, the insulating material used is a polyolefin, such as polyethylene, cross-linking of which is brought about by the addition of a silane, a free-radical generator, and a silanol condensation catalyst. After extrusion, cross-linking takes place in the presence of moisture. To facilitate penetration of the moisture and accelerate cross-linking, an agent capable of reducing the rate of crystallization of the polymer, such as vinyl acetate, is used as a further additive.

Abstract: A flexible heating element comprises at least two flexible electrical conductors spaced apart by a PTC material, an amorphous highly conductive rubber compatible with the PTC material and adhered to each conductor being interposed between the PTC material and each conductor whereby in use current passes from one conductor to another through the PTC material via the highly conductive rubber. The conductors are spaced sufficiently close to one another to ensure that when energized the PTC material heats substantially uniformly without exhibiting a significant temperature gradient between the conductors and that any abnormal temperature increase increases the temperature of all the PTC material between the conductors in the region of the abnormal temperature increase. The arrangement is such that in use the contact resistance between the conductors and the PTC material is reduced by the amorphous highly conductive rubber interposed therebetween.

Abstract: In the production of a tubular extruded section of thermoplastic material, the actual length of an extruded section at the end of the extrusion operation may be smaller or greater than the length of the extruded section which passed through the discharge orifice of the extrusion head during extrusion. If the wall thickness of the extruded section is varied during extrusion in accordance with a given program, inaccuracies in regard to distribution of the wall thickness over the length of the extruded section can be reduced by detecting the length of the extruded section which passes through the discharge orifice, and controlling the means for producing the programmed variation in wall thickness, in dependence on that discharge length. The same effect can be achieved by controlling the means for producing the programmed variation in wall thickness, in dependence on discharge speed and time.

Abstract: A method of producing a biaxially oriented sheet or film, wherein molten resin is simultaneously, biaxially oriented in a direction of extruding the molten resin and in a direction perpendicular thereto, and an apparatus therefor, are disclosed. In the method of producing a biaxially oriented sheet or film, the molten resin is extruded into a tubular form in the horizontal direction, once cooled, thereafter, in heating the tubular resin prior to the biaxial orientation, the tubular resin is uniformly heated with the heating applied on the vertically lower side and the heating applied on the vertically upper side of the tubular resin being controlled separately of each other so as to prevent the ununiformity of the heating of the tubular resin in the circumferential direction thereof due to the elevation in heat caused by a thermal convection phenomenon, and then, the tubular resin is biaxially oriented.

Abstract: Disclosed is an apparatus and process for the production of multiple-layer film or sheeting having desirable surface characteristics, especially including uniformity of layer thickness and width. The apparatus includes a feedblock which selectively splits the coextruded streams, controls the flow thereof and applies the layers in a manner such that the thickness of the various layers can be more easily and accurately controlled across the width of the sheeting.

Abstract: A method and apparatus for the formation of a continuous web of a tubular thermoplastic film from an extrudate of a thermoplastic polymeric material or resin, wherein the thermoplastic film has a profiled wall contour extending in the direction of the longitudinal axis of the film. The apparatus for forming a profiled tubular thermoplastic film, and the method which is implemented through the intermediary of the apparatus, provides for an annular cooling ring extending about the extrusion die orifice and which incorporates a central aperture through which the extruded plastic material is conveyed while still in a molten or heat-plastified state, and is adapted to direct a uniformly distributed flow of a cooling medium, such as air, against the circumferential surface of the extruded tubular plastic film material.

Abstract: Shaped articles, particularly tubular shaped articles, are formed by a process comprising molding a crosslinkable synthetic plastic material into a first molded shape, crosslinking the plastic material at a temperature in excess of the crystalline melting point of the material, subjecting the crosslinked first shape to a working operation to form a second configuration shape and subjecting specific areas of the second shape to a heat treatment thereby forming a deformation in the specific area. Extruded tubular materials subjected to a stretching operation tend to seek their original shape upon heat treatment thereby making the degree of deformation possible nearly equal to the degree of stretching.

Abstract: An integrated reticulate structure comprising interconnected criss-crossing arrays of continuous or discontinuous filaments. The arrays are located in different layers and are mutually connected by flexible, generally strip-shaped links. Each link is integral with a filament in one array and with a filament in another array.A method of manufacturing an integrated reticulate structure commencing by extruding sheet in form of an adhesively connected assembly of one or more films and one or more arrays of ribs extending from at least one surface of each such film. To enable a formation of thin ribs and of a close spacing of the ribs there is preferably further coextruded a separating component between the ribs.

Abstract: An adjustable die mechanism (10) for extruding a profiled strip of plastic or elastomeric material wherein a plurality of adjacent segments (44) is located upstream and in spaced relation from a final extrusion die assembly (32), having a predetermined profiled opening (38), with this plurality of segments (44) being mounted for individual and independent adjustment thereof, each segment having one end (46) capable of extending into the extrudate flow channel (26). Means for actuating (64) move the segments (44) relative to the profiled opening (38) in a predetermined manner such that moving the segments (44) into the profiled opening (38) modifies the flow of the extrudate material downstream of the segments (44) as the profiled strip emerges from the die assembly (32). The die mechanism includes control means (82) for selectively operating the means for moving the segments so as to produce a strip of material having the desired characteristics.

Abstract: A compound composite structure is a combination of plastics and other materials forming a structure usable in the fabrication of manufactured products or components. A compound composite structure is composed of a thermoplastic resin material bonded to, by mixture with, a composite reinforcing structure. The composite reinforcing structure consists of fibers imbedded in a thermoplastic resin material. The composite reinforcing structure may be formed by passing extruded plastic resin material through a die which imbeds fibers. The compound composite structure may be formed by mounting a preformed composite reinforcing structure in a molding die and by injecting thermoplastic resin material into the molding die.

Abstract: An elongated flat die, for extruding parallel streams of different polymers to form a continuous, striped film, includes a body member which houses a replaceable insert. The insert is formed with grooves on at least two abutting surfaces, which, together with the interior surfaces of the body member, define separate, alternating passages through which the polymers flow. Streams of the different polymers flow together in alternating arrangement and exit the die through a variable lip passage.

Abstract: This invention provides an improvement in a method of cooling molten extruded tube produced by a blown-tube process. The improvement comprises cooling the tube utilizing the heat of evaporation of moisture in steam. The steam is brought into contact with the molten tube after extrusion of the molten tube from an extrusion die, whereby the steam is permitted to expand prior to, during or subsequent to contact with the molten tube. An apparatus is also provided for carrying out the above-described method.

Abstract: A single or multi-layer of films containing at least one oriented, piezoelectric-sensitive (PES) film, sandwiched between resilient conductive liners, is subjected to a high dc field strength while the layer is maintained at an elevated temperature to induce piezoelectric properties in the oriented PES films without the films wrinkling.

Abstract: An extrusion head with an annular extrusion die gap or orifice for fabricating a hollow extrudate of thermoplastic material. The extrusion head has a central die core and outer die casing ring cooperating to define the die gap. The inner boundary of the die gap is formed by a wall of the die core, while the outer boundary of the die gap is formed by a wall of the casing ring. At least one boundary wall of the die gap comprises independently movable sections that move with respect to the other boundary wall to change the width of the die gap.

Abstract: A multi-layer laminate is formed by coextruding plural polymer layers in face-to-face contact with tooth-like interconnections at the layer interface.

Abstract: Tetrafluoroethylene polymer tubes are ram extruded. Desirable quality tubes are obtained by positioning an insert between ram and mandrel to maintain the ram and mandrel concentric.

Abstract: A multilayered thermoplastic sheet suitable for thermoforming into containers, the sheet being simply and expeditiously prepared and provided with consistent and reliable bonds between layers in a single process step by coextruding a layer of a polyolefin having moisture barrier properties and a specific gravity greater than 0.9 with a polyester layer, to provide chemical resistance, microwave heatability, and quick and inexpensive thermoforming for the multilayered sheet.

Abstract: A method of producing an extrudate using a roller die is disclosed in which on-line adjustments are made to size and shape deviations by changing the rotational speed of the extruder screw, the feed rate to the extruder, or the speed of the take-away device and the rotational speed of the roller die. The size and shape dimensions of the extrudate are measured and used to calculate new values for the screw or take-away speed of the feed rate and the roller die speed. A measurement of the extrudate dimensions may also be obtained at the roller die to provide a faster response.