Abstract: A method for packaging semiconductor devices in resin uses a mold having a pot and cavities, a vacuum pump for drawing off the air contained in the pot and the gases emitted from a resin tablet placed in the pot, and a pressing piston for pressing the resin tablet to feed the resin to the cavities. The pot has a volume which is greater than the maximum volume to which the heated resin tablet expands in a vacuum. The method includes the steps of placing the resin tablet in the pot, heating the resin under an applied vacuum until it expands to a sufficient extent to draw away gas trapped in the heated resin tablet, pressing the heated resin to the cavities to surround semiconductor devices placed therein, and curing the resin.

Abstract: A mold or die having two parts with a cavity and an interface between them and a feed opening in one of the mold parts cooperates with a charge feed for raw changes and any evacuation device providing a low pressure.

Abstract: Sailboards having a tucked rail are made from a flexible, resilient mold so that the seam of the board is along its bottom edge instead of at its point of greatest breadth. A flexible mold part having the contour of the sailboard to be produced has an opening smaller than the greatest breadth of the board. The mold is first flexed so that its opening is sufficiently wide to receive the blank that forms the body of the sailboard. Secondly, the blank is inserted into the flexed mold, and thirdly, the mold is released and its resiliency returns it to its original shape. A conventional rigid mold part closes the open end, and a vacuum is applied to form the final product. The flexible mold part is flexed a second time to remove the product.

Abstract: For moulding self-stiffened panels (A) from a composite material with a thermosetting matrix, use is made of a tool having a block (10), a sealing bag (12), whose peripheral edge is connected to the block by a sealing bead (14), and solid, non-deformable calibration parts (22). Panel (A) is placed in a tight volume (16) defined between the block and the bag, while the parts (22) are placed outside said volume, above the bag and between the panel stiffeners (C). The calibration parts (22) are connected by a rigid structure (24). Thus, when the volume (16) is placed under a vacuum and when the tool is placed in an oven or autoclave, a uniform pressure is applied to the panel by the bag (12) and the parts (22) ensuring the maintenance of the geometry of the stiffeners.

Abstract: A method for producing a sleeve having a closed end by extruding a forming material from a mouthpiece. A core member is arranged in position in the mouthpiece and has a piston member detachably provided in a tip end of the core member. The piston member has an air communication aperture. On the other hand, an outer die is arranged in the mouthpiece for forming an outer configuration of the closed end. As a result, an annular space is formed by the mouthpiece, core member and outer die. The forming material is then supplied into the annular space and extruded to form the closed end of the sleeve. After the outer die has been removed from the mouthpiece, the piston member is caused to slide relative to the mouthpiece and at the same time the air is blown into an inside of the closed end through the air communication aperture of the piston, while the forming material is further supplied and extruded from the mouthpiece to form the closed end sleeve.

Abstract: A method and apparatus for forming a continuous extrudate of a heated soft thermoplastic material into a continuous sheet of a cooled rigid thermoplastic material having a plurality of recesses formed in one surface thereof and a plurality of projections formed on the other surface thereof by feeding successive portions of a heated soft extruded thermoplastic material onto successive portions of a forming cylinder having a generally cylindrical outer peripheral surface having a plurality of recesses formed therein and applying a vacuum through the recesses to draw areas of successive portions opposite to the recesses into conformation with the recesses and cooling the thermoplastic material by moving a cooling fluid over the inner peripheral surface of the forming cylinder and removing the successive portions to form a continuous sheet of a rigid thermoplastic material having a plurality of recesses formed in one surface thereof and a plurality of projections formed on the other surface thereof.

Abstract: A method for molding powders comprises the steps of forming a mold support having at least an opening and a cavity, forming a film of latex on inner surfaces of the mold support by pouring the latex from the opening into the cavity of the mold support and discharging a substantial portion of the latex poured into the cavity, forming a thin-wall resilient mold inside the mold support by drying the film of latex formed, charging powders as materials for a compact from the opening into the thin-wall resilient mold, exhausting air out of the thin-wall resilient mold filled up with the powders through the opening and sealing the opening of the thin-wall resilient mold, separating the thin-wall resilient mold filled up with the powders from the mold support, and subjecting the thin-wall resilient mold to a cold isostatic press method treatment.

Abstract: Graphite blocks are produced by a process wherein one or plural polymer films having a thickness of from 1 to 400 .mu.m and selected from aromatic polyimides, aromatic polyamides and polyoxadiazoles are heat treated to obtain carbonaceous films. A plurality of the carbonaceous films are hot pressure under certain conditions to obtain thick graphite blocks. The blocks have a remarkably improved rocking characteristic and are useful as radiation optical elements such as X-ray or neutron ray monochromators or filters. The blocks may be curved to obtain bent-type graphite articles.

Abstract: A method of molding using breather layers particularly adapted for use for removing fluids from articles during molding, that retain fluid paths at high pressures. Polymer containing articles are molded using a breather layer that is substantially capable of maintaining a fluid path under pressures up to about 20.7 MPa. The method includes transferring pressure via a gas impervious layer to the article. The breather layer is disposed between the article and the gas impervious layer and provides a fluid path for removing fluids from the article. An exemplary breather layer includes at least two flexible layers of beads that are dimensionally stable at pressures up to about 20.7 MPa. These breather layers facilitate high pressure molding by maintaining a sufficient fluid path size so that volatiles can be easily vented. This results in stronger, denser composite articles.

Abstract: A method of making an inorganic slurry, forming the inorganic slurry into a useful article and method of removing the solvent medium from the formed article. The slurry contains an inorganic powder, water, dispersant, thermally gelable polymeric binder and optionally a plasticizer. The method comprises admixing the inorganic powder, water and dispersant to form a blend. The blend is a ball milled, heated, and admixed with a thermally gelable polymeric binder to form a slurry mixture, then the mixture is cooled. The slurry mixture can be extruded to form useful articles, such as metal or ceramic tapes. Additionally, the invention is also a method of final shaping and removing solvents from the formed article. A heated calendar roll stack assembly is used to rapidly remove the solvent from the article. When sintered, the resulting article is very dense and exhibits substantially no voids.

Abstract: A method of filling an annular space between inner and outer coaxially arranged pipes while providing the option of maintaining fluid flow through the inner pipe includes optionally establishing fluid flow through the inner pipe; installing first and second seals in the annular space between the two spaced apart pipes at first and second ends of the pipes and inserting one end of a vacuum tube into the annular space through the first seal at the high point in the first seal. A grout tube is inserted into the annular space through the second seal at the high point of the second seal. A vacuum is applied to the second end of the vacuum tube and a grout mixture is applied to an opposite end of the grout tube. A sufficient vacuum is maintained within the annular space for such a time period to draw the grout mixture from the second end to the first end of the pipes to completely fill the annular space.

Abstract: A process and system for vacuum impregnation of a fiber reinforcement, such as carbon cloth, with a resin to produce a resin-fiber composite. Liquid resin enters in arrangement or system comprising a fiber reinforcement layer on a tool or mold and is directed via a system of flow paths to impregnate the fiber reinforcement layer uniformly across the width thereof and along the length of the fiber reinforcement layer. According to one embodiment, a fiber reinforcement layer, e.g., carbon cloth, is placed on a tool. A porous paring film is applied over the fiber reinforcement layer and a bleeder layer, e.g., fiberglass, is applied over the parting film. A non-pourous film is placed over the bleeder layer, a breather cloth, e.g., fiberglass, is then applied over the non-porous film, and a vacuum bag is placed over the entire assembly and sealed to the mold surface. Liquid resin is fed to the assembly within the vacuum bag. Resin spreader means, e.g.

Abstract: A meltblowing collector screen includes a vacuum pump and internal partitions for achieving substantially uniform air flow through the length of the screen thereby producing a web of uniform thickness.

Abstract: A method of consolidating a fiber reinforced thermoplastic poly(arylene sulfide) composite by vacuum bagging. A fiber reinforced thermoplastic is placed between stainless steel sheets and then placed in a vacuum bag. A vacuum is applied to the bag and heat and pressure are applied to the layup to form a composite. A plurality of fiber reinforced sheets may be consolidated between a plurality of stainless steel sheets.

Abstract: A method is provided of manufacturing a skinless, nylon microporous hollow fiber membrane. The method comprises the steps of providing a nylon polymer dope solution and a quench liquid capable of solidifying and forming micropores in an extruded nylon polymer dope solution to produce a skinless, microporous nylon membrane. The quench liquid is placed into a vessel and a tube is provided which has a top and a bottom outlet. The bottom outlet of the tube is partially submerged in the quench liquid, the tube vertically extending therefrom. A spinneret is provided which has an outlet adjacent the top of the tube. The chemical quench liquid is raised in the tube until it is in substantial contact with the spinneret outlet. The nylon polymer dope solution is extruded in the form of a hollow fiber through the spinneret outlet directly into the quench liquid.

Abstract: A mandrel assembly supports an umbilical cord during the shaping and curing of the cord for use as a vascular graft. The mandrel assembly has a pair of mandrel members adapted to be releasably connected in end-to-end relation. Adjacent end sections of the mandrel members have reduced cross sectional shapes to provide the graft with a throat to restrict the flow of blood through the vascular graft. Each mandrel member has a low friction outer surface to facilitate the insertion and withdrawal of the mandrel member from the lumen of the umbilical cord. In one embodiment, the adjacent ends and neck portions of the mandrel members have small holes. A vacuum pump draws air from within the mandrel members to withdraw moisture from the tissue of the umbilical cord and hold the umbilical cord in conforming relationship with the joined mandrel members during the forming and curing of the umbilical cord.

Abstract: A preformed yarn useful in forming fiber-reinforced carbon composite articles is disclosed which includes a core of a multiplicity of inorganic reinforcing fibers, a mixed powder provided in the interstices between the fibers and including a finely divided carbonaceous binder pitch and a finely divided coke, and a flexible sleeve formed of a thermoplastic resin and surrounding the core.

Abstract: Moldings (41) of fibre/resin matrix composite material are vacuum bag molded "net-to-size" by providing periphery elements (20-22) on the molding face (11) of the tooling (10) and allowing them to slide on the molding face during curing of the molding. Buttstrap edges (FIG. 3) can be provided in this way, on the molding, as an integral part of the molding process.

Abstract: Method for fusion joining first and second axially abutted thermo-plastic piping system component connection ends that are in axial and circumferential alignment. The joining apparatus includes apparatus for enabling the heating of a melt region in the proximity of the interface of the first and second piping system component connection ends at least to the material softening point of the thermo-plastic material of the melt region, and further includes vacuummetric apparatus for vacuummetrically inducing outward translation of the melted material of the melt region. The method includes the steps of (a) heating a melt region in the proximity of the interface of the first and second piping system component connection ends at least to the material softening point of the thermo-plastic material of the melt region, and (b) vacuummetrically inducing outward translation of the melted material of the melt region.

Abstract: A method of making a sanitaryware article with a light transmitting panel. A sheet of light-transmitting plastic is formed into the shape of a article of sanitaryware which has a sump. A mask is applied to a portion of the plastic sheet and the remaining portions are covered with a coating which makes the areas opaque. The mask is removed and a rigid panel of a light transmitting plastic is bonded to the light transmitting area of the shell.

Abstract: A method of forming a hole in a plastic pipe feeds a plastic layer for the plastic pipe from a nozzle about a mandrel into chill moulds being displaced along an elongated mould cavity about the mandrel formed by the chill moulds. All of the plastic layer is pressed into the chill moulds with a pressure medium between the mandrel and all of an inner surface of the plastic layer for forming the plastic pipe therefrom. Only portions of the plastic layer of the plastic pipe are then subjected to a local pressure difference exceeding the breaking limit of the plastic layer between the inner surface and an opposite, outer surface of the plastic layer at least in part from a flowing medium for forming a hole in the plastic layer of the plastic pipe, the flowing medium being one of a gas and a liquid and flowing from the mandrel at a pressure higher than that of the pressure medium pressing the plastic layer of the plastic pipe.

Abstract: A method of making tubular composite structures that simplifies vacuum bag sealing. The method comprises disposing a prepreg structure within a tool that has at least one hole. The prepreg is disposed adjacent a mandrel. The mandrel comprises an inner bag containing a solid filler core that comprises about 75% to about 95% of the volume of the inner bag. The hole is enclosed with a vacuum bag thereby forming a void space between said vacuum bag and said prepreg. The void space is evacuated. The vacuum bag applies a predetermined pressure to the inner bag thus causing the inner bag to apply a substantially uniform predetermined pressure to the surface of the prepreg. The prepreg is exposed to heat.

Abstract: A process for the production of a molding from at least one preform, in which process the preform, which has been heated to 330.degree. to 400.degree. C., is pressed by means of a pressure difference which increases slowly during the shaping into or onto a rigid mold heated to about the same temperature, and is then cooled while the pressure difference is maintained and is released from the mold. During the shaping and cooling, the edges of the preform are secured in their original position. The process makes it possible to produce moldings which have a thin wall thickness and a good surface and which exhibit a residual shrinkage which is sufficiently small for most applications.

Abstract: A method of molding oriented structural yarn/polymer matrix composite structural articles in which a preform of oriented yarn layers saturated with a resin is placed in a shape-defining mold, which is put in an enclosure, and subjected to heat and pressure to cure the resin, after which a cooling medium may be introduced. To enable the use of lightweight multi-part molds, and a mixture of pressure is distributed evenly, an internal liner is collapsed about the mold prior to curing. The process is extremely productive, and allows for accuracy and reproducibility through the use of real time temperature monitoring and closed loop feedback control.

Abstract: Methods are disclosed for forming silicone rubber vacuum bag assemblies which can be used repeatedly to debulk and autoclave composite layups. These bags can be formed of a single layup of uncured silicone rubber over a tool of a simple shape or as a layup of uncured silicone rubber over the totality of the tool and a prepreg consisting of a fiber in uncured silicone rubber laid up over areas which do not include male and female radii on the tool. Additionally, a further bag can be constructed by removing those portions of a simple bag which overlay recesses and female radii followed by curing of the silicone rubber and filling of the recesses within uncured silicone rubber followed by a second cure period. Each of the vacuum bag assemblies of the invention is postcured preferredly removed from its defining tool so as to stabilize and fully shrink the silicone rubber. The vacuum bag assemblies are mounted in a silicone rubber membrane which is preferably then supported in a frame.

Abstract: A quench bath, for quenching and solidifying an extruded hollow porous fiber of a liquid polymer solution in a chemical quenching solution, includes a shallow quench bath of a length for the generally horizontal part of the extruded fiber travel in the bath. A vertical extension tube with its lower end beneath the surface of the bath liquid holds a spinneret through which the fiber is extruded. The spinneret is sealed in the tube above the height of the liquid in the shallow bath. A vacuum drawn in the tube raises the liquid up to the spinneret. Also, the vacuum may be drawn by disposing the spinneret in a sealing piston which is raised through the tube to draw the vaccum in the tube behind the piston.

Abstract: The process serves essentially for the thermal bonding of lightweight nonwovens. For this purpose, the nonwoven is heated up by means of air penetration on a sieve drum of a flow dryer to a high percentage of the bonding temperature, and immediately thereafter is embossed with internally heated rolls in the squeeze roll nip of a calender. The apparatus provided for conducting the process consists of a sieve drum device wherein the embossing calender is arranged.

Abstract: Producing a concrete object by first pouring an uncured mixture into a mold and then removing undesired uncured concrete using a suctioning apparatus having a liquid supply and a suction nozzle attached to a suction channel. The concrete mixture is loosened and diluted by liquid supplied through the liquid supply. This liquid and loosened diluted concrete are suctioned through the suction nozzle and the suction channel into a tank.

Abstract: A method for injection molding a material involving bringing the interior of a tightly sealed injection mold under a high vacuum, then injecting the material into the interior of the injection mold at an ultrahigh speed in the vicinity of a speed at which adiabatic change is exerted on the material in accordance with a predetermined pattern of internal pressure so as to fill the interior of the injection mold with the material, and molding the material under low pressure. An injection molding apparatus used for carrying out the aforementioned method is capable of bringing the interior of the injection mold to a high vacuum.

Abstract: A process is disclosed for the continuous manufacture of a perforated plastic film, where the plastic film is extruded directly from the extrusion unit either onto one roller of a pair of rollers or directly into the gap between a pair of rollers (a perforating/texturing roller and a back-up roller). The hot plastic film is perforated on a roller under the influence of a vacuum and shock cooling by the flow of cold air and the coolness of the back-up roller is carried out during the perforating step, and immediately thereafter. The film is preferably textured at the same time that it is perforated, the immediate cooling setting the texture in the film.

Abstract: A mirror--typically of the spherical or aspherical variety--is replicated on a large scale (in the order of 2'.times.4') to an optical accuracy in the range of less than one arc minute. An optical master is created by heat shrinking and holding an acrylic sheet to a steel substrate of the same shape as desired mirror in the constant presence of a vacuum at the steel-acrylic interface. The acrylic is optically polished to complete the master. The master is then appropriately dammed to the mirror dimension and poured with subsequently cured epoxy so that the epoxy forms the optical surface of the replicated mirror. A backing master--created by substantially the same process as the optical master--allows fabrication of a backing, composed of a series of adhesive layers typically sandwiching a core material such as commercial honeycomb therebetween, to be made with a curvature substantially similar to the curvature of the replicated optical surface.

Abstract: An apparatus for manufacturing an embossed article of synthetic resin comprising heating a synthetic resin sheet to a softening temperature; overlaying the heated synthetic resin sheet on an embossing die made by an electro-chemical molding process and having an embossing surface with an embossing pattern thereon and a multitude of fine vacuum pores distributed uniformly over the entire embossing surface; and forcing the synthetic resin sheet against the embossing surface by applying suction through the fine vacuum pores to imprint the embossing pattern onto the synthetic resin sheet.

Abstract: A carbonizable body is formed by infusing a plurality of preoxidized, preferably stabilized by known processing to have about 9 to 14 weight percent oxygen, polyacrylonitrile fibers in a polar liquid plasticizer, preferably water, capable of extracting a tarry leachate from the fibers. The infusion of the fibers in the plasticizer is continued for a sufficient time for a substantial amount of leachate to form on the surface of the fibers, and are then consolidated or diffusion-bonded to one another or other fibers, as by orienting the treated fibers in a mold and subjecting them to isostatic pressing at relatively low temperatures and pressure. Further processing of the consolidated fibers with appropriate heat treatment in an inert atmosphere will produce a carbonized bulk product with higher values of Young's modulus for the carbonized material than have been previously achieved at such carbonization temperatures.

Abstract: During blow molding of curved plastic hollow bodies, the parison is first extruded as a whole in a substantially straight line and vertically from top to bottom. The parison is then severed from the extrusion die and the severed parison precurved. Finally, the precurved parison is inserted as a whole into the blow mold and blown. An apparatus for carrying out this method comprises releasable support means for accommodating and holding the parison, curving means for preliminary curving of the parison, tilting means for tilting the support means into the horizontal position and a blow mold, the precurved parison being placed as a whole in one mold half of this blow mold.

Abstract: A method for molding powders which comprises introducing a thin-wall resilient mold inside a ventilative mold support, reducing the outside pressure of the ventilative mold support to less than the atmospheric pressure (760 Torr), putting a thin-wall resilient mold exactly close to the inside wall of the ventilative mold support, supplying powder material into the thin-wall resilient mold, exhausting air existing in the voids formed in the powder material, and taking the ventilative mold support apart to apply cold isostatic press treatment to the thin-wall resilient mold. The shape of the thin-wall resilient mold is similar to the shape of the ventilative mold support.

Abstract: An end closure for a shirred casing stick is formed from casing inturned into the bore of the stick. A vacuum assist is used to prepleat the casing within the bore prior to compaction. The resulting end closure is a generally cylindrical plug composed of accordion-type pleats and having an end portion which has a substantially uniform density about the longitudinal axis of the plug and a second portion which has an asymmetrical density. The second portion has two longitudinally extending sections; one having its pleats formed of a single ply of casing and a diametrically opposite section having its pleats formed of three plies of casing, thereby providing the asymmetric density.

Abstract: A waterbed mattress has a baffle structure that comprises a horizontally extending pad of buoyant material with a plurality of chambers depending therefrom. The chambers can be hemi-spheroidal. The chamber walls having water metering holes therethrough.

Abstract: The tubular body is laid in a horizontal position on a tapered suction drum and pivoted thereby into a vertical axis which is in coaxial relationship with the axis of a mandrel with a punch. The tubular body is then pushed from the surface of the suction drum on to the mandrel by a thrust member. The mandrel and/or the die is mounted displaceably in a vertical direction, which permits particularly stable and precise guidance. A plurality of dies with mandrels and punches associated therewith is disposed on a rotary member. In the course of a revolution of the rotary member, the tubular body on the mandrel is connected to a squeeze moulding in the die.

Abstract: A laminate consisting of a number of air-permeable sheets of a material is placed on the supporting surface of a table, and a major portion of the periphery of the laminate, inclusive of a lower surface thereof, is covered with a sheet impermeable to air. A suction pipe is arranged on the supporting surface along at least one side surface of the laminate and has a suction port faced toward the one side surface. A periheral portion of the suction port is covered with the air-impermeable sheet, and the laminate is compressed in the direction of its thickness by evacuating air from within a space defined by the air-impermeable sheet by vacuum producing means connected to the suction pipe. The air-impermeable sheet and laminate can be moved together with the suction pipe in parallel relation to the supporting surface, and they can be stopped at a desired position, during the evacuation process.

Abstract: A vacuum mold for vacuum-forming a plastic sheet heated to a high temperature to transfer grain patterns onto the surface of the plastic sheet, the mold comprising an electrocast shell formed, by an electroforming step, with a casting surface having the grain patterns thereon and a multitude of fine vacuum holes uniformly distributed at the casting surface. A back-up body is mounted at the rear surface of the electrocast shell and is provided with vent holes communicating with the vacuum holes in the shell.

Abstract: A sewn polyolefin in fabric bag which uses the molded shapes of the polyolefin material to form a shaped enclosure. Enclosure means and a fabric hinge are sewn directly to the polyolefin enclosure means to form the completed bag. The bags formed in this manner have many of the advantages of both soft and hard shelled bags. The polyolefin material is capable of providing a predetermined shape but has a soft exterior surface and is deformable. Sewing can be done using conventional sewing techniques. Polyolefin materials have not previously been usable in this manner because of their inability to bond or weld in reliable manner to other materials.

Abstract: A method of forming bottomed cylindrical bodies, which can be used conveniently as preforms for the production of containers by stretch blow-molding, etc., from a cylindrical body of thermoplastic resin. The method includes a softening step of heat-softening an axially intermediate part of the cylindrical body, a necking step of necking the axially intermediate part of the cylindrical body radially inwardly, said necking step being carried out subsequently to, or simultaneously with, the softening step, a cutting step of cutting the axially intermediate part of the cylindrical body necked radially inwardly in the necking step, thereby to divide the cylindrical body into two members, and a fusing step of heat-melting the cut end portion of each of the two members and fusing the cut end portion.

Abstract: A method of high-speed spinning polyamidic fiber, comprising the steps of extruding the polymer in the molten state, cooling the filaments by blowing, and finishing, which is performed in two stages, one upstream and the other downstream of the interlacing device.The latter device includes a containing enclosure wherein the interlacing nozzle and at least two pairs of yarn thread guides are accommodated.Fibers obtained with the method have 5 to 29 knots per meter.

Abstract: A process of making a full life size artificial rock formation of photocopy exactness from a natural rock formation surface is disclosed herein. A plurality of coats of latex is applied over the natural rock surface and allowed to dry thus forming a mask having all the natural cracks and crevices of the natural rock surface. This mask or liner is held in a fiberglass mold and a vacuum is applied to the inner surface of said liner causing all the cracks and crevices to open up. Cement is applied to the outer surface of the liner filling all the cracks and crevices. When the liner is removed the artificial surface resembles the natural rock surface in photocopy exactness.

Abstract: A process of manufacturing a ski, particularly a laminated ski, which is composed of a plurality of components, and a ski manufactured by that process. In the process, the components of the ski are placed into a mold, which is adapted to be evacuated, and the mold is subsequently evacuated. A liquid binder, such as a liquid resin, is supplied to the mold during or after its evacuation. Air is sucked from the mold at one end of the longitudinal extent of the ski. The liquid binder is supplied to the mold at the other end of the longitudinal extent of the ski. In the finished ski a strip of solidified binder extends in at least one vertical or horizontal longitudinal plane of the ski, preferably in a central longitudinal plane of the ski, over at least part of the length and preferably over at least one half of the length of the ski.

Abstract: A method for seating a gasket in a plastic pipe bell is disclosed which includes providing a peripheral groove in a belling mandrel and seating a specially designed hard plastic ring in the groove. The hard plastic ring is molded to provide exterior ramps for forming an annular pocket in the pipe bell and is inwardly configured to provide a secure seating surface to receive and retain a resilient gasket thereon. The mandrel is urged into a preheated end of the pipe and vacuum forces are employed to pull the end of the pipe about the periphery of the mandrel and tightly against the exterior ramps of the hard plastic ring for forming the bell shape. Upon sufficient cooling of the pipe end, the mandrel is withdrawn and the plastic ring remains encapsulated within the bell shape. Upon removal of the mandrel, a resilient gasket is then seated within the bell in intimate overall contact with the seating surface of the plastic ring.

Abstract: A method of producing unitary hollow structures, for example radomes, comprised of fiber reinforced plastic with a large percentage of the fibers being randomly oriented in directions essentially parallel to the wall surfaces of the structures and with at least one surface having grooves to reduce microwave reflection is presented. The structures are produced by packing a layer of fiber filled polymeric material in powder form around a mandrel which may have a pattern of grooves of ridges in its outer surface. The mandrel and packed powder are subjected to isostatic pressing to properly orient the fibers and achieve a density increase and powder cohesion. The pressed structure is sintered and the outer surface subesquently machined to a finished contour.

Abstract: A radome combines low dielectric constant and dissipation factor at microwave frequencies with mechanical strength and rigidity as well as resistance to ablation and rain erosion at hypersonic velocities in the range of Mach 4 to 6. Continuous filament glass fabric and/or strand is saturated with PTFE dispersion. Layers are applied to a mandrel and cold isostatically pressed. The pressed layer may be machined between applications and subsequent pressings. After all layers are applied and pressed, optionally including an outer ablation resistant random fiber reinforced PTFE composite, the densified structure is heat cycled above the crystalline melt point of the polymer to maximize mechanical properties.

Abstract: A radome being a unitary structure comprised of a fiber reinforced plastic is produced with a large percentage of the fibers being randomly oriented in a plane parallel to the inner surface of the radome. The radome is produced by packing a layer of fiber filled powder around a mandrel having its outer contour resemble the inner contour of the radome. The mandrel and packed powder are then subjected to isostatic pressing to properly orient the fibers. The radome is finished by sintering the powder and removing the finished form from the mandrel.

Abstract: A method of compression molding powders of metals, ceramics and the like. A thin rubber bag is adhered to the inside of a cavity formed within a permeable mold support so as to define a mold therein and the bag is packed with a raw material powder. The powder in the bag is evacuated to a degree of vacuum to compactly compress it and the rubber bag is sealed. In this condition, the compressed powder is removed from the support and compression molded to a higher degree of denseness by the CIP process. The inflation adhesion of the rubber bag to the inside of the support cavity is effected by reducing the pressure outside the permeable support.