Abstract: A process for producing a boron nitride crucible having a closed end, an open end, an internal surface and an external surface, and wherein at least a portion of the external surface, preferably proximate the open end of the crucible, is coated with a duplex layer comprising a first coating of pyrolytic graphite and a top coat of pyrolytic boron nitride.

Abstract: A method is provided for preparation of a fluoro-polymeric film on a carrier, covering:(a) preparing an aqueous dispersion of polymeric material;(b) dipping a fluoropolymer pre-treated carrier belt through the dispersion so that a coating of the dispersion is formed on the carrier belt;(c) passing the coated carrier belt through a metering zone to remove excess dispersion;(d) drying the metered coated carrier to remove the water from the dispersion; and(e) heating the dried coated carrier to a temperature sufficient to consolidate the dispersion. The carrier belt is formed from a material of low thermal mass having chemical and dimensional stability at the consolidation temperature of the dispersion and a work of adhesion between the carrier belt and the dispersion that does not exceed the yield strength of the consolidated fluoropolymeric film.

Abstract: Metal-ceramic interfaces of enhanced strength are produced by positioning bodies of ceramic oxides and transition element metals or alloys containing such in abutting relationship, and heating in air at a temperature ranging from 500.degree. C. to just below the melting point of the metal of the metal body to join said bodies and then subsequently heat treating said joined bodies in a reducing atmosphere at a temperature in the range of 300.degree. C. to 1200.degree. C. to form intermetallic compound layer at the interface.

Abstract: A method for forming a mask to be placed over at least a portion of an individual's face wherein a plurality of overlapping folds are formed in the sheet of material while the sheet of material is formed into the mask shape, the overlapping fold cooperating to maintain the sheet of material in the formed, predetermined mask shape.

Abstract: A method of molding polysilazane which includes heating a liquid sheet composed of liquid polysilazane alone or containing not more than 30 wt. % of a ceramic powder or a ceramic precursor to form a highly viscous sheet having a viscosity coefficient of 10.sup.4 to 10.sup.6 poise, fitting the highly viscous sheet to a forming mold, and heating to set the sheet. According to the method of the invention, molded bodies are easily obtained which have relatively uniform thickness, and are excellent in transferability, homogeneous and show less defects.

Abstract: A method of manufacturing polymer seals consisting of bonding together a combination of cured pre-polymers to form a single multi-layered seal of varying hardness urethane with at least one pre-polymer being a polyester based pre-polymer and at least one pre-polymer being a polyether-based prepolymer.

Abstract: Mechanically robust star couplers of polymer optical waveguides having low insertion losses and small fluctuations between the individual output fibers are obtained if polymer optical waveguides are arranged in parallel in the middle region of an apparatus and fused with one another under pressure and with the supply of heat. The optical cladding of the polymer optical waveguides has been previously removed. The method is easy and cost-effective. The apparatus is composed of a lower part with a channel recessed therein and an upper part with a male die located therein, which male die corresponds in its shape to the shape of the channel.

Abstract: A process for producing a polycarbonate molded article having a low dust level from a polycarbonate resin in the form of a powder or pellets by injection molding using an injection molding machine. The injection molding machine includes a cylinder whose inner circumferential wall is made of a corrosion- and abrasion-resistant alloy from alloy components (1), (2), or (3) given below and a screw part made of a steel having a metal coating formed of hard chromium plating or hard nickel plating or formed of titanium carbide or tungsten carbide, or is made of SUS420, SUS440, Hastelloy C, or a steel of alloy component (4) given below:Alloy components (1):C: 0.5-1.5 wt%Si: 1.0-2.0 wt%B: 0.5-2.5 wt%Ni: 10.0-20.0 wt%Cr: 20.0-30.0 wt%W: 10.0-20.0 wt%Cu: 0.5-2.0 wt%Remainder: Co and unavoidable impurities,Alloy components (2):Ni: 0.0-2.0 wt%Cr: 5.0-15.0 wt%Fe: 0.0-1.0 wt%Mn: 0.1-2.0 wt%Si: 0.2-4.0 wt%B: 2.0-4.0 wt%Remainder: Co and unavoidable impurities,Alloy components (3):Cr: 5.0-10.0 wt%Co: 5.0-40.0 wt%Fe: 0.0-10.

Abstract: A method for setting an ophthalmic lens in a pair of goggles having a flat front transparent lamina for permitting vision and also having a shielding rim surrounding the lamina extending towards the face of the wearer for the abutment thereon is characterized by a lens secured inside the shielding rim adjacent the lamina. The ophthalmic lens has a flat plane adjacent the lamina separated therefrom by an air gap. A first silcone-base caulking is deposited between the periphery of the lens and the shielding rim up to a level substantially corresponding to the thickness of the air gap. This first caulking has a viscosity sufficiently sag-proof to maintain the caulking at the periphery of the gap during its hardening. A second caulking having a lower viscosity is deposited on the top of the first caulking up to a level corresponding to the top of the lens. The caulking is selected to be free of toxic and corrosive gas. The lens has a peripheral groove to improve the adherence of the second caulking.

Abstract: The invention relates to stretching of a continuous web of a thermoplastic sheet, such as polyvinyl butyral sheet, having straight longitudinal edges into an arcuate form to use it as an interlayer of curved and laminated windshields of vehicles. Usually the web has a colored band to serve as a glare shield band along its one longitudinal edge. First the web travels vertically downward and is heated from its both sides by a vertical heater to produce a gradient of temperature across the width of the web such that the temperature at the web edge remote from the colored band becomes higher than the temperature at the opposite edge. Under longitudinal tension the heated web is passed around a first heated tapered roll and then around a second heated tapered roll having a higher temperature. Over these tapered rolls the web edge remote from the colored band is located relatively near the large diameter end of each tapered roll.

Abstract: A process to fabricate lightweigth ceramic mirrors, and in particular, silicon/silicon carbide mirrors, involves three chemical vapor deposition steps: one to produce the mirror faceplate, the second to form the lightweight backstructure which is deposited integral to the faceplate, and the third and final step which results in the deposition of a layer of optical grade material, for example, silicon, onto the front surface of the faceplate. The mirror figure and finish are fabricated into this latter material.

Abstract: A technique for forming a mold to replicate large numbers of plastic articles, such as by injection or blow molding, wherein the mold contains a hologram or other microstructure for transfer to an outside surface of the molded article. The mold is made by electrodepositing a metal on a model of the article to be molded. Before this deposition, the hologram or other microstructure is formed on a surface area of the model by any one of several techniques. The result is a unitary mold piece in the shape of the article and having the hologram or other microstructure integrally formed on its inside surface.

Abstract: Molded carpet for use in motor vehicles is made by a method which allows the molding of carpet having deep well areas. The method comprises the steps of heating a plastic backed carpet blank to a degree to make its backing pliable and thereafter molding the heated carpet in a set of specially constructed molds. The molds generally have the shape of the floor area to be covered. However, they are arch-shaped from edge to edge at those portions of the mold where draws are needed to accommodate specially contoured well areas of the motor vehicle's floor area.

Abstract: The invention relates to a method of spin casting lenses having optical surfaces which may be spherical, aspherical or toric in shape. The method provides a concave optical mold having a spherical, aspherical or toric optical surface. A convex optical mold having a spherical, aspherical or toric surface is also privided. A selected liquid lens monomer with a selected catalyst is placed in the concave lens mold. The convex optical mold is positioned in the concave mold displacing the liquid lens monomer. The optical axis of the concave and convex molds are aligned and the two molds rotated about their concurrent optical axis. The liquid monomer is allowed to polymerize forming a solid polymer lens. The finished lens is then removed from the molds.

Abstract: In the injection molding process of ceramics, an injection mold having an area of the gate of at least 20% of the maximum cross-sectional area of the cavity viewed from the gate side is employed. The gate preferably has a shape substantially similar to a projection of the cavity viewed from the gate side. Further, the temperature of the mold is preferred to be controlled to have a temperature gradient in such a manner that the distribution of temperature of the molded body in the vicinity of the mold is brought into the range of .+-.0.5.degree. C. about a setting temperature, at the time pressurization of the molded body in the mold has just been completed. According to the process of the invention, the molding material injected and passed through the gate is controlled to flow smoothly along the shape of the cavity, uniformly purging the air so that homogeneous molded bodies free from defects, such as pores, weld-marks, or the like, can be obtained.

Abstract: A method of forming an optical fiber defining an axis, the fiber having a dipolar dopant wherein a substantial number of the dipoles of the dopant are oriented in essentially the same direction along the axis of the fiber; the method comprising the steps of providing a vessel having a spinneret, establishing a substantially constant electric (or magnetic) field adjacent to, axially aligned with and downstream of the spinneret, forming a prefiber homogenous liquid mixture of at least one dipolar dopant and at least one polymer in the vessel, extruding the prefiber through the spinneret, drawing the extrudate through the electric (or magnetic) field to generally align the dipoles in the same direction and simultaneously elongating the extrudate while it is still in the fluid state by drawing the extrudate.

Abstract: A method of producing a nonlinear optical film from a lyotropic liquid crystalline polymer by diluting the polymer with a dopant to form a concentrated mixture. The concentrated mixture is filtered in a high pressure filtration cell and vacuum degassed. Thin film are formed on plates and are coagulated in water. The thin films are supported on a microporous membrane support and then air dried.

Abstract: This invention concerns the production of oriented polymeric films in which a layer of an ambient temperature curable silicone resin composition is formed on a layer of a polymeric film which is thereafter stretched at an elevated temperature to effect orientation of the film. The silicone resin composition includes a volatile inhibitor for inhibiting curing of the composition while stretching is effected. Suitable inhibitors include alkanols when the silicone resin has hydroxyl functionality. Films so produced can be used as release films.

Abstract: A method of making an improved YBa.sub.2 Cu.sub.3 O.sub.6+x ceramic superconductor. The method includes the steps of: adding aluminum powder to YBa.sub.2 Cu.sub.3 O.sub.6+x powder to form a powder mixture, pressing the powder mixture, and rolling the pressed mixture into a thin ceramic superconductor. The addition of aluminum results in improved superconducting transition temperature, ductility and formability.

Abstract: A hollow cylindrical flux source (HCFS) is formed into a toroidal shape. A hollow toroidal of magnetically neutral material is mounted in the central cavity of the toroidal flux source. The hollow toroidal has a central coaxial toroidal cavity of given cross-section (e.g., rectangular). The toroid flux source and the hollow toroid are each equatorially split into two halves. When the two halves are brought into juxtaposition and a suspension of magnetic material is deposited in the coaxial toroidal cavity a permanent magnet toroidal ring will be fabricated.