Abstract: A cube corner article and method of manufacturing the article from a series of unitary substrates. A plurality of pins are assembled to form a mold having an array of cube corner elements on a surface. Then, a replica of the cube corner element array is produced in a substrate suitable for forming retroreflective surfaces. Portions of the replica substrate material are removed. The removal of these portions forms at least one cavity bounded by side walls in the replica at a depth at least that of the cube cube corner elements. The replica is replicated to produce an additional directly machinable substrate suitable for forming retroreflective surfaces having at least one raised section having sidewalls at a height at least that of the cube corner elements. At least one raised section is directly machined to form an array of cube corner elements.

Abstract: A metallic composite solid, containing alloys and/or intermetallics, is formed by compacting at moderate pressure a mixture of powder particles, foils or sheets at a temperature close to room temperature, well below the melting temperature of the constituent components and without the addition of low melting metals such as mercury, indium or gallium acting as a sintering agent. This low temperature consolidation of the powder mixture is enhanced by having the surface oxide of the powder particles removed, prior to consolidation, and/or by coating the particles with an oxide-replacing metal such as silver or gold. The coating process may be replacement reactions, autocatalytic reduction or electrolytic reduction. The composite formation is assisted by the addition of a liquid acid such as fluoroboric acid, sulfuric acid, fluoric acid, adipic acid, ascorbic acid, or nitric acid.

Abstract: A dental restoration part is produced from a ceramic material by a method ultrasonic working. The method includes forming a negative mold from a master sonotrode, forming a pre-working sonotrode from the negative mold, and ultrasonically working a workpiece using the pre-working sonotrode. The master sonotrode is then used to ultrasonically work the workpiece to form the dental restoration part.

Abstract: A process for producing ceramic dental prostheses, with which ceramic dental prostheses may be produced in the same diversity of shapes and with the same accuracy as metal dental prostheses. The process includes shaping an unfinished piece made out of 92.1 to 93.5 wt. % zirconium oxide, 4.5 to 5.5 wt. % yttrium oxide, 1.8 to 2.2 wt. % hafnium oxide, and reworking the piece to form a dental prosthesis by means of a rotating tool made of metal-bonded diamond grains.

Abstract: The present invention provides an addition-curable composition containing an inorganic, organic or organometalic compound of palladium in an amount effective to reduce the amount of hydrogen gas evolved in the reaction of the composition. A preferred embodiment is a dental impression material composition comprising: (a) an addition-curable compound; (b) a crosslinker; (c) a platinum-containing catalyst; and (d) a palladium compound. This generally provides a positive gypsum model of, for example, a dental impression that is substantially free of pits.

Abstract: Improved two component polymerizable polyorganosiloxane compositions are described, particularly for use in making dental impressions, having improved tear strength and wettability. Improved tear strength results from inclusion of a quadri-functional polysiloxane having a vinyl content of 0.16 to 0.24 m-mole/g. Working time is maintained by including sufficient amounts of a retarder composition that delays onset of the vinyl polymerization. Wettability is improved by including a surfactant resulting in a surface contact angle with water at three minutes of less than 50.degree.. The surfactant chosen has an HLB of 8-11, such that the wetting contact angle is achieved within less than two minutes and remains wetting throughout the working time of the impression taking, substantially improving the impression making process.

Abstract: A process for the extrusion of plastic plates with very finely structured surface using an extrusion system which is equipped with an extruder and a three roll polishing stack containing a roller with the structuring surface. The system is designed for coextrusion and the plastic plates are produced via two extruders as a coextrudate CX from a highly viscous basic molding compound BF and a low viscosity molding compound NF which is extruded on BF. The surface of said plates is structured via the three roll polishing stack. Fresnel lenses produced by the process may be used in solar collectors.

Abstract: A flexible single- or multilayer non-oriented or mono- or biaxially oriented film in which at least one layer comprises a cycloolefin copolymer, wherein the cycloolefin copolymer has a mechanical loss factor (tan .delta.) of .gtoreq.0.015 at 50.degree. C. below the glass transition temperature.

Abstract: A roll-shaped mold for forming an information recording medium has a pattern forming layer formed into a film on a roll-shaped mold substrate and having a pattern for formation of a groove for a track on a resin substrate for the information recording medium by heat molding on the circumferential wall of the pattern forming layer.

Abstract: The artificial tooth blanks made by series production involve a dentin-colored fired dental ceramic composition including a previously compression-molded hard core and optionally a retention, wherein the size of the artificial tooth blank is reduced over that of the corresponding finished artificial tooth and the artificial tooth blanks do not contain an enamel layer. The retention may involve one or more high-melting shells incorporated by firing and containing high-melting retention pins soldered therein after firing, wherein the retention pins as well as the solder are stable under the melting conditions for dental ceramic compositions for bridges and crowns, and especially so in the presence of air as well.

Abstract: A method and apparatus for forming "seamless" retroreflective sheeting is described. At least two mold surfaces are used, each having alternate areas of arrays of prism recesses and spaces. In a first step, prisms are formed in one of the mold surfaces and applied to a base film or web. Next, prisms are formed on the second mold surface and applied to the spaced areas left in the first step.

Abstract: A drug delivery ophthalmic insert prepared by forming a water soluble solid polymer into a paste by the addition of a small fixed amount of water, drying the paste and then sectioning the paste into a plurality of rod shaped inserts is provided. The insert is rendered suitable for prolonged and sustained delivery of medication to the eye since it is formed by the addition of a small amount of water and has a surface area less than about 3 mm.sup.2. Specific water soluble solid polymers which may be used include methylcellulose, hydroxyethyl cellulose, alginic acid and combinations thereof as well as mixtures of pilocarpine dispersed in methylcellulose and its combinations.

Abstract: In the present invention dental prostheses are cured without the use of dental flasks using an electrically heated pressure vessel. The dental prosthesis is cured while in a plaster chamber which is placed in a curing container with ambient water. The apparatus includes a perforated table for supporting the curing container during heat curing. The vessel has a lid for sealing the top, an inlet for injection of compressed air, an outlet for exhausting of compressed air, and an electrical resistance heating means for heating water held in the vessel. The curing container holds ambient temperature water at a level which covers the plaster chamber prior to submerging the curing container in the vessel containing water at a temperature of 90.degree. C. to 100.degree. C. The table supports the curing container in the vessel so that the top edge of the curing container is above the level of water held by the vessel.

Abstract: A method of forming an optical element on the surface of a substrate by ejecting a curable light guide forming liquid from a nozzle onto the substrate and curing the curable light guide forming liquid. A waveguide may be formed by moving the nozzle in a linear pattern over the surface of the substrate during ejection of the liquid from the nozzle. Curing the liquid may include exposing the liquid to ultraviolet radiation, and the radiation may be applied to only a small portion of the liquid. A multilayered waveguide may be formed by ejecting a further light guide forming liquid onto the first and curing it. A core and cladding may be formed simultaneously by ejecting core forming liquid from an inner tube and cladding forming liquid from an annulus about the inner tube. The waveguide may be formed in a groove, and a splitter may be formed by branching a second waveguide from a first, or by laying out two parallel waveguides and connecting them.

Abstract: Optical recording mediums are prepared by extrusion molding. In the extrusion molding, a thermoplastic resin heated to a given temperature is pressed between a roll stamper and a roll opposite thereto. A gap between the roll stamper and the roll is precisely defined by belt members fixed on each side of the roll where the roll does not come into touch with the thermoplastic resin. The joints of the respective belt members are formed at positions different from each other on the periphery of the roll. Alternatively the gap may be defined by cutting the roll substrate at a part on which the stamper member is fixed, or by interposing endless belts with a given thickness between the roll stamper and the roll. The stamper member provided on the roll stamper is reduced in stress, and has a surface precision of 10 .mu.m or less.

Abstract: The present invention provides a process using a roll stamper which molds a substrate sheet for information recording mediums by continuously transferring preformat patterns on a resin sheet. The roll stamper has the feature that the preformat pattern on the roll stamper has a value of b/a of greater than 1 when the length of the preformat pattern in the direction parallel to the direction in which the resin sheet is transported is defined as a and the length in the direction perpendicular thereto as b.

Abstract: A durable reusable polymeric mold for casting a microstructure sheet having an array of prism elements and a method for forming the microstructure sheet are disclosed. A polymeric mold has a facet side and a base side including an array of prism elements upon which an radiation cured sheet can be formed. A protective surface layer can be formed on the facet side of the polymeric mold. The protective surface layer is sufficiently opaque to radiation to protect the polymeric mold from damage when the curable sheet is formed and is sufficiently bonded to the polymeric mold to allow the cured sheet to be removed from the protective surface layer while not substantially removing the protective surface layer from the polymeric mold. The microstructure sheet can be used as a retroreflective structure.

Abstract: A process for the formation of dental restorations from glass-ceramic materials and the resulting dental restorations. In this invention, a dental restoration is prepared by placing a glass-ceramic material in a heat-pressure deformable crucible. Heat is then applied to the crucible in order to bring the glass-ceramic material to a working range at temperatures above its liquidus temperature. The crucible in which the glass-ceramic material is placed has heat-pressure deformation properties which are matched to the working temperature of the glass-ceramic material being heated. The heat deformation properties of the crucible must be such that when the glass-ceramic material in the crucible is in the working range the crucible is heat-pressure deformable without rupturing. Once the glass-ceramic material is heated to its working temperature, the crucible is brought into contact with a mold having a preformed cavity therein, the cavity being in the shape of the desired dental restoration.

Abstract: In a process and apparatus for the overall machining of a ceramic tooth restoration and producing of appropriate sonotrode crowns, these sonotrode crowns act on a workpiece one after the other, however from the same direction in space and are activated by the same ultrasonic transmitter. For the production of said sonotrode crowns, a geometrical model corresponding to the ultrasonic machining apparatus is used.

Abstract: A process for producing a cured composite and flexible light pipe, in which a molten cladding polymer and a crosslinkable core mixture are concurrently and coaxially extruded through a core mixture delivery tube of a coextrusion die, the extruded tubular cladding is filled with the extruded crosslinkable core mixture, and the crosslinkable core mixture is cured within the tubular cladding.

Abstract: An apparatus and method for producing an optical recording medium or an optical recording medium substrate sheet forms an photo-curable resin layer on at least one of a substrate sheet and a stamper which undergoes elastic deformation. The stamper bears a pattern corresponding with preformatting information and is brought into close contact with the substrate sheet wherein the photo-curable resin layer is interposed between them and cured.

Abstract: A process for the production of a ceramic prosthesis by forming a blank from a mixture of zirconium oxide and hafnium oxide of between 94.8% and 95.3% by weight, yttrium oxide of between 4% and 5.2% by weight, and any further oxide as a balance of less than 1% by weight, with a monoclinic proportion of below 5% by volume. The blank is put into the shape of the required prosthesis by means of a rotating tool of metallically bound diamond grains, using specific operating parameters for the tool.

Abstract: The present invention provides a novel dental composition and a method of making shaped dental articles therefrom via photoiniferter polymerization. The dental composition comprises acrylic photoiniferter block polymer, a monomer charge comprising free radically polymerizable acrylic monomer, and a filler and optionally includes pigments, sensitizers, medicaments, stabilizers, accelerators, etc. The dental composition is alternately exposed to a source of radiant energy and shaped in a desired manner in order to form a partially cured dental article. The partially cured dental article is then cured by a final exposure to the radiant energy source, providing a final cured article. The resultant reinforced acrylic copolymer system provides a shaped dental article which can be a denture base, a denture liner or a restorative.

Abstract: An orthodontic appliance such as a bracket is made of a polymeric material with reinforcing fiber structure embedded in the polymeric material. The reinforcing fiber structure includes relatively long filaments that extend about the perimeter of the bracket including the periphery of an archwire slot. In one embodiment, a method for making the bracket includes the steps of placing a tubular fiber preform in a mold assembly in an orientation aligned with a mesial-distal axis of the resultant bracket, and then closing the mold assembly in directions toward a central axis of the preform.

Abstract: Method and apparatus for manufacturing a cable having a channel for receiving energy conductors, e.g. optical fibers, with a channel cover which has a weak bond with the material forming the channel to facilitate removal of the cover. The plastic material which provides the channel and the plastic material which forms the cover are simultaneously extruded around optical fibers in two flows which are separated in advance of enclosing the fibers and which join with a weak bond as the flows meet thereafter. In the apparatus, the extruder has a tubular element through which the fibers are fed and the tubular element divides the plastic material into two separate flows in advance of a die. The tubular member is adjustable in position with respect to the die to balance or equalize the plastics flow.

Abstract: A method for preparing a substrate sheet for an optical recording medium has the steps of controlling a roll stamper having a preformat pattern on the peripheral surface thereof and a molding roll disposed with a predetermined gap between the same and the roll stamper so that they have a predetermined temperature, feeding a thermoplastic resin heated to a predetermined temperature to the gap from a means for extruding the thermoplastic resin disposed on the upstream side of the gap, while the roll stamper and the molding roll are rotated at a predetermined rotational frequency, and then molding the thermoplastic resin into a sheet by pressing the resin between the roll stamper and the molding roll to transfer the preformat pattern to the resin.

Abstract: An apparatus for producing an optical recording medium in a sheet form, having a resin melt-extruding device that forms a resin sheet, a first heated roller having a predetermined unevenness pattern, and a second heated roller disposed opposite thereto. Further, the apparatus has a conveying device that conveys the resin sheet, in a substantially melted state, between the first and second rollers, which transfer an unevenness pattern to a surface of the resin sheet. The apparatus also has a temperature control device to gradually cool the resin sheet.

Abstract: Process for cured composites and flexible light pipe, in which a molten cladding polymer and a crosslinkable core mixture are coaxially extruded through a coextrusion die, the cladding is filled with the crosslinkable core mixture, and the crosslinkable core mixture is cured within the cladding.

Abstract: Methods and apparatus for generating, and then precisely controlling, layer thickness gradients in multilayered polymeric reflective bodies are provided. The creation of such gradients is useful in tailoring multilayer bodies to reflect and/or transmit desired wavelengths of light. Both thermal and mechanical methods, as well as combinations thereof, are used.

Abstract: Disclosed in the present application is a method of curing a dental impression material by passing actinic light through a tray while the tray is in contact with the impression making composition, a new dental impression composition that is polymerizable by having an initiator activated by actinic light within the visible light range of 360 to 600 nanometers, a new composition of matter that is a compound having at least two terminal acrylate unsaturations and an organosilicone containing backbone and a new method of forming dental prosthetics by directly forming against the soft tissue of the oral cavity and then setting with visible light curing.

Abstract: Material having improved characteristics for filling endodontically prepared root canals is obtained by heat treating gutta percha based material at a temperature in the range of 210.degree. F. to 310.degree. F. for a period of two to twenty-four hours, the time being decreased as the temperature is increased.

Abstract: A loose tube element including a plastic sheath containing a grease-like material and an optical fiber or bundle of optical fibers or a ribbon of optical fibers is pulled from an extruder crosshead through a cooling bath and around a constant speed capstan. The loose tube element travels around the constant speed capstan a number of times and as it exits the capstan it is subject to a tensile force provided by a variable torque control capstan. The tensile force causes elongation of the plastic sheath, causes the optical fiber to be pulled taut and thereby controls the ratio of fiber length to sheath length within the loose tube element. While subjected to the tensile force, the element is subsequently cooled, causing the elongation of the plastic sheath to become permanent and thus fixing the fiber-to-sheath length ratio.

Abstract: The present invention provides a thermoplastic composition excellent in heat resistance and water resistance which comprises a thermoplastic saturated norbornene polymer which has a number-average molecular weight (Mn) of 50,000-500,000 and a weight-average molecular weight (Mw) of 100,000-2,000,000 which are measured by high performance liquid chromatography, and a molecular weight distribution (Mw/Mn) of 2.2 or more, and a volatile content of at most 0.3% by weight. The composition is suitable for optical materials, electroconductive composite materials and optical recording media.

Abstract: A method for covering at least one optical fiber with a protective layer comprises extruding the protective layer and embedding reinforcing elements in the protective layer to form a composite covering and simultaneously introducing the optical fiber into the composite covering. The method includes introducing a single waveguide or a plurality of waveguides, which may be formed into a bundle with a filling compound.

Abstract: A trimodal method of curing dental composite restorative materials involves the use of visible light illumination for the initial curing of the composite resin and a combination of dry heat and vacuum for the complete cure of the composite restorative materials. More specifically, the method for preparing dental restorative materials includes the steps of forming a dental restoration from a composite resin of a type conventionally employed in the dental profession, in which the composite resin includes a photosensitizing system for initiating polymerization of the composite resin upon exposure to visible light, an initiator for initiating polymerization upon application of heat and at least one filler; exposing the thus prepared restoration to a source of visible light to at least partially cure said composite resin and then subjecting the thus prepared restoration to a combination of heat and vacuum to complete polymerization of said complete resin.

Abstract: Along a plane sealing zone, a number of plastic film webs are sealed together under pressure and heat application. The plastic film webs run at equal or different distances from one another into the sealing zone and are guided over compression rolls. Between the compression rolls, which lie opposite each other in pairs, the plastic film webs are introduced and subjected to both pressure and heat. The plastic film webs are provided on one or both sides with sealing layers, which are incipiently melted by the action of heat, so that a sealing of the plastic film webs in layers one on top of the other occurs in the sealing zone.

Abstract: A roll stamper which molds a substrate resin sheet into an information recording media by continuously transferring preformat patterns on the substrate resin sheet, and a production process therefor. The preformat pattern on the roll stamper has a value of b/a of greater than 1 when the length of the preformat pattern in a direction parallel to the direction in which the resin sheet is transported is defined as a and the length in a direction perpendicular thereto as b.

Abstract: An apparatus and method for manufacturing a substrate sheet for information recording mediums having a roll stamper consisting of a flexible stamper having a pattern corresponding to a preformat for an information recording medium, the flexible stamper being fixed along the corresponding periphery of a roll substrate. A roll is placed opposite the roll stamper. A molten-resin sheet wider than the flexible stamper member is formed. The apparatus has means for bringing the edges of a resin sheet into contact with the roll substrate before releasing the resin sheet from the roll stamper. The temperature is controlled, so that a temperature difference on the surfaces of edges of a resin sheet and a preformat pattern transfer area of the resin sheet is kept within 30.degree. C. when the resin sheet is separated from the roll stamper after the molten-resin sheet has been pressed between the roll stamper and roll.

Abstract: A roll stamper for forming a substrate sheet for information recording mediums has a flexible stamper member having a pattern corresponding to a preformat for an information recording medium; a first fixing member and a second fixing member respectively joined to both ends of the stamper member in an integral form; and a pair of fit grooves capable of fittingly receiving the fixing members, formed in the periphery of a specular roll substrate in parallel to the axial direction of the specular roll substrate. The fixing members are so fitted to the fit grooves that the stamper member is fixed along the periphery of the specular roll substrate between the fit grooves.The first fixing member has a first member showing a coefficient of linear expansion substantially equal to the coefficient of linear expansion of the stamper member and a second member having a larger coefficient of linear expansion than the coefficient of linear expansion of the first member.

Abstract: An aligning jig for loose wires, which is equipped with the first and second retaining sections for retaining and temporarily fixing a plurality of loose wires, an arraying section which arrays the plurality of loose wires in an optional loading order in a plurality of arraying grooves arrayed widthwise and holds the loose wires in a predetermined order, at least one arranging section which arranges the plurality of loose wires, arrayed in the arraying section, to a preset specified width, and a fixing section which glues the plurality of loose wires, which have been temporarily fixed by the first and second retaining sections and arranged to the specified width, while maintaining the arranging order, thus fixing the wires to the specified width.

Abstract: A method for the production of a lamellar reflective polymeric body is provided and includes the steps of providing a first stream of a first heat plastified polymeric material and a second stream of a second heat plastified polymeric material, and encapsulating discrete portions of the first polymeric material in the second polymeric material by coextruding the polymeric materials to form a plurality of ribbon-like layers of the first polymeric material within a matrix of the second polymeric material to form the reflective polymeric body. The layers of the first polymeric material are arranged to have their major interfaces aligned substantially parallel to the major surfaces of the body such that at least 30% of light incident on the body is reflected. The ribbon-like layers may be further divided into a series of platelet-like layers to produce layers which are discontinuous in all major planar dimensions by passing the ribbon-like layers through a reciprocating feed plate or valve.

Abstract: A method and apparatus for marring the surface of a fiber optic substrate by feeding the substrate between a pair of rotating rollers. One of the rollers is coated with an abrasive. The second roller may be hard or have a deformable cover. Alternatively, one or both rollers may be serrated to produce a ripple pattern in the substrate. A hydraulic, pneumatic or other device is used for either manually and/or automatically adjusting the gap between the rollers. One or both rollers may also be heated to further enhance the marring action. A cam mechanism may also be used to adjust the pressure in the nip.

Abstract: A system and method for preparing an abraded fiber optic ribbon are provided. This system uses a flat abrasion panel containing a design, such as a company logo, and contacting it directly with a fiber optic ribbon, pressing devices to feed and press the panel and the fiber optic ribbon against each other as the design is being processed onto the fiber optic ribbon, and adjustable speed and differential pressure devices are used to drive the pressing devices. In addition, at least one of the pressing devices may be heated to enhance the processing of the pattern onto the fiber optic ribbon. Particularly, the pressing includes a first roller and a second roller defining a nip through which the panel and the fiber optic ribbon are being fed and pressed against each other. Alternatively, the pressing includes a first plate and a second plate defining a pressing zone in which the panel and the fiber optic ribbon are being fed and pressed against each other.

Abstract: A roll stamper for forming an information recording medium substrate has a stamper member having a pattern corresponding to a pre-format for an information recording medium formed in its obverse surface, fixation members fixed to both end portions of a reverse surface of the stamper so as to be integral with the stamper member, and fit grooves formed in a circumferential surface of a specular roll base parallel to the axis of the specular roll base. The fixation members are fitted in the fit grooves, and the stamper member is fixed on the circumferential surface of the specular roll base. The roll stamper also includes a mechanism for applying a tensile force to the stamper member. This roll stamper is used in an apparatus having an extruder for melting and extruding a resin to form a resin sheet and a specular roll facing the roll stamper to continuously form the information recording medium substrate.

Abstract: A dental refractory model material comprises as powdery components 5 to 20% by weight of a soluble phosphate, 5 to 20% by weight of magnesium oxide and 10 to 50% by weight of at least one selected from the group of alumina, zirconia, fused quartz, mullite, spinel and cordierite with the balance being crystalline quartz and crystobalite. The refractory model material also includes a liquid component such as a colloidal silica dispersion.

Abstract: Material having improved characteristics for filling endodontically prepared root canals is obtained by heat treating gutta percha based material at a temperature in the range of 210.degree. F. to 310.degree. F. for a period of two to twenty-four hours, the time being decreased as the temperature is increased.

Abstract: A method and apparatus for forming an optical cable includes an extruder for extruding a sheath on each light waveguide to form an independent light waveguide lead, a cooling device immediately following the extruder for cooling the light waveguide lead, which is then stranded to form a lead bundle.

Abstract: A method for forming a substrate sheet for optical recording media having a preformat on the surface is disclosed. This method has the steps of extruding a melted resin to form a melted resin sheet, pressing the melted resin sheet between a mirror roll and a resin roll prior to the curing of the melted resin sheet, thereby forming a resin sheet, the resin roll being disposed in the face of the mirror roll and being covered on the peripheral surface thereof with a resin, and forming a photocurable resin composition layer on the surface of the resin sheet with which the resin roll has come in contact, and forming the preformat on the photocurable resin composition layer.

Abstract: Plastic sheets of good optical quality suitable for use in the glazings of automotive vehicles, eye glasses etc., are made by depositing a hardenable liquid mass upon a taut moving ribbon of plastic which has been pretreated by tensioning and heating to remove wrinkles and creases which otherwise would render optically unsatisfactory the sheet formed on the ribbon upon hardening of the liquid mass. The temperature range within which the pretreatment should be conducted is 60.degree.-100.degree. C., with 70.degree.-90.degree. C. being preferred; the tension applied in the pretreatment should be a dekanewton or more per square millimeter, preferably 1.5-7.5 dekanewtons per mm.sup.2 ; and the time of pretreatment is at least a minute and preferably 5 or more minutes.

Abstract: Shaped bodies of transparent, polycrystalline alumina are produced in a green body is formed in a first step using pure, fine-grained alumina wherein, in the given circumstances, the green body is freed from the auxiliary agents used int he production by burning-out in a second step, wherein pretreat is carried out as a subsequent third step, and wherein the compaction to transparent, polycrystalline alumina takes place in a fourth step, in order to render the method more economical, it is suggested that the pretreatment be carried out in such a way as to produce a closed surface on the shaped body and that pressure from all sides at elevated temperature be used to compact the shaped body in the fourth step.