Abstract: A process that involves the in-line polymerization of olefinic monomer(s) and catalyst systems comprising a transition metal species that mediates the polymerization of the monomer(s) is disclosed. This process provides the immediate use of the resultant polymer without extensive further processing.

Abstract: A rapid prototyping process and apparatus by which prototype components can be fabricated for conceptual evaluations. The rapid prototyping process entails the steps of forming a prototype within a process chamber that generates the prototype on a platform of a build chamber through sequentially depositing a layer of material on the platform, fusing the layer of material together, and then lowering the platform so as to allow depositing of a subsequent layer of material on the platform. In this manner, the depositing, fusing and lowering steps are repeated until the desired prototype is obtained. Thereafter, the build chamber, housing the prototype, is detached from the process chamber, and the prototype is cooled while remaining within the build chamber. The prototype is preferably cooled within the build chamber using a nonreactive cooling medium that is caused to flow around the prototype.

Abstract: A bubble stripping and coating apparatus for stripping entrained gas from the surface of a fiber, then coating the fiber with a coating material having a bubble stripping and coater body and a die assembly. The bubble stripping and coater body has a bubble stripping gas entrance for providing a bubble stripping argon gas to a bubble stripping gas chamber for stripping entrained gas from the fiber and having a die assembly bore. The die assembly is arranged in the die assembly bore, and has a guide die having a lower guide die opening with a diameter of less than 0.016 inches.

Abstract: A gas nozzle for a gas assisted injection molding system includes a body having an inlet in fluid communication with a source of pressurized gas, an outlet through which the gas leaves the nozzle and a passage extending between the inlet and the outlet. The outlet includes a plurality of apertures arranged in a predetermined manner relative to one another such that the flow path through the outlet approximates a 1/8 inch hole but does not clog with resin over successive plastic injections into the mold.

Abstract: The invention features polymers with increased order, and methods of making them featuring a dense gas.

Abstract: A method of forming a hollow ceramic article includes the steps of providing a mold having a wall defining a cavity and injecting into the cavity through an inlet through the cavity wall a quantity of a slurry sufficient to fill the cavity. The slurry is formed by a molten thermoplastic binder and ceramic particles suspended in the binder. The portion of the slurry in contact with the cavity wall is cooled to solidify the same, while leaving still molten the portion of the slurry not in contact with the cavity wall. Gas is injected into the cavity through an inlet through the cavity wall and into the still molten slurry portion to force the same out of the cavity through an outlet through the cavity wall. This leaves therein only the gas and a hollow green piece formed from the solidified slurry portion.

Abstract: A process for providing degassed complementary concave and convex lens molds to filling and mold assembly stations in a continuous or semicontinuous automated soft contact lens manufacturing system. The process includes injection molding the lens molds, immediately transferring the lens molds to an inert gas atmosphere, degassing the lens molds, and filling the lens molds with a polymerizable monomer under the inert gas prior to mold assembly.

Abstract: The invention is directed to a molding apparatus, including a cylinder having an interior sidewall and a fluid inlet, and defining an inner cavity. A porous plate is disposed within the inner cavity, and is disposable in a loading position wherein the inner cavity is divided into a fluid flow chamber and a material chamber. A ram having an outside diameter which is less than the diameter of the cylinder interior sidewall is slidable within the cylinder.

Abstract: An apparatus and process for expanding polymeric tubing including a bubble of trapped gas within the polymeric tubing. The tubing is expanded by creating a pressure differential between the inside and outside of the tubing such that the pressure inside the tubing is greater than the pressure outside the tubing, thereby causing the tubing to expand. It is possible with the present invention to compensate for loss of gas pressure, thereby increasing the amount of tubing which can be expanded without ceasing production and restarting the process.

Abstract: By kneading a composition containing a filler and an organic forming binder, extruding the composition, baking the composition in a non-oxidizing atmosphere, there is obtained a first baked lead containing, as a binder, a carbon obtained by the carbonization of the organic forming binder. Then, by heating the first baked lead in an oxidizing atmosphere to remove the binder carbon, there is formed a second baked lead composed of at least the filler. The pores of the second baked lead are impregnated with a solution containing perhydropolysilazane, subjecting the lead to a heat treatment in an inert atmosphere or an ammonia gas atmosphere to form a third baked lead containing the resultant silicon nitride. Finally, ink is filled into the pores of the third baked lead to provide a baked color pencil lead.

Abstract: A method of injection molding for use with an injection molding machine includes: a) generating pressurized gas and pressurized moisture within molten plastic as plastic pellets are plasticized in the injection molding machine, the pressurized gas and the pressurized moisture having a total pressure defining an internal counterpressure within the molten plastic; (b) pressuring air within a cavity of a mold in the injection molding machine to an air pressure level which is substantially equal to the internal counterpressure in order to counterbalance the internal counterpressure as the molten plastic is injected into the cavity, thus providing a substantially pressure balanced molding environment for the plastic; and (c) maintaining the air pressure level in the cavity substantially constant as the molten plastic is injected into the cavity.

Abstract: A process for the extrusion of polyethylene having a broad molecular weight distribution wherein the polyethylene is prepared in pellet form, said extrusion taking place in a pelletizing extruder having one or more zones essentially filled with polyethylene and two or more zones partially filled with polyethylene including(i) introducing the polyethylene into the extruder at a temperature sufficient to melt the polyethylene; (ii) introducing a mixture of an inert gas and oxygen into each partially filled zone wherein the mixture contains about 1 to about 21 percent by volume oxygen based on the volume of the gaseous mixture; (iii) passing the molten polyethylene through each zone at melt temperature; and (iv) extruding the polyethylene into pellets and cooling same.

Abstract: A method of injection molding for use with an injection molding machine (10) includes: (a) generating pressurized gas and pressurized moisture within molten plastic as plastic pellets are plasticized in the injection molding machine (10), the pressurized gas and the pressurized moisture having a total pressure defining an internal counterpressure within the molten plastic; (b) pressuring air within a cavity (30) of a mold (22) in the injection molding machine (10) to an air pressure level which is substantially equal to the internal counterpressure in order to counterbalance the internal counterpressure as the molten plastic is injected into the cavity (30), thus providing a substantially pressure balanced molding environment for the plastic; and (c) maintaining the air pressure level in the cavity (30) substantially constant as the molten plastic is injected into the cavity (30).

Abstract: Provided is a method for charging a powdery heat insulator into a thermally insulated, double-shelled tank between its inner vessel and outer vessel. The method comprises causing a powdery heat insulator to flow together with water into a space between the inner vessel and outer vessel of a thermally insulated, double-shelled tank, discharging the water in said space, and then drying the powdery heat insulator. The pressure in the space is then also reduced. The drying of the powdery heat insulator can be carried out by heating either the inner vessel or outer vessel, or both of these vessels, or by inert gas flow, such as nitrogen gas.

Abstract: Processes for fabricating substantially void-free polymeric articles are provided. In one embodiment, a polymer melt is formed followed by extrusion through a die to form a polymeric extrudate. The polymeric extrudate is directly discharged vertically upward into an open-ended mold the open-ended mold having a longitudinal axis oriented substantially vertically. The polymeric article is cooled and removed from the mold. In a further embodiment, a mold is loaded with polymeric particles. The mold is oriented such that its longitudinal axis is substantially vertical. A vacuum is drawn on the loaded mold followed by heating the loaded mold above the melting point of the polymeric particles. After the polymeric particles are melted, the loaded mold is charged with an inert gas to above ambient pressure to collapse any remaining voids. The loaded mold is slowly cooled to form a polymeric article. Oriented polymeric bioabsorbable cannulated surgical articles and a method of making same are provided.

Abstract: An acylated cellulose film having a high optical isotropy and uniformity is produced by dissolving an acylated cellulose in a solvent substantially free from water and including, as a principal component, 1,3-dioxolane in a ratio in weight of the acylated cellulose to the solvent of 10/250 to 10/15; spreading the acylated cellulose solution on a film-forming surface of a support; and drying, for example, initially drying the spread solution layer on film-forming surface so as to reduce the content of the residual solvent in the resultant film to 5 to 30% by weight; removing the resultant residual solvent-containing film from the film-forming surface; and finally drying the removed film, while allowing the film to shrink in the transversal direction thereof, at a drying temperature controlled continuously or intermittently to a level satisfying the relationship (I): (Tg'-50.degree. C.).ltoreq.T.ltoreq.(Tg'+20.degree. C.) (I), wherein T is the drying temperature (.degree.C.

Abstract: An apparatus for causing the polymerized excess monomer to separate from a molded lens by increasing the surface energy of the flange area of one mold piece, causing the polymerized excess monomer to stick thereto. Specifically when manufactured under inert atmosphere conditions, a particular manifold is needed to supply an oxygen bearing gas, air, to the area to be treated while preventing the oxygen from contaminating the lens manufacturing area of the molds or diluting the nitrogen atmosphere of other lens process areas. It has been found that generation of the ionized oxygen by means of a corona treatment electrode sufficiently increases the adherence of the polymer to the mold piece so treated.

Abstract: An apparatus for producing a green compact includes a circuit that circulates die assemblies, each of which contains a rubber mold having rubber in at least its side portion. The apparatus also includes a high density filling device that has a feeder for feeding powder into the rubber molds; a pusher or a vibrator or both a vibrator and a pusher; a die press machine configured to impart a compaction force sufficient to produce the green compact to each of the circulating die assemblies in succession; and a device for removing the green compact from each rubber mold. The high-density filling device, the die-press machine and the removing device are successively arranged along the circuit. Each of the circulating die assemblies has sufficient structural integrity to withstand the compaction force because all structure necessary to withstand the compaction force is present in the circulating die assemblies.

Abstract: The specification describes a method for producing high density sintered silicon nitride (Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then pre-sintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing (HIP) in an inert gas atmosphere of 1500.degree.-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4 above 500.degree. C.

Abstract: In a method for producing a three-dimensional object wherein the object is produced layer by layer by applying a layer of a material which can be solidified by irradiation with electromagnetic radiation and subsequently solidifying the layer at the points corresponding to the object by irradiation the problem is encountered that the production process is considerably delayed by long heating and cooldown times within the apparatus used for the production. According to the invention this problem is solved by irradiating and thereby solidifying in each layer a region of the material surrounding the object so as to produce a container wall (26) for the material (21).

Abstract: Process for direct production of shaped packaging material made of thermoplastic polyesters with no effect on the taste of foods packaged in them, where the diol component of the polyester consists of at least 70 wt % ethylene glycol, and the polyester is produced in the presence of the usual catalysts plus additional cobalt or cobalt and manganese compounds and phosphorus compounds. An inert gas is introduced into the polyester melt and distributed uniformly in the melt immediately after its discharge from the polycondensation reactor, 0.05 to 1.0 wt % of an amide compound with a low volatility is added to the polyester melt directly next to the gas inlet. Finally, the polyester melt is subjected to a vacuum degassing immediately before the shaping apparatus and the melt is sent directly to the shaping apparatus within a maximum of 30 minutes after its discharge from the reactor at a maximum temperature of 35.degree. C. above the crystallite melting point of the polyester.

Abstract: Multiple sequential chemical reactions on a polymeric feedstock are carried out in an extruder with multiple reaction zones. Each reaction zone has means for introduction of reagents, for mixing of reagents with polymer and for removal of by/co-products or unreacted reagents.

Abstract: In a method and an apparatus for producing three-dimensional objects by layerwise solidification of a material the problem is encountered that, in particular when using powdery or pasty material, a material layer having an exactly adjusted thickness can not be generated in a sufficiently fast manner. In order to solve this problem, it is proposed to scrape the material by means of a vibrating wiper member (21, 22) when applying the material or to provide a movable container (13) used for applying the material with such wiper members (21, 22) at the lower side thereof.

Abstract: A central supervisor controls a manufacturing process fabricating fibrous, cementitious structural products requiring very small dimensional tolerance, high strengths, controlled reinforcement alignments, multiple undercuts, and complex shapes not possible using casting, forming, or extrusion. The process uses electrical and magnetic fields to align and direct free floating, cement coated, magnetic, and nonmagnetic fibers, filaments, and elongated fragmented particles onto moving shaping devices. These devices have magnetized shaping tool surfaces to receive aligned materials in layers parallel, perpendicular, and angular to shaping surfaces. Controlled materials, cement, setting agents, magnetic fluxes, and electrical charges make possible better bonding of cements with materials and consolidation of nonplastic matrices. Sliding, and rotating shaping tools make multiple undercuts on faces and edges of the products.

Abstract: A rapid prototyping process is provided by which prototype components can be fabricated that are suitable for conceptual evaluations. The rapid prototyping process of this invention is more efficient than comparable prior art processes, in that the previous requirement to completely process a prototype article within a single process chamber is eliminated, such that different process steps can be conducted simultaneously on different articles within a single process system. The process entails the steps of forming a prototype within a process chamber that generates the prototype through successively depositing and sintering individual layers of a powder material that fuses together so as to form the prototype. The prototype is then removed from the process chamber and cooled within a separate cooling chamber through which a nonoxidizing cooling medium flows.

Abstract: A method of manufacturing an integral one-piece needle, the method comprising feeding a polymeric resin into a mould cavity and injecting a fluid under pressure into at least a portion of the cavity to eject therefrom the central region of the polymeric resin. This creates an annulus of polymeric resin having an orifice therethrough, the annulus of polymeric resin forming the cannula of the needle, the mounting hub being provided by the remaining portion of the cavity.

Abstract: Methods of deblocking a polymeric article from a mold and/or removing undesirable materials from a polymeric article by applying supercritical fluids to the polymeric article. A preferred process is the treatment of ophthalmic lenses, such as contact lenses. Supercritical fluid, composed primarily of carbon dioxide, is applied to a contact lens affixed to a mold subsequent to the polymerization step. The application of supercritical fluid (SCF) causes the lens to efficiently and consistently separate from the mold, removes undesirable materials such as unreacted monomer, oligomers, or residual solvents from the lens core, and/or cleans the lens surface of adhered debris.

Abstract: The specification describes a method for producing high density sintered silicon nitride(Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then presintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing(HIP) in an inert gas atmosphere of 1500-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 -Al.sub.2 O.sub.3 -MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4 above 500.degree. C. for a while.

Abstract: A method for producing an aromatic polycarbonate comprises introducing to an introduction zone (having a perforated plate) a) a molten monomer mixture of an aromatic dihydroxy compound and a diaryl carbonate, or b) a molten prepolymer obtained by a process comprising reacting an aromatic dihydroxy compound with a diaryl carbonate, and allowing the monomer mixture or prepolymer in the molten state to pass downwardly through the perforated plate and fall freely through a free-fall polymerization reaction zone, thereby effecting polymerization of the monomer mixture or prepolymer during the free-fall thereof. Colorless and high quality aromatic polycarbonates are thus stably produced at a high polymerization rate for a prolonged period of time, using an apparatus which has excellent sealing properties under high vacuum and maintenance of which is easy.

Abstract: Low cost broadband infrared windows are fabricated using a near net shape process which greatly reduces the cost of machining and grinding window materials. The fabrication of zinc sulfide (ZnS) IR windows uses ceramic powder processing to avoid the expensive prior art chemical vapor deposition method. Further, the invention involves a means of hardening and strengthening ZnS as part of the powder process, with IR transmission performance comparable to undoped CVD-prepared ZnS. The compositional modification used in the practice of the invention involves the introduction of gallium sulfide (Ga.sub.2 S.sub.3) as a second phase which acts to toughen and harden the ZnS. The process of the present invention achieves a hardening effect without degrading the IR transmission properties also by means of controlling the polycrystalline microstructure grains to a very small size. At the same time, porosity, which strongly degrades IR transmission, is minimized by full densification.

Abstract: An apparatus and method for causing the polymerized excess monomer to separate from a molded lens by increasing the surface energy of the flange area of one mold piece, causing the polymerized excess monomer to stick thereto. Specifically when manufactured under inert atmosphere conditions, a particular manifold is needed to supply an oxygen bearing gas, air, to the area to be treated while preventing the oxygen from contaminating the lens manufacturing area of the molds or diluting the nitrogen atmosphere of other lens process areas. It has been found that generation of the ionized oxygen by means of a corona treatment electrode sufficiently increases the adherence of the polymer to the mold piece so treated.

Abstract: Multiple sequential chemical reactions on a polymeric feedstock are carried out in an extruder with multiple reaction zones. Each reaction zone has means for introduction of reagents, for mixing of reagents with polymer and for removal of by/co-products or unreacted reagents.

Abstract: A process for producing a modified polypropylene having a very high melt tension and superior stiffness and moldability, and a molded product obtained by using the modified polypropylene are provided.which process includes adding 0.05 to 10 millimols of a cross-linking auxiliary to 100 g of a linear polypropylene, mixing them, irradiating ionizing radiations to the mixture so as to give an absorbed dosage of 1 to 20 kGy, and successively heat-treating the resulting material at 80.degree. to 350.degree. C.,which modified polypropylene has(A) a degree of branching of substantially 1,(B) a relationship between its melt tension (MS) at 230.degree. C. and its intrinsic viscosity (.eta.) measured in tetralin at 230.degree. C. expressed by an inequalitylog (MS)>4.24.times.log [.eta.]-0.915, and(C) a percentage of extraction residue in boiling xylene of 1% by weight or less.

Abstract: Tooling and method for gas assist injection molding of plastics material into a hollowed part in which a mold chamber formed between stationary and movable mold tools is initially charged with an inert gas to provide a resistance force against the flow front of a short shot of plastics melt subsequently injected into the cavity and supplied with a pressurized assist gas so that the velocity of the flow front of the short shot expanded by the assist gas in the mold chamber is modulated by the controlled release of the retarding chamber charge gas to prevent blow out of the short shot while eliminating flow hesitation lines to improve molded part appearance and uniformity of part wall thickness.

Abstract: The apparatus includes an air compressor (13), which is cooled by direct oil injection, and an air cooler (14) connected downstream of it which serves as a condensate separator. Connected to it is a heat exchanger (18) which is heated by the waste heat from the oil discharged from the air compressor (13). The temperature of the air is raised thereby to a level at which the separators (4) downstream thereof develop their optimum efficiency. The nitrogen flowing out of the separators (4), the purity of which is predetermined by a downstream throttle (3), flows into an inflatable reservoir (5) which is connected to the suction side of a high pressure compressor. The latter discharges into a high pressure storage container which for its part supplies an injection moulding machine. The nitrogen is conveyed in a closed circuit between the injection moulding machine and the inflatable reservoir.

Abstract: The present invention relates to a diamond vibration plate for a speaker having high sound velocity or E/.rho. and which is superior in high-pitched tone performance. Conventional diamond vibration plates which are made overall from crystalline diamond were apt to split or break at a flange due to the high rigidity. According to the present invention periphery of the flange is circularly cut by laser beams to eliminate rugged circumference. The laser treatment also converts the crystalline diamond of the flange into non-diamond carbon. The resulting vibration plate with a central spherical part of crystalline diamond and a periphery of a flange of non-diamond carbon excels both in high frequency property and mechanical strength.

Abstract: Multiple sequential chemical reactions on a polymeric feedstock are carried out in an extruder with multiple reaction zones. Each reaction zone has means for introduction of reagents, for mixing of reagents with polymer and for removal of by/co-products or unreacted reagents.

Abstract: A method of manufacturing a superconductor is carried out by first preparing a material composed of Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7. This material is heated/molten in a platinum crucible. A melt thus obtained is drawn out from a high-temperature frame provided above the platinum crucible and heated to a temperature exceeding the melting point of the material. The melt thus drawn out is cooled by natural standing, to be solidified. As the result, an elongated superconductor composed of Y.sub.1 Ba.sub.2 Cu.sub.3 O.sub.7 can be obtained. This superconductor enters a superconductive state at 90 K.

Abstract: A liquefying apparatus for melting solid materials has a hopper with a coiled heating element disposed therein which supports and melts the solid materials into a liquid form. The liquid is stored below the heating element in a bottom section of the hopper, and is continually adjusted to a predetermined level, in order to insure that 1) the liquid in the lower section has a substantially constant temperature distribution and 2) a skin or film is not formed on the heating element which would reduce the liquefying rate.

Abstract: The purity and toughness of a batch of diamond grains is increased by separating a portion containing undesirable inclusions form a remaining higher purity portion and annealing the higher purity portion in a reducing atmosphere for a sufficient period of time to enhance the toughness of the higher purity portion.

Abstract: A process for injection molding of thermoplastic materials which includes a nozzle body having a bore to provide a flow path for molten thermoplastic. One end of the nozzle body is adapted for connection with a sprue of an associated mold body, and the other is adapted for connection with an end of an associated injection molding machine. The nozzle body has a shut-off valve fluid pin housing adapted for reciprocating movement in the nozzle bore to control the flow of plastic through the nozzle body. The shut-off valve fluid pin housing also includes a body having a fluid pin with a tip portion and a fluid passage formed in the body and open at the tip portion and the other end of the fluid passage communicating with a source of two pressurized fluids, one in vapor and liquid phase and another in gas.

Abstract: With the method of processing liquids, fine to very fine organic and/or inorganic granular particles are used, whereby pursuant to the invention the particles are mixed and compressed together in a first step to form an agglomerate that is heated at least to a temperature that is near the melting point thereof. The particles are thereby fixed in place by being subjected to a process similar to sintering for a suitable length of time, whereupon the resulting agglomerate is screened, or reduced in size in a grinder, to a granular size that is suitable for an intended use. This enables stabilizing and filtering aids to be produced with predetermined or predictable physical or chemical properties that are suitable for specific processes.

Abstract: A method for producing continuously a long reinforced hose having a plurality of reinforcement layers. An inner reinforcement layer is formed by braiding steel wires or fibers on a mandrel and a rubber is extruded onto the inner surface of the reinforcement layer to form an inner rubber layer therein. An adhesion rubber is then extruded onto the outer surface of the inner reinforcement layer to form an adhesion rubber layer thereon and at the same time an outermost reinforcement layer is formed on the adhesion rubber layer by braiding on a mandrel. The unvulcanized hose including the respective layers is pulled at a speed higher than the braiding speed of the outermost reinforcement layer, thereby firmly joining the reinforcement layers and then pulled at a lower speed but still higher than the braiding speed, thereby more firmly urging both the reinforcement layers to each other.

Abstract: The invention relates to a method in connection with a process for insulating or sheathing conductors or the like, wherein plastic material is extruded into at least one layer on the surface of the conductor (1), and the conductor coated with the plastic material (2, 3, 4) is cooled in a predetermined manner. To avoid problems caused by the shrinking of the plastic material, after the cooling of the conductor (1) and the plastic material in vicinity to it to a predetermined level in the insulating or sheathing process, the surface layer of the plastic material and the plastic material portions in vicinity to it are reheated to a predetermined temperature in a pressurized space filled with a medium.

Abstract: The specification describes a method for producing high density sintered silicon nitride(Si.sub.3 N.sub.4) having a relative density of at least 98%. In a first step, silicon nitride powder is compacted into a desired shape. It is then presintered in a second step, generally, under normal pressure to obtain a presintered body having a relative density of at least 92%. In a third step, the presintered body is subjected to a hot isostatic pressing(HIP) in an inert gas atmosphere of 1500-2100.degree. C. and of nitrogen gas partial pressure of at least 500 atm. Since the presintering does not require any capsule, it is possible to produce high density sintered Si.sub.3 N.sub.4 of complex configurations. As a sintering aid, Y.sub.2 O.sub.3 --Al.sub.2 O.sub.3 --MgO system sintering aid is particularly effective. To improve the strength of sintered Si.sub.3 N.sub.4, it is effective to add a heat treatment step after the HIP and maintain the temperature of the sintered Si.sub.3 N.sub.4, above 500.degree. C.

Abstract: A method of injection molding for use with an injection molding machine includes: (a) generating pressurized gas and pressurized moisture within molten plastic as plastic pellets are plasticized in the injection molding machine, the pressurized gas and the pressurized moisture having a total pressure defining an internal counterpressure within the molten plastic; (b) pressuring air within a cavity of a mold in the injection molding machine to an air pressure level which is substantially equal to the internal counterpressure in order to counterbalance the internal counterpressure as the molten plastic is injected into the cavity, thus providing a substantially pressure balanced molding environment for the plastic; and (c) maintaining the air pressure level in the cavity substantially constant as the molten plastic is injected into the cavity.

Abstract: A method and apparatus for making an ophthalmic lens pumps monomer into one end of a gas permeable tube along its interior length while a chamber surrounding the gas permeable tube is maintained at a subatmospheric pressure by means of a vacuum pump. Preferably, the gas permeable tube is made of silicon rubber. Static mixers introduce mixing into the flow of the monomer within the tube in order to expose the bulk of the monomer to the gas permeable walls of the tube. Under such conditions in the gas permeable tube, the majority of the dissolved gasses are removed from the monomer and continue to be drawn out of the chamber by the pump connected to the chamber. The degassed monomer is then transferred into a mold where it is polymerized into an ophthalmic lens.

Abstract: This invention relates to a process for the preparation of polycrystalline silicon ingots by providing a first layer of coating on the inside walls of a mold with a slurry of silicon nitride powder in an organic binder dissolved in a solvent; charging the said coated mold with silicon pieces along with calcium chloride or/and calcium fluoride; heating the mold to a temperature in the range of 1420.degree.-1500.degree. C. so as to melt the silicon, by keeping the mold inside the furnace; bringing down the temperature of the mold to a temperature 5.degree.-10.degree. C. above the melting point of silicon; withdrawing the mold containing the melt downwardly and slowly from the hot zone of the furnace so that the solidification of the melt starts from the bottom of the mold and proceeds towards the top as the withdrawal continues till all the melt solidifies; cooling the mold to the room temperature under inert atmosphere and removing the polycrystalline silicon ingot from the mold.

Abstract: A method for producing continuously a long reinforced hose having a plurality of reinforcement layers. An inner reinforcement layer is formed by braiding steel wires or fibers on a mandrel and a rubber is extruded onto the inner surface of the reinforcement layer to form an inner rubber layer therein. An adhesion rubber is then extruded onto the outer surface of the inner reinforcement layer to form an adhesion rubber layer thereon and at the same time an outermost reinforcement layer is formed on the adhesion rubber layer by braiding on a mandrel. The unvulcanized hose including the respective layers is pulled at a speed higher than the braiding speed of the outermost reinforcement layer, thereby firmly joining the reinforcement layers and then pulled at a lower speed but still higher than the braiding speed, thereby more firmly urging both the reinforcement layers to each other.

Abstract: The invention provides a method of producing ultra-fine particles and an apparatus therefor. A particle carrier is moved in a chamber which is decompresed and charged with inert gas. An evaporable material is heated so as to deposit evaporated ultra-fine particles onto a part of the moving particle carrier. The deposited ultra-fine particles are collected from the part of the moving particle carrier while evaporated ultra-fine particles deposit onto another part of the moving particle carrier.