Abstract: A polycrystalline spinel sintered body is provided herein which is superior in light transmission, such that it can be used in an infrared light-transmitting window at a thickness of 2 mm or more. The present invention also provides a method of producing such light-transmitting spinel sintered body by hot pressing the spinel powders having high purity at temperatures of 1,200.degree. to 1,700.degree. C. and pressures of 100 to 500 kg/cm.sup.2 to compact the sintered body until a density of 95% relative to the theoretical density is achieved and then subjecting the thus sintered compact to a hot isostatic pressure treatment at temperatures of 1400.degree. to 1800.degree. C. and pressures of 500 kg/cm.sup.2 or more. Other variations of this basic method can be employed as disclosed in the specification. According to Applicants' method, a sintered body of high density and excellent light transmission can be achieved which is superior to prior art methods.

Abstract: A cellulose triacetate film excellent in both of the tear strength and the folding endurance can be obtained by casting a cellulose triacetate dope using a solvent mixture of methylene chloride with the other solvent in a ratio of 13 to 25 wt. % of the total solvent weight on a support of which the surface temperature is kept lower than 10.degree. C., and drying with controlling the drying conditions so that the content of volatile components in the film and the film surface temperature enter a particular region or so that the content of volatile components in the film and the shrinkage percentage of the film in the cross direction enter in a particular region. The film thus obtained is also excellent in flatness.

Abstract: In order to manufacture large-size porous shaped bodies of low density by swelling clay masses by supplying heat thereto, a plate-like, self-supporting clay mass is used, it is given an all-round support by direct acting, multiple linear solid body contact and at the same time maintained in constant motion relative to the support, and the surface of the swelling clay mass is subjected to constant oxidation by the supply of oxidizing hot gases to the surfaces of the plate-like moving clay mass.

Abstract: A method and device for shaping tubular workpieces from thermoplastic placs is disclosed. In the method, the workpiece to be shaped is inserted into a mold, heat is applied from the interior of the workpiece to heat the workpiece to the softening temperature of the plastic, this temperature is maintained until the workpiece assumes the shape of the mold, and the workpiece is left in the mold until it has cooled off. A flexible heating core is used to apply heat to the interior of the workpiece. The heating core has an insulating jacket with a sliding layer on its outer wall and a heating conductor winding located within the insulating jacket. A stress relief extends lengthwise in the middle of the heating core and outward of the heating core at one end. A receptacle is provided at the other end of the heating core for the stress relief.

Abstract: A mold for the manufacture of non-round glass shapes and method for making such molds. In molds for glass blowing and pressing, especially for producing non-round shapes where molten glass must be in contact with the mold for an extended time, an economical, heat resistant mold adaptable to any shape is produced by mixing defined ratios of water, hydraulic compound and amorphous fused silica to form a pourable composite mixture which is shaped into a mold by placing the mixture on or in a master pattern and curing the mixture at room temperature and then at elevated temperature.

Abstract: A fast, relatively inexpensive and simple method is disclosed for producing a finished plastic multifocal or progressive lens from a preformed lens which has a predetermined lens correction (i.e., curvature or prescription) at its optical center. The method comprises providing a mold; providing an optical quality resin composition; providing a preformed plastic lens contacting the mold such that the surfaces of the preformed lens and the mold form a cavity enclosing the resin composition; and curing the resin composition. The cavity formed by the preformed lens and the mold is shaped, among other purposes, (1) to correspond to the desired change in curvature, and (2) to ensure that the lens correction at the optical center of the resulting lens is substantially the same (preferably the same) as the predetermined lens correction at the optical center of the preformed lens.

Abstract: Ceramic substrates and a method for forming the ceramic substrates containing multi-level and interconnected circuit patterns of copper based conductors which are resistant to oxidation, said formation includes burn-out of binders in air. The oxidation resistant copper based conductors are composed primarily of copper and additives such as zinc, platinum and chrome.

Abstract: A heat-resistant alumina fiber mat contains an accumulated mass of alumina staple fibers and continuous alumina filaments. The accumulated mass is sewn with the continuous alumina filaments. A process for producing a heat-resistant alumina fiber mat includes accumulating a precursor of alumina staple fibers to obtain an accumulated mass, sewing the accumulated mass with continuous filaments to give a sewn mass and then sintering the sewn mass. The continuous filaments may be continuous alumina filaments or a precursor thereof.

Abstract: A compacted and highly oriented microstructure of the bulk-shaped Bi-Sr-Ca-Cu-O system oxide superconductor is obtained by the intermediate pressing method of the present invention. The growth rate of the high critical temperature phase in the bulk of Pb-doped Bi-Sr-Ca-Cu-O system oxide superconductor is also much improved and the sintering duration for obtaining a single phase having a high critical temperature is shorteneed by this method. Additionally, a higher critcal current density of Bi-Sr-Ca-Cu-O system oxide superconductor is obtained by the working under pressure process after cooling between a first and a second sintering step. Furthermore, the magnetic field dependence of the critical current density of Bi-Sr-Ca-Cu-O system oxide superconductor is also improved by the method of the present invention.

Abstract: A melt-blowing process for producing a fiber preferably a microfiber of a syndiotactic vinyl aromatic polymer, which comprises supplying a vinyl aromatic polymer having a high degree of syndiotacticity in a molten form from at least one orifice of a nozzle into a gas stream which attenuates the molten polymer into microfibers. Such microfibers are particularly useful in the field of high temperature filtration, coalescing and insulation.

Abstract: A highly sinterable powder consisting essentially of LaCrO.sub.3, containing from 5 weight % to 20 weight % of a chromite of dopant Ca, Sr, Co, Ba, or Mg and a coating of a chromate of dopant Ca, Sr, Co, Ba, or Mg; is made by (1) forming a solution of La, Cr, and dopant; (2) heating their solutions; (3) forming a combined solution having a desired ratio of La, Cr, and dopant and heating to reduce solvent; (4) forming a foamed mass under vacuum; (5) burning off organic components and forming a charred material; (6) grinding the charred material; (7) heating the char at from 590.degree. C. to 950 C. in inert gas containing up to 50,000 ppm O.sub.

Abstract: Methods are disclosed for the manufacture of individual small lenses, which may have gradient indices of refraction. A pedestal is provided having a conduit therein and an end surface the perimeter of which may be circular or elliptical. The perimeter is defined by a sharp edge. The pedestal is supported with the end surface horizontal and facing downwards. The intersection of the conduit and the surface, also defined by a sharp edge, forms an orifice through which at least one of the liquid monomers for forming the lens is fed. Gradient index small lenses are formed by suspending a first monomer from the horizontal end surface of the pedestal and then, via the orifice, introducing the second monomer at a rate which equals the rate of inter-diffusion of the second monomer into the first monomer. Alternatively, both monomers are both fed, in mixed condition, through the orifice in continuously varying proportions. The monomer(s) are cured in the pendant condition.

Abstract: An improved method and apparatus for incrementally stretching "zero strain" stretch laminate webs to impart elasticity thereto in the direction of stretching, at least up to the point of initial stretching. The "zero strain" stretch laminate material is formed of at least two plies of material which are either intermittently or substantially continuously secured to one another along at least a portion of their coextensive surfaces while in a substantially untensioned ("zero strain") condition. One of the plies is stretchable and elastomeric, while the second ply is elongatable, but not necessarily elastomeric. The second ply will, upon stretching of the laminate, be at least to a degree permanently elongated so that, upon release of the applied tensile forces, it will not return to its original undistorted configuration.

Abstract: Method for reducing the weight of molded golf club heads without changing their shape. Cavities of appropriate length and volume are created in the molded heads, extending from the rear face towards the front face thereof. Despite the cavities, the heads achieve a good restitution of energy, a good mass distribution, a low level of vibrations, and a good sound.

Abstract: A mould for cast moulding a contact lens comprises a first cup member having a male mould surface and a second cup member with a female mould surface. The two cup members form a piston and cylinder and are used in a pressure vessel so as to apply loading pressure to deflect the mould surfaces to maintain the surfaces in contact with a lens being cast. The mould is opened with the mould surface facing upwardly. Hydrating fluid is added to the first cup member and a cover sealed to the top of the first cup member.

Abstract: A method of producing segmented hollow body devices and the resulting products. The segmentation is accomplished by providing areas of increased cross-section around the circumference of the preform followed by axial compression thereof. These steps are followed by removal of the axial force resulting in a product which is segmented in accordance with the areas of increased cross-section and has a reduced free height.

Abstract: A fast, simple and relatively inexpensive method for forming disposable molds for use in casting optical quality lenses. A method of producing a disposable mold having a casting surface is disclosed which comprises providing a base master having a first contacting surface; providing a casting surface master having a second contacting surface having a shape corresponding to the shape of the casting surface; providing a resin composition; contacting the base master and the casting surface master such that the first and second contacting surfaces form a cavity enclosing the resin composition, wherein the cavity is shaped to correspond to the shape of the disposable mold; and curing the resin composition to form the disposable mold.

Abstract: A method is described for the production of a porous ceramic body and the subsequent infiltration of the body with a molten metal to produce an article having a reinforced metallic matrix. The article may be further worked by known techniques such as extrusion or forging, for example.

Abstract: A method for manufacturing an intraocular lens from a cell cast sheet of high molecular weight polymethylmethracrylate (PMMA). A lens blank having a lens generation area with a surface contoured to correspond to the desired contour of the finished lens is machined from the sheet of PMMA to a predetermined precompensated size larger than desired to acccommodate normalizing shrinkage. The lens blank is normalized by heating the blank in a vacuum oven. The vacuum is released from the oven by introducing dry nitrogen. A stamping die is provided. An optical embossing surface of the stamping die is contoured as a physical negative of the lens generation area and bears a physical negative of the desired optical surface structure of the lens, such as a multifocal diffractive zone plate. The embossing surface of the stamping die is forced into engagement with the surface of the lens blank at a predetermined stamping pressure and for a predetermined stamping dwell time.

Abstract: A polyamide yarn is disclosed which is at least about 85% by weight poly(.epsilon.-caproamide) and which has a relative viscosity of greater than 50, a tenacity of at least about 9.3 g/d, a dry heat shrinkage at 160.degree. C. of less than about 3 percent, a modulus of at least about 20 g/d, a toughness of at least about 240 g/d. %, a crystal perfection index of greater than about 82, and a long period spacing of greater than about 100 .ANG.. The process for making the yarn includes drawing of a feed yarn while heating to at least about 185.degree. C. in at least a final draw stage to a draw tension of at least 4.8 g/d, subsequently decreasing the tension while heating to at least about 185.degree. C. to produce a length decrease of between about 13.5 and about 30%, and cooling and packaging the yarn.