Abstract: A method for molding a polypropylene or a propylene copolymer having a syndiotactic structure which comprises the steps of melting, molding, if desired, quenching and then stretching a propylene homopolymer or a copolymer of propylene and a small amount of ethylene or another .alpha.-olefin which has a substantially syndiotactic structure, or a mixture of the same and a small amount of a polypropylene having a substantially isotactic structure. The molded and stretched article can be heated at a temperature of a molding temperature or more, while a load is applied to the article. Furthermore, the molded and stretched article, if desired, can be treated with a hydrocarbon vapor, while a load is applied to the article. The molded article obtained by the method of the present invention has a novel crystalline structure.

Abstract: Method of manufacture of ceramic materials which require stability in severely-corrosive environment having high alkali-metal activity, high sulfur/sulfide activity and/or molten halides at temperatures of 200.degree.-550.degree. C. or organic salt (including SO.sub.2 and SO.sub.2 Cl.sub.2) at temperatures of 25.degree.-200.degree. C. These surfide ceramics form stoichiometric (single-phase) compounds with sulfides of Ca, Li, Na, K, Al, Mg, Si, Y, La, Ce, Ga, Ba, Zr and Sr and show melting-points that are sufficiently low and have excellent wettability with many metals (Fe, Ni, Mo) to easily form metal/ceramic seals. Ceramic compositions are also formulated to adequately match thermal expansion coefficient of adjacent metal components.

Abstract: A method of producing a porous ceramic filter, using a cordierite precursor or starting composition including a talc powder component and a silica powder component, such that particles of the talc powder component and the silica powder component whose size is not less than 150 .mu.m constitute not more than 3% by weight of the starting composition, while particles of the talc and silica powder components whose size is not more than 45 .mu.m constitute not more than 25% by weight of the starting composition. A green body for the porous ceramic honeycomb filter formed of this starting composition is fired to react the starting composition to form cordierite and produce the desired porous ceramic honeycomb filter.

Abstract: A process of producing a honeycomb-structural body capable of preventing abrupt heat generation of molding aids and a pore-forming agent by increasing or decreasing the oxygen concentration in the firing atmosphere for the temperature region wherein the pore-forming agent and the molding aids hardly thermally decompose or easily thermally decompose, respectively; or promoting the firing by controlling the oxygen content in the firing atmosphere to be increased for the temperature region wherein the pore-forming agent and the molding aids are hardly burning, so as to reduce the temperature difference existing between the interior or exterior of honeycomb-structural body during firing, thereby to perform an optimal firing in a good condition to attain an uniformity of the specific properties in the interior and the exterior of such a honeycomb structural body by reducing the temperature difference of the same.

Abstract: A process and apparatus for drawing polyamide yarn in which the yarn having a lubricating finish is drawn while being spirally advanced in frictional contact with the outer surface of a yarn draw assist element. In such process and apparatus, the outer surface of the draw assist element moves at a speed at least 100 times slower than the speed at which the yarn is advanced. From the draw assist element, the yarn directly advances to a roll initial contact location on a pair of space-apart heated rolls and spirally advances on the rolls through at least one wrap in contact with the outwardly-facing surfaces of the heated rolls. The distance that the yarn spirally advances longitudinally in the wrap can be said to define the wrap advance on the rolls. The roll initial contact location of the heated rolls is oscillated by moving the outer surface of the draw assist element in relation to the pair of heated rolls to oscillate the wrap on the rolls a distance which is at least equal to the wrap advance.

Abstract: A microstructure-bearing composite plastic article can be superior, both in microstructure and in physical properties, when it is a composite of a tough, flexible substrate, at a surface of which is microstructure formed of a cured oligomeric resin having hard segments and soft segments, which cured resin is substantially confined to the microstructure portion of the composite. Such a composite plastic article can be made by depositing an uncured oligomeric resin composition onto a master negative molding surface, filling the cavities by moving a bead of the composition between a substrate and the master, and curing the deposited composition by ultraviolet radiation while keeping the temperature during curing from rising not more than about 30.degree. C. above a typical use temperature of the finished composite plastic article.

Abstract: A process for forming an intraocular lens with haptics having high fracture toughness mixing solid particles with an uncured polymer matrix and introducing the uncured mixture into a mold. Ultrasonic energy is then applied to the mold until the uncured mixture begins to solidify. Sufficient heat is then applied to the polymer mixture to completely cure the polymer. The cured polymer which will form the haptics, is then removed from the mold and a hole for forming the optic is formed in the cured polymer. An uncured polymer matrix suitable for use, when cured, as an optic, is then introduced into the hole and cured. An intraocular lens is then machined from the resulting cured composition.

Abstract: A process for the melt spinning of a fibre forming polymer into a filamentary yarn in which the spinning threadline is passed through a heated shroud located immediately below the spinneret, the threadline is cooled by an air current and then taken up at a speed of 5 km/min or more the improvement being that the temperature of the environment within the shroud, and in consequence the temperature of the filaments themselves, is progressively reduced, before the filaments in the threadline are cooled by the air current.

Abstract: Mica-containing ceramic composite having excellent characteristics such as capability of machining work, a small thermal expansion coefficient, high heat-shock resistant temperature difference as well as high heat deformation temperature, is prepared by: a) preparing powder mixture by blending 20 to 50% by weight of mica powder, 15 to 40% by weight of zinc oxide powder, 10 to 20% by weight of silica powder, 8 to 20% by weight of boric acid powder, and 4 to 20% by weight of cordierite powder; b) heating the powder mixture at a temperature of from 940.degree. C. to 1,050.degree. C. to prepare baked product; c) pulverizing the baked product into very fine powder to thereby obtain a shaping material; d) adding an organic binder to the shaping material to prepare a shaping composition; and e) shaping the shaping composition into a shaped body and heating a shaped body at a temperature ranging from 940.degree. C. to 1,050.degree. C.

Abstract: A fast, relatively inexpensive method and simple 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 disclosed method produces a finished lens which has a multifocal or progressive region without changing the lens correction at the optical center of the lens.

Abstract: A method of molding a plastic lens, in which: a pair of upper and lower molds are arranged to form a gap, corresponding to the thickness of the lens, therebetween; an adhesive tape is applied around the molds to define a cavity between the molds; and a plastic material is injected into the cavity. Optical axes of the molds are centered at respective positions of the molds. After the centering step, each of the molds is held with the centered optical axis. A height of each mold held is measured referring to a reference height. Displacements of the molds are determined on the basis of the measured heights of the molds and the reference height. The molds held are horizontally moved with the centered optical axes for axial alignment. The molds held are axially moved to form a predetermined mold gap between the molds on the basis of the determined displacements of the molds. Then, the adhesive tape is applied around the molds to define the cavity.

Abstract: Disclosed herein are poly(phenylene sulfide) fibers having a tensile strength of at least 3.5 g/d, a knot tenacity of at least 2 g/d, a loop tenacity of at least 3.5 g/d, the number of abrasion cycles until breaking in a flexing abrasion test of at least 3,000 times, and the number of repeated flexings until breaking in a flexural fatigue test of at least 150 times. A process for the production of poly(phenylene sulfide) fibers, which comprises melt-spinning a poly(phenylene sulfide), stretching the resultant unstretched filaments at a draw ratio of 2:1 to 7:1 within a temperature range of 80.degree.-260.degree. C., and heat-treating the stretched filaments for 0.1-30 seconds under conditions of a take-up ratio of 0.8:1 to 1.35:1 in a dry heat atmosphere exceeding 285.degree. C., but not exceeding 385.degree. C., is also disclosed.

Abstract: A process for producing high-temperature resistant and flame-retardant shaped articles of polyimide polymers of the general formula ##STR1## wherein A represents a four-valent group and R represents a divalent aromatic group, by heating a manipulatable sheet-like structure to a temperature in the glass transition range of between 280.degree. C. and 360.degree. and pressing it at pressures ranging between 10 bar and 500 bar. The polyimide shaped bodies obtained have densities of at least 1.30 g/cm.sup.3. Preferably, they may be completed as sheets having uniform thicknesses of between 0.1 and 6 mm.

Abstract: The invention concerns a roll or cylinder or roll coating for a pulp machine, paper machine, or paper finishing machine, in which application the roll or equivalent comprises a cylinder mantle of cast iron or steel or any other, equivalent metal, which bears the mechanical loads. On the rollor cylinder mantle, fixed to the outer face of the frame mantle, there is a resilient polymer coating, and onto said polymer coating a coating is fixed which is by several orders thinner than the radial thickness of the polymer coating. Said coating fixed onto the outer face of the polymer coating is a metal, ceramic, or cermet coating or a plastic coating. The invention further concerns a method for the manufacture of a roll coating in accordance with the invention as well as the use of such rolls and coatings.

Abstract: A porous low density inorganic oxide fibre of improved strength and flexibility has at least 25% of the porosity provided by axially aligned pores. The fibres are produced by spinning into fibres a spinning solution in which is incorporated a non-ionic surface active agent having a cloud point in the solution above the fibre spinning temperature and less than 20.degree. C. above the fibre spinning temperature, preferably within the range of 5.degree.-15.degree. C. above the fibre spinning temperature. The fibre may be an alumina fibre which can be free from silica and is useful as reinforcement in MMCs.

Abstract: A process for fabricating a multilayer ceramic circuit board which includes the steps of (i) providing a sintered ceramic substrate having optionally formed via holes already filled with a conductive paste or a conductive substance, (ii) optionally applying an insulating paste layer in a prescribed pattern on one side or each side of the ceramic substrate, (iii) then, providing a ceramic green tape and forming via holes in the green tape, (iv) applying a conductive paste to form a conductive pattern on one side of the green tape, (v) laminating the green tape to one side or each side of the ceramic substrate so that the conductive pattern of the green tape faces the substrate, (vi) optionally pressing and heating the laminate from step (v), and (vii) applying a conductive paste to form a conductive pattern on the other side of the green tape and filling the via holes of the green tape with a conductive paste, before or after step (v).

Abstract: A method of manufacturing a ceramic substrate with improved mounting pad location tolerances. The method begins with a green non-dimensionally stable ceramic base 10 to which at least one conductive layer 15, 16 such as a tungsten mixture is screen printed. The tungsten layer locationally defines a pattern including pads 15. This composite assembly is subsequently stabilized as in firing and a second insulating ceramic slurry layer with openings 29 located over the relative larger pads is screen printed on the stabilized composite assembly. This method eliminates tolerances in final mounting pad location due to unpredictable shrinkage and yet maintains excellent mounting pad adhesion since the entire pad overlays some portion of the tungsten pad.

Abstract: A method and apparatus for making aromatic heterocyclic polymeric fibers having enhanced compressive strength are disclosed. Individual polymeric fibers, while being made according to otherwise conventional methods, are full twisted as they are drawn from a spinnerette hole so that their internal fibrils and microfibrils become entangled. The twisting is performed before coagulation of the fibers. The entangled fibrils and microfibrils are believed to provide mutual support to adjacent fibrils/microfibrils to resist buckling under compression.

Abstract: A yarn component containing at least one filament is prepared by:selecting at least one partially oriented, undrawn synthetic filament having a birefringence of at least 20.times.10.sup.-3 and an elongation at break of 70-200%, andsubjecting the thus-selected filament or filaments to a heat treatment at 100.degree.-180.degree. C. under tension. The resulting yarn component has a degree of elasticity under a load of 5 cN/tex of less than 50%, which causes the yarn to be especially well suited for use in formable sheet structures.

Abstract: A process for longitudinally stretching a polymeric film having thickened longitudinal edges while the film is constrained in the lateral dimension by a plurality of successive pairs of grippers, the improvement comprising first guiding the film with a first group of gripper pairs having a predetermined clearance therebetween; and then gripping the film with a second group of gripper pairs with a predetermined amount of force. An apparatus for use in the process is also disclosed.