Abstract: Shaped hydrogel articles such as soft contact lenses are prepared by (1) molding or casting a polymerization mixture comprising: (a) a monomer mixture comprising a major proportion of a hydrophilic (meth)acrylate ester such as 2-hydroxyethyl methacrylate, and a cross-linking monomer; and (b) a water-displaceable diluent, wherein said diluent has a viscosity of at least 100 MPa Sec at 30.degree. C., and wherein said diluent consists essentially of a boric acid ester of certain dihydric alcohols, said dihydric alcohols having Hansen polar (.delta..sub.p) and Hansen hydrogen bonding (.delta..sub.h) cohesion parameters falling within the area of a circle defined as having a center at .delta..sub.h =20.5, .delta..sub.p =13, and a radius of 8.5, to produce a shaped gel of a coploymer of said monomers and said diluent, and (2) thereafter replacing said diluent with water.

Abstract: A method of manufacturing hydrogel dressings from synthetic and natural polymers by polymerization and cross-linking involves pouring aqueous solutions of synthetic polymers, such as polyacrylamide and polyvinylpyrolidone, their monomers or their mixtures, natural polymers, such as gelatine or agar, or their mixtures and, possibly, plasticizing agents, such as poly/ethylene glycol/, poly/propylene glycol/ and silicone oils, of the following composition: 2-20 percent by weight of synthetic polymers, not more than 5 percent by weight of natural polymers, not less than 75 percent by weight of distilled water and 1-3 percent by weight of plasticizing agent, into a mould imparting a shape to the dressing, tightly closing in that mould and subjecting to an ionizing radiation dose not smaller than 25 kGy.

Abstract: A process for producing a porous ceramic filter for use in the filtering of particulates from diesel exhaust gases, and the filter so produced, in which a foamable ceramic composition based upon an aluminosilicate hydrogel binder is expanded into a self-supporting, open-celled porous body of desired shape by virtue of in situ reaction between components of the composition, and thereafter treated to substantially reduce its alkali metal content and fired to produce ceramic bonds, the process further preferably providing on the intended outlet surface of the filter a thin porous ceramic membrane layer whose pores have an average diameter less than that of the pores within and at other surfaces of the ceramic filter.

Abstract: In a process of producing a high-temperature resistant film or a polyimide polymer, a solution of the polymer in an organic solvent is caused to flow out through a slots spinneret of a film forming arrangement and to coagulate in an aqueous precipitation bath containing the organic solvent. The film made up of coagulated liquid is stripped, the organic solvent is removed and the film is dried. In order to attain sufficient strength properties without subsequent orientation and, thus, achieve a better dimensional stability at elevated temperatures, the liquid film formed in the slot spinneret is allowed to fall directly freely into the aqueous precipitation bath through a short air gap. The film formed is drawn off the precipitation bath and is subjected to a subsequent thermal treatment to achieve a transparent homogeneous film. The organic solvent is then removed by treatment with an aqueous extraction agent, and the film is finally dried.

Abstract: A process for forming high free volume, asymmetric gas separation membranes having graded density skins and macrovoid-free morphology from a solvent system comprising a Lewis acid, Lewis base, and a Lewis acid:base complex which dissolve hydrophobic polymers. The dopes have high total solids, high viscosity and low coagulation (g) values which enhance rapid gelation without the formation of macrovoids and which minimize densification. The dope solvent system complexes are readily disassociated by the coagulation medium and the component molecules are miscible in the medium which provides for rapid desolvation of the formed membrane thus providing a membrane having low residual solvent retention.

Abstract: A method for manufacturing carbon fiber strand from an acrylic polymer by steps of (a) wet spinning, (b) washing with water to obtain gelled fiber strand and (c) drying, wherein during the drying step the gelled fiber strand is shrunk by about 5 to 15% when the water of the gelled fiber strand is within a range of from about 100 to 20% by weight based on the weight of the dry fiber strand. An acrylic fiber strand without coalescence or entangling of filaments can consistently be obtained, from which carbon fibers with high quality and substantially no coalescence can be produced.

Abstract: A method of forming material including alternating layers of fibrin and collagen, formed into tubes, is disclosed for use in repairing transected nerve fibers either by tubulization of the approximated nerve ends, or as an artificial graft which are placed in the severed ends of the nerve, for promotion of nerve growth and regeneration. The new material is treated to reduce antigenicity and is resorbed into the body following regeneration of the nerve fibers.

Abstract: A composite self-supporting flexible agglomerated macrostructure is described which includes (1) a matrix of unfibrillated polytetrafluoroethylene resin and addition curable silicone and (2) particulate material including hydroxyapatite and/or tricalcium phosphate uniformly distributed throughout said matrix, the macrostructure being uniformly permeated by a network of open pores formed in the process of manufacture by intimately blending particulate sodium chloride and subsequently leaching the sodium chloride particles.

Abstract: Poly(p-phenyleneterephthalamide) yarn of improved fatigue resistance is prepared by spinning the polymer in sulfuric acid through an air gap into an aqueous coagulating bath to produce a coagulated yarn, maintaining the coagulating bath at a temperature of at least 20.degree. C., washing and neutralizing the yarn while it is under a tension of from 0.2 to 0.4 grams per denier, and drying the yarn at a temperature below 200.degree. C. while it is maintained under a tension of 0.05 to 0.2 grams per denier.

Abstract: The specification discloses a new method and apparatus for treating extruded TEFLON (fluoropolymer) tubing to significantly improve its dimensional and optical characteristics. Diameter tolerance is .+-.0.0002, concentricity rises to 95%, and optical clarity rises to the theoretical transmittance of the material. The tubing is first cleaned, and then heated to a transition temperature above 150.degree. C. to soften and further homogenize the tubing. The tubing is then drawn through a polished diamond die and then rapidly cooled. The cooled tubing may be further stabilized by an annealing step. Both a batch mode and a continuous mode of operation are disclosed.

Abstract: The present invention provides a process for producing a wound dressing delivery system. The wound dressing delivery system is formed by extruding first and second thermoplastic resins onto the surface of a carrier sheet to form first and second thermoplastic films; the first thermoplastic film functions as a temporary support for the second thermoplastic film and the second thermoplastic film functions as a wound dressing and has a moisture vapor transmission rate of greater than 300 grams/square meter/24 hours (ASTM E-96:37.8.degree. C./90% R.H.). The first thermpolastic resin is extruded onto the surface of the carrier sheet and the second thermoplastic resin is extruded onto the surface of the first thermoplastic film such that the first thermoplastic film is interposed between the carrier sheet and the second thermoplastic film.

Abstract: A method of producing a plastic sheet with a porous surface layer suitable for use as, for example, a recording medium on which characters and images are printed by ink jet or thermal-transfer printing method. The method comprises preparing a solution by dissolving two or more kinds of plastics having low levels of miscibility to each other in a solvent, applying said solution to a substrate, passing said substrate with said solution applied thereto through a liquid which dissolves said solvent but does not dissolve said plastics thereby solidifying said plastics, and drying said substrate with the solidified plastic layer. Preferably, two or more kinds of plastics having low levels of miscibility to each other include mainly a material A which is vinyl chloride or its compolymer and a material B which is acrylonitrile or its copolymer.

Abstract: A method for preparing a sustained release formulation utilizing collagen and/or gelatin as a carrier, which comprises the steps:(i) preparing a uniform and high concentrated mixture with respect to the collagen and/or gelatin by blending an active ingredient, said collagen and/or gelatin, and water or an admixture consisting of water and a hydrophilic organic solvent under one of the conditions selected from:(A) the pH of the mixture is kept below 5 and the salt concentration of the mixture is retained below fiber-forming concentration;(B) chemically modified collagen and/or gelatin is employed; and(C) glucose is added to the mixture;(ii) molding the resultant mixture; and(iii) gradually eliminating the solvent from the molded product.

Abstract: A process is provided for preparing high strength polymetaphenylene isophthalamide fibers by the steps which include extruding a dope solution of a metaphenylene isophthalamide polymer in an organic solvent through a spinneret and into a coagulating liquid form in undrawn polymer filament; adjusting the content of the organic solvent; carrying out a first wet drawing in at least one aqueous wet drawing bath; making a second adjustment of the content of the organic solvent; carrying out a second wet drawing at a specified draw ratio in at least one aqueous wet drawing bath; drying the second wet drawn filament; and dry drawing the dried filament.

Abstract: A porous regenerated cellulose hollow fiber is obtained by a micro-phase-separation method. The hollow fiber is characterized in that the viscosity average molecular weight is at least 5.times.10.sup.4, each of the average pore diameter D.sub.1 on the inner wall surface of the hollow fiber and the average pore diameter D.sub.2 on the outer wall surface is 0.02 to 10 .mu.m, the in-plane porosity Pr on the outer wall surface is at least 10%, and the hollow fiber comprises a wall thickness portion having pores piercing therethrough between the inner wall surface and outer wall surface and a hollow portion extending continuously over the entire fiber length.

Abstract: There is provided a method of removing binding material from a shaped preform (green body) in the preparation procedure for the manufacture of ceramics from particulate materials by a new method comprising exposing the green body to a liquidified fluid to dissolve the binder materials in a liquidified fluid without deformation of the shape of the article. In the method, the binder materials can be removed without swelling of the article because the green body is not exposed to a rapid temperature increase and the binder does not volatilize in the body. Further the binder material can be removed in a shorter period of time from the entire body.

Abstract: Hydrophilic polyacrylonitrile filaments or fibres where at least one filament-forming synthetic polymer is wet spun in a spinning solvent and wherein the spinning solvent has added to it from 10 to 20% by weight of a substance which is readily miscible with the spinning solvent and a washing liquid and is a nonsolvent for the polymer to be spun.

Abstract: Non-flammable, high-temperature resistant polyimide fibers have irregularly lobed or serrated cross-sections, a wool-like smooth hand and high brightness. They are produced by a dry-spinning process which is carried out in a spinning column, wherein a 20 to 40% solution of the polyimide is spun from spinnerets having circular orifices, the orifice numbers ranging from 20 to 800 and the orifice diameters from 100 to 300 .mu.m. An extrusion speed of between 20 and 100 m/min, a take-up speed of between 100 and 800 m/min, an amount of spin gas between 40 and 100 m.sup.3 /h under standard conditions and a spin gas temperature of between 200.degree. and 350.degree. C. are applied. The tows leaving the spinning column, which contain residual solvent from 5 to 25% by weight--based on dry polymer--and have a single filament titer of between 3.

Abstract: A process for preparing improved pellets of a hydrolyzed ethylene-vinyl acetate copolymer which comprises extruding a methanol or a water-methanol solution including a hydrolyzed ethylene-vinyl acetate copolymer and a lubricant into a coagulating liquid in the form of a strand and cutting the strand into pellets. According to the process of the present invention, the molding processability can be improved without damaging the properties of the molded articles.

Abstract: A method for eliminating a dispersion medium from a molded product obtained by plasticizing-molding or casting-molding one or more of metallic and ceramic powders, wherein the elimination process is carried out in a supercritical liquid carbon dioxide atmosphere without heating to higher temperatures.

Abstract: An acrylic fiber precursor for high performance carbon fibers free of defects which comprises an acrylonitrile polymer containing at least 90% by weight of acrylonitrile and has a surface roughness of 2.0 to 3.0 with dense inner structure. from a solution comprising 24 to 27.5% of the acrylonitrile polymer is dry-jet wet spun into a coagulation bath consisting essentially of dimethylformamide or dimethylacetamide and having a bath temperature of 5.degree. to 25.degree. C.Carbon fibers obtained by carbonizing these precursor acrylic fibers have no fusion bonding or agglutination of filaments and exhibit high performance.

Abstract: Packaged fibrous and non-fibrous reinforced food casings containing sufficient water that presoaking prior to stuffing can be eliminated. The casings which rely on water as the sole or principal plasticizer do not rely on chemical type plasticizers like glycerin and propylene glycol. The premoisturized, ready-to-stuff casings are preserved with effective amounts of a high pH active antimycotic agent. Drying requirements can be reduced or eliminated.

Abstract: A process for preparing collagen membranes useful in tissue repair, and wound healing and related membranous implant materials useful in both hard and soft tissue applications is disclosed. The resulting membranes and materials have properties which can be varied as desired to suit intended use. Variation results from altering the precise conditions of formation of the membrane or of related fibers and solids. The process comprises first forming a gel from solubilized collagen, followed by converting the gel into a one-, two- or three-dimensional membranous solid form. This conversion is performed either by applying pressure to the gel, or by disrupting the gel and separating the resulting precipitate for casting.

Abstract: A method of producing abrasive fibers is disclosed, which comprises providing a conjugate fiber comprising at least one abrasive layer containing abrasive particles and at least one coating layer substantially covering the abrasive layer, and removing at least a part of the coating layer from the conjugate fiber with a solvent or a decomposer to expose at least a part of the abrasive layer from the coating layer.

Abstract: Polyacrylonitrile filaments and fibers may be obtained without interruption by spinning the spinning solution into a hot-air spinning duct, washing, drawing, crimping, preparing, steaming, drying cooling and, optionally, cutting at a take-off rate kept at 150 to 400 m/minute and for a tow weight of from 10 to 100 g/m when(a) the washing process is carried out in several stages on the countercurrent principle and a vibrating duct is used for transporting the spun tow through the washing process,(b) drawing is carried out before and/or after washing in a steam atmosphere at 100.degree. to 120.degree. C.,(c) crimping is carried out in an aerodynamic crimping unit using a hot, gaseous medium under a pressure of from 5 to 16 bars and at a temperature in the range from 50.degree. to 210.degree. C.

Abstract: A process of making a wound dressing is suggested, in which a technical conventional viscose solution is mixed with a polysaccharide derivative; the mixture is treated at increased temperatures such that it is thermally coagulated; the coagulate is wetted with a polyalkylene glycol and dried, whereby a particulate structure of the wound dressing is produced.

Abstract: Method for increasing the absorbency of cellulosic fibers by a high temperature wet treatment comprising heating the fibers in a water bath at temperatures within the range of about 95.degree. C. to 100.degree. C. for periods ranging from about one to sixty minutes. Absorbency of the treated fibers is thus increased by more than 2% of the corresponding untreated fibers as measured by the Syngyna Test Method. By employing such materials in catamenial tampons, sanitary napkins or the like, the amount of absorbent material may be decreased by 10% or more relative to the corresponding, untreated absorbent material, without adversely affecting the absorbent characteristics thereof.

Abstract: Hot pressed refractory boride shapes are treated with molten alkali metal hydroxide such as by immersion in a bath of the molten hydroxide. The treatment cleans and removes residual carbon from the surface layer of the shapes.

Abstract: A flexible, air permeable composite highly effective as a highly absorbent fiber filter, suitable for high throughput, low pressure drop applications. The composites and filters use a non-woven fabric substrate, in conjunction with organic polymer fibers, such as polypropylene fibers, formed in-situ from a solvent solution of the polymer, with solid particles such as carbon particles interstitially positioned within the mass, and forming a unique microstructure by the interaction of the flexible non-woven fibers and the polymer fibers. A method of entrapping small sorptive particles within such filters is also provided.

Abstract: A process for making an encapsulated metal oxide varistor package comprises pressing the varistor powder mixture into a disc, sintering the pressed disc, followed by slow cooling to room temperature.The sintered disc is acid etched and a fritted-silver electrode applied on each side of the disc or in the alternative an aluminum coating is arc sprayed on each side of the disk followed by an arc sprayed copper coating on top of the aluminum coating. The fritted-silver electrode coating is heated to 660.degree. C. and slow cooled to room temperature. Sn-coated copper leads are soldered on the electroded disc of either electrode process and the assembly is encapsulated in resilient epoxy resin to form the encapsulated metal oxide varistor package.

Abstract: A method for making curved hose using a curved mandrel by applying a melted material to an inside surface of an uncured hose and solidifying the material. The material is remeltable and forms a lubricant when the hose is pushed onto and removed from a hot curved mandrel.

Abstract: A process for making relatively thick foraminous members the foramina of which form a preselected pattern. The backing film such as a thermoplastic film is placed in contact with a rotating drum. A foraminous woven element about which the foraminous member will be constructed is placed in contact with the thermoplastic backing film. Liquid photosensitive resin is supplied to a controlled thickness. A mask comprising the preselected pattern is placed adjacent the photosensitive resin and the resin is exposed through the mask to the light of an activating wavelength. Uncured resin is washed from the composite leaving behind the completed foraminous member.

Abstract: A film of poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl]-1,4-phenylene}, its cis isomer or mixtures thereof is formed by extruding a solution of the polymer on a casting roll which is rotating to yield a surface speed slightly greater than the rate of extrusion. The solution of the polymer may be prepared by dissolving the polymer in an appropriate solvent or by reacting the monomers in a selected reaction medium. The cast film is washed, subjected to an elevated temperature, preferably heat treated under tension, and recovered.

Abstract: A hot roll, for use in a xerographic hot roll fuser, is made by coating a hollow aluminum cylinder with an elastomer, as by the use of an injection molding machine. After molding, the external surface of the elastomer cylinder is ground slightly to improve its concentricity. Thereafter, this ground external surface is subjected to the chemical influence of an acid. After a predetermined time period, the acid treatment is terminated and the roll is washed in water. The resulting hot roll, whose external surface has been chemically modified, possesses improved dry-release properties.

Abstract: A method of making a building panel comprises the steps of (i) casting a first or inner layer of reinforced concrete which has an obverse face and a smooth reverse face; casting a second or outer, ribbed layer of reinforced concrete which has an obverse face and a smooth reverse face; placing the first and second layers adjacent one another with the two obverse faces directed inwardly towards one another; and providing a layer of thermal insulation material between the two obverse faces. By this method a panel can be provided of which the faces are both smooth.

Abstract: Video discs are cleaned with a water-based solution to remove water soluble salts from the surface of the discs, thereby reducing the moisture sensitivity of the discs.

Abstract: The starting materials for the practice of the present invention are (1) one or more organic monomers or oligomers which upon irradiation very rapidly undergo a polymerization reaction to form a solid polymer; and (2) a liquid vehicle in which the one or more organic monomers or oligomers are soluble but in which the polymer formed is insoluble. For the manufacture of microporous membrane in accordance with the invention the monomers or oligomers are dissolved in the liquid vehicle, the resulting solution is formed into a thin layer, and the thin layer of the solution is then irradiated as with ultraviolet or electron beam radiation whereupon the rapid polymerization reaction immediately ensues and the polymer formed immediately segregates from the vehicle thereby resulting in microporous membrane from which the vehicle can be removed as by evaporation or washing.

Abstract: Non-fused hollow glass microspheres that consist primarily of silicate are rendered more water-resistant by treatment with multivalent metals. The hollow microspheres are slurried with water and then a solution of a multivalent metal salt such as Al.sub.2 (SO.sub.4).sub.3 is added to the slurry. The rate of the addition is controlled so that the pH can be regulated. Separating, washing and drying complete the preparation.

Abstract: High density information discs, such as video discs, which have been treated with an ammonium salt become resistant to and stable under conditions of high relative humidity, even after repeated exposure to such conditions for extended periods of time. The treatment with the ammonium salt is accomplished by use of a bath of an aqueous solution of the ammonium salt, with the preferred ammonium salt being ammonium chloride.

Abstract: A basin for simultaneous or consecutive dewaxing and curing of denture molds is disclosed. The basin is generally box-shaped and is provided with three vertically-shaped trays of which the topmost remains above the high fluid level. The upper rear portion of the basin has a pivotally-secured frame-arm provided with a plurality of nozzles adapted to spray over the entire area of the topmost tray. The fluid from the nozzles drains back into the basin; a recirculating pump recirculates the fluid back into the nozzles. A separate fluid inlet is provided to fill the basin for curing. The basin is further provided with an upper and lower fluid level-limiting means, a heating element, a thermostat and, preferably, an automatic timer.

Abstract: Process for the continuous production of viscose rayon yarns having a high egree of whiteness, comprising extruding a viscose solution into a coagulating bath, drawing and coagulating the extruded filaments, advancing said filaments in a substantially helical path while they undergo all the treatments required for the production of the finished yarn, which process is characterized by, after the exit of the filaments from the spinning bath, completion of the coagulation to a coagulation index not higher than 1 and a treatment with water having a non-alkaline pH.

Abstract: Salt is recovered in a molten state from wash water used to wash extruded rubber parts. The parts, before washing, are coated with salt because they are cured in a molten salt bath. The molten salt recovered from the wash water was fed back into the carrying tank, thus eliminating salt loss and temperature change of the tank's molten salt content.

Abstract: A viscose rayon filament yarn excellent in resistance to deterioration with time and uniform in boiling water shrinkage factor in the longitudinal direction of yarn which has been produced by a continuous spinning process characterized by spinning a viscose having a sulfur content of sulfur oxides and polysulfides of 0.55% by weight or less based on the weight of cellulose, then allowing the yarn to stand for a time period defined by the following equation and then washing it with water and drying it:7.5D.sub.M +15.ltoreq.T.sub.s .ltoreq.10D.sub.M +25wherein D.sub.M is denier of the monofilament constituting the rayon filament yarn to be spun and T.sub.s, expressed in second, is the standing time of the viscose filament spun.

Abstract: Video discs are dried by first spraying the surface with liquid fluorocarbon to remove water and heating the disc so as to prevent water condensation during evaporation of the fluorocarbon, preferably in a fluorocarbon vapor.

Abstract: Film of a wholly aromatic polyamide, at least 85% of the repeating units of which are meta-phenylene isophthalamide units, which is undrawn and noncrystalline and which has improved impact strength. Such film is made by heat-treating film of the polyamide which is undrawn and noncrystalline at 400.degree. to 300.degree. C. for from 2 seconds to 2 minutes while maintaining the film at constant length and width permitting it to shrink by at most 20% in each of the length and width.

Abstract: High density information discs, such as video discs, which have been treated with a fluorinating agent become resistant to and stable under conditions of high temperature and high relative humidity, even after exposure to such conditions for extended periods of time. The treatment with the fluorinating agent is accomplished by use of a bath of an aqueous solution of a "soft" fluorinating reagent, such as fluorosilicic acid or fluoroboric acid.

Abstract: An equilibrium melt from a standard hydrolytic or anionic polymerization of caprolactam is spun at a temperature between about 230.degree. and 270.degree. C. through a spinnerette, preferably one having a multiplicity of holes spaced from each other in an asymmetric arrangement, the spinning take-away speed being less than about 250 meters/minute. The molten strands of polycaprolactam are quenched in two phases: (1) gas at a temperature of less than 20.degree. C. is directed from a first entrance in a crosscurrent flow upon the face of the spinnerette and upon the molten polycaprolactam strands immediately adjacent thereto, and is exhausted adjacent to the back of the spinnerette; and (2) gas at a temperature of less than 20.degree. C. is directed in a countercurrent flow from a second entrance downstream from the first entrance with respect to the direction of movement of the polycaprolactam strands; whereby the surface temperature of the polycaprolactam strands is reduced to 30.degree.-70.degree. C.

Abstract: High density information discs that have been compression molded from a conductive carbon-containing polyvinylchloride molding composition are cleaned with a water based solution to remove water soluble salts from the surface of the disc, followed by a high temperature aqueous wash wherein the temperature is from about 110.degree. to about 130.degree. F. These discs have improved environmental stability.

Abstract: A novel method is proposed for improving the surface properties or, in particular, for increasing the affinity to water of and for reducing accumulation of static electricity on the surface of a shaped article made of an acrylic resin. The inventive method comprises first exposing the surface of the shaped article to low temperature plasma of a gas having no polymerizability in plasma and then bringing the plasma-treated surface into contact with an aqueous solution containing a surface active agent. The effect of the inventive method is so strong and durable that the treated surface remains antistatic even 6 months after the treatment.

Abstract: An outer mold part is positionable over an inner mold part. Lever means are carried on opposite sides of the outer mold part and operable by a lifting force to exert a separating force between the outer and inner mold parts. Lever means are carried by the outer mold parts for locking the molded article to it. The outer mold part and the molded article are lifted upwardly together as an assembly and are removed entirely from the inner mold part. The assembly is then set down, the outer mold part is unlocked from the molded article, the outer mold part is then picked up and removed from the molded article, and then the bottom is poured in and is connected to the molded article.