Abstract: A process for making powder-free medical gloves that are nevertheless easy to don involves first forming a glove on a form by successively dip-coating layers of a coagulant containing acid-soluble powder dispersed throughout, an elastomer, and an antiblocking composition with particles distributed throughout. After curing the elastomer and applying a silicone coating, the glove is removed from the form and treated successively with acid, to dissolve the powder, and with bleach, to reduce blocking. Using this process, high quality natural rubber medical gloves can be produced.

Abstract: A method for producing intaglio designs in cast acrylic material, wherein a moulding tool hotter than 600.degree. C. is applied to a surface contact area of an acrylic surface in which the intaglio copy of the moulding tool is to be formed, and the moulding tool is withdrawn from the surface contact area before the temperature of the tool or the acrylic material of said area falls below that at which methyl methacrylate vapor ceases to be produced by the depolymerization of the acrylic material. The preferred withdrawal temperature is above 250.degree. C.

Abstract: Improved polybenzoxazole fibers are made by a process for finishing a spun and drawn dope fiber, which contains polybenzoxazole polymer and a solvent acid, including the steps of: (a) coagulating the dope fiber in an aqueous coagulant: (b) washing the coagulated fiber with an aqueous washing fluid for less than 72 hours under conditions such that the fiber contains no more than 8,000 ppm residual solvent acid (1 ppm=1 part per million, by weight); (c) drying the fiber at a temperature of no more than 300.degree. C. until it retains no more than about 2 weight percent residual moisture; and (d) heat-treating the fiber at a temperature of at least about 300.degree. C. under tension.

Abstract: An aromatic sulfide/ketone polymer is prepared from a dihaloaromatic ketone, alkali metal sulfide, water and a polar organic compound. The polymerization reaction mixture is subjected to a heat soak at an elevated temperature, then a separation agent is added under controlled conditions and the mixture is subsequently cooled to provide a mixture comprising particulate aromatic sulfide/ketone polymer. Biaxially-oriented film is made from the recovered particles of aromatic sulfide/ketone polymer by (1) washing the polymer particles with an aqueous calcium salt, (2) heating the washed particles to remove water, (3) molding the heated particles to form a sheet of polymer, (4) biaxially stretching the sheet above the glass transition temperature of the polymer to form a film, and (5) heat-setting the biaxially-oriented film under stretching tension for a time and at a temperature to increase strength properties and density.

Abstract: The present invention relates to the efficient removal of low density lipoprotein cholesterol complex (LDL-C) from whole blood. More specifically, it relates to a process for making a microporous plasmapheresis membrane having an immobilized affinity agent. The immobilized affinity agent is polyacrylic acid bound directly and/or through an interaction with silica and/or calcium chloride to a microporous hollow fiber membrane.

Abstract: This invention relates to novel processes for preparing polypeptide solutions and spinning them into fibers. The process involves dissolving a polypeptide in a solvent system comprising lithium thiocyanate (LiSCN) and a liquefied phenol selected from the group consisting of phenol, m-chlorophenol, m-fluorophenol, and m-bromophenol or mixtures thereof. The solutions may be spun using certain wet spinning and dry-jet wet spinning methods. The process is especially useful for making silk fibroin fibers.

Abstract: An improved stereolithographic apparatus and method is described. In one embodiment, the improvement includes immersing at least a portion of a part in a volume of a liquid solvent in a vapor degreaser while subjecting the portion to ultrasonic agitation to substantially remove excess resin. Several examples of solvents are provided, including ethanol, and Freon TMS. In a second embodiment, the improvement includes building the part on a layer of liquid resin supported by a volume of a dense, immiscible, and UV transparent intermediate liquid, and integratably immersing at least a portion of the built part in the intermediate liquid, and then either subjecting the immersed portion to ultrasonic agitation to substantially remove excess resin, or subjecting the immersed portion to UV light. Several examples of intermediate liquids are provided, including perfluorinated fluids, such as Fluorinert FC-40, and water-based salt solutions, such as solutions of magnesium sulfate or sodium chloride in water.

Abstract: An improved method for lining a section of pipe with a cement mortar. After a wet cement mortar has been applied to a cleaned interior surface of a pipe, carbon dioxide is introduced into the freshly lined section of the pipe in such quantity that a crust of calcium carbonate will be formed on the surface of the wet cement mortar lining as the carbon dioxide reacts with calcium compounds of the wet cement mortar in a relatively short period of time. This crust is provided to tolerate a low-velocity flow of water to protect the underlying mortar from scouring until the normal hardening of the underlying mortar through hydration can take place so as to substantially reduce the out-of-service time of the section of pipe which is being lined.

Abstract: A roller vacuum apparatus removes cement slurry from a freshly laid exposed aggregate surface. In one embodiment, the exposed aggregate surface is applied to a cement substrate which is worked to compact the aggregate and draw the portland cement in the mixture to the surface of the coating. Subsequently, the surface coating is washed to remove excess portland cement. The roller vacuum removes the cement slurry without disturbing the freshly laid exposed aggregate surface by wicking the slurry into a transfer medium of the vacuum roller. A vacuum is applied to the transfer medium to remove the cement slurry from the roller.

Abstract: More uniform and more rapid quenching and coagulation of filaments is achieved by contacting the filaments in a chamber with coagulating liquid and generating pressure fluctuations in the liquid at high frequency sonic or ultrasonic frequencies.

Abstract: The present invention relates to the efficient removal of low density lipoprotein cholesterol complex (LDL-C) from whole blood. More specifically, it relates to the use of an immobilized affinity agent on a microporous plasmapheresis membrane. The immobilized affinity agent is polyacrylic acid bound directly and/or through an interaction with silica and/or calcium chloride to a microporous hollow fiber membrane.

Abstract: An acrylic fiber tow which includes 1) monocomponent filaments of each of two acrylonitrile polymers differing in hydrophilic properties, 2) bicomponent filaments of both of said polymers having one interface between polymers components and 3) bicomponent filaments of both of said polymers having more than one interface between polymer components. This fiber, however, in spite of its composition of numerous filaments of differing structure provides a tow bundle having a desirable level of reversible crimp measured in a manner specific to the type of crimp designated.

Abstract: A method for making a separator material which is useful as a separator for storage batteries. The method involves applying a sulfonated surface layer to polyolefin resin fibers which form a woven or non-woven fabric. According to one embodiment, polyolefin resin fibers made of a first polyolefin resin are coated with a surface layer of a second polyolefin resin which is more susceptible to sulfonation than the first polyolefin resin from which said fibers are made. At the stage when the polyolefin fibers are coated with the second polyolefin resin they may be either individual fibers or formed into a woven or non-woven fabric. Thereafter, the fibers are subjected to a sulfonation process until the surface layer is sulfonated and a decomposition product formed by the sulfonation process is then removed from the fibers to obtain a separator material.

Abstract: A process for the surface treatment of moldings based on polyamides by treatment with an aqueous acid, wherein the aqueous acid used is a 30-85% strength solution of H.sub.3 PO.sub.4 yields moldings which are readily metallizable. Metallized moldings obtained by this process are useful in the production of automobiles and in the electronics industry.

Abstract: Fiber made from PPD-T with 0.5 to 3.0% sulfur as bound sulfonic acid or sulfonate groups, is disclosed. The fiber has inherent viscosity greater than 4.5, yarn tenacity greater than 20 grams per denier, heat-aged strength retention of greater than 90%, and dipped cord strength greater than 18 gram per denier. The process for making the fiber includes PPD-T sulfonation by exposure to high concentration sulfuric acid in dope preparation under carefully controlled temperature and time.

Abstract: A process for spinning para-aramid fibers of increased tenacity and elongation at break by using an air-gap means with a spinneret capillary of less than 2.5 mils diameter, a coagulation bath temperature of less than 10C, and tension on the fibers during washing and drying of more than 0.05 and less than 0.35 gpd.

Abstract: Styrene-based polymer moldings and a process for efficient production thereof are disclosed. The styrene-based polymer moldings are obtained by subjecting moldings of styrene-based polymers with mainly syndiotactic configuration and a weight average molecular weight of at least 100,000 to solvent treatment, such as, by dipping in a solvent or exposing to a solvent vapor. The styrene-based moldings are excellent in gas permeability and heat resistance, and thus are useful as gas permeable membranes, vegetable wrapping films or moldings required to have good heat resistance.

Abstract: A process for treating a container having a normally solid, polymer surface with a sulfur-containing compound is carried out in two stages. In the first stage, a first sulfonation treatment is conducted by: (i) contacting the surface at a temperature of about 115.degree. to about 140.degree. F. with a first sulfur-containing compound; and, (ii) washing the surface with an aqueous liquid. Optionally, in the first stage, after the surface is contacted with the first sulfur-containing compound, but before it is washed with the aqueous liquid, the surface may be contacted with a first neutralizing agent. In the second stage, a second sulfonation treatment is conducted by contacting the surface with a second sulfur-containing compound, a second neutralizing agent and washing the surface with an aqueous liquid. The second sulfur-containing compound and the second neutralizing agent may be the same as or different than the first sulfur-containing compound and the optional first neutralizing agent, respectively.

Abstract: Water-dispersible polyester fiber whose water-dispersibility is improved, and precursor filament tow are prepared by an improved process involving treatment of undrawn polyester filaments with a very small amount of caustic, when freshly-extruded, in a spin-finish.

Abstract: An improved stereolithographic apparatus and method is described. In one embodiment, the improvement includes immersing at least a portion of a part in a volume of a liquid solvent in a vapor degreaser while subjecting the portion to ultrasonic agitation to substantially remove excess resin. Several examples of solvents are provided, including ethanol, and Freon TMS. In a second embodiment, the improvement includes building the part on a layer of liquid resin supported by a volume of a dense, immiscible, and UV transparent intermediate liquid, and integratably immersing at least a portion of the built part in the intermediate liquid, and then either subjecting the immersed portion to ultrasonic agitation to substantially remove excess resin, or subjecting the immersed portion to UV light. Several examples of intermediate liquids are provided, including perfluorinated fluids, such as Fluorinert FC-40, and water-based salt solutions, such as solutions of magnesium sulfate or sodium chloride in water.

Abstract: A process for making fibers of para-aramid and poly(vinyl pyrrolidone) (PVP) comprising agitating a mixture of solvent acid, para-aramid, and PVP, heating the mixture to form a solution, extruding the solution, drawing the extruded solution, passing the stretched solution through an aqueous coagulating bath to form filaments and washing the filaments.

Abstract: The process for production of polyacrylonitrile hollow threads with a stable, asymmetric pore structure by a dry-wet-spinning process with glycerine-based core liquids, definite draw and after treatment conditions and a treatment with alcohols and drying.

Abstract: A method of making a collagen-hydrogel is shown. The method comprises the steps of forming a radical free polymer of a hydrophilic monomer; mixing the hydrophilic monomer with a stock solution of collagen in the presence of a weak solution of ammonium persulfate and sodium metabisuleate forming a clear viscous monomer solution; and heating said viscous monomer solution in the presence of a crosslinking agent to polymerize the same into a three dimensional polymeric meshwork having collagen from the stock solution of collagen interdispersed within the three dimensional polymeric meshwork.

Abstract: A method for producing para-aramid pulp by using gravity-induced orientation of anisotropic para-aramid solutions. The solutions are those in which the para-aramid is still actively polymerizing. The process can be practiced on immobile inclined supports or on a moving inclined support in the form of a conveyer.

Abstract: Foam rubber articles may be prepared by shaping foamed latex into the desired configuration and gelling it. The gelled latex may then be cut to the required thickness to provide articles such as cosmetic puffs. The shaping process may use a disposable mold such as a circular polymeric casting or the mold may be permanent, such as glass, passing through a gelling chamber. The process reduces waste for products which has previously been cut from slab foam.

Abstract: A wet and dry jet wet spinning process produce one or a plurality of siliceous-containing fibers. At least a partial hydrolyzate is formed from silicon alkoxides and/or colloidal dispersions of hydrolyzable metal oxides through acid catalyzed hydrolysis in the presence of a solvent. The ratio of amounts of the water to silicon alkoxide or hydrous oxide is around 1.5 to 1 up to less than around 4 to 1. Both the hydrolysis and polymerization reactions produce an ungelled hydrolyzate with a viscosity in the range of 70 to greater than 1000 poise. This hydrolyzate is extruded through a spinnerette into a gaseous environment for dry jet wet spinning followed by contacting with a nonsolvent liquid or directly into a nonsolvent liquid for wet spinning. The contacting with the nonsolvent liquid is for effective coagulation to produce cohesive fiber that may have some stickiness. The fiber is removed from the nonsolvent liquid where the fiber's length is continuous from the spinnerette to removal.

Abstract: A process for the production of a porous organic material, in particular a semi-permeable membrane, comprising a plurality of separate passageways, including dissolving a polymer in a solvent, using a drawplate having needles of a shape conjugate with those of the passageways and of external dimensions between 0.7 and 1.2 times those of the passageways and an extrusion orifice of a shape conjugate those of the extrudate and of internal dimensions comprising between 0.8 and 1.2 times those of the extrudate, injecting around the needles a solution having a viscosity greater than 500 mPa.s and introducing a centering fluid into the interior of these needles, recovering the extrudate at the output of the drawplate in a precipitating medium in such a manner that the extrudate travels in the medium a distance such that 800.times.

Abstract: Drawn polyester multi-filament yarns, preferably prepared by a coupled process of spin-drawing, and of fabrics and garments thereof, are prepared by an improved process involving treatment of freshly-extruded polyester filaments with caustic in the spin-finish, so as to improve moisture-wicking properties.

Abstract: Polyester crystalline filaments that have been prepared by spin-orientation, and filaments prepared by drawing such filaments without texturing, in yarns thereof, and in fabrics and garments thereof, are prepared by an improved process involving treatment of freshly-extruded polyester filaments with caustic in the spin-finish, so as to improve moisture-wicking properties.

Abstract: Aromatic/Aliphatic copolyamides are recovered from lactam-plasticized polymer then melted and extruded to form shaped structures.

Abstract: A method of producing a nonlinear optical film from a lyotropic liquid crystalline polymer by diluting the polymer with a dopant to form a concentrated mixture. The concentrated mixture is filtered in a high pressure filtration cell and vacuum degassed. Thin film are formed on plates and are coagulated in water. The thin films are supported on a microporous membrane support and then air dried.

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, an alkyl (meth)acrylate wherein the alkyl group contains at least four carbon atoms, 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 (w.sub.p) and Hansen hydrogen bonding (w.sub.h) cohesion parameters falling within the area of a circle defined as having a center at w.sub.h =20.5, w.sub.p =13, and a radius of 8.5, to produce a shaped gel of a copolymer of said monomers and said diluent, and (2) thereafter replacing said diluent with water.

Abstract: Process for making aromatic polyamide fibers of high hydrolytic stability is disclosed. The polyamide is a copolymer including chloroterephthalamide or a blend of homopolymers including one with chloroterephthalamide; and the fibers are dried under tension or heat treated.

Abstract: A process for the discontinuous or (preferably) continuous production of dry spun hydrophilic acrylic fibers and threads with a core/sheath structure which have improved color fastness properties, more uniform cross-sections and better processing characteristics. By employing a new after-treatment combination of more intensive counterflow washing, stretching in steam, fixing in steam and careful drying of the fibers as staple fibers, improved hydrophilic fibers with a water retention capacity above 30% can be obtained from spinning solutions which have a much lower non-solvent content than is necessary in the present-state of the art for obtaining a high water retention capacity of the order indicated above.

Abstract: A process is disclosed for preparing high tenacity, high modulus, para-aramid fibers by application of cyclic tensioning forces to such fibers in the newly-spun, wet, state before they have been dried.

Abstract: A method for casting a metal or ceramic powder which comprises casting a slurry of the metal or ceramic powder suspended in a dispersion medium containing at least 10 wt. % of a liquid extractable with a supercritical fluid or a liquefied gas into a porous mold, keeping the slurry placed in the porous mold at a temperature not lower than the melting point of the dispersion medium, and extracting at least 10 wt. % of the dispersion medium with the supercritical fluid or liquefied gas to impart a formability to the extracted body.In the method of the invention, since the volume change of the dispersion medium due to phase change does not occur, the internal strain and deformation of the molded body occur little. As a result, the sintered body obtained has a highly dimensional accuracy.

Abstract: A dope for forming membranes and the resulting asymmetric gas separation membranes are disclosed, the membranes having graded density skins which exhibit improved permeability characteristics and increased failure pressure strength. The membranes are produced from a process utilizing membrane forming dopes of complexing solvent systems formulated from two non-solvents and one or more solvents. The non-solvents are chosen one each, from non-solvents grouped according to non-solvent strength, i.e., one strong non-solvent and one weak non-solvent which are combined with one or more solvents in an acid:base complex solvent system for dissolving high weight percent total solids of membrane forming polymers. The process for forming the membranes is also disclosed.

Abstract: A process for preparing high modulus, high tenacity fibers of aromatic polyamide wherein a first constant tension within 40-95% of the fiber breaking load is applied to washed fibers at a temperature of less than 50.degree. C. for a duration of greater than 5 seconds, and drying the fibers at a second constant tension which is from 10-100% of the first constant tension and at a temperature of more than the temperature of the first constant tension and less than 350.degree. C. until the fibers have a moisture content of about 2 to 10%.

Abstract: This invention relates in general to the formation of thick films having a biaxial molecular orientation. Such films are prepared in accordance with the present invention from rod-like extended chain aromatic-heterocyclic ordered polymers. Such films have high tensile strength, modulus, and environmental resistance characteristics. A preferred ordered polymer for use in the present invention is poly (para--phenylenebenzo bisthiazole), (PBT), a compound having the structure: ##STR1## The present invention is also directed to methods and apparatus suitable for producing biaxially oriented films, coatings, and like materials from ordered polymers, preferably PBT.

Abstract: A process for applying a permanent filled engraved identification to the surface of an object such as a paving brick which is made of porous material.

Abstract: A printed circuit is formed by conventional methods over an adhesive coating applied to a flexible high temperature withstandability disposable backing to form a flexible laminate which is positioned in a cavity of an injection mold to conform to surface variations. The printed circuit conductors are surrounded on three sides by molten plastic material injected into the mold cavity to embed the conductors in the respective surfaces of the molded plastic article, which surfaces are non-coplanar and adjoining and the conductors are continuous from one surface to the other. The bond strength of the adhesive is preferably high with regard to the backing and low with regard to the printed circuit conductors to permit adhesive and backing to be peeled away after molding, thereby providing a three diemensional printed circuit in, for example, a recessed area of a molded plastic housing part of electrical apparatus.

Abstract: There is disclosed a method for eliminating an organic dispersion medium from a molded product obtained by plasticizing-molding or casting-molding of metallic and/or ceramic powders wherein the elimination is by extraction by liquid carbon dioxide at a temperature not lower than -30.degree. C. and not higher than -31.1.degree. C. The method prevents nonuniform volumetric decrease of the molded product to be otherwise caused by the extraction of the organic dispersion medium, while also making it possible to completely eliminate the organic dispersion medium without causing residual strain or deformation in the molded product.

Abstract: In a method of manufacturing carbon fiber with less uniformity of physical strength in the longitudinal direction, an oil additive in a volatile medium is applied to an organic fiber after it is removed from a container and while the volatile medium has not completely evaporated from the fiber, and before the fiber is fed to a flameproofing furnace.

Abstract: A carbon fiber of high strength is disclosed, each filament of which is substantially circular in its cross-section but which has circumferential ruggedness which extends in parallel to an axis of the filament to form pleats. The ruggedness has a depth of more than 0.1 .mu.m.The carbon fiber is prepared by extruding a spinning solution of an aqueous polyacrylonitrile/pure zinc chloride solution of a specified polymer content into a coagulating bath at a specified draft ratio, followed by washing, drying and stretching at a total stretching ratio of 10-20 folds to form a precursor which is then subjected to conventional stabilizing and carbonizing steps.

Abstract: The invention relates to a process for making porous carbon membranes and membranes which can made by this process. As starting material, a porous membrane from an acrylonitril-polymer is used. The starting material is pretreated with a hydrazine solution, followed by preoxidation and carbonization. The process enables carbon membranes to be made with selectively adjusted pore sizes and tight pore size distribution. The pore sizes can lie in the ultrafiltration or microfiltration range. The membranes are suitable for separation processes, in which chemically aggressive media are used and for high-temperature processes. They can be used wherever electrical conductivity of the membranes is required.

Abstract: A method of making a concrete block having decorative stones embedded in a surface thereof includes the steps of placing on a face plate a layer of stones which includes a plurality of spaced decorative surface stones and includes filler stones substantially smaller than the surface stones and disposed in the spaces between the surface stones, applying a cement mortar on the surface stones and filler stones, introducing concrete into a separate mold, inverting the face plate and placing it on top of the concrete in the mold, consolidating the concrete and assembling the concrete and the sruface stones by applying pressure and vibration, removing the mold and the face plate, and curing the resulting block without the mold.

Abstract: An improvement in the conventional wet-spinning process for producing acrylic fibers increases the spinning performance and/or productivity of the process and comprises imparting a plurality of stretches to the fibers as they are being dried on the heat rolls of the drying train employed in the process.

Abstract: A process to produce oriented, crystalline polyaniline films using simultaneous heat treatment and stressing of polyaniline films. Films stressed while being held at elevated temperatures (T.gtoreq.110.degree. C.), showed anisotropic x-ray, IR and visible optical response.

Abstract: An asymmetric microporous hollow fiber for hemodialysis is made up of 90 to 99% by weight of a first hydrophobic polymer and 10 to 1% by weight of a second hydrophilic polymer. The fiber has a water adsorbing capacity of 3 to 10% and is produced by extruding a solution containing 12 to 20% by weight of the first polymer and 2 to 10% by weight of the second polymer, the rest being a solvent to give a continuous hollow structure with a wall, causing a precipitation liquor to act on said structure in an outward direction through the wall thereof with the full precipitation thereof and the concurrent dissolution and washing out of a part of said first polymer from said extruded structure and then washing out the dissolved out part of the pore-forming substance and the other organic components. Thereafter the fiber so produced is fixed in a washing bath.

Abstract: A process is disclosed for the production of biaxially oriented liquid crystal films. The process includes:(i) forming an anisotropic dope from a polymerization solution of rigid rod heterocyclic liquid crystalline polymers such as poly{[benzo(1,2-d:4,5-d')bisthiazole-2,6-diyl] 1,4-phenylene}, its cis isomer or mixtures thereof, and poly{[benzo(1,2-d:4,5-d')bisoxazole-2,6-diyl] 1,4-phenylene}, its cis isomer or mixtures thereof, and a solvent such as polyphosphoric acid;(ii) extruding the dope to form a film;(iii) imparting biaxial orientation to the film to increase the transverse strength thereof;(iv) solidifying the biaxially oriented film; and(v) washing the solidified film to remove the solvent. Also disclosed is a liquid crystal film produced by the above process.