Abstract: A process for spinning a fully water washed fluorinated olefinic polymer intermediate fiber structure from a mixture of an aqueous dispersion of particles of the fluorinated olefinic polymer and a solution of a cellulosic ether.

Abstract: A process for the preparation of polybenzazole filaments which comprises (a) extruding a solution of polybenzazole polymer in a mineral acid through a spinneret having at least 100 holes, which are arranged to form a annular pattern around the center of the spinneret, the center and at least two radial sections of the spinneret having no holes and an average width which is at least about 3 times the minimum pitch of the holes, thereby forming filaments of the polymer solution; (b) drawing the filaments of the polymer solution through a quench chamber while providing a substantially radial gas flow therein across the spinneret from at least two different directions; and (c) washing and drying the filaments of the polymer solution under conditions sufficient to form polybenzazole filaments.

Abstract: A continuous process for preparing nonwoven fabrics of polybenzazole filaments, which comprises spinning at least two polybenzazole dope filaments simultaneously, and intermingling and depositing the filaments on a substantially planar collecting surface, thereby forming a nonwoven fabric.

Abstract: A synthetic reinforcement having surface features that facilitate adhesion of the reinforcement to another surface and a process for making the same is disclosed. The synthetic reinforcement is comprised of a plurality of continuous fibers that are maintained in position by a resin encasement. An external surface of the synthetic reinforcement can be characterized by micro-recesses that are located in a generally random pattern, which increases the surface area of the resin encasement.

Abstract: A process of manufacturing lyocell fiber with an increased tendency to fibrillation which includes dissolving cellulose in a tertiary amine N-oxide solvent to form a solution. The degree of polymerization of the cellulose is not more than about 450 and the concentration of cellulose in the solution is at least 16 percent by weight. The solution is extruded through a die to form a plurality of filaments which are washed to remove the solvent, thereby forming the lyocell fiber which is then dried.

Abstract: A collagen-hydrogel for promoting epithelial cell growth and regeneration of the stroma is shown. Also shown is an optical lens for the eye, fabricated from the collagen-hydrogel, which, when affixed to Bowman's membrane, promotes and supports epithelial cell growth, enables corneal epithelium of the cornea of an eye, during the healing process, to attach to and cover the anterior surface of the lens implanting the same and to regenerate the stroma which grows over the edge of and attaches to the optical lens. Laid down in the layers of the regenerated stroma are new keratocytes and collagen fibial produced from keratocytes. The collagen-hydrogel is a hydrogel polymer formed by the free radical polymerization of a hydrophilic monomer solution gelled and crosslinked in the presence of an aqueous stock solution of collagen to form a three dimensional polymeric meshwork for anchoring collagen. The collagen-hydrogel material has a ratio by weight of collagen-to-hydrogel in the range of about 0.

Abstract: A process for the production of polyimide fibers includes having the fiber spun from a fully aromatic polyamide acid solution in an aprotic amide solvent in an aqueous-organic bath and subjected to plasticization drafting. It is washed until a 2-4 wt. % content of the organic solvent per fiber is attained and treated with organic or inorganic acids until a 0.5-1.0 wt. % content thereof per fiber is attained. Thereafter, fibers are dried and heat-treated.

Abstract: The invention relates to polyketone yarns of which the maximum tangential modulus at an elongation of more than 0.2% is at least 10 N/tex which display both high strength and, if so desired, a high elongation at break. The quality number, which is measured on a single filament out of a bundle of at least about 30 filaments spun simultaneously through one spinneret and given as .sigma., .epsilon., is higher than 85 mN/tex, preferably higher than 100 mN/tex. The quality number of a yarn spun through one spinneret of one or more holes is higher than 110 mN/tex, preferably higher than 120 mN/tex. The yarns are manufactured by extruding a solution of a linear polymer of alternating ethylene and carbon monoxide units in a resorcinol-containing solvent, after which the solvent is removed with the aid of methanol as coagulant.

Abstract: The present invention provides a process for preparing a high water-containing elastomer medical catheter and a urinary catheter prepared by the process. The process is carried out by a) heating a mixture consisting of polyvinyl alcohol, water, sulfoxide and linear alkane, in a sealed vessel with agitating; b) pouring the resulting homogeneous fluid into a mould; c) solidifying the fluid by cooling; d) releasing the solidified fluid from the mould; and e) heat-treating the resulting medical catheter and washing with a polar organic solvent. The medical catheter and the urinary catheter of the present invention have excellent lubricity.

Abstract: A process for wet spinning a meta-aramid polymer solutions having a salt content of at least 3 percent by weight produces a one step, fully wet drawable fiber that has desirable physical properties without subjecting the fiber to hot stretching.

Abstract: Process for the production of cellulose fibres having a reduced tendency to fibrillation, in which a solution of cellulose in a tertiary amine-oxide is spun into fibres and the freshly spun fibres are contacted with a textile agent comprising at least two reactive groups, and are heat-treated, characterized in that the heat treatment is carried out by means of irradiation with electromagnetic waves.

Abstract: The invention is concerned with a process for the production of cellulose moulded bodies, particularly films and fibres, by extruding a solution of cellulose in a tertiary amine-oxide through a shaping device, for example a spinneret, and conducting the extruded moulded body while drawing it into an aqueous precipitation bath, in which it coagulates, whereafter the coagulated moulded body is washed with an aqueous washing liquid, characterized in that the precipitation bath employed for coagulation and/or the washing liquid employed for washing contain(s) a surfactant in dissolved form.

Abstract: An increased efficiency method and apparatus 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 interior 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 protect the underlying mortar from scouring, while tolerating a low-velocity flow of water, 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 method and apparatus for establishing the magnetic permeability of a batch ferrites at a predetermined target permeability. Ferrite parts are sintered to achieve a magnetic permeability greater than the target permeability. The sintered parts are then tumbled to suppress the magnetic permeability below the target permeability. The parts are then exposed to a chemical wash to increase the magnetic permeability and continuously monitored to allow setting the magnetic permeability at the target permeability.

Abstract: Methods are disclosed for making semipermeable membranes from cellulose acetate and for making medical devices therefrom. In the process, a molten liquid comprising cellulose acetate (CA), a solvent for CA, and a non-solvent for CA is extruded to produce a membrane. The solvent and non-solvent are removed from the membrane to produce a semipermeable membrane having a water permeability. The semipermeable membrane is impregnated with a liquid consisting essentially of water to render the semipermeable membrane capable of being stored until time of use without undergoing a substantial loss in water permeability. The semipermeable membrane can be incorporated in a casing in order to produce a medical product, wherein the membrane is impregnated in the product.

Abstract: Soluble wholly aromatic polyamide is obtained by low-temperature polycondensation in an amide solvent such as N-methyl-2-pyrrolidone. The reaction mixture is neutralized with an alkali and spun into fibers by wet spinning, coagulated in a salt-free aqueous solution of an organic solvent, preferably the polymerization solvent, and subsequently drawn in another aqueous solution of the same organic solvent, both solutions being substantially at ambient temperatures below 50.degree. C. but above freezing, More than 60% of the total fiber drawing is executed in this low-temperature draw stage.

Abstract: A method for producing a wall, roadway, sidewalk or floor of cementitious material having the appearance of natural stone and mortar including a base with an outer surface with a plurality of irregular shaped protrusions disposed in a random pattern to simulate natural stones and a plurality of simulated grout lines formed therebetween, the method including the steps of preparing a cementitious material, pouring the cementitious material into a form, vibrating the cementitious material, allowing the cementitious material to cure forming the base with the outer surface, releasing the base with the plurality of irregular shaped protrusions disposed in the random pattern to simulate natural stones and the plurality of simulated grout lines formed therebetween from the form, coloring the outer surface and accenting the plurality of simulated grout lines.

Abstract: This invention relates to flexible cellulose fibers with a reduced modulus and a decreased NMR degree of order, particularly for use in the textile field, which are obtained by pressing out solutions of the cellulose in hydrous NMMNO through spinning nozzles along an air travel into an NMMNO-containing aqueous and/or alcoholic precipitation bath as well as by a conventional rinsing, aftertreatment and drying, with strengths of between 15 and 50 cN/tex, and to a process for their production. According to the invention, these flexible cellulose fibers have an initial modulus of less than 1,500 cN/tex, and the relationship of the heights of the lines at 88 ppm and 85 ppm above the spectrum base line in the highly resolved .sup.13 C-NMR solid-body spectrum is .ltoreq.1.

Abstract: A multi-layer flexible article includes a first layer of natural rubber, a second layer of natural rubber, polyurethane, poly(acrylamide-acrylic acid, sodium salt) and polyethylene oxide and a third layer of acrylic copolymer and fluorocarbon telomer resin. The article is preferably a glove formed by the method of dipping a hand shaped mold into baths containing aqueous emulsions of the components used to form the layers. Gloves manufactured according to the method are substantially wet-hand and dry-hand donnable as compared to powdered latex gloves of similar size. The finished gloved is water washed and wet autoclaved to substantially reduce the protein content from the natural rubber and substantially remove other water extractable allergenic moieties. The washing and autoclaving renders the glove substantially hypoallergenic as compared to gloves not so treated.

Abstract: The invention is a process for the preparation of polybenzazole staple fibers which includes extruding a solution of polybenzazole polymer to form a dope filament, cutting the dope filament to a desired length, and washing and drying the cut filament. It has been discovered that the process of the invention provides a suitable means to prepare staple fibers which does not require the cutting of washed, rigid polybenzazole filaments.

Abstract: A process for producing a fiber or film of regenerated cellulose from a composition having a base of cellulose formate is provided. The composition is characterized by the following: (1) the composition is a solution; (2) the concentration of cellulose formate in the composition is at least 8% by weight; (3) the degree of substitution of the cellulose by formate groups is greater than 20% and (4) the composition contains one or more compounds selected from among alkylsulfoxides, lactams, acrylic amides and cyclic derivatives of urea as a solvent. The process for producing the fiber or film involves (i) transforming the composition into a liquid extrudate having the form of a fiber or film at a temperature at which the solution is isotropic at rest; (ii) coagulating the liquid extrudate; (iii) regenerating the cellulose of the fiber or film obtained and (iv) washing and drying the regenerated cellulose fiber or film.

Abstract: Multi-step methods of making a non-skinned isotropic microfiltration membrane, the common steps of which include heating a PVDF-type casting dope above its cloudpoint, forming a film, and immersing the film in a gelation bath.

Abstract: This invention relates in general to a method for the formation of films having a controlled molecular orientation prepared from rod-like extended chain aromatic-heterocyclic ordered polymers, and containing a binder in the micro-infrastructure. Such films have high tensile strength, modulus, and environmental resistance characteristics.

Abstract: A synthetic reinforcement having a plurality of recesses on a surface to facilitate adhesion to wood structural members and a process for making the same is disclosed. The synthetic reinforcement is comprised of a plurality of continuous fibers that are maintained in position by a resin encasement. The surface of the synthetic reinforcement is characterized by recesses that are located in a generally random pattern, which increases the surface area of the resin encasement. The synthetic reinforcement is connectable to wood laminae or itself with commercial grade adhesives such as the resorcinol resins, which are suitable for adhering the wood laminae together.

Abstract: A process for detecting fine particles includes the steps of forming a sublimable thin film on an essential surface of a wafer on which fine particles are present, irradiating laser beam at the surface of the wafer, receiving a reflected beam from the surface which is scattered by the presence of the fine particles, and detecting the particles from the received scattered beam. The process may further include the step of accomplishing an etchback against the sublimable film to partially retain the sublimable film adjacent the surface of the fine particles. The film can be prepared from one or a mixture of gases including free sulfur generatable gas under discharge-dissociation conditions. Sulfur compounds or polythiazyl are preferable. Alternatively, the film can be made of a condensed film of organic solvent vapor. The sublimable film is sublimed by heating after the step of detecting the fine particles.

Abstract: A method for preparing optical quality, thin films of rigid-rod polymers and co-polymers, as well as blends of such polymers or co-polymers with flexible coil-like aromatic heterocyclic polymers and co-polymers which comprises(a) preparing a solution of the rigid-rod polymer or co-polymer or blend in a suitable solvent;(b) forming a film from the solution;(c) exposing the film to a non-solvent vapor for about 1 to 5 minutes per micron thickness in the finished film; and(d) coagulating the film in a non-solvent.This method can be employed to prepare films of high nonlinear optical susceptibility for electro-optical device applications. Because of their thermal stability, mechanical strength and chemical resistance, films prepared according to this method can also be used as filters and separation membranes.

Abstract: A woven synthetic fabric tubular vascular graft including, a stiffening component in the filling yarn is self supporting without crimping the walls of the graft. The graft is woven from warp ends of multifilament polyester yarns and elastomeric yarns in the warp and a filling yarn which includes multifilament and monofilament polyester yarns which have been twisted together. Longitudinal and radial compliance provide for improved kink resistance making the tubular grafts suitable for use in medium and small diameter peripheral applications. A preferred graft has an outer velour surface and a smooth inner surface.

Abstract: A method which includes enhancing effects upon treating the surface of a thermoplastic resin article by a surface-activating treatment such as corona discharge and the like or by a primer treatment and, thereby, improving coating performance, printability, adhesiveness and so forth of the thermoplastic resin article. The resin article is subjected to a surface-heating treatment which comprises heating only surface layer of the resin article up to a melting point of the thermoplastic resin or a higher temperature followed by cooling the surface layer, and then, subjected to the surface-activating treatment or primer coating.

Abstract: A method of evacuating uncured resin from internal passages of semi-hollow stereolithographically produced objects includes, subjecting the object to air flow for between about 0.5 hours and about 2 hours, at a temperature greater than about 75.degree. F.; externally cleaning the object with alcohol; submerging the object in a bath of alcohol, wherein the bath is internally agitated; removing the object from the bath and repeating the above steps to displace any residual resin, wherein total object exposure time to alcohol does not exceed three hours.

Abstract: A spin finish is applied to one or more as spun filaments. The spin finish, which can be a solution of glycerin in a solvent, can be easily removed from the filaments if desired by a water wash. Preferably, the spin finish is non-toxic and the filaments treated therewith are useful in forming surgical devices.

Abstract: A porous polyurethane tube suitable for use as a vascular graft prosthesis is prepared by placing solvent type polyurethane resin coated mandrel in a static coagulant consisting of water, ethanol and optionally aprotic solvent within 30 seconds immediately after the coating step, separating the tube by placing the mandrel in a swelling agent containing at least 90 percent by weight of ethanol and rinsing with a solution containing at least 80 percent by weight ethanol.

Abstract: Viscose filaments, preferably in staple fibre form, which have a decitex of less than 5.0 and a multi-limbed cross-section, the limbs having a length-to-width aspect ratio of at least 2:1. Examples of multi-limbed cross-sectional shapes are Y-, X-, H- and T-shapes. The fibre can be formed into woven, non-woven or knitted fabrics, and is especially useful for absorbent products.

Abstract: High molecular weight polyester fibers having excellent mechanical strength and useful for various industrial materials, is produced by dry-jet wet spinning a dope solution of a polyester resin comprising repeating ethylene terephthalate units, having an intrinsic viscosity of 1.2 or more and dissolved in a phenolic solvent, through a spinneret, coagulating the resultant filamentary dope solution streams in a bath of coagulating liquid in which the phenolic solvent is soluble and the polyester resin is insoluble, while controlling the temperature of the coagulating liquid to a level of from (Tg-50.degree. C.) to (Tg+45.degree. C.) wherein Tg represents a glass transition temperature of the dope solution, and optionally subjecting the resultant undrawn polyester filaments to a rinsing step with a rinsing liquid, to a drawing step at a total draw ratio of at least 5, and to a heat-treating step.

Abstract: This invention relates to the preparation of, and a device for using, a permanently deformed sulfonated halopolymer article. A flexible and non-brittle flange may be formed from at least one end of a hollow perfluorosulfonic acid membrane in one aspect of the invention. The flanged membrane is particularly useful for quick attachment and detachment to various instrumentation used for pervaporation. In addition, by packing the membrane with a means for increasing radial diffusion of fluid within the membrane, pervaporation efficiency may be increased.

Abstract: Improved polybenzoxazole fibers are made by a process for finishing a spun and drawn dope fiber, which contains polybenzoxazole polymer and polyphosphoric 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 phosphorus (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 3 weight percent residual moisture; and(d) heat-treating the fiber at a temperature of at least about 300.degree. C. under tension.

Abstract: A method for preparing hydrophobic fiber for processing, inclusive of crimping, cutting, carding, compiling and bonding, without substantial loss in hydrophobic properties in the finished staple or corresponding nonwoven product through initial application of a surface modifier component comprising one or more of a class of water soluble compounds substantially free of lipophilic end groups and of low or limited surfactant properties.

Abstract: An elongate member of cellulosic material, such as fiber, having a reduced tendency to fibrillation is produced by a solvent-spinning process which includes the steps of: (i) dissolving cellulose in a solvent miscible with water to produce a dope; (ii) forcing the dope through at least one orifice to produce an elongate form; (iii) passing the elongate form through at least one water-containing bath to remove the solvent and produce the elongate member, and (iv) drying the elongate member to produce a dry elongate member, and is characterized in that the pH of each of the baths through which the elongate form and the elongate member pass during processing between production of the elongate form and the drying of the elongate member is maintained at a figure of 8.5 or less.

Abstract: A washing method for a workpiece, a resin molded product and a manufacturing method for a resin molded product. There are three steps involved, a detergent washing step, a rinsing step and a drying step. In the detergent washing step there is an additional step in which the detergent water is separated into a condensed liquid and water vapor, the water vapor being discharged into the air. The apparatus used in the method consists of degreasing baths, and withdrawal baths for the detergent wash, a pure water bath for rinsing and a drying bath. The apparatus also has an air heating unit which supplies hot air to form the water vapor in the separation step of the detergent water.

Abstract: There are disclosed flame-retardant, high temperature resistant polyimide fibers of the general formula ##STR1## wherein n is an integer larger than 1, A is a tetravalent aromatic group and R is at least one divalent aromatic group. These polyimide fibers have been heat-treated in the unstretched state and have a maximum shrinkage of 14% when heated to a temperature of 400.degree. C. These polyimide fibers are produced by initially spinning crude fibers from a solution of the appropriate polyimide in an aprotic organic solvent, preferably according to the dry-spinning method, which solution optionally contains additives. The crude fibers obtained are washed with water to remove the solvent. The washed crude fibers are dried to a moisture content of less than 5% by mass, are subjected to a heat treatment at a temperature of between 315.degree. C and 450.degree. C, are cooled and, if desired, are crimped and cut to staple fibers.

Abstract: A method of producing replicated paving stone including a base having a shaded and stratified layered upper surface with a plurality of simulated grout lines formed therein including the steps of preparing a cementitious mortar, applying a release agent to the interior of a forming mold, pouring the cementitious mortar into the forming mold, leveling the mortar, vibrating the forming mold and cementitious mortar therein, allowing the cementitious mortar to cure forming a base with an upper surface, releasing the base from the forming mold, applying an acid stain to the base, allowing the acid stain to etch the base to shade the upper surface, accenting the plurality of simulated grout lines with a pigment and sealing the replicated paving stone with an acrylic polymer sealer.

Abstract: A method of applying porous building plates includes applying plate-like porous building plates having pores on the surfaces and then jointing them by means of a coated joint method. In the method, the pores on the surfaces of the porous building plates are packed with an acid soluble substance and then the plates are joined by means of a coated joint method. Subsequently, the surfaces of the porous building plates are washed with an acid.

Abstract: Polymeric feedstocks, such as scrap or waste tires, rubber, and plastics, in a size range of -6 to +25 mesh are washed with an organic solvent to remove stabilizing additives which have migrated to the surface of the polymer particles, thus eliminating the stabilizers from participation in subsequent reactions and allowing the final production of more pure monomeric products. The polymer particles are exposed to ozone under conditions to cause stress cracking, fissuring and cleavage of the polymer feedstock particles. The ozonated polymer particles are depolymerized to produce one or more monomeric compounds, with the reaction taking place rapidly and occurring in the presence of a system of one or more catalysts which may be metallic salts. The depolymerization is accomplished under conditions of elevated temperatures and reduced pressure, the conditions being less severe than those conditions associated with thermal pyrolysis.

Abstract: Used foils made of polyethylene are shredded and, in a solvent bath containing an organic solvent, subjected under intensive motion, for example through mechanical stirring, to a frictional surface cleaning, and simultaneously to an extraction without dissolving the plastic material. By the extraction, ingredients added to the foils and PE waxes are separated from the shreds, and the printing inks are removed especially through the frictional surface cleaning.

Abstract: An electrically conductive composition of (a) at least one oxidized polycationic polyheteroaromatic compound and (b) at least one polyanion of a film-forming thermoplastic polymer containing sulfated alcohol groups ##STR1## in repeating structural units in form of films or filaments is drawn at temperatures below the melt/decomposition temperature to increase electrical conductivity and to improve mechanical properties. The material may be used as electrodes, electrically conductive filaments or components for electromagnetic screening.

Abstract: A multi-layered conjugated acrylic fiber comprises different acrylic polymers which are conjugated along the fiber axis in layers. On the average the fiber contains more than two layers of acrylic polymers. The shrinkage forming ratio in boiling water of the conjugated acrylic fiber is 7-15% and the shrinkage forming stress is 5-20 mg/denier. To make the acrylic fiber water absorbent, one or more of the acrylic polymers may contain 0.3 to 2.0 mmole/g of carboxylic acid groups. The fibers may be made by introducing the polymers into a static mixer in such a way as to retain a number of separate layers of the polymers, and thence to a spinneret through a filter having a maximum mesh space of 10 or more. After spinning out the dope, it is drawn, washed and dried. Except where water-absorbent fiber is wanted, this is followed by shrinkage forming treatment and redrawing; the water-absorbent fiber is treated with alkali solution either in the form of yarn, or a fabric made therfrom.

Abstract: A process for coagulating a polybenzazole film which includes contacting a lyotropic polybenzazole dope film that is constrained in at least two directions with a coagulant under conditions such that the polybenzazole polymer separates as a gelled moiety with the structure set such that further removal of solvent will result in no more than a 5% increase in the force necessary to constrain the film.

Abstract: Polybenzazole polymer dopes are spun into fibers at high speed by passing through a spinneret with proper selection of hole geometry, followed by spin-drawing to a spin-draw ratio of at least 20, washing, taking up and drying. The take up speed is at least about 150 meters per minute, and the fibers are spun in at least 10 km lengths without a break.

Abstract: A suture strand is subjected to dynamic treatment by passing the suture with multiple turns around at least two godets located within a heating zone provided by an oven. The suture strand can be bioabsorbable or non-bioabsorbable, and either monofilament or multifilament. A combination of large and small diameter godets in the oven can achieve dynamic relaxation or stretching.

Abstract: Films made from polybenzazole dopes can quickly be leached to remove polyphosphoric acid and other residual solvents by passing a leaching fluid such as steam through pores in the wet, never dried film. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.

Abstract: Articles (other than fiber) made from polybenzazole dopes can quickly be washed to remove polyphosphoric acid by a combination of initially washing with an acidic liquid and second washing with a hot leaching fluid at at least about 60.degree. C. The process can reach acceptable residual phosphorous levels (1500-2000 ppm) in as little as about 2 or 3 minutes.