Abstract: The present invention is directed to a process for forming a yarn having at least one conductive filament wherein the conductive and nonconductive filaments which make up the yarn are simultaneously co-spun. The present process can be performed at spinning speeds of above about 3500 meters per minute to produce a yarn useful in antistatic carpet production.
Type:
Grant
Filed:
October 5, 1992
Date of Patent:
January 11, 1994
Inventors:
Lawrence E. Blackmon, John D. Forster, Walter J. Nunning
Abstract: A method of making a porous polymeric material by heating a mixture of a thermoplastic polymer and a cationic or non-ionic surfactant having a hydrophilic-lipophilic balance range of 4.0 to 6.0 to a temperature and for a time sufficient for the polymer and surfactant to mutually dissolve. The mixture is then cooled to a temperature so that non-equilibrium liquid-liquid phase separation takes place to form a bi-continuous matrix of the polymer and surfactant so that the polymer and surfactant form two intermingled separate phases of large interfacial surface area. The surfactant is then removed from the polymer. The porous polymeric material produced by the above method has a lacey or filamentous structure consisting of a plurality of polymer strands connected together at spaced apart locations along each strand.
Type:
Grant
Filed:
September 4, 1992
Date of Patent:
January 11, 1994
Inventors:
Douglas L. Ford, Clinton V. Kopp, Robert J. W. Streeton
Abstract: The present invention relates to a carbon fiber bundle includes a regular coil-shaped fiber bundle and having excellent stretch characteristic. A process for producing a coil-shaped carbon fiber bundle according to the present invention includes the steps of compositing at least two kind of pitches to spin them as single fibers, bundling the thus spun single fibers to form a fiber bundle, then infusibilizing the resulting fiber bundler under tension and carbonizing the fiber bundle.
Type:
Grant
Filed:
September 28, 1992
Date of Patent:
January 11, 1994
Assignees:
Kao Oil Co., Ltd., Tanaka Kikinzoku Kogyo Kabushiki
Abstract: A method for making a semi-permeable microporous polymer sheet, useful as a separation membrane or the like, including extruding a melt-blended mixture of a high-temperature thermoplastic polymer and a leachable glass to form sheet and then leaching the glass from the sheet to leave a microporous relict polymer network, wherein the permeability of the sheet is improved by plasma-etching the surface of the sheet before or after leaching. Hydrophilic or hydrophobic porous membranes may be provided.
Abstract: An injection mold apparatus has a core and cavity halves. One or more gas poppet valves are affixed in the injection mold either in the movable and/or in the stationary halves of the mold. The poppet valves (or poppets) are located to open into a mold portion formed in the cavity between the movable portion of the injection mold and the fixed mold portion when the mold portions are closed. At least one gas line is connected to the poppets and to a gas pressure source and is adapted to open the poppets to the passage of nitrogen or other gas into the mold following the injection of molten plastic into the closed mold halves. Porous metal covers may be used to cover the opening in the mold either the movable and/or stationary halves of the injection mold in lieu of the gas poppet valves, and the gas pressure through the porous metal cover can be used to carry out the molding operation.
Abstract: Ion exchange membranes or films are made from a solution of perfluorinated cycloalkanes, perfluorinated aromatic compounds and perfluorotrialkyl amines having a critical temperature greater than 150.degree. C. and certain carboxylic fluorinated polymers having an equivalent weight greater than 900. A process for repairing ion exchange membranes and films by spray coating the surface of the membrane or film with the solution is also disclosed. The ion exchange membranes and films are useful in chloralkali cells or fuel cells.
Type:
Grant
Filed:
August 28, 1992
Date of Patent:
December 28, 1993
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Stephen A. Perusich, William H. Tuminello, Shoibal Banerjee
Abstract: An improved stereolithography system for generating a three-dimensional object by creating a cross-sectional pattern of the object to formed at a selected surface of a fluid medium capable of altering its physical state in response to appropriate synergistic stimulation by impinging radiation, particle bombardment or chemical reaction, information defining the object being structurally specified to reduce curl, stress and distortion in the ultimately formed object, the successive adjacent laminae, representing corresponding successive adjacent cross-sections of the object, being automatically formed and integrated together to provide a step-wise laminar buildup of the desired object, whereby a three-dimensional object is formed and drawn from a substantially planar surface of the fluid medium during the forming process.
Type:
Grant
Filed:
April 14, 1992
Date of Patent:
December 28, 1993
Assignee:
3D Systems, Inc.
Inventors:
Charles W. Hull, Stuart T. Spence, Charles W. Lewis, Wayne Vinson, Raymond S. Freed, Dennis R. Smalley
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.
Type:
Grant
Filed:
August 13, 1992
Date of Patent:
December 28, 1993
Assignee:
The Dow Chemical Company
Inventors:
Willard E. Alexander, Chieh-Chun Chau, Timothy L. Faley
Abstract: A film molding apparatus and molding method wherein a gel state film is immersed in a vessel of a film supply unit. The film contains at least 50 weight % swelling agent relative to a polymer constituting the film. The vessel is filled with soaking liquid which acts so as not to destroy a swelling condition of the film caused by the swelling agent. Specifically, the molding method includes the steps of providing the above-noted film, heating a mold press die used for molding the film, press-molding the film in the press die and substantially drying the film by evaporating the swelling agent.
Abstract: A graphite fiber having an elastic modulus E of 340-680 GPa, a microvoid radius of not larger than 20 .ANG. and a crystal size L.sub.c (.ANG.) satisfying the following formula:L.sub.c.sup.3 .ltoreq.0.918.times.10.sup.3 E-3.times.10.sup.5is valuable for a composite material having an improved compression strength. The graphite fiber is made preferably by oxidizing an acrylonitrile polymer precursor containing 0.05-8 wt. % of comonomer units and having an iodine adsorption amount of not larger than 3 wt. % and an orientation degree of at least 85%, at 200.degree.-300.degree. C. in an oxidative atmosphere under tension to obtain an oxidized fiber having a water adsorption of not larger than 7 wt. % and an orientation degree of at least 78%, followed by carbonization and graphitization of the oxidized fiber under tension.
Abstract: A method for producing ultra fine denier cellulose acetate fibers that entails spinning a spinning solution containing adequately high amounts of cellulose acetate in acetone wherein the cellulose acetate has a falling ball viscosity of 15 to 70 seconds wherein the spinning is conducted through spinnerettes having holes that have a diameter of less than 36 microns followed by drying at a temperature of about 50.degree. to 80.degree. C. at a draw ratio of 0.9 to 1.7.
Abstract: The process disclosed relates to the preservation of shellfish products so as to extend the shell-life of shellfish thereof. A thermally conductive mixture which forms a liquid barrier upon heating and a gel upon cooling is introduced to the shellfish container for packaging. Specific steps of heating to kill bacteria and other undesirable microorganisms and subsequent rapid cooling are required. Ultimate refrigeration of the packaged product is undertaken for long-term storage.
Abstract: Ultra-oriented, crystalline synthetic filaments with high tenacity are produced by extrusion of a fiber-forming synthetic polymer melt into a liquid isothermal bath maintained at a temperature of at least 30.degree. C. above the glass transition temperature of the polymer, withdrawing the filaments from the bath and then winding up the filaments. Polyethylene terephthalate filaments so produced at 3000-5000 m/min exhibit a crystalline structure and possess birefringence of 0.20-0.22, tenacity of 7-9 g/d, break elongation of 14-30% and boil-off shrinkage of 5-10%.
Type:
Grant
Filed:
February 4, 1992
Date of Patent:
December 7, 1993
Assignee:
North Carolina State University
Inventors:
John A. Cuculo, Paul A. Tucker, Gao-Yuan Chen, Ferdinand Lundberg
Abstract: A process for high stress spinning of polyethylene terephthalate yarns to produce a yarn of improved mechanical properties is disclosed. The process of the invention is conducted by spinning polyethylene terephthalate polymer through a spinneret having a plurality of rows of orifices wherein at least one row of orifices is larger than adjacent row of orifices. The yarn is quenched by contacting filaments issuing from the larger orifice with a quench medium prior to contacting of the yarn issuing from the orifices of smaller size. Thereafter, the yarn is drawn at a draw ratio which is at least about 85% of the maximum draw ratio of the yarn. A yarn having improved strength and/or a reduced fray levels is produced.
Abstract: This invention provides spiral-wound hollow fiber membrane fabric-containing cartridges and modules for separations and other phase contact applications, in which the cartridges contain baffles that induce radial feed fluid flow in the shell side of the hollow fiber membrane bundle; and methods for fabricating such cartridges.
Type:
Grant
Filed:
December 31, 1991
Date of Patent:
November 23, 1993
Assignee:
Hoechst Celanese Corporation
Inventors:
Ravi Prasad, Charles J. Runkle, Harry F. Shuey
Abstract: A method of molding an optical element in which a required amount of a resin material can be accurately supplied without air bubbles becoming entrapped in the resin material when it is supplied. The method includes a first step of making a tip of resin material supply means approach a molding surface until the tip is a predetermined distance away from the molding surface, a second step of discharging a predetermined amount of the resin material from the tip of the supply means while the tip of the supply means is the predetermined distance away from the molding surface, and a third step of discharging the resin material from the tip at a predetermined discharge rate, until a required amount of the resin has been supplied, while the tip of the supply means is moved in a direction away from the molding surface as the lower end of the resin material discharged from the tip is maintained in contact with the molding surface.
Abstract: A three-dimensional printed circuit assembly is formed by first making a substrate (20). A substrate (20) is first formed from a photoactive polymer (14) that is capable of altering its physical state when exposed to a radiant beam (30). At this point, the substrate is only partially cured. A conductive circuit pattern (50) is then formed on the partially cured substrate. The substrate is then molded to create a three-dimensional structure, and then further cured to cause the photoactive polymer to harden.
Type:
Grant
Filed:
October 22, 1992
Date of Patent:
November 23, 1993
Assignee:
Motorola, Inc.
Inventors:
Frank J. Juskey, Anthony B. Suppelsa, Dale W. Dorinski
Abstract: This invention is for a process for making a formed, and compressed food material into a toroidal shape, between two continuous sheets of food grade plastic film, which are sealed to each other around the inner and outer perimeters of the toroidal shape. The process employs two polygonal forming cylinders which are translatable towards each other to perform the the forming, compressing, and sealing steps by translational motion of at least one of the cylinders, and thereafter to advance the food package formed thereby by the rotation of the polygonal cylinders. The process is characterized by its capability to preserve the purity of the food materials passing through the process.
Abstract: A hydrophilic polytetramethylene adipamide microporous membrane has a narrow pore-size distribution. The membrane is formed by a rapid quench process in a quench bath having solubility parameter above about 21 Hildebrands.
Abstract: Molding a hollow shaped body which has a skin made of a synthetic resin and a hollow portion therein by a mold block provided with a mold cavity in the shape of the hollow shaped body, a tub into which an excess amount of the synthetic resin can flow and a small flow path communicating between the mold cavity and the tub. The process includes forming the skin of the hollow shaped body by injecting a molten synthetic resin into the mold cavity to fill up the cavity. Thereafter, a gas is introduced into the injected synthetic resin to thereby form the hollow portion. The gas injection forces a part of the synthetic resin out of the mold cavity and into the tub through the small flow path.