Abstract: A hollow blow-molded bottle-shaped container of a biaxially oriented polyethylene terephthalate which advantageously has a crystallized outer peripheral portion at the neck portion except the boundary between the neck portion and the body portion and non-crystallized inner peripheral portion thereat. This bottle-shaped container is molded by a method of molding the same, which method advantageously has the steps of injection-molding a piece or parison formed at the outer peripheral surface of a neck root part forming portion in a downwardly flared tapered shape, and crystallizing by a heat treatment the outer peripheral surface portion of the neck root part forming portion. Thus, the deterioration in the physical properties of the neck and shoulder portions of the bottle-shaped container thus finally blow-molded can be reduced.

Abstract: Spherulites are grown in such sections as neck, neck end, bottom center and/or bottom periphery of a hollow bottle-shaped container of biaxially oriented-blow molded polyethylene terephthalate (PET) resin where the resin is not substantially subjected to orientation, thereby to improve the thermal resistance, stiffness and content resistance of such sections to almost the same extent as the biaxially oriented sections of the container such as the shoulder and cylindrical sections thereof. The aforesaid non-oriented sections of the preformed piece before being blow-molded or of the blow-molded container are first heated at or above the glass transition temperature of the resin for about 2-8 minutes and are then annealed at room temperature, with the result that such sections have a spherulite texture of an increased density and are rendered opaque.

Abstract: A polyester film for printed circuits to be used as a base in a printed circuit base plate or as a base and/or cover layer in a printed circuit board, which undergoes a degree of dimensional stability of not more than 1% in both the longitudinal and transverse directions when kept at 150.degree. C. for 30 minutes, and which is obtained by heat treating an extrusion molded and stretched polyester film at 150.degree. C. to 240.degree. C. without applying tension.

Abstract: A method of producing a container of polyethylene terephthalate or similar thermoplastic material from a tubular blank of amorphous material. A mechanical forming element moves a transitional zone between amorphous (thicker) material and thinner oriented material stretched to flow during simultaneous elongation of the blank in the direction of movement of the transitional zone. The stretched and oriented material is heated to a temperature higher than the temperature of the material immediately before stretching. As a result, the internal stresses produced in the material during earlier stretching are relieved. Heating causes the length of the material in the direction of stretching also to be reduced. Each subsequent forming stage for shaping the container takes place at a temperature lower than the temperature at the immediately preceding forming stage.

Abstract: Crystalline polymers having a relatively high melt index and low structured carbon black together produce positive temperature coefficient material which can attain suitable volume resistivity with a greatly reduced annealing time. Temperature self-regulating resistive heating elements may be made with the material in a continuous process where annealing is conducted in a heated zone while the extruded element is in motion or during a short interval when its motion is interrupted.

Abstract: The present invention relates to a credit card or identification card fabricated from amorphous polyester sheet material wherein at least the area of said card containing embossed numerical or letter characters and the characters themselves are composed of substantially crystalline polyester. Such characters can not readily be altered by either heat treatment or by shaving them off.

Abstract: A method is described for adjusting the temperature coefficient of the ferrimagnetic resonant frequency in gallium or aluminium substituted YIG disc resonators. At the compensation temperature, T.sub.o, the temperature coefficient of the resonant frequency, f.sub.r, in a given frequency range is approximately zero. Where this range lies, depends, inter alia, on the substitution value. By annealing the discs, T.sub.o can be moved into the desired temperature range. When the manufactured disc has a compensation temperature above the desired temperature range, annealing must be carried out at approximately 850.degree. to 1400.degree. C. When the manufactured disc has a compensation temperature below the desired temperature range, annealing is performed at approximately 400.degree. to 850.degree. C.

Abstract: In the manufacture, for use in an optical cable element, of a tube of polymeric material, the drawn down extruded polymeric tube is annealed by causing it to travel through at least one elongate oven into which is injected, at a position intermediate of the ends of the oven, air or other gas which will have no deleterious effect on, and which is at a temperature sufficient to effect annealing of, the drawn down polymeric tube, and by directing the injected hot air or other gas on to the advancing drawn-down tube at a plurality of positions spaced along the length of the oven in such a way that turbulent flow and substantially even distribution of hot gas is provided around the advancing drawn-down tube. Use of this method of annealing enables the speed of manufacture to be at least twice the speed of manufacture hitherto achieved.

Abstract: Porous hollow fibers composed of a high density polyethylene the fibers having rectangular micropores that are oriented in the lengthwise direction of the fibers and having a porosity from 30 to 90% by volume are disclosed. Membranes composed of hollow fibers exhibit a water permeability of greater than 65 (ml/m.sup.2, hr, mmHg) as well as a human serum albumin permeability of greater than 30%. Such fibers are suited for use as filters, particularly as a membrane for simple fractionation of whole blood into it plasma and cellular components. The hollow fibers are obtained by spinning a high-density polyethylene under a high-draft condition followed by cold stretching and hot stretching, and without the use of any solvent or plasticizer.

Abstract: Method for producing a polycrystalline body comprised of from about 50% by weight to about 95% by weight of mullite and from about 5% by weight to about 50% by weight of cordierite, said body having a porosity of less than about 10% by volume.

Abstract: There is described a process and apparatus for flaring the end of a thermoplastic tube to form a flange thereon to provide a flanged adapter for joining sections of plastic pipes. An end portion of a tube of suitable thermoplastic resin is heated to soften it and is then placed in a flanged sleeve with the heated tube end projecting from the sleeve. A flanged male plug is inserted into the heated end of the tube and the plug is pushed by means of a press into the tube to cause the flanged plug to flare the heated end of the tube outwardly through an obtuse angle against the flange of the sleeve so that a flange is formed on the tube. A cylindrical member embraces the flanges of plug and sleeve and limits outer flow of the formed tube flange. The tube is then cooled in situ in the press, is removed from the press after cooling and placed in a cold water tank for further cooling. After cooling, the flanged tube is constrained between top and bottom clamping disks and is reheated to about 160.degree. F.

Abstract: The present invention relates to a credit card or identification card fabricated from amorphous polyester sheet material wherein at least the area of said card containing embossed numerical or letter characters and the characters themselves are composed of substantially crystalline polyester. Such characters can not readily be altered by either heat treatment or by shaving them off.

Abstract: A process for improving the high temperature flexural strength of titanium diboride-boron nitride (TiB.sub.2 -BN) intermetallic compositions which comprises reheating hot pressed TiB.sub.2 -BN stock to about 2000.degree. C. for about four hours in an inert atmosphere.

Abstract: A membrane cast in the form of either a hollow filament or a flat film formed of a polybenzimidazole polymer is subjected to an annealing process by contacting the membrane with a non-aqueous annealing medium comprised of a solvent for the polymer and a non-solvent for the polymer. Such an annealing step can advantageously occur at an annealing temperature below about 125.degree. C. (e.g., below 100.degree. C.) These polybenzimidazole membranes find particular utility in reverse osmosis desalination processes. The annealing step of the present invention improves the mechanical and separative properties of the membrane.

Abstract: A fiber consisting essentially of polyethylene terephthalate capable of being dyed under normal pressure and having an initial modulus at 30.degree. C. of about 55 g/d to about 130 g/d, a relationship between a peak temperature [T.sub.max (.degree.C.)] at the peak of a dynamic mechanical loss tangent (tan .delta.) measured with a frequency of 110 Hz and a peak value of the dynamic mechanical loss tangent [(tan .delta.).sub.max ] represented by the formula:(tan .delta.).sub.max .gtoreq.1.times.10.sup.-2 (T.sub.max -105)and a (tan .delta.).sub.max of about 0.14 to about 0.30 and a dynamic mechanical loss tangent at 220.degree. C. (tan .delta..sub.220) of at most about 0.055. The fiber is produced by subjecting a polyethylene terephthalate fiber obtained at a spinning speed of at least about 4000 m/min. to heat treatment at a temperature ranging from a temperature at which a dynamic modulus (E') of the fiber deviates from a tangent line at 180.degree. C.

Abstract: In a method of fabrication of piezoelectric polymer transducers by forging, a preform is subjected to flattening by compression in order to produce a radial orientation of the molecular chains constituting the polymer with respect to the center of pressure.

Abstract: A greige fabric containing a polyester yarn having high and low shrinkage regions along the filaments, out of phase from filament to filament, is bulked by shrinking the unrestrained fabric, then heating the fabric sufficiently to make the fabric elongate in the direction of the polyester yarn.

Abstract: A method for stabilizing the Tmc of PPS subjected to heat treatment in a temperature range between 240.degree. C. and 320.degree. C., particularly during the heating process of an extrusion operation, by increasing the tmperature of the polymer through the 240.degree. C.-320.degree. C. range at a rate of at least 20.degree. C. per minute or by subsequently raising the temperature of the polymer to at least 350.degree. C. for a time sufficient to stabilize the Tmc of the polymer.

Abstract: Aromatic polyamide filaments are treated at high speed under tension by passage over an array of closely spaced, heated rolls at 175.degree.-300.degree. C., the filaments stretched 0-1.6% and passed over a second array of additional closely spaced, heated rolls at 175.degree.-300.degree. C., cooled and wound up.

Abstract: A process for producing high precision apertures in plastic components comprises the steps of: injection molding the component from a crystalline or semicrystalline thermoplastic material wherein at least one aperture is formed in the component during the molding step; inserting an annealing rod having an oversized diameter with respect to the aperture into the aperture; placing the component, with the annealing rod inserted into the aperture, into an oven at an elevated temperature for a period of time; allowing the component to cool; and withdrawing the annealing rod from the aperture of the component.

Abstract: A process is disclosed for the manufacture of nylon packaging film having improved slip characteristics. In the process a homogeneous mixture is formed from a film-forming nylon resin and between 0.05 and 1.0 percent by weight thereof of a material selected from the group consisting of (1) secondary amides of the formula ##STR1## and (2) N, N' ethylene bis amides of the formula ##STR2## where R.sub.1 and R.sub.2 are aliphatic hydrocarbon chains of C.sub.14 -C.sub.22. The homogeneous mixture is then extruded into film subsequently, the film is heated to a temperature between 40.degree. C. and 150.degree. C. for a period of 2 to 30 minutes in order to accelerate the development of improved film slip characteristics. The nylon film having improved slip characteristics is useful for the packaging of bacon and other processed meats.

Abstract: A method is disclosed for reducing post-molding shrinkage of a hollow oriented polyethylene terephthalate container; the method including the steps of:(1) bringing a polyethylene terephthalate parison to orientation temperature,(2) blow molding the parison to provide a biaxially oriented container with larger dimensions than desired in the final container,(3) heating the blow molded container for a time and temperature sufficient to shrink the container to the desired size whereby substantially all the time-temperature dependent shrinkage is accomplished.

Abstract: A method of strengthening the neck portion of a hollow blow-molded bottle-shaped container of a biaxially oriented polyethylene terephthalate resin, which has the steps of heating the neck portion from 140.degree. to 170.degree. C., inserting a die pin of a predetermined shape into the opening of the neck portion, blowing cooling air to the neck portion, thereby shrinking and whitening the neck portion. Thus, the method prevents improper shrinkage deformation of the neck portion due to the thermal influence of the bottle-shaped container.

Abstract: A non-linear voltage limiting device displaying a particular stability characteristic and designed to eliminate flashover failure across its circumferential edge is disclosed herein along with a specific method of fabrication. The voltage limiting device is characterized by a rising resistive current with time at predetermined temperature and voltage levels and includes a disc-shaped wafer composed primarily of zinc oxide. In accordance with the method disclosed herein, after this wafer is formed and sintered in accordance with prescribed temperature and time requirements, its circumferential edge is provided with an anti-flashover coating which requires curing. Thereafter, the coated wafer is annealed in a way which cures the coating and, at the same time, reduces and preferably minimizes the resistive current rise characteristic referred to above.

Abstract: The invention relates to an earplug, produced with the use of a polysiloxane which is made foamable and cross-linkable by the use of expanding and cross-linking agents. The method for producing such an earplug comprises preshaping the polysiloxane together with the additives, then finally shaping the earplug in the foaming process and then tempering the finally shaped product.

Abstract: A membrane cast in the form of either a hollow filament or a flat film formed of a polybenzimidazole polymer is subjected to an annealing process by contacting the membrane with an annealing medium comprised of a solvent for the polymer and water. Such an annealing step can advantageously occur at an annealing temperature below the boiling point of water, thus avoiding the necessity for removing water present in the membrane in a conventional pre-annealing treatment step. These polybenzimidazole membranes find particular utility in reverse osmosis desalination processes. The annealing step of the present invention improves the mechanical and separative properties of the membrane and is simple in comparison to conventional annealing procedures.

Abstract: A high Young's modulus poly-p-phenylene-terephthalamide fiber having a unique fine-structure and excellent properties, including excellent resistance to lateral stress and to friction. The fiber is made by extruding an anisotropic dope in a non-coagulating layer, passing the extrudate through a coagulating layer, washing and drying the resulting coagulated fibers in the absence of substantial tension, and heating the fibers under tension.

Abstract: Shaped articles composed of polymers formed from residues which are not melt processable characterized in that the shaped article has been formed from a readily processable melt of a copolymer containing said residues together with in-chain temperature labile residues and has been subsequently heated to remove the labile constituents with recombination of the resultant polymeric residues. Preferably the processable melt should be in the form of an anisotropic melt so that the shaped article may be in oriented form prior to removal of the residues. Typically the shaped articles are articles of thin section composed of p-hydroxybenzoic acid residues.

Abstract: Video disc caddies are treated to maintain dimensional stability by heating them while preventing either inward or outward bowing of the caddy halves for a time sufficient to stress-relieve the plastic.

Abstract: A method is disclosed for substantially reducing shrink back of thermosetting materials from electrical cable. The method comprises reheating the cable, after curing of the thermosetting material and cooling of the cable, to a temperature below the melting point of the thermosetting material.

Abstract: The heat-strengthening of yarn spun from optically anisotropic melt-forming polyesters can be accelerated by coating the yarn prior to heat treatment with certain inorganic compounds.

Abstract: The invention provides a method of heat-treating a biaxially oriented polyolefin film by constraining the film against shrinkage, heating the constrained film to at least the minimum stress relaxation temperature of the polyolefin, and thereafter cooling the treated film to a temperature below the alpha-relaxation temperature of the polyolefin.The film is preferably heated rapidly to the required temperature and cooled rapidly therefrom. The resultant films exhibit good modulus and thermal shrinkage characteristics. The heat-treatment may be supplemented by a conventional heat-setting operation to improve heat-sealing characteristics of the treated films.

Abstract: A method is disclosed of pretreating a plurality of high temperature heat set yarn bundles, e.g. polyester, that have different heat histories but are otherwise identical, to enable said yarns to be dyed uniformly. The method comprises measuring the pre-melt crystallization temperature of each polyester yarn bundle and thereafter heat treating each yarn bundle at a uniform temperature that is at least the same as or higher than the highest measured pre-melt crystallization temperature. Also disclosed are a method of uniformly dyeing polyester yarn bundles that are treated in a plurality of high temperature heat setting units and a method of determining the evenness of the internal temperature of high temperature heat setting apparatus.

Abstract: A process for making a film of butene-1 homopolymer and copolymers of improved strength and clarity and the film made thereby. Such a film is produced by quenching an extruded poly(butene-1) homopolymer or copolymer while in the amorphous state, preferably at temperatures below O.degree. C., and biaxially stretching the quenched film before substantial crystallization occurs. Subsequent heat setting of the film at a temperature above the stretching temperature, but below its melting point, produces a heat stable film of high break strength and clarity, suitable as a food wrap or food container overwrapping material.

Abstract: Spherulites are grown in such sections as neck, neck end, and bottom center or bottom periphery of a hollow bottle-shaped container of biaxially oriented-blow molded polyethylene terephthalate where the resin is not substantially subjected to orientation, thereby to improve the thermal resistance, stiffness and content resistance of such sections to almost the same extent as the biaxially oriented sections of the container such as shoulder and cylindrical sections thereof. The aforesaid sections of the preformed piece before being blow-molded or of the blow-molded container where the resin is not substantially subjected to orientation are first heated at 120.degree.-180.degree. C. for 3-8 minutes and then annealed at room temperature, with a result that such sections have a spherulite texture of an increased density and are opacified to white or milky white.

Abstract: Spherulites are grown in such sections as neck, neck end, and bottom center or bottom periphery of a hollow bottle-shaped container of biaxially oriented-blow molded polyethylene terephthalate where the resin is not substantially subjected to orientation, thereby to improve the thermal resistance, stiffness and content resistance of such sections to almost the same extent as the biaxially oriented sections of the container such as shoulder and cylindrical sections thereof. The aforesaid sections of the preformed piece before being blow-molded or of the blow-molded container where the resin is not substantially subjected to orientation are first heated at 120.degree.-180.degree. C. for 3-8 minutes and then annealed at room temperatures, with a result that such sections have a spherulite texture of an increased density and are opacified to white or milky white.

Abstract: A stretched acrylic sheet which is to be formed into a vision panel at an elevated temperature has its major surfaces reheated to an elevated temperature to intentionally generate a class of surface formations thereon for subsequent removal by polishing prior to the formation of the final vision panel. Such surface deformations are otherwise undesirably generated during vision panel formation and detract from the optical quality of the final product.

Abstract: Removal of haze from plastic articles made of cellulose acetate butyrate, such as light polarizing sunglass lenses made of cellulose acetate butyrate and polyvinyl alcohol, is accomplished by immersing said plastic articles in a substantially water-free bath composition at least 70 weight percent of which comprises an active solvent and a carrier solvent, the former being methyl alcohol, ethyl alcohol, propyl alcohol, butyl alcohol, or any mixture thereof, and the latter being ethylene glycol, glycerol, tricresyl phosphate, butyl phthalate, or any mixture thereof. Preferred values of the relative proportions of the active solvent and the carrier solvent are in the range of 90-5 and 10-95 weight percent, respectively, and more preferably, 80-10 and 20-90 weight percent, respectively.

Abstract: Solvent resistant halogenated aromatic polyester fibers are prepared by heat treating the fibers at substantially constant length at a temperature of from about 270.degree. to about 295.degree. C. for from about 5 to about 60 minutes. The heat treated fibers have improved solvent resistance in that they are capable of withstanding 5 to 20 minute immersions in the commercial dry cleaning solvent perchloroethylene which is at a temperature of from about 60.degree. to about 70.degree. C.

Abstract: A stretch-staging method is disclosed for straightening continuous fiber columns impregnated within a resin-based tape material to increase the strength and reliability of the material. The tape material is supported about the circumference of a half-cylindrical fixture and separated therefrom by a thin lubricating film to reduce surface friction. Loads of substantially equal weight are longitudinally applied at opposite ends of the tape material about the fixture, and the combination is heated in an oven to an elevated temperature for a predetermined period of time thereby stretching and staging the tape material so that distorted fiber columns are straightened and retained in a straightened condition as the resin is advanced.

Abstract: Solvent resistant halogenated aromatic polyester fibers are prepared by first heat treating the fibers at substantially constant length at a temperature of from about 270.degree. to about 295.degree. C. for a period of from about 5 to about 60 minutes, and then further treating the fibers with perchloroethylene which is at a temperature of from about 80.degree. C. up to its boiling point for a period of at least about 15 minutes to produce halogenated aromatic polyester fibers having improved solvent resistance.

Abstract: A method is provided for producing a sintered zirconia article excellent in thermal shock resistance and high in sintered density. The method comprises mixing zirconia powder as the starting material and a stabilizing agent with a definite amount of partially stabilized zirconia powder, shaping and sintering the mixture, and heat treating it under specific temperature conditions.

Abstract: A row of continuous slide fastener coupling elements is in the form of a filamentary coil or zigzag made of thermoplastic synthetic resin. Each coupling element includes a coupling head, a pair of legs extending from the coupling head, and a connector located remotely from the coupling head and extending between one of the legs and a leg of an adjacent coupling head. The connector is heat-set intensely by being heated concentratedly for increased dimensional stability. A method of manufacturing a row of such continuous slide fastener coupling elements includes the step of heating the connectors at a temperature close to the melting point of the monofilament.

Abstract: A powder blend consisting essentially of precursors of a single antiferroelectric compound of lead-barium-lanthanum-zirconate titanate doped with silver, includes at least 0.7 mole percent bismuth permitting a near-full reaction to be achieved at calcining in the low temperature range of 1000.degree. C. to 1130.degree. C. A body is formed of the pulverized calcined material, which body is then sintered in a closed container at 1100.degree. C. Residual PbO remains in the body rendering it conductive. The body is annealed in open atmosphere at 950.degree. C. to drive out the free PbO providing an excellent dielectric having an unusual combination of high K and low TCC.

Abstract: A method of annealing a PTC conductive polymer composition comprising a mixture of two crystalline polymers. Compositions having improved electrical characteristics are obtained by annealing at a temperature between the melting points of the two polymers, preferably closer to the melting point of the lower melting polymer. Particularly useful results are obtained when the annealing method is applied to a self-limiting heater in which the PTC core comprises carbon black dispersed in a mixture of polymers, one of which has a melting point of at least 160.degree. C., preferably at least 200.degree. C., e.g. a mixture of polyvinylidene fluoride and an ethylene/tetrafluoroethylene copolymer.

Abstract: The invention provides a method of heat-treating a biaxially oriented polyolefin film by constraining the film against shrinkage, heating the constrained film to at least the minimum stress relaxation temperature of the polyolefin, and thereafter cooling the treated film to a temperature below the alpha-relaxation temperature of the polyolefin. The film is preferably heated rapidly to the required temperature and cooled rapidly therefrom. The resultant films exhibit good modulus and thermal shrinkage characteristics. The heat-treatment may be supplemented by a conventional heat-setting operation to improve heat-sealing characteristics of the treated films.

Abstract: The flatness of compression-rolled plastic film is improved by passing the film under tension over heated rolls, stretching the heated film, setting the stretched film by passing it over a tempering roll, and then cooling the set film by passing it over a cooling roll.

Abstract: This invention relates to a method of making a tube of thermoplastic material, comprising longitudinal channels of circular cross-section and having such wall stresses that, after axially cutting the tube, the edge parts along the cut edge overlap each other for less than 8% of the outer circumference of the tube.

Abstract: A process for the rapid annealing of refractory fiber is disclosed. Air at a temperature of 750.degree. F. (400.degree. C.) to 1400.degree. F. (760.degree. C.) is passed through a refractory fiber body for a period of 5 to 200 seconds while the body is held securely in place for dimensional integrity. Apparatus for performing the process of this invention comprises an annealing unit containing opposed foraminous platens and means for passing hot air through the platens and through the fiber body retained between the platens or opposed foraminous belts and adjacent conduits and means for passing the hot annealing air through the conduits and belts and through the fiber body retained between the belts. The process and apparatus may be used to produce fiber bodies of a single material or laminated bodies of a plurality of interlocked layers, which may be of different fiber materials.

Abstract: Described herein are self-regulating conductive articles comprised of an extruded length of polymeric material containing not more than about 15% by weight conductive carbon black, the resistivity of the extrudate following prolonged exposure to temperatures in excess of the crystalline melting point or range of the polymeric matrix in which the black content satisfies the equation:2L+5 log.sub.10 R.ltoreq.45.Wherein L is percent by weight black and R is resistivity of the extrudate expressed in ohm-cm. The articles exhibit room temperature resistivity in the range from about 5 to 100,000 ohm-cm and may be employed, e.g., in heat tracing and thermostating applications.