Abstract: A process for producing a polyhalogenated microporous film having a very narrow pore size distribution and good temperature and chemical resistance. The process involves blending a polyhalogenated copolymer with a polyethyloxazoline utilizing a solvent which is a nonsolvent for the polyhalogenated copolymer but a solvent for polyethyloxazoline, forming a film from the blend, drying the film, heating the film to a temperature at or above the melting point of the polyhalogenated copolymer and under conditions such that the microparticulate particles at their points of mutual contact will neck together to form a relatively continuous matrix and extracting the polyethyloxazoline from the film utilizing a solvent for the binder particle to form a microporous film.

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: Paint-coated polymeric films which are bonded to substrates such as automobile panels, as a substitute for spray painted finishes, often develop surface blemishes or defects from the coating or web handling operations. These can be reduced or eliminated by vacuum thermoforming the film to the desired substrate in a plural stage procedure. The periphery of the film is clamped in a frame. Then the film is preheated to a temperature above its glass transition temperature until the film becomes taut in the frame. It is allowed to cool and is then reheated to at least the glass transition temperature and is then vacuum thermoformed to the substrate. This procedure eliminates many if not all of the visible surface defects in the thermoformed film.

Abstract: A process for making molded objects utilizes powder injection molding techniques. Powder is mixed with a binder and then cast into a compact. The compact is then subjected to a first debinding step in the presence of a wicking agent under gentle heating. In this first stage, at least 40% of the binder is removed. Additional binder is then removed in a subsequent higher temperature stage to produce a compact which is free of binder and free of cracks.

Abstract: The invention is a process for the production of solid aromatic polyamic acid and polyimide fibers from a wet gel or coagulation bath wet get using N,N-dimethylacetamide (DMAc) solutions of the polyamic acid derived from aromatic dianhydrides such as 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and aromatic diamines such as 4,4'-oxydianiline (4,4'-ODA). By utilizing the interrelationship between coagulation medium and concentration, resin inherent viscosity, resin % solids, filament diameter, and fiber void content, it is possible to make improved polyamic acid fibers. Solid polyimide fibers, obtained by the thermal cyclization of the polyamic acid precursor, have increased tensile properties compared to fibers containing macropores from the same resin system.

Abstract: Melt-spun polyester fibers are taken up in the absence of heat at a speed of 5,000 to 6,000 m/min under conditions that satisfy the following relations (IX) and (X), subsequently heat-treating the fibers for a period of from 0.01 to 0.05 seconds with a heating roller while the length of the melt-spun fibers is held constant with no drawing step being provided between the taking up and heat treatment steps, and finally winding up the heated fibers0.04.ltoreq.L/(SSxd).ltoreq.0.08 (IX)1.0.ltoreq.To.ltoreq.1.5 (X)where L is the distance (cm) between the spinneret and the convergence point, SS is the speed (m/min) of a take up roller, To is the spinning tension (g/d) at a point immediately after the convergence point and D is the filament fineness (d) of the fiber wound up and is within the range of from 1 to 3 d.

Abstract: A process for simultaneously drying and heat treating wet spun fibers of greater than 20 percent water based on weight of dry fiber material supplied continuously in multiple wraps around a pair of rolls in a heated zone, at a tension of 0.2 to 6 grams per denier at the beginning of the zone, with gas jets extending around each of the rolls for about 45 to 180 to direct turbulent gas at a temperature of 200 to 660 C against the fibers under tension in the zone until the residual moisture in the fibers is from 0.5 to 10 percent water based on weight of dry fiber material.

Abstract: A method and apparatus forms a plastic part having a shape memory which has been formed to a second shape from an initial shape by the application of pressure to cause molecular orientations which are subsequently fixed by being cooled to a desired temperature and, when subjected to subsequent energy such as heating, will eliminate the molecular orientation and create a restoring force to return the part to the initial shape.

Abstract: A process for producing a polyhalogenated microporous film having a very narrow pore size distribution and good temperature and chemical resistance. The process involves blending a polyhalogenated copolymer having a very small particle size with a binder polymer utilizing a solvent which is a nonsolvent for the polyhalogenated copolymer but a solvent for the binder polymer, forming a film from the blend, drying the film, heating the film to a temperature at or above the melting point of the polyhalogenated copolymer and under conditions such that the microparticulate particles at their points of mutual contact will neck together to form a relatively continuous matrix and extracting the binder polymer from the film utilizing a solvent for the binder particle to form a microporous film.

Abstract: Continuous rod-like molding having a FRP core and an outer skin of thermoplastic resin is shaped by introducing the molding into a passage of a heated die, the passage having a diameter slightly smaller at an exit thereof than an initial diameter of the molding, plasticizing the thermoplastic resin by passing the molding through the passage, thereby removing a part of the outer skin, and solidifying the thermoplastic resin, thereby obtaining a product having a diameter equal to the diameter of the exit of the passage.

Abstract: A method of producing a polyester filament which has a superior combination of tensile, dyeability and shrinkage properties. The method comprises forming a polyester-polyethylene glycol copolymer from a mixture consisting essentially of a terephthalic acid or dimethyl terephthalate, ethylene glycol, and polyethylene glycol, with the polyethylene glycol having an average molecular weight of between about 200 and 1500 grams per mole and being added in an amount sufficient to produce a polyester-polyethylene glycol copolymer in which the polyethylene glycol is present in an amount of between about 1.0 and 4 percent by weight of the copolymer formed; forming filament from the copolymer drawing the copolymer filament; and heat setting the drawn filament.

Abstract: A tube or hollow body of a plastic material having memory characteristics is formed in a mold body having interior undulations or grooves. Pressure is applied to the interior of the plastic tube, while the tube is at a temperature above its softening point, to expand the tube into the configuration of the interior of the mold body. The pressure is maintained while the tube is cooled. After cooling, the tube is extracted axially from the mold body, and is reheated to cause the tube, by virtue of its memory characteristics, to return to the shape it had while in the mold, thereby eliminating the distortion and stretching occurring during removal from the mold. The mold body can be a tubular corrugated casing or stainless steel with a relatively thin wall, which cannot be taken apart. End assemblies are provided to hold and seal the tube ends while the tube is expanded in the mold body, by pressure applied through one of the end assemblies. The preferred plastic material is PTFE (TEFLON).

Abstract: There is provided a method of manufacturing magnetic head sliders comprising the steps of cutting a material block, which may be of sintered ferrite or ceramic material, to form a core block and slider block. A groove is formed in the core block, which is bonded to the slider block using techniques to provide a magnetic gap. Thereafter the core block is machined to form a plurality of head cores, followed by machining the slider block to form in parallel a number of sliders, which are lapped and then sliced into individual magnetic head sliders. To prevent particles of material from the magnetic head sliders from separating from the sliders and causing deleterious effects, such as head crashes, a heat treating process is employed in which the slider block and core block are treated for from 3 to 20 hours at a temperature of from 100.degree. C. to 150.degree. C., at an ambient air pressure of from 1.5 to 5 kg/cm.sup.2 and at a relative humidity of not less than 60%.

Abstract: The invention provides molded polyamide articles and a process for making the same. The molded polyamide articles consist substantially of tetramethylene adipamide units, the articles having an increased crystallinity expressed as a first melting enthalpy which is at least 30 Joules per gram higher than a second melting enthalpy determined after subsequent solidification of the polyamide. The process comprises shaping the polyamide from the melt, cooling the resulting polyamide article, and heat treating the article in an inert gas atmosphere at a temperature of 220.degree. C. for 0.25 to 24 hours.

Abstract: A method for treating porous polytetrafluoroethylene and other types of synthetic materials having low surface tension to render the material suitable for use in bonding to living tissue. The synthetic material is enveloped with a liquid of sufficiently low surface tension to permit the liquid to enter the pores of the material. The liquid has a sufficiently low gas content to enable the liquid to absorb or displace essentially all gas nuclei held in the pores of the material as the liquid fills essentially all pores. After the low surface tension liquid has permeated all pores of the porous material, such liquid is replaced with a solution compatible with the body fluid and in which proteins have a low solubility to render the material suitable for implant. When such material is placed in contact with exposed tissue, an immediate bond is formed which permits implanting the material without the need of sutures to hold the material in place.

Abstract: Improved, stronger poly(arylene sulfide) fibers can be produced by treatment of a crystallizable poly(arylene sulfide) fiber with an organic halide, either before or after annealing. Physical properties, such as density and abrasion resistance, can be increased after said treatment.

Abstract: A process for diffusing and subliming water-soluble and water-insoluble materials into never-dried, shrinkable aromatic polyamide fibers, using steam heated at certain controlled temperatures, within a specially designed treatment chamber and a process and apparatus for treating a tow of shrinkable material.

Abstract: A method for producing a purified polycarbonate resin is disclosed, comprising contacting a solid polycarbonate resin with a fluid comprising at least 70% by weight of carbon dioxide and having a temperature of 30.degree. to 120.degree. C. and a pressure of at least 10 kg/cm.sup.2. The method can effectively remove almost all the impurities contained in the polycarbonate resin within a very short period of time, thereby providing highly purified polycarbonate resin materials which are suitably used in the fields of information, electronic and medical industries.

Abstract: A process for producing almost perfect graphite films and fibers at lower graphization temperatures wherein a film or fiber of a polymer selected from a defined group is subjected to a preliminary heat treatment at a temperature of 400.degree. to 700.degree. C., under tension, in vacuo or in an inert gas, and then heat treating the film or fiber at a temperature of at least 1600.degree. C. in vacuo or in an inert gas, to graphitize the film or fiber. The process can be modified to produce graphite films having excellent electric conductivity and mechanical properties, by heat treating a polymer selected from a second defined group at a temperature of at least 1800.degree. C. in vacuo or in an inert gas, impregnating the film with a binder component, and then heat treating the impregnated film at a temperature of not more than 1400.degree. C.

Abstract: The high speed melt spinning of synthetic polymer fibers is provided with on-line zone heating and cooling by which the strand emerging from the spinneret is initially cooled to an optimum temperature above the glass transition point of the polymer, the maintained near that temperature for a period of time to promote development of desirable fiber properties such as crystallization and crystal orientation, and then finally cooled below the solidification point for take up.

Abstract: According to the present invention an elastomeric grommet includes an axial extending central tubular portion of diameter less than the diameter of the compartment wall opening. A flange portion is integral with the central tubular portion and has a diameter greater than the diameter of the compartment wall opening to limit the extent of insertion of the tubular portion into the compartment wall opening. A retention means, such as a flexible annular lip, is integral with the central tubular portion in axial spaced relation from the flange portion and has a free state dimension which is greater than the diameter of the central tubular portion. The integral retention device is yieldable to permit its insertion and the insertion of the tubular central portion through the compartment wall opening and then returns to its free state condition to retain the grommet in loose fitting relation with the compartment wall.

Abstract: An asbestos-free insulating material suitable for use as a header in molten metal casting. The material is made from a dry mixture comprising lime, siliceous component, delaminated vermiculite or spodumene or lithium aluminate or mixtures thereof, and optionally, wollastonite and organic fiber. The dry mixture is mixed with water to form a slurry, shaped, heated in the presence of steam, and dried to remove free water.

Abstract: An inflatable packer construction where the inflatable elastomer element is; (1) constructed from the same type of rubber compound from end-to-end the rubber is cured differentially from end-to-end so that inflation is from one end to the other end; (2) is constructed of rubber having different characteristics from end-to-end so that the cured rubber will inflate from one end to the other end; (3) is constructed of rubber having a release agent between one end of the rubber and a mandrel so as to release one end of the rubber first from the mandrel upon inflation; (4) is constructed of rubber having different thicknesses from end-to-end so that one end inflates sooner than the other end; or (5) is constructed of rubber with a segment of the length of the element having a releasably confining element.

Abstract: A process for preparing a polymer material having improved oxygen and carbon dioxide barrier properties wherein a heated solution cast film, of a linear alternating polymer of carbon dioxide and at least one ethylenically unsaturated hydrocarbon, is cooled at a selected rate.

Abstract: A process for preparing a melt processed polymer material having improved oxygen, water or carbon dioxide barrier properties wherein a quantity of a linear alternating polymer of carbon monoxide and at least one ethlenically unsaturated hydrocarbon is melt processed to form a film, heated to a temperature ranging from about 2.degree. C. to about 40.degree. C. above the melting point of the polymer, and cooling the heated melt processed film at a moderate rate between about 6.degree. C. and about 10.degree. C. per minute.

Abstract: A system for recovering, selecting and recycling empty containers returned after use which includes two specific sequences. In the first sequence, a container (4) passes a door (2) to remove material of a different type, while the accepted product activates a microswitch (9) for counting and activating a warming device to blow in hot air onto the same material which is thus softened; the container is then pushed between a motor driven heated pressing roll (18) with tension supplied by sliding contacts (22) to carry out a compact and permanent pressing by using pressing-welding points and another inertia roller (19). Knives (24) cooperate with the two rollers to ensure the separation. In the second sequence or selection phase, recovered bodies (29), are applied from hopper (30) and fall onto a feeding system with vibrating canals, to maintain the containers individually; photocells (34) check that no superpositions occur.

Abstract: High modulus, high tenacity fibers of poly-p-phenylene terephthalamide (PPD-T) are manufactured comprising a fiber heat treating process for increasing the inherent viscosity and the crystallinity index of the PPD-T. Never-dried fibers swollen with water of controlled acidity are heated beyond dryness in an atmoshphere having a flow of greater than Reynolds Number 10,000 throughout the duration of the heating.

Abstract: Heat-set woven diaphragms based on polyvinyl chloride, well adapted for the electrolysis of hydrochloric acid, comprise:(a) a combination of warp threads and weft threads woven into a cloth weave and having a number of crossings per square centimeter ranging from 270 to 350;(b) warp threads and the weft threads which comprise a mixture of atactic polyvinyl chloride and superchlorinated polyvinyl chloride;(c) an average thickness of from 0.5 to 0.7 mm; and(d) high creasing resistance.

Abstract: By compressing and heat curing a non-resilient, non-flexible recurable material formed by subjecting cured polyimide foam to the action of pressurized steam, a wide variety of useful articles may be produced. These include tough, flame-resistant plastic films, sheets, panels, boards, and shapes in general; composites (both reinforced and unreinforced); and laminates and other articles in which separate shapes or parts are bonded together by a new type of tough, flame-resistant adhesive. Additionally, heretofore worthless waste products such as the kerf cut away from buns of polyimide foam during the foam manufacturing process can be converted and vastly upgraded into any of such an array of new articles of manufacture such as those just mentioned.

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

Abstract: A shaped and drawn aromatic imide polymer article, for example, a film or filament, is produced by shaping an aromatic polyamic acid solution containing an imidizing agent in a polar organic solvent while simultaneously imidizing a portion of the aromatic polyamic acid to an extent such that the resultant self-supporting precursory article contains 20% to 87% by weight of a volatile substance and has a tensile strength of at least 1.5 kg/mm.sup.2 and an ultimate elongation of at least 30%, by drawing the precursory article at a draw ratio of 1.3 or more and by heat-treating the drawn article at a temperature of 150.degree. C. or more.

Abstract: A hot press device has a pair of hot press rollers for heating and pressing a treatment object therebetween while rotating, and pairs of delivery rollers are arranged before and after the pair of hot press rollers. The treatment object passes back and forth through the pair of hot press rollers, and a controller controls the delivery rollers so that the circumferential speeds of the respective delivery rollers located downstream in the forward or reverse passing direction of the treatment object can be increased.

Abstract: In a process for producing an aromatic polyester fiber by heat-treating a fiber obtained by melt-spinning an aromatic polyester exhibiting anisotropy in its molten state, an aromatic polyester fiber having high strength and high modulus of elasticity can be produced with suppressed fusion between single filaments during the heat treatment by (a) subjecting the fiber obtained by melt spinning to heat treatment in an organic liquid heating medium or (b) adhering to the fiber obtained by melt spinning at least one member selected from the group consisting of suspensions having a concentration of 0.05 to 20% by weight of organic polymer powders having a melting point or a softening temperature higher than the heat treatment temperature, and suspensions having a concentration of 0.1 to 20% by weight of barium sulfate powder or barium titanate powder, and then subjecting the resulting fiber to heat treatment.

Abstract: Machined steel blocks 1 and 2 have ridges 20 facing valleys in the opposite block. Polypropylene tape 3 to be heat-treated has sliding contact transversely over each ridge on each block. The blocks are heated by heaters 4. The gap between the blocks is adjustable to suit the material being processed. The gap is large enough so that the tape passing between the blocks is not constrained to deflect from coplanarity by more than its own thickness.

Abstract: A textile sheet structure which is irreversibly highly deformable is prepared by weaving or knitting a yarn which has a degree of elasticity under a load of 5 cN/tex of less than 50% and which consists at least in part of partially oriented, undrawn synthetic filaments which have birefringence values above 20.times.10.sup.-3, elongations at break between 70 and 200% and flow stresses of at least 6 cN/tex, which have been produced by high-speed spinning and are then subjected to a heat treatment under stress at temperatures between 100.degree. and 180.degree. C.

Abstract: A screen unit for a screening machine comprises a screen layer which is bonded to a screen frame spanning an opening thereof. The screen layer is uniformly heated before such bonding is effected so that cooling after bonding generates a tension in the screen layer to allow it to have a trampoline or drumhead vibratile action. The tension is maintained by a reinforcing frame embedded in the frame body.

Abstract: A nonwoven web is prepared by the method of forming a nonwoven web from a composition composed of at least one thermoplastic polymer and at least one defined siloxane-containing additive, which method involves the steps of (A) forming fibers by extruding a molten thermoplastic composition through a die; (B) drawing the fibers; (C) collecting the fibers on a moving foraminous surface as a web of entangled fibers; and (D) heating the web at a temperature of from about 27.degree. to about 95.degree. C. for a period of time sufficient to cause additional additive to move to the surfaces of the fibers. The method of the present invention is particularly useful for the preparation of nonwoven webs, the fibers of which have at least one surface characteristic which is different from the surface characteristics of the polymer component of the thermoplastsic composition.

Abstract: A new method of making an electrically conductive hearth in a d.c. furnace is effected by first heating bricks such as magnesite-graphite bricks and the like, from their new commercially available form to high temperatures decresing the normal resistivity of the bricks and thereafter laying the bricks to form the hearth from top to bottom with the heat treated bricks.

Abstract: Refractory metals or ceramics are diffusion bonded or densified by assembling the workpieces to be bonded, wrapping the assembly with carbon yarn, heating the wrapped assembly, cooling the assembly and unwrapping. The expansion of the workpieces together with the shrinking of the carbon yarn produces tremendous pressures which cause bonding and densifying of the workpiece.

Abstract: A process for treating a strip of film material carrying images in a plane to substantially remove a bend therein includes the steps of forceably positioning a portion of the film material having a bend into a common plane with the film image plane, subjecting the film portion to heat to remove the bend and thereafter allowing the heated film portion to cool.

Abstract: The invention relates to a copolyamide for application in films with improved barrier properties. The copolyamide containing tetramethyleneadipamide and tetramethylene-isophtalamide in a ratio between 9:1 and 1:9 and a relative viscosity of at least 2.0, and a process for the production of the copolyamide. Preferably the copolyamide contains a small amount of a compound that induces the formation of networks between the polyamide chains.

Abstract: A process for preparing a profile of thermotropic polymer having a large cross-section, with improved tensile strength and tensile elasticity moduli, comprising first forming a bundle of fibers or filaments of at least one thermotropic polymer and continuously heating the thus formed bundle to a temperature sufficient to form an anisotropic melt and then passing the anisotropic melt through a shape-giving unit.

Abstract: Ultralight carbon-bonded carbon fiber composites of densities in the range of about 0.04 to 0.10 grams per cubic centimeter are fabricated by forming an aqueous slurry of carbonaceous fibers which include carbonized fibers and 0-50 weight percent fugitive fibers and a particulate thermosetting resin precursor. The slurry is brought into contact with a perforated mandrel and the water is drained from the slurry through the perforations at a controlled flow rate of about 0.03 to 0.30 liters per minutes per square inch of mandrel surface. The deposited billet of fibers and resin precursor is heated to cure the resin precursor to bind the fibers together, removed from the mandrel, and then the resin and fugitive fibers, if any, are carbonized.

Abstract: A process for producing a stabilized yarn for producing a carbon fiber is disclosed. It includes a step for thermally stabilizing a yarn by travelling a continuous fiber through the heated inside of a thermal stabilization furnace. The yarn stabilizing step is characterized in that a tension applied to the continuous fiber at a final stage of stabilizing process is higher than that applied to the continuous fiber at an initial stage of stabilizing process. An apparatus for carrying out the process is also disclosed. According to the present invention, a thermal stabilization fiber having a higher strength and a finer radius can be produced.

Abstract: A process for preparing collagen tubes includes extruding an aqueous gel containing about 1.5% native collagen through a cylindrical spinneret equipped with a central concentric tube designed to receive a part of a coagulation bath, followed by coagulation of the internal and external walls of the tube, leaving the spinneret in a coagulation bath constituted by about 70% acetone and 30% ammonia, followed by drying. Following drying, the collagen tube may be subjected to reticulation by dehydration carried out at about 80.degree. C. under a pressure of about 0.1 mm of Hg (vacuum) for about 24 hours. The reticulated collagen tube may eventually be subjected to a treatment which permits the introduction of azide groups onto the molecule without requiring that the collagen be coupled to any external molecule.

Abstract: Processes for producing semipermeable membranes in the form of hollow fibers are disclosed including extruding a solution of a block copolymer including at least one hydrophilic polymer and at least one hydrophobic polymer while simultaneously injecting a gaseous or vaporous center medium into the center bore of the hollow fiber extrudate, including coagulating the extrudate so formed therefrom. The preferred process includes using air or the components of air as the center medium and employing a polyethyleneoxide-polycarbonate block copolymer to form the hollow fiber membranes.

Abstract: A ceramic body is continuously extruded through a die of an extruder and held on a porous support at a slightly floating state by air pressure jetted from pores of the support.

Abstract: A process for surface modification of oriented polymeric film is disclosed. The process, applicable to polyesters, polyolefins, and polyamides, involves subjecting the film surface to at least one short pulse of intense electromagnetic radiation. Such surface treatment enhances the heat seal adhesion of the oriented polymeric film.

Abstract: A process for preparing an artificial biological membrane in which an aqueous solution containing 6 wt % or more of polyvinyl alcohol having a degree of hydrolysis of not less than 95 mol % and an average polymerization degree of not less than 700 and containing a biological substance or a substance which does not hinder the gelation of the polyvinyl alcohol is subjected to a freezing step followed by a thawing step. Then, the mass thus obtained is further subjected to at least one additional cyclic processing step including the freezing and thawing steps. The product hydrogel is hard or not too soft and not swollen in water.

Abstract: A process for preparing ceramic moldings containing no organic matter with retention of their original shapes which comprises mixing 100 parts by weight of ceramic powders and/or fibers, 0.1 to 50 parts by weight of papermaking organic fibers and/or wet-end additives and 3 to 200 parts by weight of mountain leather, molding the resulting mixture to obtain an unburned molding having enough mechanical strength to withstand molding processings and, subjecting the unburned molding to burning treatment.