Abstract: The invention relates to an apparatus for manufacturing multifilament threads with at least one hot-air module 6 for drawing or relaxing the thread Y. To manufacture multifilaments with particularly high strength and to avoid the problems of the bearings of the rollers 9, 10 in the hot-air modules 6, at least one apparatus is provided for screening the hot stream of air from the rollers 9, 10, 10' of the or each hot-air module 6. Such apparatus may, for example, take the form of divider sheets 12. To facilitate the introduction of the thread Y into the hot-air module 6, it may be furthermore provided according to the invention that two rows of rollers 9, 10 facing each other are arranged in the or each hot-air module 6, at least the rollers 10 of one row being arranged in the direction of the rollers 9 of the other row and movable beyond these so that a meander-shaped arrangement of the thread Y can be achieved automatically in the hot-air modules 6.

Abstract: A PTFE fiber that is adapted to be sewn at high speeds. The fiber has a toughness greater than about 0.36 grams per denier (g/d). A range for the toughness is from about 0.36 to about 1.01 g/d, with a preferred range being from about 0.50 to about 0.80 g/d. The toughness of the inventive PTFE fiber is most preferably about 0.60 g/d. The inventive fiber has a peak engineering stress greater than about 1.6 g/d and a break strain greater than about 15.5 percent. A preferred range for the peak engineering stress is from about 3.0 g/d to about 5.0 g/d, and a preferred range for the break strain is from about 20 percent to about 50 percent. Most preferably, the peak engineering stress is about 4.4 g/d, and the break strain is about 24 percent. In another aspect, this invention provides a process for making a fiber that involves providing a PTFE fiber and heating the PTFE fiber to a temperature of from about 300.degree. C. to about 500.degree. C.

Abstract: A process for producing polyolefin materials is disclosed which comprises the steps of (a) preparing a molded article of an ultra-high-molecular-weight polyolefin having a viscosity-average molecular weight of more than 500,000; (b) stretching said article by more than thirty-fold; (c) contracting the thus stretched article to an extent ranging from 0.3 to 80% in the direction of stretch; and (d) re-stretching the thus contracted article. The resulting polyolefin materials are improved in mechanical strength and elasticity modulus.

Abstract: A method and apparatus for tentering nonwoven webs during annealing. The nonwoven web of thermoplastic fibers is restrained on a tentering structure at a plurality of tentering points distributed across an interior portion of the web, rather than just along its edges. The nonwoven web is annealed while restrained on the tentering structure to form a dimensionally stable nonwoven fibrous web, dimensionally stable up to at least the heatsetting temperature. The annealed nonwoven fibrous web is then removed from the tentering structure. In one embodiment, the tentering structure restrains the nonwoven fibrous web in a non-planar configuration during the annealing process. The tentering structure includes a plurality of tentering points projecting distally from a tentering support. The tentering points are positioned to be engaged with an interior portion of the web, thus restraining the web during annealing.

Abstract: A method for making linear materials for fasteners, particularly monofilaments, which possess pearly luster and retain this pearly luster intact even after being dyed. A polyester, particularly polyethylene terephthalate, is blended with 1 to 10% by weight of polypropylene and the resultant blend is subjected to melt spinning. The undrawn filament thus obtained possesses pearly luster and can be used as a raw material for fastener parts presenting an appearance of high quality. The undrawn filament has the dyeability thereof adjusted without noticeably affecting the degree of shrinkage when it is drawn at a temperature in the range of from 70 to 98.degree. C. Thus, the monofilaments for fasteners, which possess pearly luster and are allowed to be dyed in colors harmonized with the colors of fastener tapes, can be produced.

Abstract: An oriented splittable film which contains nylon and meta-xylylene adipamide at a weight ratio of 40-85:15-60 and which was oriented with a magnification above 2.8 times in both directions of MD and TD. Examples of nylon include nylon 66, nylon 6-66 copolymer and so on. Under this manufacturing method for an oriented splittable film, when a raw film is heated in a biaxially orienting process, such as the tubular method, the heating temperature at the side part of the film, in the direction of film width,,when folding the bubbles, is controlled along the circumference direction of the bubbles so that it is lower than the heating temperature of the part of the film which is used later as a product.

Abstract: The method of making polystyrene foam for foam products which comprises utilizing atmospheric gases as the blowing agents or preferably mixing one or more of these gases and a blending agent which is non-volatile at the extrusion temperatures, introducing the mixture to a molten thermoplastic polystyrene resin containing nucleating agents such as sodium bicarbonate and citric acid and extruding the thermoplastic in the form of a foam. The resultant foam has substantially no residual blowing agent, is dimensionally stable at ambient temperatures and when used with a non-volatile blending agent can be made with small amounts of blowing agent permitting cooling of the melt without high loading on the extruder. The foam may be coextruded with one or more layers of thermoplastic film so that the resultant product is adapted for use for plates, cups, food containers or packaging and for labels for containers such as glass and plastic containers and for labels that are shrunk in place on a container.

Abstract: A method to remove during fabrication of a flexible electrostatographic imaging member, the curl from a curled layered member having a top surface and a bottom surface and comprised of a substrate and a thickest coated layer including: (a) heating a section of the curled layered member to at least the glass transition temperature of the thickest coated layer, thereby defining a heated layered member section containing a thickest coated layer section and a substrate section; (b) compressing the top surface and the bottom surface of the heated layered member section to expand the thickest coated layer section beyond the dimensions of the substrate section; and (c) cooling the heated layered member section such that the expanded thickest coated layer section shrinks to about the dimensions of the substrate section.

Abstract: A novel composite high-nitrile fiber in which the polymers are arranged in a sheath core type configuration. One polymer of the composite filament contains a solventless, waterless, melt-processable acrylonitrile olefinically unsaturated polymer and the other polymer of the composite filament contains an organic polymer. Either polymer can be employed as the sheath or the core component of the composite filament.

Abstract: An improved process for preparing a biaxially stretched thermoplastic film, such as polyethylene naphthalate (PEN) or polyethylene terephthalate (PET) film, having low thermal shrinkages by simultaneous biaxial stretching of the film in a tenter frame using linear electrical motors to drive the tenter clips. The film is relaxed in the machine direction (MD) and the transverse direction (TD) by converging the paths of the tenter clips and decelerating the tenter clips during heat-setting to provide film having tailored levels of MD and TD shrinkages.

Abstract: Properties of cellulosic membranes such as the length and the ultrafiltration rate are stabilized by warmth/humidity conditioning, whereby temperatures in a range of about 30.degree. to 60.degree. C. and relative humidities in a range of about 10 to 60% are suitable. The membranes may be enveloped at a relative humidity of about 40 to 60% and at about 20.degree. to 25.degree. C. in a packaging which is at least substantially impermeable to the passage of moisture before being subjected to the conditioning.

Abstract: A multilayer polyester film, and a method for making the same, is provided. The film consists of alternating layers of polyethylene terephthalate and polyethylene naphthalate. Biaxial orientation and subsequent restrained heat setting of these materials results in thin films with tensile moduli in both stretch directions well in excess of the values obtained with monolithic films of either material. In some embodiments, a slippery surface is imparted to the film without the use of conventional slip agents.

Abstract: This invention discloses an improved process for manufacturing polyester monofilaments in the diameter range 0.1 mm to 0.3 mm with monofilament properties designed for use as the load-bearing, machine direction filaments in papermakers forming fabrics. The properties of the polyester monofilaments of this invention include a high tensile modulus, a low shrinkage, and control of monofilament diameters within .+-.3%. Process steps include the use of low viscosity polyester granules of Intrinsic Viscosity between 0.5 and 0.6, granules with crystalline skins and amorphous interiors, a low extrusion temperature, and spinneret orifices of cross-sectional area 30% larger than prior art. 1,000 kilograms of polyester monofilaments of uniform diameter may be produced using this improved process without changing the spinneret.

Abstract: Synthetic fiber that are capable of spontaneously transporting water on their surface satisfy the equation(1-X cos .theta..sub.a)<0,wherein.theta..sub.a is the advancing contact angle of water measured on a flat film made from the same material as the fiber and having the same surface treatment, if any,X is a shape factor of the fiber cross-section that satisfies the following equation ##EQU1## wherein P.sub.W is the wetted perimeter of the fiber and r is the radius of the circumscribed circle circumscribing the fiber cross-section and D is the minor axis dimension across the fiber cross-section,and wherein the uphill flux value of said fiber is from 2 to 60 cc/g/hr when measured from a reservoir of synthetic urine test fluid along a 20 cm long ramp to an absorbant on an attached platform at 10 cm height.

Abstract: We have discovered a process for producing a suture from copolymers of glycolide and .epsilon.-caprolactone comprising the steps of (a) extruding a melted copolymer of a glycolide and .epsilon.-caprolactone resin through an orifice and rapidly quenching the melted copolymer resin to produce a filament; (b) drawing the filament in the range of from about 4.times. to about 7.5.times. to produce a singly drawn filament; (c) drawing the singly drawn filament in the range of form about 1.times. to about 3.times. in a first heated zone being maintained at a temperature in the range of from about 150.degree. F. to about 450.degree. F., to form a doubly drawn filament; (d) shrinking the doubly drawn filament in the range of from about 0.75 percent to about 0.98 percent, in a second heated zone being maintained at a temperature in the range of from about 100.degree. F. to about 400.degree. F., to form a relaxed filament then rack annealing the relaxed filament to form a glycolide/.epsilon.-caprolactone suture.

Abstract: Electrically conductive thermoplastic fibers are made by spinning a fiber having an electrically conductive sheath of thermoplastic polymer formulated with carbon black and a non-conductive core from the thermoplastic polymer; quenching the fiber after said spinning to a temperature below the melting point of the thermoplastic; drawing the quenched fiber at a draw ratio between about 2.0 and about 3.2; and, after drawing, relaxing the fiber at a temperature below the melting point of the thermoplastic but above its glass transition.

Abstract: The method of making polystyrene foam for foam products which includes utilizing atmospheric gases as the blowing agents or preferably mixing one or more of these gases and a blending agent which is non-volatile at the extrusion temperatures, introducing the mixture to a molten thermoplastic polystyrene resin containing nucleating agents such as sodium bicarbonate and citric acid and extruding the thermoplastic in the form of a foam. The resultant foam has substantially no residual blowing agent, is dimensionally stable at ambient temperatures and when used with a non-volatile blending agent can be made with small amounts of blowing agent permitting cooling of the melt without high loading on the extruder. The foam may be coextruded with one or more layers of thermoplastic film so that the resultant product is adapted for use for plates, cups, food containers or packaging and for labels for containers such as glass and plastic containers and for labels that are shrunk in place on a container.

Abstract: A polyester support prepared by the step of subjecting a polyester film to bulk rolling and heating the bulk rolled polyester film to a temperature of from 50.degree. C. to the glass transition point of said polyester film, or subjecting a polyester film to bulk rolling at a temperature of from 50.degree. C. to the glass transition point of said polyester film, resulting in the polyester support, wherein the glass transition point of said polyester film is 90.degree. to 200.degree. C., and wherein the step of bulk rolling has a start tension of 3 to 75 kg/m per unit width of the polyester film and an end tension of 3 to 75 kg/m per unit width of the polyester film.

Abstract: We have discovered a process for producing a polypropylene suture including the steps of (a) extruding melted polypropylene resin through an orifice and rapidly quenching the melted polypropylene resin to produce a filament; (b) drawing the filament in the range of from about 5.times. to about 7.5.times. to produce a singly drawn filament; (c) drawing the singly drawn filament in the range of form about 1.times. to about 2.5.times. in a second heated zone being maintained at a temperature in the range of from about 30.degree. C. to about 160.degree. C., to form a doubly drawn filament; (d) shrinking the doubly drawn filament in the range of from about 0.75 percent to about 0.95 percent, in a second heated zone being maintained at a temperature in the range of from about 100.degree. C. to about 180.degree. C., to form a polypropylene suture.

Abstract: A process for preparing a biaxially oriented thermoplastic resin film which comprises: extending a thermoplastic resin sheet in a longitudinal and a transverse directions to form a film thereof, and heat treating the film under a temperature gradient descending from both edges to the center of the film along the transverse direction within a zone defined by the following formula (1) by employing a heater which is located over the film with an angle .theta. of the following formula (3) from said both edges to the center of the film to produce a thermoplastic resin film having uniform physical end chemical properties in the transverse direction:0.25.ltoreq.L.sub.1 /W.ltoreq.0.9 (1)tan.theta.=W/2L.sub.1 (3)wherein:L.sub.1 is the distance from the end point of the transverse extending to the end point of the heat treating; andW is the total width of the film.

Abstract: The invention provides a process for producing a highly absorbent, high strength wiper, which includes the steps of providing a bonded nonwoven web selected from the group consisting of spunbond fiber webs and staple fiber webs, stretching the nonwoven web by applying a stretching tension in at least one direction, aperturing the nonwoven web while maintaining the stretching tension, and relaxing the apertured web, thereby returning the apertured nonwoven web substantially to its pre-stretched dimensions, wherein the process is conducted at a temperature below the softening point of the nonwoven web. The invention also provides a nonwoven wiper produced in accordance with the production process.

Abstract: A coupled spin-draw process for making a fully-oriented nylon yarn including extruding molten nylon polymer with a selected RV through a spinneret and cooling to produce a yarn. The yarn is withdrawn from the quench zone with a feed roll rotating at a speed of at least 4500 mpm. The process further includes cold drawing followed by relaxing the yarn using a steam intermingling jet and then winding up.

Abstract: A biaxially oriented polyester film with excellent levelling property is produced by the inventive process which comprises: (a) melt-extruding and extending biaxially a polyester resin to shape it into a film; (b) treating the film thermally under a condition that formulae (1), (2) and (3) are satisfied; and (c) relaxing the film at a temperature range of Tm-60.degree. C. to Tm-140.degree. C. during the step (b):Tm-60.degree. C.<T1<Tm-10.degree. C. (1)50<T1-T2<100 (2)5<(T1-T2)/t<25 (3)wherein:Tm represents the melting point of the film (.degree.C.),T1 represents the initial temperature for the thermal treatment of the film (.degree.C.),T2 represents the terminal temperature for the thermal treatment of the film (.degree.C.), andt represents time for the thermal treatment (sec.).

Abstract: A method of producing self-texturing filaments that exhibit a desirable tendency to coil rather than to bend sharply or zig zag. The method includes directing a quenching fluid at extruded hollow filaments of a liquid polymer predominantly from one side of the hollow filaments to thereby produce hollow filaments with different orientations on each side. Thereafter the temperature of the hollow filaments is raised to a temperature sufficient for the filaments to relax, but less than the temperature at which the filaments would shrink. When the relaxed filaments are cut into staple lengths, they tend to assume a form that provides a favorable degree of mechanical entanglement that is useful in forming resilient solid structures.

Abstract: Polyester filaments of high shrinkage and high shrinkage tension may be prepared by heat treatment of undrawn crystalline filaments of low shrinkage and shrinkage tension, and may be used for making polyester yarns of mixed shrinkage and bulky polyester yarns and fabrics therefrom.

Abstract: A novel process and novel apparatus for producing prestretched plastic film is presented. The method and apparatus are capable of forming a film from molten material and cooling the film to a non-molten condition so the film can be stretched. The cooled film is engaged and passed through a primary nip and second nip to plasticly and elastically stretch the cooled film to cold orient the film such that the film is stretched beyond the material's yield point. The cooled film is engaged with a plurality of idler rollers at a relatively low tension over a distance sufficient to allow the cooled film to relax to recover a major portion of its elastic deformation. Thereafter, the film is formed into a roll prior to being affixed to a unit.

Abstract: An apparatus for delivering and depositing groups of continuous threads or filaments, which are conveyed by means of a gas flow and which are introduced substantially parallel into a passage having a corresponding cross-section is proposed, the gas flow accompanying the threads upon entering the upper part of the passage is accelerated to high speed and is then decelerated and the threads are deposited on a moving depositing surface. The gas flow delivering the threads flows at high speed through the passage preferably provided with parallel walls and then is decelerated by the suction of part of the gas in the lower passage area laterally through openings in the passage walls.

Abstract: A thermoplastic resin film at least oriented in the transverse direction with minimized bowing phenomenon is provided. The thermal shrinkage stress in the transverse direction of the film satisfies the following formula I, and the thermal shrinkage factor of said film in the transverse direction at a temperature that is 40.degree. C. higher than the glass transition temperature of said resin is 5% or less:(.sigma..sub.2 /.sigma..sub.1).ltoreq. 1.0 (I)wherein .sigma..sub.1 is the thermal shrinkage stress (kg/mm.sup.2) of the film in the transverse direction at a temperature that is 70.degree. C. higher than the glass transition temperature of said resin, and .sigma..sub.2 is the thermal shrinkage stress (kg/mm.sup.2) of the said film in the transverse direction at a temperature that is 80.degree. C. lower than the melting temperature of said resin.

Abstract: A method is disclosed of producing self-texturing filaments that exhibit a desirable tendency to coil rather than to bend sharply or zig zag. The method comprises directing a quenching fluid at extruded hollow filaments of a liquid polymer predominantly from one side of the hollow filaments to thereby produce hollow filaments with different orientations on each side. Thereafter the temperature of the hollow filaments is raised to a temperature sufficient for the filaments to relax, but less than the temperature at which the filaments would shrink.

Abstract: A thermoplastic film web is subjected to a defined shrinking in a treatment apparatus with two mirror-symmetrically arranged tentering chains. For this purpose, each chain is equipped with tentering clamps that have a variable on-center spacing or pitch in the travel direction of the tentering chains, and which additionally are position adjustable in a direction other than the travel direction. The entire clamp body or clamp elements may be position variable in a direction other than the travel direction. In operation, the pitch is first reduced in the inlet and/or heating zone of the treatment apparatus. Simultaneously, the clamping position of the individual clamps or clamping element is changed, e.g. by tilting or lifting. The clamp position change takes up extra film web length resulting from the pitch change, whereby the film web assumes throughout its width a corrugated configuration. Then, the film web is cross-stretched.

Abstract: The invention provide an improved polyethylene terephthalate photographic film base having excellent dimensional stability, optical clarity and mechanical strength while also possessing a crystalline configuration that enables finishing by cutting, chopping or perforating techniques at reduced fracture resistance with decreased generation of dirt.

Abstract: The invention refers to a method for the reduction of the sag and/or of the different stress profile of a flattened tubular film web produced by a blown film process and made of thermo-plastic synthetic resin, transversely to its longitudinal direction. For the solution of the problem to provide a method according to which the sag and/or the different states of tension transversely to the tubular film web can be easily reduced or eliminated to a maximum degree, the tubular film web is heated along its width and then cooled and/or stretched. Furthermore, the invention refers to an apparatus for carrying out the method.

Abstract: Polyester filaments of high shrinkage and high shrinkage tension may be prepared by heat treatment of undrawn crystalline filaments of low shrinkage and shrinkage tension, and may be used for making polyester yarns of mixed shrinkage and bulky polyester yarns and fabrics therefrom.

Abstract: A composite elastic filament with a rough surface, consisting of a sheath component composed of a fiber-forming thermoplastic polymer, such as polyamide, polyester or polyolefin, and a core component composed of a fiber-forming elastomer, such as polyurethane or polyester elastomer, wherein the core/sheath conjugate ratio ranges from 1/1 to 100/1 by cross-sectional area and the core portion has a smooth peripheral surface uniformly extending in the direction of the filament axis while the sheath portion covering the core portion has numerous ridges rising along the circumference of the filament and closely spaced along the length of the filament. This filament can be readily produced by the melt conjugate spinning of the core and sheath components at the above-specified conjugate ratio, followed by drawing 1.1- to 10.0-fold and relaxation.

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 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: Thermoplastic monofilament sutures having improved flexibility and handling characteristics are obtained by a melt spinning process which includes the step of drawing the filaments in a heated zone maintained at a temperature above the melting temperature of the filament. The resulting monofilament sutures have a higher elongation and lower modulus than comparable monofilament sutures obtained without the heated drawing step, and are characterized by a crystalline structure which is more highly ordered in the core of the monofilament suture than in a surrounding annular area.

Abstract: An in situ stabilizing tool provides a stress relieved, ceramic green sheet for green sheet screened stability. A green sheet stablilization system uses air bearings as a means of conveying a continuous ceramic green sheet web in a frictionless and stress free state. Solvent vapor stabilization of green sheets in a continuous mode adjusts solvent concentration in the air bearing using a solvent bubbler. Solvent vapor is generated from a group of solvents (e.g. hydrocarbons, water, etc.) that can be vaporized and used to solvent plasticize the ceramic green sheets to achieve stress relaxation. Take up loops and sensors adjust for longitudinal shrinkage during the green sheet relaxation process.

Abstract: A heat recoverable, shrink-object is made from a mesh or web assembly having thermoplastic threads that extend in a first direction, and second threads that are essentially non-stretchable and run transversely to the first threads, that assembly is embedded in a polymer matrix which is then crosslinked; the thermoplastic threads do not crosslink; the matrix with embedded mesh or web is then heated to a temperature above the crystallite melting point of the polymer matrix and the thermoplastic threads are stretched into an elongated state at that temperature, and the stretching is maintained during subsequent cooling until a lower temperature including room temperature is reached and stretching is no longer needed to maintain said elongated state.

Abstract: Air-jet texturing with drawing, especially cold-drawing, or hot-drawing or other heat-treatments of spin-oriented crystalline polyester filaments, and particularly polyester feed yarns, that have been prepared by spinning at speeds of, e.g., 4 km/min, and have low shrinkage and no natural draw ratio in the conventional sense, provides useful technique for obtaining uniform drawn filaments of desired denier and thereby provides improved flexibility to obtain air-jet textured filaments and yarns of various denier. The resulting yarns have useful properties that are improved in certain respects.

Abstract: A method for preparing a biaxially stretched polyether ether ketone (PEEK) film having excellent precision in thickness, insulating properties and heat shrinkage from an amorphous PEEK film which includes a first stretching step of roll-stretching the amorphous PEEK film in a temperature range of from 50.degree. C. to (Tg-10).degree. C. in a stretching ratio of from 150% to 350% in the progress direction of the film while a necking phenomenon is caused in the film; a second stretching step of stretching the film in the temperature range of from Tg to 170.degree. C. in a direction at right angles to the stretching direction in the first stretching step in a stretching ratio of from 150% to 350%; and a heat set step of thermally setting the stretched film at two stages in the temperature range of 210.degree.-330.degree. C. and the temperature range of 180.degree.-210.degree. C.

Abstract: An improved process for making high tenacity polyamide yarn of the type including the coupled steps of spinning, drawing the yarn at least about 5.OX in stages, the final draw stage employing final stage draw rolls which are heated to above about 200.degree. C., relaxing the yarn by advancing the yarn onto at least one tension letdown roll, and winding up the yarn. The improved process includes heating the yarn tension letdown roll to above about 200.degree. C., rotating the tension letdown roll at a peripheral speed which is at least about 11% less than the peripheral speed of the final stage draw rolls, and contacting the yarn between the final stage draw rolls and the tension letdown roll with tension control means for increasing the tension on the yarn advancing onto the tension letdown roll.

Abstract: A process of expanding plastics film is disclosed, together with an apparatus for performing that process, in which expansion of the plastics film is performed under the control of a liquid providing a stable hydraulic mass, by the downward extrusion and drawing of the plastics film, and the final expansion thereof, exclusively under the influence of the static and dynamic pressure of a hydraulic mass, at a position spaced downwardly of the extrusion head, the hydraulic mass being one that remains in a liquid phase at all temperatures encountered during the step of lateral stretching of the plastics film, to the exclusion of vaporization of the hydraulic mass.

Abstract: A-type fibers having a fiber thickness of less than 1 denier is produced by the steps of: obtaining undrawn fibers by melt-spinning a co-polyester having an intrinsic viscosity of from 0.35 to 0.50, and having repeating units composed mainly of ethylneneterephthalate that contains from 0.5 mol % to 7.0 mol % of 5-sodiumsulfoisophthalic acid and from 0.5 mol % to 10 mol % of isophthalic acid; and flow-drawing the undrawn yarn at a draw ratio of more than 5 times. The A-type polyester fibers are further neck-drawn at a draw ratio of more than 1.05 times to be B-type fibers, and the B-type fibers are subjected to a restricted contraction treatment to be C-type fibers. Staple fibers having a length of less than 15 mm obtained from at least one of the A, B and C-type fibers are blended in a material for the production of a wet type non-woven fabric at a ratio of more than 10 weight %, if necessary, together with other fibers such as a regular type polyester fiber, wood pulp or a glass fiber.

Abstract: A method and apparatus for continuous casting of polymerizable materials that shrink during polymerization includes rapidly heating a moving matrix substantially uniformly throughout its cross section by radio frequency energy to initiate polymerization and maintaining the matrix thereafter in substantial thermal isolation such that substantially adiabatic polymerization occurs.

Abstract: Biaxially oriented film is post-treated by an annealing process in a limited temperature range of 45.degree. C. to 120.degree. C. for various time periods based on the temperature for annealing in order to produce a film having less than a 0.2% shrinkage in the machine direction as measured at 51.7.degree. C. for 24 hours. This film has a wide range of uses, such as overwrapping film.

Abstract: A process for the manufacture of a crimped polyester yarn obtained from a polyester partially-oriented yarn comprising fabricating a partially-oriented polyester yarn by a high-speed process, cooling the partially-oriented polyester yarn, cold drawing the cooled yarn, and subjecting the cold drawn polyester yarn to a thermal treatment under tensionless conditions or under controlled overfeed conditions.

Abstract: A biaxially oriented polyester film simultaneously satisfying the following formulas (I) to (III):.vertline.S.sub.180 -S.sub.120 .vertline..ltoreq.54 (I)T.sub.S.sup.MD .gtoreq.100 (II)Q.sub.120 .ltoreq.0.7 (III)wherein S.sub.180 is shrinking stress (g/mm.sup.2) of the film in the machine direction at 180.degree. C., S.sub.120 is shrinking stress (g/mm.sup.2) of the film in the machine direction at 120.degree. C., T.sub.S.sup.MD is shrinkage initiation temperature (.degree.C.) of the film in the machine direction, and Q.sub.120 is shrinkage (%) of the film in the machine direction after 5 hours' treatment at 120.degree. C., is described. The film has a good dimensional stability due to its low shrinkage, particularly in the machine direction, and substantially free from defect such as wave and wrinkle.It is prepared by biaxially stretching, heat-setting and relaxing an extruded polyester film under particular conditions so as to obtain a biaxially oriented polyester film having these characteristics.

Abstract: A process for improving the properties of fibers of a copolymer of ethylene terephthalate/hexahydroterephthlate units with a high proportion of hexahydroterephthalate units by a 2-stage drawing, crimping, relaxing process to provide stretchy filaments of high elongation accompanied by low shrinkage.

Abstract: A biaxially oriented polyester film simultaneously satisfying the following formulas (I) to (III):.vertline.S.sub.180 -S.sub.120 .vertline..ltoreq.54 (I)T.sub.S.sup.MD .gtoreq.100 (II)Q.sub.120 .ltoreq.0.7 (III)wherein S.sub.180 is shrinking stress (g/mm.sup.2) of the film in the machine direction at 180.degree. C., S.sub.120 is shrinking stress (g/mm.sup.2) of the film in the machine direction at 120.degree. C., T.sub.S.sup.MD is shrinkage initiation temperature (.degree.C.) of the film in the machine direction, and Q.sub.120 is shrinkage (%) of the film in the machine direction after 5 hours' treatment at 120.degree. C., is described. The film has a good dimensional stability due to its low shrinkage, particularly in the machine direction, and substantially free from defect such as wave and wrinkle.It is prepared by biaxially stretching, heat-setting and relaxing an extruded polyester film under particular conditions so as to obtain a biaxially oriented polyester film having these characteristics.