Abstract: A method for preparing polyester films, which comprises addition of partially esterified trimellitate at any stage of the polymerization of polyester through direct esterification or ester interchange, the partially esterified trimellitates resulting from salt formation of partial esterified trimellitic acids which are prepared by partial esterification of aromatic tricarboxylic acids selected from trimellitic acid and trimellitic anhydride with alcohols selected from alkyl alcohols and alkylene alcohols. The polyester film prepared the composition has little voids by virtue of good affinity of the particles originating from the partially esterified trimellitates with polyester and thereby not easily broken when forming films. In addition, it is easy to control particle content and size. Further, fine protrusions can be repeatitively formed in the final films, with ease, giving high abrasion resistance and slip property to the film.

Abstract: A method for laminating a porous sheet 1 and a coarse mesh reinforcing material 2 which includes an adhesive layer and is reinforced by drawing, by heat pressing with that adhesive layer in between, in which, (1) the heating temperature during heat pressing is equal to or above the melting point of the adhesive layer and equal to or below the melting point of the porous sheet, (2) a specific relationship is maintained among the difference between the heating temperature and the melting point of the adhesive layer, the difference between the heating temperature and the softening point of the porous sheet, and the heating time, and (3) the unrolling tension of the porous sheet is maintained at 200 to 550 g/mm.sup.2.

Abstract: The invention relates to a composite web comprising one elongated flat composite layer of mutually parallel fibers in a matrix, in which the fibers run at an angle .alpha. (differing from 0.degree.) relative to the lengthwise direction of the web, and which in the lengthwise direction is made up of joined-up and connected web parts. This composite web can be used for continuously producing multi-layer composites. The composite layer of the composite web has no areas with overlap or gaps when placed in a multi-layer composite. The invention also relates to a method for the production of this composite web and of multi-layer composites.

Abstract: Electrically conductive tape yarns of two or more layers comprising thermoplastic polymer resin and electrically conductive particles are prepared by a process comprising extruding a multilayer film containing at least one electrically conductive layer and at least one layer substantially free of electrically conductive particles, quenching the film, slitting the film into tapes and orienting the film before or after slitting.

Abstract: The present invention provides a prepreg obtained by stretching a material including, as a main component, an ultra-high-molecular-weight polyethylene having an intrinsic viscosity of 5-50 dl/g as measured at 135.degree. C. in decalin, to a total draw ratio of at least 20, subjecting the resulting stretched polyethylene material to a splitting treatment, and impregnating the resulting material with a thermosetting resin. The split stretched polyethylene material has improved adhesion to the impregnant resin and can be used as a good base material for prepreg.

Abstract: The biaxially oriented films of high molecular weight polyethylene is formed and its surface modified to provide a hydrophilic property to the resulting film. The film is prepared by melt-kneading the high molecular weight polyethylene with an ordinarily solid hydrocarbon plasticizer and a raw fabric sheet is formed from the resulting molten mixture. After the hydrocarbon plasticizer is extracted the resulting unstretched sheet is stretched under conditions providing a stretched film having a specific surface area of 70 m.sup.2 /g or more and a fibril structure. This stretched film is then heated under standard length constraint conditions to reduce the specific surface area of the stretched film by at least 20 m.sup.2 /g to obtain a biaxially oriented film of high molecular weight polyethylene.

Abstract: The present invention provides a prepreg obtained by stretching a material including, as a main component, an ultra-high-molecular-weight polyethylene having an intrinsic viscosity of 5-50 dl/g as measured at 135.degree. C. in decalin, to a total draw ratio of at least 20, subjecting the resulting stretched polyethylene material to a splitting treatment, and impregnating the resulting material with a thermosetting resin, and a process for producing said prepreg. The split stretched polyethylene material has improved adhesion to the impregnant resin and can be used as a good base material for prepreg.

Abstract: The present invention provides a split polyethylene stretched material having a tensile strength of at least 0.7 GPa when twisted in the range of 50-500 times/m, which material is produced by subjecting a polyethylene having an intrinsic viscosity of 5-50 dl/g as measured at 135.degree. C. in decalin, i.e. an ultra-high-molecular-weight polyethylene to stretching and then subjecting the stretched polyethylene to splitting, as well as a process for producing said material. The split polyethylene stretched material according to the present invention has a large surface area and accordingly can be easily laminated to other materials, and has a high strength and flexibility.

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

Abstract: A para-aramide dope of low degree of polymerization exhibiting an optical anisotropy containing 4-10% by weight of a para-aramide having an inherent viscosity of 1.0-2.5 dl/g and 2-10% by weight of an alkali metal chloride or an alkaline earth metal chloride in a polar amide solvent;a para-aramide fiber obtained by spinning the above-mentioned para-aramide dope of low degree of polymerization;a para-aramide pulp obtained by cutting the above-mentioned para-aramide fiber into a short fiber, mechanically fibrillating the short fiber with a high shearing force and thereafter drying the fibrillated short fiber;a process for producing a para-aramide fiber which comprises adding 0.94-0.99 mole of a para-oriented aromatic dicarboxylic acid halide to 1.00 mole of a para-oriented aromatic diamine in a polar amide solvent in which 2-10% by weight of an alkali metal chloride or an alkaline earth metal chloride is dissolved, carrying out a polymerization at a temperature of -20.degree. C. to 50.degree. C.

Abstract: A process for manufacturing optical fibers includes extruding a transparent thermoplastic plastic sheet having plurality of transversely shaped and spaced parallel grooves extending in the longitudinal direction of extrusion. The thermoplastic sheet is rolled between polished rollers having upstanding circumferential ribs matching the shape and spacing of the grooves in the thermoplastic sheet. The rollers separate the extruded thermoplastic sheet into a plurality of elongated fibers and polish and cool the separated fibers. A preferred embodiment includes a first extruding die extruding said thermoplastic sheet having an index of refraction and a second extrusion die applying a co-extruded coating of plastic having an index of refraction lower than the index of refraction of the transparent sheet. The ribs of the polished rollers form various channel shapes that may produce optical fibers in both circular and non-circular cross-sectional shapes.

Abstract: The objects of the invention are generally accomplished by a method of delaminating imaging materials comprising providing an imaging material comprising donor and receiver elements, heating said imaging material, applying opposed forces to said donor and receiver elements to separate said imaging material into donor and receiver elements, and accumulating the separated donor element. In a preferred method one or both of said opposed forces is vacuum and when the vacuum is released from said donor element, accumulating takes place by spooling after separation.The apparatus for delamination of imaging materials comprises means for applying heat and pressure to said imaging material, means to apply a separating force to at least one of said donor element and receiver element forming said imaging material and means to separate said donor element and said receiver element.

Abstract: An embossed plastic film is made ultra soft and cloth-like by providing a plurality of post-embossed stretched areas along lines that are spaced uniformly across its width and length. The stretched areas are thinner than the unstretched areas. Films also have unique textures and offer cloth-like or non-woven appearances.

Abstract: The objects of the invention are generally accomplished by a method of delaminating imaging materials comprising providing an imaging material comprising donor and receiver elements, heating said imaging material, applying opposed forces to said donor and receiver elements to separate said imaging material into donor and receiver elements, and accumulating the separated donor element. In a preferred method one or both of said opposed forces is vacuum and when the vacuum is released from said donor element, accumulating takes place by spooling after separation.The apparatus for delamination of imaging materials comprises means for applying heat and pressure to said imaging material, means to apply a separating force to at least one of said donor element and receiver element forming said imaging material and means to separate said donor element and said receiver element.

Abstract: A method of making an elastic wrapper netting wherein linear low density polyethylene ribbons are knitted into a Raschel net. The ribbons of the knitted wrapper netting have an orientation of about 1:4.25 in the longitudinal direction.

Abstract: A highly efficient, reliable method is provided for producing an electret filter having an excellent collection efficiency. In this method, a film containing a resin material with high molecular weight is formed and split to form split yarns. The split yarns are then subjected to a charging treatment, and the electret filter is produced from the charged split yarns.

Abstract: The present invention relates to a method of forming shaped articles having a continuous phase of an oriented thermoplastic polymer containing cross-linked polymer microbeads at least partially bordered by void space. The thermoplastic polymer in molten form is mixed with a plurality of the crosslinked polymer microbeads, and the mixture is then formed into a shaped article. The article is stretched in at least one direction to orient it. The orienting conditions and the character and quantity of crosslinked polymer microbeads is effective to form voids in the article at least bordering the microbeads on sides thereof in the direction(s) of orientation.

Abstract: A roller for use in fibrillating oriented films of polyolefin materials having a plurality of pins projecting from the surface of the roller. The pins are distributed in a plurality of rows spaced around the roller surface. The rows each contain about 25 to 34 pins per inch in a space-staggered relationship along two adjacent lines extending along the surface of the roller, either in a linear relationship inclined to a line parallel to the axis or rotation, or in a sinusoidal relationship with adjacent rows being in or out of phase. The roller is rotated and the film is advanced over the rotating roller surface for an arc length of contact of about 30 to 37 degrees to fibrillate the film. The ratio of the surface speed of the roller to the advancing film are controlled to a ratio between from about 1.8:1 to about 2.2:1.

Abstract: A metallized high specular gloss polyethylene plexifilamentary film-fibril sheet with very low emissivity is made by a process of calendering a polyethylene film-fibril sheet between a smooth metal roll and a soft, resilient roll to form a sheet of high specular gloss, followed by vacuum metallizaction of the smooth high specular gloss surface. Such metallized sheets are useful as radiant barriers or roof liners for energy savings purposes.

Abstract: A composite article having controlled void volume and mean pore size comprises:(a) polytetrafluoroethylene (PTFE) fibril matrix, and(b) insoluble, non-swellable sorptive particles enmeshed in said matrix, the ratio of non-swellable sorptive particles to PTFE is in the range of 40:1 to 1:4 by weight, the composite article having a porosity in the range of 30 to 80 percent void volume and a mean pore size in the range of 0.3 to 5 micrometers, preferably with at least 90 percent of pores having a size less than 3.6 micrometers.The article is prepared by incorporating lubricant in the precursor admixture in an amount sufficient to exceed the lubricant sorptive capacity of the particles by at least 3 weight percent and up to an amount at which the mass loses its integrity.

Abstract: A process for making a film including forming a composite material of a thermoplastic film into an annular original film having at least two thick portions according to the inflation process, making the annular original film into a flat shape such that the thick portions are located at substantially opposite ends thereof, and stretching the flat annular original film by clamping the thick portions.

Abstract: Slit film yarn based on propylene polymer, resistant to postfibrillation. The propylene polymer is a block copolymer of propylene and ethylene made up of chain segments consisting of propylene homopolymer and of chain segments consisting of random copolymer of propylene and ethylene.This slit film yarn is suitable for the manufacture of synthetic lawn.

Abstract: A method and corresponding product whereby hydrophobic polyolefin-containing nonwoven materials are provided with sustainable hydrophilic properties for rewet purposes by incorporation into the appropriate spin melt composition an effective amount of an alkoxylated fatty amine in optional combination with up to 60% by weight of primary fatty acid amide.

Abstract: Disclosed herein is a fibrillated weatherproof web having a network structure, which can be produced with ease and is economical. The web comprises a multilayer composite film composed of at least two layers, one being a first layer (I) made of a first thermoplastic resin and the other a second layer (II) made of a second thermoplastic resin having a melting point lower than the first thermoplastic resin and containing at least 300 ppm of a light resistance imparting agent. A number of slits have been formed in a longitudinal or transverse direction. The web has been oriented at a draw ratio in a range of from 1.1 to 15 times. A nonwoven fabric making use of one or more fibrillated webs of the above sort and processes for the production of the web and nonwoven fabric are also disclosed.

Abstract: This invention relates to a method of making thermoplastic polymeric fibrils by passing an aqueous suspension of powdered thermoplastic polymeric material at high pressure through a two-stage valve assembly of the type conventionally used in liquid homogenization.

Abstract: This invention relates to porous polytetrafluoroethylene (hereinafter PTFE) materials having the property of rapid recovery and a method for producing these materials. The microstructure of the porous PTFE material consists of nodes interconnected by fibrils, substantially all of the fibrils having a bent or wavy appearance. Articles made from these materials are particularly suitable for use in the medical field, but are also useful in other areas such as filtration and fabric applications.

Abstract: A stretch broken fiber reinforced resin tow is formed from resin reinforced with continuous filaments by tensioning the two while heating it to a temperature sufficient to soften the resin in the tensioning zone to break all of the filaments in a random manner.

Abstract: A uniaxially drawn oriented polyolefin film for cable insulation, has a thickness of 80 to 250.mu. and is composed of a crystalline polyolefin having a melt index of 10 or more and 0.5 to 20 phr of unsintered polytetrafluoroethylene, wherein the added unsintered polytetrafluoroethylene is in the form of microfibrous particles uniformly dispersed in the crystalline polyolefin as a matrix so as to be parallel to the orientation axis of the polyolefin; an apparent MI value of the film is 1/4 to 1/10 of the MI value of the crystalline polyolefin used; the tensile Young's modulus of the film in the direction of the orientation axis is 2.times.10.sup.4 kg/cm.sup.2 or more; and the change in the thickness of the film in dodecylbenzene at 100.degree. C. is 10% or less. A method for manufacturing this film is also provided.

Abstract: A method for preparing a perforated film, for use in the field of sanitary, food packaging and industrial materials, by thermally embossing an oriented polyolefin film with an embossing roll having a large number of protruding knobs and a pinch roll which presses the film against the knobs, and simultaneously taking up the resultant film at a rate not less than the processing speed of the embossing roll.

Abstract: Electrode materials containing active material in a fibrillated polymer binder are formed continuously into a cohesive electrode component by utilizing a barrel for processing the electrode materials. A mechanism is provided in the barrel for axially advancing the electrode materials, while mixing and kneading the materials to fibrillate the polymer binder. A forming means at the end of the barrel receives the resultant mixture and continuously forms a cohesive component of fibrillated polymer binder and active material as other electrode materials continue to be advanced and processed in the barrel.

Abstract: A process for producing a semi-interpenetrating polymer network of polytetrafluoroethylene and silicone elastomers is described which comprises the steps of (1) intimately blending a mixture of a major amount of unsintered and unfibrillated particulate polytetrafluoroethylene dispersion resin and minor amounts of (A) a hydrocarbon liquid and (B) an addition curable silicone composition consisting essentially of a polydiorganosiloxane having alkenyl unsaturation, an organohydrogenpoly-siloxane crosslinking agent, a catalyst for promoting crosslinking of said polysiloxane, and an inhibitor for the catalytic reaction; (2) forming said blend into an extrudable shape; (3) biaxially extruding said blend through a die into a shaped extrudate product having a randomly fibrillated structure; (4) evaporating said hydrocarbon liquid, and activating said catalyst so as to generate a cured silicone elastomer and polytetrafluoroethylene semi-interpenetrating polymer network comprising said fibrillated extrudate structure.

Abstract: Disclosed is a method of making shaped articles including a continuous polyester phase having dispersed therein microbeads of cellulose acetate which are at least partially bordered by void space, the microbeads of cellulose acetate being present in an amount of about 10-30% by weight based on the weight of said polyester, said void space occupying about 2-50% by volume of said shaped article. Articles made by this method have excellent physical properties, especially optical properties, and are useful in such applications as paper substitutes, for example.

Abstract: A method is provided for heating fibrillated polyolefin film prior to crimping, to improve the crimping, and thus the yield and variability as a filter, of the tow. The fibrillated tow is crimped while still hot from the heating step. The resulting fibers have more uniform crimping at higher levels than those not subject to heating.

Abstract: A process for producing a porous film having practically sufficient mechanical strengths, good flexibility, uniform fine pores and high moisture vapor permeability, and further an extremely thin porous film, which process comprises blending 30 to 80 parts by weight of an inorganic fine powder having a specific surface area of 15 m.sup.2 /g or less and an average particle size of 0.4 to 4 .mu.m with 20 to 70 parts by weight of a polyolefin resin, followed by melt-molding the resulting blend into a film and then stretching the film to 2 to 7 times the original length at least in the uniaxial direction.

Abstract: A gas-permeable porous film which is prepared by stretching a film made from a mixture containing a polyolefin resin and an inorganic filler at least uniaxially and possesses a rugged pattern on its surface. One process for producing the film comprises forming the aforesaid mixture into a film, providing on the surface of the film a rugged pattern, stretching the resulting film at least uniaxially, and forming on the stretched film thus-formed a rugged pattern by means of a heated emboss roll and simultaneously allowing the stretched film to contract.

Abstract: A melt spun film or tape of a thermoplastic fibre-forming polymer comprising spaced fibrils fo the polymer which are substantially aligned to the longitudinal axis of the film. Such aligned, spaced fibrils being interconnected to each other in a random manner.

Abstract: Apparatus, a method for extruding and expanding tubular products of polytetrafluoroethylene (PTFE) and the products produced thereby are provided. In the apparatus, at least one helical groove is placed in the wall of the extruder tip or die. Preferably, at least one groove is machined in the tip having a pitch angle of 45 degrees and at least one groove is machined in the die having a pitch opposite that (135 degrees) of the tip groove. In the expanded products produced according to the invention, at least one radial position within the wall of a tube substantially all of the longitudinal axes of the nodes are oriented at an angle between about 85 degrees and about 15 degrees with respect to the longitudinal axis of the tube.

Abstract: A method of making apertured films including the step of perforating films of thermoplastic materials with embossing rolls engraved with patterns which form small slits or incipient slits in the sheet. The patterns are such that the design on the roll includes lands, or raised areas, which cross lands of the opposing roll at an acute angle. The perforated or partially perforated film formed may then be further processed by orientation, uniaxial or biaxial, simultaneous or sequential; by heat treatment; or both to modify the porosity, hole size, or other properties as desired.

Abstract: A vapor permeable and liquid impermeable microporous film suitable for diaper back sheets and other disposable applications is produced by abrading a filled, unoriented film by passing it through at least one set of at least two cooperating nip rollers, each having an abrasive grit surface.

Abstract: Normally "dry" or hydrophobic polymers, such as polyolefins, polyesters and the like are rendered more moisture absorptive to improve "breathability" by providing an adherent surface of a hydrophilic polymer. Composite fibers are obtained by stretching a laminated or coated structure of a hydrophobic polymer film and a hydrophilic polymer film, longitudinally dividing the stretched film into a plurality of strips and fibrillating the stretched strips. Alternatively, the film can first be subdivided into the plurality of longitudinal strips and then stretched and fibrillated. In the resulting shaped articles (e.g. fibers), a discontinuous, discrete, adherent covering of the hydrophilic polymer component is provided on a core or substrate composed of the hydrophobic polymer. For example, the moisture regain of high density polyethylene fibers can be increased to more than 1%.

Abstract: A gas permeable porous film which is prepared by stretching a film made from a mixture containing a polyolefin resin and an inorganic filler at least uniaxially and possesses a rugged pattern on its surface. One process for producing the film comprises forming the aforesaid mixture into a film, providing on the surface of the film a rugged pattern, stretching the resulting film at least uniaxially, and forming on the stretched film thus-formed a rugged pattern by means of a heated emboss roll and simultaneously allowing the stretched film to contract.

Abstract: A thermoplastic nonwoven web is softened by stretching the web in the cross-machine direction, stretching the web in the machine direction, and shearing the surfaces of the web relative to each other. The resulting web has increased flexibility and increased surface nap which correlates with increased perceived softness.

Abstract: Novel porous fibers and filaments are prepared from normally solid, thermoplastic, orientable, organic polymers which have reactive or reactable groups pendent from the polymer chain, employing a process which involves reactions of said pendent groups while the polymer is in an oriented condition. One of the preferred polymers is a copolymer of ethylene/acrylic acid.

Abstract: This invention relates to a method for producing large area, controlled, uniform deformation of polymeric films which retards premature fracturing. The method includes a deformation step. Sulfonating and annealing the sulfonated deformed film are optional treatments of the method. Deformation can be achieved using pressing, peeling or rolling techniques. The deformed film is sulfonated utilizing sulfuric acid or fuming sulfuric acid.The product obtained using the inventive method results in a deformed film which has improved flow and entrance pressure characteristics compared to non-deformed film materials. The product can be used as a microfiltration membrane, ultrafiltration membrane or filter for various gas, vapor or liquid mixtures. The film may also serve as a porous substrate or other media for other types of fluid separation or purification.

Abstract: The invention relates to a net composed of a regular array of longitudinal ribbon-formed continuous filaments of a polymer substance, and a regular array of transverse stems of different polymer matter, said filaments being embedded in said stems, as well as to a process of producing such net from a sheet consisting of a regular array of longitudinal ribbon-like polymer filaments embedded in a polymer matrix, the filament polymer having a higher melting point than the matrix polymer, by transversely impressing said sheet at a temperature where said matrix is at least semi-molten and the filaments are solid, then splitting the structure.

Abstract: Process for the netlike opening of fibrilled polymeric films, said process consisting in conveying to an opening device of the conventional type (based, for instance, on diverging transferring elements and on lateral film pulling elements such as clamps, grippers or pins, which engage the film at its edges and which are fixed on said traverse elements) the fibrilled film of an undulated or corrugated shape, with the front of the corrugations or waves perpendicular to the direction of the transferring motion, so that the length of the film between the lateral consecutive pulling elements be in excess with respect to the distance between said elements, wherefore said excess will compensate the longitudinal shrinkage that the film will suffer during the transversal opening.

Abstract: An in situ fiberization apparatus for continuously fiberizing belt shaped substrates by impregnation with fibrous material formed from fiber forming polymer solutions. The apparatus includes a belt substrate which is continually passed through a fiber forming solution at a constant rate. During passage of the substrate belt through the fiber forming solution, the apparatus provides continual oscillation of the belt. The oscillating or reciprocating motion of the belt substrate produces the conditions for flow-induced crystallization of fibers around and throughout the substrate material to thereby produce a fiber reinforced substrate.

Abstract: A method for producing a fabric item comprising the steps of producing a perforated substrate in the shape of the desired fabric item, supplying fibers to the perforated substrate, causing the fibers to engage the perforations in the substrate, and retaining the fibers in the perforations.

Abstract: In order to produce a biaxially orientated mesh structure using a single axis draw, a plastics material starting material has parallel, side-by-side main zones separated by lines of holes or depressions; the starting material is drawn parallel to the main zones, stretching the main zones into continuous, orientated main strands 4 interconnected by smaller cross-section strands 6 which have been formed from the zones between holes or depressions in each line, and have been orientated at right angles to the direction of drawing by the effect of the main zones decreasing in width as they were stretched. The mesh structure is suitable for cross-lamination.

Abstract: A process for the preparation of soft porous sheets, comprises forming into a sheet a composition comprising (i) 40 to 80% by weight of an inorganic filler and (ii) 60 to 20% by weight of a polyolefin type thermoplastic elastomer composition comprising at least 50% by weight of a polyolefin type thermoplastic elastomer substantially free of a polar group, in which the tensile stress at a temperature of 25.degree. C. under 100% stretching (100% modulus) is 10 to 100 Kg/cm.sup.2, the elongation at break under stretching is at least 100% and the permanent strain under 100% stretching is less than 50% and up to 50% by weight of a thermoplastic plastomer, and stretching the sheet at a temperature lower than the softening temperature of the polyolefin type thermoplastic elastomer. A porous sheet obtained according to this process has a good combination of flexibility, air permeability and water resistance.