Abstract: Provided is a thickness variation adjustment-type air ring capable of accurately and optimally controlling the volume of cooling air at all positions in the circumferential direction, and stably manufacturing a synthetic resin film having an exceptionally low thickness variation. A thickness variation adjustment-type air ring is provided on a die of an inflation film manufacturing apparatus which locally controls the volume of cooling air discharged from a cooling air passage in a circumferential direction to adjust the thickness variation of a synthetic resin film when blowing the cooling air around a molten synthetic resin tube extruded in a longitudinal direction to cool and solidify the molten synthetic resin tube to form the synthetic resin film, the thickness variation adjustment-type air ring.

Abstract: Methods of producing toothbrush handles having an inner cavity are provided.

Abstract: The present invention relates to a prestretched agricultural stretch wrap film which is used for baling applications when packaging for example grass, maize, sugar beet pulp, malt, straw, household refuse and the like. The prestretched agricultural stretch wrap film according to the present invention is produced by prestretching a polyethylene-containing co-extruded blown film, which comprises at least two layers joined to one another, in the longitudinal direction by at most 70%, so that it still retains an elongation capability in the longitudinal direction of at least 310% or so that a force is to be exerted on said film of less than 6 N in order to stretch the film by 75% in the longitudinal direction.

Abstract: The invention relates to high efficiency solar collection devices having a matte surface, a low refractive index surface, or both, that increases solar radiation transmission into the device. The matte surface is on a thermoplastic and may be provided in many ways, such as by a matting agent, by the use of a matte chill roll, embossing, or other techniques. The matte and/or low refractive index surface may be a coating, film (single or multi-layer) or sheet (single or multi-layer). The invention is especially useful in both rigid and flexible photovoltaic modules.

Abstract: The invention relates to a method for curing of a composite material. The method involves applying heat to only a first region of said composite material, such that said first region is heated to a temperature above the cure onset temperature of said curable resin, thus initiating curing of said curable resin in said first region; and maintaining the composite material in an insulated state, such that the curing of said curable resin spreads to regions of the composite material outside of said first region.

Abstract: The method and the device serve for the blow molding of containers. A preform of a thermoplastic material is first subjected to thermal conditioning in the region of a heating section along a transporting path. Subsequently, the preform is transformed into the container inside a blow mold by the effect of blowing pressure. The thermal conditioning of the preforms is carried out by a number of radiant heaters positioned one above the other. The radiant heaters are activated during production in accordance with a first heating profile and activated during standby mode in accordance with a second heating profile (50), which is different from the first heating profile.

Abstract: An injection blow molding (IBM) system and method for consistently maintaining the surface temperature of the parison molds within a desired range. Implementation of this system/method can result in more consistent production of higher quality parisons and molded articles. Additionally, this system/method reduces the discretion required by the IBM operator and shifts the burden of consistently making high-quality parisons and molded articles onto the designer of the IBM tooling.

Abstract: A continuous multi-layer film includes a support layer having a first film surface, and a hard coat layer, formed on the support layer, having a second film surface, and having a curling tendency in an inward direction. In the decurling method, the multi-layer film is transported. A first transition of the support layer in the multi-layer film being transported into a rubber phase is induced by supplying fluid vapor on the support layer. After supplying the fluid vapor, a second transition of the support layer from the rubber phase into a glass phase is induced. The multi-layer film is transported while a portion of the support layer in the rubber phase is prevented from contacting a solid object. The hard coat layer is formed from a polymer produced from an ultraviolet curable compound, and the support layer is formed from cellulose acylate.

Abstract: A continuous multi-layer film includes a support layer having a first film surface, and a hard coat layer, formed on the support layer, having a second film surface, and having a curling tendency in an inward direction. In the decurling method, the multi-layer film is transported. A first transition of the support layer in the multi-layer film being transported into a rubber phase is induced by supplying fluid vapor on the support layer. After supplying the fluid vapor, a second transition of the support layer from the rubber phase into a glass phase is induced. The multi-layer film is transported while a portion of the support layer in the rubber phase is prevented from contacting a solid object. The hard coat layer is formed from a polymer produced from an ultraviolet curable compound, and the support layer is formed from cellulose acylate.

Abstract: A blow molding machine for blow molding a container having an integrally formed handle; said container blow molded from a previously injection molded preform; said preform comprising a body portion and said integrally formed handle; said machine including a preform loading station at which said preform is oriented by a preform orienting apparatus.

Abstract: A method of molding a large returnable container includes a heat treatment step for subjecting a thick preform formed of a polyester resin or a primary blow-molded article to intermediate blow molding with heating to obtain an intermediate molded article, and a final blow molding step that includes subjecting the intermediate molded article that has shrunk to final blow molding with heating to obtain a large returnable container. The heat treatment step includes disposing the preform or the primary blow-molded article in a heat treatment mold, and pressurizing the preform or the primary blow-molded article so that a shoulder and a body obtained by blow molding close contact to a cavity surface of the heat treatment mold, and are subjected to a heat treatment, the shoulder being heated at a low temperature as compared with the body.

Abstract: The invention relates to a method for the production of sandwich components with an open core structure and a cover layer applied to each side, wherein the cover layers are formed with a curable plastic material, and the sandwich component is cured in a closed device under pressure. A charging gas, which may be nitrogen or air, is introduced to the core structure prior to at least partial solidification of the cover layers, wherein a charging gas pressure p Charging gas is selected that is less than or equal to an operating pressure p operating of the closed device in order to, in particular, at least largely prevent the formation of sink marks in the cover layers. Furthermore, the invention relates to a press for implementing the method.

Abstract: A method for blow molding containers having cross-sections of a non-circular shape from preforms, in which a temperature profile varying at least in the circumferential direction of the preform is produced by means of at least one heat transfer element, for which purpose the preform and at least the heat transfer element are oriented toward one another by a relative rotational movement in the circumferential direction of the preform, the heat transfer element is rotated relative to the stationary preform about a heat transfer element axis during the relative rotational movement. Further, a device for blow molding such containers where the heat transfer element and the holder are rotatable about a heat transfer element axis and are coupled with a rotational drive.

Abstract: For controlling temperature in the molding of plastics, metal, ceramic, or die-casting, a circulator supporting a molding machine includes a fixed displacement pump driven by an electronic servo motor for volumetric metering of thermal fluid to or from the molding machine. A pre-set or dynamically controlled volume and flow rate profile matches the heating and cooling requirement of a molding machine and process. Volumetric metering may be based on parameters such as time, machine cycle status, temperature, pressure, and/or flow rate. Fluid may be circulated through the mold at positive or negative pressure at fixed, variable, or pulsed flow. The supply side in a fluid loop may be restricted so as to cause a pressure drop in or upstream of the mold, die or barrel, and seed bubbles may be injected into the fluid flow to excite vaporization and lowering of the fluid temperature.

Abstract: Biaxially-oriented nylon film according to the present invention is biaxially-oriented nylon film made from nylon. In the biaxially-oriented nylon film, an elongation ratio of the film in each of four directions (an MD direction, a TD direction, a 45 degree direction and a 135 degree direction) until a film rupture is 70 percent or more, the elongation ratio being measured in a tensile test (testing conditions: a sample width is 15 mm; a distance between gauge points is 50 mm; and a tensile speed is 100 mm/min), and a stress ratio A (?1/?2) between a tensile stress ?1 and a tensile stress ?2 in a stress-strain curve obtained in the tensile test of the film is 2 or more in each of the four directions, the tensile stress ?1 being a value at a point where the elongation ratio becomes 50 percent while the tensile stress ?2 being a value at an yield point.

Abstract: A technical problem is to fully make up for a restricted upper limit to the preform body wall thickness. An object is to provide a bottle which is narrow-mouthed and yet has a substantially expanded body. The molding process comprises steps of: (1) injection molding a preform in the shape of a test tube taller than the bottle wherein the preform has a cylindrical mouth opening portion disposed in an upper part of the preform, and wherein the mouth opening portion of the preform serves also as a mouth opening portion of the bottle product; (2) thermally shrinking the preform from an initial height so that portions other than the mouth opening portion of the preform would have a height that is smaller than that of the bottle; and (3) setting this thermally shrunk preform in a blow mold and biaxially drawing and blow molding the preform into the bottle.

Abstract: The invention relates to manufacturing thermoplastic material containers (2) with a petaloid bottom (4) by drawing-blowing hot preforms (16) in a blowing mold that has a petaloid mold bottom (1) including radiating ridges (13) alternating with cavities (11) that are adapted to form the valleys (7) and the feet (5), respectively, of the container bottom; during drawing, heat losses are reduced in longitudinal zones (19) of the end part (20) of the preforms, extending over the bottom (18) and over an axial portion of their body (21), distributed over the periphery of the ends of the preforms facing respective cavities (11) of the mold bottom (1).

Abstract: The invention relates to a method and a device for heating preforms of a thermoplastic material, the preforms, after having been heated, being subjected to a reshaping operation, and microwaves being applied to the preforms, at least during a portion of the period of heating, in a resonator.

Abstract: A method and apparatus for curing a thermosetting material. The method comprises heating the material with a liquid heating medium; measuring an electrical or optical property of the material with a cure sensor; and regulating the temperature of the liquid heating medium in accordance with the measured property of the material.

Abstract: Method and system for making a product (1) having a solid body (2) and having one or more cavities (3, 15) inside that solid body, with a broad surface and a small thickness. A liquid material is provided within a mold (4), and solidification of the liquid material is controlled in a position dependent way from the outside of the product. When using a thermoplastic material, the system may cool said liquid material less in areas that are projections of the cavities on the outside of the product on its broad surface. When using a thermosetting material the system may include means (5, 9) for controlled heating the liquid material, excluding the projections of the intended cavities. Once part of the product has sufficiently solidified outside the intended cavities the liquid material is driven from the intended cavities by means of a fluid. In the product some cavities may be provided with a conductive layer or structure, e.g.

Abstract: A method and apparatus are disclosed for managing thermal energy transfer between a mold, die or cavity and a thermal transfer fluid. The thermal energy being exchanged with the mold, die or cavity is calculated in real time as a function of the temperature differential between inlet and outlet fluid temperatures, the volumetric rate of fluid delivery, and known characteristics of the fluid. The rate of thermal energy exchange is controlled by varying the fluid delivery rate in accordance with a desired thermal energy exchange profile.

Abstract: Process for forming containers from a blank, preferably a preform, made of a thermoplastic, the containers being formed using a stretch-blow moulding machine of rotary type having a blow-moulding mould mounted on the periphery of a carousel rotated continuously about its axis, the blow-moulding mould operating in cyclic manner according to a blow-moulding cycle having the following steps: placing a preheated blank in a blow-moulding mould; closing the blow-moulding mould; blowing the blank in the blow-moulding mould; flushing the inside of the container with a cooling gas, by injecting air thereinto; grasping the blow-moulded container by external gripping means; and opening the blow-moulding mould, which process includes automatically varying the duration of the flushing step at each start of production of the containers, in a temporary and evolving manner for a few minutes to establish in the containers thermal conditions enabling the first containers to be formed at a temperature that gives them a final vo

Abstract: The invention relates to manufacturing thermoplastic material containers (2) with a petaloid bottom (4) by drawing-blowing hot preforms (16) in a blowing mold that has a petaloid mold bottom (1) including radiating ridges (13) alternating with cavities (11) that are adapted to form the valleys (7) and the feet (5), respectively, of the container bottom; during drawing, heat losses are reduced in longitudinal zones (19) of the end part (20) of the preforms, extending over the bottom (18) and over an axial portion of their body (21), distributed over the periphery of the ends of the preforms facing respective cavities (11) of the mold bottom (1).

Abstract: A catheter having an elongated shaft with a tubular member which forms at least a portion of the shaft and which is formed of a biaxially oriented thermoplastic polymeric material, and a method of forming the catheter shaft by radially and longitudinally expanding the tubular member to biaxially orient the polymeric material. A catheter of the invention has an improved combination of low bending stiffness, high rupture pressure, and high tensile strength, for improved catheter performance.

Abstract: A method for blow molding containers having cross-sections of a non-circular shape from preforms, in which a temperature profile varying at least in the circumferential direction of the preform is produced by means of at least one heat transfer element, for which purpose the preform and at least the heat transfer element are oriented toward one another by a relative rotational movement in the circumferential direction of the preform, the heat transfer element is rotated relative to the stationary preform about a heat transfer element axis during the relative rotational movement. Further, a device for blow molding such containers where the heat transfer element and the holder are rotatable about a heat transfer element axis and are coupled with a rotational drive.

Abstract: The process and the apparatus serve for the blow moulding of containers (2). A parison (1) composed of a thermoplastic material is first subjected to heat conditioning along a transport path in the region of a heating section (30). The parison is then subjected to a forming process within a blow mould with exposure to blowing pressure to give heat container. The heat conditioning of the parisons is carried out by a plurality of mutually superposed radiant heaters (41). The blow moulding of the container is followed by wall-thickness measurement at at least one level within the height of the container. The heating power of a radiant heater associated with this height level is controlled. The control system receives a prescribed wall-thickness value as required value and the measured wall thickness as actual value.

Abstract: A preform of injection-molded PET has a body wall thickness of 3.0-4.5 mm. The preform is high-temperature mold-released from an injection cavity mold and an injection core. Pre-blowing of the preform is restricted at 5±0.5 seconds after the mold release, at a temperature of 112-117° C. of the pre-blow mold, and for a pre-blowing time of 0.5-1.0 second. Air blowing is applied to expand only the body of the preform. Stretch blow molding is performed restrictively at 3-4 seconds after the mold release from the pre-blow mold, at a temperature of 103-107° C. of the blow mold, and for an air blowing time of 6-9 seconds, thereby stretch blow molding the preform into a bottle and simultaneously heat setting to impart heat resistance to the bottle.

Abstract: The invention discloses a method of heating a preform (50) of thermoplastic material prior to blow molding the same to form a container, with the preform (50) being held at a threaded region (58) during heating thereof. A neck portion (48) of the preform (50) close to the threaded region (58) is temporarily heated more strongly as compared to other regions. The invention further relates to a tempering device for heating such a preform (50), including at least one radiation and/or heat source acting on the preform (50) and defining several impact regions on the preform (50) with different heating intensities each. The preform (50) has associated therewith at least one reflector (52) disposed in the threaded (58) and/or neck region (48) for deflecting radiation proportions piercing the neck region (48) and for heating the neck region (48) on an inside of the preform (50).

Abstract: Wide panels of UHMWPE having exceptional flatness and surface quality are ram extruded through a slit die equipped with a plurality of individually adjustable cooling zones proximate the panel exit slit and transverse to the machine direction which cool the by a back pressure device and preferably a vertical movement restraint. The process is robust and can be run for long product campaigns.

Abstract: A thermoforming methodology for laminated thermoplastic sheets which preserves the class “A” finish and high gloss thereof. In a thermoforming process including heating followed by vacuum and opposing air pressure application, and then followed by application of chilled compressed air, control of spherulite formation using any of: addition of a nucleating agent to the paint film, using the chilled compressed air at a temperature of substantially about 32° F., heating to no more than about 311° F., selecting a paint film having a high melting point temperature, and selecting a paint film that is non-crystalline.

Abstract: Medical device balloons are formed from a tubular parison by a process or apparatus which establishes a controlled location (initiation zone) on the parison where radial expansion is initiated. Initiation within the initiation zone is achieved by heating the parison in that location to a higher temperature than the remainder of the parison for at least a portion of the blowing time. A variety of apparatus configurations are provided, some of which allow for the size and location of the initiation zone to be readily reconfigured. Balloons can also be modified, post-blowing, using heating apparatus and methods described.

Abstract: A preform of injection-molded PET has a body wall thickness of 3.0-4.5 mm. The preform is high-temperature mold-released from an injection cavity mold and an injection core. Pre-blowing of the preform is restricted at 5±0.5 seconds after the mold release, at a temperature of 112-117° C. of the pre-blow mold, and for a pre-blowing time of 0.5-1.0 second. Air blowing is applied to expand only the body of the preform. Stretch blow molding is performed restrictively at 3-4 seconds after the mold release from the pre-blow mold, at a temperature of 103-107° C. of the blow mold, and for an air blowing time of 6-9 seconds, thereby stretch blow molding the preform into a bottle and simultaneously heat setting to impart heat resistance to the bottle.

Abstract: A method of manufacturing a thermoplastic resin film, comprising the steps of: discharging a molten thermoplastic resin in film form from a die; and conveying the discharged film by a plurality of multi-staged cooling rollers with the discharged film contacting the rollers to cool the discharged film at multiple stages, wherein the temperature of surface of a first cooling roller out of the plurality of cooling rollers provided at multiple stages, the first cooling roller being positioned at the most upstream side in the direction in which the film is conveyed, ranges from the glass-transition temperature (Tg) of the thermoplastic resin?40° C. or higher to Tg+30° C. or lower.

Abstract: An extrusion mold for molding a ceramic membrane having an one-end closed tube structure which is easily integrated and has a high gas separation efficiency, and a fabrication method of a ceramic membrane tube using the same, the extrusion mold comprised of an outer mold, an inner mold and an extrusion hole end cap, wherein the cap has a through hole at its center for controlling an extrusion molding density, and a passage is formed in each of the inner and outer molds for maintaining an inner pressure of an extruded tube to be the same as an outer pressure. The one-end closed ceramic membrane tube is fabricated by supplying a ceramic mixture into the extrusion mold in a state that the end of the extrusion hole of the extrusion mold is closed by the cap, removing the cap after filling the mixture in the end of the extrusion hole, and further supplying the mixture into the extrusion mold to obtain a tubular ceramic extrusion body with a particular length.

Abstract: A catheter having an elongated shaft with a tubular member which forms at least a portion of the shaft and which is formed of a biaxially oriented thermoplastic polymeric material, and a method of forming the catheter shaft by radially and longitudinally expanding the tubular member to biaxially orient the polymeric material. A catheter of the invention has an improved combination of low bending stiffness, high rupture pressure, and high tensile strength, for improved catheter performance.

Abstract: Wide panels of UHMWPE having exceptional flatness and surface quality are ram extruded through a slit die equipped with a plurality of individually adjustable cooling zones proximate the panel exit slit and transverse to the machine direction which cool the by a back pressure device and preferably a vertical movement restraint. The process is robust and can be run for long product campaigns.

Abstract: A resin molding device, resin molding method and resin molded product capable of guiding a sink to an optional position to perform a precise molding. A resin molding metal mold includes a gate formed in the central part of a cavity, a stepped part increasing the opening diameter of the cavity in the circumferential direction orthogonal to the flowing direction of a molten resin introduced into the cavity from the gate, and a fine outside air inlet part circumferentially formed on the outer part from the stepped part. The outside air inlet part is formed of a porous material and allowed to communicate with the outside of the resin molding metal mold through a communicating passage.

Abstract: The present invention relates to a method for making an ablation transducer having a plurality of helical elements that can be operated out of phase to orient the acoustical energy beam forward or backward in the longitudinal direction. The transducers includes a cylindrical inner electrode, a cylindrical piezoelectric material disposed over the inner electrode, and a cylindrical outer electrode disposed over the cylindrical piezoelectric material. Spiral grooves are cut through at least the outer electrode separating the transducer into a plurality of functionally discrete helical transducer segments. The helical transducer segments can be operated independent from one another. An array of intertwined helical transducers arranged linearly along a helical axis are also contemplated.

Abstract: A method of making a finished product includes the steps of providing a feedstock comprising a polymer component comprising 5 to 100 parts by weight of a polymer selected from the group consisting of polyethylene in particulate form, polyvinyl chloride in particulate form, and a mixture of polyethylene and polyvinyl chloride both in particulate form; 0 to 95 parts by weight of polystyrene in particulate form; an extender, and optionally reinforcing fibres or particles; mixing the feedstock with a thermosetting resin selected from an unsaturated polyester resin in liquid form and a catalyst for the polyester resin and an epoxy resin in liquid form and a catalyst for the epoxy resin; and subjecting the product to suitable conditions of temperature and pressure to cause the polyethylene and/or the polyvinyl chloride and the polystyrene, if present, to melt and the thermosetting resin to set to form the finished product, e.g a shutter board.

Abstract: This invention relates to methods and apparatus for manufacturing shaped polymeric articles by substantially continuous vacuum forming. The method includes providing a sheet of hot polymeric material which is disposed onto a rotating belt having a mold impression. Vacuum pressure is applied to the polymeric material through the belt so as to draw the hot polymeric material into intimate contact with the mold impression to form a patterned sheet portion and a remaining sheet portion. This method thereafter cools at least the patterned sheet portion below a heat deflection temperature of the polymeric material, forms the remaining sheet portion, and then cools the remaining sheet portion below the heat deflection temperature so that features other than the central pattern, such as nail and butt edges, can be mechanically worked into the polymeric sheet.

Abstract: A long glass fiber filler reinforced resin material for molding includes a masterbatch formed of a composite of a matrix resin with a polypropylene (PP) component and a long glass fiber filler and a diluent resin made from an ethylene-propylene block copolymer. The above-described matrix resin of the masterbatch includes the PP component having a pentad isotactic index of at least 95%, and a melt flow rate (MFR) of the matrix resin of the masterbatch is 100 to 500 g/10 min and larger than six times a melt flow rate of the diluent resin. The long glass fiber filler is in a content of 30 to 50 mass percent with respect to a total mass thereof.

Abstract: A method of fabricating a formed object, comprising the steps of printing a desired high quality photo or near photo like image on a forming material at a resolution substantially equal to the resolution of an original digital image used to form the high quality image, and forming the formed object by a forming process in which the temperature and pressure across the object are varied.

Abstract: A method of stretching films in which all or a portion of the width of the film is cooled during or just after stretching so as to improve the uniformity of the film. The includes stretching a polymeric film in a tenter that grasps the film with a plurality of clips along the opposing edges of the film and propels the clips to thereby stretch the film. The tenter includes driven clips and idler clips, with at least one idler clip between respective pairs of driven clips. The cooling is done so as to improve the uniformity of the clip spacing relative to the spacing obtained at otherwise identical process conditions without such cooling.

Abstract: Large blow moldings are made from polyethylene of density ??0.94 g/cm3 and of melt flow rate MFR 190/21.6<50 g/10 min, and of notched tensile impact strength azK (?30° C.) not less than 300 kJ/m2 and bursting strength, determined by a drop height test at ?18° C., of more than 3 m. Processes for producing large blow moldings of this type involve annealing large blow moldings after production. The moldings are used for storage and transport of hazardous materials.

Abstract: A thread or other element for bonding fibers in a fibrous reinforcement for use in a fiber composite is such that it is at least degraded in the course of the production of said fiber composite.

Abstract: A method of making a catheter balloon, and a balloon formed thereby, in which a polymeric tube is radially expanded in a mold having a wall with an outer surface and an inner surface defining a chamber, and having at least a section with one or more channels in the wall. The channels result in improved transfer of heat to the polymeric tube within the chamber of the mold during blow molding of the tube to form a balloon, so that the tube is heated more quickly and evenly. One aspect of the invention is directed to a balloon having sections with improved thin walls.

Abstract: A cooling procedure for the manufacture of plastic parts by injection, that uses a gas under pressure that is lodged in the cavity provided by the two mould parts (1, 2) during at least the cooling phase. The cold gas, and its application, covers both coated and non-coated part.

Abstract: A process of manufacturing a sulfoaluminate or ferroaluminate cement, and an apparatus for the manufacture. The cement is manufactured from a mixture containing CaCO3, Al3 and/or Al(OH)3, CaSO4, SiO2 and/or a product containing silica or silicates such as clay, these compounds being present in the anhydrous or hydrated form. In this process, the mixture is treated up to clinkering by movement in a center of a kiln, in a sheet with approximately constant thickness, at approximately constant speed, along a treatment path having a positive temperature gradient, and for a treatment time during which the mixture remains below its melting temperature. The mixture is clinkered to produce a clinkered mixture that is cooled upon exit from the treatment path.

Abstract: A method of preventing delamination of multiple layers of an oriented polymer container having an opening defined by the multiple layers comprising a bi-axially oriented multilayer polymer container having an opening defined by a perimeter at which the multiple layers are exposed; heating the perimeter until workable; providing a curling die; feeding the multilayer perimeter into the curling die to curl the perimeter sufficiently to inhibit delamination of the layers and a container when so made.

Abstract: This invention relates to methods and apparatus for manufacturing shaped polymeric articles by substantially continuous vacuum forming. The method includes providing a sheet of hot polymeric material which is disposed onto a rotating belt having a mold impression. Vacuum pressure is applied to the polymeric material through the belt so as to draw the hot polymeric material into intimate contact with the mold impression to form a patterned sheet portion and a remaining sheet portion. This method thereafter cools at least the patterned sheet portion below a heat deflection temperature of the polymeric material, forms the remaining sheet portion, and then cools the remaining sheet portion below the heat deflection temperature so that features other than the central pattern, such as nail and butt edges, can be mechanically worked into the polymeric sheet.