JP2012211731A - Variable-width nozzle, and tenter oven using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable-width nozzle having high heating or cooling efficiency for a resin film, having sufficient uniformity of a heat transfer coefficient in a resin film width direction and suitably used for a tenter oven.SOLUTION: In order to increase the heating or cooling efficiency of an air injection nozzle used for producing the resin film, it is necessary to increase a flow rate of air blown to the resin film. If air volume is increased by simply increasing rotational speed or others, power consumption of a fan is increased. Accordingly, a nozzle which can be arranged between clip rails in the tenter oven and which has a width varying function compatible with even a change in the width of the film is installed, thereby it becomes possible to bring the nozzle close to the film, to increase the flow speed of the air, and to increase the heat transfer coefficient. However, it was found that although unevenness was alleviated between the nozzle and the film until now, the unevenness of the heat transfer coefficient caused by the shape of the nozzle becomes conspicuous by bringing the nozzle and the film close to each other. Therefore, the variable-width nozzle is configured to include a connecting rib formed at the end of the nozzle by which even if an interval between the nozzle and the film is narrow, the heat transfer coefficient is uniformed.

Description

  The present invention relates to an air jet nozzle used for heating or cooling a resin film and a tenter oven using the same.

  As a method for producing a resin film such as a biaxially stretched polyester film, an unstretched film discharged in a sheet form from a die and cooled and solidified on a cast drum is stretched in a resin film transport direction by a longitudinal stretching machine, and then a tenter. Known are the sequential biaxial stretching method that stretches in the width direction of the resin film in the oven, and the simultaneous biaxial stretching method that stretches the unstretched film in the tenter oven in the transport direction of the resin film and the width direction of the resin film. It has been.

  In the tenter oven used in these manufacturing methods, a plurality of air ejection nozzles provided with air ejection ports on the surface facing the resin film surface are arranged in the direction of transporting the resin film. The air controlled to a desired temperature by the heat exchanger is sent to each air jet nozzle by a fan, and blown from the jet port toward the resin film surface. The blown air is collected from the suction port in the tenter oven by a fan and reused.

  In general, the tenter oven is divided into a plurality of zones such as a preheating zone, a stretching zone, a heat setting zone, and a cooling zone in the direction of transporting the resin film, and is configured so that the temperature of air can be set at least for each zone. The resin film that is gripped and conveyed by the clip is heated to a temperature suitable for stretching in the preheating zone, stretched at least in the width direction in the stretching zone, and then heat-treated or cooled in the heat setting zone or cooling zone. Is done.

  The properties of the resin film produced in this way are affected by the thermal history received when passing through each zone of the tenter oven. Therefore, in order to obtain a resin film having uniform characteristics in the width direction, it is required to make heat exchange between the air ejected from the air ejection nozzle and the resin film uniform in the width direction. A slit nozzle that is one of the air ejection nozzles requires a structure that keeps the slit gap constant in order to achieve the uniformity.

Also, in this tenter oven, a large amount of energy is consumed for heating the resin film, and it is indispensable to reduce the energy consumption of this tenter oven in order to save energy in the film manufacturing process. Film heating in the tenter oven is performed by heat exchange between air and resin film. Generally, in order to increase the heat transfer rate, it is necessary to increase the air flow rate. However, simply increasing the fan's air volume will increase power consumption, pressure loss will increase as the air volume increases, and the discharge pressure will also need to be increased. . In addition, the influence of the outside air flowing into the tenter oven accompanying the film to be put into the tenter oven is also large, and the outside air is low in temperature and requires energy for heating, so it is possible to suppress the inflow of outside air into the tenter. This is important for energy saving in the resin film manufacturing process.
Therefore, it is considered that the heat transfer rate can be increased by making the distance between the resin film usually 100 mm or more and the air ejection nozzle close. However, usually, the resin film and the air ejection nozzle are designed to be as close as possible at the design stage, and it is often difficult to bring them closer from there. Therefore, when looking at the positional relationship of the devices in the tenter, the running rail of the clip for gripping and transporting the film can be moved in the width direction of the film to correspond to the stretching ratio of various films depending on the film type. Rails are arranged between the upper and lower air ejection nozzles. Therefore, if the air ejection nozzle can be installed inside the rail, the film and the air ejection nozzle can be brought closer to each other. If the width of the air ejection nozzle can be changed in the same manner as the movement of the rail so that it can cope with the movement of the rail in the film width direction, it can be brought close to each other. Such an air ejection nozzle with a variable width has been proposed as a variable width nozzle of Patent Document 1. However, the variable width nozzle of Reference 1 is intended for drying, and is not manufactured in consideration of the uniformity of the heat transfer coefficient required for the resin film. A resin film having quality as a product could not be produced due to an increase in thickness unevenness due to unevenness.

Japanese Patent Publication No. 63-33068

  An object of the present invention is to provide a variable width nozzle suitable for use in a tenter oven that reduces the distance between the air ejection nozzle and the resin film, improves the heat transfer rate, and suppresses unevenness in the heat transfer rate due to the proximity. Is to provide.

In order to achieve the above object, the present invention adopts the following configuration.
1) In an air ejection nozzle that blows air on a resin film that is conveyed in one direction, at least two or more of the lengths of the air ejection ports of the air ejection nozzle can be changed in a horizontal direction perpendicular to the film conveyance direction. A variable width nozzle constituted by a movable nozzle, wherein an air outlet of the movable nozzle has a slit shape, and at least one connecting rib for connecting two lips forming the slit at a position other than a side plate A variable width nozzle characterized by having the above.
2) The variable width nozzle according to 1), wherein the connecting rib is attached at a tip of a movable nozzle that is an air ejection port.
3) The variable width nozzle according to 1) or 2), wherein the connecting rib and the two lips are made of a single plate-like member.
4) The variable width nozzle is a variable width nozzle comprising two movable nozzles that can move on a plenum for supplying air to the variable width nozzle, and a fixed nozzle that is fixed to the plenum. The variable width nozzle according to any one of 1) to 3).
5) In the connection rib of the variable width nozzle, the width of the connection rib is 2 mm or less, and the thickness of the connection rib in the vertical direction is 2 mm or less. Variable width nozzle.
6) In the case where there are a plurality of the connecting ribs, the distance between adjacent connecting ribs is 10 mm or more.
7) A tenter oven characterized in that the variable width nozzle according to any one of 1) to 6) is disposed in at least one zone selected from a preheating zone, a stretching zone, a heat setting zone, and a cooling zone. .
8) In the tenter oven, a plurality of variable width nozzles according to any one of 1) to 6) are installed, and the attachment positions in the width direction of the connecting ribs in the plurality of nozzles are parallel to the lip. The tenter oven as described in 7) above, wherein the tenter oven is mounted so as not to overlap on the same coordinates when projected onto the position coordinates.

  According to the present invention, by providing a resin film and a variable width nozzle close to each other, a variable width nozzle suitable for use in a tenter oven having a higher heat transfer coefficient than that of a conventional nozzle and less heat transfer coefficient unevenness is provided. To do.

(A) is the schematic of the variable width nozzle of this invention. (B) is the P section enlarged view of Drawing 1 (a), and is a figure showing one form of a connecting rib. It is a figure which shows the manufacturing method of the nozzle (a) The method of manufacturing from one flat plate, (b) The method of manufacturing from two lips. It is a figure which shows the form at the time of (a) narrow width of the variable width nozzle, (b) widening. It is sectional drawing of the variable width nozzle and plenum in this invention. It is a figure which shows one form of a plenum. It is a figure which shows the (a) horizontal cross section of a plenum, (b) The cross section of the vertical width direction of the air supply port vicinity, (c) The cross section of the vertical width direction in the position away from the air supply port. It is sectional drawing of the tenter oven provided with the variable width nozzle of this invention. It is a figure which shows one of the connection methods of a movable nozzle and a clip rail. It is a tenter outline figure at the time of seeing a tenter from the top. It is a tenter outline figure at the time of seeing a tenter from the side. It is a figure which shows another form from FIG. 1 of the variable width nozzle of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking as an example the case of applying to a manufacturing process of a biaxially stretched resin film by a melt film forming method.

  The present invention provides at least two air jet nozzles for blowing air onto a resin film transported in one direction so that the length of the air jet outlet of the air jet nozzle can be changed in a horizontal direction perpendicular to the film transport direction. A variable width nozzle constituted by the movable nozzle described above, wherein the air nozzle of the movable nozzle has a slit shape, and at least a connecting rib for connecting two lips forming the slit at a position other than the side plate It is a variable width nozzle characterized by having one or more. Here, the “perpendicular horizontal direction” is a horizontal direction on a plane perpendicular to the film transport direction. The “air nozzle outlet of the movable nozzle” is an opening of the movable nozzle that ejects air to the outside of the movable nozzle. In addition, “two lips forming slits” are two flat plates that form an air outlet of the movable nozzle and are arranged in the transport direction.

  Further, the present invention is the variable width nozzle according to the above, wherein the connecting rib is attached at a tip of a movable nozzle that is an air ejection port. Here, the movable nozzle tip refers to the edge portion of the air outlet in the lip forming the nozzle (number 15 in FIG. 1).

  FIG. 1 shows an example of a variable width nozzle 1 according to an embodiment of the present invention. The variable width nozzle 1 includes a fixed nozzle 2 (not essential) and two movable nozzles 3, and is connected to the plenum 4. The plenum 4 is for supplying air to the variable width nozzle 1, and is fastened by a fixed nozzle 2 and a connection surface 11 by a flange (not shown), etc., and the movable nozzle 3 is for moving the connection surface 11 in the width direction. The plenum 4 is connected by a slide rail or the like (not shown).

  Next, the structure of each of the fixed nozzle 2, the movable nozzle 3, and the plenum 4 will be described.

  First, as shown in FIG. 2A, the fixed nozzle 2 is formed by connecting one flat plate 21 with a connecting rib so that the air jet 6 is formed so that the slit width 20 is constant. 5 is cut out by laser machining or the like, and then bent at a predetermined angle with the root of the connecting rib 5 as a fulcrum. Here, by using laser processing with high dimensional accuracy, it is possible to provide a flat air outlet 6 with a slit width 20 on a flat plate, and at the same time, the connecting rib 5 serves to maintain the slit width from an external force. Even after bending, a uniform slit width 20 can be maintained.

Next, the movable nozzle 3 is obtained by performing laser processing and bending processing in the same manner as the fixed nozzle 2 and then closing one end of the movable nozzle 3 with a side plate 7 as shown in FIG. In order to efficiently apply the air supplied to the variable width nozzle to the resin film, one end of the movable nozzle serving as the end in the width direction of the variable width nozzle 1 is blocked so that the air is not blown sideways from the side. It is necessary to make it. (This is an example in which the connecting rib and the two lips are made of a single plate-like member.)
Further, as shown in FIG. 3A, when the width of the variable width nozzle 1 is narrow, a shield plate 8 is attached to the movable nozzle 3 and the outside of the air outlet 10 for supplying air from the plenum 4 to the variable width nozzle 1. The portion is closed with a shielding plate 8 to prevent air leakage and prevent unnecessary air from flowing.
Here, when there is no connecting rib in the movable nozzle 3, there is no reinforcing member at the end portion (open end portion) without the side plate 7 connecting the lips, so that the slit gap cannot be maintained, Necessary uniformity of necessary heat transfer coefficient due to non-uniform wind speed of the blown air, or when the movable nozzle 3 moves, it interferes with the fixed nozzle 2 and generates dust and adheres to the film. There is a possibility that the quality of the resin film cannot be obtained.
Further, the production of the fixed nozzle 2 or the movable nozzle 3 is not particularly limited to the production of a single flat plate, and as shown in FIG. Position the slits formed at the tips of the flat plates to be uniform in width, devise the welded portions of the flat plates 22a and 22b and the groove shape of the connecting ribs to minimize heat input during welding It is possible to manufacture by welding by following appropriate welding procedures, such as, but when the heat input during welding increases, the lip deforms and the fixed nozzle 2 and the movable nozzle 3 interfere to generate dust, It is conceivable that the movable nozzle 3 cannot move, and manufacturing by welding has disadvantages such as high cost and manufacturing time compared to the laser processing method. Better Yes.

  Next, the plenum 4 will be described. The plenum 4 has a shape as shown in FIG. 5, and air is sent from an air duct connected to the air supply port flange 52 to an air supply port 51 a on the side surface of the plenum, and passes through a slit inside the plenum, which will be described later. It is a device that supplies air from the outlet 10 to the variable width nozzle 1 at the top thereof. The structure of the plenum is made so that the wind speed of the air blown out from the slit of the variable width nozzle 1 is uniform, and as shown in FIG. The partition plate 61 is arranged obliquely when the plenum is viewed from above so that the cross-sectional area of the air flow path gradually decreases from the inlet 51a to the other air inlet 51b. Moreover, when the BB 'cross section and CC' cross section of FIG. 5 are seen, it becomes cross-sectional shape like FIG.6 (b) and (c), respectively, and goes to the back from the air supply port 51a. Therefore, the air flow path cross section 65 is small. Further, as shown in FIG. 6 (b), a horizontal partition plate 62 is inserted above the partition plate 61, and folded portions 63 are provided at both ends of the horizontal partition plate 62 in the vertical direction. 4 internal slits 64. As the depth of the air channel section 65 gradually decreases toward the depth of the plenum, and the air passes through the internal slit 64, the uniform wind speed in the width direction of the variable width nozzle 1 can be obtained.

Next, a mechanism for moving the variable width nozzle in the width direction of the movable nozzle will be described.
As shown in FIG. 1, the fixed nozzle 2 and the movable nozzle 3 are combined, and the movable nozzle 3 moves to change the nozzle width. Therefore, it is necessary to move the movable nozzle 3 in the width direction, and the moving mechanism is shown in FIG. FIG. 4 is a cross-sectional view of the variable width nozzle 1 and the plenum 4 in the width direction. The fixed nozzle 2 is fastened and fixed to the plenum 4 by a flange 41 and a bolt 43. The movable nozzle 3 is attached to a slide rail 42 attached to the plenum 4 so that the movable nozzle 3 is accommodated inside the fixed nozzle 2 and moved in the width direction. By doing so, the movable nozzle 3 can move on the plenum 4 along the slide rail (also referred to as guide rail) 42 in the width direction, and the width variable function of the width variable nozzle can be realized. Here, in FIG. 4, the movable nozzle is configured to be accommodated inside the fixed nozzle. However, the movable nozzle 3 may be disposed outside the fixed nozzle 2, and the moving mechanism of the movable nozzle 3 is a slide rail. It is not limited to 42 and is not particularly limited to a slide rail as long as it can move in the width direction such as a moving mechanism using wheels.

  FIG. 11 shows another form of a variable width nozzle composed of two movable nozzles. The variable width nozzle 1a includes two movable nozzles 3a and 3b connected to the plenum 4 by a slide rail or the like (not shown) so that the nozzle width can be changed by moving the movable nozzle 3a or 3b in the width direction. It has become. In this case, the shape of the nozzle ejection part becomes non-uniform, such as the nozzle heights differing between the left and right nozzles, so the air flow in the tenter described later becomes asymmetrical on the left and right, making it difficult to achieve a uniform heat transfer coefficient. 1 is more preferable, but when the influence of the air flow in the tenter on the heat transfer coefficient is small, a variable width nozzle composed of two movable nozzles as shown in FIG. There may be. Two or more movable nozzles may be used from the viewpoint of uniformity in the width direction. The upper limit is not particularly limited, but may be two in terms of uniformity in the width direction and cost.

  Next, the uniformity of the heat transfer coefficient of the variable width nozzle will be described. Here, regarding the uniformity of the heat transfer coefficient, the difference between the maximum value and the minimum value of the heat transfer coefficient is preferably within 20%, but may be larger depending on the film type, and is particularly limited. is not.

  In order to make the heat transfer coefficient in the width direction of the variable width nozzle 1 composed of the fixed nozzle 2 and the movable nozzle 3 uniform, it is important to make the wind speed ejected from the slit uniform. Due to the structure of the variable width nozzle 1, the cross-sectional shapes of the fixed nozzle 2 and the movable nozzle 3 cannot be made exactly the same, but in order to make the wind speed uniform, the cross-sectional shapes are required to be the same as much as possible. Of these cross-sectional shapes, first, it is required that the slit widths from which air is ejected are the same. Further, the movable nozzle 3 is housed inside the fixed nozzle 2, and the cross-sectional shape of the nozzle is maintained in consideration of the fact that each lip is not in contact and the deformation of the nozzle due to gravity and external force due to long-time operation. Reinforcing members are required. The position of the reinforcing member is a structure in which the movable nozzle 3 is accommodated in the fixed nozzle 2, and when the connecting rib is installed at a place other than the slit nozzle tip, the connecting rib and the movable nozzle interfere with each other and the width cannot be changed. At least the fixed nozzle 2 can be provided with a reinforcing member only at its tip. Further, since the movable nozzle 3 and the fixed nozzle 2 are desired to have the same shape as much as possible, it is preferable that the reinforcing member of the movable nozzle 3 is also the tip of the movable nozzle. Therefore, the connecting rib that is a reinforcing member takes these into consideration, and this reinforcing member can be realized by the connecting rib in the present invention (having the function of connecting two lips at the slit nozzle tip), and therefore By the connecting rib installed at the tip of the movable nozzle, the uniformity of the heat transfer coefficient of the variable width nozzle can be realized, and dust generation due to contact between the lips that affects the quality of the resin film can be prevented.

  Here, the structure of the aforementioned connecting rib will be described.

  With the above-mentioned connecting rib, the slit width can be made uniform, and the uniformity of the heat transfer coefficient of the variable width nozzle can be realized, while the connecting rib disturbs the air flow around the connecting rib, It has also been found that heat transfer coefficient unevenness occurs. Therefore, it is preferable that the connecting rib has a shape in which the width of the connecting rib is 2 mm or less and the thickness of the connecting rib in the vertical direction is 2 mm or less. If this range is exceeded, the heat transfer coefficient unevenness will increase and the quality of the resin film thickness may deteriorate, and the rib shape should be optimized for the resin film to be produced. It is desirable to do. Here, the connecting rib width is the dimension in the width direction of the connecting rib as shown in FIG. 1B, and the connecting rib height is the dimension in the vertical direction. In addition, although it is a rectangular parallelepiped shape in this figure, a shape like a round bar may be sufficient and it does not specifically limit to a rectangular parallelepiped shape. In the case of a shape in which the connecting rib width or height changes depending on the position to be measured, the connecting rib width 12 is the smallest width dimension of the width, and the connecting rib height 13 is the smallest of the heights. The height dimension.

  Also, with regard to the installation position of the connecting ribs, if the distance between two adjacent connecting ribs is short, the flow rate of air flowing between the ribs decreases and the heat transfer coefficient unevenness increases. The distance is preferably at least 10 mm. If it is 10 mm or more, the influence of the decrease in the air flow rate flowing between the connecting ribs is small, and there is almost no actual damage to the quality of the resin film. The upper limit depends on the rigidity of the nozzle lip and is not particularly limited, but is approximately 1000 mm or less. Here, the distance between two adjacent ribs means the distance between the centers of adjacent rib widths, as shown in FIG. In order to simplify the manufacturing process of the connecting rib, this is often made at an equal pitch, in which case it corresponds to the connecting rib pitch.

  Next, a tenter using the above-described variable width nozzle 1 and plenum 4 will be described. The variable width nozzle 1 and the plenum 4 are used in a high-temperature furnace surrounded by a furnace wall 71 as shown in FIG. 7 in order to stretch or simply heat-treat the resin film 73 only in the width direction or simultaneously in the width direction and the conveyance direction. The film 73 is vertically installed so as to sandwich the film 73 in the clip rail 72. The air sent out from the circulation fan 74 is supplied to the plenum 4 through the discharge duct 76. The air supplied to the plenum 4 passes through the inside of the plenum, is supplied to the variable width nozzle 1, and is blown onto the resin film 73 from a slit at the tip. The blown air is sucked by the suction nozzle 75, passes through the suction duct 77, is heated by the heater 78 having a filter, and is carried to the circulation fan 74. The above steps are repeated, air is circulated and heated, and the resin film 73 is heated.

  Next, a variable width mechanism when the variable width nozzle 1 is actually installed in the tenter will be described. The clip rail 42 is moved in the width direction according to the width of the resin film to be manufactured. The width variable nozzle 1 must also change the nozzle width according to the width, and the movable nozzle 3 needs to be moved in the width direction. is there. At this time, as shown in FIG. 8, the movable nozzle 3 and the clip rail 42 are fixed to the movable nozzle and connected to the connecting member 81 having a long hole so that the movable nozzle 3 can be moved in conjunction with the movement of the clip rail 42. When the rod-like connecting members 82 fixed to the clip rails are combined as shown in FIG. 7, when the clip rail 42 moves in the width direction, the movable nozzle 3 can be moved following the movement. The rod-like connecting member 82 fixed to the clip rail 42 is heated during the production of the resin film, and the rail extends, and also moves in the transport direction (also referred to as MD direction) by changing the rail width. If 42 is simply connected, the variable width nozzle will be damaged. Therefore, it is necessary to design in consideration of movement in the MD direction, such as making the shape of the hole of the connecting member 81 into a long hole shape corresponding to the amount of rail movement. However, it is possible to install a movable nozzle drive source without connecting the movable nozzle 3 and the clip rail 42. At this time, a function to avoid damage due to interference between the variable width nozzle 1 and the clip rail 42, such as synchronization with the movement of the clip rail, is required.

  Next, the structure of the entire tenter will be described. FIG. 9 is a schematic view of the entire tenter as viewed from above. After the resin film held at the tenter inlet is heated to a predetermined temperature in the preheating zone 91, the width of the clip rail 72 is gradually expanded in the stretching zone 92, and the resin film 73 is stretched in the width direction. Next, it passes through the heat fixing zone 93 and is cooled in the cooling zone 94 to complete a resin film. As shown in FIG. 10, by using the variable width nozzle 1 of the present invention as a variable width nozzle used in a tenter, the heat transfer coefficient is improved as compared with a normal variable width nozzle, and the resin film 73 is formed with a smaller air volume than usual. The temperature could be raised or cooled to a predetermined temperature, and the connecting rib of the variable width nozzle of the present invention could make the heat transfer coefficient non-uniformity into a shape that did not cause any harm to quality.

  Here, the zone in which the variable width nozzle is installed may be any of the preheating zone 91, the stretching zone 92, the heat fixing zone 93, and the cooling zone 94. From the viewpoint of energy saving, it can be installed in all zones of the tenter. Although it is desirable, the cost effectiveness is examined and any one of the zones may be used.

  In addition, when installing a plurality of variable width nozzles in the tenter, the position of the connecting rib is changed for each variable width nozzle, and the mounting position of each connecting rib in the plurality of nozzles in the width direction is parallel to the lip. It is desirable that the projectors are mounted so that they do not overlap on the same coordinates when projected onto position coordinates in various directions. This is because, when the positions of the connecting ribs of a plurality of variable width nozzles are projected on the position coordinates in the direction parallel to the lip, if they overlap on the same coordinates, the resin film 73 passing through the tenter is heated at that position. This is because the transmission rate unevenness increases, heating unevenness occurs, and the quality of the resin film deteriorates.

DESCRIPTION OF SYMBOLS 1, 1a Variable width nozzle 2 Fixed nozzle 3, 3a, 3b Movable nozzle 4 Plenum 5 Connecting rib 6 Air outlet 7 Side plate 8 Air shielding plate 10 Air outlet 11 Connecting surface 12 Connecting rib width 13 Connecting rib height 14 Adjacent Distance between two ribs 15 Movable nozzle tip 20 Slit width 21 Flat plate 22a, 22b Lip 31 Partition plate 32 Horizontal partition plate 33 Turned portion 41 Flange 42 Guide rail 43 Bolts 51a, 51b Air supply port 52 Air supply port flange 61 Partition plate 62 Horizontal partition plate 63 Folded 64 Internal slit 65 Air flow path cross section 71 Furnace wall 72 Clip rail 73 Resin film 74 Circulating fan 75 Suction nozzle 76 Discharge duct 77 Suction duct 78 Filter and air heater 81 Movable nozzle side connecting member 82 Clip rail Side bar-shaped connecting member 91 Preheating zone 92 Stretching zone 93 Heat fixing zone 94 Cooling zone 95 Film width

Claims (8)

At least two or more movable nozzles so that the length of the air ejection nozzle of the air ejection nozzle can be changed in the horizontal direction perpendicular to the film transportation direction in the air ejection nozzle that blows air on the resin film conveyed in one direction The nozzle has a slit shape and has at least one connecting rib for connecting two lips forming the slit at a position other than the side plate. Variable width nozzle characterized by The variable width nozzle according to claim 1, wherein the connecting rib is attached at a tip of a movable nozzle that is an air outlet. The variable width nozzle according to claim 1 or 2, wherein the connecting rib and the two lips are made of a single plate-like member. The variable width nozzle is a variable width nozzle comprising two or more movable nozzles capable of moving on a plenum for supplying air to the variable width nozzle, and a fixed nozzle fixed to the plenum. Item 4. The variable width nozzle according to any one of Items 1 to 3. 5. The variable width nozzle according to claim 1, wherein the connecting rib of the variable width nozzle has a width of the connecting rib of 2 mm or less and a thickness of the connecting rib in the vertical direction of 2 mm or less. . The variable width nozzle according to any one of claims 1 to 5, wherein when there are a plurality of the connecting ribs, a distance between adjacent connecting ribs is 10 mm or more. A tenter oven, wherein the variable width nozzle according to any one of claims 1 to 6 is disposed in at least one zone selected from a preheating zone, a stretching zone, a heat fixing zone, and a cooling zone. In the tenter oven, a plurality of variable width nozzles according to any one of claims 1 to 6 are installed, and the attachment position in the width direction of each connecting rib in the plurality of nozzles is a position coordinate in a direction parallel to the lip. The tenter oven according to claim 7, wherein the tenter oven is mounted so as not to overlap on the same coordinates when projected.

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