JP2005289051A - Air blowoff apparatus, tenter oven and thermoplastic resin film obtained by using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air blowoff apparatus capable of dissolving a curving of a jet flow blown off from a slit and homogeneously heating or cooling the film in the width direction. <P>SOLUTION: The air blowoff apparatus comprises two ducts in which a section area is reduced from an entrance to the interior, having a counter flow type duct arranged so that a main flow direction of an air flown inside may be opposed each other and a first slit for blowing off an air flown from one duct and a second slit for blowing off an air flown from another duct are arranged so as to be adjoined inserting a center division plate. A first run way at the upstream side of the first slit and a second run way at the upstream side of the second slit are formed and a pressure adjusting hole connecting the first run way with the second run way is arranged at a part of the center division plate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a discharge device for spraying a gaseous processing medium onto a film to be processed, and more particularly to an air discharge device suitable for producing a thermoplastic resin film and a tenter oven using the same.

  As a method for producing a thermoplastic resin film, an unstretched resin sheet is stretched in the longitudinal direction, and then the uniaxially stretched film is stretched in the width direction using a tenter oven, or an unstretched resin sheet. A simultaneous biaxial stretching method is known in which a tenter oven is used to simultaneously stretch in the longitudinal direction and the width direction.

  Tenter ovens used in these production methods generally have a plurality of sections with different set temperatures connected in the film transport direction, and the film is heated or cooled to a desired temperature in each section. On the other hand, it is configured to perform preheating, stretching, heat treatment, cooling, and the like. As a method for heating or cooling the film, generally, a method is used in which air is blown toward the surface of the film from an air discharge device arranged to extend in the film width direction. The tenter oven has a plurality of air discharge devices in the longitudinal direction of the film passage, and each air discharge device is fed with air controlled to a desired temperature by a heat exchanger by a fan. The heat exchanger and the fan are configured so that the temperature of the air can be set at least for each section.

  In the case of such an air discharge device, if the temperature, wind speed, and wind direction of the air blown out from the air discharge device are not uniform, heat exchange with the air is not uniform in the film width direction, resulting in uneven film temperature. Film temperature unevenness in the manufacturing process is a cause of film physical property unevenness and thickness unevenness, which not only lowers the quality of the product, but also severely causes tearing of the film in the tenter oven and decreases productivity.

2. Description of the Related Art Conventionally, an air discharge device having a counterflow type duct has been proposed as an air discharge device capable of blowing air at as uniform a wind speed and temperature as possible (see, for example, Patent Documents 1 to 4). The counterflow type duct is a structure in which two ducts whose cross-sectional area decreases from the inlet toward the back are arranged so that the main flow directions of the air flowing through the ducts face each other, and are generated in one duct. The static pressure gradient and the static pressure gradient generated in the other duct form a substantially symmetric distribution in the film width direction. Therefore, the wind speed of the air flowing from each duct to the chamber also forms a distribution that is almost symmetrical in the film width direction. Also, since the air flowing in the duct exchanges heat with the air outside the duct via the duct wall, the temperature gradient generated in the air flowing in one duct and the temperature gradient generated in the air flowing in the other duct are in the film width direction. A substantially symmetric distribution. An air discharge device having a counter-flow type duct is formed by merging air flowing from each duct immediately before or immediately after a slit extending in the film width direction, thereby generating a wind speed distribution and a temperature distribution generated in the film width direction. Are averaged.
U.S. Pat. No. 4170075 (pages 1-6, FIGS. 1-5) Japanese Patent No. 1634915 (page 1-3, FIG. 1-6) Japanese Patent No. 1804334 (page 1-7, FIG. 1-5) European Patent Application Publication No. 0377311 (page 1-4, FIG. 1-2)

  However, in the above air discharge device, the air direction blown from the slit bends in the longitudinal direction of the film, and the air cannot be blown perpendicular to the film surface.

  In the air discharge device described in Patent Document 1, a slit that discharges air flowing from one duct and a slit that discharges air flowing from the other duct are arranged adjacent to each other, and the air discharged from each slit is discharged. , Which is merged immediately after the slit. In this case, since each slit has a wind speed gradient that is substantially symmetrical with respect to the film width direction, the difference in wind speed between the slits increases toward both ends of the air discharge device. Due to the difference in wind speed between the slits, the jet that merges immediately after the slit bends from the fast wind speed side toward the slow wind side.

  The air discharge devices described in Patent Documents 2 to 4 are air discharge devices having counterflow type ducts as in Patent Document 1, but after the air flowing from each duct is merged in the chamber, It is configured to blow out from a single slit. In this case, since the air flowing into the chamber from each duct has a symmetric wind speed gradient in the film width direction, the wind speed difference at the time of merging increases as it goes to both ends of the air discharge device. Due to this wind speed difference, an air flow vortex is formed in the chamber, and the jet is bent in the direction of rotation of the vortex.

  In other words, the air discharge device can blow air almost perpendicular to the film surface near the center, but the bending of the jet expands toward the end and blows air obliquely with respect to the film surface. There is. Therefore, the heat transfer coefficient is smaller near both ends of the film than near the center, and temperature unevenness occurs in the film width direction.

  Further, in a tenter oven configured by connecting sections having different set temperatures in the longitudinal direction of the film, air having different temperatures is mixed from adjacent sections due to the bending of the jet flow. In the air discharge device, the direction in which the jet bends is reversed between one end and the other end, so that large temperature unevenness occurs in the film width direction in the vicinity of the boundary between the sections. In addition, when air having different temperatures is mixed from adjacent sections, there is a problem that the amount of power consumed by the heat exchanger increases and the energy efficiency decreases.

  An object of the present invention is to provide an air discharge device and a tenter oven in which the above-mentioned conventional drawbacks are improved.

The present invention adopts the following configuration in order to achieve the above-mentioned problems. That is,
(1) It is arranged and used so as to extend in the width direction of the film passage, and is composed of a flow path whose cross-sectional area decreases from the duct inlet toward the back, and has an opening on the surface facing the film passage. The first duct is substantially the same structure as the first duct, and is disposed so that the direction from the duct entrance to the back faces the first duct, and is adjacent to the first duct in the longitudinal direction of the film passage. The first duct having a first slit that shares the opening with the first duct and extends in the width direction of the film passage, on the surface facing the film passage, A second chamber that shares an opening with the two ducts and has a second slit extending in the width direction of the film passage on a surface facing the film passage, and between the first chamber and the second chamber Central divider formed In the air discharge device configured so that the edge of the first slit and the second slit is a common long side, each of the first slit and the second slit that are opposite to the edge of the central partition plate By providing a runway formation plate so as to face the central partition plate from the long side, a second runway that leads from the first chamber to the first slit and a second chamber that leads from the second chamber to the second slit. An air discharge device, characterized in that a pressure adjustment hole is formed in a part of the central partition plate to connect the first runway and the second runway.

  (2) The air discharge device according to (1), wherein a plurality of rectifying plates orthogonal to the first slit and the second slit are provided inside the first chamber and the second chamber.

  (3) The length S of the short side of the first slit and / or the length S of the short side of the second slit is 3 to 12 mm, as described in (1) or (2) Air release device.

  (4) The pressure adjusting hole extends continuously or intermittently in the width direction of the film passage, and the length A in the vertical direction of the pressure adjusting hole is 15 to 35 mm. Air release device.

  (5) The length C from the downstream edge of the pressure adjusting hole in the air flow direction to the edge of the central partition plate is 4 to 20 times the S (3) or (4) The air discharge device according to 1.

  (6) When the length in the vertical direction of the first runway and the second runway is Jmm, the short side of the flow path on the first chamber side of the first runway and the second runway The air discharge device according to any one of (3) to (5), wherein a length R with a short side of the flow path on the second chamber side is (3 × S) to (J / 2 + S) mm. .

  (7) A tenter oven comprising a part of the air release device according to any one of (1) to (6).

  Moreover, all the tenter ovens described in (7) are suitable for use in the production of thermoplastic resin films, and can be used for both the sequential biaxial stretching method and the simultaneous biaxial stretching method.

  Since the air discharge device of the present invention can blow air substantially perpendicularly to the opposing film surface, the film can be heated or cooled uniformly in the width direction. Moreover, if the tenter oven provided with the air release device of the present invention is used, the physical property unevenness and thickness unevenness of the film are improved, and the quality of the product is improved. Moreover, the tear which arises by the temperature nonuniformity in a tenter oven reduces, and productivity improves. Moreover, since the air mixing amount from adjacent sections with different set temperatures is reduced, the power consumption of the heat exchanger is reduced, and there is an energy saving effect.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 is a schematic configuration diagram of a tenter oven using an air discharge device 1 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the air release device 1 according to the embodiment of the present invention, and is a view taken along arrows II in FIG. 3 is a view taken in the direction of arrows II-II in FIG. FIG. 9 is a cross-sectional view of the air release device 1 according to one embodiment of the present invention. FIG. 12 is a perspective view of the air release device 1 according to one embodiment of the present invention. 13 is a cross-sectional view of the air release device of FIG.

  As shown in FIG. 1, the tenter oven has a plurality of air discharge devices 1 in the longitudinal direction of the film passage 30. The air discharge device 1 is arranged and used so as to extend in the width direction of the film passage 30. Moreover, although the air discharge device 1 is disposed and used on the upper side and the lower side of the film passage 30, only the air discharge device disposed on the lower side is shown in the drawing. Air controlled to a desired temperature by a heat exchanger (not shown) is sent from the duct inlets 22 and 23 to the air discharge device 1 by a fan (not shown) and discharged from the slits 8 and 9. The film 31 to be processed is gripped at both ends by a clip (not shown) and is conveyed in the longitudinal direction 32 of the film passage 30.

  The air discharge device 1 of the present invention is roughly divided into six spaces, and each space is divided into a first duct 2, a second duct 3, a first chamber 6, a second chamber 7, and a first runway 16. This is called the second runway 17. In the first duct 2, air flows in the direction of the arrow 52 from the inlet 22 toward the back. The first duct 2 is configured by a flow path having a rectangular cross-section in a direction orthogonal to the air flow 52, and has an opening 4 connected to the first chamber 6 on the surface facing the film passage 30. The first duct 2 has a rectangular flow path in the direction orthogonal to the air flow 52, but the first duct 2 is required to be perpendicular at all vertices of the rectangle forming the cross section. However, it is not always necessary to make the apex right angle unless it deviates from the object of the present invention that air can be blown substantially perpendicularly to the opposing film surface, and the apex should be appropriately rounded There is no problem even if it is processed. The opening 4 may be a continuous slit, but in order not to reduce the rigidity of the duct, a structure in which a plurality of long holes are arranged as shown in the drawing is preferable. Since the air flow 52 in the first duct 2 is distributed to the flow 54 passing through the opening 4, the flow rate gradually decreases from the duct inlet 22 toward the back (the duct end facing the duct inlet 22). . Therefore, the first duct 2 is preferably configured such that the cross-sectional area of the air flow 52 decreases from the inlet 22 toward the back. The second duct 3 has substantially the same structure as the first duct 2 and is disposed so that the air flow 53 in the second duct 3 faces the air flow 52 in the first duct 2. The second duct 3 has an opening 5 connected to the second chamber 7, and the air flow 53 in the second duct 3 is distributed to a flow 55 passing through the opening 5.

  As shown in FIG. 2, the first chamber 6 and the first runway 16 are separated by the runway forming plate 12. Similarly, the second chamber 7 and the second runway 17 are separated by the runway forming plate 13. The exit of the first runway 16 is the first slit 8, the exit of the second runway 17 is the second slit 9, and the first slit 8 and the second slit 9 have a common edge of the central partition plate 11. The long side is configured. The first runway 16 and the second runway 17 define the vertical length as J, the short side length of the entrance surface as R, and the short side length of the exit surface (slit) as S. . The central partition plate 11 has a pressure adjustment hole 14 that connects the first runway 16 and the second runway 17. The pressure adjusting hole 14 may be a continuous slit, or may have a structure in which a plurality of long holes are arranged as shown in FIG. Further, for the purpose of smoothing the air flow in the air discharge device 1, the cross sections of the first chamber 6 and the second chamber 7 may be formed as shown in FIG.

  As shown in FIG. 2, when the length of the pressure adjusting hole 14 in the vertical direction is A and the length from the downstream edge of the pressure adjusting hole 14 in the air flow direction to the edge of the central partition plate 11 is C, As described above, since the pressure adjusting hole 14 is provided at a position connecting the first and second runways 16 and 17, the relationship of J ≧ A + C is inevitably established. By being configured as described above, the air flow 56 in the first chamber 6 and the air flow 57 in the second chamber 7 change the flow directions in a direction substantially parallel to the central partition plate 11. An air flow 51 is generated in the pressure adjusting hole 14 due to the static pressure difference between the first and second runways 16 and 17, and the air flow 58 discharged from the first slit and the air discharged from the second slit. The flow velocity of the stream 59 is almost equal. As a result, air can be blown perpendicularly to the opposing film surface.

  Further, it is preferable to provide a plurality of rectifying plates 18 orthogonal to the slits 8 and 9 inside the first chamber 6 and the second chamber 7 as shown in FIGS. The rectifying plate 18 may also be installed in a conventional air discharge device, and has an effect of reducing the flow of the air discharged from the slits 8 and 9 in the width direction of the film passage 30.

  When the air release device 1 is used for the production of a thermoplastic resin film, the air wind speed on the slit surface varies depending on the conveyance speed and composition of the film 31, the distance from the slit surface to the film surface, the required characteristics of the product, etc. Generally, it is the range of 5-35 m / sec. When used in such a wind speed range, the length S of the short side of the slit is preferably 3 to 12 mm. The length of the slit extending in the width direction of the film 31 is determined by the width of the film 31 to be processed, but is generally 1 to 12 m.

  The length A of the pressure adjusting hole 14 in the vertical direction is preferably 15 to 35 mm. If A is too small, the air flow 51 is insufficient, and a sufficient pressure adjusting effect cannot be obtained. If A is too large, the air flow 51 becomes excessive, and the flow velocity of the air flow 58 discharged from the first slit and the flow velocity of the air flow 59 discharged from the second slit are reversed.

  If the length C from the downstream edge of the pressure adjustment hole in the air flow direction to the edge of the central partition plate is too small, the turbulence generated in the flow in the runway by the air flow 51 cannot be sufficiently rectified. It is preferably at least 4 times S. Increasing C improves the rectifying effect, but increases the pressure loss and requires a fan with a high static pressure. Moreover, the dimension of the air discharge device 1 in the vertical direction is also increased. Therefore, practically, C is preferably 20 times or less of S.

  The length R of the short side of the entrance surface of the first runway and the second runway is preferably (3 × S) to (J / 2 + S). If R is too small, the pressure loss increases, and a fan with a high static pressure is required, which is not preferable. If R is too large, the air flow 56 in the first chamber 6 and the air flow 57 in the second chamber 7 cannot change the direction of the flow in a direction substantially parallel to the central partition plate 11, Since the air flow in the first runway and the air flow in the second runway collide with each other via the pressure adjustment hole 14, it is not preferable.

  Hereinafter, the present invention will be described more specifically with reference to examples.

[Example 1]
An air discharge device 1 having a cross section as shown in FIGS. 2 and 3 was produced. The first slit 8 and the second slit 9 were rectangular with a long side length of 6 m and a short side length S of 5 mm. The first runway 16 and the second runway 17 have a vertical length J of 65 mm and a short side length R of the entrance surface of 30 mm. The length A of the pressure adjustment hole 14 in the vertical direction was 20 mm, and the length C from the downstream edge of the pressure adjustment hole 14 in the air flow direction to the edge of the central partition plate was 40 mm. The pressure adjusting hole 14 has a structure in which a plurality of long holes are arranged in the width direction of the film passage 30, the long side length of the long holes is 120 mm, and the arrangement pitch of the long holes is 125 mm. The openings 4 and 5 have a structure in which a plurality of long holes are arranged in the width direction of the film passage 30, the long sides of the long holes are 120 mm long, the arrangement pitch of the long holes is 125 mm, and the short sides of the long holes are The length was 11 mm. The inlet 22 of the first duct and the inlet 23 of the second duct were rectangular with a length of 270 mm in the vertical direction and a length of 220 mm in the longitudinal direction of the film passage 30.

  4 is a view taken in the direction of arrows III-III in FIG. The wind speed measurement positions of the air flow 58 discharged from the first slit and the air flow 59 discharged from the second slit will be described with reference to FIG. Measurement points in the plane of the first slit 8 were determined as P11, P12, P13, P14, and P15 sequentially from the first duct inlet 22 to the second duct inlet 23. When the length of the long side of the slit is L, P11 is a position away from the slit end on the first duct inlet 22 side by L / 10 in the direction of the second duct inlet 23, and P15 is from the slit end on the second duct inlet 23 side. Positions L / 10 apart in the direction of the first duct inlet 22, P12 to P14 are positions where P11 and P15 are divided at substantially equal intervals. The measurement points in the surface of the second slit 9 were determined as P21, P22, P23, P24, and P25 sequentially from the first duct inlet 22 to the second duct inlet 23. The positions of P21 to P25 were determined by the same method as P11 to P15.

  The wind speed was measured using a Prandtl type Pitot tube with the total pressure measurement hole of the Pitot tube fixed at the measurement position. Since the wind speed value fluctuated over time, the sampling interval was set to 1 second, and the maximum value when measured continuously for 15 seconds was recorded. The fan (not shown) was operated so that the average of the five measured values of P11 to P15 and the average of the five measured values of P21 to P25 were 10 ± 1 m / sec. Moreover, the heat exchanger (not shown) was not used but air at room temperature was blown.

  FIG. 5 is a perspective view of the air release device 1 according to one embodiment of the present invention. A method for measuring the bending amount X of the jet flow after the air flow 58 discharged from the first slit and the air flow 59 discharged from the second slit merge will be described with reference to FIG. Origins O1 to O5 were determined in the same manner as P11 to P15 on the intersection line between the surface 80 mm away from the slit surface in the direction of the film passage 30 and the surface obtained by extending the central partition plate 11. The respective coordinate axes were taken from the respective origins in the longitudinal direction of the film passage 30, and the coordinate axes were defined with the first slit 8 side as positive. At each coordinate with O1 to O5 as the origin, the wind speed of the jet was measured in 1 mm increments along the respective coordinate axes, and the coordinate value at which the wind speed was maximum was recorded as the bending amount X of the jet.

  The measurement results of Example 1 are shown in Table 1. The bending amount X of the jet flow at each coordinate with O1 to O5 as the origin is within ± 1 mm, and the air discharge device 1 capable of blowing air substantially perpendicular to the film surface was obtained.

[Example 2]
As shown in FIGS. 12 and 13, rectifying plates 18 are installed at a pitch of 150 mm inside the first chamber 6 and the second chamber 7. Other conditions were the same as in Example 1. The measurement results are shown in Table 1. An air discharge device 1 was obtained in which the amount of bending X of the jet flow was the same as in Example 1, and the uniformity of the wind speed was better than in Example 1.

[Comparative Example 1]
FIG. 6 is a general form of a conventionally used air discharge device 1, and is a view taken along arrows IV-IV in FIG. FIG. 7 is a VV arrow view of FIG. The main difference from Example 1 is that the length J in the vertical direction of the first runway 16 and the second runway 17 is as short as 10 mm, and the pressure adjusting hole 14 is not provided in the central partition plate 11. That is.

  The measurement results of Comparative Example 1 are shown in Table 1. The bending amount X of the jet is large at O1 and O5 near the end of the slit. Further, O1 and O5 are bent in opposite directions. The cause of the bending of the jet is the difference in wind speed between the slits. In the case of the air discharge device 1 having a counterflow type duct, a wind speed difference is generated between the air flow 54 and the air flow 55. Therefore, a wind speed difference also occurs between the air flow 58 and the air flow 59. The difference in wind speed between P11 and P21 is 4.6 m / sec, and the difference in wind speed between P15 and P25 is 2.2 m / sec, which correlates with the bending amount X of the jet. The jet is bent from the fast wind side to the slow side. Use of such an air discharge device is not preferable because it causes tearing and uneven physical properties due to insufficient heating or cooling near the edge of the film.

[Comparative Example 2]
FIG. 8 shows a general form different from the comparative example 1 of the air discharge device 1 conventionally used. The main difference from the first embodiment is that the central partition plate 11 is not provided. Therefore, the air flow 54 from the first duct 2 and the air flow 55 from the second duct 3 merge in the first chamber 6 and are discharged from the first slit 8. The length S of the short side of the first slit 8 was set to 10 mm in order to make the flow rate of the released air equal to those in Examples 1 and 2 and Comparative Example 1. The length J in the vertical direction of the first runway 16 was 20 mm.

  The measurement results of Comparative Example 2 are shown in Table 1. In the case of the air discharge device 1 having a counterflow type duct, a wind speed difference is generated between the air flow 54 and the air flow 55. A jet of air discharged from the first slit 8 is bent due to a vortex generated when an air flow having a difference in wind speed collides in the first chamber. Use of such an air discharge device is not preferable because it causes tearing and uneven physical properties due to insufficient heating or cooling near the edge of the film.

[Example 3]
In the air release device 1 of Example 1, the vertical length A of the pressure adjusting hole 14 was changed in the range of 10-40. The vertical length J of the first runway 16 and the second runway 17 is fixed at 65 mm, and the length C from the downstream edge of the pressure adjusting hole 14 in the air flow direction to the edge of the central partition plate is ( 60-A) mm. At this time, the bending amount X of the jet at the coordinates with O1 as the origin was measured.

  The measurement results are shown in FIG. When A was 10 mm, pressure adjustment by the air flow 51 was insufficient, and X was +3 mm. When A was 40 mm, the air flow 51 became too large and X became -3 mm. When A was in the range of 15 to 35 mm, X was good within ± 1 mm.

[Example 4]
In the air release device 1 of Example 1, the length C from the downstream edge of the pressure adjusting hole 14 in the air flow direction to the edge of the central partition plate was changed within a range of 10 to 40 mm. The length A in the vertical direction of the pressure adjusting hole 14 was fixed to 20 mm, and the length J in the vertical direction of the first runway 16 and the second runway 17 was fixed to 65 mm. At this time, the bending amount X of the jet at the coordinates with O1 as the origin was measured.

  The measurement results are shown in FIG. When C was 10 mm, the section for rectifying the air flow 51 was too short, and X was +7 mm. When C was 15 mm, X was +4 mm for the same reason. When C was in the range of 20 to 40 mm, X was as good as ± 1 mm. The rectifying effect of the air flowing between the flat plates such as the first runway 16 and the second runway 17 is inversely proportional to the gap between the flat plates and proportional to the length of the flat plate. That is, if the length S of the short side of the slit is doubled, C is also required to be doubled. Therefore, the above preferable range of C can be expressed by a ratio with S. Further, since the rectification effect is improved as C is increased, the good range of C with respect to X is four times or more of S.

  However, in order to maintain the relationship of J ≧ A + C, if C is increased, J must be increased. Therefore, the pressure loss of the 1st runway 16 and the 2nd runway 17 becomes large. Moreover, the dimension of the air discharge device 1 in the vertical direction is also increased. Therefore, practically, C is preferably 20 times or less of S.

[Example 5]
In the air release device 1 of the first embodiment, when R is changed to the same length as S and the runway formation plates 12 and 13 are arranged so as to be parallel to the central partition plate 11, the first runway 16 and The rectifying effect of the second runway 17 is improved, but the pressure loss is increased. The pressure loss when the flow rate is constant is theoretically inversely proportional to the cube of the gap between the parallel plates. If the central partition plate 11 is removed, the pressure loss will be 1/8 or less, and the pressure loss level will be reduced to a harmless level, but the effect of the present invention cannot be obtained. The range in which the pressure loss is smaller than when the central partition plate 11 is provided and the central partition plate 11 is not provided is (S + R) / 2 ≧ 2S. That is, R is preferably (3 × S) or more.

  Further, when R is increased in the air discharge device 1 of the first embodiment, that is, when the taper angle θ between the runway forming plate 12 or 13 and the central partition plate 11 is increased, the jet flow at the coordinates with O1 as the origin is set. The bending amount X was measured. X when tan θ = (R−S) / J = 1/2 remained at +1 mm, but X when tan θ = 2/3 was increased to +4 mm. Therefore, when (R−S) / J ≦ 1/2, X is within ± 1 mm, and therefore R is preferably (J / 2 + S) or less.

  The air discharge device of the present invention can be applied not only to a tenter oven but also to a drying device, an air knife, and the like, but its application range is not limited thereto.

It is a schematic block diagram of the tenter oven using the air discharge device which concerns on one Embodiment of this invention. It is sectional drawing of the air discharge device which concerns on one Embodiment of this invention, and is II arrow directional view of FIG. It is the II-II arrow line view of FIG. It is the III-III arrow line view of FIG. It is a perspective view of the air discharge device concerning one embodiment of the present invention. It is a general form of the air discharge apparatus used conventionally, and is a IV-IV arrow line view of FIG. It is a VV arrow line view of FIG. This is a general form of a conventionally used air discharge device. It is sectional drawing of the air discharge apparatus which concerns on one Embodiment of this invention. It is a graph which shows the relationship between the length of the vertical direction of a pressure adjustment hole, and the bending amount of a jet. It is a graph which shows the relationship between the length from the downstream edge of a pressure adjustment hole to the edge of a center partition plate, and the bending amount of a jet. It is a perspective view of the air discharge device concerning one embodiment of the present invention. It is sectional drawing of the air discharge | release apparatus of FIG.

Explanation of symbols

1: air discharge device 2: first duct 3: second duct 4: opening of first duct 5: opening of second duct 6: first chamber 7: second chamber 8: first slit 9: second Slit 11: Central partition plate 12: Runway formation plate of the first runway 13: Runway formation plate of the second runway 14: Pressure adjustment hole 16: First runway 17: Second runway 18: Rectification plate 22 : First duct inlet 23: Second duct inlet 30: Film passage 31: Film 32: Film transport direction 51: Air flow 52 generated in the pressure adjustment hole due to the static pressure difference between the first and second runways 52: Air flow 53 in the first duct 53: Air flow in the second duct 54: Air flow from the first duct to the first chamber 55: Air flow from the second duct to the second chamber 56: Air in the first chamber Flow 57: Air flow 58 in the second chamber Flow of air released from the first slit 59: Flow of air released from the second slit A: Vertical length of the pressure adjustment hole C: From the downstream edge of the pressure adjustment hole to the edge of the central partition plate Length J: length in the vertical direction of the first runway and the second runway L: length of the long side of the slit R: length of the short side of the entrance surface of the first runway and the second runway S : Length of short side of slit X: Bending amount of jet O1-O5: Origin of wind speed measurement position P11-P15: Wind speed measurement point in first slit surface P21-P25: Wind speed measurement point in second slit surface

Claims (8)

  A first duct that is arranged to be used so as to extend in the width direction of the film passage, is configured by a flow path having a cross-sectional area that decreases from the duct inlet toward the back, and has an opening on a surface facing the film passage. And the first duct is substantially the same structure, and is disposed so that the direction from the duct inlet toward the back is opposed to the first duct, and is disposed adjacent to the first duct in the longitudinal direction of the film passage. The second duct, the first chamber sharing the opening with the first duct and having a first slit extending in the width direction of the film passage on the surface facing the film passage, and the second duct A second chamber having a second slit sharing the opening and extending in the width direction of the film passage on a surface facing the film passage, and formed between the first chamber and the second chamber D of center divider In the air discharge device configured such that the first slit and the second slit have a common long side, the length of each of the first slit and the second slit that are opposite to the edge of the central partition plate By providing a runway formation plate so as to face the central partition plate from the side, a second runway connected to the first slit from the first chamber and the second slit from the second chamber to the second slit. An air discharge device, characterized in that a pressure adjusting hole is formed in a part of the central partition plate to connect the first runway and the second runway.   2. The air discharge device according to claim 1, wherein a plurality of rectifying plates orthogonal to the first slit and the second slit are provided inside the first chamber and the second chamber.   3. The air discharge device according to claim 1, wherein a length S of a short side of the first slit and / or a length S of a short side of the second slit is 3 to 12 mm.   The air discharge device according to claim 3, wherein the pressure adjusting hole extends continuously or intermittently in the width direction of the film passage, and the length A in the vertical direction of the pressure adjusting hole is 15 to 35 mm. .   The air discharge according to claim 3 or 4, wherein a length C from the downstream edge of the pressure adjusting hole to the edge of the central partition plate is 4 to 20 times the S. apparatus.   When the length in the vertical direction of the first runway and the second runway is Jmm, the short side of the flow path on the first chamber side of the first runway and the second side of the second runway 6. The air discharge device according to claim 3, wherein a length R of the short side of the flow path on the chamber side is (3 × S) to (J / 2 + S) mm.   A tenter oven comprising a part of the air release device according to claim 1.   A thermoplastic resin film obtained by preheating, stretching, heat treatment, and cooling by the tenter oven according to claim 7.

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