JP2022069741A - Air injection structure and tenter oven with air injection structure - Google Patents

Abstract

To provide an air injection structure that can provide more uniform heat to the film.SOLUTION: An air injection structure for blowing air onto a film being conveyed in a predetermined direction D1 along a conveying channel, comprising an injection nozzle 6 with a nozzle wall 61 provided with a number of injection holes, and a plurality of guide plates 7 arranged along the film width direction D2. Each guide plate 7 is provided inside or outside the nozzle wall 61 and can be swiveled around a swivel axis extending in a predetermined direction D1.SELECTED DRAWING: Figure 2

Description

The present invention relates to an air injection structure and a tenter oven provided with the air injection structure.

As an apparatus for producing a resin film, there is known an apparatus for transporting and heat-treating a resin film in a tenter oven while grasping both edges of the film with clips and stretching the film. The tenter oven includes a pair of upper and lower air injection members arranged so as to sandwich the film, and is configured to inject heated air toward the film from injection holes provided in each air injection member.

In such a tenter oven, various devices for uniformly heating the film in the width direction have been proposed. For example, the tenter oven disclosed in Patent Document 1 is configured to eliminate the bending of the jet and blow air substantially perpendicular to the film surface.

Japanese Unexamined Patent Publication No. 2005-289851

However, it may not be possible to prevent uneven heating simply by making the air ejection direction perpendicular to the film surface. For example, if the wind flow is disturbed by the clips that grip both edges of the film, the amount of heat decreases on both sides in the width direction of the film, and uneven heating occurs.

An object of the present invention is to provide an air injection structure capable of imparting a more uniform amount of heat to a film and a tenter oven provided with the air injection structure.

The air injection structure according to the present invention is an air injection structure for blowing air onto a film conveyed in a predetermined direction through a transfer path, and has an injection nozzle having a nozzle wall provided with a large number of injection holes and the film. A plurality of guide plates arranged along the width direction of the nozzle are provided, and each of the plurality of guide plates is provided inside or outside the nozzle wall and is centered on a swivel axis extending in the predetermined direction. It is possible to turn.

Further, another air injection structure according to the present invention is an air injection structure for blowing air onto a film conveyed in a predetermined direction through a transfer path, and is an injection nozzle having a nozzle wall provided with a large number of injection holes. A plurality of guide plates arranged along the width direction of the film, and at least a part of the guide plates among the plurality of guide plates are inclined with respect to the thickness direction of the film. However, the plurality of guide plates are provided inside or outside the nozzle wall.

Further, the tenter oven according to the present invention has the above-mentioned air transport structure.

According to the air injection structure and the tenter oven according to the present invention, each of the plurality of guide plates can be swiveled around a swivel axis extending in a predetermined direction, and therefore, depending on the film characteristics, the structure of the tenter oven, and the like. The direction of air injection can be adjusted, which allows the film to be heated more uniformly.

Further, according to the other air injection structure and the tenter oven according to the present invention, at least a part of the guide plates is inclined with respect to the thickness direction of the film, so that the air is guided toward the inclined direction and the whole is guided. The film can be heated more uniformly over the entire width direction.

The schematic vertical sectional view which shows the whole structure of the tenter oven which concerns on 1st Embodiment of this invention. A perspective perspective view showing a lower duct provided in the tenter oven shown in FIG. 1. (A) is a sectional view taken along line IIIa-IIIa of FIG. 2, (b) is a plan view showing an injection nozzle provided in the duct shown in (a), and (c) is a sectional view taken along line IIIc-IIIc of (a). The cross-sectional view which shows the lower duct provided in the tenter oven which concerns on 2nd Embodiment of this invention. (A) is a perspective perspective view showing a duct according to a modified example of the embodiment of the present invention, and (b) is a sectional view taken along line Vb-Vb of (a).

[First Embodiment]
Hereinafter, the tenter oven according to the first embodiment of the present invention will be described with reference to the accompanying drawings. With reference to FIG. 1, the tenter oven 1 of the present embodiment is used in stretch molding of a film (thermoplastic resin film / not shown), and is formed into a film in the housing 2 and the housing 2. An air injection means 3 for blowing air is provided, and a film carry-in inlet 21a and a film carry-out port 22a are provided on the front wall 21 and the rear wall 22 of the housing 2, respectively. Both edges of the film are gripped by clips (not shown), and the transport path R in the housing 2 is transferred in the predetermined direction D1.

The air injection means 3 includes a pair of upper and lower ducts 4 and a fan (not shown) for sending air (heated air) to the pair of upper and lower ducts 4. The pair of upper and lower ducts 4 are arranged so as to face each other with a gap in the vertical direction D3, and the gap serves as a film transport path R. Since the pair of upper and lower ducts 4 have substantially the same configuration, only the lower duct 4 will be described here.

With reference to FIGS. 2 and 3, the duct 4 includes a tubular header box 5 extending along the width direction D2 of the film and a plurality of ducts 4 arranged in parallel in the predetermined direction D1 (two in the example shown in FIG. 1). ), And the injection nozzle 6. The header box 5 has a wall surface 51 facing the transfer path R and a pair of side walls 52 and 53 facing each other in the width direction D2. Each injection nozzle 6 extends along the width direction D2, extends from the wall surface 51 of the header box 5 toward the transfer path R (upward in the case of the lower duct 4), and communicates with the header box 5. .. The tip wall 61 of the injection nozzle 6 faces the transport path R, and is a nozzle wall 61 provided with a large number of injection holes 62 (FIG. 3B), and these large number of injection holes 62 extend in the width direction D2. A plurality of rows of injection holes are arranged in a plane so as to be lined up in a predetermined direction D1. An air supply port 52a is provided on one side wall 52 of the header box 5, and air sent out by a fan (not shown) is supplied into the header box 5 via the air supply port 52a.

The air injection means 3 further includes a plurality of guide plates 7 arranged along the width direction D2 inside each nozzle wall 61 (inside the injection nozzle 6). Each guide plate 7 has a first end surface 7a and a second end surface 7b extending along a predetermined direction D1. The first end surface 7a (here, the upper end surface) is located closer to the transport path R than the second end surface 7b (here, the lower end surface). Further, each guide plate 7 is individually swivelable around a swivel shaft P extending in a predetermined direction D1. Here, the air injection structure is configured by the injection nozzle 6 and the plurality of guide plates 7.

In such a configuration, the air supplied into the header box 5 through the air supply port 52a flows into the injection nozzle 6 and is injected from each injection hole 62 toward the film. At this time, since air flows along the plurality of guide plates 7 (the wide surface of the guide plates 7 extending in the direction intersecting the nozzle wall 61) in the injection nozzle 6, the vertical direction (film thickness direction) D3. By adjusting the inclination angle of the guide plate 7 with respect to the water, the injection direction of the air injected from the injection nozzle 6 can be adjusted.

For example, in the example shown in FIG. 3, each guide plate 7 is inclined with respect to the vertical direction D3 so that the second end surface 7b is closer to the center of the width direction D2 than the first end surface 7a (that is,). It is set so as to incline outward in the width direction D2 as it approaches the transport path R). As a result, the air is guided outward in the width direction D2 by the guide plate 7, and even if the wind flow is disturbed on both sides of the width direction D2 by a clip or the like that grips the film, the film is more uniform over the entire width direction D2 as a whole. Can be heated to.

The guide plate 7 may be swiveled around the swivel shaft P manually, or may be swiveled by a driving means such as a motor.
[Second Embodiment]
Next, the tenter oven according to the second embodiment of the present invention will be described. In the following description, substantially the same members as those of the first embodiment are designated by the same reference numbers, and the description thereof will be omitted.

With reference to FIG. 4, the tenter oven according to the present embodiment includes a plurality of guide plates 71 instead of the plurality of guide plates 7. These plurality of guide plates 71 are substantially the same as the guide plates 7, but unlike the guide plates 7, they are not swivelable and are fixed to the injection nozzle 6. Of these plurality of guide plates 71, at least a part of the guide plates 71 is inclined with respect to the vertical direction D3, and the number of the guide plates 71 inclined in this way, the inclination direction and the inclination angle are the characteristics of the tenter oven and the like. It is set appropriately according to.

For example, in the example shown in FIG. 4, all the guide plates 71 are arranged so that the distance between the first end faces 71a gradually increases from the center of the width direction D2 toward the outside, and the inclination direction thereof is symmetrical in the width direction D2. It is set to be. That is, the guide plates 71 located at both ends of the width direction D2 are arranged to be inclined with respect to the vertical direction D3, the inclination angle gradually decreases toward the center of the width direction D2, and the second end surface 71b becomes the first end surface 71a. It is set to be closer to the center of D2 in the width direction.

By installing the guide plate 71 that is inclined with respect to the vertical direction D3 in this way according to the characteristics of the tenter oven, air can be guided in a desired direction, and uneven heating of the film can be suppressed. Can be done.

The tilting direction of the guide plate 71 is not limited to the example shown in FIG. 4, and the tilt angle of the guide plate 71 may be the same as shown in FIG. 3 of the first embodiment, instead of this. The inclination directions of all the guide plates 71 may be the same. Further, the guide plate 71 extending along the vertical direction D3 may be included in a part thereof.

Although the tenter oven according to the embodiment of the present invention has been described above with reference to the accompanying drawings, the present invention is not limited to such an embodiment, and various modifications and modifications can be made without departing from the scope of the present invention. Is.

For example, in each of the above embodiments, the plurality of guide plates 7 (71) are provided inside the nozzle wall 61, but as shown in FIG. 5, they may be provided outside the nozzle wall 61. Can also obtain the same effect as described above. In this case, it is preferable to provide a peripheral wall 8 surrounding a plurality of guide plates 7 (71).

Further, the number of the injection nozzles 6 extending from the wall surface 51 of the header box 5 does not have to be a plurality, and may be one.

1 Tenter oven 4 Duct 5 Header box 6 Injection nozzle 61 Nozzle wall 62 Injection hole 7,71 Guide plates 7a, 71a First end face 7b, 71b Second end face P Swing shaft R Transport path

Claims (4)

It is an air injection structure for blowing air onto a film that is conveyed in a predetermined direction through a transfer path.
An injection nozzle having a nozzle wall provided with a large number of injection holes,
A plurality of guide plates arranged along the width direction of the film are provided.
An air injection structure in which each of the plurality of guide plates is provided inside or outside the nozzle wall and can swivel around a swivel shaft extending in a predetermined direction. It is an air injection structure for blowing air onto a film that is conveyed in a predetermined direction through a transfer path.
An injection nozzle having a nozzle wall provided with a large number of injection holes,
A plurality of guide plates arranged along the width direction of the film are provided.
Of the plurality of guide plates, at least a part of the guide plates is inclined with respect to the thickness direction of the film.
The plurality of guide plates have an air injection structure provided inside or outside the nozzle wall. The air injection structure according to claim 2, wherein each of the plurality of guide plates can be swiveled around a swivel shaft extending in the predetermined direction. A tenter oven having the air injection structure according to any one of claims 1 to 3.

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