JPH01314140A - Hot air supply device for horizontal stretching machine for film production - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Industrial Application Field The present invention relates to a hot air supply device for a transverse stretching machine for film production.

(b) Conventional technology A transverse stretching machine for film production is a device that feeds a resin film through an open space where hot air is supplied, and stretches it in the transverse direction by gripping both edges with clips. . Both edges of the unstretched resin film are held by clips, and the distance between the two clips is gradually increased during passage through the open space. During this time, the hot air supply device blows hot air from both the upper and lower surfaces of the resin film to maintain the resin film at a high temperature. As a conventional hot air supply device for this purpose, there is one shown in FIGS. 8 and 9. The air duct 50 is constituted by a cylindrical body with a rectangular cross section. A slit 52 for blowing out hot air is formed on the upper surface of the air duct 50 in FIG. The inside of the air duct 50 is separated by a punching plate 54 into an upper chamber 57 and a lower chamber 58 in FIGS. 8 and 9. The punching plate 54 is provided with a large number of holes. A corrugated plate 56 is provided on the punching plate 54.

This air duct 50 is arranged so that the hot air blowing slit 52 is parallel to the width direction of the resin film. The hot air is supplied to the lower chamber 58, passes through the punching plate 54 and the corrugated plate 56, and is blown onto the resin film from the hot air blowing slit 52. Air duct 50 like this
are arranged in large numbers on the upper and lower surfaces of the resin film.

(c) Problems to be Solved by the Invention However, the above-mentioned conventional hot air supply device for a horizontal stretching machine for film production has a problem in that the speed of the hot air supplied from the hot air blowing slit is not uniform. . That is, generally as shown in FIG.
The end side opposite to the hot air supply side tends to blow out hot air at high speed. If the speed of the hot air (that is, the amount of air) blown out from the hot air blowing slit 52 is not uniform as described above, the temperature of the resin film will be uneven, and the high-temperature portion will be stretched more strongly, which will reduce the thickness of the resin film. becomes non-uniform. The present invention aims to solve these problems.

(d) Means for Solving the Problems The present invention provides another internal duct within the air duct, and the hot air supplied into the air duct from the hot air supply slit of the internal duct is passed through the hot air blowing slit of the air duct. The above problem is solved by ejecting. That is, the hot air supply device of the transverse stretching machine for film production according to the present invention heats the resin film (12) that is continuously fed through the oven (10) with hot air, and clips both ends of the resin film in the width direction, respectively. A hot air supply device (16) of a transverse stretching machine for film production that stretches a resin film in the transverse direction by gripping the resin film with the clips (14) and enlarging the dimensions between the clips. a closed cylindrical air duct (24);
a hot air blowing slit (30) provided along the width direction of the resin film in the resin film facing portion of the air duct;
The second chamber (32) on the side of the air duct with the hot air blowing slit
and a first chamber (34) on the opposite side, a punching plate (36) with a large number of small holes, a corrugated plate (38) provided between the punching plate and a slit for blowing out hot air, and a first chamber (34) on the opposite side. It is intended for devices that have a heater (22) and a fan (20) that can be supplied, and a cylinder having a cross-sectional shape smaller than the first chamber of the air duct and a length equal to the total length of the air duct is installed in the first chamber of the air duct. A shaped internal duct (40) is provided, and a hot air supply slit (42) is provided in the longitudinal direction on the opposite side of the internal duct from the side facing the punching plate, and hot air is supplied by a heater and a fan. The gap between one end of the internal duct and one end of the air duct shall be closed, and the other end of the internal duct shall be closed so that hot air is supplied from one end of the internal duct to the inside of the internal duct. It is characterized by Note that the numbers in parentheses indicate corresponding members in the embodiments described later.

In addition, two slits for hot air supply are provided in the internal duct.
It is also possible to supply hot air from directions opposite to each other. Moreover, the width dimension of the hot air supply slit of the internal duct can also be made adjustable. Moreover, the width dimension of the hot air supply slit can also be changed in the longitudinal direction.

(e) Hot air is supplied to the internal duct by the working heater and fan. The hot air is supplied from the internal duct through the hot air supply slit toward the side of the first chamber opposite to the side where the punching plate is disposed. The hot air supplied to the first chamber passes through the punching plate, bypasses the corrugated plate, and is blown onto the resin film from the hot air blowing slit in the air duct. At the stage when air blows out from the hot air supply slit in the internal duct to the first chamber, there is variation in the wind speed depending on the longitudinal position of the hot air supply slit. It becomes uniform and equalized during the movement stage. Therefore, at the stage of blowing out from the hot air blowing slit of the air duct, the hot air blows out at a substantially uniform wind speed in the longitudinal direction of the hot air blowing slit. As a result, the resin film is uniformly heated in the width direction and stretched in a negative direction, thereby reducing variations in thickness.

When two hot air supply slits are provided in the internal duct and hot air is supplied from opposite directions, variations in the speed of the hot air supplied from the two hot air supply slits cancel each other out, making the hot air more efficient. Can be supplied evenly.

(f) Example Figure 3 shows the entire transverse stretching machine for film production.

The resin film 12 is supplied from the left side of the oven 10 in FIG. 3, and the stretched resin film 12' is fed into the oven 10.
exit from the right side. Both edges of the resin film 12 are held by clips 14 disposed on both edges thereof. With the clip 14 gripping the resin film 12,
It runs at the same speed as the resin film 12. 2
The distance between the two clips 14 gradually increases within the oven 10. Thereby, the resin film 12 is stretched to the resin film 12'. Inside the oven 10, the resin film 12 is heated by hot air.

Hot air is supplied by a hot air supply device 16. A large number of hot air supply devices 16 are arranged at predetermined intervals in the traveling direction of the resin film 12. Further, the hot air supply device 16 is arranged on both the upper surface side and the lower surface side of the resin film 12. As shown in FIG. 4, the hot air supply device 16 includes a fan 20 provided in the plenum chamber 18, a heater 22 (see FIG. 3) that heats the air sucked into the plenum chamber 18, and an air duct 24. ing. Note that a total of eight air ducts 24 are provided, four on the upper and lower sides, corresponding to one plenum chamber 18. Fan 20 is driven by a motor 26. A filter 28 is provided between the plenum chamber 18 and the air duct 24. The air duct 24 has a structure as shown in FIGS. 1 and 2. That is, the air duct 24 is a cylindrical body with a rectangular cross section, and the upper surface in FIG. 1 is flat, while the lower surface slopes from the left side to the right side in FIG. There is. A hot air blowing slit 30 is provided on the upper surface of the air duct 24 over the entire length in the longitudinal direction. A punching plate 36 is provided that partitions the rectangular cross section of the air duct 24 into an upper second chamber 32 and a lower first chamber 34. A corrugated plate 38 is provided on the upper surface side in FIG. 1 of the punching plate 36 having a large number of small holes. The corrugated plate 38 has a corrugated longitudinal section. An internal duct 40 is provided within the first chamber 34 .

The internal duct 40 is a cylindrical body having a cross-sectional shape smaller than that of the first chamber 34 .

The internal duct 40 is open at the end visible in FIG. 1, but closed at the opposite end. Furthermore, the rear end of the air duct 24 is also closed. The end of the air duct 24 visible in FIG. 1 is closed except for the inner duct 40. The internal duct 40 has a hot air supply slit 42 on the lower side in FIGS. 1 and 2, that is, on the side opposite to the side where the punching plate 36 is arranged. Slide plates 44 (slit width adjustment mechanism) are provided adjacent to and on both sides of the hot air supply slit 42, respectively. The slide plate 44 is movable in a direction that makes the gap between the hot air supply slits 42 variable, and can be stopped and fixed at a desired position.

Next, the operation of this embodiment will be explained.

The fan 20 is rotated by the motor 26, and hot air 46 heated by the heater 22 is supplied from the open end side of the internal duct 40. Hot air 4 supplied into the internal duct 40
6 is supplied to the gap between the internal duct 40 and the first chamber 34 through the hot air supply slit 42 . Next, the hot air 46 passes through the outer periphery of the internal duct 40, further passes through the punching plate 36, and flows toward the second chamber 32. Then,
The hot air 46 flows from the lower surface side to the upper surface side of the corrugated plate 38 and is blown onto the resin film 12 from the hot air blowing slit 30. Thereby, the resin film 12 is heated, and a predetermined stretching is performed by the action of the clip 14. The hot air 46' blown out from the hot air blowing slit 30 has a substantially uniform wind speed along the longitudinal direction of the hot air blowing slit 30. The speed of the hot air 46' blown out from the hot air supply slit 42 of the internal duct 40 increases as it goes deeper from the open end of the internal duct 40, but until it passes through the outer periphery of the internal duct 40 and reaches the punching plate 36. Since the flow is further made uniform by the punching plate 36 and the corrugated plate 38, the wind speed is almost uniform in the longitudinal direction at the stage of blowing out from the hot air blowing slit 30 as described above. becomes. FIG. 5 shows the results of measuring the wind velocity of the hot air 46' blown out from the 3° hot air blowing slit of the air duct 24 according to the present invention, which is opened at each longitudinal position of the slit, and the results of measuring the wind speed of the hot air 46' blown out from the 3° hot air blowing slit of the air duct 24 according to the present invention, and the results of measuring the wind velocity of the hot air 46' blown out from the 3° hot air blowing slit of the air duct 24 according to the present invention. The results of similar measurements are shown using

As you can see from this figure 5, the conventional one has ±4%
It can be seen that while there is some variation in wind speed, in the case of the present invention, it is well uniformed to about ±1%. In this way, since the speed of the hot air 46' is uniform, the resin film 12 is heated uniformly in the width direction, and the resin film 12' can be obtained with high thickness accuracy.

Note that the overall air volume can be adjusted by adjusting the gap between the hot air supply slits 42 using the slide plate 44. Further, the slide plate 44 can be divided into a plurality of parts in the longitudinal direction, and each part can be adjusted independently. In this case, for example, the gap between the hot air supply slits 42 at the back of the internal duct 40 may be made smaller so that the wind speed can be made substantially uniform when the hot air is blown out from the hot air supply slits 42.

(Second Embodiment) A second embodiment is shown in FIGS. 6 and 7. This second embodiment is
The structure of the internal duct 40 is different from that of the first embodiment, and the other configurations are the same as those of the first embodiment. The internal duct 40 is divided into three parts: a first duct chamber 40a1, a second duct chamber 40b, and a third duct chamber 40c. Slits 42a and 42c are provided in the first duct chamber 40a and the second duct chamber 40c, respectively. 3rd duct room 4
The side surface to which the hot air 46 of 0c is supplied is closed.

The rear end surfaces of the first duct chamber 40a, the second duct chamber 40b, and the third duct chamber 40c are closed. Further, the second duct chamber 40b and the third duct chamber 40c communicate with each other at the rear end.

Hot air 46 is placed in the first duct chamber 40a and the second duct chamber 40b.
is supplied. The hot air supplied to the first duct chamber 40a is supplied to the first chamber 34 from the hot air supply slit 42a. On the other hand, the hot air 46 supplied to the second duct chamber 40b flows into the third duct chamber 40c through the communication part on the back side of the second duct chamber 40b, and is supplied to the first chamber 34 from the hot air supply slit 42c. Ru. Therefore, as shown in FIG. 7, on the hot air supply slit 42a side, the wind speed of the hot air 46 is higher on the back side, while on the hot air supply slit 42c side, the wind speed distribution is different from that on the hot air supply slit 42a side. The opposite is true. Therefore, the overall wind speed distribution becomes almost uniform. As a result, the wind speed distribution of the hot air 46' blown out from the hot air blowing slit 30 becomes more uniform, and the variation is within ±1% as in the first embodiment. Note that this second embodiment can also be provided with a slit width adjustment mechanism that can adjust the width dimensions of the hot air supply slits 42a and 42c.

(G) As described in detail, according to the present invention, hot air is supplied through the internal duct provided in the air duct, so the speed of the hot air blown onto the resin film from the hot air blowing slit is The variation in temperature is significantly reduced, and the heating state of the resin film becomes uniform. Thereby, a resin film having a uniform thickness in the width direction can be obtained. Furthermore, by providing a slit width adjustment mechanism that can adjust the gap between the hot air supply slits in the internal duct, the overall air volume can be adjusted. Further, if the slit width adjustment mechanism is configured to be able to adjust the gap in the longitudinal direction of the hot air supply slit, the wind speed can be further made uniform. Furthermore, by providing two hot air supply slits in the internal duct so that the hot air is supplied from opposite directions in the longitudinal direction, the speed of the hot air can be made uniform.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an air duct according to a first embodiment of the present invention, FIG. 2 is a sectional view of the air duct shown in FIG. 1, and FIG.
The figure is a plan view showing the entire horizontal stretching machine for film production, Figure 4 is a sectional view taken along line IV-IV in Figure 3, Figure 5 is a diagram showing the wind speed distribution, and Figure 6 is a diagram showing the second implementation. FIG. 7 is a diagram showing hot air blowing out from the internal duct of the second embodiment. FIG. 8 is a diagram showing a conventional air duct. FIG. 9 is as shown in FIG. FIG. 2 is a cross-sectional view of a conventional air duct. 10...Oven, 12.12'...Resin film, 14...Clip, 16...Hot air supply device, 2
0... Fan, 22... Heater, 24... Air duct, 30... Slit for hot air blowing, 32... Second chamber, 34... First chamber, 36... Punching plate , 38... Corrugated plate, 40... Internal duct, 42...
...Hot air supply slit, 44...Slide plate. Patent applicant: Japan Steel Works, Ltd.

Claims (1)

[Claims] 1. A resin film that is continuously fed through an oven is heated with hot air, both ends of the resin film in the width direction are gripped by clips, and the dimension between the clips is expanded to horizontally move the resin film. This is a hot air supply device for a horizontal stretching machine for producing a film that is stretched in the width direction of the resin film, and includes a cylindrical air duct that is elongated in the width direction of the resin film and is closed at one end, and a cylindrical air duct that is elongated in the width direction of the resin film and that is connected to the resin film at the opposite side of the resin film in the width direction of the resin film. A slit for blowing hot air provided along the slit, a punching plate with a large number of small holes that separates the air duct into a second chamber on the side of the slit for blowing hot air, and a first chamber on the opposite side, and a punching plate and a hole for blowing hot air. In a device that has a corrugated plate installed between the slit and a heater and fan capable of supplying hot air, the first chamber of the air duct has a cross-sectional shape smaller than the cross-sectional shape of the first chamber and equal to the total length of the air duct. A long cylindrical internal duct is provided, and a slit for supplying hot air is provided in the longitudinal direction on the opposite side of the internal duct from the side facing the punching plate, and the hot air is supplied by a heater and a fan. The gap between one end of the internal duct and one end of the air duct is closed so that the hot air is supplied from one end of the internal duct to the inside of this, and the other end of the internal duct is closed. Hot air supply device for horizontal stretching machine for film production. 2. Film manufacturing in which a resin film that is continuously fed through an oven is heated with hot air, both ends of the resin film in the width direction are gripped by clips, and the dimension between the clips is expanded to stretch the resin film in the lateral direction. A hot air supply device for a horizontal stretching machine, which includes a cylindrical air duct that is elongated in the width direction of the resin film and closed at one end, and a hot air provided along the width direction of the resin film at the part of the air duct that faces the resin film. A blowing slit, a punching plate with a large number of small holes that separate the air duct into a second chamber on the side of the hot air blowing slit and a first chamber on the opposite side, and between the punching plate and the hot air blowing slit. In the first chamber of the air duct, an inner duct having an external shape smaller than the cross-sectional shape of the first chamber and a length equal to the total length of the air duct is provided. is provided, and the internal duct is the first duct chamber,
It is divided into three chambers, a second duct chamber and a third duct chamber, and hot air supply slits are provided in the longitudinal direction on the opposite side of the punching plate in the first and third duct chambers. The first duct room, the second duct room
The ends of the duct chamber and the third duct chamber opposite to the side where the fan is arranged are closed, and the second duct chamber and the third duct chamber communicate with each other at the ends opposite to the side where the fan is arranged. , the open ends of the first duct chamber and the second duct chamber are the same as the air duct so that the hot air supplied by the heater and the fan is supplied from the open end side of the first duct chamber and the second duct chamber to the inside thereof. A hot air supply device for a horizontal stretching machine for film production, characterized in that the space between the side end portion and the side end portion is closed. 3. The hot air supply device for a horizontal stretching machine for film production according to claim 1 or 2, further comprising a slit width adjustment mechanism capable of adjusting the width of the hot air supply slit in the internal duct. 4. The hot air supply device for a transverse stretching machine for film production according to claim 4, wherein the slit width adjustment mechanism is capable of adjusting the width of the hot air supply slit also in the longitudinal direction.