JP3386564B2 - Apparatus and method for preventing winding of stenter tear film - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and a method for preventing a torn film from being caught in a stenter for stretching a plastic film in the width direction.

[0002]

2. Description of the Related Art Conventionally, both sides of a plastic film in the width direction are gripped by clips, and the plastic film is stretched in the width direction while continuously passing through an oven, and then the grip of the clip is released at the exit of the stenter. Thus, there is widely known a lateral stretching device (stenter) for a plastic film that causes a clip to circulate toward the stenter inlet side.

In such an apparatus, the film may be torn due to some cause especially in the oven. If the film is torn, the torn film may get caught in the clip and get caught in the device. When the torn film is caught inside the apparatus, it is necessary to immediately stop the production and remove the torn film.

However, once the torn film is caught in the apparatus, it is not easy to remove it and it takes a lot of time and labor to restart the production.

In order to prevent the torn film from being caught as described above, it has been proposed to attach a take-up prevention plate to the clip itself so as to prevent the torn film from being caught (for example, Japanese Utility Model No. 4- 38982).

[0006]

However, in the above-mentioned proposal, although some effect can be exerted on the wrapping of the torn film at the film holding portion of the clip, for example, the torn film is the entire clip. When it is entangled so as to wrap it, the effect of preventing entrapment cannot be exerted at all.

Further, in the above-mentioned proposal, since it is necessary to attach a roll-in prevention plate to each of the clips provided with several hundreds to several thousands in one stenter, it is necessary to remodel the existing equipment so that it can be remodeled. It takes time, labor and money.

The present invention focuses on the above problems,
It is an object of the present invention to provide a stenter tear film roll-in prevention device and a method thereof which can reliably prevent the roll-up film roll-in and can be implemented at low cost.

[0009]

According to the present invention, there is provided a stenter tear film entanglement preventive device for gripping both sides of a continuously running plastic film in the width direction by clips at the stenter inlet. After stretching the film in the width direction in an oven, in a lateral stretching device for a plastic film in which the grip is released at the stenter outlet to orbit the clip toward the stenter inlet side, at the stenter outlet, the film is torn. It is provided with a tear detection means for detecting, and an air nozzle for injecting air on the basis of a signal from the tear detection means and blowing the tear film in a direction away from the clip being run by the jet air.

The air nozzle is, for example, a first air nozzle provided at the clip traveling direction reversal portion of the stenter outlet portion and on the front side of the clip. The air injection direction of the first air nozzle is set to a direction toward the central portion of the stenter in the device width direction through the film engaging portion of the clip.

The air nozzle is composed of a second air nozzle provided on the back side of the clip during traveling at the exit of the stenter. The air injection direction of the second air nozzle is
It is set in a direction toward the central portion in the device width direction of the stenter through the clip.

Further, a cover for covering the clip during traveling is usually provided at the outlet of the stenter, and the air blown from the second air nozzle smoothly passes through the clip through the cover, and In order to effectively inject air against the torn film that tries to wind around the cover,
It is preferable to provide an opening having a wire mesh through which the blast air is passed.

If a stand extending in the width direction of the stenter is provided at the exit of the stenter, the stand may be
It is desirable to provide a third air nozzle that injects air toward the film traveling direction.

The first air nozzle, the second air nozzle, and the third air nozzle are preferably flat nozzles in order to obtain a high directivity of the injection air and a high air injection speed with a small amount of air. . Further, a photoelectric sensor can be used as the breakage detecting means.

Using the above-mentioned apparatus, the method for preventing the inclusion of a stenter tear film according to the present invention is carried out. In this method, both sides in the width direction of a plastic film that is continuously run are gripped by clips at the stenter inlet, the film is stretched in the width direction in an oven, and then the grip is released at the stenter outlet. When circulating the clip to the stenter inlet side, at the stenter outlet portion,
A method is characterized in that breakage of the film is detected, air is ejected from an air nozzle based on the breakage detection signal, and the breakage film is blown away by the ejected air in a direction away from a running clip.

[0016]

In the above-described device for preventing roll-in of the stenter torn film, when the film is torn in the oven or the like, the film tear is surely detected by the film tear detection means and a signal is issued from the film tear detection means. The air is ejected from the air nozzle based on the signal. Since the air from the air nozzle is jetted in a direction of moving the tear film away from the running clip, the tear film is blown away by the jet air and moved in a direction of moving away from the clip. Therefore, the torn film is sequentially removed in the direction in which the torn film is surely moved away from the running clip, and the torn film is prevented from being caught in the clip.

The prevention of the torn film from being caught up is mainly achieved by the first air nozzle and / or the second air nozzle.

By providing the first air nozzle, air is jetted directly to the film engaging portion of the clip, so that the tear film is surely blown off from the film engaging portion of the clip, and the film is stretched in the width direction of the stenter. Excluded towards the center.

Further, by providing the second air nozzle, air is jetted from the back side of the clip during traveling at the exit of the stenter, so that, for example, a torn film entangled in the front side of the clip is easily blown off. ,
It is removed toward the central portion in the width direction of the stenter device.

Further, the cover for covering the running clip is provided with an opening through which the jetting air from the second air nozzle passes, and by providing a wire mesh in the opening, the jetting air from the second air nozzle spreads over a wider range, In addition to preventing the clip from being caught, the cover can be prevented from being caught at the same time.

When a frame extending in the width direction of the stenter is provided at the exit of the stenter, the tear film tries to accumulate on the frame, but by providing the third air nozzle described above, The torn film that tries to accumulate in the stack is discharged from the top of the mount to the front of the mount. Therefore, the processing of the torn film at the time of occurrence of trouble is facilitated, and the time until restarting is greatly shortened.

Further, since the first, second and third air nozzles are composed of flat nozzles, the air is efficiently ejected only to the torn film, so that the torn film is blown more reliably in the desired direction. Be done. Further, since the flat nozzle can achieve good directivity and jet speed with a small amount of air, the torn film can be reliably removed in the desired direction efficiently.

Further, in the method for preventing the roll-in of the stenter tear film according to the present invention, when the grip of the film is released at the exit portion of the stenter and the clip is circulated to the inlet side of the stenter, a tear detection means at the exit portion of the stenter is provided. Due to
Film breakage is reliably detected. Air is ejected from the air nozzle based on the signal from the tear detection means only when the film tear is detected. The blast air is jetted in the direction of moving the tear film away from the running clip, and since the tear film is moved away from the running clip by the air, the tear film can be reliably and effectively caught in the clip. To be prevented.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. 1 to 3 show a stenter tear film entanglement prevention device according to an embodiment of the present invention. In the figure, 1 indicates a plastic film which is continuously run. Examples of the plastic film 1 include polyester film, polypropylene film, nylon film, polyethylene film and the like. The stenter 2 includes a clip 3 for gripping both sides of the traveling plastic film 1 in the width direction at the stenter inlet 2a, and an oven 4 through which the film 1 gripped on both sides by the clip 3 passes.

A large number of clips 3 are provided on both sides of the plastic film 1 along the traveling direction of the plastic film 1, and are driven by an endless annular chain 5 to rotate as shown by the solid arrow in FIG. By setting the running trajectory of the clip 3 to the end,
In the oven 4, the plastic film 1 is stretched in the width direction. The stretched plastic film 1 is
At the stenter outlet portion 2b, the clip 3 is released from the grip and sent to the next step.

The clip 3 from which the grip of the plastic film 1 has been released at the stenter outlet 2b has its direction reversed by the clip traveling direction reversing unit 7 which will be described later.
It is configured so as to go around again toward the stenter inlet portion 2a.

Above the stenter outlet 2b, there is a photoelectric sensor 6 as a breakage detecting means for detecting breakage or perforation of the plastic film 1 stretched in the oven 4.
Is provided.

A first air nozzle 8 is provided at the clip traveling direction reversing portion 7 of the stenter outlet portion 2b and on the front side of the clip 3. The first air nozzle 8 is composed of flat nozzles 8a and 8b arranged in the clip traveling direction. The first air nozzle 8 is configured to inject air based on a signal from the photoelectric sensor 6. Air jetted from the first air nozzle 8 is jetted in a direction toward the center portion in the width direction of the device through the film engaging portion 3a of the clip 3.

A cover 11 is provided at the stenter outlet portion 2b, and the clip 3 and the clip traveling direction reversing portion 7 traveling on the stenter outlet portion 2b are covered by the cover 11.

Inside the cover 11, a second air nozzle 9 is provided in addition to the first air nozzle 8. The second air nozzle 9 is provided on the back side of the clip 3 that travels on the film side, and the second air nozzle 9 is also configured as a flat nozzle. The second air nozzle 9 injects air from the back surface of the clip 3 traveling toward the clip traveling direction reversing portion 7. The air injection direction is set through the clip 3 so that the torn film is directed toward the widthwise central portion of the device (stenter) and obliquely forward in the film running direction. Of the cover 11,
An opening 12 is provided at a position corresponding to the air injection direction of the second air nozzle 9, and the wire mesh 13 is provided in the opening 12.
Is provided. A part of the jet air jetted from the second air nozzle 9 is jetted toward the outside of the cover through the opening 12 of the cover 11. Like the first air nozzle 8, the air from the second air nozzle 9 is configured to be ejected based on the signal from the photoelectric sensor 6.
It should be noted that the cutout 1 is provided at a portion of the cover 11 at the exit of the stenter and on the side of the film so that the blast air can be reliably directed in a predetermined direction and a large area can be blown to the film.
5 are provided.

A pedestal 14 extending in the device width direction of the stenter 2 is provided between the left and right reversing portions 7 of the stenter outlet portion 2b and below the traveling film 1.

A third air nozzle 10 for injecting air toward the film running direction is provided on the frame 14. The third air nozzle 10 is also a flat nozzle. The jet air from the third air nozzle 10 is configured to be jetted based on a signal from the photoelectric sensor 6 as in the case of the first air nozzle 8 and the second air nozzle 9.

Although pressurized air is supplied to each of the air nozzles 8, 9 and 10 from a factory compressed air source or the like, in order to stabilize the supply, a buffer tank (not shown) is provided on the upstream side of the nozzles. Is preferably provided.

In the apparatus as described above, the oven 4
In the drawing process of the plastic film 1 in the inside,
When the film is torn for some reason, the torn film tries to get caught in the clip 3 or the like at the stenter outlet portion 2b. If the clip 3 travels to the clip traveling direction reversal portion 7 while the clips 3 on both sides are torn and grips the film, the tear film may be caught in the clip traveling direction reversal portion 7.

However, in the roll-in prevention device for the stenter tear film according to the present embodiment, first, the tear of the plastic film 1 is detected by the photoelectric sensor 6 provided at the stenter outlet portion 2b as a tear detection means. Based on the breakage detection signal from the photoelectric sensor 6, each air nozzle 8,
Air is jetted from 9, 10.

The first air nozzle 8 has a stenter outlet 2
It is provided on the clip front surface side of the clip traveling direction reversing portion 7 of b, and its air injection direction is set to be a direction toward the central portion of the stenter 2 in the device width direction through the engaging portion 3a of the clip 3. Therefore, the air is jetted directly to the torn film that is entangled in the vicinity of the engaging portion 3a of the clip 3 or is about to be entangled, so that the torn film is blown off from the clip 3 and is surely moved in the device width direction of the stenter 2. It is discharged toward the center.

Further, since the first air nozzle 8 is constituted by the flat nozzle as described above, the jet air is jetted precisely in the set direction, and the force by the jet air is concentrated and efficiently. Works well on torn films. As a result, the air blown from the first air nozzle 8 is efficiently torn and hits the film, and the torn film is effectively acted on by the expulsion force, and the torn film is efficiently blown away and prevented from being caught in the clip 3. .

The second air nozzle 9 has a stenter outlet 2
It is provided on the back side of the clip 3 that is traveling toward the clip traveling direction reversing portion 7 of b. The air ejection direction of the second air nozzle 9 is set so as to face the central portion of the stenter 2 in the device width direction from the back side of the clip 3 through the clip 3. Therefore, the tear film is clip 3
Even when trying to entangle the clip 3 from the front surface thereof, the film is torn by the air blown from the second air nozzle 9 and the film is surely blown toward the central portion of the stenter 2 in the device width direction.

Since the second air nozzle 9 is also formed as a flat nozzle, the jet air can be accurately broken and applied to the film.

Further, a part of the air jetted from the second air nozzle 9 flows out to the outside through the wire mesh opening 12 of the cover 11. Therefore, for example, even when the torn film is about to wind around the cover 11, the torn film is surely blown by the air blown from the second air nozzle 9 and blown out from the opening 12, and the torn film is surely blown to this portion. The wrapping of the film is prevented.

The tear film blown off by the air blown from the first air nozzle 8 and the second air nozzle 9 as described above is provided at the central portion in the device width direction of the stenter 2, that is, below the stenter outlet portion 2b. It is discharged onto the gantry 14. A third air nozzle 10 for injecting air toward the film traveling direction is provided on the frame 14.

Therefore, the tear film discharged onto the gantry 14 is discharged to the front of the gantry 14 by the air blown from the third air nozzle 10 and a large amount of staying on the gantry 14 is prevented. Therefore, the torn film can be easily removed, and the processing when trouble occurs is facilitated, so that the time until the apparatus is restarted can be greatly shortened.

Since the third air nozzle 3 is also composed of a flat nozzle, it is possible to efficiently apply the jetting air to the torn film on the frame 14 and to reliably discharge the torn film in a desired direction.

The first air nozzle 8, the second air nozzle 9, and the third air nozzle 10 are each configured to inject air on the basis of a signal from the photoelectric sensor 6 as a breakage detecting means. Therefore, the air is ejected from the air nozzles 8, 9 and 10 only when the plastic film 1 is broken, so that the reliability of the apparatus can be secured.

In this embodiment, the photoelectric sensor 6 is used as the breakage detecting means, but it is also possible to use another sensor such as an ultrasonic sensor. Further, although the air nozzles 8, 9, 10 are flat nozzles in this embodiment, other types of nozzles may be used.

The entrainment prevention method according to the present invention is carried out in the following manner by using the embodiment apparatus constructed as described above. When the plastic film 1 is torn in the oven 4, the torn is detected by a photoelectric sensor 6 as a tear detecting means provided at the stenter outlet 2b. When the photoelectric sensor 6 detects a break, the photoelectric sensor 6
Signal is emitted from the first air nozzle 8 and the second air nozzle 9 emits air based on the signal. The torn film is kept away from the running clip 3 and the cover 11 by the jet air, and the torn film is prevented from being caught in the clip 3 and wound around the cover 11.

The torn film blown off by the jet air at the stenter outlet portion 2b as described above is mainly blown off on the frame 14 extending in the width direction of the stenter in this embodiment.

The torn film on the pedestal 14 is a third air nozzle 10 and a second air nozzle 9 for injecting air in the film traveling direction based on a signal sent from the back and a signal from the photoelectric sensor 6. Is discharged from above the pedestal 14 to the front floor surface or the like.

In the above-described method for preventing the roll-in of the stenter tear film, air is jetted from the air nozzles 8, 9 and 10 based on the signal from the photoelectric sensor 6, so that the tear occurs in the film 1. Only the torn film is reliably blown off by the blast air and the clip 3
Be excluded from. Further, since the air jet directions of the air nozzles 8, 9 and 10 are all directed to the direction in which the tear film is distant from the clip 3, a highly reliable method for preventing the inclusion of the stenter tear film can be realized.

[0050]

As described above, in the roll-in prevention device for a stenter tear film according to the present invention, the tear detection means for detecting the tear of the film at the exit of the stenter and the signal from the tear detection means are used. By injecting air, the air is provided with an air nozzle that blows away in a direction away from the running clip by tearing the film, so that tearing of the film can be reliably detected, and by air jetting performed based on the tear detection signal, Engagement can be reliably and quickly prevented. Therefore, it is possible to realize a highly reliable stenter tear film entanglement prevention device.

Further, since the first air nozzle is provided, the air can be directly and effectively jetted to the film engaging portion of the clip, so that the tear film can be surely blown from the film engaging portion of the clip, and the tear film can be blown. Can be efficiently removed toward the central portion of the stenter in the device width direction, and the film can be reliably prevented from being caught.

Further, by providing the second air nozzle, air is jetted from the back surface of the clip during traveling,
Even when the torn film is trying to be entangled in the front of the clip in a complicated manner, the torn film can be blown away to surely move away from the clip, and the film can be reliably prevented from being caught.

Further, the cover for covering the running clip is provided with an opening through which the jet air from the second air nozzle passes, and by providing a wire mesh in the opening, the jet air from the second air nozzle is blown out in a wider range. It is also possible (for more widespread use) to ensure that the torn film is blown off even if it is about to be wrapped around the cover.

Further, by providing the third air nozzle on the frame extending in the width direction of the stenter at the exit of the stenter,
The torn film accumulated on the frame can be quickly discharged to the front of the device. Therefore, when the trouble occurs, the tear film processing is facilitated, and the time until the apparatus is restarted can be greatly shortened.

Further, by constructing each air nozzle from a flat nozzle, it is possible to efficiently eject air in a desired direction. Further, the desired air nozzle can be easily installed in a narrow space such as the inside of the cover.

Since the entanglement prevention device according to the present invention is not provided for each of a large number of clips but can be easily and inexpensively installed, it can be easily applied to existing equipment. it can.

Further, according to the method for preventing the roll-in of the stenter tear film according to the present invention, the film tear can be surely detected by the tear detection means, and the air injection from the air nozzle based on the signal from the tear detection means ensures the film tear. It is possible to prevent the torn film from being caught in the clip.

[Brief description of drawings]

FIG. 1 is a schematic plan view of a roll-in prevention device for a stenter tear film according to an embodiment of the present invention.

FIG. 2 is a front view of the device of FIG. 1 taken along the line II-II.

3 is a partially enlarged perspective view of a stenter outlet portion of the apparatus of FIG. 1. FIG.

[Explanation of symbols] 1 plastic film 2 stenter 2a Stenter entrance 2b Stenter exit 3 clips 3a biting part 4 oven 5 Endless circular chain 6 Photoelectric sensor as breakage detection means 7 Clip running direction reversing part 8, 8a, 8b First air nozzle 9 Second air nozzle 10 Third Air Nozzle 11 cover 12 openings 13 wire mesh 14 mounts 15 notches

Continuation of the front page (56) Reference JP-A-4-191647 (JP, A) JP-A-62-18242 (JP, A) JP-A-5-42591 (JP, A) Actual Kaihei 1-88660 (JP , U) Actual Kaihei 3-126621 (JP, U) Special Tables 6-503524 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B65H 43/08 B29C 55/08 B29C 55/20 B65H 23/028

Claims (8)

(57) [Claims] 1. A plastic film which is continuously run is gripped on both sides in the width direction by clips at the inlet of the stenter, the film is stretched in the width direction in an oven, and then the grip is released at the outlet of the stenter. In a lateral stretching device for a plastic film that circulates a clip to the inlet side of the stenter, a tear detection means for detecting a tear of the film and air is jetted based on a signal from the tear detection means at the exit portion of the stenter. An air nozzle that blows away the torn film from the running clip in a direction away from the running clip by the jetting air, and a stenter torn film entanglement prevention device. 2. The air nozzle has a first air nozzle, and the first air nozzle is provided at a clip traveling direction reversal portion of the stenter outlet portion and on the front side of the clip,
2. The stenter breakage film entrainment prevention device according to claim 1, wherein an air injection direction of the first air nozzle is set to a direction toward a central portion in a device width direction of the stenter through a film engagement portion of a clip. 3. The air nozzle has a second air nozzle, and the second air nozzle is provided on the back side of a clip that is running at the exit of the stenter, and the air injection direction of the second air nozzle is The device for preventing roll-in of a stenter tear film according to claim 1 or 2, which is set in a direction toward a central portion in the device width direction of the stenter through a clip. 4. A cover for covering the running clip is provided at the outlet of the stenter, and the cover is provided with a wire mesh opening through which the air blown out from the second air nozzle passes. The device for preventing the roll-in of the film from the stenter according to claim 3, which is provided. 5. A frame that extends in the width direction of the stenter is provided at the exit of the stenter, and a third air nozzle that injects air toward the film traveling direction is provided on the frame. Item 5. An apparatus for preventing inclusion of a stenter tear film according to any one of Items 1 to 4. 6. An apparatus for preventing inclusion of a stenter tear film according to claim 1, wherein the air nozzle is a flat nozzle. 7. The roll-in prevention device for a stenter tear film according to claim 1, wherein the tear detection means is a photoelectric sensor. 8. A plastic film which is continuously run is gripped on both sides in the width direction by clips at the stenter inlet, the film is stretched in the widthwise direction in an oven, and then the grip is released at the stenter outlet. When the clip is circulated to the stenter inlet side, at the stenter outlet portion, the tear of the film is detected, air is jetted from the air nozzle based on the tear detection signal, and the jet air blows the film while running. A method to prevent the film from getting caught in the stenter tear film, which is characterized by blowing away in a direction away from the clip.