JP4941230B2 - Tenter and its abnormality detection method - Google Patents

Description

  The present invention relates to a tenter (or tenter or stretcher) such as a fabric tenter, a film tenter, a plastic film stretcher, or a biaxial stretcher. More specifically, the present invention relates to a tenter that can detect an abnormality in a tenter rail, and a method for detecting an abnormality in a tenter rail in such a tenter.

  The tenter usually has a clip chain positioned along both edges of the sheet-like material in the traveling direction of the sheet-like material, and each of the clips constituting the clip chain grips both edges of the sheet-like material. Along the rail, the sheet-like material is stretched, stretched, heat-treated and the like.

  Therefore, in order to obtain a uniformly processed sheet, it is necessary to securely hold the film with the tenter clip with respect to the correct width and interval, uniformity in the height direction, tension, and the like. However, if the tenter is operated for a long time, a lot of tenter clips will rattle, loosen, mechanically wear, etc., and the clip chain composed of tenter clips that run against the tenter rail will run poorly. Some of them raise and cause poor gripping of the sheet-like material. As a result, the conveyance of the film becomes unstable, causing problems such as uneven processing such as uneven stretching, wrinkles, and film tearing.

In order to solve such a problem, for the purpose of detecting an abnormality that has occurred in the clip chain, an abnormality that has occurred in at least one part of the part that supports the clip chain is detected, and that part is detected at the occurrence timing of the abnormality. A clip chain abnormality detection method that can identify a passing tenter clip has been disclosed (see, for example, Patent Document 1).
JP 2005-41595 A

  The present inventor has studied the above-described abnormality detection method in order to solve the problems such as uneven processing such as stretching unevenness, wrinkles, and film breakage, and as a result, such problems are detected as abnormalities occurring in the clip chain. It has been found that this cannot always be solved sufficiently. Therefore, it is desirable to more reliably solve such a problem.

  As a result of further studies by the inventor in order to solve the above-described problems, it has been concluded that it is important to accurately grasp the abnormality occurring in the tenter rail. In order to grasp the abnormality that occurred in such a tenter rail, for example, a sensor is installed at a location where the tenter rail is located, and a signal generated when the tenter clip passes that location is detected to check for the presence or absence of the abnormality. I came up with a method. However, in this method, it is necessary to place sensors at many locations on the tenter rail. As a result, it takes time to attach and detach the sensor, and the cost for the sensor is also high. On the other hand, if the number of sensors is limited, abnormal locations can be roughly detected, but detailed abnormal locations are difficult to identify, requiring time to detect abnormal locations and making it easy to minimize production loss. is not. Therefore, the inventors have concluded that this method may not always be sufficient.

  Therefore, as a result of repeated examination in consideration of these, the present inventor more efficiently and earlyly detects a tenter rail abnormality in the tenter, preferably a sign of abnormality, thereby causing a serious problem. It has been found that productivity can be improved by implementing measures before, and the present invention has been completed.

  In the first aspect, the present invention is a tenter including a tenter chain and a tenter rail each including a plurality of tenter clips, and at least one tenter clip correlates with the presence or absence of an abnormality occurring in the tenter rail. A tenter having a sensor for detecting a signal is provided.

  In the second aspect, the present invention includes a tenter chain and a tenter rail each including a plurality of tenter clips, and at least one tenter clip detects a signal correlated with the presence or absence of an abnormality occurring in the tenter rail. A method for detecting an abnormality occurring in a tenter rail in a tenter having a sensor, and having a sensor when it is determined that an abnormality has occurred by processing a signal detected by the sensor, or that an abnormality has occurred Provided is a method for detecting an abnormality occurring in a tenter rail, wherein the position of the tenter clip in the tenter rail is determined (and the position is identified as a location where an “abnormality or sign thereof” has occurred).

  In the present invention, the sensor has at least a function of detecting, preferably quantitatively detecting, a signal that correlates with the presence or absence of an abnormality occurring in the tenter rail. Processing of the detected signal may be performed in the sensor itself or may be processed by a processing device different from the sensor. In general, it is preferably processed by another processing device, and a signal is obtained by a sensor, the signal is converted into an electrical signal, or an electrical signal is directly obtained, for example, the signal is wirelessly processed by another processing device. Is preferably transmitted. In this case, the tenter clip has, in addition to the sensor, additional elements necessary for transmitting signals such as, for example, a transmitter for transmitting signals and a power source (if necessary) required for transmission. Such additional elements may be provided on the same tenter clip as the sensor or on a tenter clip adjacent to or adjacent to the tenter clip having the sensor.

  An anomaly that occurs in the tenter rail is a condition that prevents the tenter from operating normally due to the tenter rail.For example, rail rattling, loosening, tilting, mechanical wear, etc. The presence of garbage, clogging of garbage, etc. can be mentioned. The sign of abnormality means a state before the abnormality is reached. The sign of abnormality means the state before reaching the abnormality, and the sign of abnormality is defined by what kind of condition is judged as abnormal, but these are relative concepts, It may be considered that the sign of is included in the abnormality. Accordingly, in the description of the present specification, the term “abnormal” can be read as “sign of abnormality” unless the context is inappropriate.

  The signal correlating with the presence or absence of an abnormality occurring in the tenter rail is detected when the tenter clip passes through the tenter rail in an abnormal state, and the signal passes through the tenter rail in a normal state. It means a signal derived from a physical quantity that is clearly (ie, correlated) with a case where it is detected. Specifically, such a physical quantity is the position of the tenter clip or a physical quantity derived therefrom, for example, the moving speed, acceleration, vibration, etc. of the tenter clip. Such physical quantities are affected by the state of the tenter rail. That is, the physical quantity varies depending on whether the tenter rail is normal or abnormal. A signal derived from such a physical quantity can be obtained as an electrical signal by various sensors. In a preferred embodiment, the signal correlated with the presence / absence of an abnormality occurring in the tenter rail is the vibration of the tenter clip. In the present invention, it is preferable to use various vibrometers as sensors.

  As mentioned above, the tenter of the present invention preferably has a processing device for the signal detected by the sensor, preferably a processing device for receiving the signal wirelessly, and such a device processes the received signal for anomalies. It is preferable to determine the presence or absence or the presence or absence of an abnormality. In a more preferable aspect of the processing apparatus, when it is determined that there is an abnormality or a sign of abnormality, the position of the sensor when a signal that reaches such a determination is detected, and accordingly, the tenter clip having the same is detected. It has a function of determining the position on the tenter rail.

  The determination of whether or not there is an abnormality or whether or not it is in an abnormal state can be performed, for example, as follows: A signal detected by the sensor when the tenter clip travels on a normal tenter rail (that is, normal operation) Time signal) and a signal detected by the sensor when the tenter clip travels on the tenter rail (that is, an abnormal operation signal) is acquired in advance. These signals acquired in advance are compared with the signals detected by the sensor during actual operation of the tenter, and it is determined whether the detected signal corresponds to a signal during normal operation or a signal during abnormal operation. The presence or absence of abnormalities or signs thereof is determined. In addition, when the signals are compared in this way, it may be determined that the detected signal is not an abnormal operation signal, but is not a complete normal operation signal. At this time, the tenter can be determined to be completely in a transitional state between normal operation and abnormal operation. In particular, when the signal is closer to the abnormal operation signal, the tenter may be determined not to be in the normal operation state but close to the abnormal operation state, that is, there is a sign of abnormality. In this case, depending on the degree of the transitional state (for example, if it corresponds to or is very close to the abnormal operation signal), the tenter is stopped after the tenter is operating, or is left as it is before the tenter is operated. Maintenance / inspection, etc. can be implemented to prevent the tenter from operating in an abnormal state.

  In the tenter of the present invention described above, the sensor is preferably mounted on at least one tenter clip. Usually, it is sufficient to provide one sensor. When a plurality of sensors are provided, the sensors are provided at intervals in the tenter chain, preferably at equal intervals.

  The present invention can detect an abnormality or sign of a tenter rail in a tenter, and as a result, can take measures to eliminate the abnormality or sign before a problem occurs, thereby improving the productivity of the tenter. Can do.

  Hereinafter, the present invention will be described in more detail with reference to the drawings as appropriate, but the present invention is not limited only to the embodiments described in the drawings.

  The tenter of the present invention has a clip chain formed by connecting a plurality of clips, and this chain travels along the tenter rail. These elements constituting the tenter may be conventional, and a tenter clip is illustrated in FIG. 1 (viewed from the side). The clip 2 is mounted and fixed on a clip base 5, and the clip lever 3 is supported by a support shaft 7 so as to be rotatable. The sheet-like object is gripped by the gripping portion 6 by the clip lever 3 and the clip base 5.

  FIG. 2 schematically shows a top view of the tenter. A plurality of tenter clips constitute a tenter chain 12, and the chain 12 travels along the tenter rail 14. The chain 12 moves at a predetermined speed from the tenter inlet portion 9a of the tenter 8 toward the tenter outlet portion 9b, reverses at the outlet portion 9b, and returns toward the inlet portion 9a. The sheet-like object 11 moves together while being held by a chain-shaped clip that slides along the tenter rail 14, and passes through the tenter 8 and has a predetermined magnification in the transverse direction (left-right direction, vertical direction in FIG. 2). Stretched.

  A turn wheel 10 is installed at the outlet 9b and the inlet 9a of the tenter 8. When a plurality of tenter clips come to the inlet portion 9a, the clip lever 3 comes into contact with the turn wheel 10 so that the clip is rotated to come into contact with the grip portion 6 by the contraction force of a spring (not shown). The both edges of the object 11 are gripped. The gripped sheet-like object 11 is released from the tenter clip by the turn wheel 10 at the exit portion 9b and sent to the next step.

  The tenter of the present invention is a tenter having the tenter clip chain and the tenter rail as described above, and at least one tenter clip is provided with a sensor for detecting a signal correlated with the presence or absence of an abnormality occurring in the tenter rail. is important.

  Further, the method for detecting an abnormality occurring in the tenter rail of the present invention is the method of detecting a sensor in the tenter of the present invention described above by processing a signal detected by the sensor and determining that there is an abnormality or a sign thereof. The position of the tenter clip having the tenter rail is determined. When this method is used, it is sufficient to provide at least one sensor. Therefore, a large number of sensors are not required, and time is not required for attaching and detaching the sensors. In addition, it is possible to grasp in detail the abnormal part, and it does not take time to detect the abnormal part, so that an abnormality can be detected at an early stage and measures can be taken in advance before a problem occurs. As a result, production loss can be minimized.

  In one aspect, the signal correlated with the presence or absence of an abnormality occurring in the tenter rail can be obtained by detecting the vibration of the tenter clip with a sensor as described above. For example, when a tenter clip having a vibrometer as a sensor passes through a normal tenter rail, the voltage change range as a signal obtained from the vibrometer is within a range of −2.0 to 2.0V. Therefore, it can be determined that an abnormality has occurred when the change width of the voltage measured by the vibrometer exceeds the range of −2.0 to 2.0 V during the actual operation of the tenter.

  However, when the measured voltage change width exceeds the range of −2.0 to 2.0 V, it may be too extreme to immediately determine that an abnormality has occurred. In that case, considering that there is a transitional state (sign of abnormality) that approaches the abnormal state, if the voltage change range is within -2.5 to 2.5 V, there is a possibility that an abnormality will occur. In some cases, it is preferable to determine that an abnormality has occurred when the voltage change width exceeds −2.5 to 2.5 V in the management area. Normally, depending on the tenter to be used, the normal voltage change width is set as needed, and the voltage change width in the management area and the voltage change width regarded as abnormal are the specifications of the sheet material processed by the tenter for that purpose. It can be changed depending on the accuracy.

  As described above, in one aspect, the signal correlated with the presence / absence of an abnormality occurring in the tenter rail is a signal based on the vibration of the sensor, and therefore a vibrometer can be preferably used as the sensor. Vibrometers include non-contact types such as eddy current type, capacitive type, electro-optic type, and Hall element type, and contact types such as piezoelectric type, servo type, strain gauge type, and electrodynamic type. Of these, the contact type is preferable, and the piezoelectric type is more preferable.

  In the present invention, the sensor is disposed on the tenter clip. Accordingly, the abnormality occurring in the tenter rail is directly transmitted to the tenter clip, so that the abnormality can be detected with higher accuracy. In addition, the sensor is preferably of a size that can be loaded on the clip, and the abnormality can be accurately detected without causing a running failure due to the sensor contacting the other part of the tenter during the running of the clip.

  The sensor preferably has heat resistance. In that case, the sensor can be prevented from malfunctioning due to high heat in the tenter. For example, heat resistance up to 120 ° C. is preferable. It is more preferable to use a sensor having heat resistance up to a higher temperature, the time for lowering the temperature in the tenter can be further reduced, and the production time is further improved.

  In the tenter of the present invention, detection of an abnormality occurring in the tenter rail is performed intermittently or continuously when the product is manufactured by the tenter (that is, online) when the heat resistance of the sensor allows. it can. However, in general, when the production of a product is stopped (for example, when the tenter is stopped to maintain the quality of the product, etc.), that is, the tenter is stopped and offline, preferably the temperature in the tenter is lowered. It is preferable to carry out the detection in a heated state (for example, at 120 ° C. or lower). In the tenter of the present invention, when the purpose is to detect an abnormality of the tenter rail when production of the product is stopped, it is preferable that the sensor can be detachably disposed on the tenter clip. In other words, the tenter clip does not have a sensor when the product is manufactured, and may temporarily have a sensor when an abnormality is detected.

Moreover, the method of specifying the location where the “abnormality” has occurred is, for example, as follows:
In a tenter in a normal tenter rail state, a tenter clip on which a vibrometer is placed is positioned at a predetermined point (for example, the preheating process inlet of the tenter) as a start point (ie, zero point), and then the tenter chain is The vehicle is run at a constant speed, the time after start and the voltage measured by the sensor are recorded, and for example, the graph of FIG. 3A is obtained in advance. The horizontal axis of the graph is the distance from the start point. Since the chain runs at a constant speed, it is converted to distance from the time and speed after the start.

  Next, with respect to a tenter having a tenter rail that may have an abnormality, a tenter chain having a tenter clip with a sensor mounted thereon is run in the same manner as described above, and the temporal change in voltage is measured. For example, the graph of FIG. Is obtained. As is apparent, the change width of the voltage becomes large around 3 m. This point means that the sensor vibrated greatly due to an abnormality in the tenter rail. Therefore, this location is identified as an abnormal location.

  In the tenter of the present invention, processing of the signal detected by the sensor and identification of the location of the tenter rail where the abnormality occurred can be performed by a conventional method. For example, electronic processing means such as a personal computer is used as the processing means. Is preferred. For example, by accumulating the detection data, it becomes possible to grasp the abnormality of the tenter rail in more detail.

  An example of the tenter of the present invention is schematically shown in FIG. 4 including the processing device for the signal detected by the sensor. In FIG. 4, the tenter chain includes a tenter clip 2 having a vibrometer 15 as a sensor, a tenter clip 2 ′ having a battery 16, and a tenter clip 2 ″ having a transmitter 17. Have. The vibration meter 15 is preferably large enough to be loaded on a clip. A signal obtained by the vibrometer 15 is transmitted as a radio wave via the transmitter 17 and the transmission antenna 18. In addition, the radio wave transmitted in FIG. 4 is received and processed by a processing device having the receiving antenna 20, the receiver 21, and the signal processing device 22, and the received data is digitized as, for example, a voltage vs distance through an arithmetic unit. Can be accumulated.

  The signal obtained by the vibrometer is transmitted from the transmission antenna 18, but it is preferable to separate the transmission antenna from a conductor (for example, a metal tenter clip) in order to reduce noise due to poor transmission. Furthermore, it is more preferable to attach the transmitting antenna 18 to a resin dummy clip 19 (for example, a nylon resin or glass reinforced epoxy resin tenter clip) from the viewpoint of noise suppression. For example, as shown in FIG. 4, adjacent to a tenter clip (2, 2 ′ and 2 ″) having a vibration meter 15, a battery 16 and a transmitter 17, respectively, a resin tenter clip 19 (one, preferably It is preferable to attach a plurality of them along the transmitting antenna 18. In addition, the aspect using a dummy clip can be used for the method of detecting abnormality before driving a tenter and manufacturing a product.

  The method for detecting an abnormality occurring in the tenter rail of the present invention has the above-described features, and as a result, it is possible to detect an abnormality occurring in the tenter rail before the tenter is started. In addition, it is preferable to detect the abnormality in the so-called off-line in this way from the viewpoint of cost reduction and quality improvement of the sheet-like material, such as suppressing the generation amount of defective products.

  Therefore, the present invention performs in advance a method for detecting an abnormality that occurs in the tenter rail of the present invention, and if there is an abnormality, after eliminating the abnormality or if there is no abnormality, There is also provided a method for producing a sheet-like material characterized in that the sheet-like material is produced by a tenter. This sheet-like material manufacturing method can improve the quality and productivity of the sheet-like material.

  The tenter of the present invention can be suitably applied to a sequential stretching process, for example, when producing a stretched film. Further, in the production of a sequential stretch type film, the tenter of the present invention can be used. For example, a molten polymer extruded from a die is solidified by a cooling roll to be a stretch raw material, and this stretch raw material is stretched to a stretching temperature. Heat and stretch in the longitudinal direction with a roll, then cool, then hold both edges of the film stretched in the longitudinal direction with a tenter clip and introduce it into a transverse stretching apparatus, stretch in the transverse direction under heating, and continue to tension As it is, the orientation is fixed by heat treatment at an appropriate temperature, and then unstretched portions at both ends are removed and wound up by a winder.

(Film production)
A polyethylene terephthalate chip is melted at 280 ° C., discharged from a base after filtration, and cast on a cooling roll to form an unstretched film.

  The unstretched film is conveyed to a roll stretching machine, preheated with a preheated roll of 80 to 90 ° C, stretched 3 to 4 times between rolls having a difference in peripheral speed, and cooled to 30 ° C.

Next, the film is conveyed to a tenter-type transverse stretching machine, stretched three times in the width direction at a temperature of 100 ° C., and subjected to a heat treatment at 230 ° C. to obtain a biaxially stretched film having a thickness of 12 μm.
Thus, the film apparatus which can carry out biaxial stretching of the film sequentially was used.

(Tenter type horizontal stretching machine)
The tenter rail on which the clip chain travels in a tenter including processes capable of preheating, stretching, heat treatment, and cooling has a length of 12.5 m one way. 489 tenter clips are attached to one-side clip chain. The tenter clip travel speed is 10 m / min. The measurement was carried out at a timing at which the temperature in the tenter could be lowered to 120 ° C. or less by replacing the resin flow path foreign material removal filter, or by drawing roller cleaning.

(Sensor and signal transmission)
The following was used. As shown in FIG. 4, the transmitter, vibrometer, and battery were installed in the tenter clip, the receiving antenna was installed along the tenter rail inside the tenter, and the antenna receiver and the signal processor were installed at the tenter outlet. The transmitting antenna was made to be able to transmit radio waves through a resin clip that had been replaced.

1) Transmitter Transmitter for vibration measurement piezo
Model 8344, manufactured by Tateyama Electronics

2) Receiver Receiver for vibration measurement Tateyama Electronics, model 560B

3) Vibration sensor Made by RION, model PV-65

4) Battery Tateyama Electronics, model 1256

5) Data calculator
LOGGERSTATION PL2400 made by NEC

(Determination of abnormality)
Using such a tenter, as described above, when the tenter rail is normal, the tenter chain is moved along the tenter rail to measure the vibration of the tenter clip, and the voltage vs measured at that time is measured. Based on the time and speed, data on the relationship between the voltage and the distance of the tenter rail (the tenter rail preheating step entrance is the zero point of the tenter rail) was obtained, and the graph of FIG. The change width of the voltage generated in the tenter rail in a normal state was −2.0 to 2.0V, and the voltage amplitude was within 4V. As described above, when the tenter rail is abnormal, the voltage change width is −2.5 to 2.5 V or more. Therefore, the abnormality detection voltage change width is set to 5 V or more to indicate whether there is an abnormality. judge.

(Identification of abnormal points)
Next, the vibration of the tenter after actually operating for a long time was measured in the same manner as before (off-line), and the graph of FIG. 3B was obtained. From this result, a voltage amplitude of 5 V or more was confirmed at a location 2.7 to 3.3 m downstream from the zero point of the tenter rail, and this location was identified as an abnormal location on the tenter rail.

(Check the tenter rail parts)
When the tenter rail at a location near 2.7 to 3.3 m from the zero point was observed, film scraps were caught on the rail joint. This was the cause of the tenter rail malfunction. When the tenter chain was moved along the tenter rail and the vibration was measured again after removing the film scraps, a large voltage change was observed even at a location near 2.7 to 3.3 m from the zero point. I was not able to admit.

  The tenter of the present invention does not require a large number of sensors, and therefore does not require time to detach the device. In addition, it is possible to grasp the details of the abnormal part in detail, so that it does not take time to detect the abnormal part, detect the abnormality early, start production, and implement countermeasures before problems occur. Loss can be kept to a minimum, which can greatly contribute to the industry.

It is a figure which shows the outline of a clip. It is a typical top view of a tenter. (A) Voltage vs. normal tenter rail obtained in the example. Graph of distance and (b) voltage vs. tenter rail with abnormality. It is a graph of distance. It is a figure which shows typically an example of the tenter of this invention including the processing apparatus of the signal.

Explanation of symbols

1 ... tenter rail, 2, 2 ', 2''... tenter clip, 3 ... clip lever,
4 ... tenter chain, 5 ... clip base, 6 ... gripping part, 7 ... spindle, 8 ... tenter,
9a ... Tenter entrance, 9b ... Tenter exit, 10 ... Turn wheel, 11 ... Sheet,
12 ... Clip chain, 14 ... Tenter rail, 15 ... Vibrometer, 16 ... Battery,
17 ... Transmitter, 18 ... Transmitting antenna, 19 ... Dummy clip, 20 ... Receiving antenna,
21 ... Receiver, 22 ... Signal processing device.

Claims (7)

  A tenter having a chain constituted by a plurality of tenter clips and a tenter rail, wherein at least one tenter clip has a sensor for detecting a signal correlated with the presence or absence of an abnormality occurring in the tenter rail. Tenter to do.   The tenter according to claim 1, wherein the sensor for detecting a signal correlated with the presence or absence of an abnormality occurring in the tenter rail is a vibrometer.   3. The tenter according to claim 1, further comprising a signal processing device for receiving and processing a signal detected by the sensor wirelessly.   An abnormality that occurs in the tenter rail in a tenter that has a sensor that detects a signal that correlates with the presence or absence of an abnormality that occurs in the tenter rail. A method of detecting an abnormality that occurs in a tenter rail, characterized by determining a position of a tenter clip having a sensor when the signal detected by the sensor is processed and determined to be abnormal. Detection method.   The abnormality detection method according to claim 4, wherein the sensor that detects a signal correlated with the presence or absence of abnormality occurring in the tenter rail is a vibrometer.   6. The abnormality detection method according to claim 4, further comprising a signal processing device that receives and processes a signal detected by the sensor via radio.   After the abnormality detection method according to any one of claims 4 to 6 is performed in advance, if an abnormality exists, after the abnormality is eliminated, or if no abnormality exists, the state is left as it is by a tenter. A method for producing a sheet-like material, characterized in that the sheet-like material is produced by being widened.

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