JP2002179307A - Film splice detecting method and device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a groove portion present in a film splice definitely distinctively from a film impression and the like and reliably irrespective of the width and depth thereof. SOLUTION: For detecting a splice between one film and another extending in a film width direction, while the film 1 is longitudinally unrolled and run, three positions in the film width direction detect a recessed portion 2 in the film 1, and the output of detection signals from all the positions leads to detection of the splice.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for detecting a joint portion of a film and an apparatus used for the method.
Mainly, it is to ensure detection of a joint portion of a film present in a winding roll of a packaging film used in an automatic filling and packaging machine.

[0002]

2. Description of the Related Art A conventional general film connecting portion of a laminated film or a single layer film for packaging is to connect a rear end of one film and a front end of another film to one surface of the film over its entire width. It is formed by connecting the adhesive tapes adhered to each other in an abutting posture, and such a connecting portion is formed in one winding roll of the packaging film wound to a predetermined length, and in most cases, 1 ~ 3
There are about several places.

[0003] By the way, when the packaging film having such a connecting portion is used for an automatic filling and packaging machine, the thickness of the packaging film is increased at the connecting portion due to the presence of the adhesive tape. , Due to the low thermal conductivity of the adhesive tape, etc., where the adhesive tape is present, it is not possible to apply proper heat sealing to the packaging film by ordinary heating and pressing with a heat sealing blade, and
Since the connecting portion depending only on the adhesive strength of the adhesive tape has low liquid-tightness and air-tightness, it has been impossible to provide the connecting portion for packaging of the article to be packaged. Therefore, conventionally, before the connecting part of the packaging film reaches the main functional parts such as the heat sealing blade of the automatic filling and packaging machine and the filling part of the article to be packaged, those main functional parts or the entire packaging machine are deactivated. For this purpose, the unwinding of the spliced portion of the film from the winding roll is usually detected visually.

[0004] By the way, adhesive tapes which have been widely used in the past for connecting portions of packaging films are generally made in dark colors such as red and black, which are greatly different in color from those of packaging films. The width of 10 to 20 mm is noticeable because it extends over the entire width of the packaging film, and therefore, it is relatively easy to detect the connecting portion of the film visually by the operator, but it is also visually detected by the operator. Does not comply with recent demands for automation of packaging operations. Therefore, recently, it has been proposed to control the operation of the packaging machine by automatically detecting the presence of the connecting portion of the packaging film by forming an aluminum vapor-deposited film or other conductive film on the surface of the adhesive tape. Is being put to practical use. However, even with this, the problems of the heat sealability, liquid tightness, etc. as described above due to the formation of the film connecting portion using the adhesive tape still remain. It is impossible to package the article to be packaged by the section, and therefore, it is inevitable that the main functional section and the like of the automatic filling and packaging machine are inoperative with respect to the film joining section.

[0005] For this reason, the applicant has first made a new film in order to impart sufficient liquid-tightness and air-tightness to the film connecting portion, and to make the film connecting portion applicable to the packaging of the article to be packaged. The connecting structure was proposed as Japanese Patent Application No. 2000-285690. This is because the ductile base film layers are joined together at the end portions of the respective laminated films for packaging comprising a thermoplastic stretched base film layer and a sealant layer. The part is folded back to one of the laminated films, and the mutually opposite sealant layers are further joined. In addition, the same connection structure is to join the sealant layers of the laminated films together in a palm-shape manner, and to further join the stretched base film layers facing each other by turning the joint-like joint back to one laminated film side. It can also be achieved by joining stretched or unstretched single-layer films in the same manner.

[0006] Such a film connecting portion has sufficient liquid-tightness and air-tightness, has a high tensile strength, and properly wraps an object to be packaged under excellent heat-sealing properties. Therefore, even if the connecting portion is unwound from the winding roll, the entire automatic filling and packaging machine can be continuously operated without stopping the main functional parts of the automatic filling and packaging machine. Both the work efficiency and the material yield can be greatly improved.

[0007]

However, in the case where an article to be packaged packed in a packaging bag is distributed as a product to the market, the appearance of the packaging bag must be reduced to prevent a reduction in the value of the product. It is necessary to discriminate and remove the packaging bag containing the part from other packaging bags.To do so, it is necessary to accurately determine the timing at which the film joining part fed from the winding roll reaches the main functional part of the automatic filling and packaging machine. Measure
It is inevitable that only the packaging bag including the connecting portion is reliably removed.

[0008] Accordingly, it is necessary to provide a means for outputting a signal and the like when detecting that the film connecting portion reaches a predetermined position of the automatic filling and packaging machine. The connecting portion according to a person's proposal has, for example, a width of 30 to 50 μm and a maximum depth of
Since only a groove of about 20 to 30 μm remains, it has been difficult to accurately detect the existence of the groove by distinguishing it from the surface marks of the packaging film and the like.

Therefore, the present invention utilizes the fact that the film connecting portion continuously extends in a direction intersecting with the length direction of the packaging film or the like, thereby making it possible to reduce the width of the groove existing in the connecting portion, for example, by changing its width. The present invention provides a method and an apparatus for detecting a joint portion of a film, which can be clearly and distinctly detected from a film mark or the like regardless of the depth.

[0010]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for detecting a joint portion of a film, comprising the steps of continuously extending in a direction intersecting a length direction, for example, a direction orthogonal to or obliquely intersecting. This is to detect the joint between the film and another film.During the feeding operation in the length direction of the film, it detects the concave portion or the convex portion of the film at a plurality of positions in the film width direction, and detects all the portions. The connection portion is detected based on the output of the detection signal at the step (1).

According to this method, under the action of one or a plurality of contact type or non-contact type detection means, the concave portions existing in the film at a plurality of positions in the film width direction, that is, in the extending direction of the connecting portion. Alternatively, by detecting the connecting portion by detecting the convex portion and outputting the detection signals at all locations, the concave portion or the convex portion which is present as a surface mark of the film and is not continuous in the width direction of the film is removed. Or, even if a plurality of detection means may detect, as long as all the detection means do not output a detection signal, it is not detected as a connection part, so that film marks and the like are clearly distinguished from the connection part. Thus, only the connecting portion can be reliably detected.

[0012] Here, when the connecting portion is formed by the joints between the films in a palm shape, the connecting portion includes:
Although the small-sized groove as described above will remain,
When the jointed joint is folded back to one film side and further fusion-bonded thereto, a ridge may be formed on the surface opposite to the groove, so in this method, By making it possible to detect either the concave portion provided by the groove portion or the convex portion provided by the ridge, the film connecting portion can be detected from both the front and back surfaces of the film.

By the way, the detection at a plurality of locations of the concave portion or the convex portion of the film can be performed by a single detecting means in addition to the plurality of fixed detecting means. It is necessary to detect a concave portion or a convex portion at a plurality of positions while displacing the film in the width direction of the film or obliquely forward or backward. Further, the detection by the plurality of fixed detecting means is performed by simultaneously operating all the detecting means in relation to the arrangement mode of the fixed detecting means and the extending mode of the connecting portion, or at a time interval. It can be performed by acting.

A film joint detecting device according to the present invention detects a joint between one film and another film, which extends in a direction intersecting the length direction, and detects the joint of a running film. A plurality of contact-type or non-contact-type sensors for detecting a concave portion or a convex portion are provided at positions facing the front or back surface of a running film at intervals in the width direction of the film. . Here, this arrangement mode of the sensors includes a case where a plurality of sensors are arranged at intervals only in the width direction of the film, and an interval in both the film width direction and the film traveling direction. It is also assumed that it is arranged in the same manner. In this detection device, for a film traveling at a predetermined speed in a certain direction,
When all of the plurality of fixed sensors arranged at intervals in the width direction of the film detect a concave portion or a convex portion at the same time or at a predetermined time interval, the concave portion or the convex portion is By assuming that it exists in the connecting portion extending continuously in the direction intersecting with the width direction of the film, one or more of the fixed sensors separately and independently detects a film mark or the like without mutual relation Can be clearly distinguished, and the connection portion of the film can be reliably detected.

By the way, as the sensor here,
For example, in addition to the contact type that uses a stylus in combination with a piezoelectric element or a strain gauge, a photoconductive cell, a photodiode, a Si photodiode, a phototransistor, a phototransistor used as a non-contact type detector for surface marks, etc. A doubler tube or the like may be used, or a sensor for determining a change in the intensity distribution of diffusely reflected light with respect to the concave portion or the convex portion, a sensor for determining a change in the reflection angle of the fine beam, or the like may be used. Further, another detection device of the present invention includes:
In particular, one sensor that detects the concave portion or the convex portion of the running film, at a position facing the front or back surface of the running film, in the width direction of the film, or
It is arranged to be displaceable diagonally forward or backward.

In this apparatus, one sensor is moved at a constant speed at an appropriate speed in the film width direction or diagonally forward or backward in relation to the extending direction of the film connecting portion and the traveling speed of the connecting portion. In addition, regular detection of a concave portion or a convex portion is performed at a plurality of locations during the movement, and when a concave portion or a convex portion is detected at all detection locations, the concave portion or the like exists in the connecting portion. By doing so, it is possible to reliably detect the film joining portion in the same manner as described above. Therefore, for example, when a film having a film connecting portion is applied to an automatic filling and packaging machine by using the film as a packaging film, after the connecting portion is detected, a packaging bag made after a lapse of a predetermined time, By removing it from another packaging bag, it is possible to sufficiently remove the possibility that the packaging bag including the connecting portion may be mixed into the other packaging bag.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing an embodiment of a detection device according to the present invention,
In the drawing, reference numeral 1 denotes a film, and 2 denotes a groove existing at a joint portion of the film 1, and the groove 2 extends in a direction orthogonal to the length direction of the film 1, that is, in the film width direction. Further, it is assumed that the film 1 is unwound from a winding roll and travels in its length direction as shown by an arrow A in the figure.

Here, the three contact type sensors 3, 4, and 5 are fixed and arranged so as to be opposed to the surface of the film 1 where the groove 2 exists, and are aligned in the film width direction. 3, 4, and 5, a stylus 6 protruding from the rear side to the front side in the running direction of the film 1 and a displacement of the stylus itself caused by the tip of the stylus 6 dropping into the groove 2 or the like. And a combined structure with the piezoelectric element 7.

Here, these contact type sensors 3,
A detection signal generated by the tip of the stylus 4 or 5 falling into the groove 2 or the like is output via the amplifier 8, and all the sensors 3, 4, and 5 are simultaneously output as shown in FIG. By outputting the detection signal, it is detected that the groove 2 of the film connecting portion has passed the position where the sensors 3, 4, and 5 are provided. Therefore, if only one or two sensors output the drop detection signal, it is determined that the cause is a film mark or the like, and is distinguished from the passage through the groove 2. .

Each of the contact sensors 3, 4, 5
Are arranged in the film width direction as described above, the groove 2 of the film connecting portion extends obliquely linearly with respect to the film width direction, for example, as shown by a virtual line L in FIG. If there is, a time interval corresponding to the running speed of the film 1 occurs between the detection signals of the grooves by the respective sensors 3, 4, and 5, for example, as shown in FIG. When the time interval is a predetermined one, it can be detected that the groove has passed. This is because the tip positions of the stylus 6 of the sensors 3, 4, and 5 described above are sequentially offset in the running direction of the film 1 as shown in FIG. The same applies to the case of detecting the groove 2 extending to the groove.

On the other hand, under the apparatus configuration shown in FIG.
When detecting the groove 2 extending in an inclined posture corresponding to the tip of the stylus of each of the sensors 3, 4, and 5,
Each of the sensors 3, 4, and 5 simultaneously outputs a detection signal as shown in FIG. In addition, the groove 2
When the inclination angle with respect to the film width is different from the line connecting the tip of each stylus, each sensor 3,
Nos. 4 and 5 output detection signals at some intervals.

By the way, such a contact-type sensor is
For example, a non-contact type sensor using a Si photodiode as a sensor can be used. In this case, each of the plurality of Si photodiodes is positioned at the stylus tip position as shown in FIG. 1 or as shown in FIG. Relative arrangement, such as the stylus tip position, where each Si photodiode receives reflected light from the film surface with respect to irradiation light from the front side or the back side in the film running direction, and the reflected light is disturbed by grooves etc. The decrease in the amount of light received by the Si photodiode due to the
For example, output through an amplifier and a differentiating circuit, when the expected peaks appear in the differential outputs of all the Si photodiodes, and assuming that the groove of the film connecting part has passed, the groove It can always be reliably detected by distinguishing it from a mark or the like.

FIG. 5 is a schematic plan view showing another embodiment, in which only one contact type or non-contact type sensor is provided. One sensor is displaced at a speed corresponding to the extending direction of the groove portion 2 of the connecting portion, and the passage of the groove portion is determined when the groove portion or the like is detected at all times during the detection operation at a predetermined timing.

FIG. 5A shows a case where the sensor 11 detects the presence of a groove or the like at its initial position when the groove 2 extends in the film width direction, and
The detection at a plurality of locations is sequentially performed at a predetermined timing while moving the film 1 obliquely forward with respect to the running direction of the film 1. The one shown in FIG. The groove 2 extending obliquely with respect to
11 are sequentially detected along the groove 2 while moving relatively obliquely rearward. FIG.
FIGS. 3C and 3D sequentially detect the groove 11 extending obliquely while displacing the sensor 11 in the film width direction. In any of these cases, the groove portion in the connecting portion can be accurately detected by distinguishing it from the surface mark or the like.

In the above, the case where the groove 2 existing in the film connecting portion is detected has been described. However, a convex portion which may occur on the back surface side of the film can be detected in the same manner.

[0026]

As described above, according to the present invention, regardless of the size of the concave portion or the convex portion existing in the film connecting portion, the film connecting portion can be clearly distinguished from the film mark or the like and can be reliably detected. .

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of a detection device according to the present invention.

FIG. 2 is a graph showing detection output signals from respective sensors when a groove is detected.

FIG. 3 is a graph showing detection output signals from respective sensors when a groove is detected.

FIG. 4 is a schematic perspective view showing another embodiment.

FIG. 5 is a schematic plan view showing still another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Film 2 Groove part 3, 4, 5 Contact type sensor 6 Touch probe 7 Piezoelectric element 8 Amplifier 11 Sensor

Claims (8)

[Claims] 1. A method for detecting a connecting portion between one film and another film, which extends in a direction intersecting with the length direction. The method for detecting a joint portion of a film, comprising detecting a concave portion or a convex portion of the film at a plurality of locations, and detecting a joint portion by outputting detection signals at all locations. 2. The method according to claim 1, wherein a plurality of detecting means detect the concave portion or the convex portion of the film at a plurality of locations.
3. The method for detecting a film joint according to 1. 3. The method according to claim 2, wherein the detection of the concave portion or the convex portion is performed simultaneously or at an interval by a plurality of detecting means. 4. The method according to claim 1, wherein the detection of the concave portion or the convex portion of the film at a plurality of positions is performed by one detecting means. 5. The method according to claim 4, wherein the detecting means detects the concave portion or the convex portion at a plurality of positions while displacing one detecting means in the film width direction or obliquely forward or backward. 6. A device for detecting a joint portion between one film and another film, which extends in a direction intersecting with the length direction, wherein the sensor detects a concave portion or a convex portion of a running film. A film connecting portion detecting device, which is disposed at a position facing a front surface or a back surface of a running film at intervals in a width direction of the film. 7. The film joint detecting device according to claim 6, wherein a plurality of sensors are arranged at intervals in a running direction of the film. 8. A device for detecting a joint between one film and another film, extending in a direction intersecting with the length direction, wherein the device detects a concave portion or a convex portion of a running film. A film connecting portion detecting device, wherein the sensor is disposed so as to be displaceable in the width direction of the film or diagonally forward or backward at a position facing the front surface or the back surface of the running film.