JP2852141B2 - Apparatus for forming tear lines on laminated films - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a laminated film comprising at least one plastic film layer,
The present invention relates to an apparatus for forming a tear line composed of a dashed melted portion of a trace, that is, a tear induction line,
This makes it very easy to change various dimensions of the tear line.

[0002]

2. Description of the Related Art A technique of forming a weak line as a tear line by using a laser beam on a specific layer of a laminated film under the relative movement of the laser beam and the laminated film is disclosed in, for example, US Pat. No. 3,790,744. Description and 3909582
It is also known from this document that it is also known that the line of weakness is constituted by a dashed melt-evaporation section of traces.

[0003] Here, in the case where a weak line consisting of a broken-line-shaped fusion zone is formed in a laminated film made as a packaging bag, the easy-opening property of the packaging bag is sufficiently ensured. By selecting the length of the part and other dimensions, it is possible to increase the tensile strength of the bag as required compared to the weak line consisting of a continuous fused part, The advantage that the bag can be effectively prevented from stretching at the weak point when filling the object, and the gas barrier property of the bag can be easily controlled by selecting the contour area of each dashed fusion zone. There is.

[0004]

By the way, in such a conventional technique, various dimensions of the weak line are changed, for example,
The fusion depth and fusion width of each fusion zone can be changed by adjusting the laser output and the position of the condenser lens, respectively.Also, the length of each fusion zone and the mutual interval of each fusion zone can be changed. the adjustment of the relative speed between the laser beam and the laminate film or, by light shutter provided to the laser beam source, it intends row by adjusting the beam generation time and beam generation interval is required respectively, which therefore, routine and country Frequent changes in the length of the weld and the spacing between the welds often require fine and precise adjustments of the laser system and / or related parts that must be left to the technician. Will be forced to do so.

Therefore, when the weak line is formed in a slitter work process or an automatic filling work process in which the elderly, a part-time housewife or the like is the main worker, the length of the fusion zone and the interval between the fusion zones are changed. There was a problem that it was difficult to do even accurately.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and is intended to change the dimension of a tear line formed by a broken-line fusion zone, in particular, to change the length of the fusion zone and the interval between the fusion zones. An object of the present invention is to provide an apparatus for forming a tear line in a laminated film that can be easily and accurately performed by anybody without requiring any adjustment to a beam irradiation path as well as a beam generation source.

[0007]

The apparatus for forming a tear line in a laminated film according to the present invention is, in particular, rotatably driven about an axis substantially parallel to the laser beam between a laser beam generating means and the laminated film. Te, at least a part of the laser beam, blocking intermittently the laminated film, provided with at least one of the rotary light shielding plate, the laser the rotary light shielding plate
The beam is tapered and can be moved forward and backward.
It was a good thing.

[0008]

In this tearing line forming apparatus, the length of each fusion zone and the interval between the fusion zones formed in broken lines are changed by the number of light shielding plates provided completely independently of the laser system.
The rotation speed of the light-shielding plate, the width of the light-shielding plate,
By adjusting the advance / retreat position or the like with respect to the user beam selectively or in an appropriate combination, anyone can easily, accurately, and safely perform the operation without relying on a technician.

Further, in this device, the relative position between the laser beam and the light shielding plate is adjusted by changing the advancing / retreating position of the tapered light shielding plate, and only a part of the laser beam is intermittently blocked at the tip of the light shielding plate. By this, the intensity of the beam irradiated on the laminated film can be increased, and according to this, although it is continuous in plan view, a tear line in which the melting depth alternately becomes shallow is formed. Can be. Such tear lines of uniform depth, enough known continuous pull tear line, without greatly damaging the laminate film, as compared with the simple dashed shaped tear line, tear be made makes it easier For this reason, in processing the tear line, the allowable dimensional error of each part of the tear line can be increased.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic perspective view showing one embodiment of the present invention, wherein 1 is a laser beam generator, 2 is
The laser beams generated thereby are shown. Here, it is assumed that the laser beam 2 is bent in a required direction by the reflecting mirror 3, is focused to a required degree by the condenser lens 4, and is irradiated on the laminated film 5. The steady running in the vertical direction provides the required relative movement between the laser beam 2 and the laminated film 5.

In this case, a motor, for example, a DC motor 6 located completely independent of such a laser system is used.
Is provided so that its axis is substantially parallel to the laser beam 2, and a rotating disk 7 whose contour is located away from the laser beam 2 is fixed to the output shaft of the DC motor 6. 7, a required number of light shielding plates 8 having a contour shape as required and protruding radially outward from the outer edge of the rotating disk 7 can be detachably attached, more preferably, in addition to the rotating disk 7. It is mounted so that its position can be changed in the radial and circumferential directions.

In such a configuration, DC
By rotating the rotating disk 7 by the operation of the motor 6, each of the light shielding plates 8, which are three light shielding plates in the figure, protruding greatly from the rotating disk 7, changes the laser beam 2 to the rotation speed of the rotating disk 7. The reflecting mirror 3 and thus the laminated film 5 are cut off at appropriate time intervals for a time corresponding to the contour shape of the film itself.

For this reason, at least one of the layers of the laminated film 5 that is steadily running is melted by the laser beam 2 reaching the laminated film 5, and the laser beam 2 is cut off. As a result, the tear line 9 in which the non-fused portions 9b are alternately arranged in a broken line is formed. The tear line 9 enables easy opening of the packaging bag under the action of a sufficiently small tearing force when taking out an object to be packaged in the bag-making state of the laminated film 5, and also enables tearing of the bag. , It is possible to proceed exactly following the tear line 9.

By the way, in the tear line 9 formed in this way, the length of the melted portion 9a and the length of the non-melted portion 9b are steadily driven by the operation of a controller provided separately from the laser system. By increasing or decreasing the relative speed of the rotating disk 7 with respect to the laminated film 5, it can be very easily and accurately changed.

This can also be achieved by appropriately selecting the number of light-shielding plates 8 to be mounted and the width of each light-shielding plate 8. In the case where the shape has a chevron-shaped profile, it can also be achieved by selecting a fixed position in the radial direction with respect to the rotating disk 7.

[0016] Therefore, according to this apparatus, the elderly, such as housewives part-time, even technically inexperienced operator, a change of the molten portion length and melting unit interval, where <br / > it is possible intends accurately line the street that was synchronized.

Further, in this device, for example, by moving the entire device away from the laser beam 2 or changing the mounting position of the light shielding plate 8 to the inside in the radial direction,
By blocking only a part of the laser beam 2 at the tip of the light-shielding plate 8, it is possible to increase or decrease the beam energy reaching the laminated film 5. According to this, as described above, FIG. The tear line 9 formed in a broken line as shown in the cross-sectional view is a tear line 19 in which a deep part 19a and a shallow part 19b are alternately arranged although it is a continuous line as shown in FIG. 2 (b). be able to.

According to such a tear line 19, as described above, the damage of the laminate film 5 still occupies not less than conventional continuous pull tear line, an easy-open the packaging bag, like a dashed line tear line 9, which can be advantageously improved,
It is possible to increase the tolerance of the size of each part of the tear line.

Here, the depth of the shallow portion 19b formed by blocking part of the laser beam 2 is determined by the change in the amount of light shielding based on the selection of the depth of the light shielding plate 8 entering the laser beam 2. In addition to being able to be changed appropriately and easily, the shape of the tip of the light shielding plate 8 may be changed to an arc shape, a tapered arc shape, or a polygon shape as shown in FIG. 3, for example. be able to.

When the depth of the shallow portion 19b is changed by a technician, the light-shielding plate 8 is disposed between the laser beam generator 1 and the reflecting mirror 3. Sometimes, the direction of the laser beam generator 1 is slightly changed, and the light shielding plate 8 is
In this case, the direction can be adjusted by changing the direction of the reflecting mirror 3 and adjusting the beam irradiation amount to the light shielding plate 8.

[0021]

As described above, according to the present invention, it becomes technically unfamiliar with simple operations such as speed control of a tear line forming apparatus provided completely independently of a laser system and / or replacement and position change of a light shielding plate. Worker,
The size of the tear line can be easily and accurately changed without touching the laser system at all. Moreover
In the invention of the above, the tapered rotating light shielding plate is
Only by moving it back and forth,
The length and the interval of the fusion zone should be
It can be adjusted more easily below and the tip of the light shield
Edge can partially block laser beam as required
To adjust the depth of the continuous tear line, especially at the shallow depth.
Can be easily controlled.

[Brief description of the drawings]

FIG. 1 is a schematic perspective view showing an embodiment of the present invention.

FIG. 2 is a sectional view showing a tear line.

FIG. 3 is a diagram showing a contour shape of a tip portion of a light shielding plate.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Laser beam generator 2 Laser beam 3 Reflecting mirror 4 Condensing lens 5 Laminated film 6 DC motor 7 Rotating disk 8 Light shielding plate

Claims (1)

(57) [Claims] An apparatus for forming a molten tear line in a laminated film by relatively moving a laser beam and a laminated film, wherein a laser beam generating means and a laminated film are provided between the laser beam generating means and the laminated film. At least one rotating light shielding plate that is driven to rotate around the axis and intermittently blocks part or all of the laser beam is provided .
With a tapered shape, and can move forward and backward
And it was formed by tear lines forming apparatus to laminate the film.