JP6538740B2 - Film winding machine and film winding method - Google Patents

Description

  The present invention relates to a film winding machine and a film winding method, and more particularly to a mechanism for switching a film winding core in a turret film winding machine.

  The film formed in the production line is taken up by a film winding machine installed downstream. In order to increase the film production efficiency, it is desirable to automatically switch the film wound core to an empty core. Patent Documents 1 and 2 disclose a mechanism for switching the core by pivoting a pair of arms around a pivot axis. Such a mechanism is called a turret system. When switching the core, the film is cut and the downstream end of the film is attached to the empty core. Since the core can be switched while continuing the transport of the film, the production efficiency of the film can be enhanced. Patent Documents 2 and 3 disclose a gas injection mechanism that blows air to a film at a position immediately after being wound around a core. This prevents the air entrained in the film from being caught in the film immediately after being taken up.

JP 2008-230723 A JP, 2013-129540, A JP, 2009-280384, A

  The turret type film winding machine described in Patent Literatures 1 and 2 can switch the core while continuing the transport of the film. However, since a double-sided pressure-sensitive adhesive tape or the like is used to attach the film to the core, a step may be generated on the core, which may cause positional displacement or wrinkles of the film. Although the film winding machine described in Patent Documents 2 and 3 blows air onto the wound film, air is not used when switching the core.

  An object of the present invention is to provide a film winder capable of rewinding a film into an empty core while continuing film transport and suppressing the influence on the film.

The film winding machine of the present invention comprises two rotatable winding shafts on which two cores to which a film to be conveyed is selectively wound are respectively attached, and a film on which the film is wound. On the upstream side of core 1, the core switching mechanism that switches the two cores so that the film is wound around the unwound second core, and the film being transported, located between the two cores It has a cutter for cutting, and a gas injection mechanism located between the cutter and the second core, for blowing a gas at the beginning of the film which is cut by the cutter and wound around the second core. The film forming direction between the cutter and the second core when the film is cut by the cutter and the discharge direction of the gas discharged from the gas jet mechanism make an angle θ of 15 ° ≦ θ ≦ 45 ° It is.

  The gas blown from the gas jet mechanism presses on the core the beginning of the film which is cut with a cutter and wound around the second core. For this reason, it is not necessary to arrange the tape etc. for sticking of a film on a core, and the influence on a film is suppressed. Therefore, according to the present invention, it is possible to provide a film winder capable of rewinding the film into an empty core while continuing the transportation of the film and suppressing the influence on the film.

It is a schematic block diagram of the film winder which concerns on one Embodiment of this invention. It is the elements on larger scale of the film winder shown in FIG. It is a perspective view of a gas injection mechanism. It is a conceptual diagram which shows the method of rewinding to the empty core of a film. It is a conceptual diagram which shows the method of rewinding to the empty core of a film. It is a conceptual diagram which shows the method of rewinding to the empty core of a film. It is a schematic block diagram of the film winder of a comparative example. It is a figure which shows the analysis result of the gas injection mechanism and the airflow in the vicinity of a core. It is a figure which shows the analysis result of a film pressing pressure.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a schematic configuration view of a film winder 1 according to an embodiment of the present invention, and FIG. 2 is a partially enlarged view of the film winder shown in FIG. The film winder 1 is provided downstream of a film production line (not shown), and winds a film formed of polyester, polypropylene or the like.

  The film winding machine 1 includes a base 2, a pair of arms (core switching mechanisms) 3a and 3b rotatably supported by the base 2, and two rolls rotatably attached to the tips of the arms 3a and 3b. And a take-up shaft 4a, 4b. The arms 3a and 3b are rotatable (pivotable) around the rotation axis 15. The cores 5a and 5b on which the film F is wound are detachably mounted on the winding shafts 4a and 4b. The cores 5a and 5b have a cylindrical outer shape, and are formed of cardboard, metal, wood, resin or the like. The winding shafts 4a and 4b can be rotated by motors (not shown) around central axes 4c and 4d. As a result, the cores 5a and 5b can also rotate around the central axes 4c and 4d to wind up the transported film F. The number of winding shafts 4a and 4b is not limited to two, and three or more winding shafts may be provided.

  The film F to be conveyed is always wound only on one of the cores 5a or 5b (winding shaft 4a or 4b), and when the film F of a predetermined length is wound on the core 5a or 5b, the other empty It is switched to the core 5b or 5a (winding shaft 4b or 4a). In the following description, the core on which the film F is wound is referred to as a first core 5a, and the film F is not wound, ie, an empty core is referred to as a second core 5b. The second core 5b is located downstream of the first core 5a with respect to the transport direction T of the film F when the film F is wound up by the first core 5a, and switching of the cores 5a and 5b starts Wait at that position until it is done. When the film F having a predetermined length is wound on the first core 5a and switching of the cores 5a and 5b is started, the second core 5b is a film by the rotation of the arms 3a and 3b serving as the core switching mechanism. The film F is moved upstream of the first core 5a with respect to the transport direction T of F, and the film F is wound around the second core 5b.

  A cutter 6 for cutting the film F being transported is provided between the two cores 5a and 5b. The cutter 6 cuts the film F in the width direction while moving in the width direction of the film F (direction perpendicular to the paper surface in FIG. 1) by a driving device (not shown).

  A gas injection mechanism 7 is provided between the cutter 6 and the second core 5 b located downstream of the first core 5 a with respect to the transport direction T of the film F. The gas injection mechanism 7 sprays a gas on the start end F1 (see FIG. 6A) of the film F which is cut by the cutter 6 and wound around the second core 5b. The type of gas is not particularly limited, but in the present embodiment, air is injected. FIG. 3A shows a perspective view of the gas injection mechanism 7. The gas injection mechanism 7 has a plurality of nozzles 9 provided with circular discharge openings 8 from which air is discharged, and an air supply mechanism 16 for supplying air to the nozzles 9. The nozzles 9 are arranged at equal intervals in the width direction W of the film F. As shown in FIG. 3 (b), the gas injection mechanism 107 according to another embodiment may be provided with a slit 10 extending in the width direction W. It is desirable that the slits 10 extend over the entire width of the film F. The nozzle 9 can inject air at a relatively high speed. The slits 10 can apply a jet of air uniformly to the film F across the width of the film, although the velocity of the injected air is small.

  The cutter 6 and the gas injection mechanism 7 are supported by a pivoting arm 12 attached to a support 11. The pivoting arm 12 can rotate around a rotation axis 13. The touch roll 14 is further attached to the pivoting arm 12. The cutter 6, the gas injection mechanism 7 and the touch roll 14 are used only when switching between the cores 5a and 5b. Therefore, when the film F is wound around the first core 5a (see FIGS. 4 (a) and (b), FIG. 5 (a)), the pivoting arm 12 pivots upward, and the cutter 6 and The gas jet mechanism 7 and the touch roll 14 are retracted to a position where they do not interfere with the film F.

  Next, the method of switching between the cores 5a and 5b will be described with reference to FIGS. Referring to FIG. 4A, the pivoting arm 12 pivots upward, and the film F is continuously and automatically wound around the first core 5a. The first core 5 a is located downstream of the second core 5 b with respect to the transport direction T of the film F. The second core 5b is an empty core. As shown in FIG. 4B, the film F having a predetermined length is wound around the first core 5a. The predetermined length is not limited, but can be selected, for example, in the range of several hundred meters to several thousand meters, depending on the application of the film F and the capability of the manufacturing equipment. Next, the arms 3a and 3b rotate clockwise in FIG. 4 (b), and as shown in FIG. 5 (a), the two cores 5a and 5b are switched. Specifically, the arms 3a and 3b rotate approximately 180 ° to a position where the second core 5b contacts the film F being transported and lifts the film F upward. As a result, the film F is wound around the second core 5b on which the film F is not wound up, on the upstream side of the first core 5a. During this time, the transport of the film F is continued. Next, the pivoting arm 12 is rotated clockwise in FIG. 5 (a), and as shown in FIG. 5 (b), the touch roll 14 is pressed on the film F conveyed on the downstream side of the cutter 6 . Thus, the cutter 6 and the gas injection mechanism 7 are set at predetermined positions with respect to the film F. Next, as shown in FIG. 6A, the cutter 6 operates to cut the film F in the width direction W. At the same time, air is injected from the gas injection mechanism 7, and the film F on the downstream side is wound around the second core 5b from the tip F1 as shown in FIG. 6 (b). After this, the film F to be conveyed is taken up by the second core 5b. The film F and the cores 5a and 5b may be electrostatically applied in advance so that the front end F1 of the film F is reliably held by the second core 5b. The first core 5a on which the film F is wound is removed from the winding shaft 4a, and the new core 5a is mounted on the winding shaft 4a. The pivoting arm 12 pivots counterclockwise to the retracted position. The film winder 1 returns to the state shown in FIG. 4 (a) and then repeats the above operation.

  As described above, in the present embodiment, since the start end F1 of the film F wound by the second core 5b is pressed against the second core 5b by the jet of air, the adhesive tape or the like that causes the step is the film F and the second There is no need to intervene between the core 5b of For this reason, wrinkles and breakage of the film F are less likely to occur. FIG. 7 shows a comparative example in which the cores 5a and 5b are switched using the touch roll 24 instead of the jet of air. In the configuration shown in the figure, the touch roll 24 is pressed against the core 5 b from the downstream side of the core 5 b in the transport direction T of the film F, and the film 5 is nipped by the core 5 b and the touch roll 14. By electrostatically applying the film F and the core 5b in advance, the start end F1 of the film F cut by the cutter 6 is attracted to the core 5b, and the film F is wound around the core 5b. However, in this configuration, the film F may be damaged such as a flaw by the frictional force when passing through the nip portion between the core 5 b and the touch roll 24. In particular, when the transport speed of the film F is 300 m / min or more, the possibility is increased. On the other hand, in the present embodiment, since the film F is pressed against the second core 5b by the jet of air, the possibility of damaging the film F is small.

  When the leading end F1 of the film F is pressed against the second core 5b with a jet of air, it is desirable to make the film pressing pressure of the jet as large as possible and to make it as uniform as possible in the width direction W. For that purpose, an angle θ (see FIG. 2) formed by the transport direction T of the film F between the two cores 5a and 5b and the discharge direction of the air discharged from the gas injection mechanism 7 is important. FIG. 8 (a) shows the velocity distribution of the air flow around the gas injection mechanism 7 and the second core 5b when air is blown from a direction substantially perpendicular to the rotation direction of the second core 5b. (Hereinafter referred to as Example 1). FIG. 8 (b) shows the velocity distribution of the air flow around the gas injection mechanism 7 and the second core 5b when air is jetted from the direction along the rotation direction of the second core 5b (hereinafter, referred to as Example 2). The direction along the rotation direction of the second core 5b may be referred to as the forward direction, and the forward direction is synonymous with 0 ° ≦ θ <90 °. The airflow analysis software "Solidworks simulation 2015" was used to calculate the velocity distribution (hereinafter, "Solidworks simulation 2015" was used in all the analysis).

  In Example 1 shown to Fig.8 (a), a part of jet stream of air flows in the reverse direction to the rotation direction of the 2nd core 5b, and has collided with the film accompanying flow. The film accompanying flow is an air flow carried along the film surface by the frictional force of the film surface and traveling in the same direction as the transport direction T of the film F. However, in the present embodiment, since a part of the jet flows in the forward direction, the effect of pressing the film F against the second core 5b by the jet of air is obtained. On the other hand, in the second embodiment shown in FIG. 8 (b), most of the jet stream of the air flow in the forward direction along the rotation direction of the second core 5b, so no collision with the accompanying film flow occurs. There is no air flow flowing in the direction opposite to the rotation direction of the core 5b of No.2.

  FIG. 9A shows the film holding pressure in the first embodiment, and FIG. 9B shows the film holding pressure in the second embodiment. The vertical axis indicates the film holding pressure at gauge pressure (absolute pressure-atmospheric pressure), and the horizontal axis indicates the dimensionless film width. In any of the examples, a peak of the film pressure is generated immediately below the nozzle 9. In the first embodiment, the film pressing pressure other than immediately below the nozzle 9 is small, and the peak value immediately below the nozzle 9 has a variation of about 15 Pa. This is considered to be because the jet of air was somewhat disturbed by the accompanying film flow. On the other hand, in Example 2, the film pressing pressure at locations other than immediately below the nozzle 9 is generally larger than that of Comparative Example 1, and the peak of the film pressing pressure immediately below the nozzle 9 is substantially uniform. From this, it can be seen that a larger film pressing pressure can be obtained when the speed component in the forward direction is larger. Although illustration is omitted, when the jet of air flows in the direction opposite to the rotation direction of the second core 5b, most of the jet of air flows in the direction opposite to the rotation direction of the second core 5b and collides with the accompanying film flow And the energy of the jet will be greatly reduced. From the above, it is preferable that the angle θ satisfy the condition of at least 0 ° ≦ θ <90 °.

  Table 1 shows the average value in the film width direction W of the film pressing pressure when the angle θ is changed variously. The L / D (described later) was 12. In the case of θ = 120 °, the jet of air flows in the opposite direction to the rotation of the second core 5b, and in the other case, the jet of air flows in the forward direction of the rotation of the second core 5b. It can be seen that when the jet of air flows in the forward direction of the rotation of the second core 5b, the average pressing pressure is improved 2.2 times at the maximum compared to the case of flowing in the reverse direction. Moreover, when the film pressing pressure calculated | required by analysis is 40 Pa or more, in the experiment, generation | occurrence | production of a fold and wrinkles of the film F did not occur, but the film F was able to be wound up favorably. From the above, it is more preferable that the angle θ be 15 ° ≦ θ ≦ 45 °.

  Next, in order to optimize the film holding pressure, it is preferable to set L / D which is the ratio of the distance L between the nozzle 9 and the film F in the discharge direction of air to the diameter D of the discharge opening 8 of the nozzle 9. The scope was examined. The discharge direction of the air is the same as the long axis direction of the nozzle 9. Film hold pressure was calculated by varying L / D. The angle θ was 30 °. Table 2 shows the analysis results of the average film holding pressure when L / D was changed. When L / D is 4 or less, the average film holding pressure decreases. This is because the jet of air jetted from the nozzle 9 interferes with the jet of air colliding with the film F and returning in the direction of the nozzle 9. On the other hand, when L / D is large, the distance L between the nozzle 9 and the film F becomes large, so the average film holding pressure decreases. In order to set the average film holding pressure to 40 Pa or more, it is desirable to set L / D to 6 or more and 10 or less. In addition, it has been found from experiments that it is desirable to set the average pressing pressure to 45 Pa or more when the transport speed of the film F is 500 m / min or more. In this case, L / D is 6 or more and 8 or less. It is desirable to do.

DESCRIPTION OF SYMBOLS 1 film winding machine 3a, 3b arm 4a, 4b winding shaft 5a 1st core 5b 2nd core 6 cutter 7 gas injection mechanism 8 discharge opening 9 nozzle 10 slit 12 rotation arm 14 touch roll F film

Claims (5)

Two rotatable take-up shafts on which are mounted respectively two cores on which the film to be conveyed is selectively taken up;
A core switching mechanism for switching the two cores such that the film is wound around a second core on which the film is not wound on the upstream side of the first core on which the film is wound ,
A cutter located between the two cores and cutting the film being transported;
A gas injection mechanism located between the cutter and the second core, for blowing a gas to the start end of the film which is cut by the cutter and wound around the second core ;
The transport direction of the film between the cutter and the second core when the film is cut by the cutter and the discharge direction of the gas discharged from the gas injection mechanism make an angle θ of 15 A film winder where ° ≦ θ ≦ 45 ° . The gas injection mechanism has a plurality of nozzles arranged in the width direction of the film to discharge the gas, the nozzle has a circular discharge opening, and the diameter D of the discharge opening and the discharge opening The film winder according to claim 1, wherein a relationship of 6 ≦ L / D ≦ 10 holds between the distance L in the discharge direction of the gas to the film transported between the two cores. . The film winder according to claim 2 , wherein a relationship of 6 ≦ L / D ≦ 8 holds between the diameter D and the distance L. 4. The film winder according to claim 1, wherein the gas injection mechanism has a slit extending in the width direction of the film and from which the gas is discharged. Winding the film around the first core while conveying the film and putting the film on the second core upstream of the first core;
Cutting the film being conveyed between the first core and the second core with a cutter;
In between it said cutter second core, have a, and blowing a gas to the starting end of the film that is cut by the cutter is wound the second core,
An angle θ formed by the film transport direction between the cutter and the second core when the film is cut by the cutter and the discharge direction of the gas is 15 ° ≦ θ ≦ 45 ° Some film winding methods.

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