JPS6127860A - Method and apparatus for continuously joining web - Google Patents

Abstract

PURPOSE:To automatically and continuously join together webs during high- speed running by absorbing a difference between the web running speed in a web joining process and the web running speed in a web let-out process to compensate for the shortage of let-out web. CONSTITUTION:In a path for a web let out by a web roll driving device 7, which is extended to a web joining device 9, there is provided a dancer device A (including a dancer roll 3) for absorbing a diference between the web running speed in the web joining device 9 where the web on the path is slackened at the time of joining together webs and the web running speed in the web roll driving device 7. The difference between the web running speed in the web joining process and the web running speed in the web let-out process is absorbed by operation of the dancer device A to compensate for the shortage of let-out web, so that the webs can be joined together continuously and automatically, with the web running speed kept high.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field of the Invention] The present invention provides a method and apparatus for continuous web splicing, and more particularly, a method and apparatus for applying stable tension to the web during continuous automatic web splicing of old and new web rolls. The present invention relates to a continuous web splicing method and apparatus in which a web is continuously spliced so as to prevent the web from being cut.

[Conventional technology]

Prior art related to continuous automatic web splicing methods and devices include Japanese Patent Publication No. 56-20255, Japanese Patent Publication No. 57-'1
928, and the one described in Japanese Utility Model Application Publication No. 59-40248 is known. Furthermore, as a conventional technique related to a web tension control method and apparatus, the one described in Japanese Patent Publication No. 56-344 is known.

[Problem that the invention seeks to solve]

However, among the above-mentioned continuous automatic splicing technologies, those that automatically splice webs without reducing the running speed of the webs are capable of webs with normal tensile strength (for example, liners for corrugated poles), ilms, etc. gauze), but not suitable for webs with extremely low tensile strength (for example, disposable diaper liners or water-conducting paper). This is because during automatic splicing, it usually takes a certain amount of time to start up the new web roll, and as a result, a sudden tensile force is applied to the new web roll after automatic splicing, resulting in extremely low tensile strength. This is because the web cannot withstand such tensile force. Therefore, for webs with extremely low tensile strength, the running speed of the webs is slowed down and spliced, and then the running speed is gradually increased again. In addition, the web tension control technology described above cannot control the tension that acts during splicing for webs with extremely low tensile strength. It was gradually rising.

Therefore, in these conventional techniques, when joining webs with extremely low tensile strength, the webs are intermittently fed into a processing machine, etc., resulting in a loss of working time and a change in the working condition. This resulted in defects, etc., and damage in the processing process sometimes occurred.

[Means for solving problems]

The present invention provides the above-mentioned web splicing device by allowing the web on the path from the new web roll to the web splicing device to be unreeled in a relaxed state until the web unwinding speed from the new web roll reaches a steady state. Insufficient feeding of the web until the web feeding speed of the new web roll reaches a steady state by absorbing the difference between the running speed of the web in the combining device and the web running speed in the web roll driving device that feeds out the new web roll. In this way, the above-mentioned problems in the conventional method that occur during web splicing are solved.

That is, the present invention provides a continuous web system comprising a web joining step of joining a leading end of a new web roll to a joining portion such as the end of an old web roll, and a web unwinding step of unwinding the web from the new web roll. In the joining method,
Between the web joining process and the web feeding process, web tension control is performed to compensate for the insufficient amount of web feeding by absorbing the difference between the web running speed in the web joining process and the web running speed in the web feeding process. The present invention provides a continuous web splicing method characterized by providing a step.

The present invention also provides a web roll drive device for feeding out the web from a new web roll as a device used in the above method;
In a continuous web splicing device that is equipped with a web splicing device that splices the leading end of a new web roll to a splicing section such as a terminal end of an old web roll, the web fed out by the web roll drive device is A dancer is provided on the path leading to the web splicing device for relaxing the web on the path during splicing to absorb the difference between the web traveling speed in the web splicing device and the web traveling speed in the web roll drive device. The present invention provides a continuous web splicing device characterized in that the device is provided with a continuous web splicing device.

〔Example〕

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an embodiment of the continuous web splicing apparatus of the present invention used in the method of the present invention shown in the drawings will be described below.

Fig. 1 is a front view of the main parts of the continuous web splicing device of the present invention, and Fig. 2 is a running speed diagram after the new web roll starts to feed out when replacing the old and new web rolls. The apparatus of this embodiment is adapted to be used for automatic joining of backing paper or water-conducting paper in a disposable diaper processing machine.

In FIG. 1, 1 is a web roll shaft equipped with a web roll 6, and 7 is a web 10 from the web roll 6.
9 is a web splicing device, and the web roll shaft 1 and the web roll drive device 7 are located not only within the left-hand chain double-dashed line area in FIG. However, they are arranged in the same way in the two-dot chain line area on the right. figure).

Thus, the apparatus of the present invention has the above-mentioned left and right web rolls 6.
A dancer device A is provided on each path in which the webs 1010 fed out from the webs 6 reach the web splicing device 9, respectively. The dancer device A
As will be described later, the web traveling speed in the web splicing device 9 is increased by relaxing the newly fed web 10'' or 10 on the path during web splicing;
The above-mentioned devices constituting the apparatus of the present invention in the corresponding web roll drive device 7 will be described in detail (for devices having the same configuration on the left and right sides as described above, the left side will be described in detail). The roll drive device 7 is configured as a device that presses a drive belt 72 with one end as a fulcrum 73 against the outer periphery of the web roll 6 from the outside using an air cylinder 71. At the same time as the web splicing device 9 is activated, the air cylinder '/1 can be activated to rotate the web roll 6 in the direction of the arrow.

The dancer device A also includes a dancer arm 2 that is rotatably provided around the web roll shaft 1;
Dancer rollers 3, 3 rotatably attached to one end of the dancer arm 2, a linear servo motor 4 attached to the other end of the dancer arm 2 for rotating the dancer arm 2, and the dancer roller. 3.3, the potentiometer 5 detects the rotation angle of the dancer arm 2, and the web 1"0" in the web roll drive device 7. The tacho generator 1)'' detects the running speed of the web (the actual speed at which the web 10'' is fed by the web roll drive device 7) and the running speed of the web lO or 10'' in the web splicing device (the web 10 or 10'' from outside the system). By controlling the linear servo motor 4 with a control signal based on a detection signal detected by the tachometer generator 1) that detects the required payout speed of 10 degrees, the web splicing device 9 is actuated and the dancer arm 2 is
The web roll is rotated clockwise from the origin O to absorb the amount of underfeeding that occurs when the web roll begins to be fed out.

The web splicing device 9 also includes a pair of nip rollers 91, 91 . Air cylinders 92, 92 that press the nip rollers 91.91 against each other, motors 93, 93 that drive the nip rollers 91.91 during web splicing, and connections between the motors 93, 93 and the nip rollers 91.91 are turned on and off. The nip rollers 91, 91 are configured as suction rollers to hold the leading end of the web 10' unwound from the left web roll 6, and the nip rollers 91, 91 are configured with a vacuum device (not shown). ).

Next, an embodiment of the continuous web splicing method of the present invention using the above-described continuous web splicing device will be described with reference to the drawings.

In an embodiment of the method of the present invention, first, one foot of the web 10'' wound around the left web roll (hereinafter referred to as new web roll) 6 to be newly unwound is unwound, and then the dancer roller 3 , 3 and a fixed guide roller 8.8 as shown in FIG.
Attach adhesive tape (not shown) to the right side of the tip.

In the preparation state described above, when the right web roll (hereinafter referred to as the old web roll, not shown) runs out or is about to run out, the web splicing device 9 is activated by a detection signal that detects this. A web joining step is carried out, and the leading end of the web 10' is joined to the joining portion such as the end of the web 10 via the adhesive tape. That is, in response to the above detection signal, the right nip roller 91 is pressed against the left nip roller 91 by the air cylinder 92, and at the same time, the left clutch 94 is engaged to match the running speed of the web 10 detected by the tacho generator 1). The left nip roller 91 rotates, and the web joining process is performed. This web joining process is normally completed while the dancer arm 2, which will be described later, is turned from the origin O by an angle θl. That is, when the dancer arm 2 rotates by an angle θ1 from the origin O, the right air cylinder 92
is retracted, releasing the vacuum connected to the left nip roller 91 and simultaneously disengaging the left clutch 94, thereby opening the web splicing device 9. In addition, Web 1
When joining the old web roll 6 of web 10' to the new web roll 6 of web 10' before reaching the terminal end, a signal for performing the web joining process may be input manually. In this case, it is preferable to provide a step of cutting the web 10 unwound from the old web roll after completion of splicing.

At the same time as the above-mentioned web splicing process is started, the web roll drive device 7 is activated to move the web 1 from the new web roll.
A web unwinding step of unwinding 0° is carried out, and the web 10° is gradually unrolled. That is, the already rotating drive heald 72 is pressed against the outer periphery of the new web roll 6 by the air cylinder 71, so that the new web roll 6 rotates in the direction of the arrow, and the web feeding process is performed. The outer peripheral speed of the new web roll 6 in this web feeding process (web 10° from the new web roll 6)
The feed-out speed) V+ usually has a rise characteristic as shown in FIG. 2, and requires rise time until the speed of the web 10 (required feed-out speed from the disposable diaper processing machine) V2 is reached.

Therefore, in order to absorb the insufficient feed amount caused by the speed difference V2-Vl, at the same time as the web joining process is started, the dancer arm 2 is rotated clockwise from the origin 0 by the linear servo motor 4. As a result, the dancer device A, which controls the tension acting on the web 10° and absorbs the underfeeding amount of the web 10°, operates to carry out the web tension control step, and the speed v2 of the web 10 increases. Old and new web rolls are spliced together without slowing down. That is, as shown in FIG.
increases gradually, and reaches the same speed as V2 when T3 hours have passed after the start of web feeding, resulting in a shortage in the web feeding amount. Therefore, the above Vl and (2) are converted to the tacho generator 1). 1)" and by retracting the linear servo motor 4, which is controlled according to the speed difference,
Since the dancer arm 2 is rotated clockwise from the origin O, thereby relaxing the web 10' and absorbing the insufficient amount of the web 10, the rotation angle of the dancer arm 2 shown in FIG. To explain the relationship with the elapsed time shown in the figure, when the new web roll 6 starts to be fed out, the dancer arm 2 is at the origin 0, and there is no elapsed time.

When the web splicing process is completed and the web splicing device 9 is opened, the dancer arm 2 is at a position where it has rotated over θ from the origin, and the elapsed time is T, and at that time the new web roll 6 The outer peripheral speed ■1 is still approximately O. After further time elapses, at time T2, the dancer arm 2 is at a position rotated by 02 from the origin 0. The time at which v, = v2 occurs is T3, and at this time the dancer arm 2 is at a position rotated by θ3 from the origin. At the start of operation of the web roll drive device 7, the drive belt is set at a speed slightly faster than v2, so after T3, Vi > v2, the linear servo motor 4 switches from backward to forward, and the dancer - Arm 2 starts returning towards origin 0. After T4, the speed of the drive belt 72 gradually decreases, and at T5, it is controlled so that Vl = v, and at this point, the speed of the dancer arm 2
is controlled to return to the origin O. In this case, if the speed of the drive heald 72 is increased, the time until T5 can be shortened. After passing T5, the speed becomes approximately 1-v2-driving belt 72, and the web 10' can be fed with the dancer arm 2 fixed at the origin O.

As described above, according to the continuous web splicing method of the present invention, the difference between the web running speed in the web splicing process and the web running speed in the web paying out process is controlled between the web splicing process and the web feeding process. Web tension can be controlled by providing a web tension control step that absorbs and eliminates the amount of web tension that is insufficient to be fed out.

Although an embodiment of the apparatus of the present invention and an embodiment of the method of the present invention implemented using the apparatus have been described above, the present invention is not limited thereto.

For example, the drive belt 7 in the web roll drive device 7
2 may be replaced with a drive roller or the like, and the web roll shaft 1 may be directly driven instead of being brought into pressure contact with the outer periphery of the web roll 6 from the outside.

Further, although it is possible to control the tension of the web to approximately the same extent without the linear servo motor 4 in the dancer device, it is necessary to provide the linear servo motor 4 in order to reduce the tension acting on the web. Particularly desirable. or,
A tacho generator 1) is used as a detector for controlling the linear servo motor 4. 1) Various types of detectors may be used in place of the potentiometer 5, and instead of using the linear servo motor 4 to rotate the dancer arm 2, the fulcrum axis of the dancer arm 2, which is the same as the web roll shaft 1, may be used. A similar function can be obtained by rotating the dancer arm 2 with a servo motor.Furthermore, the fulcrum of the dancer arm 2 does not need to be provided on the center line of the web roll shaft 1.Furthermore, the dancer arm 2 can be rotated. Instead, it may be something that moves in parallel.

Although it goes without saying that the web splicing device 9 is not limited to this embodiment, it is preferable that the web splicing device 9 be a device that can perform continuous automatic splicing without reducing the running speed of the web.

Next, an example of the continuous web splicing method of the present invention will be shown.

Example 1 When the backing paper of a disposable diaper was automatically joined using the apparatus shown in FIG. 1 under the conditions shown in Table 1 below, the automatic joining was carried out continuously and successfully without causing any cutting of the backing paper. did it.

Example 2 Water-conducting paper from a disposable diaper was used in place of the mount in Example 1, and the water-conducting paper was automatically joined using the apparatus shown in FIG. 1 under the conditions shown in Table 1 below. Similarly, automatic splicing could be carried out continuously and satisfactorily without cutting the water-conducting paper.

Table 1 (Effects of the Invention) As mentioned above, the present invention enables continuous automatic splicing of webs with low tensile strength while maintaining the running speed of the web at a high speed. This not only eliminates time loss, but also provides various advantages such as eliminating defects in processed products due to changes in operating conditions.

[Brief explanation of the drawing]

Fig. 1 is a front view of the main parts of the continuous web splicing device of the present invention, and Fig. 2 is a running speed diagram after the new web roll starts to feed out when replacing the old and new web rolls. It shows. A... Dancer device 2... Dancer arm 3... Dancer roll 4... Linear servo motor 6... Web roll 7... Web roll drive device 9... Web splicing device 10.10' ・・・Wep

Claims (3)

[Claims] (1) A continuous web splicing method comprising a web splicing step of splicing the leading end of the new web roll to a splicing portion such as the end of the old web roll, and a web unwinding step of splicing the web from the new web roll. Between the web splicing process and the web feeding process, a web is provided to compensate for the insufficient amount of web feeding by absorbing the difference between the web running speed in the web splicing process and the web running speed in the web feeding process. A continuous web splicing method characterized by providing a tension control process. (2) Continuous web splicing, which is equipped with a web roll drive device that unwinds the web from the new web roll, and a web splicing device that splices the leading end of the new web roll to the spliced portion such as the end of the old web roll. In the apparatus, the web fed out by the web roll drive device is placed on a path leading to the web splicing device, and the web on the path is relaxed during splicing to adjust the web running speed in the web splicing device and the web roll. A continuous web splicing device characterized by being provided with a dancer device that absorbs the difference in web running speed in a drive device. (3) The dancer device includes a dancer arm that is rotatably provided, a dancer roller that is rotatably attached to one end of the dancer arm, and a linear servo motor that is attached to one end of the dancer arm and rotates the dancer arm. A continuous web splicing device according to claim (2).