JP3935208B2 - Method and apparatus for measuring the diameter of a roll of web material - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method and apparatus for measuring the diameter of a roll or reel of web material such as paper, tissue paper and the like.
More particularly, the present invention relates to an apparatus suitable for use in a bonding apparatus for bonding the rear end of a reel of web material.
Adhesive devices for these applications are often utilized in paper conversion lines that turn one or more large diameter reels into small rolls of paper such as toilet paper, household absorbent paper, paper towels and the like.
BACKGROUND ART There is a so-called unwinder in this type of conversion line, which is a machine that unwinds a web material on a reel or roll whose diameter is equal to the diameter of the finished product. The finished roll is released from the rewinder and sent to the next work station. The next work station is to cut the reel into small rolls of finished size, and to rewind the trailing edge of the wound material to prevent accidental unwinding during the continuous process of packaging. It adheres on the outer surface of the.
Currently, there are a variety of bonding machines for bonding the free ends. For example, U.S. Pat.Nos. 4,026,752, 4,299,642, 4,475,974, 4,963,223, 5,242,525, British Patent Specification No. 1,326,043, No. 2,073,719, European Patent Specification No. 0 481 929, and International Publications WO-A-9515902 and WO-A-9515903. Many other types of gluing machines have been designed and patented, and the machines described above are just a few examples of gluing machines to which the present invention can be attached, as described below.
In all currently known conventional devices, the rear end of the web material is unwound by various systems and then gradually rewound by rotating the reel in the winding direction over a pair of support cylinders, etc. Thus, in order to position the free end at a predetermined position detected by the sensor, a release and arrangement station for the rear end is used. When the free end is positioned in the correct position, an adhesive is applied to the web material and the free end is rewound. The application of the adhesive can be done at the same bonding station or at subsequent stations that transport the reel by any means without losing the reference associated with the position of the trailing edge. Adhesive is applied to the unrolled end, or to the rolled material, but any part of the adhesive can be attached to any bonding machine with a free end positioning system. The purpose of the invention is the same.
One of the key aspects of the process of converting large diameter reels into small rolls for packaging and sales was formed by small rolls (and unwinders to prevent problems during packaging) The fact that the diameter of the reels must be kept within a certain tolerance. This achievement is often difficult. This is because the thickness of the web material wound on a large diameter reel is not constant and is often variable (although this is not known in the past), this is not only from reel to reel, but also the paper used. This is due to the fact that the outer value may be large and the inner value may be small, even on the same reel, depending on the thickness of the paper because it is pressed in the inner diameter direction. If the parameters given during rewinding are fixed values (paper length and tension, pressure applied by the movable take-up roll, etc.), the diameter of the reel produced by the rewinding machine will change and cause tolerances. Get out of range.
Therefore, it is desirable to read the diameter of the reel during manufacture in order to take quick adjustments to the winding parameters, thereby preventing the actual diameter of the reel from significantly differing from the theoretical reference diameter. U.S. Pat. No. 5,267,703 discloses an example of a rewinder and an example of a winding means with adjustable winding parameters. This is based on measuring the diameter with suitable sensor means when the reel is still in the rewinder.
Objects of the invention The object of the present invention is to adjust the winding parameters where necessary and to modify the winding parameters so as to keep the diameter within a tolerance range, e.g. a reel manufactured by a rewinding machine. It is to provide a new system for reading the diameter of the.
Another object of the present invention is to propose a diameter reading method and apparatus that can be used in a bonding machine in a paper processing line.
Yet another object of the present invention is to provide a diameter control method and apparatus that can be readily employed in existing equipment with little or no technical improvement.
Further objects and advantages of the present invention will become apparent to those skilled in the art upon reading the following description of this specification.
Disclosure of the invention The present invention essentially consists of rotating the reel or roll diameter of the wound web material, and also passing a predetermined point of the web material through a predetermined position. Measure by detecting the moment at least twice. The diameter of the reel is obtained from parameters related to the rotation of the reel in the interval between the two predetermined positions.
Indeed, in one embodiment of the present invention, the reel can be placed on a rotating means, which is for example a pair of rolls, which rotate the reel to give a predetermined on the web material. A detecting means is provided for detecting the amount by which the rotating means moves between two time intervals when the point passes a predetermined position. The reel diameter is determined from this amount of movement.
When reel rotation is caused by means of a single roll or pair of rolls, the detected motion is represented by the angle of rotation of the roll. Assuming that there is no misalignment between the reel and the roll, it was swept (rapidly scanned) by the roll in the time interval that elapses between the first and second passes of a given point on the web material that passes a given position The angle of rotation is used to calculate the circumference of the reel and its diameter.
In another embodiment, the present invention provides winding by rotating the reel at a conventional speed and detecting when a predetermined point on the web material passes a predetermined position at least twice. Measuring the diameter of the reel or roll of web material taken. By measuring the time elapsed between the two passes, the reel diameter can be calculated from the speed and the time value.
Theoretically, this method can be applied at any point in the process of manufacturing a reel of web material or even outside the manufacturing process, for example by taking a plurality of samples and measuring them. If the measurements are made in-line, the measured readings can be advantageously used to prevent deviations from a predetermined tolerance range in order to modify the winding parameters.
The general method is particularly beneficial in the paper conversion described above. For this purpose, it is beneficial to apply the method of the invention in an already existing stage of the conversion process, i.e. in positioning the trailing edge of the web material before bonding. In this use the method is
a) opening the rear end of the web material wound on the reel;
b) continuing to rotate the reel in an appropriate direction for winding the web material and detecting the moment when the point on the web material (typically the trailing edge) passes through the predetermined position;
c) operation while measuring parameters relating to the movement of the reel, such as the time that elapses between the first and second passes when the point passes the position, or the amount of movement of the reel rotation means (a) And a step of repeating (b),
d) A step of calculating the diameter of the reel from the parameters relating to the rotation operation of the reel is provided.
In this format, the diameter measurement is very short in the amount of time associated with the second action of opening and detecting the end of the paper, i.e., the amount of time required to make a complete revolution of the reel. Furthermore, by performing the check only on the appropriate reels, not on all the reels, the time required to position the free end twice before bonding is reduced. If this method is intended to use the readings provided on the gluing machine to automatically adjust the winding parameters, the machine control program can be modified and, if necessary, rewinded. If the machine control program is modified, it can be used for existing bonding machines. A major advantage of the method of the present invention is that it can be performed very inexpensively and does not require mechanical modifications to existing lines.
The invention also relates to an apparatus for carrying out the method described above. This device
-Means for rotating the reel in the winding direction;
-Sensor means for detecting the moment when a point on the web material passes a predetermined position;
Elapse from a parameter relating to the rotation of the reel, for example from the movement of the reel rotation means, or from the value of the rotation speed of the reel, or between two successive passes in which the point passes the predetermined position And control means for calculating the diameter of the reel from time.
In practice, since the measurement is advantageously made by detecting the passage of the rear end of the web material, the apparatus further comprises a solution means for unraveling the end portion of the web material.
For the reasons mentioned above, this device advantageously forms in this case an integral part of the bonding machine for bonding the free ends of the web material, which also has a free end prior to the bonding of the free ends. Position it.
Other advantageous features of the method and apparatus of the present invention are set forth in the appended claims.
[Brief description of the drawings]
The invention will be more clearly understood from the description and the accompanying drawings. The accompanying drawings illustrate substantial and non-limiting examples of the invention.
FIGS. 1 to 7 schematically show seven successive steps of the method according to the invention in one possible embodiment.
FIGS. 8 and 9 show two improved embodiments.
Detailed description of preferred embodiments The method will now be described in conjunction with the process of adhering the trailing end of the web material wound on a reel, although this is the preferred form of the present invention. It should be recognized that the method should not be understood in a limited way. This can be applied to the separation stage before bonding or even to the process where the rear end is not bonded.
Since there are a myriad of bonding machines to which the method of the present invention can be applied, and a detailed description of the various mechanical parts of the bonding machine is not essential to understanding the present invention, only the important components of the machine will be described below. I will explain vaguely. For a more detailed description of machines that can utilize the method of the present invention, see the earlier cited patents or other patents in the same field. Those skilled in the art will understand that, based on the following description, the present invention can be implemented in all bonding machines, or even in simpler machines with only a few of the elements of the bonding machine. I will.
FIG. 1 shows the first stage of the process of bonding the rear end portion Lf of the reel L of the web material N. The reel L is positioned in the correct position and is supported on a pair of cylinders 3, 5 that rotate in the same direction at a conventional speed, preferably at a constant speed. Above the two cylinders 3 and 5, there is arranged a blow nozzle 7 that lifts the free end Lf when the reel L rotates and its end passes the position shown in FIG. As a result, the free end Lf and a portion of the web material N are unwound and fall onto the surface 9 as shown in FIG. Since the surface 9 is the upper wall of the vacuum box 11 and the surface 9 is appropriately perforated, the vacuum in the vacuum box 11 adsorbs the web material N onto the surface 9.
Above the support surface 9 is provided an optical sensor or other suitable type of sensor, schematically shown at 13, which can be positionally adjustable if necessary. This sensor detects the passage of a predetermined point on the surface 9 at the edge of the rear end Lf. More specifically, the sensor 13 transmits a signal at the moment when the free end Lf reaches the position shown in FIG. The two cylinders 3 and 5 are still rotating, whereby the rear end Lf is gradually rewound so that the rear end Lf reaches this position.
Therefore, the description so far corresponds to the normal stage of positioning the rear end portion Lf of the reel L in a conventional type bonding machine. Therefore, in the conventional bonding machine, the positioning stage is finished and the reel proceeds to the bonding stage. On the other hand, in the present invention, the rotation of the cylinders 3 and 5 is continued until the above operation is repeated again. . This is shown in FIG. 4 and FIG.
Since the rotational speed of cylinders 3 and 5 is known, and the peripheral speed V of reel L is also known (according to a reasonable assumption that there is no deviation between reel L and cylinders 3 and 5), sensor 13 By reading the interval of time T between the transmitted signal (simply shown in FIG. 3) and the second signal transmitted by the sensor (simply shown in FIG. 5), The diameter D can be calculated very accurately.
D = V * T / π
A central processing unit 15 (shown for simplicity only in FIG. 5) that receives two successive signals from the sensor 13 and stores the rotational speeds of the cylinders 3, 5 is It is possible to calculate the diameter D before the operation is performed. If the calculated value of the diameter D is outside the tolerance range around the theoretical value Do, the central processing unit 15 is a rewinding machine (or, although not shown, another central processing unit that controls the rewinding machine). A correction signal for correcting the winding parameter is sent to This modification, of course, only affects the reels that follow the measured reel and the reels produced in the meantime, but sufficiently prevents excessive deviations from the theoretical value Do.
Since the calculation of the diameter D needs to double the time required for positioning the rear end Lf, it is preferable that the diameter check is performed not on all reels but on some, for example, every ten reels. . This allows the check time to be substantially reduced and the output from the unwinder upstream of the bonding machine (or the output of multiple bonding devices provided for a single winding device). Can be absorbed without problems. Intermittent checks on several reels, but not on all reels, are sufficient to ensure that the diameter tolerance is maintained with proper modification of the winding parameters.
After measuring the diameter and positioning the rear end Lf, an adhesive is applied. This operation is shown in FIG. 6 in the example described. The adhesive C is applied by a nozzle 17 that moves parallel to the axis of the reel L. The application of the adhesive can be done at the same station where the positioning was made, or at another station, with a moving nozzle (shown in the example), or for example a reel, along the groove where the adhesive is discharged It can be done by other conventional systems such as a method of rotating on the surface or other means. The method of moving the reel to the bonding station for adhesive application, as well as the subsequent closing of the trailing edge, is shown schematically in FIG. 7 but is inappropriate for the purposes of the present invention. .
In another embodiment of the present invention, an encoder 17 connected to either of the two rolls 3 and 5 (for simplicity, the case of connection to the roll 5 is shown only in FIG. 5) The angle at which the roll 5 rotates in the time interval that elapses between the first and second readings is detected. Given the diameter of roll 5 and assuming that there is no misalignment between reel L and roll 5 (for example, roll 5 is coated with a high coefficient of friction), the angle detected by encoder 17 can be calculated using the following equation: It can be used to obtain the diameter D of the roll L.
D = αR / π
In this equation, R is the radius of the roll 5, and α is the angle detected by the encoder 17, expressed in radians. The value αR substantially represents the integral of the peripheral speed of the roll 5 in the time interval between two moments when the rear end Lf passes in front of the sensor 13.
In the embodiment shown in FIG. 8, the reel rotating means consists of a single drive roll 5 and an inclined support plate 6 having a low coefficient of friction, for example coated with a suitable synthetic resin. The encoder 17 is connected to the drive roll 5 and detects the rotation angle α of the roll. Signals transmitted from the encoder 17 and the sensor 13 are sent to the central processing unit. This operation is the same as described above. Even without the angle encoder 17, the rotation angle can be measured by a time and speed based measurement technique similar to the technique described above.
FIG. 9 shows an embodiment in which the reel L is rotated by the belt 8 that runs around the two pulleys 23 and 25. Although the reel L is pressed onto the belt 21 and the play roll 4, the play roll 4 may be a support surface similar to the surface 6 in FIG. The central processing unit 15 receives a signal representing movement or speed generated by an encoder and obtained from one of the pulleys 23, 25 around which the belt 21 travels. Conversely, the signal can also be obtained from a sensor 27 that reads a series of equidistant reference marks 21A on one surface of the belt 21 or other appropriate reference to provide information about other belt movements. it can. This material can be used for one of the methods for calculating the diameter of the reel L already described.
The embodiments described herein can be combined in various ways.
The drawings show purely examples given by the method of substantial demonstration of the present invention, so that the invention can be shaped and arranged without departing from the scope of the concepts underlying the present invention. It is possible to change. Any reference sign in the following claims is intended to facilitate reading of the claims with reference to the description and drawings, and is not intended to limit the scope of protection by the claims.

Claims (10)

The diameter of the reel or roll of the wound web material (N) is measured in the step of placing and adhering the rear end (Lf) of the wound web material (N) into the reel (L). A method,
Rotating the reel (L);
Detecting a predetermined point (Lf) on the web material (N) passing through a predetermined position;
Calculating the diameter (D) of the reel (L) from at least one parameter (V, T; α) of the rotation;
In a method comprising:
By placing the reel in contact with the reel rotating means (3, 5 ,; 21) at the periphery, the reel was rotated and the predetermined point (Lf) passed the predetermined position. Until the reel is rotated by the reel rotating means (3, 5; 21) until the reel circumference and the reel diameter (D) are
From the peripheral speed (V) of the reel and the time (T) that the predetermined point (Lf) passes between the first passage and the second passage through the predetermined position ,
Or
From the amount of movement (α) made by the reel rotating means (3, 5, 21) during the two passes,
A method characterized by being calculated. a) opening the rear end of the web material (N) wound on the reel (L);
b) continuing to rotate the reel (L) in an appropriate direction for winding the web material (N), and detecting the moment when the point (Lf) on the web material passes the predetermined position;
c) repeating the operations (a) and (b) while measuring the parameters relating to the rotation of the reel during the first and second passes when the point (Lf) passes through the predetermined position;
d) calculating the diameter (D) of the reel from the parameters;
The method according to claim 1, comprising: 3. Method according to claim 1 or 2, characterized in that the predetermined point in the web material (N) is represented by an edge of the rear end (Lf) of the web material itself. Carrying a series of reels (L) one by one to a device for bonding the rear end (Lf) of each reel (L);
Measuring several diameters, not all of the reels (L) carried one by one,
The method according to any one of claims 1 to 3, wherein: Compare the measured value (D) of the diameter with the reference value (Do) and correct the reel (L) winding parameter if the measured value (D) of the diameter is outside the tolerance range of the reference value (Do) A method according to any one of claims 1 to 4, characterized in that a signal is transmitted. A bonding apparatus programmed to place the reel at a corner position where the rear end of the reel (L) is bonded in order to bond the rear end of the roll or reel of the wound web material. L) rotating means (3, 5; 4; 21) for rotating the reel (L) in the winding direction, the reel rotating means contacting the reel in the periphery, and the outer layer of the web material (N) A sensor means (13) for detecting that the point (Lf) passes through a predetermined position;
By detecting two consecutive passes of the predetermined point (Lf) through the predetermined position, from the peripheral speed of the reel (L) and the time (T) that elapses between the two passes, Alternatively, the reel rotation means (3; 5; 4; 21) calculates the circumference of the reel from the amount of movement (α) to rotate the reel between the two passes, and calculates the diameter of the reel. A control means (15) for calculating the speed and a detecting means provided for determining the peripheral speed or the amount of movement (α). 7. The device according to claim 6, further comprising release means (7) for unwinding the end portion of the web material (N). The reel rotating means (3, 5), the releasing means (7), and the sensor means (13) are connected to a web material (N) for continuous bonding by a dispenser (17) of adhesive (C). 8. The device according to claim 7, characterized in that it constitutes means for arranging the rear end (Lf). The rotating means (3, 5) of the reel (L) includes at least one roll (3) that comes into contact with the reel (L), and the detecting means (17) is configured to pass the point through the predetermined position. The apparatus according to claim 7, wherein a rotation angle that is an amount of movement (α) of the roll is detected while (Lf) passes twice in succession. The rotating means (21) of the reel (L) comprises a ring-shaped flexible member (21), and the detecting means (27) detects the speed or movement of the flexible member. A device according to claim 6.

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