JP2003276919A - Slitter edge inspection device and method for paper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem of frequent malfunction such as detecting small pin holes which need not be eliminated in detecting breakage or cracking at a slitter edge by a transmission light type sensor since paper breakage is easy to occur starting from the cracking at the edge cut by a slitter formed when a reel of paper manufactured by a paper machine into small rollers in printing it to be newspaper or the like. <P>SOLUTION: Two transmission light type sensors are installed on the slitter edge, so that the cracking and the pin holes are discriminated from each other. Malfunction of the sensors is eliminated, and work efficiency in rewinding is improved. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for detecting a defect of a paper edge of a small take-up in a winder process of cutting a paper take-up manufactured by a paper machine in a paper mill into a small take-up. Is.

[0002]

2. Description of the Related Art In a paper manufacturing factory, pulp, which is a raw material for paper, is applied to a paper machine to produce paper. In the paper machine, in order to improve productivity, the paper width and the winding length have been increased while increasing the paper making speed of the paper machine. Recently, the paper width is 10
There are up to m. On the other hand, the demanding newspaper companies, printing companies, and packaging material companies do not own the machinery for handling such wide and large diameter winding. Also, when transporting paper from a paper mill to these consumers, such wide items are difficult to handle.

Therefore, in a paper mill, a full-width large-diameter take-up wound by a machine reel is processed into a take-up having an appropriate width and diameter according to the machine capacity of a printing machine or the like owned by a customer. It is cut into small pieces of a given size before shipping. At a paper manufacturing plant, wide paper fed from a paper machine is once continuously wound on a reel spool with a reel. The winding paper wound on the reel spool is wound on a slitter and divided into small widths as shown in FIG. 2 in order to finish winding into a small width and small diameter (hereinafter, also referred to as small winding) or a flat sheet. . After splitting, if finished in flat format, the length is determined with a rotary cutter and piled up on a pallet in the shape of a flatboy in layboy.

Papers intended for mass printing applications, such as newsprint, are shipped in the form of rolls.
As shown in FIG. 2, after being divided into small widths with a slitter by a winder, the paper is wound around a narrow paper tube. This process is generally called a winder process. The winding wound by the winder is further unwound by the unwinder, the defective portion is removed by inspection, and it is rewound on the paper tube and shipped to the consumer. For a user who prints a large amount within a fixed time, such as a newspaper company, it is necessary to fully operate the printing machine without stopping it. For this reason, the paper manufacturing company removes the defective quality part inherent in the small winding and ships it.

One of the quality defects is a slitter edge defect shown in FIG. 3, which is caused by slitting. Such defects have a maximum length of 1 as indicated by reference numeral 6.
In many cases, foreign matter such as wood chips of about 0 mm is mixed in the paper. Especially for newsprint, thermomechanical pulp is often used as a raw material, and this pulp contains a large amount of wood chips called shives. Since the foreign matter cannot be completely cut by the cutter of the slitter, a part of the paper is cut off or cut as shown in the right side 5 of FIG.

The following problems occur when the small take-up roll including the part where the edge is partially cut as shown in FIGS. 3 and 4 is used for printing. That is, as described above, when a piece of paper whose edges have been cut off or cut is passed through a printing press and tension is applied, the tear spreads from that part as a starting point and induces paper breakage in the printing press. . Therefore, in a paper manufacturing company, the slitting and winding paper is rewound and inspected, the defective portion is removed, and the paper is wound into a predetermined length while being connected by a tape or the like and shipped. As a device for inspecting the edge, a transmitted light type sensor (hereinafter also simply referred to as a sensor) near the edge
There is known a device which is installed to detect an edge defect.

This device comprises a light projecting section containing a light source for emitting infrared rays, laser beams, etc., and a light receiving section for sensing the light beam emitted from the light projecting section, and a paper sheet is provided between the light projecting section and the light receiving section. It is installed so that it runs near the edge. When a normal defect-free edge cut in a straight line passes between the light projecting unit and the light receiving unit, the light beam emitted from the light projecting unit is blocked by the paper and does not reach the light receiving unit. If a part of the edge is missing or has a crack as shown in 4, a part of the light beam emitted from the light projecting portion reaches the light receiving portion, and the defect of the edge is detected.

[0008]

However, when the above-mentioned transmitted light type sensor is actually used, there is a problem that malfunctions frequently occur to detect even normal edges. When the cause of the malfunction of the transmitted light type sensor was investigated, it was found that the sensor detected a pinhole as small as about 0.5 to 1 mm as shown in FIG. Adjusting the sensor to make it less sensitive can reduce malfunctions, but increased the missed detection of defects caused by foreign particles. On the contrary, if you increase the sensitivity to reduce the number of missed detections,
This time, there were many malfunctions to detect pinholes. As described above, it was found that it is extremely difficult to eliminate malfunction and prevent detection omission.

[0009]

As a result of earnest studies on the countermeasure for the above malfunction, the inventor was able to prevent the malfunction by the means described below. That is, in the process of cutting the reel-wound paper made by a paper machine into a predetermined width with a slitter and winding it into a small roll, the first transmitted light whose detection range is near the slitter edge cut by the slitter. Type sensor and a second transmitted light type sensor having a detection range inside the first transmitted light type sensor are disposed in close proximity to each other, and a detection range of the first transmitted light type sensor and Since the transmitted light type sensor No. 2 is installed so that the detection ranges do not overlap, the slitter edge defect is detected and determined.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In a process of cutting a reel-wound paper made by a paper machine shown in FIG. 2 into a predetermined width by a slitter and winding it by a winder, a slitter edge cut by the slitter as shown in FIG. As shown in FIG. 1, a first transmitted light type sensor having a detection range in the vicinity of the above and a second transmitted light type sensor having a detection range just inside the detection range of the first transmitted light type sensor are installed. To do.

The present invention will be described in detail below with reference to the drawings. In FIG. 4, P is a pinhole, Q1 and Q2 are the detection ranges of the sensors, and the shaded areas indicate the detection ranges on the paper surface of the respective sensors. As is clear from FIG. 4, the defective portion with the edge being torn or torn is detected by both the sensors Q1 and Q2. On the other hand, since there is a high probability that the pinhole P is detected only in one of Q1 and Q2, the one detected by both sensors is determined to be an edge defect. In this case, depending on the shape of the defective portion, both sensors may not always be able to detect at the same time, so it is desirable to be able to determine a defect even if there is a certain time lag in detection. Then, the object of the present invention can be achieved by removing the defective portion while unwinding with an unwinder, and winding it to a predetermined diameter while connecting the paper before and after the removed portion.

Most pinholes are much smaller than edge defects that cause paper breaks, and the cause of the pinholes is not due to the slitter. Therefore, the place of occurrence is not limited to the vicinity of the edges. . The purpose of the present invention is mainly to prevent paper breakage at the time of printing, but since the size of the defective portion differs depending on the thickness and strength of the paper, it is a prerequisite that the smallest defect regarded as a defect can be detected. , Q
Use the detection range of 1 or Q2 as small as possible,
It is desirable to set the middle part between the detection ranges of both sensors as narrow as possible. Also, since the shape of the defective portion varies, it is not necessary for both sensors to be aligned right beside the paper flow direction, and they may be offset to some extent, but if they are offset too much, the detection accuracy will deteriorate. , The position is set appropriately. The sensors Q1 and Q2 normally have the same standard, but may have different standards.

The pinholes are generated due to bubbles contained in the pulp raw material, and the maximum size thereof is about 0.5 to 1.0 mm in diameter. Edge defects are traces of foreign matter such as wood chips, and the size of this foreign matter depends on how much foreign matter is removed in the dust removal process of the raw material pulp used, so it cannot be generally stated. The maximum length is about 10 mm. Therefore, the size of the edge defect is much larger than that of the pinhole.

Preferred conditions for the installation position of the sensor, the size of the sensor inspection range, and the positional relationship between the two sensors will be described below. It is necessary to set so that both the sensors in the inspection ranges Q1 and Q2 detect an edge defect and the pinhole is detected in either Q1 or Q2. When processing reel winding into small winding with a winder,
Paper sheets cut with a slitter blade meander slightly. Due to this meandering, if there is any area where the paper sheet does not exist in the inspection range Q1, the sensor will erroneously detect it as an edge defect. In order to avoid this, consider the meandering amount of the paper sheet and set Q1 slightly inside the paper edge.
And have to. 0.5mm to 1mm from the edge
It is preferable to set the inspection range from the inside. The diameters of the inspection ranges Q1 and Q2 are preferably 3 to 6 mm.
Therefore, the center of Q1 is 2.0-4.0m inside from the edge.
It is the position of m. It is preferable that the inspection range Q2 is located immediately inside the Q1 in contact with it.

When the position of the pinhole is at the boundary between Q1 and Q2, it is detected by both sensors, but the sensor detects infrared rays or laser light and raises the level of the amount of light judged to be an edge defect. Therefore, false detection can be avoided. It is possible that pinholes exist in Q1 and Q2, but this probability is extremely low. Also in this case, similarly to the above, erroneous detection can be avoided by increasing the level of the light amount that is determined to be an edge defect.

Further, since it is impossible to install a large number of sensors because the installation position is also limited, it is not always necessary to install two sensors, and three or more sensors can be installed. For example, if three sensors are installed, Q2 inside Q2
3 will be provided, but in this case 2 of Q1 and Q2
Since the inspection range covered by one sensor will be inspected by three sensors, the inspection range of each sensor will be narrowed accordingly. Specifically, it is desirable that the diameters of the inspection ranges Q1, Q2, and Q3 be 2 to 4 mm. And in this case Q1 and Q2 or Q1, Q2 and Q
When the sensor detects in the inspection range of 3, the defect is determined.

[0017]

By using the apparatus of the present invention, when inspecting the edge in the winder process, the edge defect and the cracked portion, which are defects in the quality of the paper, are reliably detected and judged, and are not regarded as defects. Prevents sensor malfunction due to small pinholes.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of an apparatus of the present invention.

FIG. 2 is an explanatory view of the device of the present invention.

FIG. 3 is an explanatory diagram of a defective portion of an edge.

FIG. 4 is an explanatory diagram of a detection range of a sensor

[Explanation of symbols]

1 Projector 2 Light receiving part 3 Edge of paper 4 Slitter edge 5 Edge defect 6 Foreign matter such as wood chips 11 reel winding 12 slitter blades 13 Winder small winding 14 winder drum 15 rider roll P pinhole Detection range of Q1 sensor Detection range of Q2 sensor

Claims (4)

[Claims] 1. In the step of cutting reel-wound paper made by a paper machine into a predetermined width with a slitter and winding it into a small roll, a detection range is in the vicinity of a slitter edge cut by the slitter. Of the first transmitted light type sensor and a second transmitted light type sensor whose detection range is inside the detection range of the first transmitted light type sensor are installed close to each other, and detection of the first transmitted light type sensor is performed. A slitter edge defect detection and determination device, which is installed so that the range and the detection range of the second transmitted light type sensor do not overlap. 2. The apparatus according to claim 1, wherein the paper portion detected by both the first and second transmitted light type sensors is determined as a defective portion of the edge of the paper. A method for detecting and determining defects. 3. The device according to claim 1, wherein the device has at least three transmitted light type sensors. 4. The apparatus according to claim 3, wherein a paper portion detected by a plurality of transmitted light type sensors among at least three transmitted light type sensors is determined as a defective portion of an edge of the paper. Detects slitter edge defects,
How to judge.