JP2008154964A - Manufacture process of absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacture process for absorber that highly precisely and easily confirms whether absorbent polymers have been sprayed as planned so that high-quality absorbers can be manufactured economically. <P>SOLUTION: In this manufacture process, an intermittent spray machine 3 intermittently sprays an absorbent polymer 30 on strips of fiber aggregates 2 under being transported, and after the spray of the absorbent polymer 30, the fiber aggregates 2 (specifically, continuous absorbent bodies 10A) are intermittently cut with a cutter 6 to obtain absorbent bodies 10. Numerical values output from a sensor 74 arranged on the transport route of polymer-sprayed fiber aggregates and giving signals in proportion to the sprayed polymer density in them are recorded. The volume of the absorbent polymer 30 present in each polymer spray region 3a is determined by recording and aggregating the numerical values output from the sensor 74 while each polymer spray region 3a is passing the position of the sensor 74. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an absorbent body preferably used as an absorbent body for absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads.

As absorbent bodies for absorbent articles such as disposable diapers, sanitary napkins, and incontinence pads, absorbent bodies containing fiber assemblies made of fiber materials such as pulp fibers and water-absorbing polymers are widely used.
In the manufacturing process of such an absorbent body, the water-absorbing polymer is intermittently sprayed onto the continuously transported fiber aggregate, and the polymer is not sprayed after the fiber aggregate is covered with the core wrap sheet. Cutting at a part is widely performed (see Patent Documents 1 and 2).
In addition, when the water-absorbing polymer is intermittently sprayed, the water-absorbing polymer is sprayed non-uniformly (see Patent Documents 3 and 4).

JP-A-8-215629 JP 2002-178429 A JP 2004-65929 A JP 2002-272882 A

  However, when intermittently spraying a water-absorbing polymer so that a polymer spraying region in which the water-absorbing polymer is unevenly distributed in the flow direction is formed, it is determined whether or not the polymer is sprayed as designed. It was difficult to confirm the accuracy.

Therefore, the first object of the present invention is to make it possible to easily and accurately confirm whether or not the water-absorbing polymer is sprayed as designed, and to produce a high-quality absorber economically. It is in providing the manufacturing method of.
In addition, the second object of the present invention is to easily determine the quality of the laminated state of the first absorbent layer and the second absorbent layer, and an absorber having a structure in which the first absorbent layer and the second absorbent layer are laminated. It is in providing the manufacturing method of an absorber which can be manufactured with high precision.

  The present invention intermittently sprays a water-absorbing polymer on a belt-shaped fiber assembly to be conveyed by an intermittent spraying device, and intermittently cuts the fiber assembly after the water-absorbing polymer is sprayed by a cutting device. An absorber manufacturing method for obtaining an absorber, wherein an output value of a sensor that outputs a signal proportional to the density of the polymer disposed in the transport path of the fiber assembly after the dispersion of the polymer is recorded, and the absorbent polymer is recorded Absorber that records and integrates the output value of the sensor while the polymer spraying area formed by spraying the sensor passes through the sensor placement position to determine the amount of water-absorbing polymer present in each polymer spraying area The first object is achieved by providing a manufacturing method of the above (hereinafter referred to as the first invention when referred to as the first invention).

  The present invention is a method for manufacturing an absorbent body comprising a laminating step of stacking a discontinuous second absorbent layer on a discontinuous first absorbent layer conveyed at a predetermined interval, wherein the first absorption is performed. The layer and the second absorption layer include a water-absorbing polymer, and include an inspection process for inspecting the laminated state of the first absorption layer and the second absorption layer using a sensor that outputs a signal proportional to the density of the polymer. In the inspection step, the sensor output position during the passage of the laminated body of the first and second absorption layers is recorded, and the sensor output position is recorded. The second object is achieved by providing a manufacturing method of an absorbent body for inspecting the presence and degree of deviation between the first absorbent layer and the second absorbent layer (hereinafter referred to as the second invention). Means this invention)

According to the method for producing an absorbent body of the first invention, it is possible to easily and accurately confirm whether or not the water-absorbing polymer is sprayed as designed, and a high-quality absorbent body can be produced economically. In particular, it is effective when spraying so that a polymer spray region in which the water-absorbing polymer is unevenly distributed is formed intermittently.
According to the method for manufacturing an absorbent body of the second invention, it is possible to easily determine the quality of the laminated state of the first absorbent layer and the second absorbent layer, and the structure in which the first absorbent layer and the second absorbent layer are laminated. The absorber can be manufactured with high accuracy.

The present invention will be described below based on preferred embodiments with reference to the drawings.
In one embodiment of the manufacturing method of the absorbent body of the first invention, as shown in FIG. 1, the water-absorbing polymer 30 is intermittently sprayed by the intermittent spraying device 3 on the belt-shaped fiber assembly 2 to be conveyed, The fiber assembly 2 (specifically, the absorbent continuous body 10A) after the water-absorbing polymer 30 is dispersed is intermittently cut by the cutting device 6 to obtain the absorbent body 10.
In this production method, as shown in FIG. 1, the water-absorbing polymer 30 is divided into polymer spreading regions 3a, 3a,... Formed in the fiber assembly 2 by spreading of the polymer 30 in the respective flow directions. Sprinkle so that it is unevenly distributed. Further, the output value of the capacitance type sensor 74 arranged in the transport path of the fiber assembly after the polymer dispersion is recorded, and the polymer dispersion area 3a passes through the position where the sensor 74 is disposed. The output value of the sensor is recorded and integrated to determine the amount of water-absorbing polymer 30 present in each polymer spray region 3a. In addition, the flow direction of a polymer dispersion | distribution area | region is the same direction as the longitudinal direction of a fiber assembly.

FIG. 1 shows an absorbent body manufacturing apparatus 1 used for carrying out this embodiment.
The absorbent body manufacturing apparatus 1 is continuously transported with a transport mechanism (not shown) of a fiber assembly 2 that continuously transports a belt-shaped fiber assembly that is a dispersion target of the water absorbent polymer, and a water absorbent polymer 30. The intermittent polymer spraying device 3 for intermittently spraying on the fiber assembly 2 and the first core wrap sheet for supplying the first core wrap sheet 21 to the lower surface side of the fiber assembly 2 before the polymer 30 is sprayed A second core wrap sheet 51 is provided on a supply mechanism (not shown) and a surface (hereinafter also referred to as a polymer dispersion surface) on which the water-absorbing polymer 30 is dispersed in the fiber assembly 2 after the polymer 30 is dispersed. The second core wrap sheet supply mechanism 5 to be supplied, and the fiber assembly 2 in which the polymer 30 is dispersed are interposed between the first core wrap sheet 21 and the second core wrap sheet 51. Absorbent continuum 10 A cutting device 6 that intermittently cuts A (see FIG. 3) in the width direction and a control device 7 that controls these operations are provided.

  The transport mechanism of the fiber assembly 2 is formed by appropriately combining known transport elements such as a belt conveyor, a driven roll, and a drive roll, and at least the belt-shaped fiber assembly 2 is dispersed by the polymer intermittent spray device 3. From position 3S, it passes through arrangement position 74S of capacitance type sensor 74 mentioned below, and it is constituted so that it may be conveyed until it reaches position 6S cut by cutting device 6. The transport mechanism of the fiber assembly 2 in the manufacturing apparatus 1 transports the belt-shaped fiber assembly 2 in a state of being placed on the first core wrap sheet 21. Moreover, the conveyance speed of the strip-shaped fiber assembly 2 is constant.

As shown in FIG. 4, the intermittent polymer spraying device 3 includes a polymer supply port 31, a polymer spraying port 32, and a rotor (rotary body) 35 having a polymer retaining recess 34 on the peripheral surface, and the servo motor 39 (see FIG. 1), the rotor is rotationally driven, and the water-absorbing polymer 30 supplied from the supply port 31 to the recess 34 is conveyed to the spraying port 32 by the rotation of the rotor 35 and sprayed from the spraying port 32. It is made like that.
Since the rotor 35 is rotationally driven by the servo motor 39, the rotational speed can be increased or decreased during one rotation. Thereby, the amount of polymer spraying can be increased or decreased while the polymer is sprayed once. A large number of ridges (projections) 34a having a triangular cross section extending in the longitudinal direction of the rotor 35 are formed in the recess 34 for holding the polymer, and movement of the water-absorbing polymer in the recess 34 is restricted.

The polymer intermittent spraying device 3 will be described more specifically.
As shown in FIGS. 1 and 4, the intermittent polymer spraying device 3 includes a cylindrical casing 33 having a polymer supply port 31 and a polymer spray port 32 in the peripheral wall portion and disposed substantially horizontally. A cylindrical rotor 35 having a rectangular shaped recess 34 in plan view on the surface, having the same axis as the casing 33 and being rotatable about the axis, and a supply port 31 in the casing 33. Is moved to the opening 38a by rotation of an internal screw (not shown) and charged into the polymer introduction part 36. The screw feeder 38 is provided.

The casing 33 is supported by a hollow support (not shown) at the back surface, and a rotating shaft (not shown) of the rotor 35 is disposed in the support.
The screws in the rotor 25 and the screw feeder 38 are driven to rotate by servo motors 39 and 40, respectively, and their rotations are controlled by control signals S1 and S2 output from the control device 7. That is, depending on the contents of the input control signals S1, S2, the servo motors 39, 40 start rotation, increase / decrease the rotation speed, maintain the rotation speed constant, stop rotation, etc. To do.

  An opening 35 a that is rectangular in plan view is formed in the peripheral wall portion of the rotor 35, and a part of the water-absorbing polymer 30 (polymer that is not sprayed) supplied through the supply port 31 is placed in the recess 34. It is made to fall through this opening part 35a, without making it hold | maintain. In the rotor 35, a collection hood (collector) 41 that collects the polymer falling from the opening 35a is disposed. Then, when the opening 35a of the rotor 35 reaches the lower side of the supply port 31 of the casing 33, the polymer that is not sprayed falls on the collection hood 41 and is collected.

When the intermittent polymer spraying device 3 is operated, the water-absorbing polymer 30 is introduced into the polymer introduction part 36 by the screw feeder 38, and the water-absorbing polymer 30 passes through the supply port 31 on the outer peripheral surface of the rotor 35 (more specifically, It is supplied into the recess 34).
And the polymer 30 supplied on the outer peripheral surface of the rotor 35 is conveyed to the spraying port 32 by rotation of the rotor 35, and is continuously transported from the spraying port 32 below the spraying port 32. It sprays on the aggregate | assembly 2 with a predetermined spraying pattern (rectangular intermittent spraying). The details of the intermittent polymer spraying device 3 used in this embodiment are described in JP-A-8-215629.

  The second core wrap sheet supply mechanism 5 continuously joins the second core wrap sheet 51 onto the polymer dispersion surface of the fiber assembly 2. The second core wrap sheet 51 to be merged is integrated with the fiber assembly 2 and the first core wrap sheet 21 through an adhesive applied by an adhesive coating machine 52 before the dispersion of the polymer. It becomes the body continuum 10A.

The cutting device 6 is a rotary cutter including a cutter roll 61 having a cutting blade on the peripheral surface and an anvil roll 62 receiving the cutting blade on the peripheral surface.
In the present embodiment, the cutter roll 61 is driven to rotate by a servo motor 63. The anvil roll 62 is configured such that the cutter roll 61 and the shaft are coupled with each other by a gear and rotate in conjunction with the rotation of the cutter roll 61. The anvil roll 62 can have the same circumferential speed as the belt-like fiber assembly 2 or the conveying speed of the absorbent continuous body 10A, or can be increased or decreased. In this embodiment, the anvil roll is a fiber assembly. It is a rotating body that rotates at a speed corresponding to the conveying speed of the body.
The absorber 10 is obtained by cutting the absorber continuous body 10A.

  The control device 7 defines a rotary encoder 71 that outputs a pulse signal for each predetermined rotation amount of the anvil roll 62, a counter 72 that counts the pulse signal output from the encoder 71, and a cutting time by the cutting device 6. And a detection means 73 for detecting a predetermined detection position (such as the position of the cutting blade of the cutter roll) and a polymer spraying position 3S in the transport path of the fiber assembly 2 and disposed in the absorber continuous body 10A. An electrostatic capacitance type sensor 74 whose output value varies according to the amount of polymer contained, and arithmetic processing means 75 for performing various analyzes described later based on measurement data obtained therefrom are provided.

  The encoder 71 is preferably composed of an open collector output type encoder, but can also be composed of a line driver output type encoder. In this case, a pulse converter (conversion to an open collector output format) is interposed between the encoder and the controller.

  The detection means 73 is disposed at a position where the cutter blade of the cutter roll 61 can be detected, detects the closest position of the blade of the cutter roll 61 as the detection position, and outputs an output signal (pulse signal) to the controller 76. Output. The detection means 73 can be composed of a commercially available proximity sensor.

The capacitance type sensor 74 measures the capacitance of an object, and its output value varies according to the amount of the water-absorbing polymer contained in the absorber continuum. The capacitance type sensor 74 used in this embodiment can measure the capacitance of an object passing between sensor gaps, and can measure the density of the object.
In the present embodiment, the capacitance type sensor 74 is between the spray position 3S of the water absorbent polymer and the cutting position of the absorber continuous body 10A in the flow direction (X direction in the figure) of the belt-shaped fiber assembly 21. More specifically, it is arranged between the joining position of the second core wrap sheet 51 and the cutting position of the absorber continuous body 10A. Various known sensors can be used as the capacitance type sensor 74, and for example, “QMS70-O-540” manufactured by Hossbach is preferably used. The capacitance is obtained, for example, by dividing the product of the dielectric constant, the vacuum dielectric constant, and the area by the measurement distance (distance between the sensor and the object).

  The counter 72 is composed of a controller 76, and the arithmetic processing means 75 is composed of a computer 77. The controller 76 is connected to the computer 77 via a cable 86.

  The controller 76 is composed of a multi-channel programmable controller, and as shown in FIG. 5, hardware including a counter 72, a processing device (CPU) 78, a storage device 79, and an internal clock 80, and measurement software And a microcomputer equipped with control software. Measurement software and control software are stored in the storage device 79. In the recording area of the storage device 79, the maximum count number set in accordance with the resolution of the encoder 71, the product length, and the number of encoder pulses is recorded in advance. The controller 76 functions as follows in cooperation with measurement software and hardware.

That is, when a pulse signal is output from the encoder 71 in a state where the measurement software is activated, the controller 76 counts the pulse signal by the counter 72, and the processing device 78 sets the time at the time of counting to the internal clock 80. The count number is recorded in the recording area of the storage device 79 in association with the count time. The processing device 78 resets the counter 72 when the count of the pulse signal by the counter 72 advances and the count reaches the maximum count.
During this time, when a pulse signal is output from the detection means 73, interrupt processing is applied and the interrupt time is read from the internal clock 80 as a disconnect time by the disconnecting device 6, and the counter 72 counts at the interrupt time together with the interrupt time. The number is recorded in the recording area of the storage device 79.
The output value from the sensor 74 is the count number at each count when the intensity (for example, a voltage varying between 0 to 10 V) is read from the internal clock 80 for each pulse counted by the counter 72. And is recorded in the recording area of the storage device 79.
The controller 76 transmits these measurement data recorded in the recording area of the storage device 79 to the computer 77 based on an instruction from the computer 77.

  Further, the controller 76 cooperates with the control software and hardware to convert the signal output from the arithmetic processing means 75 into control signals S1 and S2 that can be input to the servomotors 39 and 40, thereby generating a servomotor. It also functions as a rotation control unit of a servo motor that outputs to 39 and 40.

  The counter 72 only needs to have a processing capability capable of counting the pulse signal from the encoder 71 at high speed. The controller 76 preferably has a high-speed communication function [for example, Ethernet (registered trademark)] in consideration of the subsequent arithmetic processing in the computer 77. The controller 76 can be composed of a commercially available programmable logic controller equipped with a microcomputer.

The computer 77 includes a hardware including a processing device (CPU) 81, a main storage device (RAM) 82, an auxiliary storage device 83, an input device 84 and an output device 85, basic software, and a controller operating on the basic software. The computer system includes data collection software for collecting the measurement data from 76, and software including analysis software for performing various analyzes described later using the measurement data collected by the data collection software. The software is recorded in a recording area of the main storage device 82 or the auxiliary storage device 83.
The computer 77 may be incorporated in a graphic panel.

The manufacturing method of this embodiment is implemented as follows, for example.
First, the control device 7 is activated and a shift cam pattern is selected. The speed change cam pattern is for rotating the rotor 35 of the polymer intermittent spraying device 3 at a non-constant speed in a predetermined pattern. The speed change cam pattern is input by selecting some speed change cam pattern data and software for selecting the speed change cam pattern in the control software described above, and selecting from among the options presented by the software. To do.
FIG. 6 is a diagram showing several examples of the shift cam pattern. In each of the drawings, a is a fluctuation pattern of the rotation speed of the servo motor 39 corresponding to the shift cam pattern, and b is a polymer corresponding to the shift cam pattern. This is a variation pattern of the spread rate. In each drawing, the number of rotations of one absorber and the change over time of the polymer spray amount are shown.
6 (a) is a pattern in which a large amount of water-absorbing polymer is unevenly distributed at the center in the flow direction of each polymer spray region 3a, as shown in FIG. The pattern shown in FIG. 6 (c) is a pattern in which a large amount of water-absorbing polymer is unevenly distributed at a site near the front end or rear end in the flow direction of each polymer spray region 3a.

Then, the operation of the line is started.
Specifically, the conveyance mechanism (not shown) of the fiber assembly 2, the polymer intermittent spraying device 3, the first and second core wrap sheet supply mechanisms, the cutting device 6 and the like are operated.
By the operation of the intermittent polymer spraying device 3, the water-absorbing polymer 30 is sprayed on the fiber assembly 2 that is continuously conveyed in a pattern corresponding to the selected shift cam pattern. The fiber assembly 2 on which the polymer is dispersed is sandwiched between the first and second core wrap sheets 21 and 51 to form the absorber continuous body 10A, and the capacitance sensor placement position 74S is set. And then cut by the cutting device 6.

In this manner, while the absorber 10 is continuously manufactured, the control device 7 performs the following control mainly by the hardware and software of the controller 76.
First, the control device 7 detects the position of the polymer spray region and the cutting position of the fiber assembly, and obtains a deviation between them.
As shown in FIG. 7, the controller 76 records the output value from the capacitance type sensor for each individual pulse (each count), and the predetermined reference position of each polymer spray region is the sensor's output. The passing time at which the arrangement position passes is obtained.
For example, the time when the output value from the capacitance type sensor exceeds a predetermined value is obtained as the time when the tip of the polymer spray area passes the sensor placement site, or the output value from the capacitance type sensor is The time when the value falls below the predetermined value is determined as the time when the rear end of the polymer spray region passes through the sensor placement site. The predetermined value to be compared with the output value from the sensor is set to be slightly higher than the output value while the region where the polymer is not dispersed passes through the site where the sensor is disposed. Alternatively, the output value while the region where the polymer is not dispersed passes through the sensor placement site may be recorded as the output value from the capacitive sensor.

FIG. 7 is a graph showing the change over time of the output value d of the capacitance type sensor together with the pulse signal c obtained by the encoder, and T1 indicates that the tip of the polymer spray region has passed the sensor placement site. This is the time, and T2 is the time when the rear end of the polymer spray region has passed the sensor placement site.
Moreover, the controller 76 calculates | requires the time when the pulse signal from the detection means attached to the cutting device was input using the said measurement data as the cutting time T3 of a fiber assembly.
Then, the controller 76 determines the position of each polymer spray region and the cutting of the fiber assembly from the difference e in the number of counts of the pulse signal P1 corresponding to the passage time T1 and / or T2 and the pulse signal P3 corresponding to the cutting time T3. Find the deviation from the position. Specifically, the difference between the count number recorded as the passage time and the count number recorded as the cutting time is converted from the resolution of the encoder 71 to the length, and this is converted into the position of each polymer spray region and the fiber assembly. This is a deviation from the cutting position.
According to the present embodiment, in this way, the deviation between the position of each polymer spray region and the cutting position of the fiber assembly is not affected by the unevenness of the surface of the fiber assembly or the absorber continuous body. High accuracy and simple confirmation.

  When the deviation amount is out of a predetermined range, the controller 76 sends control signals S1 and S2 for correcting the rotation speed of the servo motor so that the deviation amount falls within the predetermined range. Output for.

Moreover, the control apparatus 7 calculates | requires the quantity of the water absorbing polymer which exists in each polymer dispersion | distribution area | region 3a. Specifically, as shown in FIG. 8, the output value d from the sensor while the polymer spraying region 3a passes through the arrangement position of the capacitive sensor 74 (between P1 and P2). Use the record. That is, the output value d of the sensor corresponding to each pulse is integrated to determine the amount of water-absorbing polymer present in each polymer spray region. The amount of the water-absorbing polymer may not be an absolute amount, but an actual polymer amount (basis weight) or the like can be obtained by collating with results of a plurality of standards whose polymer amounts are known.
When the polymer amount thus obtained is out of the predetermined range set in advance, the absorber including the corresponding polymer spraying area is excluded by a known sorting means from the conveyance path for conveying other normal absorbers. However, it is preferable to send only a normal absorbent body to the absorbent article production line or the like.

The computer 77 takes in the measurement data transmitted from the controller 76, records it in the recording area of the main storage device 82 or the auxiliary storage device 83, and collects the measurement data. In this embodiment, the change in the amount of the water-absorbing polymer in each polymer spray area determined as described above was recorded, and based on the record, the tendency of fluctuation in the polymer amount for a large number of polymer spray areas was determined. . The tendency of the fluctuation of the polymer is displayed by the display means as a graph as shown in FIG. 9, for example. FIG. 9 is a graph showing changes in the polymer amount, where the horizontal axis represents time and the vertical axis represents the polymer amount in the polymer spraying region. And when the curve f which shows the fluctuation | variation of a polymer amount goes upwards, it judges that the polymer amount sprayed by an intermittent spraying device tends to increase gradually, and decreases the polymer amount supplied to the intermittent spraying device 3 Let Specifically, the control device 7 outputs a control signal S2 for reducing the rotation speed to the servo motor 40 that rotates the screw of the screw feeder. On the other hand, when the curve indicating the polymer amount goes downward, it is determined that the amount of polymer sprayed by the intermittent spraying device tends to gradually decrease, and the amount of polymer supplied to the intermittent spraying device 3 is increased. Specifically, the control device 7 outputs a control signal S2 for increasing the rotation speed to the servo motor 40.
By performing such control, it is possible to prevent the amount of the polymer from deviating from the predetermined range H set in advance.

  In this embodiment, from the recording of the output value of the capacitance type sensor, the distribution pattern of the water-absorbing polymer in each polymer spray region is obtained, and when the obtained distribution pattern is different from the preset distribution pattern, The spray pattern of the intermittent spray device is changed so as to approach a preset distribution pattern. Specifically, as shown in FIG. 7 and FIG. 8, the change over time of the output value of the sensor 74 is graphed, and the characteristic value of the graph is compared with the characteristic value of the preset distribution pattern. Then, it is determined whether or not both match. As a characteristic value, a difference between a time T4 when the output value of the capacitance type sensor reaches a peak and a time T1 and T2 when the predetermined reference position of the above-described polymer spraying region passes the sensor arrangement position, etc. Is mentioned. For example, the ratio of the difference in the number of counts between P4 and P1 in FIG. 7 to the difference in the number of counts between P2 and P1 can be used as a characteristic value. For example, if the difference between the ratios is within a predetermined value, it is determined that the difference is the same, and if the difference is greater than or equal to the predetermined value, the speed of the servo motor 39 is increased or decreased so that the ratio approaches.

  According to this embodiment, even when the water-absorbing polymer is sprayed in such a manner that the polymer spraying region in which the water-absorbing polymer is unevenly distributed is intermittently formed, the polymer is as designed. It can be easily and accurately confirmed whether or not it is sprayed on the surface, and a high-quality absorber can be produced economically.

FIG. 10 is a diagram for explaining one embodiment of the second invention.
In the embodiment of the second invention, as shown in FIG. 10, on the discontinuous first absorbent layer 181 which is molded by the first stacking drum 18 and conveyed at a predetermined interval, the second The discontinuous 2nd absorption layer 91 shape | molded by the fiber drum 9 is piled up. The first and second stacking drums 18 and 9 both continuously rotate in one direction, and the water-absorbing polymer and pulp fibers supplied in the scattered state are formed in the recesses 182 formed on the respective peripheral surfaces. , 92, and the deposit is discharged as the first absorption layer 181 or the second absorption layer 91.
In the absorbent body manufacturing apparatus 1 ′ shown in FIG. 10, a first stacking drum 18 molded on a core wrap sheet 180 that is continuously transported in the X direction in the drawing by a transport mechanism (not shown). The absorbent layer 181 is sequentially placed, and the second absorbent layer 91 formed by the second fiber drum 9 is sequentially placed on the first absorbent layer 181. The first and second absorbent layers stacked on each other are covered with the core wrap sheet 180 on the upper and lower surfaces, and then cut by a cutting device (not shown) to form an absorber (not shown).

In this embodiment, the capacitance type sensor 74 having the above-described configuration is arranged in the transport path of the laminated body 10B of the first and second absorption layers, and the arrangement position 74S of the sensor is set to the first and second positions. The output value of the sensor while the laminated body 10B of the absorption layer passes is recorded in the control device 7, and the deviation between the first absorption layer 181 and the second absorption layer 91 from the fluctuation pattern of the output value. Examine the presence and extent of
More specifically, the first stacking drum 18 rotates at the same peripheral speed as the core wrap sheet 180, and generates a pulse signal corresponding to a predetermined rotation amount on the first stacking drum 18. An encoder 71 is attached. The output value from the sensor arrangement position 74S is recorded in the control device 7 in association with the count time of the pulse signal. In addition, when the output value of the capacitance type sensor 74 exceeds a predetermined value and when the output value falls below the predetermined value, the front end and the rear end of the laminated body 10B of the first and second absorption layers are at the sensor 74. It detects as the passage time at which the arrangement position passes, and detects the difference in the count number of the pulse signal corresponding to each time.

As shown in FIG. 11 (a), as shown in FIG. 11 (a), as shown in FIG. 11 (a), as shown in FIG. When the first absorption layer and the second absorption layer do not overlap correctly, the difference H2 in the pulse signal count number becomes large.
Therefore, by monitoring the difference in the number of pulse signal counts corresponding to the time at which the front end and the rear end of the stacked body 10B of the first and second absorption layers pass through the position where the sensor 74 is disposed, the occurrence or occurrence of deviation occurs. The magnitude of the deviation can be inspected.
In this embodiment, when the occurrence of the deviation is detected, the control means 7 outputs a control signal S3 for increasing or decreasing the rotation of the servo motor 93 that drives the second stacking drum, whereby the subsequent control signal S3 is output. It correct | amends so that a shift | offset | difference may not arise in the laminated body 10B.
In addition, what is indicated by reference numeral 184 in FIG. 10 is a proximity switch, which detects a predetermined detector provided corresponding to each concave portion of the stacking drum 18 and intermittently outputs a pulse signal to the controller 7. Has been made to output. By using the pulse signal P5 from the proximity switch 184, the control device 7 can easily compare the fluctuation patterns of the output values, and can check for the presence and size of the deviation with higher accuracy.

As mentioned above, although one embodiment of the present invention (the 1st and 1st invention) was explained, the present invention is not restricted to the above-mentioned embodiment and can be changed suitably.
For example, as the cutting device, various known devices that can sequentially cut the belt-like fiber assembly 2 at a constant interval can be used.
As the fiber assembly in the first invention, various materials conventionally used in the production of absorbent bodies can be used, webs that have not been made into non-woven fabrics, non-woven fabrics by various manufacturing methods, woven fabrics, laminates thereof, and the like Can be used. As the water-absorbing polymer, various polymers conventionally used for absorbers can be used. The same applies to the core wrap sheet, but for example, liquid-permeable paper or non-woven fabric can be used. Further, instead of spraying the absorbent polymer so that the polymer is non-uniformly distributed in the flow direction of each polymer spray region, the polymer is uniformly distributed in the flow direction of each polymer spray region. It may be sprayed on.

The polymer intermittent spraying device according to the first aspect of the invention may be one in which the rotation is mechanically rotated at a non-constant speed using an eccentric cam instead of the one that is electrically rotated at a non-constant speed by a shift cam pattern. good.
In the second invention, a method for inspecting the presence / absence and degree of deviation between the first absorption layer and the second absorption layer from the fluctuation pattern of the output value is shown on both sides as shown in FIG. The control device discriminates between a variation pattern with a pattern and a variation pattern without a pattern on both sides as shown in FIG. 11B. In the case of a variation pattern with a shoulder, there is a deviation, and there is a variation pattern without a shoulder. In this case, it can be determined that there is no deviation. Moreover, you may combine as a 1st and 2nd absorption layer in 2nd invention the absorption layer containing a water absorbing polymer, and the absorption layer which does not contain a water absorbing polymer.
Moreover, the absorber in the first and second inventions may not include a core wrap sheet.

Further, in the first and second inventions, as a sensor that outputs a signal proportional to the density of the polymer, a photoelectric sensor that outputs a transmitted light amount, an image processing device, a color detection sensor (a colored polymer) instead of a capacitance sensor In this case, a fluorescent substance detection apparatus (for example, a fluorescent substance detection apparatus described in JP-A No. 10-38541) can also be used.
Further, it is also possible to use a device that outputs a signal proportional to the density of the polymer by image processing.

FIG. 1 is a diagram showing an outline of an absorbent body manufacturing apparatus used in one embodiment of the first invention. FIG. 2 is a plan view showing a fiber assembly having a polymer spray region in which water-absorbing polymers are sprayed in a non-uniform distribution. 3 is a cross-sectional view taken along line II-II in FIG. 4 is a cross-sectional view showing an intermittent polymer spraying device in the manufacturing apparatus shown in FIG. FIG. 5 is a schematic block diagram showing a configuration of a control device in the manufacturing apparatus shown in FIG. FIG. 6 is a diagram illustrating an example of a shift cam pattern. FIG. 7 is a diagram showing a change with time of an output value of the capacitance type sensor together with a pulse signal obtained from the encoder. FIG. 8 is a diagram for explaining a method of integrating the output values of the capacitance type sensor. FIG. 9 is a graph showing changes in the polymer amount for a large number of polymer spray regions. FIG. 10 is a diagram showing an outline of an absorbent body manufacturing apparatus used in one embodiment of the second invention. It is a figure which shows the time-dependent change of the output value of the electrostatic capacitance type sensor in one Embodiment of 2nd invention with the pulse signal obtained from an encoder.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,1 'Absorber manufacturing apparatus 2 Band-shaped fiber assembly 3 Polymer intermittent spraying apparatus 30 Water-absorbing polymer 6 Cutting apparatus 7 Control apparatus 74 Capacitance type sensor 81 First absorption layer 91 Second absorption layer

Claims (8)

The absorbent polymer is obtained by intermittently spraying the water-absorbing polymer on the belt-shaped fiber aggregate to be conveyed by the intermittent spraying device, and intermittently cutting the fiber assembly after the water-absorbing polymer is sprayed by the cutting device. A method for producing an absorbent,
Record the output value of the sensor that outputs a signal proportional to the density of the polymer placed in the transport path of the fiber assembly after polymer dispersion,
The amount of water-absorbing polymer present in each polymer spray region is determined by recording and integrating the output value of the sensor while the polymer spray region formed by spraying the absorbent polymer passes through the sensor placement position. The manufacturing method of the absorber to require.   The method for producing an absorbent body according to claim 1, wherein the absorbent polymer is sprayed so that the polymer is unevenly distributed in the flow direction of each polymer spray region.   The manufacturing method of the absorber of Claim 1 or 2 whose said sensor is an electrostatic capacitance type sensor.   The pulse signal corresponding to the amount of rotation of the rotating body rotating at a speed corresponding to the conveying speed of the fiber assembly is obtained by an encoder, and each pulse while each of the polymer spraying regions passes the sensor arrangement position The manufacturing method of the absorber in any one of Claims 1-3 which record and integrate | accumulate the output value of this sensor corresponding to 1 and obtain | require the quantity of the water absorbing polymer which exists in each polymer dispersion | spreading area | region. The encoder obtains a pulse signal corresponding to the amount of rotation of the rotating body that rotates at a speed corresponding to the conveyance speed of the fiber assembly, and the predetermined reference position of each polymer spray area is determined from the output value of the capacitance type sensor. Obtaining the passage time passing through the arrangement position of the sensor, further obtaining the cutting time of the fiber assembly by the cutting device by information from the detection means attached to the cutting device,
The shift between the position of each polymer spray region and the cutting position of the fiber assembly is determined from the difference in the number of counts of the pulse signal corresponding to the passage time and the pulse signal corresponding to the cutting time. The manufacturing method of the absorber in any one of these.   Record the amount of water-absorbing polymer in each polymer spraying area, and based on the record, determine the tendency of fluctuation in the polymer amount for a number of polymer spraying areas, and supply the amount of polymer supplied to the intermittent spraying device according to the determined trend The manufacturing method of the absorber in any one of Claims 1-5 which increases / decreases or maintains the amount as it is.   From the record of the output value of the capacitance type sensor, the distribution pattern of the water-absorbing polymer in each polymer spray region is obtained, and when the obtained distribution pattern is different from the preset distribution pattern, the preset distribution pattern The manufacturing method of the absorber in any one of Claims 1-6 which changes the spraying pattern of an intermittent spraying apparatus so that it may approach. A manufacturing method of an absorbent body comprising a laminating step of stacking a discontinuous second absorbent layer on a discontinuous first absorbent layer conveyed at a predetermined interval,
The first absorbent layer and the second absorbent layer contain a water-absorbing polymer;
It comprises an inspection process for inspecting the laminated state of the first absorption layer and the second absorption layer using a sensor that outputs a signal proportional to the density of the polymer. The output value of the sensor is recorded while the laminate of the first and second absorption layers passes, and the presence or absence of deviation between the first absorption layer and the second absorption layer from the fluctuation pattern of the output value And manufacturing method of the absorber, inspecting the degree.

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