JP2015078468A - Bulkiness recovery apparatus for nonwoven fabric and bulkiness recovery method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately adjust heating conditions in response to a conveyance speed of a nonwoven fabric in a bulkiness recovery apparatus for a nonwoven fabric.SOLUTION: There is provided an apparatus for recovering bulkiness of a nonwoven fabric by blowing hot air to the nonwoven fabric that is conveyed in a conveyance direction to heat. The apparatus includes: a conveyance unit for conveying the nonwoven fabric; a heating unit that includes a case member through which the conveyed nonwoven fabric enters and exits and a jetting port for jetting the hot air into a space inside the case member and is for blowing the hot air from the jetting port to a surface of the nonwoven fabric that is conveyed in the space inside the case member to heat; and a control unit for controlling a conveyance speed of the nonwoven fabric that is conveyed by the conveyance unit and changing conditions when the nonwoven fabric is heated according to the conveyance speed of the nonwoven fabric.

Description

  The present invention relates to a nonwoven fabric bulk recovery device and a bulk recovery method.

  Conventionally, sanitary napkins and disposable diapers have been used as absorbent articles. In addition, pet sheets included in the category of the absorbent article are also widely used as pet toilets.

  In such an absorbent article, a liquid-permeable top sheet is provided in a portion where the skin of a user or the like hits. In recent years, the top sheet is required to have high liquid repellency from the viewpoint of reducing stickiness to the skin, and a bulky nonwoven fabric is suitable as the material.

  Such a nonwoven fabric is manufactured in a strip shape by an appropriate method such as a card method, and then wound up into a roll shape and stored in the form of a nonwoven fabric. And when it is time to use, the nonwoven fabric raw material is carried into the manufacturing line of an absorbent article, and a nonwoven fabric is drawn | fed out from the raw material material in the same line, and is used as a material of a top sheet.

  On the other hand, when the non-woven fabric is wound on the non-woven fabric, the non-woven fabric is wound while applying tension in the winding direction in order to prevent meandering of the non-woven fabric. Therefore, the nonwoven fabric is usually wound up due to the tension. That is, the nonwoven fabric is compressed in the thickness direction, and the bulk is reduced. Therefore, even if the nonwoven fabric is fed out from the nonwoven fabric raw material in the absorbent article production line, the nonwoven fabric with reduced volume is only fed out and supplied, that is, it cannot meet the above-mentioned demand for the bulky nonwoven fabric. .

  In order to cope with this problem, Patent Document 1 discloses that a bulk recovery device is installed upstream of the absorbent article production line. Specifically, the nonwoven fabric fed from the nonwoven fabric is transported along a predetermined transport path, and a bulk recovery device is installed at a predetermined position of the transport path. And the apparatus blows a hot air with respect to the nonwoven fabric to pass, and heats the said nonwoven fabric, Thereby, the volume of a nonwoven fabric is recovered. Then, the non-woven fabric whose bulk has been recovered is sent out to the next treatment device of the same production line without being wound as it is.

JP 2004-137655 A

  However, in the bulk recovery device, when the nonwoven fabric is transported, the transport is not always performed at a constant speed. For example, when switching to a new nonwoven fabric after all the nonwoven fabrics have been fed out from the nonwoven fabric, the conveyance speed of the nonwoven fabric is temporarily reduced. If the conveying speed is reduced and hot air is blown onto the nonwoven fabric under the same conditions as normal, the nonwoven fabric may be heated more than necessary and stretch in the conveying direction, or bulk recovery may not be performed normally. There is.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to appropriately adjust the heating conditions according to the conveyance speed of the nonwoven fabric in the nonwoven fabric bulk recovery device. .

The main invention for achieving the above object is:
A device for recovering the bulk of the nonwoven fabric by blowing hot air on the nonwoven fabric conveyed in the conveying direction and heating the nonwoven fabric, a conveyance unit for conveying the nonwoven fabric, a case member for the nonwoven fabric to be conveyed in and out, and the case A heating section for spraying the hot air into a space inside the member, and heating the surface of the nonwoven fabric conveyed in the space inside the case member by blowing the hot air from the spray port; and The bulk of the nonwoven fabric, comprising: a control unit that controls a transport speed of the nonwoven fabric transported by the transport unit and changes a condition for heating the nonwoven fabric according to a transport speed of the nonwoven fabric. It is a recovery device.
Other features of the present invention will become apparent from the description of the present specification and the accompanying drawings.

  According to the present invention, in the nonwoven fabric bulk recovery device, the heating conditions can be appropriately adjusted according to the conveyance speed of the nonwoven fabric.

FIG. 1A is an external perspective view of a pet sheet 1 as an example of an absorbent article, and FIG. 1B is an enlarged perspective view when the sheet 1 is cut along line BB in FIG. 1A. It is a schematic side view of the bulk recovery apparatus 20 of this embodiment. FIG. 3A is an explanatory diagram of the heating unit 60 that is a main part of the bulk recovery device 20, and FIG. 3B is a cross-sectional view taken along line BB in FIG. 3A. It is a figure showing the control flow about the conveyance part 30 at the time of performing the bulk recovery operation | movement of the nonwoven fabric 3 using the bulk recovery apparatus 20. FIG. It is a figure showing the control flow about the heating part 60 at the time of performing the bulk recovery operation | movement of the nonwoven fabric 3 using the bulk recovery apparatus 20. FIG. It is a figure showing the modification of the control flow about the heating part 60 at the time of performing the bulk recovery operation | movement of the nonwoven fabric 3 using the bulk recovery apparatus 20. FIG. It is explanatory drawing of the width sensor. It is a figure explaining an example of the method of discharging hot air from the inside of the case member 62 forcibly outside.

At least the following matters will become apparent from the description of the present specification and the accompanying drawings.
A device for recovering the bulk of the nonwoven fabric by blowing hot air on the nonwoven fabric conveyed in the conveying direction and heating the nonwoven fabric, a conveyance unit for conveying the nonwoven fabric, a case member for the nonwoven fabric to be conveyed in and out, and the case A heating section for spraying the hot air into a space inside the member, and heating the surface of the nonwoven fabric conveyed in the space inside the case member by blowing the hot air from the spray port; and The bulk of the nonwoven fabric, comprising: a control unit that controls a transport speed of the nonwoven fabric transported by the transport unit and changes a condition for heating the nonwoven fabric according to a transport speed of the nonwoven fabric. Recovery device.

  According to such a nonwoven fabric bulk recovery device, the heating conditions can be appropriately adjusted according to the conveyance speed of the nonwoven fabric. Thereby, even when the conveyance speed of a nonwoven fabric becomes slow, it can suppress that a nonwoven fabric is heated excessively, and normal bulk recovery operation | movement can be implement | achieved.

  Such a nonwoven fabric bulk recovery device includes a hot air supply unit that supplies the hot air to the heating unit, and the control unit is configured to supply the hot air to the heating unit in accordance with a conveyance speed of the nonwoven fabric. It is desirable to change.

  According to such a nonwoven fabric bulk recovery device, by appropriately changing the amount of hot air blown to the nonwoven fabric, it is possible to adjust the amount of heat per unit time applied to the conveyed nonwoven fabric in the bulk recovery operation. . Thereby, normal bulk recovery operation | movement is realizable, suppressing that a nonwoven fabric extends in a conveyance direction.

  In this nonwoven fabric bulk recovery apparatus, it is preferable that the control unit changes a temperature of the hot air supplied to the heating unit in accordance with a conveyance speed of the nonwoven fabric.

  According to such a nonwoven fabric bulk recovery device, the amount of heat per unit time applied to the conveyed nonwoven fabric can be adjusted in the bulk recovery operation by appropriately changing the temperature of the hot air blown onto the nonwoven fabric. . Thereby, normal bulk recovery operation | movement is realizable, suppressing that a nonwoven fabric extends in a conveyance direction.

  In such a nonwoven fabric bulk recovery device, the transport unit is driven and rotated in order to transport the nonwoven fabric to positions on both sides in the transport direction of the heating unit in a transport path through which the nonwoven fabric is transported. It is desirable to have a drive roller, and the control unit changes the peripheral speed value of the drive roller located on the upstream side of the two drive rollers according to the conveyance speed of the nonwoven fabric.

  According to such a nonwoven fabric bulk recovery device, when the amount of heat applied to the nonwoven fabric increases, by adjusting the tension applied to the nonwoven fabric, it becomes difficult for the nonwoven fabric to stretch in the transport direction, thereby realizing a normal bulk recovery operation. be able to.

  This non-woven fabric bulk recovery device is a width sensor that outputs information related to the widthwise dimension by measuring the widthwise dimension of the nonwoven fabric at a position downstream of the heating unit in the transport direction. It is desirable that the control unit change a condition for heating the nonwoven fabric based on the conveyance speed of the nonwoven fabric and the information output from the width sensor.

  According to such a bulk recovery device for nonwoven fabrics, it is possible to acquire information related to the widthwise dimensions of the nonwoven fabric during the bulk recovery operation. By grasping the actual influence due to the amount of heat applied to the nonwoven fabric from the information regarding the dimensions in the width direction and appropriately changing the heating conditions, it is possible to suppress an excessive amount of heat being applied to the nonwoven fabric.

  In this non-woven fabric bulk recovery device, a part of the wall portion constituting the case member is movable to open the space inside the case member to the atmosphere, and the control unit is configured to transfer the non-woven fabric. It is desirable to move a part of the wall surface and discharge the hot air from the space inside the case member when the air velocity becomes slower than a predetermined speed.

  According to such a bulk recovery device for nonwoven fabric, hot air can be discharged from the case member to the outside at once. By directly discharging the hot air to the outside of the case member, the amount of heat applied to the nonwoven fabric can be greatly reduced in a short time. Thereby, it is possible to suppress an excessive amount of heat from being applied to the nonwoven fabric even in an emergency such as when the conveyance speed of the nonwoven fabric is rapidly decreased.

  In this nonwoven fabric bulk recovery device, an opening when the nonwoven fabric is transported is provided at an opening on one end side in the transport direction of the case member, and an opening on the other end side in the transport direction of the case member Is provided with an outlet when the non-woven fabric is conveyed, the injection port is provided at a portion on the inlet side of the case member, and the hot air jetted from the jet port is out of both surfaces of the non-woven fabric. It is desirable that the fluid flows from the upstream side in the transport direction to the downstream side in the transport direction while contacting one surface.

  According to such a nonwoven fabric bulk recovery device, the hot air sprayed into the case member moves so as to flow through the surface of the nonwoven fabric, so that the situation where the hot air compresses the nonwoven fabric from the thickness direction is avoided, Bulk recovery can be performed smoothly. Moreover, bulk recovery can be accelerated | stimulated by generating a turbulent flow by making the wind speed of a hot air sufficiently larger than the conveyance speed of a nonwoven fabric, and heating a nonwoven fabric efficiently.

  Moreover, it is a method of recovering the bulk of the nonwoven fabric by blowing hot air on the nonwoven fabric conveyed in the conveying direction and heating the nonwoven fabric, a step of conveying the nonwoven fabric, a case member in which the conveyed nonwoven fabric enters and exits, and Using a heating unit having an injection port for injecting the hot air into the space inside the case member, the hot air is blown from the injection port to the surface of the nonwoven fabric transported in the space inside the case member and heated. And a step of changing the conditions for heating the nonwoven fabric in accordance with the conveyance speed of the nonwoven fabric, and a method for recovering the bulk of the nonwoven fabric becomes apparent.

  According to such a bulk recovery method of the nonwoven fabric, the heating conditions can be appropriately adjusted according to the conveyance speed of the nonwoven fabric. Thereby, even when the conveyance speed of a nonwoven fabric becomes slow, it can suppress that a nonwoven fabric is heated excessively, and normal bulk recovery operation | movement can be implement | achieved.

=== This Embodiment ===
<About non-woven fabrics subject to bulk recovery>
The bulk recovery device 20 and the bulk recovery method for the nonwoven fabric 3 of the present embodiment target the nonwoven fabric 3 to be the top sheet 3 of the pet sheet 1.

  FIG. 1A is an external perspective view of a pet sheet 1 as an example of an absorbent article, and FIG. 1B is an enlarged perspective view when the sheet 1 is cut along line BB in FIG. 1A.

  The pet sheet 1 is used for excretion processing of animals such as dogs and cats, and is laid on a floor or the like as shown in FIG. 1A. The pet sheet 1 includes, for example, a liquid-permeable top sheet 3 having a rectangular shape in plan view, a liquid-impermeable back sheet 5 having substantially the same shape, and liquid absorption interposed between these sheets 3 and 5. And an absorbent body 4. The absorbent body 4 is bonded to both the top sheet 3 and the back sheet 5 with a hot melt adhesive or the like, and the top sheet 3 and the back sheet 5 are part 3e that protrudes laterally from the absorbent body 4. , 5e, that is, the outer peripheral edge portions 3e, 5e of the sheets 3, 5 are joined by a hot melt adhesive or the like.

  As shown in FIG. 1B, the absorbent body 4 has an absorbent core 4c formed by laminating liquid absorbent fibers such as pulp fibers and a superabsorbent polymer (so-called SAP) in a substantially rectangular shape in plan view. The core 4c may be covered with two liquid-permeable covering sheets 4t1 and 4t2 such as tissue paper, and in this example, this is the case. That is, it is covered with one coating sheet 4t1 from the skin side surface, and is covered with another coating sheet 4t2 from the non-skin side surface. In some cases, the entire surface of the absorbent core 4c may be covered with a single covering sheet.

  The back sheet 5 is, for example, a film material such as polyethylene (hereinafter referred to as PE), polypropylene (hereinafter referred to as PP), and polyethylene terephthalate (hereinafter referred to as PET). However, it is not limited to these, and any liquid-impermeable sheet can be used.

  The top sheet 3 is made of the nonwoven fabric 3. In this example, one surface 3b of the both surfaces 3a and 3b of the nonwoven fabric 3 is a substantially flat surface, but the other surface 3a has a corrugated shape. That is, the linear groove 3t and the linear protrusion 3p are alternately formed. The protrusions 3p, 3p,... Are formed by swelling the fibers that originally existed in the groove portion 3t by the well-known air flow blowing process (see JP 2009-11179A). It is formed in a sparse state with a large gap between fibers. Thereby, the nonwoven fabric 3 is bulky as a whole. Further, a plurality of through holes 3h, 3h... Penetrating in the thickness direction may be formed in the groove 3t, and in this example, this is the case.

The average basis weight of the nonwoven fabric 3 is, for example, 10 to 200 (g / m ² ), and the average basis weight of the central portion of the protrusion 3p is, for example, 15 to 250 (g / m ² ). The average basis weight of the bottom is 3 to 150 (g / m ² ).

  Moreover, as the fiber of the nonwoven fabric 3, a composite fiber having a core-sheath structure in which the core is PET and the sheath is PE is suitable, but other thermoplastic resin fibers may be used. For example, a composite fiber having a core-sheath structure in which the core is PP and the sheath is PE may be used, or a fiber having a side-by-side structure may be used, or a single fiber made of a single thermoplastic resin may be used.

  Furthermore, the nonwoven fabric 3 may have crimped fibers. The crimped fiber is a fiber having a crimped shape such as a zigzag shape, an Ω shape, or a spiral shape.

  Moreover, about the fiber length of the fiber contained in the nonwoven fabric 3, it selects from the range of 20-100 mm, for example, and selects the fineness from the range of 1.1-8.8 (dtex), for example.

<Description of bulk recovery device>
The pet sheet 1 is manufactured on the production line of the pet sheet 1, and the nonwoven fabric 3 for the top sheet 3 is carried into the production line in the form of a nonwoven fabric 3R (FIG. 2). That is, the nonwoven fabric 3 having the protrusions 3p described above is stored in a state where it is once wound up in a roll shape, and the nonwoven fabric raw material 3R is carried into the production line of the pet sheet 1 from the storage location. And it is attached to the feeding apparatus 35 which the same production line comprises, and is drawn out as a material of the top sheet 3.

  However, as described above, in the nonwoven fabric original fabric 3R, the bulk of the nonwoven fabric 3 may be crushed. Therefore, a bulk recovery device 20 is provided in this production line.

  FIG. 2 is a schematic side view of the bulk recovery device 20. Moreover, FIG. 3A is explanatory drawing of the heating part 60 which makes the principal part of the bulk recovery apparatus 20, and FIG. 3B is BB sectional drawing in FIG. 3A. 2 and 3A, the heating unit 61 that forms the main part of the heating unit 60 is shown in a sectional view.

  As shown in FIG. 2, the bulk recovery device 20 feeds the nonwoven fabric 3 from the nonwoven fabric raw material 3 </ b> R and transports the nonwoven fabric 3 along a predetermined transport path, and heating the non-woven fabric 3 at a predetermined position on the transport path. And a control unit 100 that controls the transport unit 30 and the heating unit 60. Then, the nonwoven fabric 3 heated by the heating unit 60 and recovered in bulk is sent to a junction with another intermediate product related to the pet sheet 1 located downstream in the conveying direction, for example, a junction with the absorber 4. And joined to the intermediate product at the junction.

  Incidentally, as with the bulk recovery device 20, various devices (not shown) on the production line are supported by appropriate support members and arranged in the same line. In this example, a so-called end plate (not shown) is used as an example of the support member. The end plate is a plate member that is erected vertically on the floor of the production line, and the end plate has a vertical surface (a surface in which the normal direction faces the horizontal direction). Supported in a cantilevered state.

  Hereinafter, the normal direction of the vertical plane is referred to as “CD direction”. In FIG. 2, the CD direction is a direction that penetrates the paper surface of FIG. 2. More specifically, the CD direction is a direction that penetrates the paper surface of FIG. 2 among arbitrary directions in the horizontal plane. It is suitable. Moreover, since the fed nonwoven fabric 3 is basically conveyed in a posture in which the width direction of the nonwoven fabric 3 faces the CD direction, the conveyance direction of the nonwoven fabric 3 faces an arbitrary direction orthogonal to the CD direction. It will be. In addition, this support member is not limited to any end plate, and other support members may be used.

(Conveying unit 30)
The transport unit 30 includes a plurality of transport rollers 32, 32... That define the transport path of the nonwoven fabric 3. The transport unit 30 includes feeding devices 35 and 35, a material contact device 36, an accumulator device 37, and a tension control device 38, and the transport path is from upstream to downstream in the transport direction. In this order, the devices 35, 35, 36, 37, and 38 are arranged side by side.

  Each of the transport rollers 32, 32... Is supported so as to be rotatable around a rotation axis along the CD direction, whereby the nonwoven fabric 3 is transported in a posture in which its width direction is directed to the CD direction.

  Note that some of the transport rollers 32, 32... Are drive rollers 32u, 32d that are driven and rotated by a servo motor as a drive source, and the other transport rollers 32, 32. It is a driven roller which does not have a drive source, ie, a roller which rotates with a rotational force obtained by contact with the nonwoven fabric 3 being conveyed.

  The driving rollers 32u and 32d are provided at respective positions on both sides of the heating unit 60 (more precisely, a heating unit 61 described later) in the transport path. Hereinafter, the drive roller 32u positioned upstream in the transport direction from the heating unit 60 is referred to as "upstream drive transport roller 32u", and the drive roller 32d positioned downstream in the transport direction from the heating unit 60. Is referred to as “downstream drive conveyance roller 32d”. And the conveyance state of the nonwoven fabric 3 in the heating part 60 is adjusted by controlling the rotation operation | movement of these upstream drive conveyance rollers 32u and the downstream drive conveyance roller 32d by the control part 100 mentioned later.

  The feeding device 35 is a device for feeding the nonwoven fabric 3 from the nonwoven fabric raw fabric 3R, and has a rotation axis along the CD direction. And the nonwoven fabric raw fabric 3R is rotatably supported by the said rotating shaft. The rotating shaft is driven and rotated by, for example, a servo motor (not shown) as a drive source, and thereby the nonwoven fabric 3 is fed out from the nonwoven fabric original 3R. The servo motor performs a feeding operation in cooperation with the accumulator device 37. This will be described later.

  Two such feeding devices 35 and 35 are provided as a plurality of examples. Basically, they are used alternately. That is, while the one unwinding device 35 is unwinding the nonwoven fabric 3, the other unwinding device 35 is in the standby state, and when the non-woven fabric raw material 3R of the one unwinding device 35 disappears, the unwinding device 35 in the waiting state Is configured to start feeding the nonwoven fabric 3. Since the feeding device 35 is well known, detailed description thereof will be omitted.

  The material adhering device 36 is configured so that the tail end 3ee of the nonwoven fabric 3 of the raw fabric 3R is transferred to the waiting feeding device 35 shortly before the feeding device 35 during feeding finishes feeding all the nonwoven fabrics 3R of the nonwoven fabric raw fabric 3R. It is an apparatus joined to the front-end | tip part 3es of the nonwoven fabric 3 of the nonwoven fabric raw fabric 3R attached. And thereby, the nonwoven fabric 3 can be let out continuously without interruption. Since the material contact device 36 is also well known, detailed description thereof will be omitted.

  The accumulator device 37 is a device that accumulates the non-woven fabric 3 fed out from the feeding device 35 so as to be discharged downstream in the transport direction. Then, when the nonwoven fabric 3 is not delivered from the delivery device 35 as in the joining process by the material joining device 36, the delivery device is provided by discharging the nonwoven fabric 3 accumulated in the accumulator device 37 itself downstream. The influence of the 35 feeding stop is made difficult to exert downstream. In addition, when the feeding stop of the feeding device 35 is released, the feeding device 35 is more than the conveyance speed value (m / min) of the nonwoven fabric 3 at the position immediately downstream of the accumulator device 37 until the specified accumulation amount is reached. The non-woven fabric 3 is fed out at a fast speed value (m / min), whereby the non-woven fabric 3 that has been dispensed while the feeding is stopped is accumulated in the accumulator device 37.

  In this example, the accumulator device 37 includes a fixed roller group G37s composed of a plurality of rollers 37s, 37s... Fixed at a fixed position, and a plurality of rollers 37m, 37m. Movable roller group G37m. The nonwoven fabric 3 is alternately wound around the rollers 37s belonging to the fixed roller group G37s and the rollers 37m belonging to the movable roller group G37m, thereby forming a loop L3 of the nonwoven fabric 3 to form the nonwoven fabric 3 Accumulate.

  Here, the movable roller group G37m reciprocates in the horizontal direction according to the magnitude (N) of the tension of the nonwoven fabric 3. That is, when the tension of the nonwoven fabric 3 is greater than a preset tension setting value (N), the movable roller group G37m moves so as to reduce the loop L3, thereby accumulating. The non-woven fabric 3 is discharged and supplied downstream. On the other hand, when the magnitude | size of the tension | tensile_strength of the nonwoven fabric 3 is smaller than said setting value, it moves so that the loop L3 may become large, and, thereby, the nonwoven fabric 3 is accumulate | stored. Therefore, at the position immediately downstream of the accumulator device 37, the magnitude of the tension of the nonwoven fabric 3 is substantially maintained at the above set value. In this sense, the accumulator device 37 is similar to a tension control device 38 to be described later. Also plays the function. Since this accumulator device 37 is also well known, further detailed description is omitted.

  The tension control device 38 is disposed at a position between the accumulator device 37 and the upstream drive conveyance roller 32u described above. And the magnitude | size (N) of the tension | tensile_strength of the nonwoven fabric 3 in the position immediately downstream of the tension control apparatus 38 is adjusted so that it may become a predetermined target value (N).

  The tension control device 38 is configured using a so-called dancer roll 38dn. That is, it is provided at a position between a pair of fixed rolls 38 s, 38 s fixed at a fixed position with a gap in the conveying direction between each other, and in a direction perpendicular to the CD direction. The dancer roll 38dn is provided so as to be capable of reciprocating, and the drive roll 38k is provided upstream of the dancer roll 38dn in the transport direction. The non-woven fabric 3 is wound around the pair of fixed rolls 38s and 38s, the dancer roll 38dn, and the drive roll 38k, and is also wound around the pair of fixed rolls 38s and 38s and the dancer roll 38dn. The nonwoven fabric 3 thus formed forms a loop L3dn. A force corresponding to twice the target value of the tension of the nonwoven fabric 3 is applied to the dancer roll 38dn in the direction in which the loop L3dn becomes larger in the reciprocating direction. Therefore, when the tension of the nonwoven fabric 3 is larger than the target value, the dancer roll 38dn moves so that the loop L3dn becomes smaller. On the other hand, when the tension of the nonwoven fabric 3 is smaller than the target value. The dancer roll 38dn moves so that the loop L3dn becomes large. On the other hand, the drive roll 38k is driven and rotated by a servo motor. The motor rotates the drive roll 38k so that the size of the loop L3dn becomes a predetermined value and feeds the nonwoven fabric 3. For example, when it is larger than the predetermined value, the peripheral speed value (m / min) of the driving roll 38k is decreased, while when it is smaller than the predetermined value, the peripheral speed value of the driving roll 38k is increased. And thereby, the magnitude | size of the tension | tensile_strength of the nonwoven fabric 3 of the position immediately downstream of the tension control apparatus 38 is adjusted so that it may become a target value.

(Heating unit 60)
The heating unit 60 includes a heating unit 61 that heats the nonwoven fabric 3 being conveyed by blowing hot air and a hot air supply device 67 that supplies the hot air to the heating unit 61.

  The heating unit 61 includes a case member 62 having both ends in the longitudinal direction opened, and a plurality of guide rollers 64, 64, which are provided outside the case member 62 and guide the nonwoven fabric 3 to reciprocate within the case member 62. 64. The forward path and the return path of the transport path of the nonwoven fabric 3 are each formed in a straight line in the case member 62 by the guide rollers 64, 64, 64. Further, as shown in FIG. 3A, a partition wall member 63 that forms a wall surface along the conveyance direction of the nonwoven fabric 3 is provided inside the case member 62. The partition member 63 divides the space in the case member 62 into a forward space SP62a and a backward space SP62b. In other words, the outward space SP62a and the backward space SP62b are isolated from each other so that air cannot pass between them. Further, due to the separation by the partition wall member 63, both the forward path inlet 62 ain and the backward path outlet 62 bout of the nonwoven fabric 3 are respectively formed at one end of the longitudinal ends of the case member 62. At the other end, both an outlet 62aout for the forward path and an inlet 62bin for the return path of the nonwoven fabric 3 are formed.

  Out of the wall surfaces 63wa and 63wb of the partition wall member 63, the wall surface 63wa adjacent to the outbound path space SP62a (hereinafter also referred to as the outbound path wall surface 63wa) and the return path space SP62b of the both wall surfaces 63wa and 63wb. Adjacent wall surfaces 63wb (hereinafter also referred to as return wall surfaces 63wb) are provided in parallel with the transport direction and the CD direction, respectively, so that the outbound wall surface 63wa and the return wall surface 63wb are respectively surfaces of the nonwoven fabric 3. And almost parallel. In the forward wall surface 63wa, the upstream portion of the forward passage (corresponding to the “portion on the inlet side of the case member”) is provided with a slit-like injection port 63Na that is long in the CD direction. Of the return wall surface 63wb, the upstream portion of the return path (corresponding to the “portion on the inlet side of the case member”) is also provided with a slit-like injection port 63Nb that is long in the CD direction.

  More specifically, the partition wall member 63 has pressure chambers R63a and R63b inside corresponding to the above-described portions. And hot air is supplied to each pressure chamber R63a, R63b from said hot air supply apparatus 67. FIG. Each of the pressure chambers R63a and R63b has a cross-sectional shape (a shape in a cross-section in which the CD direction is a normal direction) having a tapered shape that becomes generally narrower toward the downstream side in the transport direction. The front end portion of the shape communicates with the corresponding space SP62a, SP62b for the forward path or the return path, and thereby the front end portion functions as the injection ports 63Na, 63Nb. And according to such injection port 63Na, 63Nb, while facing one surface of the both surfaces of the nonwoven fabric 3, hot air is directed toward the downstream side in the transport direction with an acute inclination angle θ with respect to the same surface. Spray.

  In addition, a discharge port 63ha that opens to the outward path space SP62a is provided in a downstream portion of the outward path wall surface 63wa in the direction in which hot air is ejected from the ejection port 63Na. In the case of FIG. 3A, the discharge port 63ha is provided in the partition member 63 further downstream in the transport direction than the injection port 63Nb and the pressure chamber R63b (corresponding to “portion on the outlet side of the case member”). Similarly, a discharge port 63hb that opens to the return space SP62b is provided in a downstream portion of the return wall surface 63wb in the direction in which hot air is injected from the injection port 63Nb. In the case of FIG. 3A, the discharge port 63hb is provided in the partition member 63 further downstream in the transport direction than the injection port 63Na and the pressure chamber R63a (corresponding to “portion on the outlet side of the case member”).

  With such a configuration, the hot air jetted from the forward jet port 63Na comes into contact with the surface of the nonwoven fabric 3 with a velocity component on the downstream side in the transport direction, and flows through the same surface as it is, so that the space for the forward pass It is discharged out from the discharge port 63ha located on the most downstream side in the transport direction in SP62a. A part of the hot air is discharged from the outlet 62aout. Further, the hot air jetted from the return path injection port 63Nb comes into contact with the surface of the nonwoven fabric 3 with a velocity component on the downstream side in the transport direction, and flows through the same surface as it is in the return path space SP62b. It is discharged outside through a discharge port 63hb located on the most downstream side in the transport direction. A part of the hot air is discharged outside through the outlet 62bout.

  Thus, since the hot air sprayed into the case member 62 moves so as to flow on the surface of the nonwoven fabric 3, a situation in which the hot air compresses the nonwoven fabric 3 from the thickness direction of the nonwoven fabric 3 is effectively avoided. Thereby, bulk recovery can be performed smoothly.

Moreover, depending on the adjustment of the air volume (m ³ / min) of the hot air, the wind speed value vw (m / min) of the hot air can be made larger than the conveyance speed value v3 (m / min) of the nonwoven fabric 3. And if it does in that way, the hot air injected from each injection port 63Na, 63Nb will pass the nonwoven fabric 3 so that the surface of the nonwoven fabric 3 may slip, and is finally discharged | emitted outside from each exit 62aout, 62bout. . Therefore, based on the relative speed difference between the hot air and the nonwoven fabric 3, the hot air can be reliably made into a turbulent state. As a result, the heat transfer efficiency can be dramatically improved, the nonwoven fabric 3 can be heated efficiently, and the bulk can be quickly recovered. Moreover, since the fiber of the nonwoven fabric 3 is loosened at random by the turbulent hot air, this also promotes the recovery of the bulk.

Incidentally, the wind velocity value vw (m / min) of the hot air is, for example, the amount of air (m ³ / min) supplied to the outward space SP62a or the backward space SP62b, and the outward space SP62a or the backward space. It is a value obtained by dividing by the cross-sectional area of SP62b (that is, the area of the cross section with the transport direction as the normal direction).

  Desirably, the magnitude relationship between the wind speed value vw and the transport speed value v3 as described above is established over the entire length in the transport direction of the spaces SP62a and SP62b for the forward path or the return path. However, it does not necessarily have to be established over the entire length. That is, even in a part of each of the spaces SP62a and SP62b, if the above magnitude relationship is established, the operational effects relating to the turbulent state can be enjoyed accordingly.

  In addition, the shape of each of the outlets 63Na and 63Nb for the forward path and the backward path is a rectangle whose longitudinal direction is in the CD direction. The dimension in the CD direction of the outward injection port 63Na is the same as the dimension in the CD direction of the outward path SP62a, and the dimension in the CD direction of the return injection port 63Nb is the same as that of the return space SP62b. Although it is set to the same value as the dimension in the CD direction, it is not limited to this. For example, the injection ports 63Na and 63Nb may be smaller. However, desirably, the dimension in the CD direction of each of the ejection ports 63Na and 63Nb is larger than the dimension in the width direction of the nonwoven fabric 3 (dimension in the CD direction). It is suppressed.

  In addition, the dimension in the short direction of each of the ejection ports 63Na and 63Nb (the dimension in the direction orthogonal to the dimension in the CD direction) is set by selecting an arbitrary value from a range of 1 mm to 10 mm, for example.

  Furthermore, the angle θ formed by the hot air injection direction with respect to the conveyance direction of the nonwoven fabric 3 at the positions of the injection ports 63Na and 63Nb is preferably in the range of 0 ° to 30 °, and more preferably It should be within the range of 0 ° to 10 ° (FIG. 3A). And if it becomes like this, a hot air can be reliably flowed along the surface of the nonwoven fabric 3. FIG.

  Incidentally, in the example of FIG. 2, the heating unit 61 is a horizontal type in which the longitudinal direction of the case member 62 faces the horizontal direction, whereby the forward path and the return path related to the conveyance path of the nonwoven fabric 3 are leveled. There is no limitation to this. That is, depending on the case, it may be a vertical type. More specifically, the longitudinal direction of the case member 62 may be directed in the vertical direction, and thereby the forward path and the return path related to the conveyance path of the nonwoven fabric 3 may be vertical. Furthermore, the case member 62 may be disposed with the longitudinal direction inclined from both the vertical direction and the horizontal direction, depending on the convenience of the layout. However, the vertical installation type is excellent in that the plane space required for installing the heating unit 61 is small.

  The hot air supply device 67 includes a blower 67b and a heater 67h. Then, hot air is generated by heating the air generated by the blower 67b by the heater 67h, and the hot air is generated through a suitable pipe member 67p, and the pressure chamber of the partition wall member 63 in the case member 62 of the heating unit 61 described above. Supply to R63a, R63b. And hot air is injected from the injection ports 63Na and 63Nb via the pressure chambers R63a and R63b.

The blower 67b includes, for example, an impeller 67i that rotates using a motor as a drive source, and an inverter (not shown) that adjusts the rotation speed (rpm) of the motor. And the control part 100 mentioned later can perform VVVF inverter control by this, As a result, adjusts an air volume (m < ³ > / min) to arbitrary value via the change of the rotation speed (rpm) of the impeller 67i. Is possible.

  The heater is an electric heater that is heated with, for example, electric power (kW), and the temperature of the hot air can be adjusted to an arbitrary value by changing the amount of input electric power. In addition, about the temperature of hot air, it is good that the temperature in the position of the jet nozzles 63Na and 63Nb is at least 50 ° C. lower than the melting point of the thermoplastic resin fibers contained in the nonwoven fabric 3 and lower than the melting point. . And if it is set to such a range, the volume can be reliably recovered while preventing the thermoplastic resin fibers from melting.

  As shown in FIG. 3A, the heater 67h may be built in the blower 67b or may be provided outside the blower 67b. When the heater 67h is provided outside, the heaters 67ha and 67hb may be disposed in the vicinity of the case member 62 of the heating unit 61, as indicated by a two-dot chain line in FIG. 3A. In the temperature adjustment, the responsiveness can be improved. In this case, more preferably, heaters 67ha and 67hb are provided for each of the injection ports 63Na and 63Nb. That is, it is preferable to provide the heater 67ha corresponding to the outward injection port 63Na, and separately provide the heater 67hb corresponding to the return injection port 63Nb. In this way, the temperature of the hot air can be individually adjusted for each of the injection ports 63Na and 63Nb, and as a result, the condition setting for the bulk recovery process can be performed more finely.

  The heaters 67, 67ha, and 67hb are not limited to electric heaters, and can be applied as long as they can heat the air that forms the wind.

  In this example, “wind” refers to the flow of air, but in a broad sense, it includes a flow of gas such as nitrogen gas or inert gas in addition to the flow of air. That is, nitrogen gas or the like may be blown from the injection ports 63Na and 63Nb.

  In the present embodiment, one end side of the collection tube member 69 is connected to the outlets of the discharge ports 63ha and 63hb, and the other end side of the collection tube member 69 communicates with the suction side portion 67bs of the blower 67b. Thereby, the hot air flowing through the spaces SP62a and SP62b is collected and returned to the suction side portion 67bs of the blower 67b via the collecting pipe member 69. The recovered hot air is heated by the heater 67h with the addition of outside air and then supplied to the heating unit 61 again. By collecting the hot air, part of the energy can be reused while suppressing adverse effects on other intermediate products in the vicinity when the hot air is discharged in the heating unit 61.

  Incidentally, in the case of FIG. 3A, foreign matter such as fiber scraps of the nonwoven fabric 3 passes through the collection tube member 69 and is sent to the heater 67h in the blower 67b, which may cause fusion. Therefore, it is desirable to insert a filter member for preventing foreign matter inhalation having a mesh shape, for example, between the suction side portion 67bs of the blower 67b and the collecting pipe member 69. In the case of the example in FIG. 3A as well, foreign matter such as paper dust in the production line may be mixed with the outside air and sucked from the suction side portion 67bs. Therefore, it is desirable that the same type of filter member be used for the suction side portion 67bs. It is good to provide.

  Moreover, in the example of FIG.2 and FIG.3, the heating unit 61 is a horizontal installation type in which the longitudinal direction of the case member 62 faces the horizontal direction, and thereby, the forward path and the return path related to the conveyance path of the nonwoven fabric 3 are arranged. Although it is level, it is not limited to this. That is, depending on the case, it may be a vertical type. More specifically, the longitudinal direction of the case member 62 may be directed in the vertical direction, and thereby the forward path and the return path related to the conveyance path of the nonwoven fabric 3 may be vertical. Furthermore, the case member 62 may be disposed with the longitudinal direction inclined from both the vertical direction and the horizontal direction, depending on the convenience of the layout. However, the vertical installation type is excellent in that the plane space required for installing the heating unit 61 is small.

(Control unit 100)
The control unit 100 is, for example, a computer or a PLC (programmable logic controller), and includes a processor and a memory. Then, the control program stored in advance in the memory is read out and executed by the processor, thereby controlling the transport unit 30 and the heating unit 60. 2 and 3, the connection state between the control unit 100, the transport unit 30, and the heating unit 60 is illustrated in a simplified manner.

  In the bulk recovery device 20 of the present embodiment, the transport operation of the nonwoven fabric 3 is controlled based on a preset transport speed. First, a program for controlling the conveyance speed of the nonwoven fabric 3 is set in the memory of the control unit 100 before the operation of the bulk recovery device is started. For example, the conveyance speed value v3 of the nonwoven fabric 3 is about 100 to 600 (m / min), increases at a predetermined acceleration from the start of operation, and is set to be about v3 = 500 (m / min) during steady operation. Is done. Further, during the operation, it is necessary to switch the nonwoven fabric raw material 3R, and the conveyance speed is reduced to about v3 = 300 (m / min) while the material welding device 36 is operating. Also, when a malfunction (for example, the width dimension of the nonwoven fabric 3 becomes shorter than a predetermined value) or the like occurs while gradually increasing the transport speed from the start of operation, the transport speed is reduced at a predetermined rate. There is a case. The control unit 100 controls the operation of the drive rollers 32u and 32d and the feeding device 35 based on such a speed control program, and conveys the nonwoven fabric 3 at the set speed.

  Moreover, the control part 100 changes the conditions at the time of heating the nonwoven fabric 3 in bulk recovery operation | movement based on the conveyance speed of the nonwoven fabric 3. FIG. Conditions for heating the nonwoven fabric 3 include the amount and temperature of hot air supplied to the heating unit 61 during the bulk recovery operation, the feed amount of the nonwoven fabric 3 being conveyed, and the like. These specific control methods will be described later.

<Regarding adjustment of heating conditions>
In the bulk recovery device 20 of the present embodiment, the bulk recovery is performed by blowing hot air against the nonwoven fabric 30 transported inside the case member 62 of the heating unit 61. In order to perform normal bulk recovery, an appropriate amount of heat needs to be applied to the nonwoven fabric 3 being conveyed, but the conveyance speed v3 of the nonwoven fabric 30 is not always constant as described above. In particular, there may be a problem when the conveyance speed v3 of the nonwoven fabric 3 becomes slower than usual.

  For example, in the heating unit 61, assuming that the amount of hot air per unit time injected into the case member 62 is constant, if the transport speed of the nonwoven fabric 3 is constant, the amount of heat applied to the nonwoven fabric 3 is also It is constant. However, if the conveyance speed of the nonwoven fabric 3 becomes slow, the amount of time for which the nonwoven fabric 3 stays in the spaces SP62a and SP62b in the case member becomes longer, so that an excessive amount of heat is applied to the nonwoven fabric 3.

  When an excessive amount of heat is applied to the nonwoven fabric 3, the nonwoven fabric 3 is softened inside the case member 62, and the nonwoven fabric 3 is easily stretched by being pulled in the transport direction by the action of tension applied in the transport direction. Furthermore, since the hot air flows along the nonwoven fabric 3 in the transport direction, the flow of the hot air acts as a pulling force that pulls the nonwoven fabric 3 in the transport direction, and the nonwoven fabric 3 becomes easier to stretch. When the nonwoven fabric 3 is pulled in the transport direction, the bulk recovered on the surface of the nonwoven fabric 3 tends to be crushed, making it difficult to perform bulk recovery normally. Further, the fact that the nonwoven fabric 3 extends in the conveying direction also means that the dimension in the width direction (CD direction) shrinks, and there is a possibility that the quality as a product cannot be maintained.

  Therefore, in order to perform normal bulk recovery, it is necessary to appropriately adjust the conditions for heating the nonwoven fabric 3 in accordance with fluctuations in the conveyance speed of the nonwoven fabric 3.

  First, as a heating condition, a method for adjusting the amount of hot air blown when the nonwoven fabric 3 is heated will be described. FIG. 4 is a diagram illustrating a control flow for the transport unit 30 when performing the bulk recovery operation of the nonwoven fabric 3 using the bulk recovery device 20. FIG. 5 is a diagram illustrating a control flow for the heating unit 60 when performing the bulk recovery operation of the nonwoven fabric 3 using the bulk recovery device 20.

  When the carrying operation is started, as shown in FIG. 4, first, the control unit 100 controls the carrying operation of the nonwoven fabric 3 by the carrying unit 30 (S301). The conveyance operation control of the nonwoven fabric 3 is performed based on a speed control program stored in the memory of the control unit 100, and the conveyance speed is gradually increased at a predetermined acceleration from the start of operation to the conveyance speed v3 during steady operation.

  In the bulk recovery operation using the bulk recovery device 20, the transport speed v <b> 3 of the nonwoven fabric 3 may be changed at the timing of material joining as described above. The control unit 100 determines whether or not the transport speed v3 needs to be changed (S302). When the transport speed v3 is changed (Yes in S302), the speed command for controlling the transport unit 30 to change the transport speed. A process of changing the value is performed (S303). The change of the speed command value is also managed based on the speed control program stored in the memory of the control unit 100. For example, v3 = 500 (m / min), which is a steady speed at the timing of material splicing, is Speed v3 = 300 (m / min). In the present embodiment, the transport speed v3 is automatically changed by the control unit 100, but the transport speed may be artificially changed from the outside.

  On the other hand, when it is not necessary to change the conveyance speed v3 during the conveyance operation of the nonwoven fabric 3 (No in S302), the control unit 100 continues the conveyance operation as it is without changing the conveyance speed.

  Based on such a flow, the conveyance operation of the nonwoven fabric 3 is continued (S304). And when conveying operation is complete | finished (S304 is Yes), operation | movement of the conveyance part 30 is stopped (S305) and the conveyance operation of the nonwoven fabric 3 is complete | finished. When the conveying operation is continued as it is (S304 is No), the process returns to the step S301 and the conveying operation of the nonwoven fabric 3 is continuously controlled.

  In addition, the control unit 100 controls the hot air supply amount in conjunction with the transport operation control. When the control of the transport operation is started in S301, the control unit 100 reads the speed data of the transport speed v3 as shown in FIG. 5 (S601).

  Then, after the speed data is read, the heating condition is changed based on the transport speed data (S602). Here, the air volume Vh of the hot air is changed as the heating condition. The change in the air volume is, for example, the difference between the wind speed value vw (m / min) of the hot air and the transport speed v3 (m / min) of the nonwoven fabric 3 in each of the outward space SP62a and the return space SP62b inside the case member 62. To be constant. That is, the air volume is controlled so that vw−v3 = K (K is a constant). Specifically, the controller 100 calculates the wind speed value vw (t) (= K + v3 (t)) corresponding to the v3 (t) with reference to the transport speed v3 (t) of the nonwoven fabric 3 at a certain time t, The air volume Vh (t) to be supplied at the wind speed value vw (t) is determined. As described above, the air volume Vh (t) can be calculated by the product of the cross-sectional area of the spaces SP62a and SP62b and the wind speed value vw (t).

  After the air volume is determined, the control unit 100 controls the blower 67b and the heater 67h of the hot air supply device 67 to supply hot air of the air volume Vh (t) to the pressure chambers R63a and R63b of the heating unit 61 (S603). Thereby, hot air is injected so that the wind speed value becomes vw (t) in the spaces SP62a and SP62b inside the case member 62.

  The method for determining the air volume Vh (t) is not limited to such an example. For example, the air volume Vh may be set as a fixed value in advance for each assumed change in the conveyance speed (for example, the conveyance speed at the time of material splicing or the conveyance speed at the time of failure), or the conveyance speed v3 of the nonwoven fabric 3 The air volume Vh may be calculated by multiplying by a predetermined coefficient.

Based on such a flow, the bulk recovery operation of the nonwoven fabric 3 is continued (S604). When the transport operation is finished (S604: Yes), the bulk recovery operation is stopped and the supply of hot air is also stopped (S605). When the bulk recovery operation is continued as it is (S604: No), the process returns to the step S601 and the hot air supply amount is controlled according to the conveyance speed data.
By appropriately adjusting the heating conditions (the volume of hot air) according to the conveyance speed of the nonwoven fabric 3, it is possible to suppress an excessive amount of heat being applied to the nonwoven fabric 3 and realize a normal bulk recovery operation. .

<Modification of heating condition adjustment>
As another example of the method of adjusting the conditions for heating the nonwoven fabric 3, the temperature of hot air may be adjusted in addition to the amount of hot air supplied.

  In the above-described example, the amount of heat applied to the nonwoven fabric 3 per unit time is adjusted by changing the amount of hot air when the conveyance speed of the nonwoven fabric 3 becomes slow (decreasing the amount of hot air supplied). However, when the fluctuation of the conveyance speed is very large, the nonwoven fabric 3 may not be sufficiently suppressed from being heated excessively only by changing the amount of hot air. In such a case, the amount of heat applied to the nonwoven fabric 3 per unit time is increased by changing the temperature of the hot air in addition to changing the amount of hot air supplied (lowering the temperature of the supplied hot air). It is possible to suppress becoming too much.

  FIG. 6 is a diagram illustrating a modification of the control flow for the heating unit 60 when performing the bulk recovery operation of the nonwoven fabric 3. In addition, since the control method of the conveyance part 30 is fundamentally the same as the flow demonstrated in FIG. 4, only the control flow of the heating part 60 is demonstrated here.

  In this modification, the adjustment method of the heating condition is also changed according to the magnitude of the change in the nonwoven fabric conveyance speed v3. First, in the same manner as S601 in FIG. 5, data on the conveyance speed v3 of the nonwoven fabric is read (S611). When a change in the transport speed v3 is detected in the read data, the control unit 100 determines that the change value of the transport speed v3 (here, the change value may be a change amount or a change rate per unit time). It is determined whether or not it is larger than the threshold value Tv1 (S612). This threshold value Tv1 is a value that prescribes a large speed change that requires an urgent measure, and is difficult to cope with by changing the heating conditions when the transport speed of the nonwoven fabric 3 changes. It is required by doing. When the change value of the conveyance speed V3 is larger than the threshold value Tv1 (S612 is No), for example, when the conveyance operation is urgently stopped, there is a possibility that an excessive amount of heat is applied to the nonwoven fabric 3. Is expensive. In this case, the process of S615, which will be described later, is performed because only the process of reducing the supply amount of hot air is not enough.

  On the other hand, when the change value of the conveyance speed v3 is equal to or less than the threshold value Tv1 (Yes in S612), the bulk recovery operation is continued, and the control unit 100 subsequently determines whether or not the conveyance speed v3 is greater than the reference value Tv2. Is determined (S613). The reference value Tv2 is a speed that serves as a reference when determining a method for changing the heating condition, and is obtained by conducting a test or the like in advance. In this modification, when the conveyance speed v3 is equal to or higher than the reference value Tv2 (Yes in S613), the air volume for changing the hot air supply amount (reducing the supply amount) is determined in the same manner as S602 in FIG. (S614). That the conveyance speed v3 is equal to or higher than the reference value Tv2 means that the conveyance speed of a certain speed is maintained. Therefore, it is excessive in the nonwoven fabric 3 only by adjusting the amount of hot air. It is possible to sufficiently suppress the amount of heat applied. On the other hand, when the conveyance speed v3 is smaller than the reference value Tv2 (No in S613), it means that the conveyance speed is low. Therefore, the nonwoven fabric 3 is simply reduced by reducing the amount of hot air supplied. An excessive amount of heat cannot be suppressed. Therefore, the control unit 100 performs a process of changing the temperature of the hot air (lowering the temperature) in addition to changing the air volume of the hot air (S615). The temperature to be changed is determined based on the amount of heat per unit time applied to the nonwoven fabric 3. For example, the air volume is determined in the same manner as S602 in FIG. 5, and the temperature of the hot air is determined so that the heat quantity is smaller than a predetermined magnitude with respect to the air volume. The control unit 100 controls the blower 67b and the like of the hot air supply device 67 to change the amount of hot air, and also controls the heater 67h to change the temperature of the hot air. At this time, if the heaters 67ha and 67hb are arranged close to the case member 62 as indicated by a two-dot chain line in FIG. 3A, the responsiveness of temperature adjustment can be enhanced. In addition, when it is desired to rapidly reduce the temperature, in addition to adjusting the heater 67h (67ha, 67hb), the amount of outside air (gas having a low temperature) taken in from the suction side portion 67bs of the hot air supply device 67 is increased. You may do it. Further, by reducing the reuse rate of the hot air (gas having a high temperature) recovered through the recovery pipe member 69 after being exhausted from the discharge ports 63ha and 63hb of the case member 62, the hot air supply device 67 The temperature of the hot air supplied may be lowered.

  Note that when setting the threshold value Tv1 and the reference value Tv2, a plurality of different values may be set stepwise and compared with the conveyance speed. For example, a first threshold value and a second threshold value higher than the first threshold value are set in S612, and a warning is first issued when the amount of change in the conveyance speed becomes larger than the first threshold value. A flow in which the process of S615 is performed when the threshold value is larger than 2 may be used.

  After the heating condition is changed (S614, S615), the bulk recovery operation is continued according to the changed condition (S616). Thereafter, when the bulk recovery operation is finished (S616 is Yes), the conveying operation and the hot air supply operation are stopped and the bulk recovery operation is finished (S617). When the bulk recovery operation is continued as it is (S616 is No), the process returns to the step S611 and the conveyance speed of the nonwoven fabric 3 is continuously read.

  Further, as another example of a method for adjusting the conditions for heating the nonwoven fabric 3, the feed amount of the nonwoven fabric 3 by the transport unit 30 may be adjusted. In the present embodiment, the control unit 100 controls both the upstream drive conveyance roller 32u and the downstream drive conveyance roller 32d to adjust the tension applied to the nonwoven fabric 3 during conveyance, and the nonwoven fabric 3 is excessively stretched in the conveyance direction. Is suppressed. For example, during the steady operation of the bulk recovery device 20, the ratio R of the peripheral speed value V32u (m / min) of the upstream drive transport roller 32u to the peripheral speed value V32d (m / min) of the downstream drive transport roller 32d (= Each servo motor is controlled so that (V32u / V32d) becomes constant. On the other hand, if the circumferential speed value V32u of the upstream drive conveyance roller 32u is larger than the circumferential speed value V32d of the downstream drive conveyance roller 32d, that is, if R> 1, then the nonwoven fabric 3 Is transported in a state where slackening occurs in the transport direction. Therefore, even when the conveyance speed of the nonwoven fabric 3 is slowed and more heat is applied than necessary, the nonwoven fabric 3 itself is suppressed from extending in the conveyance direction. The control method for adjusting the feed amount of the nonwoven fabric 3 is substantially the same as the flow described in FIG. 4, and the operation of the transport unit 3 is controlled by the control unit 100 in accordance with the change in the transport speed v3 of the nonwoven fabric 3. Thereby, it is suppressed that the recovered bulk on the surface of the nonwoven fabric 3 is crushed.

  In each of the above examples, the control unit 100 not only detects the change in the conveyance speed v3 but also detects the length (dimension) in the width direction (CD direction) of the nonwoven fabric 3, thereby conveying the nonwoven fabric 3 in the conveyance direction. You may make it judge the extent of elongation in. When the nonwoven fabric 3 is stretched in the transport direction, the length in the width direction is reduced by that amount. By detecting the amount of contraction in the width direction, the stretch amount in the transport direction can be estimated.

  When it is desired to detect the length of the nonwoven fabric 3 in the width direction, a width sensor 70 is provided at a position downstream of the heating unit 61 of the heating unit 60 as shown in FIG. FIG. 7 is an explanatory diagram of the width sensor 70. As shown in FIG. 7, as an example of the width sensor 70, a configuration including a light projecting unit 71 that projects light and a light receiving unit 72 that receives light cast from the light projecting unit 71 can be exemplified. The light projecting unit 71 and the light receiving unit 72 are disposed opposite to each other on both sides in the thickness direction of the nonwoven fabric 3. The light receiving unit 72 is, for example, a one-dimensional CCD image sensor in which a plurality of CCD elements are arranged in the CD direction, and the image sensor outputs a signal having a size corresponding to the number of CCD elements that receive light. The number of CCD elements that receive light varies depending on the size of the area shielded by the nonwoven fabric 3. Therefore, information indicating the length in the width direction can be generated from the signal, and the generated information is output to the control unit 100 in real time.

  On the other hand, the target value of the length in the width direction of the nonwoven fabric 3 is recorded in advance in the memory of the control unit 100. And the control part 100 calculates the value of the length of the width direction from the information output from the width sensor 70, compares the calculated length value with the target value as the actual value of the length in the width direction, Based on the information of the comparison result and the conveyance speed of the nonwoven fabric 3, the operations of the conveyance unit 30 and the heating unit 60 are controlled as necessary by the method described above. Thus, the actual influence by the amount of heat applied to the nonwoven fabric 3 can be recognized by estimating the amount of elongation in the conveyance direction from the amount of shrinkage of the width of the nonwoven fabric 3. And it can suppress that excessive calorie | heat amount is added to the nonwoven fabric 3 by changing a heating condition based on the information.

  In S612 of FIG. 6, as an emergency measure in the case where the conveyance speed v3 of the nonwoven fabric 3 is drastically decreased or the conveyance is urgently stopped and the amount of heat applied to the nonwoven fabric 3 cannot be sufficiently reduced, The hot air may be forcibly discharged from the inside of the member 62 to the outside. FIG. 8 is a diagram illustrating an example of a method for forcibly discharging hot air from the inside of the case member 62. In FIG. 8, the wall member (also referred to as the upper end plate) at the upper end in the vertical direction for calibrating the case member 62 and the wall member (also referred to as the lower end plate) at the lower end in the vertical direction are both movable up and down in the vertical direction. To do. Then, when the decrease in the conveyance speed v3 is large, the control unit 100 moves the upper end plate and the lower end plate in the vertical direction as indicated by the white arrows in FIG. The space SP62a for the outward path and the space SP62b for the backward path are opened to the atmosphere. Thereby, since the hot air in space SP62a, SP62b can be discharged | emitted at a stretch in air | atmosphere and heat can be spread | diffused outside, the amount of heat added to the nonwoven fabric 3 can be reduced greatly in a short time.

  === Other Embodiments ===

  As mentioned above, although embodiment of this invention was described, said embodiment is for making an understanding of this invention easy, and is not for limiting and interpreting this invention. Further, the present invention can be changed or improved without departing from the gist thereof, and needless to say, the present invention includes equivalents thereof. For example, the following modifications are possible.

  In the above-described embodiment, the nonwoven fabric 3 for the top sheet 3 of the pet sheet 1 is exemplified as the processing target of the bulk recovery device 20, but the present invention is not limited to this. For example, a non-woven fabric for a top sheet of a sanitary napkin or a non-woven fabric for a top sheet of a diaper may be used. The processing target of the bulk recovery device 20 is not limited to the nonwoven fabric 3 for the top sheet 3. That is, you may process the nonwoven fabric of the material of the other components with which bulkiness is requested | required with the bulk recovery apparatus 20 of this invention.

  In the above-described embodiment, as illustrated in FIG. 1B, as an example of the nonwoven fabric 3 for the top sheet 3, the nonwoven fabric 3 having a plurality of linear protrusions 3 p, 3 p. Not exclusively. For example, a non-woven fabric in a normal form, that is, a non-woven fabric having substantially flat surfaces on both sides may be used.

  In the above-described embodiment, as illustrated in FIG. 2, the heating unit 61 of the heating unit 60 heats the nonwoven fabric 3 in both the outward path and the return path, but is not limited thereto. For example, when the bulk is sufficiently recovered by only one of the forward path and the return path, either the forward path injection port 63Na or the return path injection port 63Nb may be omitted. On the contrary, if the bulk recovery is insufficient with only two passes of the forward pass and the return pass, a plurality of the heating units 61 described above may be provided, and the nonwoven fabric 3 may be heated by 3 passes or more. good. In addition, the direction which provided the injection ports 63Na and 63Nb corresponding to each of an outward path and a return path has the dimension of the longitudinal direction of the heating unit 61, while ensuring the conveyance path length of the nonwoven fabric 3 required for bulk recovery firmly. Since shortening can be achieved, it is preferable.

  In the above-described embodiment, as shown in FIGS. 3A and 3B, the heating unit 61 is configured by a method different from the existing air-through method, but this is not a limitation. That is, you may comprise a heating unit by the existing air through system. In addition, the heating unit comprised by the existing air through system is as follows, for example. The heating unit was provided so as to be opposed to one side of the both surfaces of the nonwoven fabric 3 conveyed along the conveyance direction and the hot air injection port provided opposite to the other surface of the two surfaces. A hot air suction port. Then, by forming a streamline that sucks hot air jetted from the jet port by the suction port by both the jet port and the suction port, the hot air is penetrated in the thickness direction of the nonwoven fabric 3 to heat the nonwoven fabric 3. To do.

  In addition, as a conveyance mechanism which conveys the nonwoven fabric 3 in a conveyance direction, a suction belt conveyor apparatus, a suction drum apparatus, etc. can be illustrated. That is, the suction belt conveyor device places and conveys the nonwoven fabric 3 on the outer peripheral surface of an endless belt that circulates around the drive, and the outer peripheral surface is provided with a plurality of air intake holes. It functions as the suction port for sucking hot air. Further, the suction drum device winds and conveys the nonwoven fabric 3 around the outer peripheral surface of the rotating drum that is driven and rotated, and the outer peripheral surface is provided with a plurality of intake holes. It functions as the above-mentioned suction port for sucking.

  In the above-described embodiment, a solid member that basically does not have a space other than the pressure chambers R63a and R63b is used as the material of the partition wall member 63. However, the material is not limited to this. For example, you may use the hollow member which has space inside for the purpose of weight reduction. As an example of the hollow member, for example, a stainless steel flat plate member (not shown) forming the forward wall 63wa of FIG. 3A, a stainless steel flat member (not shown) forming the return wall 63wb, A combination member having a prismatic member (not shown) inserted between them to connect these flat plate members can be exemplified.

  In the above-described embodiment, one control unit (control unit 100) controls both the operation of the transport unit 30 and the operation of the heating unit 60. However, the present invention is not limited to this. For example, the control unit 100 has a first control unit (Main PLC) and a second control unit (Sub PLC), the first control unit is in charge of controlling the transport unit 30, and the second control unit You may make it take charge of control of the heating part 60. FIG. That is, the first control unit may perform the control described with reference to FIG. 4, and the second control unit may perform the control described with reference to FIG. In this case, the 1st control part and the 2nd control part are connected so that communication is possible, the 2nd control part detects the data of conveyance speed v3 of the nonwoven fabric controlled by the 1st control part, and the data concerned Based on the above, the second control unit changes the heating conditions (conditions such as the volume and temperature of hot air). By sharing the control target, the processing load on each of the first control unit and the second control unit is reduced, and stable control is easily performed.

  In the above-described embodiment, the configuration including the light projecting unit 71 and the light receiving unit 72 is illustrated as an example of the width sensor 70 (FIG. 7), but the configuration is not limited thereto. For example, the dimension in the width direction may be measured by an appropriate camera. That is, at an appropriate control cycle, the edge of the nonwoven fabric 3 in the width direction is imaged by a CCD camera to generate image data of the edge, and the image data is binarized, etc. A position in the CD direction may be obtained, and information related to the dimension in the width direction may be output based on the position.

1 Pet sheet (absorbent article),
3 Top sheet (nonwoven fabric), 3R nonwoven fabric,
3a surface, 3b surface, 3e outer periphery,
3t groove, 3p protrusion, 3h through hole,
3es tip, 3ee tail,
4 Absorber, 4c Absorbent core,
4t1 covering sheet, 4t2 covering sheet,
5 Back sheet, 5e Outer peripheral edge,
20 Bulk recovery device,
30 transport section,
32 transport rollers,
32u upstream drive conveyance roller, 32d downstream drive conveyance roller,
35 feeding device,
36 Material handling equipment,
37 accumulator device,
37m movable roller, G37m movable roller group,
37s fixed roller, G37s fixed roller group,
38 Tension control device,
38dn dancer roll, 38k drive roll, 38s fixed roll,
60 heating units, 61 heating units, 62 case members,
62ain inlet, 62aout outlet (exhaust port),
62-bin inlet, 62-bout outlet (exhaust port),
63 Bulkhead member,
63Na Outlet jet, 63Nb Return jet,
63ha outlet, 63hb outlet,
63wa forward wall, 63wb backward wall,
64 guide rollers,
67 Hot air supply device,
67b blower, 67bs suction side part,
67h heater, 67ha heater, 67hb heater,
67i impeller, 67p pipe member, 67pc pipe member, 69 recovery pipe member,
70 width sensor,
71 Light emitter, 72 Light receiver,
SP62a Outbound space, SP62ae downstream end,
SP62b return path space, SP62be downstream end,
R63a pressure chamber, R63b pressure chamber,
L3 loop, L3dn loop

Claims (8)

An apparatus for recovering the bulk of the nonwoven fabric by blowing and heating hot air on the nonwoven fabric conveyed in the conveying direction,
A transport unit for transporting the nonwoven fabric;
A case member through which the nonwoven fabric to be conveyed enters and exits, and an injection port for injecting the hot air into the space inside the case member, and the injection port on the surface of the nonwoven fabric that is conveyed in the space inside the case member A heating unit for blowing and heating the hot air from,
While controlling the conveyance speed of the nonwoven fabric conveyed by the conveyance unit, the control unit changes the conditions when heating the nonwoven fabric according to the conveyance speed of the nonwoven fabric,
A bulk recovery device for a nonwoven fabric, comprising: It is a bulk recovery apparatus of the nonwoven fabric according to claim 1,
A hot air supply unit for supplying the hot air to the heating unit;
The said control part changes the air volume of the said hot air supplied to the said heating part according to the conveyance speed of the said nonwoven fabric, The bulk recovery apparatus of the nonwoven fabric characterized by the above-mentioned. The bulk recovery apparatus for nonwoven fabric according to claim 1 or 2,
The said control part changes the temperature of the said hot air supplied to the said heating part according to the conveyance speed of the said nonwoven fabric, The bulk recovery apparatus of the nonwoven fabric characterized by the above-mentioned. A bulk recovery device for a nonwoven fabric according to any one of claims 1 to 3,
The transport unit has two drive rollers that are driven and rotated to transport the non-woven fabric to positions on both sides in the transport direction of the heating unit in a transport path through which the non-woven fabric is transported,
The said control part changes the circumferential speed value of the drive roller located in an upstream among the said 2 drive rollers according to the conveyance speed of the said nonwoven fabric, The bulk recovery apparatus of the nonwoven fabric characterized by the above-mentioned. A bulk recovery device for a nonwoven fabric according to any one of claims 1 to 4,
A width sensor that outputs information related to the widthwise dimension by measuring the widthwise dimension of the nonwoven fabric at a position downstream of the heating unit in the transport direction;
The said control part changes the conditions at the time of heating the said nonwoven fabric based on the said information output from the conveyance speed and the said width sensor of the said nonwoven fabric, The bulk recovery apparatus of the nonwoven fabric characterized by the above-mentioned. A bulk recovery apparatus for a nonwoven fabric according to any one of claims 1 to 5,
A part of the wall surface constituting the case member is movable so as to open a space inside the case member to the atmosphere,
When the conveyance speed of the nonwoven fabric becomes slower than a predetermined speed, the control unit moves a part of the wall surface and discharges the hot air from the space inside the case member. Non-woven fabric bulk recovery device. It is a bulk recovery apparatus of the nonwoven fabric in any one of Claims 1-6,
An opening when the nonwoven fabric is conveyed is provided in an opening on one end side in the conveyance direction of the case member, and an opening when the nonwoven fabric is conveyed in an opening on the other end side in the conveyance direction of the case member. There is an exit,
The injection port is provided in the inlet side portion of the case member;
The bulk air recovery of the nonwoven fabric, wherein the hot air sprayed from the ejection port flows from the upstream side in the transport direction to the downstream side in the transport direction while contacting one surface of both surfaces of the nonwoven fabric apparatus. A method for recovering the bulk of the non-woven fabric by blowing and heating hot air on the non-woven fabric conveyed in the conveying direction,
Conveying the non-woven fabric;
The non-woven fabric conveyed in the space inside the case member using a heating member provided with a case member through which the non-woven fabric is conveyed and a jet port for injecting the hot air into the space inside the case member. A step of blowing the hot air on the surface from the injection port and heating,
Changing the conditions for heating the nonwoven fabric according to the conveyance speed of the nonwoven fabric,
A method for recovering the bulk of a non-woven fabric, comprising:

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