Patent Grant
9034131
The present invention relates to a technique for arranging aggregate groups of granular particles on an air-permeable carrier web in a predetermined pattern.
Disposable worn articles, such as disposable diapers or pants or feminine sanitary supplies, have an absorbent body thereon for absorbing body fluid. Such an absorbent body has a sandwich structure including an absorbent core between two webs.
It has recently been proposed to use only a powdery absorbent polymer as an absorbent core, without using a fluff pulp (First Patent Document). In this case, a large number of aggregate groups of granular particles are arranged while being separated from one another lengthwise and crosswise, and two webs are sealed (attached) together along the gaps between the aggregate groups, thereby holding the arrangement pattern of the aggregate groups.
However, if granular particles remain in areas where the carrier web and the cover web are sealed together with granular particles arranged therebetween in a predetermined pattern, the attachment between the webs interposing granular particles therebetween can more easily come off.
In such a case, when attaching the webs together, granular particles may get caught in the sealer device, resulting in a seal failure.
It is therefore an object of the present invention to provide a method and an apparatus for arranging granular particles, whereby aggregate groups of granular particles can be arranged in a predetermined pattern while preventing some granular particles from moving out of predetermined areas.
In order to achieve the object set forth above, a method of the present invention is a method for arranging a plurality of granular particles in each of a plurality of arrangement areas which are partitioned from one another in a predetermined pattern, the method including the steps of carrying an air-permeable carrier web along a predetermined carrying path while holding a first surface of the carrier web on a carrying surface of a carrier device; dispensing the granular particles onto a second surface, opposite to the first surface, of the carrier web being carried; drawing a first air from a plurality of suction holes formed in the carrying surface through the carrier web, thereby holding some of the plurality of granular particles on each suction area on the second surface of the carrier web corresponding to one of the suction holes; and giving at least a part of the first air a flow component flowing in a direction along the second surface of the carrier web by means of an airflow deflector opposing the second surface of the carrier web, thereby moving some other ones of the plurality of granular particles on a non-suction area on the carrier web between one of the plurality of suction holes and another toward at least one of the suction areas, thus arranging the granular particles in each of the arrangement areas in the predetermined pattern on the carrier web.
On the other hand, the present apparatus includes: a carrier device for carrying an air-permeable carrier web along a predetermined carrying path while holding a first surface of the carrier web on a carrying surface thereof;
a dispenser device for dispensing granular particles onto a second surface, opposite to the first surface, of the carrier web being carried; a sucker (drawing) device including a plurality of suction holes formed in the carrying surface for drawing a first air into the suction holes through the carrier web, thereby holding some of the plurality of granular particles on each suction area on the second surface of the carrier web corresponding to one of the suction holes; and an airflow deflector opposing the second surface of the carrier web for giving at least a part of the first air a flow component flowing in a direction along the second surface of the carrier web.
The first air is drawn into the plurality of suction holes formed in the carrying surface through the carrier web, thereby holding some of the granular particles on the carrier web in accordance with the pattern, while leaving the other granular particles in the non-suction area.
The airflow deflector, opposing the second surface of the carrier web, inhibits the flow of the first air in the normal direction perpendicular to the second surface. Therefore, a part of the first air is given a flow component flowing in the direction along the second surface. The flow component causes the other granular particles in the non-suction area on the carrier web to move toward the suction areas along the second surface of the carrier web. Thus, the aggregate groups of granular particles are arranged in the predetermined pattern, and it is possible to prevent granular particles from moving out of the suction areas.
In a preferred embodiment of the present method, the method further includes the steps of after the step of arranging the granular particles in the predetermined pattern, covering the second surface of the carrier web and the granular particles by a cover web, thereby producing a sandwich structure; and attaching the carrier web and the cover web together over the non-suction area in order to prevent the granular particles in the arrangement areas arranged in the predetermined pattern from moving from one of the plurality of arrangement areas to another.
On the other hand, in a preferred embodiment of the present apparatus, the apparatus further includes: a guide (introduce) device for guiding (introducing) the cover web onto the carrying path, downstream of the airflow deflector along the carrying path of the carrier web, in order to produce a sandwich structure in which the second surface of the carrier web and the granular particles are covered by a cover web; and an attachment device for attaching the carrier web and the cover web together over a non-suction area between one of the plurality of suction holes and another in order to prevent the granular particles in the arrangement areas arranged in the predetermined pattern from moving from one of the plurality of arrangement areas to another.
In these cases, some of the granular particles arranged in the predetermined pattern are unlikely to move out onto the non-suction area, and will not be interposed between the carrier web and the cover web in the non-suction area. Thus, a failure is unlikely to occur in the seal between the webs, and it is possible to prevent the webs from peeling off of each other in the sealed portions.
While the attachment in the present method may be done by using an adhesive, as well as welding, in a more preferred embodiment of the present method, the attachment step is performed by welding the webs together.
While the attachment in the present apparatus may be done by using an adhesive, as well as welding, in a more preferred embodiment of the present apparatus, the attachment device is a welder device for welding the webs together.
Where the webs are attached together using an adhesive, the webs can be attached together even if a slight amount of granular particles is left in the non-suction area between the webs; however, where the webs are welded together, granular particles, which is a foreign matter, being left in the non-suction area will significantly lower the reliability of the attachment.
Therefore, where the webs are attached together by welding, advantageous effects of the present method will be more pronounced.
In a more preferred embodiment of the present method, in the step of arranging while drawing the first air, a second air is discharged from a second air discharge hole open in a portion of the carrying surface corresponding to the non-suction area toward the second surface of the carrier web, whereby granular particles on the non-suction area are blown away by the second air having passed through the carrier web via the second surface, thus arranging the granular particles in the predetermined pattern on the carrier web.
On the other hand, in a more preferred embodiment of the present apparatus, the apparatus further includes a discharger device including a second air discharge hole open in a portion of the carrying surface corresponding to the non-suction area for discharging the second air from the discharge hole toward the second surface of the carrier web, while the first air is being drawn, whereby granular particles on a portion corresponding to the non-suction area are blown away by the second air having passed through the carrier web via the second surface.
In these cases, the second air passes through the carrier web to blow away granular particles in the non-suction area of the carrier web. The blown granular particles are drawn onto suction areas on the carrier web corresponding to the suction holes, thus arranging the granular particles in a predetermined pattern on the carrier web.
The present invention will be understood more clearly from the following description of preferred embodiments taken in conjunction with the accompanying drawings. Note however that the embodiments and the drawings are merely illustrative and should not be taken to define the scope of the present invention. The scope of the present invention shall be defined only by the appended claims. In the accompanying drawings, like reference numerals denote like components throughout the plurality of figures.
Embodiment 1 of the present invention will now be described with reference to the drawings.
Worn Article 100:
As shown in
The crotch portion 203 is continuous with the front portion 201 and the back portion 202, and extends in the longitudinal direction Y perpendicular to the girth direction X. The front girth portion 301 and the back girth portion 302 may be attached together when worn, or may be attached together in advance before being worn.
The absorbent body 200 may be provided with three-dimensional gathers (not shown).
The absorbent body 200 may be formed with around-the-leg portions narrowed along the legs of the wearer.
Moreover, an elastic member for fitting the worn article 100 to the wearer may be provided in portions of the absorbent body 200 which are to be present around the legs. The elastic member may be, for example, a plurality of rubber threads or rubber tapes, a film, or a material including a thermoplastic resin, or the like. These materials may be provided on the front portion 201 and the back portion 202 as elastic members for fitting the worn article 100 to the wearer.
As shown in
Note that in various figures, welded portions are denoted by “xx”.
The top sheet 21 and the cover sheet 22 of
The core 23 is comprised of a large number of absorbent granular particles 3. Such granular particles 3 are made of an absorbent high molecular polymer well known in the art, wherein the granular particles 3 have an average particle size of about 10 μm to about 1,000 μm prior to absorbing water, and swell after absorbing water to a volume that is several times or hundreds of times larger.
Note that in various figures, the granular particles 3 are denoted by a large number of dots.
The core 23 is formed by aggregate groups 30 each being a collection of a larger number of the granular particles 3, with the aggregate groups 30 being arranged in a large number of arrangement areas D. The aggregate groups 30 and 30 are laid out separately in arrangement areas D and D which are partitioned from one another by lattice-patterned welded lines L and L extending lengthwise and crosswise. That is, arrangement areas D and D in which the aggregate groups 30 and 30 are arranged are partitioned from one another by the welded lines L and L.
In other words, each aggregate group 30 is composed of a collection of a large number of granular particles 3, and one of the aggregate groups 30 and another group thereof are arranged with respect to each other in the lengthwise or crosswise direction with the welded line L, L therebetween, as shown in
As shown in the figure, the arrangement area D denoted by a two-dot-chain line is often defined slightly larger than a suction area 1B onto which a plurality of granular particles 3 are drawn by suction.
That is, as shown in the figure, the areas of the arrangement area D and the suction area 1B are often defined so that there is a slight clearance between the welded line L surrounding the arrangement area D and the perimeter of the suction area 1B. That is, the suction area 1B is often contained within the arrangement area D.
In such a case, there is a space provided between the welded line L and the suction area 1B.
Therefore, if some of a plurality of granular particles 3 arranged on the suction area 1B move out of the area of the suction area 1B, the out-of-place granular particles 3 will be placed in the space between the suction area 1B and the welded line L, preventing some of the granular particles from moving out to reach the welded line L.
Note that the arrangement area D and the suction area 1B may be defined as areas of the same size.
As shown in
Each welded line L does not need to be completely continuous, but the welded portions may be formed intermittently to such a degree that it is difficult for granular particles 3 of each aggregate group 30 to move out into other aggregate groups 30.
That is, the welded lines L and L may be formed to such a degree that granular particles 3 in one of the aggregate groups 30 arranged in a predetermined pattern are prevented from moving out into another aggregate group.
The arrangement of the aggregate groups 30 may be of any predetermined pattern, and the aggregate groups 30 do not need to be regularly arranged in the lengthwise and crosswise directions. The number of granular particles 3 to be contained within an aggregate group 30 does not need to be generally equal to those of other aggregate groups 30, and there may be a distribution among the aggregate groups 30 in accordance with that of the amount of body fluid to be discharged.
As shown in the enlarged view of
Next, an apparatus for manufacturing the absorbent body 200, i.e., an arrangement apparatus, will be described with reference to
The present arrangement apparatus includes a dispenser device 5, an airflow deflector 6, first, second and third guide rollers 71, 72 and 73 and an ultrasonic horn (an example of an attachment device) 81 around a carrying drum (an example of a carrier device) 4.
The first, second and third guide rollers 71, 72 and 73 are rollers for guiding a carrier web 1, a cover web 2 and a film 9 onto the outer periphery of the drum 4, respectively.
As shown in
The first surface 11 of
The dispenser device 5 of
As shown in
As shown in
Each discharge hole 42 communicates with a positive pressure source (not shown) and discharges the second air α2 from the discharge hole 42 toward the second surface 12 of the carrier web 1, so that the granular particles 3 are blown away off a non-suction area 1A of the carrier web 1 by the second air α2 having passed through the carrier web 1 via the second surface 12. The discharge holes 42 and the positive pressure source together form a discharger device.
The airflow deflector 6 is, for example, a punching plate having a large number of through holes 60 therein, and the airflow deflector 6 is curved in conformity to the carrying surface 41 of the carrying drum 4 of
Note that the airflow deflector 6 is secured to a frame supporting the drum 4, and has a relative velocity in the circumferential direction R with respect to the drum 4 rotating in the circumferential direction R.
The second guide roller 72 of
The third guide roller 73 of
The ultrasonic horn 81 gives a vibratory energy to the webs 1 and 2, in cooperation with an anvil (not shown) formed on the carrying surface 41 of the carrying drum 4, downstream of the third guide roller 73 along the carrying path of the carrier web 1. Thus, the carrier web 1 and the cover web 2 are welded together in the non-suction areas 1A of
With welding (sealing) using ultrasonic vibrations, a mechanical vibration is transferred to the horn 81 of
Next, a method for producing the sandwich structure 20 (
As shown in
Between the first guide roller 71 and the airflow deflector 6, the granular particles 3 are dispensed from the dispenser device 5 onto the second surface 12 opposite to the first surface 11 of the carrier web 1 of
The layer of granular particles 3 may be dispensed in intermittent shots for different absorbent bodies 200 (
The layer of granular particles 3 may have a greater thickness at the center of the carrying drum 4 in the axial direction thereof than at opposite ends thereof. The layer of granular particles 3 may have a smaller thickness along the perimeter of each absorbent body 200 (
Referring to
With the suction of the first air α1 and the discharge of the second air α2 simultaneously, the granular particles 3 on the non-suction area 1A are blown away by the second air α2 having passed through the carrier web 1 via the second surface 12, and the blown granular particles 3 are drawn by the first air α1 toward the suction area 1B above the suction hole 40.
As shown in
That is, a part of the flow of the first air α1 is blocked by a solid portion 61 of the airflow deflector 6 so as to include components αr and αs (
Thus, with the suction of the first air α1 and the discharge of the second air α2 simultaneously, the carrying surface 41 holding the granular particles 3 thereon continues to rotate while opposing the airflow deflector 6, while at least a part of the first air α1 is given flow components αr and αs (
That is, some granular particles 3 in non-suction areas 1A move toward other granular particles 3 being held by suction in suction areas 1B.
As a result, as shown in
After the granular particles 3 are arranged on the carrier web 1 in a predetermined pattern, the carrying surface 41 moves away from the airflow deflector 6, and the second surface 12 of the carrier web 1 and the granular particles 3 are covered by the cover web 2 guided by the second guide roller 72 and the film 9 (
Then, when the sandwich structure 20 continues to be rotated by the carrying surface 41 to reach the ultrasonic horn 81 of
Although the cover web 2 of
Then, the sandwich structure 20 is cut into unit pieces of individual worn articles, i.e., unit pieces of individual absorbent bodies 200 of
As shown in these figures, discharge holes are not provided in the non-suction areas 4A in the present embodiment. Also in this embodiment, as in the above example of
In Embodiment 2, the method by which the granular particles 3 are arranged on the suction areas 1B of the carrier web 1 is substantially the same as that of Embodiment 1, and will not be described below. In Embodiment 2, as opposed to Embodiment 1 of
Note that in Embodiment 2, the density with which the suction holes 40 are provided may be increased with respect to that of Embodiment 1.
Otherwise, the configuration is substantially the same as that of Embodiment 1, and like elements will be denoted by like reference numerals and will not be further described below.
The shape of the aggregate group 30 (arrangement area D) of the granular particles 3 in the arrangement pattern may be rectangular as shown in
The seal pattern for partitioning the aggregate groups 30 (arrangement areas D) of the granular particles 3 from one another may be continuous lines as shown in
As shown in
In the present invention, solid portions 61 between air passage portions 60, such as slits as shown in
Therefore, the solid portions 61 are preferably plate-shaped or rod-shaped, instead of being thread-shaped or line-shaped.
The airflow deflector 6 may have a length of some cm to 20 cm or more in the circumferential direction R, e.g., a length of 20 cm or more or 40 cm or more.
The distance between the airflow deflector 6 and the carrying surface 41 is normally set to be about 1 mm to about 10 mm, preferably 2 mm to 8 mm, and most preferably about 3 mm to about 6 mm.
As shown in
As shown in
That is, the airflow deflector 6 preferably has the air passage portions 60 such as through holes both in the circumferential direction R and in the axial direction S between solid portions 61 which inhibit the flow of the first air α1 in the normal direction Z.
While preferred embodiments have been described above with reference to the drawings, obvious variations and modifications will readily occur to those skilled in the art upon reading the present specification.
For example, the carrier device may be a conveyer, instead of a drum.
The method of attachment between the carrier web 1 and the cover web 2 may be an attachment method using thermal welding such as heat seal, for example, instead of ultrasonic welding.
As used in the present invention, “a plurality of granular particles” is a concept including cases where a powdery material is mixed with a plurality of granular particles, as well as cases where they are made only of an aggregate or aggregates of a granular material.
Thus, such changes and modifications are deemed to fall within the scope of the present invention, which is defined by the appended claims.
The present invention is applicable to cases where granular particles are arranged in a predetermined pattern in addition to an absorbent body of a disposable worn article.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2011-027130 | Feb 2011 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2012/052371 | 2/2/2012 | WO | 00 | 6/28/2013 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2012/108330 | 8/16/2012 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 7524449 | Walsh et al. | Apr 2009 | B2 |
| 20020095127 | Fish et al. | Jul 2002 | A1 |
| 20060021695 | Blessing et al. | Feb 2006 | A1 |
| 20070246147 | Venturino et al. | Oct 2007 | A1 |
| 20100114049 | Noda et al. | May 2010 | A1 |
| Number | Date | Country |
|---|---|---|
| 2004-000830 | Jan 2004 | JP |
| 2007-130818 | May 2007 | JP |
| 2008-507384 | Mar 2008 | JP |
| 2008-237381 | Oct 2008 | JP |
| WO 2006015138 | Feb 2006 | WO |
| Entry |
|---|
| International Search Report for corresponding International Application No. PCT/JP2012/052371 mailed May 1, 2012. |
| Number | Date | Country | |
|---|---|---|---|
| 20130284362 A1 | Oct 2013 | US |
