1. Field of the Invention
The present invention relates to a method and apparatus for producing a disposable wearing article such as paper diapers and pants.
2. Description of the Related Art
In the above-mentioned type of wearing articles, in order to form, for example, a waist gathering, an elastic member is placed on a sheet surface. However, such an elastic member allows an absorber to shrink, so that the absorber becomes stiff, degrading a feeling of wearing.
As a prior art of cutting an elastic member, Japanese Laid-Open Patent Publication No. 2001-224627 discloses a method for interposing a film sheet for gathering between a peripheral surface of an adsorbent roller and a cutter blade of a cutter roller, and cutting the film sheet.
Furthermore, International publication No. WO 00/04855 discloses a method for forming a web loop.
In order to achieve the above-mentioned object, a method for producing a wearing article of the present invention includes the steps of: supplying an elastic member; stretching the elastic member; placing the stretched elastic member so that the elastic member spreads across a plurality of first webs divided in a transport direction; making a part of a second web loose in the transport direction while transporting the second web, thereby forming a loose portion; placing the first webs, on which the elastic member is disposed, on non-loose portions before and after the loose portion of the second web; and cutting the elastic member between adjacent first webs of the plurality of first webs.
According to the present invention, the loose portion formed in the second web may be folded into two to form a folded portion. Furthermore, after the first webs are placed, and before and/or after the elastic member is cut, the loose portion of the second web is stretched so as to position the first webs away from each other.
According to the present invention, a method for folding the second web may include the steps of: using a rotation apparatus provided with a plurality of pads which are rotated to continuously transport the second web, thereby supplying the second web to surfaces of the pads with a predetermined interval; allowing the pads to hold the second web on the surfaces of the pads; changing the interval between the adjacent pads supplied with the second web; folding a part of the second web by decreasing the interval between the adjacent pads to make the second web between the adjacent pads loose; and releasing the second web from the pads.
A production apparatus for realizing the production method according to the present invention may includes: a roller for supplying a plurality of first webs divided in a transport direction at a predetermined position in a state where an elastic member is placed so as to spread across the first webs; a rotation apparatus including a plurality of pads which are rotated to continuously transport a second web and approach the roller at the predetermined position; and a cutter for cutting the elastic member. In this apparatus, the respective pads of the rotation apparatus have varying circumferential velocities, the respective pads of the rotation apparatus receive the second web at a receiving position upstream from the predetermined position, and after receiving, an interval between the adjacent pads is decreased while the pads are rotated to the predetermined position, whereby a loose portion is formed in the second web, the first webs are placed to be stacked on a surface of the second web on a basis of the pads at the predetermined position, an interval between the adjacent pads is increased while the respective pads of the rotation apparatus are rotated from the predetermined position to a releasing position downstream from the predetermined position, and the cutter cuts the elastic member in the loose portion while the pads are rotated from the predetermined position to the releasing position.
Another method for folding a web may include the steps of: using a rotation apparatus provided with a plurality of pads which are rotated around a predetermined center axis to continuously transport the web, thereby supplying the web to the surfaces of the pads of the rotation apparatus; rotating the adjacent pads supplied with the web at different velocities to change an interval between the pads, thereby making the web between the pads loose; folding the loose web between the adjacent pads; and releasing the web from the pads.
As the rotation apparatus, for example, a rotation apparatus described in U.S. patent application Ser. No. 09/889,275 may be used. A rotation apparatus disclosed in U.S. Patent Application Publication No. US2002/0103468 may also be used. The disclosures of these are incorporated herein by reference.
According to the present invention, an absorber may be placed between a plurality of first webs with the elastic member cut therebetween. In this case, a shrinking force does not act on an absorber, so that the absorber does not become stiff.
As the elastic member in the present invention, a material containing thread rubber, flat rubber, mesh-shaped rubber, a film, or a thermoplastic elastic member may be adopted. As a material containing a thermoplastic elastic member, hot-melt resin is considered. Furthermore, a plurality of holes or slits may be formed in a film.
According to the present invention, the elastic member may be cut with a light cutter. The light cutter may cut the elastic member by irradiating the elastic member between the plurality of first webs with infrared rays and UV-rays. Furthermore, the elastic member may be cut with an ultrasonic wave.
The wearing article may include products or semi-finished products of a wearing article such as disposable diapers, disposable pants, bandages or the like. The wearing article may further include a single body and a stack of sheets such as fabric, non-woven fabric, a liquid-transparent sheet, or a non-liquid-transparent sheet.
Another production method of the present invention may include the steps of: continuously receiving a stacked web on each pad of a decelerating drum in a state where the web is stretched in a flow direction; after receiving the web, decreasing a circumferential velocity of the respective pads that have received the web so as to make an interval between the respective pads narrow, thereby forming a shrunk portion where the web shrinks between the pads, and holding an edge of the web on the respective pads to keep a state where the held edge is stretched; receiving the web onto a main drum from the decelerating drum in a mixed state where the stretched edge and the shrunk portion are present alternately, and transporting the web while keeping the mixed state; and pressing and heating a part or an entire of the edge by a pressing and heating member on the main drum.
The heat capacity of the stretched edge of the web is small. Therefore, a transport velocity of the web is increased by heating the edge, whereby a transport amount per unit time can be increased. In other words, a heating time for heating the edge can be prolonged in accordance with a ratio at which the edge of the web is stretched. Therefore, even when the transport velocity of the web is large, heat-sealing can be conducted exactly.
These and other advantages of the present invention will become apparent to those skilled in the art upon reading and understanding the following detailed description with reference to the accompanying figures.
Hereinafter, the present invention will be described by way of illustrative embodiments with reference to the drawings.
Embodiment 1
FIGS. 1 to 5A–B show Embodiment 1.
An apparatus for producing a wearing article shown in FIG. 1 is capable of providing a web with looseness and intermittently placing an elastic member on at least a part of the web. For example, the apparatus for producing a wearing article includes a rotation apparatus 1 capable of providing a second web W2 with looseness and a second roller 12 capable of placing an elastic member F on portions of the second web W2 other than those which are loose. When the elastic member F extending across a loose portion of the second web W2 is cut with at least one of a laser, an industrial light, a blade, and scissors, the apparatus can intermittently place the elastic member F on the second web W2. This intermittent placement is mainly caused by the looseness of the second web W2. Hereinafter, the configuration and operation of the rotation apparatus 1, the second roller 12, and the like will be described.
In
The second roller 12 is supplied with a first web W1. The second roller 12 transports the first web W1 while sucking the first web W1 by vacuum suction or the like. On the surface of the second roller 12, for example, a number of suction holes 12a for sucking the first web W1 may be provided. After the first web W1 is sucked to be held on the surface of the second roller 12 by vacuum suction or the like, the first web W1 is divided into a predetermined size with a web cutter 2. In this division, the first web W1 may be cut or half-cut to a predetermined length in a transport direction. In the case where the first web W1 is half-cut, the first web W1 may be cut to a predetermined length together with the elastic member F in a subsequent step or cut in a predetermined length when an interval of pads is increased. After this division, the elastic member F is placed so as to spread across the surface of the respective first webs W1. In the case where the elastic member F is made of thread rubber or flat rubber, an adhesive is applied to at least one of the elastic member F, the first web W1, and the second web.
It may also be possible that after the elastic member F is placed on the first web W1, the elastic member F is cut together with the first web W1. Furthermore, in the case where the elastic member F is made of hot-melt resin, molten resin discharged from the supply apparatus 3 is cooled by the first roller 11. The molten resin may be cooled with cool water. Furthermore, the first roller 11 may be a porous roller. In the case where the first roller 11 is a porous roller, the first roller 11 may be configured so that air is discharged from the inside of the first roller 11 through holes. Due to the air, the hot-melt resin becomes unlikely to adhere to the roller. When the air is discharged from the porous body, the volume of the air is increased to cool the roller. Thus, the hot-melt resin can be cooled. The porous roller may be formed by sintering stainless ball or the like.
Furthermore, it may also be possible that the first roller 11 is be provided with grooves or the like, whereby resin is molded. For example, mesh-shaped (for example, lattice-shaped) grooves are formed on the first roller 11, and hot-melt resin is applied to the grooves of the first roller 11 with a coater or the like, whereby a mesh-shaped elastic member is formed.
When hot-melt resin having a softening point lower than that of Lycra® is used as the elastic member, the subsequent cutting step becomes easier, compared with the case of using Lycra®.
The rotation apparatus 1 for folding is placed in the vicinity of the second roller 12. The rotation apparatus 1 has a plurality of pads 9 capable of sucking the second web W2 and transporting it. On the surface of a pad 9i, suction holes 10 for sucking the second web W2 are provided. The rotation apparatus 1 continuously transports the second web W2, and is in contact with the surface of the second roller 12 via the first web W1, the elastic member F, and the second web W2 at a contact point 0 (predetermined position). Thereafter, the following may also be possible: an additional roller and the pad 9i sandwich the first web W1, the elastic member F, and the second web W2 placed on the pad 9i, whereby the contact therebetween is enhanced.
The elastic member F is cut after being interposed between the first web W1 and the second web W2. The elastic member F is fixed between the webs W1 and W2, so that the elastic member F shrinks less, compared with the case where the elastic member F is placed on one web.
The rotation apparatus 1 receives the second web W2 at a circumferential velocity V11 at a receiving position RP. At a point “A” where the pad 9i receives the second web W2, the circumferential velocity of the pad is V11.
Each pad 9i of the rotation apparatus 1 is rotated at the receiving position RP at the circumferential velocity V11, and decelerates to a circumferential velocity V21 before reaching the contact point 0 (where the distance between the pad 9i and the pad 9i+1 becomes minimum). Therefore, the interval between the pad 9i and the pad 9i+1 becomes narrow before the pad 9i moves from the receiving position RP to the contact point 0. This causes the second web W2 to become loose between the pad 9i and the pad 9i+1, whereby a loose portion Wa is formed.
The pad 9i comes into contact with the second roller 12 via the second web W2 and the like at the circumferential velocity V21 (V11>V21) at the contact point 0 shown in
The circumferential velocity of the pad 9i+1 becomes V31 at a point B where the pad 9i+1 releases the second web W2.
When or after the circumferential velocity of the pad 9i becomes maximum in the vicinity of the point A in
It is preferable that the apparatus is provided with a directing part so that the loose portion Wa in
The directing part may be, for example, a mechanism for jetting air or a mechanism for pushing the loose portion Wa of the web toward the center of the rotation apparatus 1. Alternatively, the directing part may be a mechanism for sucking the web W toward the center of the rotation apparatus 1 by vacuum suction. In the case where the directing part is a mechanism for jetting air, one or a plurality of directing parts may be provided. Furthermore, in the case where the directing part is a mechanism for pushing the loose portion Wa, one or a plurality of directing parts may be provided. By providing a plurality of directing parts, the loose portion Wa can be bent exactly toward the center of the rotation apparatus 1. In the present embodiment, the loose portion Wa may have a shape dented toward the center of the rotation apparatus 1 due to the weight of the second web W2.
Next, a folding operation will be described. When the second web W2 is sucked to be held on the surface of the pad 9i at the receiving position RP, the second web W2 is transported along the pad 9i of the rotation apparatus 1. When the pad 91 is rotated from the receiving position RP to the contact point 0, the interval between the pads 9i is decreased. Because of this, the loose portion Wa is formed in the second web W2. Furthermore, the loose portion Wa is folded into two to form a folded portion Wb.
The rotation apparatus for conducting the above-mentioned “folding” is not limited to the rotation apparatus 1. For example, an apparatus described in Japanese Patent Application No. 2001-545183 A may be used. The present invention is intended to place an elastic member intermittently on a web. Therefore, the second web W2 is not necessarily folded completely. Furthermore, depending upon the shape of the pad 9i, the second web W2 may have a loop shape.
The folded second web W2 is attached to be stacked on the first web W1 at non-folded portions Wc before and after the folded portion Wb. That is, the elastic member F is not cut until the elastic member F is placed and fixed between the first web W1 and the second web W2. Therefore, the stretched elastic member F hardly shrinks on the second web W2. When the second web W2 is stacked on the first web W1, the first web W1 is not placed on the folded portion Wb folded between the pads 9i and 9i+1 adjacent to each other in the vicinity of the contact point 0. When the interval between the pads 9i and 9i+1 is increased as shown in
As shown in
The exposed elastic member F in
Hereinafter, an example of cutting the elastic member F with a cutter will be described.
The rotation apparatus 1 may be provided with scissors instead of the cutting machine. After the second web W2 is stacked on the first web W1, and the interval between the pad 9i and the pad 9i+1 is slightly increased, the scissors may enter between the pad 9i and the pad 9i+1 to cut the elastic member stretched between the pad 9i and the pad 9i+1. The scissors may enter between the pad 9i and the pad 9i+1 in accordance with the rotation of at least one of the pad 9i and the pad 9i+1. In order for the scissors to perform such an operation, at least one of a cam mechanism and a link mechanism may be used.
In
Herein, during α from the releasing position SP to the receiving position RP, suction through the suction holes 10 may be stopped, and air may be discharged through the suction holes 10. The purpose of this is to smoothly transfer the stack N1 in a downstream direction.
As shown in
A portion represented by a solid line in
Furthermore, the following may also be possible: when the elastic member F is cut so that a trim is not generated as shown in
Embodiment 2
Next, Embodiment 2 will be described. A production apparatus shown in
(1) Arrangement State of Elastic Members:
First, as shown in
The present apparatus includes a first roller 11 for placing a first elastic member 1 for a waist gathering and a guide unit 23 for placing a second elastic member 2 for a leg gathering. The guide unit 23 is capable of arranging the second elastic member F2 for a leg gathering in a curved shape or a linear shape by being reciprocated in the axis direction of a second roller 12 with, for example, a cam or a servo motor. U.S. patent application Ser. No. 10/095,959 discloses an example of the guide unit 23. The second elastic member F2 may be cut mechanically with scissors, a blade, or the like provided at the roller.
After being interposed and fixed between the first and second webs W1 and W2, the first and second elastic members F1 and F2 are cut to be arranged as shown in
In some disposable wearing articles, an elastic member for a leg gathering is placed on a crotch portion. Therefore, such a portion contrasts to cause an unsatisfactory feeling during wearing. In order to avoid this, the elastic member on the crotch portion is cut so as to shrink, whereby the elastic member on the crotch portion can be made short to some degree. However, it is impossible to completely eliminate the elastic member on the crotch portion, so that an unsatisfactory feeling may still remain.
In contrast, when the second elastic member F2 for a leg gathering is placed as shown in
For example, as shown in
Furthermore, as shown in
The adhesive only needs to be applied to a portion where the second elastic member F2 is placed. As a coating method, an adhesive may be applied in an annual shape to at least one of the first and second webs W1 and W2 with a coater or the like. Furthermore, guns with a plurality of valves are placed in a direction across the first web W1 so that opening/closing of the valve may be controlled by the flow speed of at least one of the first web W1 and the second web W2 and the coating shape. In the case of using such guns, an adhesive can be applied in arbitrary regions partitioned in a matrix.
(2) Attachment State of an Absorber:
An absorber C is arranged and attached to the webs W1 and W2 in the above-mentioned arrangement state of the elastic members by a turn apparatus 30. Thereafter, a third elastic member F3 for a waist gathering is placed to form an attachment state of an absorber as shown in
The turn apparatus 30 is provided with a plurality of suction pads 30p around a drum (not shown). The suction pads 30p are rotated in an arrow direction while changing the posture of the absorber C by 90° by turning. As the turn apparatus 30, for example, an apparatus as disclosed by International Publication No. WO 01/44086 or U.S. patent application No. US 2002/0103468 may be used.
(3) Both-edge folded state:
Thereafter, the webs W1 and W2 with the absorber attached thereto have their folding portions E on both edges folded inward at a position of two-dot dash lines L2 shown in
(4) Two-folded State:
After folding, the webs W1 and W2 are folded into two at a folding line B by a two-folding apparatus 33, whereby the webs W1 and W2 are folded into two as shown in
Thereafter, the webs W1 and W2 folded into two have both edges L sealed (e.g., heat-sealed or sonic-sealed), as shown in
The present apparatus may form pants P from the webs W1 and W2 (hereinafter, referred to as a “stacked web W”) folded into two, using a decelerating drum 34, a main drum 37, a seal roller 35, and a cutter roller 36.
Decelerating Drum 34:
As described above, although the web W has an elastic member, the web W is moved in a stretched state so that placement of an absorber at a predetermined position, formation of a leg hole, and other processing can be performed easily. However, in order to seal the web W and cut a seal portion, the position of the edge L only needs to be determined. This is because the state of the other portions of the web W does not influence a sealing step and a cutting step. Furthermore, in the sealing step, it is preferable that a flow speed of the web W is lower so as to obtain a sufficient time for melting a part of the web W and the like. The decelerating drum can decrease the flow speed of the web W so as to obtain a sufficient time for melting the part of the web W and the like. As the decelerating drum 34, an apparatus described in JP 63-317576 A, International Publication No. WO 01/44086, or U.S. Patent Application No. 2002/0103468 may be used.
The decelerating drum 34 is provided with a plurality of pads 34p rotating in a transport direction of the stacked web W around a drum (not shown). The decelerating drum 34 receives at least an edge L at a receiving position RP from the two-folding apparatus 33 placed upstream therefrom, and holds it. The other portions of the web W are positioned between adjacent pads 34p. The edge L is transported to a releasing position SP, and thereafter, the edge L is supplied to the main drum 37 placed downstream therefrom at the releasing position SP. While the pad 34p moves from the receiving position RP to the releasing position SP, the interval between the adjacent pads 34p is changed to be narrow.
The pad 34p is capable of receiving the edge L in a stretched state at the receiving position RP, and keeping holding the edge L shown in
Main Drum 37:
The main drum 37 receives the web W in a mixed state where the stretched edge L and the shrinking portion S that has shrunk are present alternately from the decelerating drum 34. The main drum 37 transports the web W in such a mixed state. In order to keep the mixed state, the main drum 37 may be provided with, for example, a plurality of suction holes to suck air through the suction holes so as to suck the web W.
Seal Roller 35:
The seal roller 35 can conduct heat-sealing by heating and pressing the edge L (
Formation Operation of Pants P:
Next, an operation of forming pants P from the stacked web W will be described. The decelerating drum 34 continuously receives the web W onto each pad 34p under the condition that the web W is stretched in a flow direction. Herein, the pad 34p holds the edge L (
After receiving the web W, the pad 34p having received the web W has its circumferential velocity decreased, whereby the interval between the adjacent pads 34p becomes narrow. Therefore, a portion S other than the edge L of the web W shown in
Thereafter, the main drum 37 receives the web W from the decelerating drum 34. At this time, the main drum 37 receives the web W in a mixed state where the edge L in a stretched state and the shrinking portion S that has shrunk are present alternately. The main drum 37 transports the web W in a downstream direction while keeping the mixed state. During transportation by the main drum 37, the seal roller 35 presses and heats the edge L of the web W on the main drum 37. Herein, a part of the web W shrinks, so that the transport velocity of the web becomes low. Sealing can be conducted exactly, as the transport velocity of the web W is low.
Thereafter, the web W is cut to individual pieces with a cutter roller 36 to form pants P.
As described above, according to the present invention, after being interposed and fixed between a first web and a second web, an elastic member is cut. Therefore, the stretched elastic member hardly shrinks on the second web, whereby an expected gathering is obtained.
Furthermore, according to the present invention, the elastic member is cut between adjacent first webs. Therefore, the second web and an absorber do not become stiff between the first webs.
Furthermore, a plurality of first webs are placed on a second web under the condition where they are away from each other. Therefore, the first web is not stacked on a portion where a gathering of the elastic member is not formed, so that such a portion becomes thin and allows air to pass there through. As a result, a user wearing such an article is not likely to feel stuffy.
Furthermore, the elastic member is cut between the first webs and at a loose portion of the second web. Therefore,only the elastic member can be cut without damaging the web.
If a pad that makes the second web loose is allowed to transport the second web at a substantially constant velocity during a predetermined period from a time when the pad starts receiving the first web to a time when the pad finishes receiving it, the first web can be transferred to a predetermined position of the second web exactly.
Furthermore, if the elastic member is cut under the condition that the tension stress of the elastic member is increased, the elastic member can be cut easily with infrared rays or the like.
Furthermore, while the web is transported under the condition that an edge (where the web is stretched) and a shrinking portion (where the web shrinks) are present alternately in a transport direction, a heating time for heating the edge becomes long. Therefore, the transport velocity of the web can be increased without impairing the exactness of heat-sealing.
Various other modifications will be apparent to and can be readily made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description as set forth herein, but rather that the claims be broadly construed.
Number | Date | Country | Kind |
---|---|---|---|
2002-241959 | Aug 2002 | JP | national |
2002-312403 | Oct 2002 | JP | national |
The present application is a continuation of commonly assigned, application Ser. No. 10/316,523, filed Dec. 11, 2002, U.S. Pat. No. 7,008,497 and entitled “Method and Apparatus for Producing Wearing Article”, the entire disclosure of which is incorporated herein by reference.
Number | Name | Date | Kind |
---|---|---|---|
3828367 | Bourgeois | Aug 1974 | A |
4425173 | Frick | Jan 1984 | A |
4488923 | Pieniak | Dec 1984 | A |
4506779 | Seragnoli | Mar 1985 | A |
4578133 | Oshefsky et al. | Mar 1986 | A |
4610751 | Eschler | Sep 1986 | A |
4726876 | Tomsovic, Jr. | Feb 1988 | A |
4767487 | Tomsovic, Jr. | Aug 1988 | A |
4880102 | Indrebo | Nov 1989 | A |
4895568 | Enloe | Jan 1990 | A |
5025910 | Lasure et al. | Jun 1991 | A |
5525175 | Blenke et al. | Jun 1996 | A |
5612118 | Schleinz et al. | Mar 1997 | A |
5622581 | Ducker et al. | Apr 1997 | A |
5660657 | Rajala et al. | Aug 1997 | A |
5711832 | Glaug et al. | Jan 1998 | A |
6022443 | Rajala et al. | Feb 2000 | A |
6217690 | Rajala et al. | Apr 2001 | B1 |
6554815 | Umebayashi | Apr 2003 | B1 |
6748996 | Nakakado et al. | Jun 2004 | B2 |
20020046802 | Tachibana et al. | Apr 2002 | A1 |
20020103468 | Nakakado et al. | Aug 2002 | A1 |
20020125105 | Nakakado | Sep 2002 | A1 |
Number | Date | Country |
---|---|---|
0 805 116 | Nov 1997 | EP |
0 974 323 | Jul 1998 | EP |
2 214 202 | Aug 1989 | GB |
1272803 | Oct 1989 | JP |
63317576 | Dec 1998 | JP |
2000-026015 | Jan 2000 | JP |
2001-061890 | Mar 2001 | JP |
9800356 | Jan 1998 | WO |
0076444 | Dec 2000 | WO |
Number | Date | Country | |
---|---|---|---|
20060032589 A1 | Feb 2006 | US |
Number | Date | Country | |
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Parent | 10316523 | Dec 2002 | US |
Child | 11250849 | US |