JP6346024B2 - Thermal welding method and manufacturing method of absorbent article - Google Patents

Description

  The present invention relates to a heat welding method and an absorbent article manufacturing method.

  In the manufacture of disposable paper diapers and the packaging of absorbent articles such as incontinence pads and sanitary napkins, heat fusion is performed by heating and pressing a pair of non-woven fabric and plastic sheets, such as nonwoven fabrics and pressing rolls. There is known a heat welding method for forming a portion and fixing a plurality of heat-meltable sheets.

  When such a heat welding method is used, the temperature and pressure applied to the workpiece are usually optimized, and the heat welding conditions commensurate with the production capacity are set. However, when the heat welding time is shortened for the purpose of improving the production capacity and the like, the fixing strength of the heat welded portion may be lowered. Further, when the heating temperature of the heating roll is increased or the pressure is increased in order to prevent a decrease in the fixing strength, the heat welded part may be burned out or cut, resulting in a defect in the appearance of the product.

  Therefore, in Patent Document 1, in order to increase the fixing strength of the heat welding portion, the workpieces after heat welding are biased toward one of the two heat welding work rolls. A heat sealing method is described in which is conveyed.

  Further, Patent Document 1 describes that the heating temperatures of the upper processing roll and the lower processing roll at the time of heat welding are made different because the thicknesses of the belt-shaped sheets constituting the workpiece are different from each other. That is, conventionally, when heat-welding parts having the same thickness, such as side edges of disposable paper diapers and packaging materials for packages, the heating temperatures of the upper processing roll and the lower processing roll are set to the same temperature. , Was doing heat welding.

JP 2011-126591 A

  However, the method of Patent Document 1 requires a new guiding means for guiding the workpiece. Therefore, as a result of earnest research, the inventor has determined that the adhesion strength between the heat-meltable sheets in the heat-welded part formed in this way depends on the heating temperature, the heating time, the pressing pressure, and the pressing time. In particular, the heating temperature is important, and it has been found that by adjusting the heating temperature of the upper processing roll and the lower processing roll, the fixing strength of the heat welded portion can be increased by a simple apparatus and method.

  Therefore, the object of the present invention is to increase the fixing strength of the heat-welded portion using a simple apparatus and method even if the heat-welding time is shortened for the purpose of improving production capacity for high-speed operation. An object of the present invention is to provide a heat welding method, a method for producing disposable pants, and a method for producing a package.

(1) A thermal welding method according to an embodiment of the present invention includes a first part that can be melted by heat and a second part that is defined separately from the first part and that can be melted by heat. A step of providing a workpiece having the same material and the same thickness as the first portion and the second portion, and a step of facing the first portion and the second portion. And heat-welding the first part and the second part arranged opposite to each other by heating and pressurizing with at least two heating rolls. In the thermal welding step, the two heating rolls are characterized in that the heating temperature of one heating roll is different from the heating temperature of the other heating roll.
(2) A thermal welding method according to another embodiment of the present invention is the thermal welding method according to (1) above, wherein the step of facing the first portion and the second portion is the workpiece. The first part and the second part are opposed to each other by folding the object.
(3) A thermal welding method according to another embodiment of the present invention is the thermal welding method according to (1) or (2) above, wherein the heating temperature of the one heating roll is the first part and The temperature is higher than the melting point of the second part, and the heating temperature of the other heating roll is lower than the melting points of the first part and the second part.
(4) A thermal welding method according to another embodiment of the present invention is the thermal welding method according to any one of (1) to (3) above, wherein the one heating roll is more than the other heating roll. And the heating temperature of the one heating roll is higher than the heating temperature of the other heating roll.
(5) A thermal welding method according to another embodiment of the present invention is the thermal welding method according to any one of (1) to (4) above, wherein the heating temperature of the one heating roll is the first temperature. The heating temperature of the other heating roll is 5 ° C. or more and 10 ° C. or less higher than the melting point of the second portion and the second portion. The temperature is 5 ° C. or higher and lower by 10 ° C. or lower than the melting point.
(6) A thermal welding method according to another embodiment of the present invention is the thermal welding method according to any one of (1) to (5) above, in which the heating temperature of the one heating roll is the other of the other heating rolls. It is characterized in that the temperature is 10 ° C. or higher and 20 ° C. or lower than the heating temperature of the heating roll.
(7) A thermal welding method according to another embodiment of the present invention is the thermal welding method according to any one of (1) to (6) above, wherein the one heating roll includes a plurality of heating block pieces. The heat welding part which has a heating block on the surface and includes a plurality of welding part pieces is formed by the heating block piece.
(8) A method for manufacturing disposable pants according to an embodiment of the present invention is characterized by using the thermal welding method according to any one of (1) to (7) above.
(9) A method for manufacturing a package according to an embodiment of the present invention is a method for manufacturing a package including a packaged article and a packaging material for packaging the packaged article, and the above (1) to (7) The heat welding method described in any one of the above is used.

  The heat welding method, the manufacturing method of the disposable pants, and the manufacturing method of the package of the present invention use a simple apparatus and method even if the heat welding time is shortened for the purpose of improving the production capacity for high-speed operation. The fixing strength of the heat welded portion can be increased.

It is the schematic explaining the heat welding method of this embodiment. It is the schematic explaining the upper side heating roll and lower side heating roll which are used for the heat welding method of this embodiment. It is a perspective view which shows the disposable diaper manufactured using the heat welding method of this embodiment. It is process drawing explaining the manufacturing method of the disposable diaper of FIG. 3 using the heat welding method of this embodiment. It is process drawing explaining the manufacturing method of the disposable diaper of FIG. 3 using the heat welding method of this embodiment. It is process drawing explaining the manufacturing method of the disposable diaper of FIG. 3 using the heat welding method of this embodiment. (A) It is the schematic explaining the arrangement pattern of the heating block piece in the heating block formed in the surrounding surface part of the upper side heating roll used for the thermal welding method of this embodiment, (b) In the thermal welding method of this embodiment It is the schematic explaining the arrangement pattern of the heating block piece in the heating block formed in the surrounding surface part of the lower side heating roll to be used. (A) It is the schematic explaining the arrangement pattern of the heating block piece in the heating block formed in the surrounding surface part of the upper side heating roll used for the thermal welding method of this embodiment, (b) In the thermal welding method of this embodiment It is the schematic explaining the arrangement pattern of the heating block piece in the heating block formed in the surrounding surface part of the lower side heating roll to be used. It is process drawing explaining the manufacturing method of the package of FIG. 9 using the heat welding method of this embodiment. It is a process figure explaining the manufacturing method of the packaging body of FIG. 9 using the heat welding method of this embodiment, and a perspective view which shows the packaging body manufactured using the heat welding method of this embodiment. It is a perspective view which shows the modification of the package manufactured using the heat welding method of this embodiment.

  DESCRIPTION OF EMBODIMENTS Hereinafter, a mode for carrying out the present invention (hereinafter referred to as “the present embodiment”) will be described with reference to the accompanying drawings. Note that the same number is assigned to the same element throughout the description of the embodiment.

[Thermal welding method]
As shown in FIGS. 4 and 9, the thermal welding method according to the present embodiment includes a first portion 12 that can be thermally melted and a second portion 14 that can be thermally melted separately from the first portion 12. And a workpiece 1 including: The first portion 12 and the second portion 14 may be disposed apart from each other or may be disposed adjacent to each other. The first portion 12 and the second portion 14 are made of the same material and have the same thickness. That is, the first portion 12 and the second portion 14 may be portions defined in one sheet or in a set of sheet stacks including a plurality of sheets. Further, the first portion 12 and the second portion 14 may be portions defined by different bodies made of the same material and having the same thickness. As shown in FIG. In the first sheet and the second sheet made of the same material, the first sheet 12 is defined in the first sheet, and the second sheet 14 is defined in the second sheet. Good.

  Next, the first portion 12 and the second portion 14 are arranged to face each other. This may be done by folding the workpiece 1 as shown in FIG. 5 or FIG. 10, or as shown in FIG. 11, the second sheet being separate from the first sheet. The workpiece 1 may be provided and the sheet may be disposed to face the workpiece 1.

  The workpiece 1 is transported between at least two heated rolls 22 and 24 shown in FIG. 1, and at least the first part 12 and the second part 14 are heated and heated using the heated rolls 22 and 24. By pressurizing, for example, as shown in FIGS. 3, 6, 10, and 11, the first portion 12 and the second portion 14 are thermally welded to form the thermally welded portion 16.

  As shown in FIG. 1, the at least two heating rolls 22, 24 include an upper heating roll 22 and a lower heating roll 24, and a peripheral surface portion of the upper heating roll 22 and a peripheral surface portion of the lower heating roll 24. Are arranged adjacent to each other so as to face each other. For example, the upper heating roll 22 and the lower heating roll 24 are juxtaposed in any one of the vertical direction, the horizontal direction, and the diagonal direction. Note that the upper heating roll 22 and the lower heating roll 24 rotate in opposite directions to convey the workpiece 1 in the longitudinal direction (MD direction), and roll axes that cross the longitudinal direction (MD direction). Is driven to rotate around the center axis. The at least two heating rolls 22 and 24 may further include other heating rolls in addition to the upper heating roll 22 and the lower heating roll 24.

  In this heat welding step, the heating temperature of the upper heating roll 22 is different from the heating temperature of the lower heating roll 24. The heating temperature here refers to the surface temperature of the portion of the upper heating roll 22 that contacts the first portion 12 or the surface temperature of the portion of the lower heating roll 24 that contacts the second portion 14. Say. In the heating rolls 22 and 24 shown in FIG. 2, the surface temperature of the heating block 22P of the upper heating roll 22 and the surface temperature of the heating block 24P of the lower heating roll 24 are shown. In this heat welding step, at least one of the heating temperature of the upper heating roll 22 and the heating temperature of the lower heating roll 24 is higher than the melting point of the first portion 12 and the second portion 14. This is because the first part 12 and the second part 14 are requirements for heat welding.

  According to this, since the fixing strength of the heat welding part 16 formed by heat welding can be increased as compared with the conventional case where welding is performed at the same heating temperature, the heat welding part 16 is torn. This makes it difficult to cause burnout of the heat-welded portion 16, so that a product with a good appearance can be manufactured.

  In this heat welding step, the heating temperature of one of the upper heating roll 22 and the lower heating roll 24 is higher than the melting point of the first portion 12 and the second portion 14, and the upper heating roll 22. The other heating temperature of the lower heating roll 24 may be lower than the melting points of the first portion 12 and the second portion 14. This is because, as a result of the experiment, in this case, the fixing strength of the heat welded portion 16 can be further increased, and the heat welded portion 16 was not burned out.

  Furthermore, in the above heat welding step, the heating temperature of the upper heating roll 22 is preferably higher than the heating temperature of the lower heating roll 24. This is because, as a result of the experiment, in this case, the fixing strength of the heat welded portion 16 can be increased, and no burnout was observed in the heat welded portion 16.

  The heating temperature of one of the upper heating roll 22 and the lower heating roll 24 is a temperature that is 5 ° C. or more and higher by 10 ° C. or less than the melting point A of the first portion 12 and the second portion 14. The other heating temperature of the upper heating roll 22 and the lower heating roll 24 is 5 ° C. or more and lower by 10 ° C. or less than the melting point A of the first portion 12 and the second portion 14. The first portion 12 and the second portion 14 may be heated and thermally welded.

  In other words, the heating temperature of one of the upper heating roll 22 and the lower heating roll 24 is (A + 5) ° C. or higher with respect to the melting point A of the first portion 12 and the second portion 14. (A + 10) ° C. or lower, and the other heating temperature of the upper heating roll 22 and the lower heating roll 24 is (A−10) ° C. with respect to the melting point A of the first portion 12 and the second portion 14. It is above and becomes (A-5) degrees C or less.

  Furthermore, in other words, the heating temperature of one of the upper heating roll 22 and the lower heating roll 24 is 10 ° C. or more than the other heating temperature of the upper heating roll 22 and the lower heating roll 24. It can be said that it may be higher by 20 ° C. or less. In this case, while the temperature control is easy, the fixing strength of the heat welded portion 16 becomes a certain value or more, the reliability of the product can be increased, and the heat welded portion 16 can be prevented from being burned out.

  In these cases, since the temperature difference between the heating temperatures of the two heating rolls 22 and 24 is small, the temperature control is easy, while the fixing strength can be secured above a certain level, and the welded portion does not burn out. Therefore, even if the heat welding time is shortened for the purpose of improving production capacity for high-speed operation, the reliability of the product can be further increased.

  The melting points of the first portion 12 and the second portion 14 are not particularly limited, but are preferably 100 ° C. or higher and 200 ° C. or lower, more preferably 105 ° C. or higher and 180 ° C. or lower. For example, when a spunbonded nonwoven fabric having a melting point of 180 ° C. is used for at least the first portion 12 and the second portion 14, a heating roll for heating and heat-welding the first portion 12 and the second portion 14. The upper heating roll 22 is 185 ° C. or higher and 190 ° C. or lower, and the lower heating roll 24 is 170 ° C. or higher and 175 ° C. or lower.

As shown in FIG. 2, the upper heating roll 22 has a heating block 22P on the circumferential surface, and the lower heating roll 24 has a heating block 24P on the circumferential surface. As shown in FIG. 2, the heating block 22P may be flush with the peripheral surface of the heating roll 22, or between the tip of the heating block 22P and the peripheral surface of the heating roll 22 as shown in FIG. There may be a step, and the heating block 22P may be convex with respect to the peripheral surface. As shown in FIG. 2, the heating block 24P may also be flush with the peripheral surface of the heating roll 24, or the leading end of the heating block 24P and the peripheral surface of the heating roll 24 as shown in FIG. There may be a step between them, and the heating block 22P may be convex with respect to the peripheral surface. The heating blocks 22P and 24P are provided at positions that equally divide the circumferential direction of the heating rolls 22 and 24, respectively. For example, as shown in FIG. 2, six heating blocks 22 </ b> P and 24 </ b> P are attached to the heating rolls 22 and 24 at positions where the roll circumferential direction is equally divided into six. The heating temperatures of the heating blocks 22P and 24P are controlled by control means (not shown).
As shown in FIG. 7A, one heating block 22 </ b> P has a plurality of heating block pieces 221. The plurality of heating block pieces 221 may be arranged side by side on a straight line along the roll axis direction of the peripheral surface portion of the upper heating roll 22 with a predetermined distance therebetween. Similarly, as shown in FIG. 7B, one heating block 24 </ b> P has a plurality of heating block pieces 241. The plurality of heating block pieces 241 may be arranged side by side on a straight line along the roll axis direction of the peripheral surface portion of the lower heating roll 24, separated from each other by a predetermined distance. In the heat welding step, the heating rolls 22 and 24 are rotated about the roll axis so that the heating block piece 221 and the heating block piece 241 face each other. According to this, the heat welding part 16 which has several intermittent welding part pieces 161 as shown in FIG. 3 in the 1st part 12 and the 2nd part 14 can be formed. Even if such a plurality of welding part pieces 161 are formed by performing heat welding with the heating temperature of the heating roll controlled using the above heat welding method, the plurality of welding part pieces 161 are attracted to each other. However, the appearance of the heat welding part 16 can be formed satisfactorily. The arrangement pattern of the heating block pieces 221 and 241 can be changed without particular limitation. For example, as shown in FIGS. 8A and 8B, the heating blocks 22P and 24P include In addition, a configuration in which a plurality of dot-shaped heating block pieces 223 and 243 are provided in an elongated rectangular shape along the axial direction of the heating rolls 22 and 24 can be used. The plurality of heating block pieces 223 and 243 are provided side by side on a plurality of lines at regular intervals.

  The workpiece 1 described so far includes an absorbent article, disposable pants, a heating element capable of generating heat by contact with air, and an intermediate such as a package in which the package is packaged with a packaging material. Examples of the absorbent article include a substantially rectangular absorbent article such as a urine pad, a light incontinence pad, a urine removing liner, and a sanitary napkin, and a disposable pants-type absorbent article. Disposable pants include pants-type absorbent articles (disposable diapers), disposable pants bodies such as paper pants and non-woven pants.

[Production method of disposable pants]
The manufacturing method of the disposable pants of this embodiment manufactures disposable pants using the heat welding method of the said this embodiment. Hereinafter, the disposable diaper 2 shown in FIG. 3 will be described as an example of the disposable pants. The disposable diaper 2 is a pants-type absorbent article that is worn at least on the crotch part of the body for the purpose of absorbing bodily fluids discharged from the body.

  The disposable diaper 2 includes a liquid-absorbing absorbent member 111 and an exterior material 135 that is disposed on the non-skin contact surface side of the absorbent member 111 and that defines a leg opening 131 and a trunk opening 133. The absorbing member 111 is fixed to the exterior material 135 via an adhesive. The absorbing member 111 includes a pair of side flaps 140 provided along both side edges extending in the longitudinal direction. The exterior material 135 is gathered by a plurality of leg opening elastic members 137 and trunk opening elastic members 139 along the leg opening 131 and the trunk opening 133. The exterior material 135 has a laminated structure in which at least the interior sheet 135A and the exterior sheet 135B are laminated, or a single layer structure composed of one of them, and at least one of the interior sheet 135A and the exterior sheet 135B has elasticity. ing. In the disposable diaper 2 of the present embodiment, the exterior sheet 135B constitutes the outer surface of the disposable diaper 2, and the interior sheet 135A is disposed on the inner surface side of the disposable diaper 2. The leg opening elastic member 137 and the trunk opening elastic member 139 are disposed between the interior sheet 135A and the exterior sheet 135B.

  As shown in FIG. 4, in the first embodiment, the workpiece 1 includes a plurality of absorbent members 111 that become the disposable diaper 2 of FIG. 3 along the longitudinal direction (MD direction) that is the transport direction. It is the diaper continuous body 120 made.

  First, as shown in FIG. 4, a diaper continuous body 120 having a continuous web 121 for exterior material to be the exterior material 135 and an absorbent member 111 fixed to the skin contact surface side of the continuous web 121 for exterior material is provided. A plurality of absorbent members 111 are arranged at predetermined intervals in the longitudinal direction (MD direction) in the central region in the short direction (CD direction) crossing the transport direction, and the back side is longitudinally ( It is fixed on the exterior material continuous web 121 conveyed in the MD direction). The exterior material continuous web 121 is formed with a notch or an opening 116 that becomes a leg opening 131 provided by cutting away a part of the region where the absorbing member 111 is not provided.

  A plurality of leg opening elastic members 137 and trunk opening elastic members 139 are fixed to the exterior material continuous web 121 with a hot melt adhesive or the like. The continuous web 121 for exterior material may have air permeability from the viewpoint of preventing stuffiness or the like, or may be one in which a plurality of openings and slits for ventilation are formed in part. The exterior material continuous web 121 is made of one or more layers of sheets, and may be made of plastic, rubber, nonwoven fabric, paper, or the like. The exterior material continuous web 121 may include a liquid-impermeable sheet in at least one layer. In this case, the exterior material continuous web 121 includes an inner sheet 121A that becomes the interior sheet 135A and an outer sheet 121B that becomes the exterior sheet 135B, and a plurality of strips are provided between the inner sheet 121A and the outer sheet 121B. The leg opening elastic member 137 and the trunk opening elastic member 139 are fixed with an adhesive. For example, the exterior material continuous web 121 is a laminated sheet obtained by laminating an inner sheet 121A that is a liquid-impermeable plastic or rubber film sheet and an outer sheet 121B that is a breathable fiber nonwoven fabric. Also good. On the other hand, the exterior material continuous web 121 may be a single-layer sheet made of hydrophobic fibers, fibers such as nonwoven fabric subjected to hydrophobic treatment, or a liquid-impermeable plastic or rubber film sheet. This laminated sheet or single layer sheet may have at least one of at least one of longitudinal and lateral stretchability and air permeability.

  And in the diaper continuum 120, the first part 12 that can be thermally melted disposed on the side of the torso when worn, and the first part 12 when the disposable diaper 2 is formed are disposed, In the diaper continuous body 120, one or a plurality of heat-meltable second portions 14 separated from the first portion 12 are defined. The first portion 12 and the second portion 14 are portions that are spaced apart from each other in a set of sheet laminates composed of one or a plurality of sheets. This heat-meltable portion includes at least a heat-meltable material.

  Each absorbent member 111 is fixed to the exterior material continuous web 121 in a region defined by a pair of adjacent first portions 12 and a pair of adjacent second portions 14. For example, the 1st part 12 and the 2nd part 14 are prescribed | regulated in the area | region where the absorption member 111 of the continuous web 121 for exterior materials is not provided in the diaper continuous body 120, and the continuous web 121 for exterior materials is heat | fever. Consists of meltable materials.

  The absorbent member 111 includes a liquid-permeable top sheet, a liquid-impermeable back sheet, and a liquid-retaining absorbent between them. For example, as the absorbent body of the absorbent member 111, a mixture of cotton-like pulp and SAP (highly water-absorbent resin), or one having a highly water-absorbent resin supported between hydrophilic nonwoven fabrics can be used.

  The pair of side flaps 140 is provided along the longitudinal direction at the end in the width direction of the absorbing member 111 and has a function of preventing side leakage of body fluid such as urine. For this reason, the side flap 140 is preferably made of a fiber such as a hydrophobic fiber or a non-woven fabric subjected to a hydrophobic treatment. The side flap 140 may be provided with a so-called three-dimensional gather in which one or a plurality of strand-like or string-like elastic members are arranged along the longitudinal direction of the side flap 140 and are erected in three dimensions.

  Next, as shown in FIG. 5, the diaper continuum 120 is folded at a substantially central line in a direction (CD direction) crossing the length direction (MD direction) indicated by the one-dot chain line in FIG. 12 and the second portion 14 are stacked facing each other. At this time, the exterior material continuous web 121 may be stretched so that the shrinking force of the trunk opening elastic member 139 or the like does not cause a defect in the subsequent heat welding process.

  The folded diaper continuous body 120 is transported between at least two heating rolls 22 and 24 shown in FIG. 1 by the above-described heat welding method, and the first portion 12 and the second portion 14 are heated. By heating and pressurizing with the heating blocks 22P and 24P of 22 and 24, as shown in FIG. 6, the first portion 12 and the second portion 14 are thermally welded, and the thermally welded portion 16 is formed. . The heat welding part 16 may have a plurality of intermittent welding part pieces 161.

(Cutting process)
The diaper continuous body 120 in which the first portion 12 and the second portion 14 are heat-welded is further conveyed to a cutting means, and is cut between the adjacent heat-welded portions 16 along the alternate long and short dash line shown in FIG. The disposable diaper 2 is manufactured. Although the disposable pants manufacturing method of the present embodiment has been described using the disposable diaper 2, the disposable pants body such as paper pants and nonwoven pants omits the step of providing the absorbent member 111 in the manufacturing method of the disposable diaper 2. Can be manufactured.

[Method for producing package 3]
The manufacturing method of the package 3 of this embodiment manufactures the package 3 using the heat welding method of this embodiment. The package 3 of the present embodiment includes a packaged object 302 such as an absorbent article, and a packaging material 301 folded to wrap the packaged object 302. Absorbent articles are to be worn at least in the crotch of the body for the purpose of absorbing bodily fluids discharged from the body, such as urine pads, light incontinence pads, urine removing liners, sanitary napkins, etc. Examples include substantially rectangular absorbent articles and disposable pants-type absorbent articles.

  The manufacturing method of the package 3 of this embodiment is demonstrated using FIG. 9 and FIG. First, as shown in FIG. 9, an object 302 to be packaged is fixed to the surface of the packaging material 301 with an adhesive or the like. The packaging material 301 includes a first portion 12 at one end, a second portion 14 at the other end separated from the first portion 12, a first portion 12, and a second portion, as indicated by a broken line portion. A third portion 18 sandwiched between the two portions 14 is defined along a side edge of at least one packaging material 301.

  The first portion 12 and the second portion 14 of the packaging material 301 can be heat-welded. The material of the packaging material 301 is not particularly limited, and examples thereof include plastic films such as polyethylene, polypropylene and polyester, various films such as nylon films, breathable films stretched with fillers such as barium sulfate, and spans. It is at least one of a non-woven fabric such as a bond, SMS (spun bond, meltblown, spunbond three-layer structure), a non-woven fabric laminated film, or a combination thereof. Note that the packaging material 301 may be composed of a single layer or a plurality of layers made of different materials. The third portion 18 is heat-sealable, like the first portion 12 and the second portion 14, is made of the same material as the first portion 12 and the second portion 14, and Present the same thickness.

  Next, the packaging material 301 and the packaging object 302 are folded over and the first part 12 and the second part 14 are disposed facing each other with the packaging object 302 fixed. At this time, the first portion 12 and the second portion 14 are also arranged to face the third portion 18.

  Next, at least the first portion 12 and the second portion 14 are formed along the side edge of the package 3 composed of the folded packaging material 301 and the packaged object 302 by using the above-described heat welding method. The heat welding part 16 is formed by heat welding. At this time, the third portion 18 is also thermally welded to the first portion 12 and the second portion 14 at the same time. The folded package 3 is conveyed between at least two heated heating rolls 22 and 24 shown in FIG. 1, and the first part 12 and the second part 14 are used by using at least the heating rolls 22 and 24. Are heated and pressurized. Thereby, as shown in FIG. 10, the 1st part 12 and the 2nd part 14 are heat-welded, and the heat welding part 16 is formed. On the peripheral surfaces of the heating rolls 22 and 24, heating blocks 22P and 24P having a predetermined pattern may be provided. For example, as shown in FIG. 8A and FIG. 8B, the heating blocks 22P and 24P have a plurality of dot-shaped heating blocks in an elongated rectangular shape along the axial direction of the heating rolls 22 and 24. Those provided with the pieces 223 and 243 can be used. The plurality of heating block pieces 223 and 243 are provided side by side on a plurality of lines at regular intervals.

  Here, the description has been made using a tri-fold package, but it goes without saying that it may be a double-fold or a multi-fold package other than these. In the case of folding in half, the third portion 18 is omitted.

  In addition, as a modified example of the manufacturing method of the packaging body of the present embodiment, instead of the folded packaging material 301, separate packaging material 301A and packaging material 301B may be used. The packaging material 301A and the packaging material 301B are made of the same material and have the same thickness. In this case, along the circumference of the packaging material 301 </ b> A and the packaging material 301 </ b> B, the heating rolls 22 and 24 are used to form the heat welding part 16 </ b> A having a plurality of welding part pieces 163 </ b> A so 3A is provided. In this case, the heating rolls 22 and 24 may have heating blocks 22P and 24P arranged in a frame shape.

  Hereinafter, the welding method of the present embodiment will be described more specifically with reference to examples.

[Production of Workpiece 1] A workpiece having a first portion in which three spunbond nonwoven fabrics having a basis weight of 17 g / m ² are stacked and a second portion in which three similar spunbond nonwoven fabrics are stacked is covered. Workpiece 1 was obtained. The workpiece 1 is used as an upper heating roll, a pressing roll having the heating block shown in FIG. 7 (a) is used, and the lower heating roll is used as an anvil roll having the heating block shown in FIG. 7 (b). A heat-welded portion was formed on the side edge portion of the workpiece 1 at a constant pressure of 3 MPa. The heating temperature of the pressing roll and the anvil roll was set as shown in Table 1. In Table 1, A indicates a melting point and is 180 ° C. in the case of the workpiece 1. An anvil roll heating temperature and a pressing roll heating temperature were the same as a comparative example.

[Measuring Method] One end of the first portion and one end of the second portion were pulled using a tensile tester to measure the fixing strength of the heat welded portion. The measurement was performed at a tensile speed of 500 mm / min. The measurement results are shown in Table 1.

[Evaluation Method] For the fixing strength, a value of 39.2 N (= 4 kgf) / 3 inch or more is marked as ◎, and less than 39.2 N (= 4 kgf) / 3 inch and 34.3 N (= 3.5 kgf) / 3 inch. Is less than 34.3 N (= 3.5 kgf) / 3 inch, more than 29.4 N (= 3 kgf) / 3 inch, and less than Δ, 29.4 N (= 3 kgf) / 3 inch The thing was set as x.

  As mentioned above, although this invention was demonstrated using embodiment, it cannot be overemphasized that the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiments. Further, it is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Workpiece 2 Disposable diaper 3, 3A Package 12 1st part 14 2nd part 16, 16A Thermal welding part 161 Welding part piece 163,163A Welding part piece 18 3rd part 22 Upper side heating roll 22P Heating block 221 Heating block piece 223 Heating block piece 24 Lower heating roll 24P Heating block 241 Heating block piece 243 Heating block piece 111 Absorbing member 116 Opening, notch 120 Band-like laminate 121 Exterior material continuous web 131 Leg opening 133 Trunk opening Part 135A Interior sheet 135B Exterior sheet 137 Leg opening elastic member 139 Body opening elastic member 140 Side flaps 301, 301A, 301B Packaging materials 302, 302A

Claims (8)

A work piece comprising a first part that is heat-meltable and a second part that is separately defined and heat-meltable, the first part and the second part Providing a workpiece with the same material and thickness as the part;
Opposing the first part and the second part;
A step of heat-welding the first part and the second part arranged opposite to each other by heating and pressurizing with at least two heating rolls,
In the heat welding step, the two heating rolls, Ri heating temperature of one of the heating roll and the other of the heating temperature of the heating roll Do different,
The heating temperature of the one heating roll is higher than the melting points of the first part and the second part, and the heating temperature of the other heating roll is the first part and the second part. A heat welding method characterized in that the temperature is lower than the melting point of the part . A work piece comprising a first part that is heat-meltable and a second part that is separately defined and heat-meltable, the first part and the second part Providing a workpiece with the same material and thickness as the part;
Opposing the first part and the second part;
A step of heat-welding the first part and the second part arranged opposite to each other by heating and pressurizing with at least two heating rolls,
In the heat welding step, the two heating rolls, Ri heating temperature of one of the heating roll and the other of the heating temperature of the heating roll Do different,
The one heating roll is disposed above the other heating roll, and the heating temperature of the one heating roll is higher than the heating temperature of the other heating roll . A work piece comprising a first part that is heat-meltable and a second part that is separately defined and heat-meltable, the first part and the second part Providing a workpiece with the same material and thickness as the part;
Opposing the first part and the second part;
A step of heat-welding the first part and the second part arranged opposite to each other by heating and pressurizing with at least two heating rolls,
In the heat welding step, the two heating rolls, Ri heating temperature of one of the heating roll and the other of the heating temperature of the heating roll Do different,
The heating temperature of the one heating roll is a temperature that is 5 ° C. or more and higher by 10 ° C. or less than the melting points of the first part and the second part, and the heating temperature of the other heating roll is The thermal welding method, wherein the temperature is 5 ° C. or higher and 10 ° C. or lower with respect to the melting points of the first portion and the second portion . A work piece comprising a first part that is heat-meltable and a second part that is separately defined and heat-meltable, the first part and the second part Providing a workpiece with the same material and thickness as the part;
Opposing the first part and the second part;
A step of heat-welding the first part and the second part arranged opposite to each other by heating and pressurizing with at least two heating rolls,
In the heat welding step, the two heating rolls, Ri heating temperature of one of the heating roll and the other of the heating temperature of the heating roll Do different,
The heating temperature of the one heating roll is 10 ° C. or more and 20 ° C. or less higher than the heating temperature of the other heating roll . A heat welding method according to any one of claims 1 to 4 ,
The step of facing the first portion and the second portion is the heat welding characterized in that the first portion and the second portion are opposed to each other by folding the workpiece. Method. A heat welding method according to any one of claims 1 to 5 ,
The one heating roll has a heating block having a plurality of heating block pieces spaced from each other on the surface, and the heat welding part including a plurality of welding part pieces is formed by the heating block piece. Heat welding method to do. Method for producing disposable pants, which comprises using a heat welding method according to any one of claims 1 to 6. A method for manufacturing a package including a packaged article and a packaging material for packaging the packaged article, wherein the method for heat-sealing according to any one of claims 1 to 6 is used. .

Images