CN108349601B

CN108349601B - Method for manufacturing package

Info

Publication number: CN108349601B
Application number: CN201680063493.0A
Authority: CN
Inventors: 佃淳志
Original assignee: Unicharm Corp
Current assignee: Unicharm Corp
Priority date: 2015-10-30
Filing date: 2016-09-12
Publication date: 2020-06-09
Anticipated expiration: 2036-09-12
Also published as: JP2017081627A; WO2017073185A1; JP6305386B2; CN108349601A

Abstract

A method of sequentially manufacturing packages, comprising: a detection step of detecting the length of a predetermined number of absorbent articles in a first direction; a winding step of winding the packaging sheet around the predetermined number of absorbent articles in a tubular shape with the open end thereof positioned on the end face of the predetermined number of absorbent articles in the first direction, in a state in which the entire predetermined number of absorbent articles are compressed in at least a second direction orthogonal to the first direction; a folding step of folding the open end of the packaging sheet so as to be along the end faces of a predetermined number of absorbent articles; a sealing step of heat-sealing an open end of the packaging sheet folded in the folding step by pressing a heating mechanism against the open end; and a position control step of changing the position of the heating means in the first direction in accordance with the length of the predetermined number of absorbent articles detected in the detection step, when no absorbent article is present in the sealing step.

Description

Method for manufacturing package

Technical Field

The present invention relates to a method for sequentially manufacturing a package in which absorbent articles having a thermoplastic material are packaged.

Background

Patent document 1 discloses a technique of storing a plurality of individually packaged absorbent articles together in a storage bag using a packaging material. Examples of absorbent articles include sanitary napkins and panty liners. The wrapping material for wrapping the absorbent articles individually is made of, for example, a film of polyethylene, polypropylene, polyester, or the like. Patent document 1 does not disclose a method of packaging a plurality of absorbent articles in a storage bag.

Patent document 2 discloses a method of manufacturing a sealed package enclosing a group of cigarettes. According to the manufacturing method described in patent document 2, a sheet of the wrapping material is first bent into a U-shape so as to surround the cigarette group. Then, both ends of the U-shape of the packaging material are overlapped with each other, and both ends overlapped with each other are heat-sealed to each other. Thereby, the wrapping material becomes a tubular shape enclosing the group of cigarettes. In addition, at this time, both end portions of the tubular packaging material are opened. Then, the opened both end portions of the tubular packaging material are heat-sealed to complete the sealed package.

Documents of the prior art

Patent document

Patent document 1: international publication No. 2014/157325

Patent document 2: japanese patent laid-open publication No. 2006-206192

Disclosure of Invention

When packaging an absorbent article individually packaged, it is conceivable to form the outer packaging body for packaging into a shape conforming to the shape of the contained object so that only a part of the outer packaging body for packaging does not protrude from the contained object. By packaging in this manner, the size of the product including the outer package for packaging and the contained object can be suppressed. In this case, in a state where the contents are packaged in the packaging outer package, the outer package and the contents are heat-sealed while being pressed, thereby producing a sealed package.

The inventors of the present application have found that the following problems occur when an absorbent article is packaged by such a packaging method.

The absorbent article has a structure in which a plurality of relatively soft nonwoven fabrics and absorbers are laminated with each other. Therefore, when compared with a relatively hard article such as a cigarette, the size of the absorbent article may fluctuate greatly from a previously designed design value. For example, even if a plurality of absorbent articles are manufactured based on the same design, there is a large fluctuation in size for each absorbent article.

When producing a sealed package, such an absorbent article is packaged in an outer packaging body for packaging, and heat-sealed while pressing the outer packaging body and the absorbent article. Here, when the size of the absorbent article becomes larger than the designed value, the pressing force applied to the absorbent article at the time of heat sealing becomes larger than the designed value. Thus, heat is supplied to the outer package and the absorbent article more than necessary. Since a packaging material for individually packaging absorbent articles generally has thermoplasticity, it may be heat-welded to an outer packaging body for packaging with heat exceeding a necessary level.

When the size of the absorbent article is smaller than the design value, the pressing force applied to the absorbent article at the time of heat sealing becomes smaller than the value designed in advance. Therefore, there is a fear that the outer package cannot be heat-sealed sufficiently.

Therefore, an improved method for hermetically packaging an absorbent article which is likely to have a variation in outer dimensions and is inferior in heat resistance has been desired.

The method according to one aspect relates to a method for sequentially manufacturing a package in which a predetermined number of absorbent articles having a thermoplastic material are packaged. The method comprises the following steps: a detection step of detecting a length of the predetermined number of absorbent articles in a first direction; a winding step of winding a wrapping sheet around the predetermined number of absorbent articles in a tubular shape with an open end positioned at an end face of the predetermined number of absorbent articles in a first direction, in a state where the entire predetermined number of absorbent articles are compressed in at least a second direction orthogonal to the first direction; a folding step of folding the open end of the package sheet so as to be along end faces of the predetermined number of absorbent articles; a sealing step of heat-sealing the open end of the packaging sheet folded in the folding step by pressing a heating mechanism against the open end of the packaging sheet; and a position control step of, when no absorbent article is present in the sealing step, changing the position of the heating means in the first direction in accordance with the length of the predetermined number of absorbent articles detected in the detection step.

An apparatus according to one aspect relates to an apparatus for sequentially manufacturing a package in which a predetermined number of absorbent articles having a thermoplastic material are packaged. The device comprises: a detection unit that detects a length of the prescribed number of absorbent articles in a first direction; a winding unit that winds a wrapping sheet around the predetermined number of absorbent articles in a tubular shape with an open end thereof positioned on an end face of the predetermined number of absorbent articles in the first direction, in a state where the entire predetermined number of absorbent articles are compressed at least in a second direction orthogonal to the first direction; a folding unit that folds the open end of the package sheet so as to follow end faces of the predetermined number of absorbent articles; a sealing unit; the sealing unit heat-seals the open end of the packaging sheet by pressing a heating mechanism against the open end of the packaging sheet folded in the folding unit; and a position control unit that changes a position of the heating mechanism in the first direction in accordance with a length of the predetermined number of absorbent articles detected by the detection unit when no absorbent article is present in the sealing unit.

Drawings

Fig. 1 is a schematic view showing an absorbent article according to an embodiment folded at a first lengthwise folding line along a lengthwise direction.

Fig. 2 is a schematic view showing an absorbent article folded at a first longitudinal folding line and a second longitudinal folding line along the longitudinal direction.

Fig. 3 is a schematic view showing the absorbent article being folded.

Fig. 4 is a schematic view showing an overview of a method of sequentially manufacturing the packages according to an embodiment.

Fig. 5 is a schematic perspective view showing a detection step.

Fig. 6 is a schematic side view showing a unit for performing the first sealing step and the second sealing step.

Fig. 7 is a schematic view showing a case of heat sealing in the first sealing step.

Fig. 8 is a schematic side view of a folding unit.

Fig. 9 is a schematic plan view showing a folding process.

Fig. 10 is a schematic view showing a second sealing step.

Detailed Description

The following describes embodiments with reference to the drawings. In the following description of the drawings, the same or similar reference numerals are given to the same or similar parts. However, the drawings are schematic, and it should be noted that the proportions and the like of the respective dimensions are different from the actual ones in some cases. Therefore, specific dimensions and the like should be determined in consideration of the following description. Further, the drawings may include portions having different dimensional relationships, ratios, and the like.

(1) Unitary structure of absorbent article

An absorbent article according to an embodiment will be described with reference to fig. 1 to 3. Fig. 1 to 3 show an absorbent article 1 and a method of folding the absorbent article 1. In the present embodiment, the absorbent article 1 is a sanitary napkin. Alternatively, the absorbent article may be any absorbent article such as an absorbent pad or a disposable diaper.

The absorbent article 1 may have: a liquid-permeable front sheet that is permeable to liquid, a liquid-impermeable back sheet that is impermeable to liquid, and an absorbent body between the front sheet and the back sheet. On the back side of the back sheet of the absorbent article, a wrapping material 2 for individually wrapping the absorbent articles 1 is provided. Examples of the material of the wrapping material 2 include thermoplastic materials such as polyethylene, polypropylene, and polyester. The absorbent article 1 is individually wrapped with the wrapping material 2 by folding the absorbent article 1 and the wrapping material 2.

Specifically, first, the absorbent article 1 and the wrapping material 2 are folded back inward with the first longitudinal direction folding line FL1 (see fig. 1) along the longitudinal direction L as a starting point. Next, the absorbent article 1 and the wrapping material 2 are folded back inward with a second longitudinal direction folding line FL2 (see fig. 2) along the longitudinal direction L as a base point. Then, the absorbent article 1 and the wrapping material 2 are folded back inward with the first widthwise folding line FW1 and the second widthwise folding line FW2 along the widthwise direction W as base points. In a state where the absorbent article 1 is folded, the end portion of the packaging sheet 2 is adhered to another portion of the packaging sheet 2 by the adhesive tape 4 (see fig. 3). Thereby, the absorbent article 1 is covered with the wrapping material 2.

Hereinafter, the term "absorbent article" refers to the absorbent article 1 covered with the wrapping material 2.

(2) Method for manufacturing package

Next, a method of sequentially manufacturing a package in which a predetermined number of absorbent articles are packaged will be described with reference to fig. 4 to 10. Fig. 4 is a schematic view showing an overview of a method of sequentially manufacturing the packages according to an embodiment. A method of sequentially manufacturing a package according to an embodiment has: a detection process S1, a winding process S2, a first sealing process S3, a folding process S4, and a second sealing process S5.

In the method, first, a plurality of absorbent articles are prepared. The absorbent articles, as mentioned above, may also be individually wrapped by a wrapper comprising a thermoplastic material. The individually packaged absorbent articles 1 are folded over each other by a prescribed number. Hereinafter, a predetermined number of absorbent articles stacked on top of each other will be referred to as "packaged bodies 10".

In the package manufacturing apparatus, a plurality of packaged objects 10 are sequentially conveyed on a manufacturing line. Thereby, the plurality of packaged bodies 10 are sequentially packaged by the packaging sheet 12.

A detection step S1 (see fig. 4 and 5) is performed to detect the length of the packaged body 10 in the predetermined direction (first direction). The detection step S1 is performed while the package 10 is conveyed on the conveyor 100. In the detecting step S1, the length W1 of the packaged body 10 in the direction perpendicular to the conveying direction P is preferably detected. The detection of the length W1 of the packaged body 10 is performed by the detection unit 104. The detection unit 104 may be constituted by a camera, for example.

Preferably, the length W1 is detected for all the packaged objects 10 that have passed the position of the camera 104 on the conveyor 100. The measured value of the length W1 of the package 10 is stored in a memory of a control unit provided in the manufacturing apparatus. The control unit may calculate an average value of the length W1 of the packaged body 10.

Next, a winding step S2 (see fig. 4 and 6) is performed in which the packaging sheet 12 is wound in a cylindrical shape around the package 10. The winding unit performs the winding step S2 in a state where the package 10 is compressed at least in a second direction (M1 direction in fig. 6) orthogonal to the first direction. The winding unit has at least a compression mechanism 110, a conveyor belt 112, and a pusher 114. The packaged body 10 is conveyed into the holding mechanism 122 by the pusher 114 in a state compressed by the conveyor belt 112 and the compression mechanism 110.

The compression mechanism 110 is configured to be capable of reciprocating in a direction approaching the conveyor belt 112 and a direction separating from the conveyor belt 112 (see arrow M1 in fig. 6). The compression mechanism 110 compresses the object 10 toward the conveyor 112 while the object 10 is being introduced into the holding mechanism 112. The packaged body 10 is stored in the holding mechanism 122 while being compressed. Since the winding step S2 is performed in a state where the package 10 is compressed, the rigidity of the entire package 10 (a predetermined number of absorbent articles) can be made high. This enables the steps S3 to S5 after the winding step S2 to be performed with relatively high accuracy.

The packaging sheet 12 stands by near the entrance of the holding mechanism 122. Accordingly, the package 10 is stored in the holding mechanism 122 and the package sheet 12 is wound. Here, the package sheet 12 is wound around the package body 10 in a cylindrical shape with the open end of the package sheet 12 positioned on the end face of the package body 10 in the first direction. That is, the packaging sheet 12 surrounds the package 10 in a cylindrical shape, and an end of the packaging sheet 12 in the first direction (a direction perpendicular to the paper surface in fig. 6) protrudes from the package 10.

The compression mechanism 110 may have a moving belt that moves with the conveyor belt 112. This makes it possible to easily move the package 10 into the holding mechanism 122 in a state where the package 10 is compressed.

The holding mechanism 122 has a receiving portion 113 that receives the packaged body 10. Preferably, the thickness of the storage portion 113 is 90% or less of the thickness of the packaged body 10 in a natural state. Thus, the packaged body 10 is held in the holding mechanism 122 in a compressed state.

The holding mechanism 122 is configured to be rotatable about a rotation shaft 126. Thereby, the packaged body 10 is sent to the first sealing step S3.

In the first sealing step S3, the end edges 12c of the rolled packaging sheet 12 that overlap each other are heat sealed in a state in which at least the packaged body 10 is compressed (see fig. 7 in particular). This can maintain the compressed state of the packaged body 10 wound with the packaging sheet 12. Accordingly, since the rigidity of the entire package 10 and the package sheet 12 can be improved, the steps S4 and S5 after the first sealing step S3 can be performed with higher accuracy.

Preferably, the heat sealing is performed a plurality of times using the sealing mechanism 128. In the example shown in fig. 6, the end edges 12c of the packaging sheet 12 that overlap each other are heat-sealed three times by three sealing mechanisms 128. The tip end portion of each seal mechanism 128 is movable toward the holding mechanism 122. Thus, the sealing mechanism 128 is configured to be able to press the packaged body 10 in the holding mechanism 122. The sealing mechanism 128 presses the overlapping end edges 12c of the packaging sheet 12 while heating.

After the first sealing step S3, the package 10 is pushed out of the holding mechanism 122 by the push rod 124. The pushed out package 10 is sent to the folding step S4(S41 to S44). Before the folding step S4, the packaging sheet 12 is formed into a tubular shape surrounding the package 10 (see also step S3 in fig. 4).

In the folding step S4, the open end of the packaging sheet 12 is folded along the end faces of a predetermined number of the objects to be packaged 10. First, the side surface portion of the open end of the packaging sheet 12 protruding from the package 10 is folded along the end surface of the package 10 (see steps S41 and S42). Thus, the open end of the packaging sheet 12 is in a state where the upper flap portion 12a and the lower flap portion 12b protrude from the packaged body 10.

Next, while the package object 10 is conveyed, an upper flap folding step S43 in which the upper flap portion 12a is folded so as to extend along the end face of the package object 10, and a lower flap folding step S44 in which the lower flap portion 12b is folded so as to extend along the end face of the package object 10 are performed (see fig. 4, 8, and 9).

Fig. 8 shows a folding unit for folding the upper flap part 12a and the lower flap part 12b at the open end of the wrapping sheet 12. Fig. 9 is a schematic diagram showing the folding steps S43 and S44 using the folding means.

The folding unit may be constituted by a folding plate 140. The folding plate 140 has a first plate portion 141, a second plate portion 142, and a third plate portion 143. The first plate portion 141, the second plate portion 142, and the third plate portion 143 are provided on both sides of the package 10 in a direction orthogonal to the conveying direction P of the package 10.

Each of the first plate portion 141, the second plate portion 142, and the third plate portion 143 is formed of a substantially trapezoidal plate. A slight gap is provided between the first plate 141 and the second plate 142 (see fig. 8). Further, a slight gap is provided between the second plate portion 142 and the third plate portion 143 (see fig. 8).

When the packaged body 10 passes between the pair of first plate portions 141, the upper flap portion 12a and the lower flap portion 12b of the packaging sheet 12 pass respectively above and below the first plate portions 141. When the upper flap portion 12a reaches the second plate portion 142, the upper flap portion 12a is bent downward while passing through the gap between the first plate portion 141 and the second plate portion 142. Thereby, the upper flap portion 12a is bent along the end face of the packed body 10.

Further, when the lower flap portion 12b reaches the third plate portion 143, the lower flap portion 12b is bent while passing through the gap between the second plate portion 142 and the third plate portion 143. Thereby, the lower flap portion 12b is bent along the end surface of the packed body 10.

The folding plate 140 is configured to be movable in the direction M3 so that the interval W2 in the direction M3 orthogonal to the conveying direction P can be changed. Preferably, the manufacturing method according to the present embodiment includes a step of changing the position of the folding plate 140 in the first direction in accordance with the length W1 of the packaged body 10 detected in the detecting step S1. Preferably, when switching from the standby state in which no absorbent article is present in the folding process S4 to the state in which the absorbent article has reached the folding process S4, the position of the folding plate 140 is changed. Preferably, such position control of the folding plate 140 is automatically performed by the apparatus that sequentially manufactures the packages. By changing the position of the folding plate 140 in accordance with the length W1 of the packaged body 10, even if there is fluctuation in the length W1 of the packaged body 10 (absorbent article), the position of the folding plate 140 can be changed in accordance with the length W1 of the packaged body. This makes it possible to fold the packaging sheet 12 with high accuracy from the packaged body 10.

After the folding process S4, a second sealing process S5 is performed using a sealing unit. The sealing unit has

heating mechanisms

150, 152, 160, 164. In the second sealing step S5, the open ends of the packaging sheet 12 folded in the folding step S4 are heat sealed by pressing the

heating mechanisms

150, 152, 160, and 164 against the open ends of the packaging sheet 12.

Specifically, as shown in fig. 10, the sealing unit has

endless belts

154, 162, 166 that rotate together with the conveyance of the packaged body 10. The

endless belts

154, 162, 166 contact both end surfaces of the package 10 in the direction orthogonal to the conveying direction P. The

heating mechanisms

150, 152, 160, and 164 press the package 10 while heating the package 10 via the

endless belts

154, 162, and 166. Thus, the packaging sheet 12 packaging the packaged body 10 is heat-sealed by the

heating mechanisms

150, 152, 160, and 164 while being conveyed. The

heating mechanisms

150, 152, 160, and 164 are provided on both sides of the package 10 in a direction orthogonal to the conveying direction P of the package 10.

The heating mechanism may be provided in plurality. In the present embodiment, the heating mechanism includes, in order from the upstream side: a first heating mechanism 150, a second heating mechanism 152, a third heating mechanism 160, and a fourth heating mechanism 164.

The first heating mechanism 150, the second heating mechanism 152, the third heating mechanism 160, and the fourth heating mechanism 164 are configured to be capable of reciprocating in directions M4, M5, M6, and M7 perpendicular to the conveying direction P of the package 10. The first heating mechanism 150, the second heating mechanism 152, the third heating mechanism 160, and the fourth heating mechanism 164 heat-seal the packaging sheet 12 while pressing both end portions of the package 10 in the direction orthogonal to the conveying direction P.

The manufacturing method according to the present embodiment includes a position control step of changing the position of the first heating means 150 in the first direction (the direction orthogonal to the conveying direction) in accordance with the length W1 of the packaged body 10 detected in the detection step S1 when no absorbent article is present in the second sealing step S5. Specifically, in the position control step, the positions of the pair of first heating mechanisms 150 are controlled such that the interval between the pair of first heating mechanisms 150 is slightly wider than the length W1 of the packaged body 10 measured in the detection step S1. Here, the "length W1 of the packaged body 10" may be defined as an average value of the lengths of a plurality of packaged bodies 10. In this case, the positions of the pair of first heating mechanisms 150 are controlled so that the interval between the pair of first heating mechanisms 150 is wider than the average value by a little.

When no absorbent article is present in the second sealing step S5, the position of the first heating means 150 in the first direction is changed in accordance with the length W1 of the predetermined number of absorbent articles (packaged bodies 10) detected in the detecting step S1. In this way, in the standby state where the second sealing step S5 is stopped, the first heating mechanism 150 can be caused to stand by at an appropriate position in accordance with the size of the package 10. Thus, when the second sealing process S5 is restarted, the first heating mechanism 150 can apply an appropriate pressing force to the absorbent article in accordance with the size of the absorbent article. In particular, there are cases where the size of the absorbent article fluctuates greatly with respect to the design value designed in advance. Even in this case, the second sealing step S5 can be appropriately performed by controlling the position of the first heating means 150 according to the length W1 of the package 10. As a result, even if the size of the absorbent article is smaller than the design value, sufficient heat can be given to the packaging sheet 12, and heat sealing can be performed sufficiently. Further, even if the size of the absorbent article is larger than the design value, since the absorbent article is not given more pressing force than necessary, it is possible to suppress the fear that the thermoplastic material contained in the absorbent article melts.

In addition, it is preferable that the method further includes a pressure control step of controlling the position of the first heating mechanism 150 in the first direction so that the pressure applied from the absorbent article to the first heating mechanism 150 is within a predetermined range when the absorbent article is present in the second sealing step S5. Thereby, even in the case where there is fluctuation in the size of the package 10, the first heating mechanism 150 can give an appropriate pressing force to each package 10 (absorbent article). This makes it possible to heat seal the packaging sheet 12 of the packaged body 10 with higher accuracy.

As an example of the pressure control step, torque control of a motor that drives the first heating means 150 can be cited. By controlling the torque of the motor to be constant, the pressure applied to the package from the first heating means 150 can be controlled to be within a predetermined range. As a result, the packaging sheet 12 for packaging the packaged body 10 can be heat sealed with higher accuracy.

As another example of the pressure control step, a control means may be mentioned which measures the reaction force applied from the absorbent article to the first heating means 150 and feeds back the measured value to the driving of the first heating means 150. Thereby, the pressure applied from the first heating means 150 to the package 10 can be controlled to fall within a predetermined range. As a result, the packaging sheet 12 for packaging the packaged body 10 can be heat sealed with higher accuracy.

In the manufacturing method according to the present embodiment, when the packaged body (absorbent article) 10 is introduced into the second sealing step S5 in the position control step in the second sealing step S5, the position control step is switched to the pressure control step. Preferably, the switching is performed automatically.

Since the first heating mechanism 150 is switched to the pressure control step when the package 10 is introduced into the second sealing step S5, an appropriate pressing force can be applied to the package 10 when the package 10 is heat sealed. Thereby, the absorbent article can be heat sealed with high accuracy.

In the present embodiment, the packaged body 10 is heat-sealed by the first heating means 150 and then further heat-sealed by the second heating means 152. By heat-sealing the packaged body 10 in stages in this manner, heat-sealing can be performed with further high accuracy. In particular, the open end of the packaged sheet 12 folded in the folding step S4 differs in the number of sheets of the packaged sheet 12 that are overlapped in each portion. By heat-sealing in stages, heat-sealing can be sufficiently performed even for portions of a plurality of overlapped packaging sheets 12. Further, since it is not necessary to apply a large amount of heat to the package body 10 and the package sheet 12 at a time, it is possible to reduce the heat damage to the thermoplastic material provided in the absorbent article.

Preferably, the second heating means 152 performs the same pressure control and position control as the first heating means 150.

In the present embodiment, the packaged body 10 is heat-sealed by the second heating means 152, and then is further heat-sealed by the third heating means 160 and the fourth heating means 164. The third heating means 160 and the fourth heating means 164 do not need to perform the pressure control as performed by the first heating means 150.

By completing the second sealing step, the packaged body 10 is sealed by the packaging sheet 12. This makes it possible to produce a package in which an absorbent article having a thermoplastic material is packaged.

While the present invention has been described in detail with reference to the above embodiments, it will be understood by those skilled in the art that the present invention is not limited to the embodiments described in the present specification. The present invention can be implemented by modifications and variations without departing from the spirit and scope of the present invention as set forth in the claims. Therefore, the description of the present specification is for illustrative purposes, and the present invention is not intended to be limited thereto.

The entire contents of Japanese patent application laid-open No. 2015-214304 filed on 30/10/2015 are incorporated into the present specification by reference.

Industrial applicability of the invention

According to the present invention, there is provided an improved method for hermetically sealing an absorbent article having poor heat resistance in which the outer dimensions are likely to vary.

Claims

1. A method of sequentially manufacturing a package in which a predetermined number of absorbent articles having a thermoplastic material are packaged, the method comprising:

a detection step of detecting a length of the predetermined number of absorbent articles in a first direction;

a winding step of winding a wrapping sheet around the predetermined number of absorbent articles in a tubular shape in a state where the entire predetermined number of absorbent articles are compressed at least in a second direction orthogonal to the first direction, such that an open end is positioned at an end face of the predetermined number of absorbent articles in the first direction, that is, an end portion of the wrapping sheet in the first direction protrudes from the end face;

a folding step of folding the open end of the package sheet so as to be along end faces of the predetermined number of absorbent articles;

a sealing step of heat-sealing the open end of the packaging sheet folded in the folding step by pressing a heating mechanism against the open end of the packaging sheet;

a position control step of, when no absorbent article is present in the sealing step, changing a position of the heating means in the first direction in accordance with a length of the predetermined number of absorbent articles detected in the detection step; and

a pressure control step of controlling a position of the heating mechanism in the first direction so that a pressure applied from the absorbent article to the heating mechanism is within a predetermined range when the absorbent article is present in the sealing step.

2. The method of claim 1, wherein the heating mechanism comprises: a first heating mechanism provided upstream in the conveyance direction of the predetermined number of absorbent articles, and a second heating mechanism provided downstream in the conveyance direction of the predetermined number of absorbent articles.

3. The method according to claim 1 or 2, wherein when the absorbent article is introduced into the sealing step in the position control step, the position control step is switched to the pressure control step.

4. The method according to claim 1 or 2, wherein the folding process is performed by folding plates provided on both sides of the absorbent article in the first direction,

the method further includes a step of changing a position of the folding plate, and in the step of changing the position of the folding plate, the position of the folding plate in the first direction is changed in accordance with the length of the predetermined number of absorbent articles detected in the detecting step.

5. The method according to claim 1 or 2, comprising a heat-sealing step of heat-sealing the overlapping end portions of the rolled packaging sheet in a state in which the predetermined number of the entire absorbent articles are compressed at least in the second direction after the winding step.

6. An apparatus for sequentially manufacturing a package in which a predetermined number of absorbent articles having a thermoplastic material are packaged, the apparatus comprising:

a detection unit that detects a length of the prescribed number of absorbent articles in a first direction;

a winding unit that winds a wrapping sheet around the predetermined number of absorbent articles in a tubular shape in a state where the entire predetermined number of absorbent articles are compressed at least in a second direction orthogonal to the first direction, such that an open end is positioned at an end face of the predetermined number of absorbent articles in the first direction, that is, an end portion of the wrapping sheet in the first direction protrudes from the end face;

a folding unit that folds the open end of the package sheet so as to follow end faces of the predetermined number of absorbent articles;

a sealing unit that heat-seals the open end of the packaging sheet by pressing a heating mechanism against the open end of the packaging sheet folded in the folding unit;

a position control unit that changes a position of the heating mechanism in the first direction according to a length of the prescribed number of absorbent articles detected in the detection unit when no absorbent article is present in the sealing unit; and

in the apparatus for sequentially manufacturing a package in which a prescribed number of absorbent articles having thermoplastic material are packaged, the position of the heating mechanism in the first direction is controlled so that the pressure applied from the absorbent articles to the heating mechanism is within a prescribed range when the absorbent articles are present in the sealing unit.