Manufacturing apparatus and manufacturing method for manufacturing composite sheet associated with absorbent article
A manufacturing apparatus for manufacturing a composite sheet associated with an absorbent article, including: a producing device that produces a substrate sheet by fixing a stretchable sheet to at least low-extensible sheet, the stretchable sheet continuing along a transporting direction, the stretchable sheet being in an extended state in which the stretchable sheet is extended in the transporting direction, the producing is performed while the producing device is transporting the stretchable sheet; a reference-section forming apparatus that forms a physical reference section on the substrate sheet, the substrate sheet being in a first extended state and being transported; a contraction apparatus in which the substrate sheet that has the reference section formed on it contracts until the substrate sheet becomes in a second extended state whose extension ratio is smaller than an extension ratio of the first extended state; and a processing apparatus that performs the certain process to the substrate sheet, the substrate sheet having contracted and being in the second extended state. The contraction apparatus includes: a transport path in which the substrate sheet is transported; a sensor that detects the reference section after the contraction in the contraction apparatus and that outputs a detection signal; and an alteration device that alters a transportation state of the substrate sheet in the transport path so that a position in the substrate sheet for the certain process is located close to a target position for the certain process, the alteration being performed according to the detection signal of the sensor.
1. A manufacturing method for manufacturing a composite sheet associated with an absorbent article,
the manufacturing being performed by producing a substrate sheet and performing a certain process to the substrate sheet,
the substrate sheet including a stretchable sheet and a low-extensible sheet,
the low-extensible sheet having an extensibility lower than that of the stretchable sheet,
the manufacturing method comprising:
producing the substrate sheet by fixing the stretchable sheet to at least the low-extensible sheet,
the stretchable sheet continuing along a transporting direction,
the stretchable sheet being transported,
the stretchable sheet being in an extended state in which the stretchable sheet is extended in the transporting direction;
forming a physical reference section on the substrate sheet,
the substrate sheet being in a first extended state and being transported;
causing the substrate sheet to contract until the substrate sheet becomes in a second extended state whose extension ratio is smaller than an extension ratio of the first extended state,
the substrate sheet having the reference section formed on it; and
performing the certain process to the substrate sheet,
the substrate sheet having contracted and being in the second extended state,
causing the substrate sheet to contract including:
transporting the substrate sheet in a transport path;
detecting the reference section by a sensor and outputting a detection signal by a sensor after the contraction; and
altering a transportation state of the substrate sheet in the transport path so that a position in the substrate sheet for the certain process is located close to a target position for the certain process,
the altering being performed according to the detection signal of the sensor.
2. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein the step of altering a transportation state of the substrate sheet in the transport path comprises:
providing an alteration device that includes a roll whose outer circumferential surface comes into contact with the substrate sheet and that is driven and rotated, and
altering the transportation state of the substrate sheet in the transport path by altering a circumferential speed value of the roll.
3. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 2 , wherein:
the alteration device includes a controller that controls the roll according to the detection signal,
when the detection signal indicates that a target position in a substrate sheet for the certain process is shifted upstream in the transporting direction from a position at which the certain process has been performed by the processing apparatus, the controller increases the circumferential speed value of the roll, and
when the detection signal indicates that the target position in the substrate sheet for the certain process is shifted downstream in the transporting direction from a position at which the certain process has been performed by the processing apparatus, the controller decreases the circumferential speed value of the roll.
4. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein the step of altering a transportation state of the substrate sheet in the transport path comprises:
providing an alteration device includes a roll whose outer circumferential surface comes into contact with the substrate sheet and that is capable of rotating, and
altering the transportation state of the substrate sheet in the transport path by reciprocating motion of the roll along a thickness direction of the substrate sheet.
5. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 3 , wherein:
when the detection signal indicates that a target position in a substrate sheet for the certain process is shifted upstream in the transporting direction from a position at which the certain process has been performed by the processing apparatus, the controller moves the roll in the thickness direction so that a loop of the substrate sheet formed by the roll becomes smaller, and
when the detection signal indicates that the target position in the substrate sheet for the certain process is shifted downstream in the transporting direction from a position at which the certain process has been performed by the processing apparatus, the controller moves the roll in the thickness direction so that a loop of the substrate sheet formed by the roll becomes larger.
6. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein:
the reference section comprises a leg opening of the absorbent article that is formed on the substrate sheet,
the leg opening being aligned at the first pitch and serving as the reference section.
7. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein:
the reference section comprises a mark that is printed on the substrate sheet as the reference section.
8. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 6 , wherein:
the reference section further comprises a mark that is printed on the substrate sheet as the reference section.
9. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 7 , wherein:
the reference section mark is printed on the low-extensible sheet of the substrate sheet.
10. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein:
on the substrate sheet which is in the first extended state, parts each of which is to be the absorbent article are aligned in the transporting direction at a first pitch, and
when a pitch obtained by reducing the first pitch at a ratio of the extension ratio in the second extended state to the extension ratio of the first extended state is defined as a second pitch, the processing apparatus performs the certain process to the substrate sheet at the second pitch.
11. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 9 , wherein:
the absorbent article includes an absorbent main body that absorbs liquid, and
the processing apparatus attaches the absorbent main body to the substrate sheet at the second pitch, the attachment being performed as the certain process.
12. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 9 , wherein:
the substrate sheet that is in the second extended state is configured in a two-folded state in which the substrate sheet is two-folded in a width direction of the substrate sheet, and
in the processing apparatus, the substrate sheet is fixed in the two-folded state by forming a joined part on the substrate sheet at the second pitch,
the forming of the joined part is performed by the processing apparatus as the certain process.
13. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein:
an extension ratio of the substrate sheet in the first extended state remains at an extension ratio in the extended state at a time of the fixing process in the producing device in which the stretchable sheet is fixed to the low-extensible sheet,
the low-extensible sheet when is fixed to the stretchable sheet that is in the extended state is extended and tightened, and
the reference section is formed for each part of the substrate sheet, the part is a part that is to be the absorbent article.
14. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 1 , wherein:
during a time period from the contraction in the contraction apparatus till the certain process, the sensor detects the reference section and outputs the detection signal.
15. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 2 , wherein:
on the substrate sheet which is in the first extended state, parts each of which is to be the absorbent article are aligned in the transporting direction at a first pitch, and
the physical reference section comprises a leg opening of the absorbent article that is formed on the substrate sheet,
the leg opening being aligned at the first pitch and serving as the reference section.
16. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 3 , wherein:
on the substrate sheet which is in the first extended state, parts each of which is to be the absorbent article are aligned in the transporting direction at a first pitch, and
the physical reference section comprises a leg opening of the absorbent article that is formed on the substrate sheet,
the leg opening being aligned at the first pitch and serving as the reference section.
17. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 4 , wherein:
on the substrate sheet which is in the first extended state, parts each of which is to be the absorbent article are aligned in the transporting direction at a first pitch, and
the physical reference section comprises a leg opening of the absorbent article that is formed on the substrate sheet,
the leg opening being aligned at the first pitch and serving as the reference section.
18. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 5 , wherein:
on the substrate sheet which is in the first extended state, parts each of which is to be the absorbent article are aligned in the transporting direction at a first pitch, and
the physical reference section comprises a leg opening of the absorbent article that is formed on the substrate sheet,
the leg opening being aligned at the first pitch and serving as the reference section.
19. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 2 , wherein:
the physical reference section comprises a mark that is formed on the substrate sheet as the reference section.
20. A manufacturing method for manufacturing a composite sheet associated with an absorbent article according to claim 9 , wherein:
the substrate sheet that is in the second extended state is configured in a two-folded state in which the substrate sheet is two-folded in a width direction of the substrate sheet, and
in the processing apparatus produces the absorbent article by cutting the substrate sheet at the second pitch,
the cutting is performed by the processing apparatus as the certain process.