Continuous Web Folding Device for Absorbent Articles
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing continuous web processing devices face instability in superimposing the front and rear waistline portions due to varying forces exerted during the folding of continuous webs with alternating leg-hole openings, leading to quality issues in disposable worn articles like diapers, such as displacement of elastic members and discomfort due to improper edge alignment.
Innovation Solution
A continuous web processing device with a folding base unit that changes the conveyance direction and a folding unit comprising a central guiding unit and side guiding units, which superimpose the front and rear waistline portions while maintaining contact with the crotch portion, ensuring stable alignment through a superimposing roller that adjusts the conveyance direction and uses an automatic positioning mechanism to correct misalignments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the continuous web is folded in two by superimposing the front waistline portion and the rear waistline portion based on a part which turns into the crotch portion, then the manufacturing process can be simplified and continuous production can be achieved, but the superimposition becomes unstable due to varying forces exerted by alternating crotch portions with leg-hole openings
Solution Approach 1:
The guiding units are divided into a central guiding unit and a pair of side guiding units, which segment the guiding function to different locations along the web. This segmentation allows independent control of the folding process at different stages, maintaining stability despite the alternating presence of crotch portions with leg-hole openings.
Solution Approach 2:
The guiding units act as intermediary elements that mediate between the alternating crotch portions and the superimposition process. By providing continuous guidance through these intermediary structures, the varying forces from alternating crotch portions are compensated, ensuring stable superimposition throughout continuous production.
2Productivity
If the continuous web is folded while being conveyed, then efficient continuous processing is achieved, but the force exerted to pull the waistline portions toward the crotch portion changes greatly based on the presence or absence of crotch portions, causing elastic members to displace from predetermined positions
Solution Approach 1:
The guiding units are positioned to perform preliminary guiding actions on the web before the actual superimposition occurs. The central guiding unit establishes the fold line early in the process, and the side guiding units maintain alignment as the web progresses, preventing elastic member displacement before it can occur during the final superimposition.
Solution Approach 2:
The guiding units are configured to dynamically adapt to the alternating crotch portions with leg-hole openings. The spacing and positioning of the guiding units allow them to accommodate the varying forces and geometry of alternating crotch portions while maintaining consistent guidance, ensuring elastic members remain at predetermined positions throughout the continuous folding process.
3Ease of manufacture
If the continuous web is folded by superimposing waistline portions based on crotch portions, then the process can be simplified, but edge alignment between front and rear waistline portions becomes inaccurate, causing edges to contact the skin and give discomfort
Solution Approach 1:
The guiding function is segmented into multiple units positioned at different locations: the central guiding unit establishes the fold line, while the side guiding units maintain edge alignment. This segmentation of the guiding function allows simple folding geometry to be combined with precise edge alignment control throughout the continuous web.
Data Source
AI summary
A continuous web processing device including a folding unit that extends in a conveyance direction. The folding unit has a central guide that comes into contact with the bottom of the crotch part of an absorbent article being processed, a pair of side guides that come into contact with the front waistline portion and the rear waistline portion of the absorbent article, and a superimposing roller that superimposes the front waistline portion and the rear waistline portion one on the other. A spacing between the pair of side guides becomes narrower in the downstream conveyance direction. Ends of the side guides are located further upstream than an end of the central guide. The superimposing roller superimposes the front waistline portion and the rear waistline portion of the absorbent article one on the other downstream from the side guides.