Adhesive-Free Elastic Cuff Manufacturing by Thermal Bonding
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Solution Overview
Problem
Existing methods for manufacturing cuffs in worn articles, such as disposable diapers, often require adhesives, which can lead to issues like breakage of elastic members during the heat bonding process, and there is a need for an adhesive-free method that prevents such breakage.
Innovation Solution
A method involving thermal bonding of two sheets with continuous elastic members sandwiched between them, where the sheets are intermittently bonded and then slit to form cuffs, ensuring the elastic members are securely fixed without adhesives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is used to bond sheets and elastic members, then bonding strength is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The patent removes adhesive from the manufacturing process entirely, using only thermal bonding to attach elastic members to sheets. This extraction of the adhesive component simplifies the manufacturing process while maintaining bonding strength through direct thermal fusion of the sheets with the elastic members embedded between them.
Solution Approach 2:
The patent replaces the chemical bonding mechanism (adhesive) with a thermal bonding mechanism. By applying heat and pressure directly to the sheets with elastic members positioned between them, the material itself becomes the bonding agent, eliminating the need for separate adhesive materials and application processes.
2Loss of substance
If edge portion is folded back and thermally bonded, then adhesive use is reduced, but elastic members may break during heat bonding
Solution Approach 1:
The patent positions the elastic members between the sheets before applying thermal bonding. This preliminary placement ensures that the elastic members are securely held in position during the bonding process, preventing breakage while achieving adhesive-free construction. The sheets are thermally bonded around the pre-positioned elastic members rather than folding edges over them.
3Ease of operation
If continuous elastic members are sandwiched between separate sheets, then introduction ease is improved, but thermal bonding may cause breakage
Solution Approach 1:
The patent uses thermal bonding instead of mechanical folding to secure elastic members between sheets. The thermal bonding process applies controlled heat and pressure that fuses the sheets together around the elastic members without the mechanical stress of folding, thereby preventing breakage while maintaining ease of introduction.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method allows for the production of cuffs without adhesives, preventing elastic member breakage and ensuring a comfortable, secure fit by maintaining the elastic properties of the cuffs.
Implementation Method 1
a step of thermally-bonding together the first sheet S1 and the second sheet S2 intermittently in the longitudinal direction Y to form thermally-bonded portions H, thereby fixing the at least two continuous elastic members F to the sheets S1, S2
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
The present cuff manufacturing method includes: a step of sandwiching at least two continuous elastic members F between a first sheet and a second sheet; a step of thermally-bonding together the first sheet and the second sheet intermittently in the longitudinal direction to form thermally-bonded portions, thereby fixing the continuous elastic members, thus forming a laminate; a slit step of slitting the laminate along the longitudinal direction, thereby obtaining a pair of cuff members; a step of conveying the pair of cuff members so that a pair of edges, which have been produced by the slitting in the pair of cuff members, are spaced apart from each other; and a step of arranging the pair of cuff members on opposite edge portions of a crotch portion of a worn article, thereby forming cuffs.