Rotary Embossing and Non-Contact Adhesive for Absorbent Articles
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Solution Overview
Problem
Existing methods for embossing absorbent articles, such as feminine sanitary napkins, face challenges in creating deep channel embossments without damaging the backsheet and ensuring proper adhesive application, leading to issues like adhesive bridging valleys, poor transfer, and unwanted adhesive residue.
Innovation Solution
A method involving a rotary embossing process that forms embossment regions on the topsheet and depression regions on the absorbent core before attaching the backsheet, followed by non-contact adhesive application using a die means that impinges air to deposit adhesive evenly on the backsheet, ensuring it adheres to the release paper without stringing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If deep channel embossments are formed by traditional rotary embossing, then improved fit and fluid barrier are achieved, but the backsheet is damaged through cutting or tearing
Solution Approach 1:
The backsheet is attached to the absorbent core AFTER the embossment is formed, rather than before. This preliminary sequencing allows the embossment to be created at full depth on the topsheet and absorbent core without the backsheet being present to interfere with or damage during the embossing process.
Solution Approach 2:
The conventional sequence is inverted: instead of attaching the backsheet before embossing, the invention attaches the backsheet after embossing. This reversal eliminates the conflict between deep embossing and backsheet protection.
2Manufacturing precision
If adhesive is applied to release paper before attachment to backsheet, then adhesive transfer is intended, but adhesive bridges valleys and does not contact the backsheet properly
Solution Approach 1:
The release paper is completely removed from the final product. Instead of using release paper with adhesive applied to it, the invention applies adhesive directly to the backsheet surface, eliminating the intermediary that causes adhesive bridging and poor contact.
Solution Approach 2:
The invention eliminates the release paper as an intermediary between the adhesive and the backsheet. Adhesive is applied directly to the backsheet surface, ensuring proper contact without the bridging problem caused by release paper valleys.
3Manufacturing precision
If adhesive is applied directly to the backsheet, then adhesive contact is improved, but adhesive is not applied to valleys formed by embossments
Solution Approach 1:
The adhesive application system is designed to deposit adhesive uniformly across the backsheet surface, including into the valleys created by embossments. The local quality of adhesive application is controlled to ensure adequate coverage in both raised and recessed areas.
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 approach allows for deeper embossments without backsheet damage and improves adhesive transfer and peel force consistency, reducing residue on the release paper and enhancing user experience by ensuring the adhesive remains on the absorbent article.
Implementation Method 1
impinging a flow of air from the extrusion outlet at an angle unto the extruding adhesive
Data Source
AI summary
A method for attaching a release paper to a backsheet having depressed regions.