Multi-Ply Tissue Roll with Peripheral Bonding for Softness
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Solution Overview
Problem
Conventional rolls of bathroom tissue with uniform adhesive bonding lead to stiffening, weakened patterns, and unattractive cuts, compromising flexibility, softness, and tear strength, especially when large patterns are cut at the edges.
Innovation Solution
A new joining scheme where bonding points are moved to the periphery, creating a technical zone for stiffness and a usage zone for softness, with the adhesive covering between 4% and 60% of the sheet's surface area, allowing for embossed patterns in the central zone without edge cuts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If adhesive is deposited uniformly over the whole surface area of the plies, then bonding strength is improved, but the sheet becomes stiff and flexibility is reduced
Solution Approach 1:
The adhesive is applied only in a peripheral zone of each sheet rather than uniformly across the entire surface. This localized bonding approach provides sufficient bonding strength at the edges while leaving the central area free to maintain flexibility and softness, resolving the contradiction between bonding strength and flexibility.
2Shape
If large embossed patterns are used, then appearance is improved, but the patterns are cut by edges causing weakened zones and reduced strength
Solution Approach 1:
The sheet is divided into a peripheral bonding zone and a central usage zone. The embossed patterns are confined to the central usage zone, away from the edges that cause cutting. This segmentation allows large decorative patterns to be used for appearance while preventing them from being cut by lateral edges, maintaining pattern integrity and strength.
3Strength
If adhesive bonding is applied to join plies, then connection strength is improved, but the sheet stiffens and rolling becomes difficult
Solution Approach 1:
Adhesive bonding is applied locally only in the peripheral zone (4%-60% of total surface area) rather than across the entire sheet. This localized approach provides sufficient connection strength to join plies while leaving the majority of the central area free of adhesive, maintaining the sheet's flexibility and ease of rolling.
4Strength
If mechanical crushing is used to join plies, then joining is achieved, but an inside-out effect occurs and liquid penetration is accelerated
Solution Approach 1:
The mechanical crushing joining method is replaced with adhesive bonding applied in the peripheral zone. This substitution eliminates the protrusions and inside-out effects caused by mechanical crushing, while the adhesive provides effective joining. The smooth adhesive-bonded surface also reduces liquid penetration compared to the rough mechanical crushing surface.
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 enhances strength, flexibility, and softness while maintaining a presentable appearance, with a 20% improvement in machine direction strength and 7% in cross-direction strength, and a 23% improvement in flexibility, along with reduced liquid penetration and inside-out effects.
Implementation Method 1
the plies in a multi-ply product made essentially of tissue are joined by applying an adhesive between the said plies
Implementation Method 2
the deposition of the adhesive is associated with the embossing pattern
Data Source
AI summary
A product made of tissue for sanitary or domestic use is aimed in particular at products in rolls such as rolls of bathroom tissue (or sanitary paper) and similar rolls. A roll of fibrous cellulosic product includes a rolled strip of sheets of tissue separated by perforated or pre-cut lines, the individual plies of each sheet being bonded over a peripheral surface area of between 4% and 60% of the total surface area of each sheet.