Embossed Absorbent Paper Anti-Nesting Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in producing absorbent paper sheets with controlled rigidity involves the issue of nesting between embossed plies, which leads to incomplete bonding and high scrap rates during the manufacturing process, especially when embossing patterns result in interlocking protuberances.
Innovation Solution
The solution involves using a sheet composed of at least two embossed plies with elongated protuberances, where the first and second plies have frustoconical protrusions aligned at a non-zero angle, ensuring contact between the plies and preventing nesting, and optionally adding a third ply with similar embossing patterns for enhanced thickness and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If embossed plies are combined in point-to-point position to maximize thickness, then the sheet thickness is improved, but nesting occurs between protuberances causing incomplete bonding and high scrap rates
Solution Approach 1:
The patent applies asymmetry by using embossing patterns with different orientations on adjacent plies. Specifically, the pattern on the second ply is rotated by an angle between 10° and 45° relative to the first ply, preventing the protuberances from aligning and nesting together. This asymmetric arrangement ensures complete bonding coverage while maintaining maximum thickness from point-to-point positioning.
2Ease of manufacture
If embossing patterns use simple geometric shapes for ease of manufacture, then manufacturing complexity is reduced, but the sheet lacks textile appearance and softness
Solution Approach 1:
The patent applies local quality by varying the shape of protuberances within the embossing pattern. Different zones of the pattern contain protuberances with different geometries (circular, oval, polygonal cross-sections), creating localized variations in surface texture. This provides a rich textile appearance and soft hand feel while still using relatively simple embossing techniques that are manufacturable.
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 ensures consistent contact between plies, reducing nesting and enhancing the sheet's thickness, flexibility, and rigidity, resulting in a product with a textile appearance and improved bonding, thus minimizing scrap and achieving a soft yet robust absorbent paper.
Implementation Method 1
By embossing, the sheet is permanently deformed in places, in particular in order to obtain protrusions on one face of the sheet. The embossing makes it possible to increase the thickness of the sheet but also to make it more flexible due to the breaking of interfiber bonds that it entails.
Implementation Method 2
two plies are bonded by passing them through the clamping gap provided between two metal cylinders of identical embossing patterns
Implementation Method 3
two plies are bonded by passing them through the clamping gap provided between two metal cylinders
Data Source
Figure 1~4
AI summary
The present invention relates to a sheet of absorbent paper including at least first (10) and second (20) embossed plies of cellulose wadding, each one of the plies having a grammage of 10 to 40 g/m2 including projections on the inward-facing surface of the sheet which correspond to cavities on the outer surface, with elongate first projections (11) on the first ply, elongate first projections (21) on the second ply, at least one part of the first projections (11) of the first ply being in contact with at least one part of the first projections (21) of the second ply. The sheet is characterised in that the first ply and the second ply (10, 20) each include frustoconical second projections (12; 22), at least one part of the first projections (11; 21) at least partially adjoining the second projections (12; 22), the first projections of said first ply being aligned in a first direction and the first projections of said second ply being aligned in a second direction, the two directions forming a non-zero alpha angle therebetween, at least one part of the second projections (12; 22) forming alignments inserted between two alignments of the first projections (11; 21). The sheet can be used for the production of paper for household or sanitary use.