Microperforated Topsheet Structure for Softness and One-Way Permeability
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Solution Overview
Problem
Existing hygiene/sanitary products face challenges in achieving a balance between high softness and unidirectional permeability in their topsheets, with existing solutions often failing to provide an optimal compromise.
Innovation Solution
A multi-layered material comprising a microperforated plastic film layer and a non-woven fabric layer, formed through a process using counter-rotating rollers to create recessed areas with holes and embossed areas, ensuring optimal softness and permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a non-woven fabric is made through-perforated to ensure high unidirectional permeability, then liquid absorption capability is improved, but the softness and pleasant feeling to the touch deteriorates
Solution Approach 1:
The patent applies local quality by creating two distinct types of areas on the non-woven fabric surface: first areas with through holes for permeability and second areas without holes that are embossed and thicker for softness. This spatial differentiation allows different regions to serve different functions - the perforated areas enable liquid passage while the embossed areas provide skin-friendly softness, resolving the contradiction between permeability and comfort.
2Object-affected harmful factors
If the top-sheet is made thicker and softer through embossing, then the pleasant feeling to the touch is improved, but the unidirectional permeability deteriorates
Solution Approach 1:
The patent segments the top-sheet into functionally distinct first areas and second areas. The first areas contain through holes that extend through the entire thickness to ensure unidirectional permeability, while the second areas are embossed and thicker to provide softness. This segmentation allows the sheet to simultaneously achieve both permeability and softness without compromising either function.
3Ease of manufacture
If a single-layer non-woven fabric is used, then the manufacturing process is simple, but the optimal compromise between softness and permeability cannot be achieved
Solution Approach 1:
The patent changes the structural parameters of the non-woven fabric by creating a multi-area configuration with varying thickness and porosity. By controlling the distribution of first areas (perforated) and second areas (embossed), the invention achieves optimal performance compromise between softness and permeability while maintaining a relatively simple single-step manufacturing process using patterned rollers.
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
The multi-layered material achieves a high level of softness and pleasant tactile sensation while maintaining effective unidirectional liquid permeability, improving upon single-layer non-woven fabric solutions.
Implementation Method 1
a first shaping and piercing station comprising a pair of counter-rotating rollers, each roller having an outer cylindrical surface, wherein the rollers are pressed radially towards each other and, immediately before, define an inlet towards which at least two bands or sheets are fed
Implementation Method 2
the rollers rotate at different speeds so that, during their pressing towards each other, sliding occurs between said rollers and the sheets advancing between said rollers
Implementation Method 3
at least one of said rollers is heated so that the sheets are bonded to each other by lamination by the rollers
Data Source
Figure 1~2
Figure 3~6
Figure 7~8
AI summary
A multi-layered material (1), in particular for hygiene/ sanitary products, has an outer surface (2) shaped so as to have a plurality of recessed areas (17) and at least one embossed area (19) which is arranged alongside the recessed areas (17) and protrudes with respect to the recessed areas (17) so as to define a thickness greater than the one at the recessed areas (17); each of the recessed areas (17) has a plurality of through holes (18); the multi-layered material has a first and a second layer (21,22), whereby the through holes (18) pass through both said layers (21,22); the second layer (22) is a non-woven fabric, while the first layer (21) defines the outer surface (2) of the multi-layered material (1) and is a plastic film having a plurality of protruding micro-portions (35) that are provided at least at the embossed area (19) and protrude outwards from the remaining part of the first layer (21) along said outer surface (2).