Multi-Ply Tissue With 3D Topography For Interply Absorbency
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Solution Overview
Problem
Current multi-ply tissue products face challenges in achieving enhanced bulk and absorbency without compromising strength, as traditional methods like embossing can degrade product strength and increase costs.
Innovation Solution
The development of multi-ply tissue products with uncreped through-air dried webs featuring 3-dimensional topography, where each ply has raised and depressed areas, and are combined to maximize void space and prevent nesting, using a through-air drying process to maintain non-compressiveness and enhance absorbency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If embossing is used to increase bulk and absorbency in multi-ply tissue products, then bulk and absorbency are improved, but product strength is degraded and manufacturing cost increases
Solution Approach 1:
The invention changes the physical state and structural parameters of the tissue plies by using through-air drying to create a non-compressive drying process. This produces plies with high bulk and porosity without the mechanical compression of traditional embossing, thereby maintaining strength while achieving enhanced absorbency and bulk characteristics.
Solution Approach 2:
The invention utilizes porous material structures created through through-air drying of the tissue plies. The non-compressive drying process creates a highly porous structure with increased void space between fibers, which enhances liquid absorbency and bulk without compromising the structural integrity and strength of the tissue product.
2Quantity of substance
If embossing is used to increase bulk and absorbency, then bulk and absorbency are improved, but manufacturing cost increases due to additional process steps
Solution Approach 1:
The invention merges the drying process with the bulk creation process. By using through-air drying to simultaneously remove moisture and create high-bulk porous structure, the invention eliminates the need for separate embossing operations, thereby reducing manufacturing steps and associated costs while achieving the desired bulk and absorbency improvements.
Solution Approach 2:
The invention changes the drying process parameters from conventional compression-based drying to non-compressive through-air drying. This parameter change allows the drying process itself to create the desired bulk structure, eliminating the need for additional embossing process steps and reducing overall manufacturing complexity and cost.
3Speed
If traditional wet-pressing is used to remove water from the web, then water removal is efficient, but the web becomes compressed and less bulky
Solution Approach 1:
The invention replaces the mechanical compression-based water removal system with a thermal convection system. Instead of using pressure rolls to mechanically squeeze water from the web, the invention uses through-air drying where hot air convection currents remove moisture, thereby avoiding mechanical compression and preserving web bulk while still achieving efficient water removal.
Solution Approach 2:
The invention uses pneumatic principles through through-air drying, where streams of heated air are passed through the tissue web to remove moisture. This pneumatic approach to water removal eliminates the need for mechanical compression, allowing efficient evaporation and water removal while maintaining the web's bulky structure and porosity.
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 resulting tissue products exhibit significantly improved interply absorbency, retaining greater amounts of water and maintaining high absorbency even after peak absorption, with enhanced bulk and strength characteristics.
Implementation Method 1
Throughdrying provides a relatively noncompressive method of removing water from the web by passing hot air through the web until it is dry
Implementation Method 2
passing hot air through the web until it is dry
Implementation Method 3
each ply has raised and depressed areas, and are combined to maximize void space and prevent nesting
Data Source
AI summary
Multi-ply tissue products are disclosed. The multi-ply tissue products contain tissue webs that have raised areas and depressed areas. The tissue webs may be constructed so as to be relatively non-compressive and may have a resilient three-dimensional structure. During production, in one embodiment, the tissue webs may be produced without being subjected to any substantial compression, such as a calendering process. Although not necessary in all applications, in one embodiment, the tissue webs may be combined such that the depressed areas contact each other to form the multi-ply product. The tissue webs, for instance, may comprise a through-air dried web in which the raised areas and the depressed areas are molded into the web. Tissue products made according to the present invention have enhanced absorption characteristics. For instance, the tissue products can have an interply absorbency of greater than about 3 g/g after 30 seconds.