Cross-linked Cellulosic Fibers for Lint Reduction in Tissue
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Solution Overview
Problem
Existing disposable sanitary and facial tissue products face challenges in achieving softness and strength while minimizing lint, as methods to reduce lint often compromise on softness or increase production costs.
Innovation Solution
The process involves using cross-linked cellulosic fibers as a percentage of the overall furnish mix, specifically blending cross-linked fibers into the outward-facing layers of a multilayered tissue product, which are produced using a wet-laid paper process with structuring fabrics like TAD or UCTAD, to create a soft and strong tissue with reduced lint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If chemical debonding agents or softeners are used to increase softness, then softness is improved, but lint levels increase
Solution Approach 1:
A cross-linking agent is introduced as an intermediary substance that forms bridges between cellulose fibers. This mediator strengthens fiber-to-fiber bonds without requiring chemical debonding agents, thereby maintaining fiber integrity and reducing lint while still achieving softness through controlled fiber bonding
Solution Approach 2:
The invention changes the chemical parameters of the fiber network by introducing cross-linking reactions. This modifies the bonding mechanism from hydrogen bonding (which requires debonding for softness) to covalent cross-links (which provide both strength and softness), fundamentally altering the relationship between softness and lint generation
2Ease of operation
If creping is used to create surface nap and increase softness, then softness is improved, but lint levels increase
Solution Approach 1:
Cross-linking is performed as a preliminary action before the creping process. By pre-establishing strong fiber bonds through cross-linking, the subsequent creping operation can create surface nap and softness without excessive fiber liberation, as the cross-linked network prevents individual fibers from detaching during the mechanical creping process
3Ease of operation
If multi-layered tissue structure with debonded outer layers is used to enhance softness, then softness is improved, but lint levels increase
Solution Approach 1:
The invention applies cross-linking locally to specific layers or regions of the multi-layered tissue structure. By selectively cross-linking fibers in outer layers that will face the user, softness is enhanced at the surface while maintaining fiber integrity, reducing lint generation from debonded fibers in those same layers
4Object-generated harmful factors
If chemical strength agents or binders are added to reduce lint, then lint is reduced, but softness decreases
Solution Approach 1:
The invention replaces mechanical and chemical binding systems (strength agents, binders, adhesives) with a self-cross-linking chemical system. Cellulose fibers naturally cross-link through controlled chemical reactions, eliminating the need for external binding agents that would compromise softness, while still achieving lint reduction through strengthened fiber bonds
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 results in a tissue product that is both soft and strong, with significantly reduced lint levels, improving user experience and operational efficiency by minimizing fiber liberation during use.
Implementation Method 1
cross-linked cellulosic fibers as a percentage of the overall furnish mix
Data Source
AI summary
A method of making a tissue or paper towel product including forming two or more multi-layered webs of cellulosic fibers by a papermaking process using a structured fabric, the papermaking process comprising a step of adding a cross-linker to a pulp slurry comprising the cellulosic fibers so that at least some of the cellulosic fibers are cross-linked within the pulp slurry, and laminating the two or more multi-layered webs together so as to form a multi-ply product, each ply of the multi-ply product comprising cross-linked fibers as a percentage of the total fiber mix of the ply.