Co-formed Fibrous Web Structure with Optimized Scrim Filament Allocation
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Solution Overview
Problem
The existing co-forming process for producing wet wipes lacks predictability in the effects of scrim layers on properties such as tensile strength, drape, surface friction, opacity, texture, and feel, making it difficult to identify optimal proportions and allocations of components in fibrous web structures for desirable wet wipe substrates.
Innovation Solution
A fibrous web structure with specific allocations of meltblown polypropylene filaments between core and scrim layers is developed, where the weight fraction of pulp fibers ranges from 60% to 90% and meltblown filaments from 10% to 40%, with a predictive model indicating optimal consumer preference within a narrow band of meltblown filament allocation to the scrim layers, enhancing tensile strength, opacity, and consumer preference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If meltblown filaments are allocated to scrim layers in the co-formed fibrous web structure, then tensile strength and opacity are improved, but the predictability of surface friction, texture, and feel deteriorates
Solution Approach 1:
The patent applies local quality by allocating meltblown filaments specifically to scrim layers rather than uniformly distributing them throughout the web structure. This localized allocation enhances tensile strength and opacity at the surface level while maintaining control over surface friction and texture through defined filaments-per-inch ranges (5-20 filaments per inch), thereby resolving the contradiction between strength improvement and predictability maintenance.
2Strength
If more material is used in the fibrous web structure, then structural integrity and tensile strength are improved, but cost and environmental sustainability worsen
Solution Approach 1:
The patent employs parameter changes by optimizing the concentration and distribution of meltblown filaments within specific ranges (5-20 filaments per inch in scrim layers, 10-40% of total web weight as meltblown filaments). This precise parameter control achieves the necessary structural integrity and tensile strength while minimizing material usage, thereby addressing the contradiction between strength improvement and material quantity reduction for cost and sustainability benefits.
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 optimized fibrous web structure achieves improved tensile strength, opacity, and consumer preference by reallocating meltblown filaments from the core to the scrim layers, resulting in a product that balances strength, flexibility, and tactile feel, while maintaining absorbency and structural integrity.
Implementation Method 1
a co-formed fibrous web structure comprising a middle layer formed in a co-forming process of depositing and entangling a blend of filaments and fibers onto a moving forming belt
Implementation Method 2
directing an air stream with entrained distributed cellulose fibers together with the filaments, typically into a co-forming box or similar blending apparatus, blending the filaments and fibers, and directing the blend along to a collecting/forming structure
Implementation Method 3
Upon subsequent consolidation and bonding of the batt, a cohesive fibrous web structure may be formed
Data Source
Figure 1~2
Figure 3
Figure 4~6A
AI summary
An enhanced, co-formed fibrous web structure is disclosed. The web structure may have a co-formed core layer sandwiched between two scrim layers. The core layer may be formed of a blend of cellulose pulp fibers and melt spun filaments. The scrim layers may be formed of melt spun filaments. Filaments of one or both of the scrim layers, and optionally the core layer, may also be meltblown filaments. The fibrous web structure may have a Consumer Preference Indication (governing allocation of melt spun filaments between core layer and scrim layers) greater than 0. Alternatively, the filaments forming the scrim layers may constitute from 1 to 13 percent of the weight of the structure. Alternatively, the scrim layers may have a combined basis weight of from 0.1 gsm to less than 3.0 gsm. A method for forming the structure, including direct formation of layers, is also disclosed.