Shear-Thinning Impregnation for Wipe Stacks
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Solution Overview
Problem
Current impregnation technologies for pre-impregnated wet wipes, particularly those with viscous cleaning and care compositions, face challenges in achieving homogeneous distribution across a stack of absorbent supports, leading to inefficient use and storage issues, as traditional methods like spraying or dipping fail to ensure uniform saturation, especially when the liquid is too viscous.
Innovation Solution
A shear-thinning and thixotropic cleaning and care composition with an apparent viscosity greater than 80 centipoise, comprising magnesium aluminum silicate and sodium carboxymethylcellulose, is applied under stress to a stack of absorbent supports, allowing for uniform diffusion and improved impregnation, with a process that involves stacking supports and applying the composition with a Brookfield viscometer-characterized viscosity profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional impregnation methods (spraying or dipping) are used with viscous compositions, then the process is simple, but homogeneous distribution across the stack is not achieved
Solution Approach 1:
The patent applies stress (pressure) to the stack during impregnation to force the viscous composition through all supports. This parameter change (applying mechanical stress) enables homogeneous distribution of high-viscosity compositions that cannot be achieved by passive methods like spraying or dipping alone.
Solution Approach 2:
The composition is applied to the top support first, and then stress is applied to drive it through the entire stack. This preliminary application followed by stress ensures that the composition is distributed uniformly throughout all supports before the impregnation process is complete.
2Adaptability or versatility
If low-viscous liquids are used for impregnation, then homogeneous distribution is achieved, but the range of usable cosmetic products is limited
Solution Approach 1:
By applying stress during impregnation, the patent enables the use of high-viscosity compositions (cosmetic creams, ointments, pastes) that would otherwise be impossible to distribute uniformly. This parameter change expands the adaptable product range while maintaining distribution uniformity through mechanical force.
3Productivity
If fluid compositions are impregnated in a stack, then production efficiency is high, but gradual diffusion over time occurs leading to non-uneven distribution during storage
Solution Approach 1:
Applying stress during impregnation forces the composition through all supports rapidly and uniformly, eliminating the gradual diffusion process that occurs with passive impregnation. This results in stable, uniform distribution that is maintained during storage without further migration or segregation.
4Manufacturing precision
If individual support impregnation is performed, then good impregnation quality is achieved, but production yield and efficiency are significantly reduced
Solution Approach 1:
The patent combines multiple supports into a stack and applies stress to the entire stack simultaneously, forcing the composition through all supports in one operation. This merging approach maintains the quality of individual impregnation while achieving the productivity of batch processing.
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 solution ensures rapid and homogeneous diffusion of the composition throughout the stack, maintaining even distribution over time and enhancing the release rate of the cleaning agent, as demonstrated by increased absorption and release rates in examples, improving the usability and storage stability of pre-impregnated wipes.
Implementation Method 1
A viscous, shear-thinning and thixotropic cleaning and/or care composition
Implementation Method 2
A viscous, shear-thinning and thixotropic cleaning and/or care composition
Implementation Method 3
a stack of absorbent supports
Data Source
AI summary
The invention relates to the use of a cleaning and/or care composition for impregnating a stack of absorbent substrates. The cleaning and/or care composition has a relatively high apparent viscosity, while still having a rheological behaviour of the shear-thinning and thixotropic type, and comprises at least one cleaning and/or care compound. Thus, during impregnation under stress, especially under pressure and with prior stirring, the composition shear-thins sufficiently to allow it to diffuse rapidly and uniformly into stacked substrates.