Tissue Softness Evaluation via Acoustic Emission Analysis
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Solution Overview
Problem
Current methods for determining the softness of tissue paper are subjective and lack a practical, quantitative measure, making it difficult to assess and compare different products, especially in real-time production or quality control settings.
Innovation Solution
A method involving mechanical application of compressive and tensile forces to tissue paper samples to record sound waves, which are then analyzed using pattern recognition techniques, such as hidden Markov models, to objectively assign softness classes, allowing for automated reproduction of human judgments.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a panel test with multiple human testers is used to evaluate softness, then the evaluation can be performed, but it requires a large number of testers and cannot be done continuously or in real-time
Solution Approach 1:
The patent replaces the mechanical human tactile evaluation system with an acoustic measurement system. A mechanical testing device applies standardized forces to the tissue paper sample, and acoustic sensors detect the resulting sound signals. The sound spectrum characteristics are then analyzed to determine softness, substituting human sensory-mechanical evaluation with an automated acoustic-field-based system that enables continuous high-speed testing.
2Measurement precision
If multiple different measuring devices are used to determine various parameters (tensile strength, shear strength, flexural rigidity, etc.), then a comprehensive assessment can be made, but the equipment complexity and measurement time become considerable
Solution Approach 1:
The patent creates a universal acoustic measurement system that can evaluate softness without requiring multiple specialized measuring devices for different mechanical properties. The single acoustic sensing system, combined with standardized mechanical testing, provides comprehensive softness assessment by analyzing sound spectrum characteristics, replacing the need for separate devices for tensile strength, shear strength, flexural rigidity, and other parameter measurements.
Solution Approach 2:
The patent merges multiple measurement functions into a single integrated system. The mechanical testing device applies standardized forces while acoustic sensors simultaneously capture sound signals. The evaluation process combines mechanical forcing with acoustic detection and spectral analysis into one unified measurement approach, consolidating what would otherwise require multiple separate testing devices and procedures.
3Ease of manufacture
If subjective panel tests are used to assign softness classes, then softness evaluation can be performed, but the results are subjectively influenced and cannot be reliably compared across different manufacturers
Solution Approach 1:
The patent replaces the subjective human sensory system with an objective acoustic measurement and analysis system. Instead of relying on human testers' subjective perceptions and interpretations, the system uses acoustic sensors to objectively detect sound signals generated during standardized mechanical testing. The sound spectrum analysis provides quantifiable, reproducible data that eliminates subjective influence and enables reliable cross-manufacturer comparisons.
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
Enables a simple, significant, and objective determination of tissue paper softness, reducing the need for large numbers of human testers and enabling continuous quality control and comparison across different products.
Implementation Method 1
Sound waves emitted as a result are recorded with at least one detector
Data Source
Figure 1
AI summary
The invention relates to a method for determining the softness of tissue paper. The above can be so-called hygienic papers, such as for example tissues, cosmetic towels, kitchen towels, towels or toilet paper. In the method according to the invention, samples of tissue papers are subjected mechanically to pressure forces and/or tensile forces with respectively the same parameters. Sound waves emitted thereby are detected by at least one detector and the thus captured measuring signals are then subjected to a pattern recognition.