Turbidity Measurement for Rinse End Point Detection

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Solution Overview

Problem

Existing methods for determining the rinse properties of compositions, such as shampoos and conditioners, are inaccurate and unreliable due to sensitivity to water temperature, flow rate, and operator variability, making it difficult to assess when a composition is fully rinsed from the hair surface.

Innovation Solution

Measuring the turbidity of rinse water until it reaches a constant level, indicating that no further composition is being removed, provides a reliable and accessible method to determine the end point of rinsing and compare the rinse properties of different compositions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If foam tracking methods are used to measure rinsing properties, then the measurement process is simple and accessible, but the measurement precision and reliability deteriorate due to sensitivity to water temperature, flow rate, time, and operator variability

Engineering Contradiction:

Improvesimplicity of measurement processVSAvoidaccuracy of rinsing property measurement

Core Design Contradiction:

Ease of operationVSMeasurement precision

Solution Approach 1:

The patent replaces the mechanical/visual foam tracking method with an optical measurement system using a turbidimeter. Instead of visually assessing foam volume and disappearance, the system measures the turbidity (optical property) of rinse water to objectively determine composition removal from hair. This substitution of measurement principle eliminates operator variability and improves precision while maintaining operational simplicity.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the measurement parameter from foam volume (which is sensitive to temperature, flow rate, and time) to turbidity of rinse water. Turbidity provides a more stable and reliable parameter that directly correlates with composition concentration in rinse water, reducing sensitivity to environmental variables and improving measurement consistency.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If foam volume is used to assess rinsing properties, then the method is easy to perform, but the reliability deteriorates due to visual assessment variability among different operators

Engineering Contradiction:

Improveease of foam assessmentVSAvoidconsistency of measurement across operators

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent replaces subjective visual assessment with an objective optical instrument (turbidimeter) that measures turbidity of rinse water. This eliminates the variability introduced by different operators' visual judgments while maintaining the simplicity of the overall measurement process. The instrument provides consistent, quantifiable data regardless of which operator performs the measurement.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Measurement precision

If repeated rinsing measurements are performed to determine end point, then the accuracy of determining when composition is fully rinsed improves, but the time and water consumption increase

Engineering Contradiction:

Improveaccuracy of end point determinationVSAvoidtime for repeated rinsing measurements

Core Design Contradiction:

Measurement precisionVSLoss of time

Solution Approach 1:

The patent replaces repeated manual rinsing and visual inspection with a single or few turbidity measurements of collected rinse water. The turbidimeter provides immediate, quantitative data about composition concentration, allowing rapid determination of the rinse end point without requiring multiple rinsing cycles and extended observation time.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 method allows for accurate and reproducible assessment of rinse properties, enabling the determination of when a composition is fully rinsed and comparing the rinse efficiency of different formulations, thereby optimizing water usage and product performance.

Implementation Method 1

measuring the turbidity of the collected rinse water

Methodology Applied

Scientific EffectTurbidity measurement: Scattering

Data Source

PatentUS12140539B2Method for determining rinse properties

Publication Date: 2024.11.12 CONOPCO INC

AI summary

A method of measuring rinse properties of a composition from a surface, the method includes providing a cosmetic treatment composition. The method also includes applying the cosmetic treatment composition to a surface. The method also includes rinsing the surface with a first amount of water after applying the cosmetic treatment composition to the surface. The method also includes collecting a portion of the first amount of water after rinsing the surface with the first amount of water. The method also includes measuring a first turbidity of the portion of the first amount of water after collecting the portion of the first amount of water.