Method for removing stains during a cleaning cycle of a household appliance

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Solution Overview

Problem

Existing cleaning programs in household appliances, such as dishwashers, struggle to efficiently remove persistent stains like tea stains on ceramic cups without using bleach, which can be incompatible with other items and unstable in dosing systems.

Innovation Solution

A method involving the release of a main cleaning agent during the main wash cycle of a household appliance when the temperature exceeds a predetermined threshold (above 40°C), using a cleaning agent that includes at least one chelating agent, along with a first cleaning agent released at lower temperatures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If bleach is used to remove persistent stains like tea stains, then cleaning effectiveness is improved, but compatibility with other items and stability in dosing systems deteriorates

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidcompatibility and stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The patent changes the chemical parameters of the cleaning agent by using chelating agents instead of bleach, and optimizes the temperature parameter by releasing the cleaning agent at temperatures above 40°C to enhance cleaning effectiveness while maintaining compatibility and stability

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses conventional stable cleaning agents that can be stored in dosing systems rather than unstable bleach, accepting that higher temperatures are needed but gaining stability and compatibility benefits

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Manufacturing precision

If very high temperatures (above 70°C) or large amounts of cleaning agents are used, then stain removal effectiveness is improved, but energy consumption and chemical usage increase

Engineering Contradiction:
Improvestain removal effectivenessVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent optimizes the temperature parameter by releasing the cleaning agent at temperatures above 40°C, which is higher than conventional low-temperature dispensing but lower than very high temperatures, achieving effective stain removal while moderating energy consumption

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The cleaning agent is released before the temperature peaks, allowing it to act during the heating phase when temperature is rising above 40°C, optimizing the interaction between temperature and cleaning agent effectiveness

Inventive Principle:
Principle #10Preliminary action

3Duration of action of moving object

If cleaning agents are dispensed early in the main wash cycle at low temperatures, then cleaning agents can act longer, but cleaning effectiveness on persistent stains deteriorates

Engineering Contradiction:
Improvecleaning agent action durationVSAvoidcleaning effectiveness
Core Design Contradiction:
Duration of action of moving objectVSManufacturing precision

Solution Approach 1:

The cleaning agent is released in advance during the main wash cycle at temperatures above 40°C, before the highest temperature phase, allowing it to be present when conditions are optimal for stain removal

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent changes the temperature parameter at which the cleaning agent is released from conventional low temperatures to temperatures above 40°C, fundamentally altering the cleaning mechanism to be temperature-enhanced rather than time-dependent

Inventive Principle:
Principle #35Parameter changes

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 effectively removes persistent stains like tea stains without the need for bleach, using optimized temperature and cleaning agent timing to enhance cleaning efficiency.

Implementation Method 1

the main cleaning agent comprises at least one chelating agent

Methodology Applied
Scientific EffectChelation:

Data Source

PatentEP3883448B1Method for removing stains during a cleaning cycle of a household appliance
Publication Date: 2025.06.18 HENKEL KGAA
  • EP3883448B1 patent drawingFigure 1
  • EP3883448B1 patent drawingFigure 2
  • EP3883448B1 patent drawingFigure 3

AI summary

A method for removing stains, in particular tea stains, during a cleaning cycle of a household appliance, such as a dishwashing machine. The cleaning cycle comprises at least a main wash cycle. A cleaning agent is released during the main wash cycle when the temperature inside the household appliance during the main wash cycle exceeds a predetermined temperature threshold, the threshold being higher than 40°C, for example higher than 55°C.