Fabric Dryer Humidity Sensor Method to Prevent Over-Drying Damage

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Solution Overview

Problem

Current drying methods for fabrics are inefficient, leading to over-drying, which damages fabrics, wastes energy, and fails to accurately determine the optimal drying point, resulting in under-dried or over-dried loads.

Innovation Solution

Attaching a humidity sensor to the fabric to measure equilibrium relative humidity, allowing the drying process to stop when the fabric reaches a predetermined level below 80%, using a detachable sensor that communicates with the dryer and provides real-time data to an electronic device.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If drying continues until fabrics are bone-dry, then complete moisture removal is achieved, but fabric damage occurs and energy is wasted

Engineering Contradiction:
Improvemoisture contentVSAvoidfabric damage
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent employs feedback control by continuously monitoring the fabric's moisture content during drying and automatically adjusting or terminating the drying process when the optimal moisture level (4-6% for towels) is reached. This prevents over-drying damage while ensuring complete moisture removal, resolving the contradiction between thorough drying and fabric preservation.

Inventive Principle:
Principle #23Feedback

2Extent of automation

If sensors are placed in the dryer air outlet or on dryer wall, then the drying process can be monitored, but the readings do not accurately represent the fabric's local condition

Engineering Contradiction:
Improvedrying process monitoringVSAvoidfabric dryness measurement
Core Design Contradiction:
Extent of automationVSMeasurement precision

Solution Approach 1:

The patent introduces an intermediary humidity sensor that directly contacts the fabric during drying. This intermediary device provides accurate real-time measurement of the fabric's actual moisture content, bridging the gap between automated monitoring capability and precise measurement requirement, thereby resolving the contradiction between automation extent and measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If drying time is extended to ensure complete dryness, then moisture removal is thorough, but energy consumption increases and fabric quality deteriorates

Engineering Contradiction:
Improvemoisture removalVSAvoidenergy consumption
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The feedback control system monitors moisture content in real-time and terminates drying at the optimal point (4-6% moisture for towels), preventing unnecessary extended drying. This resolves the contradiction by ensuring thorough moisture removal while minimizing energy consumption and avoiding fabric quality deterioration from over-drying.

Inventive Principle:
Principle #23Feedback

4Quantity of substance

If drying continues beyond optimal moisture level, then all moisture is removed, but static charge accumulates and causes greying

Engineering Contradiction:
Improvemoisture contentVSAvoidstatic charge and greying
Core Design Contradiction:
Quantity of substanceVSObject-generated harmful factors

Solution Approach 1:

The feedback control system stops drying at the optimal moisture level (4-6% for towels) before complete bone-dryness is achieved. This prevents static charge accumulation and subsequent greying while still removing sufficient moisture, resolving the contradiction between thorough drying and preventing harmful static effects.

Inventive Principle:
Principle #23Feedback

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 ensures accurate determination of fabric dryness, reduces energy consumption, prevents fabric damage, and maintains fabric quality by stopping the drying process when the fabric reaches the optimal moisture level, thereby extending its longevity and retaining perfume.

Implementation Method 1

measuring the equilibrium relative humidity of the fabric using the humidity sensor

Methodology Applied
Scientific EffectEquilibrium relative humidity measurement: Hygrometer

Implementation Method 2

they do not contain enough water for evaporative cooling to occur and the temperature at the fabric level starts to increase markedly

Methodology Applied
Scientific EffectEvaporative cooling: Evaporative Cooler

Data Source

PatentEP3444396B1Method of drying
Publication Date: 2022.06.29 PROCTER & GAMBLE CO
  • EP3444396B1 patent drawingFigure 1

AI summary

A method of drying a wet fabric in a dryer comprising the steps of; a) attaching a humidity sensor to the fabric; b) placing the fabric in the dryer; c) starting the drying process; d) measuring the equilibrium relative humidity of the fabric using the humidity sensor and e) stopping the drying process when a predetermined level of the equilibrium relative humidity is achieved.