Self-Cleaning Laundry Hanging Surfaces for Dirt Repellence

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Solution Overview

Problem

Laundry hanging means such as clothes lines and drying racks become dirty quickly and require laborious cleaning, and existing solutions like protective covers or housings are costly and inconvenient.

Innovation Solution

The development of self-cleaning and dirt-repellent laundry hanging means with a micro-rough surface structure and hydrophobic properties, inspired by the lotus effect, which uses nanoparticles or self-cleaning fibers to repel dirt and allow water to wash it away.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If laundry hanging means are used in the open air, then they are readily accessible and convenient for use, but they get dirty very quickly and require laborious cleaning

Engineering Contradiction:
Improveconvenience of useVSAvoiddirt accumulation
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent applies the lotus effect by changing the surface parameters of the laundry hanging means through a micro-rough surface structure with hydrophobic particles (nanoparticles with diameter of less than 200 nm, preferably less than 100 nm). This parameter change creates a surface that repels dirt and water, allowing rain to wash away dirt particles automatically, thus maintaining cleanliness while remaining accessible for use.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The laundry hanging means is designed to clean itself through the self-cleaning surface property. When rain falls on the hanging means, the hydrophobic micro-rough surface causes water to bead up and roll off, carrying dirt particles with it. This eliminates the need for manual cleaning while maintaining the convenience of outdoor placement.

Inventive Principle:
Principle #25Self-service

2Object-affected harmful factors

If protective covers or housings are used to protect laundry hanging means from dirt, then the hanging means remain clean, but the device complexity and cost increase

Engineering Contradiction:
Improvedirt protectionVSAvoidprotective construction complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent extracts the protective function from a separate physical cover or housing and integrates it directly into the surface of the laundry hanging means itself. The hydrophobic micro-rough surface layer provides the protective function inherently, eliminating the need for additional protective constructions and reducing device complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The laundry hanging means is provided with a paint coating containing hydrophobic particles (nanoparticles) in the top layer, creating a composite material structure. This composite surface combines the base material with functional particles to achieve dirt-repellent properties without adding complex protective housings.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If a multi-arm spreader frame with automatic clothesline retraction is used, then the clothesline is protected from dirt, but the device complexity and manufacturing cost increase significantly

Engineering Contradiction:
Improveclothesline protectionVSAvoidspreader frame complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of using a complex automatic retraction mechanism, the patent makes the clothesline itself self-cleaning through the hydrophobic micro-rough surface. The clothesline remains exposed and accessible but automatically cleans itself when rain falls, eliminating the need for mechanical retraction systems.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent replaces the mechanical automatic retraction system with a surface property-based solution. Rather than using motors, springs, or complex mechanisms to retract the clothesline, the invention uses the lotus effect surface properties to provide protection, substituting a mechanical system with a material science approach.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Device complexity

If clothespins are removed from the clothesline to allow proper retraction, then the clothesline can be drawn in, but additional user effort and time are required

Engineering Contradiction:
Improveretraction mechanism functionalityVSAvoiduser effort
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The clothesline with hydrophobic surface cleans itself automatically when rain falls, eliminating the need for user intervention to remove clothespins for retraction. The user simply hangs laundry as normal, and the self-cleaning function operates autonomously, reducing user effort and time.

Inventive Principle:
Principle #25Self-service

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

Eliminates the need for frequent cleaning and protective covers, ensuring the hanging means remain clean and safe for use without soiling laundry, simplifying the hanging process and reducing user effort.

Implementation Method 1

the laundry hanging means according to the invention has a hydrophobic surface

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 2

a combination of micro-rough surface structure and hydrophobicity ensures that even small amounts of running water (for example rain) wash away the dirt particles adhering to the surface and clean the surface

Methodology Applied
Scientific EffectLotus effect: Lotus Leaf Effect

Implementation Method 3

a combination of micro-rough surface structure and hydrophobicity ensures that even small amounts of running water (for example rain) wash away the dirt particles adhering to the surface

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 4

The surface of the polymer fibers is preferably hydrophobic and/or microrough in order to achieve a lotus flower-like self-cleaning effect

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 5

achieve a lotus flower-like self-cleaning effect

Methodology Applied
Scientific EffectLotus effect: Lotus Leaf Effect

Data Source

PatentEP1887054B9Device for hanging washing
Publication Date: 2009.08.19 LEIFHEIT
  • EP1887054B9 patent drawingFigure 1
  • EP1887054B9 patent drawingFigure 2

AI summary

Washing suspension (A) exhibiting a self-cleaning and/or dirt removing characteristics, is claimed.