Laundry Drum Foam Seal Coating for Low-Friction Leak Prevention

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Solution Overview

Problem

Existing laundry treatment machines face issues with high friction between foam seals and laundry drums, leading to significant friction losses and leakage, which can result in poor drying performance and potential damage to electronic components due to moisture ingress.

Innovation Solution

The use of an open-pore foam seal with a Teflon-impregnated sliding surface and an air- and/or water-impermeable coating on at least one circular end face, reducing friction and preventing leakage by minimizing compressive strength and ensuring effective sealing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a closed-cell foam seal is used to prevent air and water leakage, then sealing performance is improved, but friction between the seal and laundry drum increases

Engineering Contradiction:
Improvesealing performanceVSAvoidfriction losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The foam seal is designed with heterogeneous structure: the radially inner lateral surface uses open-pore foam for low friction, while the axially facing surfaces use air- and water-impermeable coating for sealing. This local differentiation allows each surface to optimize for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The foam seal combines two types of foam structures (open-pore and closed-cell) and incorporates an air- and water-impermeable coating to create a composite sealing element that simultaneously achieves low friction and effective sealing.

Inventive Principle:
Principle #40Composite materials

2Loss of energy

If an open-pore foam seal is used to reduce friction, then friction losses are reduced, but air and water leakage occurs

Engineering Contradiction:
Improvefriction lossesVSAvoidsealing performance
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The foam seal is designed with heterogeneous structure: the radially inner lateral surface uses open-pore foam for low friction, while the axially facing surfaces use air- and water-impermeable coating for sealing. This local differentiation allows each surface to optimize for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The foam seal combines two types of foam structures (open-pore and closed-cell) and incorporates an air- and water-impermeable coating to create a composite sealing element that simultaneously achieves low friction and effective sealing.

Inventive Principle:
Principle #40Composite materials

3Reliability

If the compressive strength of the foam seal is increased to improve sealing, then sealing performance is improved, but friction between the seal and laundry drum increases

Engineering Contradiction:
Improvesealing performanceVSAvoidfriction losses
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The foam seal is designed with heterogeneous structure: the radially inner lateral surface uses open-pore foam for low friction, while the axially facing surfaces use air- and water-impermeable coating for sealing. This local differentiation allows each surface to optimize for its specific function.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The foam seal combines two types of foam structures (open-pore and closed-cell) and incorporates an air- and water-impermeable coating to create a composite sealing element that simultaneously achieves low friction and effective sealing.

Inventive Principle:
Principle #40Composite materials

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 solution reduces friction between the foam seal and the laundry drum while maintaining effective sealing, preventing moisture and air leaks, thus enhancing drying performance and protecting internal components from moisture damage.

Implementation Method 1

the sliding surface is made of a Teflon-impregnated felt

Methodology Applied
Scientific EffectFriction reduction through Teflon impregnation: Lubrication

Implementation Method 2

an air- and / or water-impermeable coating being provided on at least one of its circular end faces

Methodology Applied
Scientific EffectPermeation barrier: Permeation

Data Source

PatentEP2850239B1Laundry treatment machine
Publication Date: 2016.04.06 BSH HAUSGERATE GMBH
  • EP2850239B1 patent drawingFigure 1
  • EP2850239B1 patent drawingFigure 2

AI summary

A laundry treatment machine 1 has a laundry drum 3 which is rotatably mounted about a drum axis 3a in a housing 2. An annular foam material seal 11, 14 is arranged between a circumferential part of the laundry drum 3, which rotates during operation of the laundry treatment machine 1, and a stationary surface of a component of the housing 2, the foam material seal being secured to the surface of the component and being sealingly guided on the laundry drum 3. In order to reduce friction between the foam material seal 11, 14 and the laundry drum 3, the foam material seal 11, 14 should be produced from open-cell foam and be arranged over a slide surface 16 on an abutment surface of the circumferential part of the laundry drum 3. Furthermore the annular foam material seal 11, 14 should be provided with an air and/or water proof coating 21, 22 on at least one of its annular front surfaces 19, 20.