Frustoconical Polyurethane Seal for Screening Machine

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Solution Overview

Problem

Existing flexible sealing parts for screening machines have a short service life due to material settlement and wear from relative movement and material deposition, which compromises sealing integrity.

Innovation Solution

A flexible sealing part made of elastic polyurethane with a harder flange and softer frustoconical wall, featuring annular stepped folds or steps to prevent material lodging, and a molded polyurethane ring for secure attachment, ensuring high sealing efficiency and longevity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a rubber bellows is used to seal the opening for the shower pipe, then flexibility to absorb relative movement is achieved, but material settles in the folds and causes early destruction

Engineering Contradiction:
ImproveflexibilityVSAvoidservice life
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The sealing part uses a frustoconical shape with a continuously curved surface that tapers outwardly from the flange to the sealing part end. This curved geometry eliminates folds and crevices where material could settle, while still providing the flexibility needed to absorb relative movement between the oscillating screening machine and static spraying machine.

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The sealing part is made from elastic material, preferably polyurethane, forming a flexible hollow structure that can deform to accommodate relative movement. The frustoconical wall tapers outwardly to prevent material settlement while maintaining the flexibility characteristic of thin-walled elastic structures.

Inventive Principle:
Principle #30Flexible shells and thin films

2Adaptability or versatility

If the flange is made of soft polyurethane to match the wall, then flexibility is maintained, but the hold in the opening is not secure and wear is greater

Engineering Contradiction:
ImproveflexibilityVSAvoidhold security
Core Design Contradiction:
Adaptability or versatilityVSStrength

Solution Approach 1:

The sealing part features non-uniform material properties: the flange is made of harder polyurethane (Shore A hardness 60-100, particularly approx. 95) to provide secure holding and resistance to wear in the opening, while the frustoconical wall is made of softer polyurethane (Shore A hardness 35-55, particularly approx. 45) to maintain flexibility. This local differentiation of material properties optimizes each region for its specific function.

Inventive Principle:
Principle #3Local quality

3Ease of manufacture

If the sealing part has a uniform hardness throughout, then manufacturing is simpler, but the flange cannot provide secure hold and the wall cannot provide flexibility

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidsealing performance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sealing part is constructed as a composite structure with two different polyurethane materials having different hardness values. The flange region uses harder polyurethane (Shore A 60-100) while the frustoconical wall uses softer polyurethane (Shore A 35-55), creating a multi-material component that simultaneously achieves secure holding capability and flexibility.

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

The solution provides a long-lasting, flexible seal with enhanced material flow prevention and secure attachment, maintaining high tightness and flexibility, thus extending the service life of the sealing part.

Implementation Method 1

the sealing part is made of an elastic material, preferably polyurethane

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the polyurethane of the flange has a greater hardness than the polyurethane of the frustoconical wall

Methodology Applied
Scientific EffectHardness: Shore Durometer

Data Source

PatentEP2594344B1Side wall seal of a screening machine
Publication Date: 2014.04.30 ISENMANN SIEBE
  • EP2594344B1 patent drawingFigure 1
  • EP2594344B1 patent drawingFigure 2

AI summary

The side wall seal has frustum-shaped wall (1) made of polyurethane material. A seal dividing section (2) is provided at an external end of the wall. An annular flange (3) is provided in opposite end of the wall. The annular flange is provided with a ring (5) made of polyurethane elastic material. The hardness of the polyurethane material of the ring is greater than the hardness of the polyurethane material of the frustum-shaped wall.