Flexible Seal Liquid Dispensing Module Friction Reduction

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Solution Overview

Problem

Dynamic seals in liquid dispensing devices for viscous liquids like hot melt adhesives suffer from frictional wear, leading to sealing failures and undesired dispensing discontinuities due to increased demands on pressurized air and leakage issues.

Innovation Solution

A liquid dispensing module employing a flexible seal with an upstream and downstream end, where the downstream end is retained by an enlarged portion of the needle and the upstream end by a recess in the dispenser body, ensuring lengthwise compression and minimizing friction, thereby maintaining effective sealing without the drawbacks of dynamic seals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a dynamic seal is used to prevent liquid leakage, then sealing function is improved, but friction and seal wear increase leading to reliability deterioration

Engineering Contradiction:
Improvesealing functionVSAvoidfriction and wear
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent removes the dynamic seal component from the system. Instead of using a dynamic seal between the needle and dispenser body, the invention employs a flexible bellows seal that eliminates the need for a dynamic sealing interface, thereby eliminating friction and wear associated with dynamic seals while maintaining sealing function.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses a flexible bellows seal made of flexible material to provide sealing between the actuator chamber and flow channel. This flexible membrane structure provides effective sealing without requiring sliding contact, thus eliminating friction and wear while maintaining reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If a dynamic seal is used to prevent liquid leakage, then sealing function is improved, but pressurized air requirements increase due to friction

Engineering Contradiction:
Improvesealing functionVSAvoidpressurized air requirements
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

By removing the dynamic seal from the system, the patent eliminates the friction that would otherwise require additional pressurized air to overcome during needle actuation. The flexible bellows seal provides sealing without creating frictional resistance to needle movement.

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of operation

If a flexible bellows seal is used to eliminate friction, then ease of operation is improved, but sealing reliability may deteriorate over time

Engineering Contradiction:
Improveneedle actuationVSAvoidsealing function
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent employs a flexible bellows seal constructed from flexible material that maintains its sealing capability while allowing needle movement. The bellows structure provides both flexibility for movement and sufficient rigidity to maintain sealing integrity over time, resolving the contradiction between ease of operation and sealing reliability.

Inventive Principle:
Principle #30Flexible shells and thin films

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 flexible seal effectively prevents liquid leakage and maintains consistent dispensing by reducing friction and wear, ensuring reliable operation over time with improved sealing efficiency and reduced air pressure requirements.

Implementation Method 1

The flexible seal includes an upstream end sealingly engaging the dispenser body assembly and includes a downstream end. The flexible seal is adapted to seal the flow channel from the actuator

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

The downstream end is adapted to move with the needle. The enlarged portion engaging and retaining the downstream end of the flexible seal to place the flexible seal in lengthwise compression to promote the sealing function

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP2308602B1Liquid dispensing module
Publication Date: 2018.07.04 NORDSON CORP
  • EP2308602B1 patent drawingFigure 1~2
  • EP2308602B1 patent drawingFigure 3
  • EP2308602B1 patent drawingFigure 4~5

AI summary

A liquid dispensing module includes a dispenser body assembly, a flexible seal, a needle, and an actuator. The dispenser body assembly includes a liquid inlet, a discharge outlet, and a flow channel including a valve seat between the inlet and outlet. The flexible seal engages the dispenser body assembly and includes a downstream end. The needle includes an enlarged portion engaging and retaining the downstream end of the flexible seal to place the flexible seal in lengthwise compression between the enlarged portion and the dispenser body assembly. The needle also includes a valve element that moves between open and closed positions. The flexible seal prevents liquid from leaking out of the flow channel.