Valve Closing Member with PTFE Coating for Chemical Resistance

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Solution Overview

Problem

Valves for liquid containers face challenges in maintaining optimal mechanical and chemical performance over time, especially when exposed to corrosive liquids and physical stresses, while also requiring cost-effective and quick fabrication.

Innovation Solution

A valve comprising a conduit made from chemically resistant thermoplastic materials, a movable closing member with a corrosion-resistant coating, and sealing means, fabricated using thermoplastic or thermosetting materials with high mechanical strength and chemical resistance, allowing for easy and quick assembly through heat-sealing processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the closing member is made of materials with high mechanical strength to withstand physical stresses, then the mechanical performance is improved, but the chemical resistance to corrosive liquids deteriorates

Engineering Contradiction:
Improvemechanical strengthVSAvoidchemical resistance
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The closing member is constructed as a composite structure combining a polyamide base material providing mechanical strength with a PTFE coating layer providing chemical resistance. This composite approach allows simultaneous achievement of both mechanical performance and chemical inertness against corrosive liquids.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

Different regions of the closing member have different material properties: the bulk material (polyamide) provides structural strength while the surface coating (PTFE) provides chemical resistance. This local differentiation of material properties optimizes both mechanical and chemical performance in their respective functional zones.

Inventive Principle:
Principle #3Local quality

2Reliability

If conventional valve fabrication methods are used to ensure durability, then the chemical and mechanical performance is improved, but the manufacturing time and cost increase

Engineering Contradiction:
Improvechemical and mechanical performanceVSAvoidfabrication speed
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The PTFE coating is applied as a pre-formed layer on the closing member before final assembly. This preliminary preparation of the chemically resistant surface allows for quicker assembly operations while maintaining the durability benefits of PTFE coating, thereby improving fabrication efficiency without sacrificing performance.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If the closing member is designed to be movable for flow control, then the flow regulation capability is improved, but the exposure to physical stresses and chemical aggressions increases

Engineering Contradiction:
Improveflow control capabilityVSAvoidexposure to stresses and corrosions
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The movable closing member uses a composite structure where polyamide provides the mechanical strength needed for flow control operations while PTFE coating protects the surface from chemical aggressions during movement and contact with liquids, enabling durable flow regulation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The closing member has differentiated material properties: the structural portion provides mechanical integrity for movement and positioning, while the coated surface portion provides chemical resistance during contact with corrosive liquids, optimizing protection where needed.

Inventive Principle:
Principle #3Local quality

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 valve achieves excellent mechanical and chemical performance, withstands physical and chemical stresses, and facilitates quick, cost-effective fabrication, ensuring durability and efficiency in handling corrosive liquids.

Implementation Method 1

fabricated using thermoplastic or thermosetting materials with high mechanical strength and chemical resistance, allowing for easy and quick assembly through heat-sealing processes

Methodology Applied
Scientific EffectHeat-sealing: Heating

Data Source

PatentEP2088354B1Valve for liquid containers
Publication Date: 2013.10.16 GREIF INT HLDG BV
  • EP2088354B1 patent drawingFigure 1
  • EP2088354B1 patent drawingFigure 2

AI summary

The present invention relates to a valve (1) for liquid container, which comprises a conduit (2) for liquid passage having an inlet (3) and an outlet (4), a closing member (5) disposed in the conduit (2), which is movable between an open position and a closed position, and an actuator (6) for driving the closing member (5). The conduit (2) is made of a first chemically resistant thermoplastic material and the closing member (5) is made of a second thermoplastic or thermosetting material. Particularly, the surface (5a) of the closing member (5) that faces the inlet (3) in the closed position, is coated with a third thermoplastic material (5b) which is heat-sealed to said second material and has high chemical resistance