Flexible Laminate Vent Valve for Low-Pressure Gas Release

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Solution Overview

Problem

Existing one-way pressure-release valves in flexible multilayer laminates are unreliable during the packaging life cycle, have insufficient output capacity for products with high off-gassing rates, and suffer from oil floating issues during laminate reeling due to suboptimal design of gas release capacity and liquid chamber configuration.

Innovation Solution

A flexible multilayer laminate with integrated one-way pressure-release valves featuring a cavity with liquid, where a first oriented polymer layer is sealed by an adhesive pattern with adhesive-free regions around perforations, and a second polymer layer forms an inflatable outlet tube that disconnects under pressure, allowing gas communication in one direction with a reduced liquid amount to prevent oil floating.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a one-way pressure-release valve is integrated in the flexible package structure, then overpressure issues can be avoided and gas venting is enabled, but the valve may fail to prevent air ingress under negative pressure differentials or have insufficient output capacity for high off-gassing products

Engineering Contradiction:
Improvevalve reliabilityVSAvoidgas release capacity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The valve is segmented into distinct functional zones: a liquid reservoir separated from the gas flow path, a defined channel with specific geometry, and a membrane structure. This segmentation allows the liquid to provide sealing under negative pressure while the channel geometry ensures adequate gas venting capacity under positive pressure, resolving the contradiction between reliability and productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the valve structure have specialized properties: the liquid reservoir provides sealing function, the channel provides controlled flow, and the membrane provides selective opening/closing. This local differentiation of qualities enables the valve to simultaneously achieve high reliability across varying pressure conditions and sufficient gas release capacity.

Inventive Principle:
Principle #3Local quality

2Reliability

If a liquid film is used in the valve channel to prevent air backflow, then sealing under negative pressure is achieved, but oil floating may occur during laminate reeling due to excessive liquid amount

Engineering Contradiction:
Improvesealing performanceVSAvoidoil floating
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

Instead of using excessive liquid that causes floating, the invention applies partial action by providing just enough liquid in the reservoir to form a sealing meniscus in the channel. This controlled amount of liquid achieves adequate sealing performance under negative pressure while preventing harmful oil floating during manufacturing and handling.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The liquid sealing mechanism replicates the function of a traditional liquid seal but in a controlled, miniaturized form within the valve structure. The liquid in the reservoir creates a meniscus that copies the sealing effect of larger liquid seals without the associated problems of excess liquid movement and floating during reeling.

Inventive Principle:
Principle #26Copying

3Productivity

If the valve is designed with high gas release capacity, then off-gassing products can be packaged immediately without degassing, but the valve opening pressure may be too high for low-pressure applications

Engineering Contradiction:
Improvepackaging speedVSAvoidvalve opening pressure
Core Design Contradiction:
ProductivityVSStress or pressure

Solution Approach 1:

The valve design allows parameter optimization where the channel geometry and liquid properties can be adjusted to achieve the desired opening pressure. By changing parameters such as channel width, length, and liquid viscosity, the valve can be tuned to open at low pressure differentials while still providing high gas release capacity through the optimized channel cross-section.

Inventive Principle:
Principle #35Parameter changes

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 reliable and reproducible low-opening-pressure valves with high output capacity, reducing the need for excessive oil and preventing oil floating during reeling, effectively managing pressure differentials and off-gassing in packaging applications.

Implementation Method 1

the one-way valve that prevents the back flow of air into the package must be able to withstand this internal vacuum without failing to prevent the ingress of oxygen

Methodology Applied
Scientific EffectSurface tension: Surface Tension

Implementation Method 2

having a liquid disposed in between the first and second oriented polymer layers

Methodology Applied
Scientific EffectHydrostatic pressure: Pressure Increase

Implementation Method 3

if overpressure occurs in the package, the adhesive-free centre zone can freely bulge outward, forming a channel

Methodology Applied
Scientific EffectElastic deformation: Deformation

Implementation Method 4

permit gaseous communication in one direction, the gas entering through the at least one perforation, into the cavity comprising liquid travelling through the liquid and exiting through the inflatable tube

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Data Source

PatentEP3717240B1Flexible laminate with improved integrated pressure-release valve
Publication Date: 2023.01.25 AMCOR FLEXIBLES DENMARK
  • EP3717240B1 patent drawingFigure 1
  • EP3717240B1 patent drawingFigure 2
  • EP3717240B1 patent drawingFigure 3

AI summary

The present invention is related to flexible multilayer laminates having an improved integrated, one-way pressure-release valve for use in a sealed container for packing gas-producing products. The pressure-release valve is partly disconnected from the rest of the laminate, forming an inflatable outlet tube with at least one large outlet opening and lifting off from the laminate under increased pressure in the pack.The one- way pressure-release valve allows for pressure-release at low minimum opening pressure in a reliable and reproducible way.