Pneumatic Pressure Testing for Paperboard Containers

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Solution Overview

Problem

Current methods for testing the integrity and leakage of paperboard-based containers are subjective, time-consuming, and unsuitable for automation, often requiring chemicals and being limited in scope, particularly for non-deformable containers like gable top cartons.

Innovation Solution

A method and system involving a pressure testing apparatus with a nozzle and flexible sealing disk to create a gas-tight seal on paperboard-based containers, allowing for the measurement of pressure differences to assess leakage and strength without piercing the container, and a computer program to automate the testing process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the Blue Die Test is used to test container integrity, then leakage detection is achieved, but the method is subjective, time-consuming, and unsuitable for automation

Engineering Contradiction:
Improveleakage detection accuracyVSAvoidtesting speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent replaces the mechanical Blue Die Test with a pneumatic pressure testing system. A pressure source applies controlled pressure to the container interior through a nozzle, and a pressure sensor automatically monitors pressure changes over time. This substitution enables objective, automated leakage detection while significantly increasing testing speed and productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a nozzle as an intermediary component that delivers pressurized gas to the container interior without piercing it. The nozzle, combined with a flexible sealing disk, creates a gas-tight seal that allows pressure application while maintaining container integrity. This intermediary enables automated pressure testing without the limitations of direct mechanical contact or chemical methods.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If the Blue Die Test is used, then leakage can be detected, but unwanted chemicals are required

Engineering Contradiction:
Improveleakage detection capabilityVSAvoidchemical usage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses pneumatic pressure testing instead of chemical-based methods. A pressure source generates controlled pressure applied to the container interior, and leakage is detected by monitoring pressure decay over time. This eliminates the need for unwanted chemicals while maintaining accurate leakage detection capability.

Inventive Principle:
Principle #29Pneumatics and hydraulics

3Reliability

If indirect pressure measurement via second deformable volume is used, then non-destructive testing is achieved, but the method is limited to deformable packages and sensitive to relative movement

Engineering Contradiction:
Improvenon-destructive testing capabilityVSAvoidcontainer type compatibility
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent creates a gas-tight seal on the container exterior using a nozzle and flexible sealing disk before applying pressure. This preliminary sealing action allows direct pressure application to the container interior without piercing, making the method suitable for both deformable and non-deformable containers including gable top cartons. The seal is established in advance, eliminating sensitivity to relative movement during testing.

Inventive Principle:
Principle #10Preliminary action

4Reliability

If container samples are continuously taken for testing, then integrity level is monitored, but production time is lost

Engineering Contradiction:
Improveintegrity monitoringVSAvoidproduction downtime
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces manual sample extraction and Blue Die Test procedures with an automated pneumatic pressure testing system. The system can quickly test containers directly on the production line without removing samples or stopping production, thereby maintaining integrity monitoring while minimizing production time loss.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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

Enables objective, efficient, and automated testing of paperboard-based containers for leakage and strength, suitable for various container types, including gable top cartons, without the need for chemicals, providing accurate and repeatable results.

Implementation Method 1

determining a pressure difference between a maximum pressure value and a minimum pressure value, wherein the pressure difference is a measure of leakage and/or strength of the container

Methodology Applied
Scientific EffectPressure measurement:

Data Source

PatentEP3839470B1Method and apparatus for testing paperboard-based containers
Publication Date: 2025.01.15 ELOPAK AS
  • EP3839470B1 patent drawingFigure 1~3
  • EP3839470B1 patent drawingFigure 4
  • EP3839470B1 patent drawingFigure 5

AI summary

A method of testing leakage and/or strength of paperboard-based containers is disclosed. The method comprises the steps of producing a sealed paperboard-based container (10); producing a through-opening (26) in a panel (18) of the container; and attaching a nozzle (30) to the through-opening. The method also comprises performing at least one of a first series of steps and a second series of steps. The first series of steps comprises: increasing pressure in the container by injecting a gaseous fluid into the container via the nozzle until a predetermined, first pressure value is obtained in the container; closing the nozzle preventing gaseous fluid from entering or exiting the container via the nozzle; after closure of the nozzle, measuring a second pressure value in the container; and using a difference in pressure between the first pressure value and the second pressure value as a measure of leakage of the container. The second series of steps comprises: increasing pressure in the container by injecting a gaseous fluid into the container via the nozzle until the container fails; measuring the maximum pressure value obtained in the container prior to the container failing; and using the maximum pressure value as a measure of the strength of the container. An associated apparatus and system is also disclosed.