Flexible Container Integrity Test Pressure Gradient

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing methods for integrity testing of flexible containers, such as plastic bags used in bioprocessing, often damage the containers due to excessive negative pressure and fail to accurately detect leaks, leading to unnecessary waste and contamination risks.

Innovation Solution

A method involving a fluid-tight sealable test container with a test fluid and a controlled negative pressure difference between the test container and the interior of the flexible container, using a pressure gradient of up to 100 mbar to detect leaks while minimizing mechanical stress and preventing container collapse, employing a test fluid like helium to quickly assess integrity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a high negative pressure is applied in the test container to detect leaks, then the leak detection sensitivity is improved, but the flexible test container may collapse or be damaged

Engineering Contradiction:
Improveleak detection sensitivityVSAvoidcontainer structural integrity
Core Design Contradiction:
Measurement precisionVSStrength

Solution Approach 1:

The system is divided into two separate pressure zones: the test container (1) containing the flexible container to be tested, and the interior of the flexible container itself. By segmenting the pressure application, a moderate negative pressure is applied to the test container while the flexible container maintains its own pressure environment, preventing collapse while enabling leak detection through pressure differential.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent changes the pressure parameter from a single high negative pressure applied directly to the flexible container, to a controlled pressure differential between two zones. The negative pressure in the test container is kept moderate (not excessively low) to prevent container collapse, while still creating sufficient pressure difference for leak detection when test fluid is introduced.

Inventive Principle:
Principle #35Parameter changes

2Strength

If a moderate negative pressure is applied to prevent container collapse, then the container integrity is maintained, but the leak detection accuracy may be reduced

Engineering Contradiction:
Improvecontainer structural integrityVSAvoidleak detection accuracy
Core Design Contradiction:
StrengthVSMeasurement precision

Solution Approach 1:

The test fluid is introduced into the test container before the integrity test is performed. This preliminary action ensures that when the negative pressure is applied to the test container, the test fluid is already present to migrate through any leaks into the flexible container interior, enabling accurate leak detection even with moderate pressure differential.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The test fluid acts as an intermediary substance that facilitates leak detection. Instead of relying solely on pressure differential, the test fluid serves as a detectable marker that migrates through leaks, allowing accurate detection with moderate pressure conditions that preserve container integrity.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the test container is completely evacuated to high vacuum, then the background leak rate is reduced, but the flexible container may be damaged due to excessive pressure difference

Engineering Contradiction:
Improvebackground leak rateVSAvoidmechanical stress on container
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

Different pressure conditions are applied to different locations: the test container (1) is evacuated to reduce background leak rates and improve measurement reliability, while the flexible container interior is maintained at a higher pressure (through test fluid introduction) to prevent excessive pressure differential and mechanical damage. This local quality differentiation resolves the contradiction between reliability and mechanical stress.

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

This approach reduces container damage, enhances leak detection accuracy, and minimizes waste by ensuring only defective containers are identified as unsuitable for sterile use, thereby reducing financial losses and contamination risks.

Implementation Method 1

a test container pump for creating a negative pressure in the test container

Methodology Applied
Scientific EffectNegative pressure: Vacuum

Implementation Method 2

the negative pressure in the test container is lower than the negative pressure in the interior of the closed test container

Methodology Applied
Scientific EffectPressure gradient: Pressure Gradient

Implementation Method 3

the test fluid is filled into the test container arranged in the test container... the interior of the test container is checked for the presence of test fluid

Methodology Applied
Scientific EffectDiffusion: Diffusion

Data Source

PatentEP3193150B1Method and device for carrying out an integrity test on a flexible test container
Publication Date: 2019.12.25 SARTORIUS STEDIM BIOTECH GMBH
  • EP3193150B1 patent drawingFigure 1
  • EP3193150B1 patent drawingFigure 2
  • EP3193150B1 patent drawingFigure 3

AI summary

In a method for performing an integrity test on a flexible test container (1), the test container (1) is arranged in a fluid-tight sealable test container (5), a negative pressure is provided in the interior of the sealed test container (5), a test fluid is filled into the test container (1) arranged in the test container (5), the test fluid present in the interior of the test container (5) is detected, and a negative pressure is provided before filling the test fluid into the test container (1) arranged in the test container (5), wherein the negative pressure in the test container (1) is lower than the negative pressure in the interior of the sealed test container (5), and wherein the pressure difference between the negative pressure in the test container (1) and the negative pressure in the interior of the sealed test container (5) is greater than 0 mbar and is a maximum of 100 mbar.