DIN 53380-1:2000-07: "Determining the gas transmission rate of plastic film by the volumetric method"

 

DIN 53380-1:2000-07 is a German standard that specifies a volumetric method for determining the gas transmission rate (GTR) of plastic films. This method is essential for evaluating the barrier properties of packaging materials, particularly in applications where gas permeability is a critical factor.

Key Features of DIN 53380-1

1. Volumetric Measurement Method
The standard employs a volumetric technique to measure the amount of gas that permeates through a plastic film over time. This involves monitoring the volume of gas that passes through the film under controlled conditions, providing a direct assessment of its permeability.

2. Applicability
DIN 53380-1 is applicable to plastic films and is designed to assess their permeability to various gases. The method is versatile and can be adapted to test different gases, making it suitable for a wide range of materials and applications.

3. Test Conditions
The standard outlines specific conditions under which the tests should be conducted, including temperature, humidity, and pressure parameters. Adhering to these conditions ensures the accuracy and reproducibility of the results.

4. Result Expression
The gas transmission rate is typically expressed in units such as cm³/(m²·d·bar), indicating the volume of gas that permeates through a square meter of film per day under a specified pressure difference. This standardized expression facilitates comparison between different materials and test results.

5. Complementary Standards
DIN 53380-1 is part of a series of standards addressing gas permeability in plastics. Other parts of the series include DIN 53380-2 which: Focuses on the manometric method for determining gas transmission rates.

• DIN 53380-3: Details the carrier gas method for assessing gas permeability.
• DIN 53380-4: Specifies the infrared absorption method for determining carbon dioxide transmission rates.

These complementary standards provide alternative methods for evaluating gas permeability, allowing for flexibility depending on the specific requirements of the material or application.

 

What is the Volumetric method?

The volumetric method for determining the gas transmission rate (GTR) measures how much gas passes through a sample material (typically a plastic film) over time under controlled conditions. This is a common technique in standards like DIN 53380-1 and is used to evaluate barrier properties of packaging films.

What Is Measured?

• GTR: The amount (volume) of a specific gas (e.g. oxygen, nitrogen, carbon dioxide) that permeates through a known area of material per unit time and pressure difference.

 Basic Principle of the Volumetric Method


Test Setup
The test uses a two-chamber system separated by the test film:
1. High-pressure side (donor side):

• Contains the test gas at a known pressure.
• Gas molecules begin to permeate through the film.

2. Low-pressure side (receiving side):

• Initially evacuated or filled with an inert gas.
• Connected to a volumetric measurement system (e.g., graduated tube, gas burette, or pressure sensor).

Test Procedure

1. Sample Mounting:
   The test film is clamped airtight between the two chambers.
2. Gas Introduction:
   The test gas is introduced into the donor side at a constant pressure.
3. Permeation Begins:
   Gas molecules diffuse through the film and enter the receiving chamber.
4. Measurement:
   The volume of gas that accumulates in the receiving chamber is measured over time using a calibrated volume measuring device.
5. Steady State:
   Once permeation reaches a steady rate, the GTR is calculated based on:
• Volume of gas measured
• Time
• Film thickness and area
• Temperature and pressure

Formula

• VVV = Volume of gas transmitted (cm³)
• AAA = Area of the film (m²)
• ttt = Time (days or seconds)
• Δp\Delta pΔp = Pressure difference across the film (bar)

Units are usually:
cm³/(m²·day·bar)

Advantages of the Volumetric Method

• Direct and simple measurement.
• Useful for many gases.
• Good for comparing barrier properties of different films.

 Limitations

• Less sensitive than other methods (e.g., coulometric or manometric) for very low permeability films.
• Requires precise sealing and calibration.
• Test duration can be long for low-permeability materials.