Optimize the protection of your packaging with water vapor transmission rate analysis
The water vapor transmission rate (WVTR) is a key parameter for assessing a material's permeability to water molecules in gaseous form. This analysis is essential for the food, pharmaceutical, and cosmetic industries to ensure optimal preservation of packaged products by limiting their exposure to moisture.
Evaluating the rate of water vapor transmission allows for the selection of packaging materials adapted to the requirements for protection against humidity, thus ensuring the stability of sensitive products.
How water vapor transmission rate analysis works
The evaluation of the water vapor transmission rate is based on standardized methods that allow for reproducible and reliable measurements.
- Gravimetric method – A sample of material is placed between a chamber containing water and another exposed to a dry environment. Moisture absorption is measured by the change in mass of the sample over a given period.
- Manometric method – The sample is subjected to a vapor pressure difference between two compartments, and the transmission rate is determined by the pressure variation in the dry compartment.
- Method with humidity sensor – The sample is installed in a test cell where the evolution of the humidity is monitored in real time by a high-precision sensor.
These techniques guarantee measurements adapted to industrial requirements, allowing the barrier performance of materials to be optimized.
Technical characteristics of the water vapor transmission rate analysis
The analysis of the water vapor transmission rate is carried out according to rigorous protocols guaranteeing accurate results. Key features include:
- Units of measurement : g/m²/24h (grams of water vapor transmitted per square meter in 24 hours).
- Reference standards : ASTM F1249, ISO 15106, DIN 53122.
- Measurement ranges : from 0.01 to 1000 g/m²/24h depending on the equipment used.
- Controlled temperature and humidity : simulations at 23°C, 38°C or other specific conditions to reproduce the real environment of the packaging.
- Samples tested : plastic films, papers, cardboards, composites and barrier coatings.
These parameters ensure a precise and reproducible analysis of the barrier performance of the materials tested.
For which matrices?
The water vapor transmission rate is a key indicator for many materials used in the packaging industry. The matrices analyzed include:
Main industrial applications
Léa Géréec
Technical and scientific advisor
