PREDICT MOISTURE VAPOR TRANSMISSION RATE OF SEVERAL ARNITEL® GRADES

As an engineer, who designs application parts for a variety of markets, including medical, consumer goods, building and construction, etc., you want to have the ability to predict moisture vapor transmission rates (MVTR) and know how it affects the performance of a material in a specific application. By using Envalior’s MVTR Tool, you can calculate the breathability of several Arnitel® grades. This will enable you to pick the best material for the application.

The MTVR Tool gives you an overview to make easy grade-to-grade comparisons. It quickly calculates MVTR—you can take the output and use the data in your design and developments. Once you compare several grades with one another regarding MVTR and breathability, you can make a decision as to which material grade is best to work with. Plus, you can start planning trials to evaluate our material in your customer’s process.

It is best to use the MVTR Tool during the early stage of a project, so you learn during project development what is the best grade for the application. Application testing will need to be done to assess the breathability in the final part after processing. 

Tool functionality 

The MVTR tool predicts the Moisture Vapor Transmission Rate (MVTR) via thin Arnitel films (more grades to come) in gram per square meter per day [g/m²day].

As a user you will need to input: 

• Grade selection
• Temperature
• Relative humidity outside the cup
• Test type (upright water cup, inverted water cup, desiccant cup)

The Tool output will be MVTR vs Layer Thickness. All the measurements are performed according to common industrial standards based on the cup method like ASTM E96 (upright water cup: E96B and D; inverted water cup: E968W; desiccant cup: E96A, C and E).

For the MVTR one of the three test standards is chosen. With this test type measurements have been performed at various temperatures and humidity conditions. As a measure of the vapor transmission, the weight of the cup is measured over time.

MVTR Model 

The model is based on more than 500 measurements, covering dozens of grades, temperatures between 10 and 40°C, and humidities ranging from 5% to 93%. A hybrid modeling approach is used where knowledge of physical processes are fed to a machine learning model. The median accuracy is 10% for measured values and 22% for measurements not known by the model. In some rare cases, the model might be more off.

We are in the process of expanding the MVTR Tool to more grades, but this depends on the availability of experimental data as well as on the demand for that particular grade. Let us know what grades you're looking for by filling in the feedback form on the bottom right of the page.