In order to understand film properties, we provide answers to many of the questions that are often asked about film property testing, including:

1. How is this property measured?

2. What is the ASTM test method number?

3. What affects the value of this property?

We also discuss when and why the property is important. Sometimes we compare typical OPP property values with the values for other films. In short, we have tried to design a complete and organized resource about the properties used to characterize flexible packaging films.

The discussion about each property follows the same format.  

• Title states the property name(s).
• Test methods lists the ExxonMobil test procedure number(s) and the related industry standard test method(s). ISO protocol governs the procedure numbering system, and these numbers are long. For simplicity, only the last three digits of the ISO procedure number are stated. For example, the ExxonMobil test procedure number for haze is NAF-OPP-4.10- QCT-3-444, but it is referred to as ExxonMobil #444.
• Definition section contains a brief, but precise, overview of what the measurement is and its units.
• Relevance section discusses the importance of the property. Sometimes this entails describing production methods, applications, or a comparison of OPP film to other film types. Occasionally, this section explains why a property is not relevant.
• What affects... section describes material selection, product design, and process impact the property value. Where appropriate, this section discusses how the property is controlled to target.
• Test principles section provides a thumbnail illustration of the basic test. Key differences between the industry standard test method and the ExxonMobil procedure are distinguished here. The complete ExxonMobil test procedure is available upon request.

NOTE: Illustrations and graphs, in most cases, provide data in US standard units.

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