How time and temperature affect spiral flow and viscosity

Redefining Epoxy Mold Compound Shelf-Life

How time and temperature affect spiral flow and viscosity, but not shelf-life

When it comes to epoxies and specifically epoxy molding compounds (EMC), end users often mistakenly define the terms “Shelf Life” and “Expiration Date” as the same. The term “Shelf Life” has legal implications (specifically as it concerns suppliers in the automotive supply chain), as a manufacturer’s way of ending any warranty on the material’s final product properties.

We like to argue that epoxy mold compounds never truly expire, and if they can still be processed by the equipment required to transform it, then the final material properties will never be compromised. Two properties that are affected by time and temperatures are Spiral Flow and viscosity, but these are processing parameter properties and not final product properties.
As such, this paper argues that epoxy mold compound manufacturers should introduce the terms “Spiral Flow Behavior” and “Viscosity Behavior” on their products’ technical data sheets. These terms more properly qualify the properties that are affected by time and temperature.

The term “Shelf-Life” should not be defined by the way manufacturers’ currently define it, which is that the material is within a specified spiral flow range. Rather, shelf-life should be redefined by the way their customers use the term – as an expiration date after which the manufacturer ends the warranty of the material’s final product properties. Doing so would both increase the shelf life of the epoxy molding compounds and allow end users to be able to use these products, even it means they must adjust the equipment’s processing parameters.

Please stay tuned for the next part in this series to explore the behaviour of epoxy molding compounds.

Please visit us at to learn more about our whole range of epoxy molding compounds (EMC) including our epoxy mold compound for semiconductors, fiberglass-reinforced epoxy molding compounds, and optically clear epoxy molding compounds (CMC) for optoelectronics. If you have any other questions about how to process and cure epoxy molding compounds please feel free to leave a comment below or don’t hesitate to contact us.

About Chris Perabo

Chris is an energetic and enthusiastic engineer and entrepreneur. He is always interested in taking highly technical subjects and distilling these to their essence so that even the layman can understand. He loves to get into the technical details of an issue and then understand how it can be useful for specific customers and applications. Chris is currently the Director of Business Development at CAPLINQ.

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