How to Correlate Drop Test Results with Dart Impact Data in Flexible Packaging

How to Correlate Drop Test Results with Dart Impact Data in Flexible Packaging

Carton drop tests and shipping simulations are often seen as the “ultimate reality check” for packaging performance. However, full-scale drop tests can be costly and time-consuming, and the results can be difficult to translate into material specifications. Dart impact testing offers a laboratory-scale method that, when properly correlated, can act as a predictive tool for drop performance.

The first step is to design an experimental program that includes both dart impact tests and controlled drop tests. Choose a small set of representative packaging structures—for example, standard film, downgauged film, and a higher-performance film. For each structure, conduct dart impact tests to determine the M50 under relevant conditions (Method A or B, specific temperatures, and conditioning). At the same time, assemble filled packages and subject them to defined drop test protocols, such as specific heights and orientations.

Once the data set is built, look for patterns connecting M50 values to drop test outcomes. You may find that packages made from films with M50 values above a certain threshold survive a defined number of drops without failure, while those below the threshold show a high failure rate. The correlation may not be perfect—other factors like seal design, product geometry, and secondary packaging also play roles—but often a usable relationship can be identified.

To strengthen the correlation, be consistent in how you define “failure” in both test types. In dart impact testing, failure is usually defined as visible rupture or puncture of the film at the impact area. In drop tests, you should define what constitutes a failure: leakage, visible tears, or loss of vacuum, for example. Using aligned definitions helps ensure that you are comparing similar failure modes.

Once a correlation is established, dart impact testing can be used more extensively, while drop tests can be reserved for critical design changes or periodic verification. For instance, you might state that “films used for Product X must have M50 ≥ 300 g under Method A to pass the carton drop test criteria,” based on the relationship established in your development program. Over time, this approach reduces the need for frequent full-scale drop testing, while maintaining confidence that packaging will perform as required in the distribution chain.