Product Development: Using Micro-CT to Examine Aseptic Packaging

Aseptic packaging allows food and pharmaceutical products to be stored without refrigeration for six months or more while optimizing food quality and nutrition. This improved stability offers many benefits such as simpler shipping and storage, convenience to the consumer, and reduction in food waste. Specialized processes are used to sterilize the contents and container separately, after which they are combined in a sterile environment to prevent contamination. Today’s consumer demands for safe products and simple ingredients has brought about rising demand, leading to package refinements and sophisticated testing and instrumentation.

In this micro-CT demonstration, we examined an aseptic package with a unique closure system designed to improve customer experiences with the opening process. In this package the integral foil seal is automatically cut and displaced from the channel of the spout during the opening process. This enhanced capability removes the requirement for consumers to remove a secondary cap and then to subsequently open a pull tab. In order to achieve this simplification for consumers, a complex multipar closure system was developed. Micro-CT allows us to non-destructively examine the relationship of the parts to one another in different states of opening.

For this month’s demonstration, we chose to utilize our Bruker SkyScan 1173 system because of its large sample capacity balanced with fine spatial resolution.

Micro-CT Scan of an Aseptic Package

After reconstructing the X-ray attenuation data for the packaging as received in a sealed state and after opening and reclosing the cap, we were able to isolate our view on specific regions of interest, such as the foil seal area under the cap (Figure 1). In this package, the foil seal plays an important role in the multilayer flexible packaging structure to prevent spoilage of the product during storage under ambient conditions. With this importance in mind, we can see the effect of opening the closure based on the images in Figure 1. In the closed state, the foil provides complete coverage across the opening of the spout, preventing the introduction of any bacteria into the package to maintain shelf stability. After opening, the foil seal is completely removed from the spout opening and is tucked away neatly in the package.

Taking a look from a side view, the impact of the mechanics of the closure assembly are clear (Figure 2). In the closed state the foil layer is covering the spout opening and no parts of the cap assembly are visible within the walls of the package. After opening the package, the foil is displaced down into the package with cleanly cut edges. The cutting teeth from the closure are now visible within the package after their travel down and through the foil layer. Interestingly, from this side view we also observe that some product loss occurs through entrapment within the folds of the carton, as shown by the bright signal present in each folded tab.

Taking a look from the top edge of the package orthogonal to the view in Figure 2, we can examine the location of part of the closure assembly as well (Figure 3). In the closed state, we see the cutting teeth ring contained neatly within the closure and the intact foil seal. After opening, the foil seal is removed and as before, we can see the cutting ring positioned further down into the package.

Conclusion

Micro-CT excels as a tool to nondestructively examine packaging and produces a detailed three-dimensional model that can be reoriented in any direction for examination. We hope you found this image of the month interesting. If you have an image of the month sample that you would like us to scan, please contact us by calling Seth Hogg at 610-366-7103 or e-mailing seth.hogg@microphotonics.com

Scan Specifications

All scans completed on our large capacity SkyScan 1173 micro-CT system at the Micro Photonics Imaging Laboratory in Allentown, PA. Reconstructions were completed using NRecon and visualization of 2D and 3D results were completed using DataViewer and CTVox.