Still sealed?
How non-destructive testing can guarantee quality in cosmetic containers
Sebastian Fürst, Shimadzu Europa GmbH
Consumer safety and product quality are of immense significance for manufacturing companies. Both can be intimately linked, as, for example, with containers for cosmetic products: The quality and safety of cosmetics can only be guaranteed if the containers are completely sealed. A test should demonstrate whether the industrial computer tomograph XSeeker 8000 helps to take a look “behind the scenes”. Can CT analysis be used to make valid statements about the quality of the containers – and even the contents themselves?
We’ve all been there
This has probably happened to everyone who has used cosmetic products: As soon as you open the outer packaging, you see that the actual container has not been sealed completely, allowing the expensive contents to leak, even if only a little, or that other damage has occurred during transport. It’s quite frustrating, and not just for you. After all, these days everything can be shared instantly on social media, where it may impact the producer’s reputation too. And doesn’t a leak also mean that something can get into the high-quality product and impair its quality or, in the worst case, that we’re now holding a product that’s harmful to health?
“How can manufacturers ensure that we always receive a safe product?” product specialist Kayo Migita from the Shimadzu Corporation wondered. Her answer: “They have to recognize the containers’ weak points without destroying them – then they can take the specific products out of circulation first, if necessary, and manufacture better products in the future.” Is computed tomography the solution? To answer this question, Migita took a closer look at some containers using the XSeeker 8000.
Computed tomography – not just at the doctor’s office
Many people are probably familiar with computed tomography (CT) in a medical context. The first human CT scan was carried out in 1971. One year later, the first commercial computerized tomography scanner was installed at London’s Atkinson Morley Hospital. CT is the most frequently used imaging procedure in medicine in Germany (almost 6.9 million scans were carried out in 2022). [1] “The industrial use is still relatively unknown, although the advantages of the technology for industry are certainly obvious,” says Migita. “You can take a peek inside the test object without influencing it at all.” How does this work exactly?
Simply put, a computer tomograph consists of the following components:
- X-ray source
- Detector
- Rotary mechanics
- Analyzing computer
The X-ray source emits X-rays that penetrate the test object and hit the detector in attenuated form. The radiation is attenuated differently, depending on the material and layer thickness. The result is a two-dimensional X-ray image, which is used to examine bone fractures, for example. To create three-dimensional images of the test object, a large number of these images from different perspectives are required. Thus, a rotation between the X-Ray source/detector and the object is needed.
While in medical CT scanners the combination of X-ray source and detector rotates around the patient to generate the different cross-sectional images, in an industrial CT the source-detector combination is fixed, and it’s the test object that rotates. By combining the cross-sectional images from the different rotations, a complete three-dimensional model is created in the analyzing computer, which can be examined layer by layer.
The first glimpse
For this reason, Kayo Migita selected three different cosmetics to analyze with the XSeeker 8000. The XSeeker 8000 is a compactly sized industrial CT scanner, characterized by high X-ray radiation. A 160- kV output rate for a system placed on a table is a special feature! Migita was curious to see what insights she would glean.
“Cushion foundation” (make-up with cushion)
The box for the cushion foundation is certainly one of the more complex containers in the field of cosmetics. It consists of an outer lid, an inner cover and a base for holding the sponge. Depending on their function, the individual components are either glued, screwed or clamped, providing plenty of opportunity for a leak to occur. The Japanese product specialist reports: “In the open Xseeker 8000, each sample is lit up so that its shadow indicates its position in relation to the detector. This allowed me to quickly position my sample perfectly. After placing it properly, I was able to scan and obtain a clear image of the container. The individual components have been reproduced in great detail. Using the measuring function, I determined a gap thickness of 0.58 mm between the inner fixtures. I found it equally interesting that the image also gave me information about the moisture distribution within the make-up.” There was considerably less liquid in the center of the make-up than on the outside. Was this intended by the manufacturer?
Liquid lipstick
Secondly, the CT expert tested the liquid lipstick. A crack, break or leak could not be detected in the CT image, but a little trick showed that the device can detect leaks in the event of a problem: “I deliberately put some liquid lipstick on the threaded part of the cap. Now I hoped that the device would show the liquid in a different color due to its higher density compared to the container – and I was right. The liquid I applied appeared as a small white area against a dark background.” And when analyzing the liquid, Migita was also able to identify interesting additional quality features: For example, the image showed that the particles were equally distributed. “This will certainly allow the cosmetics to be applied evenly,” Migita commented with a smile.
Powdered eyeshadow
The last sample that Kayo Migita analyzed was powdered eyeshadow. The packaging seals made a good impression, and the sharp images showed the different consistencies and textures of the products in the packaging. Migita shared: “I could clearly see different particle sizes and also the differences in density based on the gray scale as well as fine cracks in the eyeshadow below the surface that would have stayed hidden during a visual inspection.”
Conclusion: Helping to improve quality
Kayo Migita is very impressed by the possibilities of CT measurement of cosmetics and their containers and is eager to hear what the manufacturers have to say about the results when she forwards them. Not only could we tell if there were any leaks and verify the integrity of the products, but we could also draw conclusions about the quality of the cosmetics, for example about the homogeneity of the particle distribution. Migita’s verdict on this everyday test: “I’m sure that the XSeeker 8000 will improve the quality of the products that reach us users in the end, so that, thanks to them, we are able to start the day in the morning even fitter and fresher.”
