For all kinds of plastics, especially for rPET
by Heike Fischer
Sikora AG, known for measuring and control technology, inspection, analysis and sorting systems, presented at the World Recycling Expo in Essen, Germany, the Purity Concept V. This system is based on optical cameras and detects contamination or defects such as black specks or yellow discolourations on transparent and coloured pellets and flakes. PETplanet talked to Mr Felix Wendt, Area Sales Manager.
PETplanet: The Purity Concept Systems are used for the offline inspection, analysis and evaluation of plastic materials in the field of non-destructive testing (NDT). Which technologies are applied?
Wendt: We offer two laboratory systems, which are equipped with different technologies depending on the application. The customer can choose between an optical system, which detects black specks, colour contamination and colour deviations, or an X-ray based system, for metallic impurities in the pellets.
PETplanet: Which measuring principle do you use?
Wendt: The material, which shall be inspected, is placed on a sample tray. The latter is moved automatically into the inspection area, where the material is inspected by the optical respectively X-ray camera. The camera image is then further analysed by our analysis software in order to detect contamination. The whole process takes less than a minute.
PETplanet: What are the output options for the measurement data? How can these be visualised and qualified?
Wendt: Due to the analysis software, included contamination from a size of 50 μm are automatically detected, visualised, and evaluated. A projector is used to colour-mark contaminated material on the sample tray. At the same time, the contamination is highlighted on the camera image. This permits a clear assignment of the contamination at any time. Therefore, one can easily remove the contaminated material for a further analysis in the lab. The software also includes an image gallery of detected contamination as well as many statistics and report functions.
PETplanet: What is special about the Purity Concept V and where is it used for?
Wendt: The Purity Concet V is typically used as a laboratory testing device for quality assurance, e.g. in incoming goods inspection or for material release before delivery to the customer. The system has a colour camera and can be used for many applications. It detects black specks, white spots, colour contamination and discolourations on the surface of flakes, crystalline and amorphous pellets as well as on test plates. What is special about the Purity Concept V, is that it works semi-automatically. Whereas the analysis is fully automatic, the operator can always interact and adjust the settings. E.g., he can zoom in the camera picture and select individual pellets and contamination or adjust the sensitivity of the algorithm according to his needs. The Purity Concept V also provides a test certificate with all information on the quality of the tested material which can be used for material release and delivery.
PETplanet: Sikora reports that this technology is particularly suitable for the analysis of rPET. Have you already received feedback from the recycling industry?
Wendt: The exchange with existing customers is very important to us, as we want to develop further with them. What our recycling customers mainly appreciate about the Purity Concept V is that it is not a black box. The approach of the semi-automated process simply offers many possibilities and allows the operator to get a good feeling about the quality of the product. A good algorithm is of course the basis, but it can never replace the human eye. In addition, the Purity Concept V can analyse not only crystalline but also amorphous rPET pellets. This allows our customers to use the device at different points in the production chain. Besides, test plates, which are nowadays more often used in recycling industry, can be analysed as well. We received feedback from our customers that they are satisfied with the broad wide of applications that our system offers.
PETplanet: Are there requests for further developments of the system?
Wendt: Definitely. We get a lot of inquiries or new ideas for new applications, especially at trade shows. We always have an open ear to the market here, and especially in recycling, we would also like to broaden our base.
PETplanet: Thank you so much for your time and information you shared with us!