Measurement technology in a class of its own - computed tomography from WENZEL

The 1zu1 Prototypen GmbH & Co KG based in Dornbirn, Austria was founded in 1996 by the managing partners Hannes Hämmerle and Wolfgang Humml.

Today the company has 160 employees, has been part of the internationally active Prototal Group since mid-November and produces prototypes, small series and series parts for customers from all over the world and for every conceivable industry. In manufacturing, 1zu1 uses the most important 3D printing processes such as laser sintering and stereolithography. When developing new components for its customers, 1zu1 likes to push the limits of what is possible in terms of complexity and precision. Here, metrology plays an extremely important role in measuring and checking the finest details and tightest shape and position tolerances.

1zu1 has already been using optical measurement solutions for eleven years and produces several hundred measurement reports per year. "We know the limits of optical metrology very well," explains Managing Director Wolfgang Humml. "Against the background that the components we produce are becoming increasingly complex and smaller, it was clear to us that we wanted to take the next, innovative step in metrology and that the comparisons of the 3D measurement results to the 3D data sets had to become better and more accurate." Several criteria were important in the search for a new measurement solution.

Industrial computed tomography versus optical metrology

The focus was on the accuracy of the measurement result over the entire 3D part and not just for the area that can be captured with the optical metrology . This is where industrial computer tomography has clear advantages. Compared to tactile or optical measuring machines, the computer tomograph (CT) can also measure internal features with high precision in a non-destructive manner. Especially for measuring transparent components as well as parts with high-gloss mirror surfaces, the optical metrology clearly has its limits. Measuring without prior treatment with a laser scanning anti-reflection spray is not possible with such parts. In addition, the required measuring accuracy cannot be achieved with a spray application. Another great advantage of industrial computer tomography is the speed of the scans and evaluation. Thousands of measuring points can be measured within seconds. In addition, the performance of so-called pallet scans (several components in one scan) offers a shortening of the process cycles and an increase in economic efficiency.

After an extensive selection process, 1zu1 chose the exaCT L CT system with150kV from WENZEL Metrology GmbH in Wiesthal. "Decisive for the purchase were ultimately the guaranteed measurement uncertainty of +/- 5 µm, the convincing CT measurement of our five benchmark problem parts and the impressive surface imaging accuracy without software smoothing," Humml elaborates. "We were so impressed with the measurement results that we were happy to order the first machine built with this configuration, and we are happy to have the system up and running at our facility. The scan times of the system are impressively fast, so we were able to do about 120 scans in normal working hours in the first three weeks of operation." The high efficiency of the CT solution enables faster development times, saving time and money for the end customer as well.

In addition, WENZEL's CT solution has the smallest footprint in its class at 150kV and also offers a scanning volume of 400 mm in height and 235 mm in diameter. "The desire for the largest possible measuring volume with a comparatively small machine type was another important requirement criterion," emphasises Humml. In addition to the small footprint and the large scanning volume, the exaCT L offers another major advantage - transport and assembly do not require any breakthroughs of doors or aisles, which ensures fast and smooth installation without additional effort. The exaCT L is also best in class in terms of system weight, at only 2,650kg, which allows for flexibility of set-up locations.

The exaCT L is the latest development in the extensive exaCT series from WENZEL. The system won Frost & Sullivan's 'Global New Product Innovation Award 2020' in late 2020 based on a worldwide market analysis for industrial computed tomography. "The exaCT L has superior X-ray performance combined with a fast detector, allowing it to quickly measure objects and defects," said Mariano Kimbara, senior industry analyst at Frost & Sullivan. "WENZEL has taken an important step into the market with an intuitive user interface that uses intelligent software to automate all measurement parameters, providing robust customer value. "Three independent travel axes provide great flexibility, enabling high speeds and short measurement and inspection times.

From additive manufacturing to machining

Due to its high quality awareness, 1zu1 has to solve numerous measuring and testing tasks for its customers: Dimensional evaluations, compensation of shrinkage and warpage, testing for inclusions and impurities, geometric tests, assembly analyses (Multiscan) and process monitoring (measurement series), the measurement and test reports are always presented in a customer-friendly and comprehensible manner.

In doing so, 1zu1 relies on technologies such as 3D printing, plastic vacuum and injection moulding as well as mechanical manufacturing. A large part of 1zu1's investment flows into additive manufacturing. The company is a world leader in this field and since 2020 has been a pilot customer and development partner for new 3D printing technologies for EOS, one of the world's leading suppliers of equipment for industrial 3D printing.

Industrial computed tomography and additive manufacturing are two comparatively young technologies that can be excellently combined. While "additive manufacturing" allows new structures, the quality assurance of these novel products is carried out by a CT. On the basis of these results, correction data are generated, which can decisively improve both the dimensional accuracy and the mechanical stability of 3D-printed parts. Especially the complex shapes created by 3D printing often pose difficulties for conventional measuring systems. Only CT technology enables non-destructive material analysis and dimensional accuracy testing.

"What we appreciate about WENZEL is the competent advice and the ability to listen in sales and understand our needs and high requirements. Our direct contact, Bernd Fleckenstein, gave us the feeling at every stage of the decision that we were with the right manufacturer," enthuses Wolfgang Humml. For him as managing director, the preliminary acceptance of the system was also convincing, which was accompanied by Dr. Uwe Hilpert, CT product manager at WENZEL, who was able to explain the measurement of each individual pixel on the ultra-fast 7.5 mega pixel detector in a well-founded and competent manner.

"The CT training was also carried out by Dr Hilpert on our premises in Dornbirn. After a week of intensive training and an in-depth introduction to CT technology, our measurement technicians were 'ready to go', but from the first measurement task onwards they were optimally equipped to operate the system. This is how investments are fun and create added value for us and our customers," sums up Managing Director Humml.

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Conclusion

The industrial computer tomograph exaCT L is a universally applicable testing and measuring device for optimising components and production processes. The measuring solution works highly efficiently with significant added value for the customer. Faster development times save time and costs. If an analysis or inspection of internal structures is necessary, this can be carried out without destroying the component. This also leads to significantly faster scan times and less effort. With only one scan, metrological evaluations and analyses can be carried out from the generated data. The reliable measurement results are documented in a customer-friendly and comprehensible manner. - Here's a thought on the subject of safety: even with less complex consumer goods that are sold in large quantities, failures can occur that have equally expensive consequences for the recall and the reputation of the company. Archiving the measurement results allows for re-analysis in the event of a failure to allow for quick correction or to disprove a potential lawsuit.

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