Interview about PALL Leica integrated cleanliness analysis solution with Nicol Ecke, Feb. 2017
LMS Heerbrugg, J. DeRose, D. Roccia, C. Raidl
For automotive manufacturers and auto parts suppliers, obtaining component cleanliness results rapidly, accurately, and reproducibly over the entire workflow is a significant advantage. Often for these quality control tasks, multiple instruments from several suppliers are used to perform the analysis. More convenient are one-stop shop solutions from only one source. This is why PALL and Leica Microsystems have joined efforts to come out with a unique, and complete cleanliness analysis solution.
We asked Nicol Ecke, Application Specialist Manager for Applied Microscopy at Leica Microsystems in Wetzlar, Germany, to explain more about how users will benefit from the complete cleanliness analysis solution.
Nicol Ecke: Technical component cleanliness has its origins in the automotive and auto parts supplier industry. The parts and components installed in automobile systems, like fuel injectors, pistons, transmission mechanisms, etc., are becoming smaller and smaller and they have to meet always stricter requirements. The cleanliness of the components has an influence on the quality, functionality, and longevity of these automobile systems. In the worst case, particulate contamination may be the reason for a system failure.
Each supplier must check the cleanliness of its parts and components so that the final product is running smoothly and there are no failures. A thorough cleaning of the parts is essential. Washing machines or cabinets are used for this task. The PALL Corporation is a renowned producer of washing cabinets and filters.
The components are cleaned, the fluid is then filtered, and the particles are collected on the filter surface. The filters are dried in an oven and then can be evaluated in the next step with a Leica analysis system. To characterize their potential to cause damage, the particles are counted, i.e. quantified and classified, with a microscope. Hard particles, such as metals or abrasive residues, have a higher potential for damage. In addition, metallic particles are conductive and can cause short circuits of electronic components. Therefore, having more information about the nature of the particles is important. Reflections from the particles are valuable for indicating whether they are metallic nor not. These so-called "killer particles" (large metal or hard particles), such as abrasive residues, can influence the longevity of a component, the transmission, the diesel injection pump, or even cause a system failure. With a full cleanliness analysis, the "killer particles" should be identified and the source of contamination determined. The aim is to optimize the process chain in order to minimize contamination.
PALL and Leica Microsystems offer together a unique, complete integrated workflow for component cleanliness. PALL offers complete package solutions for equipping cleanliness laboratories: from the extraction, i.e. the separation of particles from the components, to the finished analysis with a suitable Leica optical evaluation system. The customer benefits from the expertise of two renowned companies.
Nicol Ecke: PALL and Leica Microsystems are in the position to perfectly depict the entire workflow for component cleanliness. The customer has the advantage of purchasing an overall solution, rinsing cabinet and particle measuring station, from one supplier without having to give up the advice of PALL and Leica experts. This fact is an added value for customers and offers many advantages, not only for new entrants in the field of component cleanliness, but also in terms of consulting, acquisition, and putting into operation their technical cleanliness laboratory. PALL also offers a comprehensive portfolio of consumables and filters which can actively contribute to process optimization and, for example, minimize the entry of particles.
Nicol Ecke: The acquisition of laboratory equipment from a single party, "get all from one", is a great advantage for the customer. Installation planning and training dates can be agreed upon between PALL and Leica Microsystems. A productive cooperation can be already shown during a product demonstration. The customer already receives a first impression on-site of how such a workflow may look, from component cleaning to analysis.
Nicol Ecke: During the construction or expansion of a technical cleanliness laboratory, the users often would like comprehensive advice. Many questions refer not only to the analysis system, but also the particle extraction. For example, what type of filter material is most appropriate? What influence does the preparation of the filter have on the analysis results? We inform customers about the cooperation between Leica Microsystems and PALL. On request, even a joint demonstration can be performed on-site. PALL has a demo truck (Mini-Lab) equipped with one of its rinsing cabinets and a Leica analysis system. The complete workflow from the cleaning to the analysis of component cleanliness can be demonstrated.
Nicol Ecke: In contrast to gravimetric measurement or manual measurements of the largest particles with a microscope, automated particle analysis with a microscope provides a complete size distribution of all particles, different measurement parameters, such as length and width, as well as objective and reliable measurement results. Choosing the correct analysis system depends on the requirements and specifications of the components. Microscopes are proven to be good analysis systems, because the particles are easy to detect, due to their high contrast from the filter surface, and can be automatically evaluated. A particle’s potential to cause damage can be characterized with the determination of its length, width, and amount. In addition, metal or corundum (sapphire or aluminum oxide) particles, which have a higher potential for damage than, for example, soft plastic particles or fibers, can be distinguished. Particles can be, in accordance with the analysis, re-localized, examined, and documented. They can also be inspected by the optical imaging system using different magnification values and contrast methods.
Leica Microsystems offers a suitable solution for every cleanliness requirement. For the standard analysis according to VDA19 or daily analysis of particles greater than 30 µm, the DMS1000 digital microscope is an ideal solution. Compound microscopes, such as the DM4 M and DM6 M microscope, offer a higher resolution. Here, even particles as small as 5 micrometers, in addition to larger particle sizes, can be evaluated in compliance with standards. This capability is important, for example, when checking the purity of oils or if the components have strict specifications. For these cases, to be able to make evaluation in accordance with standards, higher optical resolutions are needed, as described in ISO16232, VDA19, and DIN 51455.
Compared to particle counting flow meters, which are based on light scattering and provide neither information about the true geometry (length and width) nor the nature of the particles (metallic or non-metallic), microscope based solutions provide detailed and reproducible results. Results and images can be documented in a report at the click of a button. Also, a problem that can occur with flow meters is inaccurate results, for example, oil droplets or air bubbles can be counted as solid particles. Large, heavy particles can fall to the bottom of the liquid and then are often not counted. Therefore, the microscope solution offers decisive advantages, because all the particles can be accurately detected, assessed, analyzed, and documented.
Nicol Ecke: For the automobile industry and its suppliers, review of technical cleanliness has become standard.
Particles can be evaluated simply on the basis of good contrast. With additional information, such as a metallic or non-metallic nature, conductive particles can be identified, which is important for systems like anti-lock brakes (ABS). The big challenge usually for users and analysis systems in practice is when the particle load on the filter is too large. That is to say if many particles form clusters on the filter and, as a result, an evaluation of the filter is not possible. The user is then often finds him or herself in a dilemma. For such a situation, good advice is important, such as reducing the number of components being cleaned or the use of a filter cascade or another filter material. PALL and Leica Microsystems provide this service for their customers.
In addition, the new VDA19 guidelines, which entered into force in 2015, offer the advantage that the emphasis is on the users and they should be given assistance, such as cases when a filter can no longer be evaluated.
Nicol Ecke: For cleanliness analysis in the automotive sector, we are well positioned – standards, application know-how, and good contrast characteristics of the particles. At present, the automotive and auto parts supplier industry still has a ways to go. Other industries are still facing challenges to establish technical cleanliness standards. The requirements for product cleanliness in the fields of medical technology, optics, electronics, and precision engineering are steadily increasing. This increase can be with respect to particulate or film contamination or other artifacts like scratches. For these industries, the organization and definition of technical cleanliness is a challenge: what is to be measured and how? Which contrast method is suitable for specific particles and how can the process then be standardized?
Nicol Ecke: We see two trends. The parts and components are getting smaller and more sensitive. Therefore, the peak has not yet been reached. Additional requirements for component cleanliness are needed. The state-of-the-art does not stand still, it is always improving. There are always smaller and finer components being made and ever narrower tolerances. In addition, more and more information about the particulate impurities are desired to better characterize their potential to cause damage and identify the source of contamination.
Second, the topic of "component cleanliness" is more openly handled and discussed than in the past. There is an intensive exchange between customers and suppliers on the topic.
Leica microscope imaging solutions have been tested by the Fraunhofer Institute for Manufacturing Engineering and Automation (IPA) in Stuttgart, Germany and are found suitable for VDA19. Reliable and reproducible results and easy handling make the Leica analysis systems in practice a trustworthy partner.
Established manufacturers, such as PALL and Leica Microsystems, offer many years of experience in the field of component cleanliness which benefits customers. Both companies have specially trained service technicians and specialists and offer service worldwide. Our over 30 years of experience in the field of technical component cleanliness and the continuous development of new solutions offers many advantages to our customers. Also, we place great emphasis on the proper installation of systems and training of staff. This way of thinking ensures that users who are not experts can operate the system.