The topic of technical cleanliness in industrial parts cleaning can now largely be mastered with the existing knowledge and expertise and in line with requirements. However, a topic is now emerging that still has a surprising number of blank spots on the map - the technical cleanliness of packaging. After all, it is important to ensure that the component is not re-contaminated during transportation so that it no longer meets the specification when it reaches its destination and there is a risk of defects in the field or returns. Packaging in this context includes small load carriers (SLCs), pallets and lids, as well as trays, i.e. inserts for SLCs that ensure optimized, impact-protected storage of components. The latter are also available as self-supporting trays.
E-mobility as a driver
The changing requirements of e-mobility are proving to be a key driver of development. The difficulties and uncertainties in the industry became increasingly clear and Fraunhofer IPA recognized that there was a need for fundamental work as well as an exchange of experience. In addition to research projects on the subject, the IPA also launched the first specialist conference on technically clean packaging. It took place for the first time on November 29 in Stuttgart and was almost fully booked with almost 90 participants. Ten presentations were on the agenda, including a plenary discussion, which approached the topic from different perspectives and from different suppliers and OEMs.
Basically, the presentations showed that non-metallic particles in particular, i.e. fibers and organic particles, which are often created by abrasion of the components in the trays or KLTs, are becoming an increasing problem. So we are talking about particles that used to play a subordinate role in the boom times of combustion engines. In this context, metallic particles do not generally play such a major role, at least up to a permissible size of 200 µm. In this context, IPA packaging tests have shown that the construction of the trays and the design of the component supports have an enormous influence on particle generation. In particular, large quantities of particles can be generated when sharp-edged metallic components rub against the tray. In the course of electromobility, so-called ESD-KLTs or trays are very often used, i.e. charge carriers that are electrically conductive and can dissipate static charges that could damage electronic components. This poses two serious problems. Firstly, such materials are even less resistant to abrasion. Secondly, although these particles are organic, they are electrically conductive and can therefore easily cause short circuits. In this respect, Dr. Markus Rochwicz called for the use of such ESD-KLTs to be deliberately reduced to a minimum, which is possible by rethinking and separating ESD-prone components from components that can later be discharged before assembly. Another decisive factor was the realization that not only does packaging in accordance with cleanliness specifications play a central role, but that cleanliness-compliant unpacking is generally underestimated and yet extremely important. The question of how films or bags are cut open - in the worst case with a knife, in the best case with ceramic scissors, or whether there are collisions with the load carrier when removing bags or components - has an enormous influence on the particle contamination of the component that is to be fed into production.
Not realistic: packaging must be as clean as the component
It also became clear that the frequently postulated requirement that the load carrier or packaging must be as clean as the component cannot be implemented. This is usually not even possible due to the materials and design of the KLTs, and is also economically unaffordable. Furthermore, tests have shown that these cleanliness requirements are also not expedient, as a large proportion of the particles in the packaging do not migrate to the component. However, in addition to the previous work at Fraunhofer IPA, fundamental work needs to be carried out in order to better calculate this risk. In this context, the systematic development of a guideline for setting limit values for packaging from a well-known OEM was interesting.
All in all, the presentations provided well-founded insights into the current approaches of automotive suppliers and OEMs to the topic. The participants' reactions and contributions to the discussion made it clear that a new chapter is being opened here in the field of technical cleanliness. The video contains impressions of the event, as well as short interviews with some of the speakers on the various aspects of packaging cleanliness and a summary discussion with Dr. Markus Rochowicz on the topic.