Materials Performance Supplements


Materials Performance is the world's most widely circulated magazine dedicated to corrosion prevention and control. MP provides information about the latest corrosion control technologies and practical applications for every industry and environment.

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• Second layer of VCI paper on top of the metal parts • Second piece of plywood This system was repeated for multiple layers, at which point the entire pallet was wrapped in non-VCI stretch wrap. For comparison, the corrosion-inhibiting efficacy of a 50-µm VCI PE bag was evaluated. This bag would simulate a large over bag, serve as a pallet liner, and separate the metal part and VCI paper from the plywood. Specif- ically, the test system was as follows: • Sheet of plywood • VCI bag (bottom) • VCI paper • Metal part • VCI paper • VCI bag (top, folded over and closed, not heat-sealed or taped) • Sheet of plywood • Non-VCI PE stretch wrap Thi s sy st em w a s c omp ared to th e current c ontro l sy st em , a s pre v iou sly described, with a single gear component in each pack (Figure 1). The second goal of the test was to track differences in temperature and humidity within the control pack vs. the pack with the 50-µm VCI PE over bag. To accomplish thi s goal , temperature/relative humid- ity (RH) sensors were placed inside both packs during testing. Testing was run for 185 h, at which point the gear components were unwrapped, visually inspected, and photographed. Temperature and RH data were also collected from the sensors placed within the respective packs. Real World Analysis— Ocean Shipments The first real world analysis involved a shipment of metal components from Illi- nois, United States to China. The process involved packing machined parts in small boxes. Each box was lined with 50-µm non- VCI PE film, and within this film, parts were wrapped in VCI paper. Boxes were then bulk packed onto a pallet. The entire pallet of boxes would then be enclosed with a non- VCI PE shrink film. This system was com- pared to a second, less labor-intensive sys- tem, whereby the boxes were lined with VCI barrier paper, but no secondary bag. The entire pallet was covered with a non-VCI PE bag. Within each pack, a temperature and humidity sensor was placed in one box (Fig- ure 2). Conditions were logged for the dura- tion of the 51-day shipment process. The second real world analysis involved evaluating temperature and humidity condi- tions experienced by crawler units shipped from Iowa, United States to Brazil. Two tem- perature and humidity sensors were placed on the crawler ; one attached to a modified fuel cap, and a second attached to a hose on the vehicle exterior. The first sensor allowed for measurement of conditions experienced inside a partially filled biodiesel fuel tank, where the end user had been experiencing repeated corrosion problems during over- seas shipment. Two crawlers were sent; one with standard biodiesel fuel, and the second FIGURE 1 Wrapped gear component prior to testing. FIGURE 2 Boxed parts prior to shipment, with sensor in place. FIGURE 3 Temperature and RH data from the control pack. In this pack, temperature reached 50 °C within 16 h. RH reached 75% in 62 h, and eventually reached 98%, where it remained for the final 36 h of testing. 15 CORTEC SUPPLEMENT TO MP MATERIALS PERFORMANCE JUNE 2019

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