There are different IUID marking methodology for the DoD items and the methods varies depending on the type of item.The Department of Defense has defined vendors’ instructions and requirements for IUID marking and submission of IUID data to the UID Registry. IUID marking includes an encoded data string applied to the item as 2D Data Matrix Symbol. MIL-STD-130 is the governing document with the instructions for the application of 2D Data Matrix and regarded as DoD Standard Practice for IUID marking of US Military property.
IUID Marking Options
As the IUID marking is affixed to or etched on an item to identify it throughout its functional life time, it is essential to give prime consideration to the marking methodologies. The MIL-STD-130 has allowed two types of IUID marking methods for the DoD items- indirect part marking and direct part marking.
Indirect Part Marking:
With indirect part marking, a tag, label or nameplate is attached to the item that contains the IUID data as 2D Data Matrix symbol. There are also two options for indirect part marking:
It is the best option for the DoD contractors to satisfy their marketing needs for the DoD items where a permanent adhesive label can be affixed. The method uses two technologies – thermal transfer on demand printers and direct thermal- for critical barcode labeling applications such as aerospace, manufacturing, logistics and other industries. The thermal-transfer printers work with wide range of durable media and best for outstanding printing quality. Direct thermal printer applies heat directly to the chemically treated media. The advantage of the method is that it is a cost effective method for in-house IUID marking option and simplifies the work of the operators to load media. However, the down side is that the thermal transfer-printers are inadequate with their capabilities of label media.
The data plates for IUID marking are either created in-house or ordered from the suppliers. In case the data plates are supplied by the DoD contractors, the suppliers have to ensure that the plates contain correct IUID data and are affixed to the correct items. Generally, data plates are made up of metals that allow them to resist adverse environmental conditions and chemicals. The advantage of data plates over adhesive label is that they can be attached to the items screws, rivets and other fasteners where the adhesive doesn’t work. The disadvantage of data plates is they require expensive equipments for manufacturing. Again, it requires expense to marking process, fasteners and skilled labours for affixing the plates.
Direct Part Marking:
Direct part marking is the process of directly etching the IUID data to the items that require IUID marking. Ink jet printing, chemical etching, dot peening, laser bonding, and laser etching are the main techniques of direct part marking. However, while applying this marking technology the structural tolerances and composition of the items are taken into consideration. The process of direct part marking (DPM) is preferred for its durability and space efficiency. As the symbols are not read optically, they can perform despite of being covered by dirt or paint. But this IUID marking technology has a serious disadvantage. In case the symbol is not applied correctly, the item is wasted.
While applying the IUID marking, the contractors need to decide the marking methodology for the items.