Direct part marking or DPM is one of the two methods of marking the DoD items with unique identification symbols. It is the technology of applying machine readable 2D data matrix barcodes directly to the surfaces of the parts and items.The marking process is essential for automate the information retrieval process. Basically, the technique enhances permanent unique part identification and improves quality. The Direct part marking process is also useful to reduce errors, reduce the life-cycle cost and improve readiness. Data matrix is the standard for direct part marking.
Direct part marking has the same functionality required for unique identification marking. The DoD function of documentation and databases that are essential for keeping track of the processes such as manufacturing, procurement, shipment, installation and storage are performed with the marking system. The DPM also allows identifying items during storage, handling, functional use, installation, repair, replacement and maintenance.
Application of Direct Part Marking
The DPM is applied to items considering certain conditions such as metal of the parts, thickness of the surfaces, texture of the surface, etc. First of all direct part marking is applied considering the function of the parts for safety critical operation. The shape of the part is important to consider before applying the DPM process of marking. For instance, it is difficult to etch the data elements of the UII on a curved surface. On the other hand, a flat surface makes convenient environment for such marking procedure.
The surface type ad texture of the item influences the direct part marking process. It is difficult to apply different methods of DPM on a polished surface. The environment in which the items are used and the functional life time of the items is essential to consider while directly marking an item. Metal of the item also determines the method of DPM that should be applied to an item. For instance, the chemical etching method can’t be used on all metals as it may affect the functionality of the product.
Although, the marking depth of the direct part marking should not exceed 1/10 of the thickness of the part, it is important to take proper care of the item thickness before selecting the exact direct part marking procedure.
Requirements of Direct Part Marking
The data entered through direct part marking remains readable throughout product life. As durability of marking is the prime aspect of applying item identification, permanent marking of the items can be achieved through this marking method.
As direct part marking considers several aspects, the marking methods ensures that the marking can withstand all environmental conditions that the product will be exposed to under normal operation.
Each marking methods are applied after testing the material of the items and their functional environment. Hence, direct part marking reduces the chance of any harmful effects on the functionality, reliability, or durability of the product.
Benefits of Direct Part Marking
- Reduce program costs
- Eliminate data transposition errors
- Improve data accuracy
- Provide means to verify part configuration and status prior to installation, repair, and overhaul
- Real-time computer system update
- Reduce inventory
- Track the history and quality of parts