Component traceability within manufacturing relies on two fundamental processes: marking and data recording. Traceability within the manufacturing supply chain is essential to limiting the damaging effects of product recalls by allowing the manufacturer to understand, at a basic level, the raw material each component was machined from, the operator of each machining process and which assembly the component forms part of.
Marking, or engraving, is the first step when introducing traceability in manufacturing. Manufacturers use marking technology to apply a permanent, unique identification (ID) mark directly onto a component, such as a 2D Data Matrix Code or serial number and company logo.
Today, two technologies most widely used in direct component marking are Dot Peen and Laser. Dot Peen or Laser technologies can be integrated within an existing production line or delivered as portable or bench mounted solutions. Whether the technologies be simple bench mounted units for low-volume, high variety output or fully automated robotic cells on a high-speed production line, both technologies produce human and machine-readable marks. The characteristics of each technology offer different benefits to manufacturers and choosing which to invest in depends on a variety of factors, often unique to the product or supply chain. Industry specifications often define and control marking methods, such as depth, size or location, and must be adhered to in order to enter the supply chain; all aspects influencing the manufacturers choice of marking technology.
Dot Peen marking machines, first invented in the 1970’s, are a versatile technology for direct part marking. Dot Peen continues to be the preferred marking technology for a wide variety of industries, including the aerospace supply chain. The technology uses an electromagnetically powered solenoid to rapidly drive a carbide or diamond stylus into the surface of a component, creating an inscription from a series of dots. The stylus displaces material during the creation of each dot, rather than removing it, reducing stress on the material being marked; important for manufacturers of critical components such as turbine blades destined for aero engine assembly.
Dot Peen technology is also widely used in metal manufacturing and fabrication industries to mark components before they enter the supply chain. Dot Peen in this industry often uses a pneumatically powered solenoid to drive the stylus deeper into the material, ensuring the unique ID can be read after a coating has been applied or so a mark can be applied through an existing coating. Dot Peen machines are programmable, allowing the user to control the force and speed of the stylus for different materials and marking specifications, as the machine marks along the X and Y axis. To further control the depth of each dot, the sharp tip on a stylus can be ground to different angles ranging from 60 to 120°.
A key difference between Dot Peen and Laser marking is the need for fixturing. Components being marked by Dot Peen require some level of fixturing to ensure a good quality, consistent mark. Laser marking on the other hand, is a contactless marking technology, avoiding the need to clamp the component. This factor can be critical for manufacturers of high value components which clamping or fixturing would damage.
There are different types of laser source available, each ideal for different purposes. Solid state fibre lasers are ideal for industrial marking; low power consumption almost silent, low maintenance (other than maintaining a dust-free lens) and consume no spare parts. Fibre lasers are the most reliable on the market, with the average diode life exceeding 50,000 hours, and when supplied within a light-safe enclosure, incredibly safe to use. Laser marking, like Dot Peen, can be supplied as fully-programmable bench-mounted, portable or production-line integrated systems. Manufacturers can control power, speed and frequency of the laser to achieve different results depending on the material and mark requirements. Increasingly being integrated on modern production lines, laser marking delivers high-speed engraving of a high-contrast ID and the added benefit of flexible line changes without the need to change fixturing, just the selection of a different marking programme.
Both Dot Peen and Laser marking machines are fully programmable to ensure the right mark is applied. Traceability software automatically generates and stores sequential ID’s to avoid duplication or operator error, or a manufacturer can import a series of unique ID’s from a separate manufacturing system. Software forces the operator to scan the unique ID, using a handheld or integrated scanner, at each point during machining, storage or assembly process. Manufacturers can attach a range of data to the unique ID, from images and video logs to factory conditions during each process. The wealth of data collected during the manufacturing process can be used downstream; generation of picking lists or assembly instructions to ensure all components are consumed and assembled correctly.
Marking a unique, permanent ID on every component and scanning it at each stage in the manufacturing and assembly process ensures the ability to instantly recall the full production history at any point during the lifetime of a component, either before it leaves the manufacturing facility or years after joining a product assembly. The software used to apply a mark delivers an even greater range of benefits including process control and manufacturing data collection.