Traceability in manufacturing has been commonplace within the aerospace industry for decades. Advances in relatively inexpensive technology with greater networking capabilities are now being exploited throughout the supply chain to ensure reliability and identification of root causes to potential problems. Companies producing even the smallest components are benefitting from increasingly accessible technologies used for marking and tracking components, previously only a feature of manufacturing practices at the very top of the supply chain. Marking and traceability technologies are becoming accessible to wider supply chains as digital technologies allow manufacturers of all sizes and production scales to implement Industry 4.0 solutions within their factories.
The traceability process begins with marking and coding equipment. Effective marking is central to any successful traceability system; if parts cannot be distinguished it is simply not possible to track them. Whilst traditional methods of tagging parts such as with an adhesive label or a human-readable code are widely used and serve their purpose well, they are not truly permanent and come with their faults. A permanent machine readable code or 2D data matrix code, which stores vital data and can be scanned at any point during the life of the part, can quickly and easily be applied directly to a component, by dot peen, scribe or laser marking.
Dot peen is the most common and low-cost method of permanent marking, usually used on metal. It uses a stylus pin that is fired into the marking surface to make an indented dot. By rapidly repeating this and moving the stylus between each dot, writing and images can be applied. Dot peen marking provides fast, accurate, low-stress marking and can mark through coatings or film on the material surface. Dot peen is the preferred marking method by aerospace manufacturers, favouring the low-stress engraving style whereby material is displaced rather than removed, significantly reducing stress to the component being marked. Dot peen marking machines use an electrically driven solenoid to actuate the stylus, but pneumatic actuation can also be used for deep marking or faster marking.
Scribe marking is traditionally the preferred method for automotive VIN marking where a pneumatically-driven pin is driven into the metal surface to be marked. It is then moved through the metal, giving a continuous engraved line to produce the required inscription. Scribe machines are able to produce quality inscriptions with excellent clarity and legibility as part of a very low noise operation.
Laser marking is rapidly becoming the permanent marking method of choice for the growing number of manufacturers introducing traceability within their operations. Laser marking is fast, accurate and high-contrast. This marking method is capable of producing a 2D data matrix code in less than a second, either on a static component or on a fast-moving production line, making it ideally suited to high volume and high variety output. Laser is a non-contact form of marking so avoids creating stress points or deforming the material during the marking process. Non-contact avoids the need to clamp the component being marked, providing the added benefit of safe and easy set up for operators. Once installed, manufacturers using solid state fibre laser marking systems enjoy low running costs. Solid state fibre lasers have become the industry standard for reliable, high quality marking. The laser source is sealed, preventing dust and particle contamination and enables longer distances between the control unit and the marking head, allowing the laser source to be situated remotely from the point of use. Fibre lasers are air-cooled, making them more compact and easier to integrate into existing systems and processes.
Marking equipment can easily be integrated within existing manufacturing environments, whether it be a bench mounted marking machine connected to a PC or a fully networked automated robotic production line laser marking system, manufactures of all sizes can find a solution to fit their needs. Purchasing a touchscreen controller or using an existing PC with traceability software installed allows automated creation and storage of unique identifiers such as serial numbers or 2D data matrix codes. Once marked onto a component, the unique ID can be captured by a machine vision system or handheld reader to accumulate a manufacturing ‘history’ for the part as it passes through different processes and operators.
Traceability offers significant advantages to production engineers tasked with analysing events that may have ultimately led to a product recall. By tracking individual parts and storing a variety of production related parameters, it is possible to identify exactly how, when and where a problem occurred at the earliest opportunity. Speedy identification spots issues before they turn into major problems and could also mean the difference between recalling an entire month’s production and simply changing individual faulty parts.
Designed and manufactured in Sheffield, Pryor’s traceability systems offer a single source supply for permanent part identification, data capture, process control and production monitoring.