Maintaining the highest levels of quality control at all stages of manufacture is essential if defect free products are to be dispatched to customers. Invariably there are multiple operations during the manufacture of a component, presenting a number of different opportunities for mistakes to be made, and subsequent value to be added to a component that may already be incorrect from a previous process.
Of course the final inspection stage will undoubtedly find the majority of components that do not conform to specification, however not only is this too late, but on occasions a small number might slip through and reach the customer. This leads to additional cost relating to return and replacement and also has a damaging effect on the perception of quality and performance overall.
This article by Andy Toms of TLM Laser, UK and Ireland distributor for FOBA Laser, highlights the quality control benefits that can be realised by introducing the combination of laser marking and patented machine vision technology to manufacturing processes.
Laser marking is used widely across many different industry sectors to identify components, or add traceability information through a combination of alphanumeric text, bar codes and 2D matrix codes. This information can be used in a number of ways: at different stages of manufacture and also in the field to validate component authenticity and / or confirm date of manufacture and batch number etc.
The information contained within these marks only has value if the content is actually correct, produced on the right component and in the correct position on the part. There is little point in having valuable information that is inaccessible once the component is integrated with in a larger assembly, such as may be the case on a vehicle.
A reliable solution to these problems comes in the form of FOBA’s Intelligent Mark Positioning (IMP) feature. This innovative and patented solution automatically detects work pieces; checks part geometry and its position before aligning the mark and engraving accordingly, ensuring precision and repeatability. IMP ensures consistent premium-quality marks and therefore delivers a measurable reduction in the number of defective products.
(TLM Laser offers a range of FOBA laser marking systems including options for iMP)
TLM’s Andy Toms explains the full capability of this feature: “Intelligent Mark Positioning is ideally suited for automated volume production, especially in relation to the aerospace, automotive, electronics industries, and of course the medical technology sector. Intelligent Mark Positioning offers optical inspection and verification functions at both the pre and post process stages.
Prior to marking, images of the part are acquired to determine that the part presented to the system is actually the correct variant. This is achieved through the use of shape recognition algorithms. This feature is also extremely useful where a tray of parts may have been presented for processing. If there is one or more parts missing within the tray, the vision system will recognise this and only mark in the positions where parts are present.
This ensures that part serialisation during marking remains sequential and correct. Without IMP the laser would operate over the empty pockets and therefore not only would component serialisation be incorrect, any missing parts would need to be manufactured and then marked correctly to match the gaps in the serialisation sequence.
Post marking, Optical Character Verifications (OCV) checks are performed to determine a number of criteria. These include: determining whether the marks are accurate in relation to position and alignment, confirming that all of the information that should have been marked is actually present on the part, checking the completeness of logo’s etc. and reading, verifying and grading the quality of bar-to ensure quality conformance and contrast between the mark and the background, ensuring that the mark can be reliably read in the field.”
Additional features include the capability to accept serial number data directly from a database, eliminating the potential for error due to operators entering incorrect information. Serialisation is also useful for internal monitoring and traceability of work in progress at all of the different stages of manufacture. Combined, these features deliver significant value for manufacturers by reducing the risk of errors through 100% inspection pre and post marking, with each check taking just a fraction of a second to perform.
(FOBA’s IMP also makes it possible to read, verify and grade the quality of codes)
Intelligent Mark Positioning is just one of a range of innovations available on FOBA Laser Marking Systems which enhance quality and productivity for volume manufactures across multiple sectors. All FOBA products are available within the UK and Ireland from Bromsgrove based TLM Laser, recognised as a leading UK supplier of laser based technologies for marking, engraving, welding, cutting, cladding, cleaning and 3D metal printing.
