Marked for life

With traceability now mandatory for many products, systems manufacturers are coming up with novel solutions for a wide variety of applications. Colin Carter reports.

With the increasing amount of global legislation on marking, traceability is not only desirable, but also mandatory for many products — especially in the event of failure or accident.

This increase has led to a demand for innovative marking systems catering for a wide range of goods. shape, size, and materials may at first seem to present problems, but for most there seems to be a solution.

A recent innovation from Universal Marking Systems combats the problem of marking smooth and/or painted surfaces, which tend to move around or be difficult to hold in place in jigs — especially if the item to be marked is regularly shaped.

The company has developed a portable vacuum system, which holds the marking head on to the part to be marked by means of an array of suction cups. The system was originally developed to mark painted steel plate, but has since been used on other components such as sheet metal and RSJs.

The device employs the company’s SIC-based electromagnetic dot marking system, which can deal with most non-porous clean surfaces and marks as deep as 0.3mm if required.

Portability is also a key attribute of Laser Lines’ new Ulyxe laser marking system, whose key features are a smaller footprint and low running costs. Smaller, faster and cheaper seem to be the guiding principles of much product development these days and this is no exception. The company claims it is the smallest diode-pumped laser marker system on the market.

Also claiming a ‘smallest’ accolade — this time smallest character size — is Alltec’s Laser Business Unit, which produces a five-watt continuous wave fibre laser marking system for coding very small parts. The system is designed to mark electronic components — and the size of the latest TVs show how small they have become in recent years. The company claims that character heights of below 150 microns are achievable.

Traceability is a very big issue in the food and drinks sector. The high-volume continental brewer Heineken, for example, has installed a scribing laser coder to mark labels attached to its glass bottles.

Supplied by Linx Printing Technologies to Heineken’s Schiltigheim plant in eastern France, the system is based around the 500SL scribing laser which was chosen for the print quality and low cost of ownership. Also, unlike the company’s previous system, it doesn’t require CO2 gas cartridges for operation.

The laser is mounted horizontally, above the labelling machine, with a marking head down at the pallet station where the bottles are coded with a date and production information. The system can mark 50,000 labels/hour and traceability is assured through a computer link with the production management system.

Marking of a different kind is required to produce car radio front panels, where letters and characters are inscribed so drivers can quickly and easily distinguish between the volume and the tuning knobs.

To this end, Rofin-Baasel has developed a system for a European manufacturer in which a computer-controlled laser removes layers of black topcoat from injection-moulded car radio front panels, uniquely marking them. The system is clean and fast, each system being able to mark some 3,500 panels/day.

Text for a new product can be easily generated from a computer keyboard and repeat patterns (comprising elements including fonts, graphics and logos) are stored by the computer. The system comprises a single laser with two marking heads and a galvanometer scanner mirror and lens system which splits the beam to feed the two heads, thus doubling the possible production rate.

An obvious area where traceability is of prime importance is in the medical field. If you are about to undergo surgery you want to know that everything being used in the theatre is clean and safe.

This applies to both the standard sterile surgery kits and to specialised equipment for individual operations such as those required for minimally invasive surgery (MIS) techniques.

UK-based Comis Orthopaedics manufactures implants and equipment for MIS operations such as hip replacement and total hip arthroplasty. These operations require high levels of product integrity in terms of manufacture and cleanliness, and the law requires traceability of every part used.

To achieve this the company chose Pryor Marking’s HP20 Nd:Yag laser marker with V2 enclosure, featuring four-axis control, a 200 x 200mm marking platform and fume control for use with polymer marked plastics to mark all their parts.

Laser marking is one of the final processes undertaken after the parts are machined. Alphanumeric data is applied to mirror-finished polished surfaces or to satin-finish glass beading either on a straight surface or around the edge of a component using a special circumferential marking axis.

All parts are allocated a lot number and can be fully traced in the event of something going wrong.

This represents just a fraction of the many types of marking systems available for a wide variety of applications. A quick scan through any supermarket shelf, for example, will confirm the ubiquity of marking as a function of the need for traceability to conform to the latest legislation.