Keeping tabs

Laser coding on glass bottles and pharmaceutical bag labelling are just two of the technological responses to laws demanding traceability. Mark Venables reports.


Even before September 11, traceability was an important concern for manu-facturers. Now with increased security and legislation — from the EU’s End-of-Life Vehicles and the Waste Electrical and Electronic Equipment Directives, through to farm-to-fork food traceability requirements — it is even more important.

It is vital that manufacturers are able to track faulty products back to process lines, material batches and even individual workers. Recent product recalls, such as the costly recall in the US of 11 million bottles of paracetamol contaminated with metal fragments, would have been easier if product marking, backed up by a product database, had been in operation. As it was, a total product recall was the only method, although it cost millions of dollars.

There are numerous options for marking components and products, including lasers, inkjet and thermal printing. The choice often depends on quantity, the material to be marked and the aesthetic quality required.

Glass bottle manufacturer O-I has installed laser-coding equipment from Linx at its Harlow facility to enable coding directly on to the bottle while the glass is still hot. The information can be used to identify faulty batches, distinguish between suppliers where customers source bottles from multiple locations and protect against counterfeiting.

‘We were keen to ensure that the container code was easily distinguishable from the information used by the filling company to identify the batch or use-by date of the bottle contents,’ said Mark Eldrett, O-I quality assurance manager. The company also needed a durable solution that could withstand the rigours of being handled through the filling and distribution process. If the text were damaged or removed, said Eldrett, it is useless for traceability or authenticity.

Inkjet coding was considered unsuitable and Linx recommended the use of its hot glass coding laser solution. The principle behind this technology is that better laser coding results are achieved when coding takes place close to the point at which the bottle or jar is formed, while the glass is still red hot. This is because the process generates a clean, smooth mark that is more discreet than codes created on cold glass.

Coding on to glass containers at the point of manufacture presents a number of challenges in terms of the process and the extreme conditions in glass manufacturing plants. For example, during manufacture the temperature of the new bottle reaches 650°C, while the ambient temperature near the production line is about 70°C.

To ensure an effective code, the laser optic is designed to tolerate a long lens-to-product distance and has sufficient depth of focus to deal with the slight inconsistencies in the alignment of the bottles as they travel down the line. The extra-long beam delivery system, comprising flexible arm and printhead, can withstand ambient temperatures up to 70°C. The coder is designed for installation above or beside the production line and has a cooling system allowing it to operate at 45°C.

Automotive component suppliers, even more than the other manufacturers, are under pressure to provide high-quality products at the lowest possible price. Paulstra, a global manufacturer of rubber moulded anti-vibration products, is quality certified and incorporates lean manufacturing techniques with in-process verification systems.

The plants contain dedicated stations for metal preparation, adhesive coating, phosphate, injection transfer and compression moulding and robotic assembly. Because the plant is producing thousands of rubber products each day, the rubber mixing process is one of the most crucial stages on the manufacturing lines. Plant engineers deal with hundreds of rubber mixing batches every day.

Nearly 100 chemicals are used, in powder and pellet form, including curatives and additives such as antioxidants. The challenge was to improve the efficiency of batch inclusion bag labels. One of the areas in which the company wanted to improve its efficiency was in its rubber mixing process. It wanted to reduce waste and increase batch integrity.

‘Any engineer that has ever put a wrong bag of chemicals into a mixer can tell you about the importance of proper labelling,’ said Sebastien Lebon, a Paulstra mixing process engineer.

‘The need to label each batch inclusion bag is just as important, if not more, as ensuring each batch contains the right ingredients.’

For several years, the plants have been pre-weighing the ingredients in low-melt batch inclusion bags. Then the bags are sealed in Lomel bags made from 160 EVA film from US-based J Drasner, to prevent spillage and loss.

‘The bags represented a big improvement over the old method of scooping from a bucket,’ said Lebon. ‘The bagging method has been effective in reducing loss due to spillage and eliminating the need to clean out weighing containers. However, we struggled to find a good method for labelling the bags.

‘The labels completed our automation of this area. Initially, the bags were manually labelled using marker pens. Pens did not work because the ink would often smear and handwriting was not always legible. Also, the handwriting did not look professional.’

Lebon asked the manufacturer of the Lomel bag if it had a solution and it recommended a labelling system developed by Paragon Data Systems — the Lomel Batch Labelling System, which uses labels made from the same material as the bag. The system prints labels on demand with all the relevant information in human readable and barcode form.

At the mixing station, the same system that tells the operator which compounds and the amount that are specified for the particular mix, also verifies the ingredients and provides a record. An Intermec Saber 1552C scanner is used to collect the barcode data and perform ingredient validation.

Plant productivity has improved now the inventory of pre-measured batch inclusion bags is tracked automatically, ensuring the correct bags are available before initiating mixing.

Patheon is a global provider of subcontract pharmaceutical manufacturing that focuses on providing clients with a complete solution. As a manufacturer of pharmaceutical products, it concentrates on quality and total accuracy. It has four sites in Europe, including one in Swindon, and another 10 in the US.

Recently, the Swindon team became concerned that the system they had in place was unable to cope with the ever-expanding database. The old system was based on an operator matching the required label from a selection screen with the intended product code. While it worked well for a while, discrepancies began to occur between the product code and the product description. Patheon turned to GSM for a new system, which continues to use the Labelview printing and design software that was a key feature of the previous set-up. However, the process through which it is now used is far more accurate and simpler.

Operators are now required to fill in a form detailing the information on screen. This data is then sent to a central server and once the relevant data has been found for that label it is sent back to the appropriate terminal where it can be printed off.

The system prevents errors such as products being labelled incorrectly, or out-of-date products being labelled.

‘The accurate production of labels is essential to the functionality of our business,’ said Simon Cove, Patheon production engineer.

‘Every container and package has some kind of label on it and this system of labelling is crucial within the pharmaceutical environment.’