Eye-catching accuracy

Colorful, shiny or metallic design highlights help cosmetics packaging stand out on crowded store shelves. They also help strengthen a brand's image and build customer loyalty. Known in the packaging world as high-visibility enhancements, these eye-catching elements are typically applied using a process called hot foil stamping.

With nearly 30 years of experience designing and manufacturing hot foil stamping machines, Technoshell maintains its competitive edge through early adoption of the latest technology advancements. Seventeen years of collaboration with B&R have helped the company continually push the boundaries of the traditional hot foil stamping process.

"First impressions are very important in the cosmetics industry," says Technoshell's technical director, Nikhil Baste, "so companies put a lot of effort into how their products are packaged." At the same time, manufacturers are under pressure to make their cosmetics packaging lines more and more efficient. For its new hot foil stamping machine, the TSMglitter-60, Technoshell was therefore looking for a way to boost machine output while solving the accuracy challenges associated with stamping the curved surface of tube packaging.

The process of hot foil stamping transfers colorful, shiny or metallic design elements from a carrier film onto products or packaging using heat and pressure. Even when the decorative foil is being applied to a flat surface, high-quality results rely on precise alignment of the foil, die and products. When the surface of the product is curved, like the tubes used for many cosmetic products, positioning precision becomes even more challenging.

To guarantee accuracy in both the radial dimension (parallel to tube rotation) and the axial dimension (perpendicular to it), Technoshell needed to accurately detect registration in both dimensions. And to achieve the high throughput they were after, that would need to be tightly synchronized with motion control axes at very high speeds.

Together with B&R, Technoshell solved these challenges by creating one of the world's first hot foil stamping machines to offer a machine vision solution that is fully integrated with the machine's PLC and HMI systems. "The tight integration makes it easy to synchronize the machine and camera very effectively," explains Baste.

Along with other parameters, the B&R machine vision system identifies the position of the tube in both the axial and radial dimensions and compares the data against a previously learned image. A matching score is calculated and used to compensate the position of the tube for improved stamping accuracy. The B&R camera's integrated lighting is able to illuminate each tube in the color that maximizes contrast for reliable detection.

B&R's ACOPOS P3 servo drives allow Technoshell to implement the positioning control in only a third of the cabinet space, and a Panel PC 3100 combines PC and HMI in a single device. "We were able to reduce the number of automation components and minimize both footprint and cost," says Baste. "And since all the automation components are connected on a single, high-speed POWERLINK network, the TSMglitter-60 is able to operate in perfect synchronization."

He also notes that Technoshell's engineers were able to implement the machine vision solution right along with the rest of the machine automation in the familiar environment of B&R's Automation Studio. "Having a single tool for all aspects of automation – from engineering and version management to commissioning and diagnostics – is one of the highlights we always enjoy in having B&R as our automation partner."

With the B&R machine vision solution, the new hot foil stamper had no trouble hitting its target speed of 60 tubes per minute and delivering an accuracy of ±0.1 mm axially and ±0.15 mm radially. "The TSMglitter-60 achieves a combination of price and accuracy that is unmatched anywhere in the world," Baste says proudly. "It offers 40% greater stamping accuracy and 20% higher output than its predecessor – thanks to integrated machine vision technology from B&R."

When it comes to solving the industry's demands for improved precision, productivity, availability and easy maintenance, Baste credits the long partnership with B&R that allows them to benefit from the latest advancements in automation. "Thanks to the world-class training that B&R offers, our engineers are able to implement new technologies like machine vision very effectively," Baste notes. "It's always inspiring to be on the leading edge, and we have a lot of very interesting ideas for new projects with the B&R team in the future."