Evolutionary changes

Many incremental changes add up to big improvements in Belvac’s beverage can decorator. Nisa Ali finds out about the upgrades

Belvac Production Machinery, the US-based manufacturer of production equipment and turnkey line systems for the canmaking industry, has made a number of improvements to its beverage can decorator that are said to improve efficiency, speed and ease of operation, while reducing energy consumption.

Decorator product specialist Aditya Pelluri explained the changes that have been made to nearly every section of the decorator.

Vertical infeed assembly

The infeed assembly for the cans is now vertical, rather than at a 45-degree angle. This says Pelluri is to avoid gapping between cans. “It’s important to eliminate can gapping during loading onto the star wheel, which helps ensure a smooth load onto the mandrel, reducing machine trips.”

Another benefit of a vertical infeed is that the speed of the decorator can be increased from 1,500 to 2,200 cans per minute improving productivity.

The addition of bolts holding the star wheel in place help to ease changeover times for different can sizes from three hours to less than five minutes, says Pelluri.

The vacuum air drum

Auto-lubricated linear spindle disc

Once the cans are loaded onto the spindle disc, new linear bearings ease the motion of the mandrels. Pelluri says operators would no longer have to manually lubricate the bearings. “We upgraded the spindle disc design to include auto-lubrication. The new design includes four injectors and small lubrication hoses connected to the disc that automatically lubricate these bearings.” This change also increases the life of the bearings, he says.

With linear bearings replacing bushings and pipes that were used on earlier designs of the spindle disc, friction is reduced so less power is needed for the pneumatic air cylinder that pushes the bearings. “So just by changing to this design, it saves a significant amount of power,” Pelluri enthuses.

A further benefit that arises from the lower energy consumption is a substantial reduction in vibration. Pelluri explains: “On the older designs, when running at speeds above 1,400cpm you would have significant toe in and print variations resulting in many images being distorted or misaligned due to the high vibration. That is completely eliminated with the addition of linear bearings in the new design which makes the disc as stable as possible.”

One of the cartridge printing units used on the Belvac decorator

Vacuum air drum

Belvac has introduced dual vacuum loading of cans onto the mandrels. This enables the speed of the printer to be maintained without suffering mis-loadings or can rejections.

Pelluri says that with two vacuum zones, an operator can set different pressure bars. “For customers who are running tall cans, 500ml and above, they would have to reduce the speed of the decorator as mis-loadings would significantly increase, resulting in high levels of spoiled cans. We’ve completely eliminated that now, so speed and volume of production can be maintained,” he explains.

A new transfer disc eases the loading of cans destined for the pin oven

Split spindle disc shaft

The shaft on which the spindle disc rotates has been redesigned to reduce maintenance times. It has been changed and now has two parts: a stub that supports the end vacuum drum frame and the remainder that remains in place. When this stub is worn out, it is easily removable.

“By redesigning the shaft into two pieces, material waste has been significantly reduced helping to make operations more sustainable,” Pelluri says, adding: “You only need to remove the stub portion and replace it, which is cost effective, and that provides a significant reduction in material waste.”

The reduction in downtime is also considerable: “We’ve reduced the associated downtime of changing the assembly from a four-day to a two-hour job.”

Printing sleeves

Belvac also introduced an easily removable printing sleeve that reduces registration downtime and can spoilage. Pelluri says: “On other designs every time you do a label change, you would have to remove each cylinder to change the label plate which causes significant downtime.”

On a decorator, that would be eight cylinders, one for each inker, which each weigh up to 20kg.

“We split the design into a fixed cylinder and an easily removable printing sleeve,” he says, explaining that the sleeve, weighing just 250g, can be popped out using pressurised air. However, he says concerns about registration are allayed as each sleeve has a small cut-out notch that goes on a fixed pin, which is in the same position on every inker cylinder.

Pelluri assures: “You don’t have to worry about registration, as the pin locator allows for registration to always be in the same spot.”

Further time savings in downtime and ease of handling are expected, Pelluri says: “If you have 10 label changes in a day, multiply that by eight cylinders every single time – that’s a lot of weight that the person has to carry.”

Replacing printing sleeves now takes a third of the previous time for label changes: instead of 25 to 45 minutes, it can be completed within seven minutes depending on operator experience, says Pelluri.

Reverse over varnish unit

Customer complaints about the mist of varnish spilling over nearby assemblies when it’s being applied at high speeds have been addressed by a mist extraction unit and guards in the reverse over varnish unit.

Pelluri says mist generated in the areas between the rollers is removed by the extraction unit at two points on the guarding, and excess varnish is also collected in a drip tray at a third point of collection. “This gets circulated back into a day tank, so it’s a closed loop,” he says, keeping the printer “really clean”.

The second improvement made to this section is on the gravure cylinder where Belvac has applied its two-piece design, saving the operator from having to handle a 32kg cylinder every time a change was required. Instead, only a sleeve needs to be removed using pressurised air.

Transfer disc

Belvac also looked at how it could improve the transfer disc, which constantly feeds
the printed cans to the pin oven for curing. Pelluri explains that the older version had bushings and pipes that used up too much energy. The new transfer disc design features rotating bumpers with no linear motion and hence friction.

He says: “The new design facilitates easier loading of the spinning cans onto the bumpers while they rotate. This allows them to be synchronised resulting in fewer dents during the transferring process.”

Can size changes are also easier on the transfer disc, he says. “On the older versions,
you would have to manually take the whole thing up and put it in a different position, which takes a lot of time and a lot of effort.”

Belvac engineered an ACME thread at the bottom of the transfer disc to make it an adjustable transfer. Pelluri says all that is needed to move the disc is a tool, which takes “significantly less effort, with a reduction in downtime”, adding: “During can height changeovers the transfer is easily adjustable with only a tool which reduces downtime.”

Sustainability factor

With many parts in rotation, including the inkers, Belvac is offering an Inkercare Service to inspect, clean and refurbish worn parts.

“All you need to do is send your inkers to us and we have qualified service technicians to rebuild the inker. We completely dismantle the inkers, we check all the parts, and we put new parts back on, rebuild it, and give it to [customers] as new,” Pelluri adds.

The service is open to customers in Brazil and the Netherlands, and is part of the company’s efforts to provide customers with more service offerings “to help increase operational efficiency”.

DIGITAL TRANSITION

Digital direct-to-can printing is becoming increasingly used in certain sectors of the canmaking market, and INX International Ink, a global ink supplier, is keen to help customers make the leap from analogue to digital, using its knowledge of inks and digital applications.

Paul Edwards, vice president of the Digital Division at INX International, says his company’s “products and knowledge” of digital applications would help customers “maximise the profit potential of this technology shift”.

He tells The Canmaker: “Our strategy is to become the number one provider of digital inks and solutions for customers, utilising the vast knowledge of applications with our expertise in digital ink development and the implementation of digital printing systems.”

With PFASNI-free inks currently on the market, serialisation ink in the development and trial stage, and the development of security and low temperature inks, INX are keen to adapt to changing customer requirements. Edwards adds: “We are working on multiple projects to develop innovative digital products for our customers.”

Alex Folloso, who was recently promoted to vice president of R&D Metal Decorating Technology at INX International, says on the traditional print side, the INX 2-pc Metal Color Catalog and INX Digital Color library are invaluable to craft brewers and designers.

“The INX Color Catalog provides actual colour representation on the aluminium substrate. The Color Library allows designers access to the Color Catalog during the label design phase.”

Both see these technologies developing side by side.

“With traditional lithography for metal applications, we expect to see trends toward LED curing technology, or other ways to reduce or eliminate gas use,” says Folloso. “We also anticipate seeing ways to improve productivity such as increasing line speeds, and the development of tools for faster label changes.”

More information:
www.belvac.com
www.inxinternational.com

Previous article
Next article

Recent Articles