Innovators in glass

Glass Times reports on how Bohle’s R&D programme is driving change in the glass processing sector.

Listed as among Germany’s most innovative SME’s by Business Week – no small achievement in a country renowned for manufacturing innovation – Bohle has been at the forefront of innovation in glass processing technologies for almost a century.

“It’s quite amazing to see where it all began isn’t it,” senior vice president of sales Christoph Schmidt said.

As we migrate around the outside of the room that forms the museum exhibit dedicated to Josef Bohle, who founded the company in 1923, he points to a small pocket pen-knife. “That’s where all of this started – with those small knives,” he said. “It’s incredible huh?”

Hanging above it is an early Bohle advert from the same era. “Josef Bohle Glass-cutters,” it reads, “Cheap and good”. If it may lack the subtlety of a Saatchi & Saatchi campaign, it nonetheless makes the point. Silberschnitt and Diamantor are now synonymous with quality in glass cutting world-wide.

The small museum piece adjoins Bohle’s expansive showroom. From cutting fluid and grinding belts to balustrading, sedimentors and UV bonding technologies, it’s all part of an offer dedicated to glass processing.

The use of carbide steel and polycrystalline diamond cutting wheels has been one of the major innovations in manual and automatic glass cutting technology, delivered by Bohle.

Offering a service life several times longer than that of conventional cutting wheels, they may trace a common lineage back to Josef Bohle’s early Taschmesser design but there are few other similarities.

“Cutting wheels remain a very important part of our business,” Christoph said. “We have invested a lot of time in developing their design significantly improve performance.

“You need to have the right wheel for different jobs; it makes a big difference to product quality and efficiency.”

Among the rows of regimented samples is the Cutmaster Gold carbide automatic cutting wheel, developed by Bohle as an ideal solution for the automatic cutting of laminated glass. Offering up to 10 times the life expectancy of a standard cutting wheel, it can deliver a consistent cut of up to 250km.

These are comparatively small efficiencies individually but with forecast growth in laminate specification, they have the potential to add up. “This is what we’re looking to do,” Christoph said. “They may be there but we don’t necessarily see all of our growth coming from really big innovations.

“Smaller innovations, which are focused, and which deliver real benefits and advantages to our customers, are equally important, and that’s a big part of what our R&D team does – that continuous improvement and innovation.”

Crossing the road to Bohle’s R&D facility you pick up on Germany’s industrial history – we walk past some semi-retired cutting wheel manufacturing machines.

“They’re still very good machines,” Bohle technical engineers Frank Windmann said. “They just process things mechanically, not digitally, and require manual input to set them up. But the product quality is still very good.”

Production is now handed to robotic-arms, bringing even greater efficiency. Despite its size, each glass cutting wheel can go through 10-15 manufacturing processes plus testing using technology unique to Bohle.

In all there are 15 people working within Bohle’s R&D team including 12 in machinery, and specialists who work across its production machinery, industrial cutting, fittings and vacuum lifters. The remainder are chemists working on UV bonding and glass processing technologies.

“Demand for product development can come direct from customers or internally through our product managers or manufacturing teams,” Frank said. “Product managers may see a requirement or we may identify an issue or an opportunity in manufacture to do something better, more simply or more effectively to improve quality.”

Bohle technical engineers Lutz Strehlow said: “You have to understand how you’re going to sell something and that it’s going to make a profit for you and your customers.”

Bohle was an early adopter of 3D printing technology and now has four printers. This has revolutionised its development process, using FDM (fused deposition modelling) to print component parts to an accuracy of 0.1mm.

“3D printing has made a huge difference to cost and the time it takes to develop new products,” Lutz said. “We can print machinery component parts to handles. We can for example print a handle for a suction lifter more quickly than we can find one in a catalogue or online. It also allows us to adjust and to refine dimensions in a way that we simply couldn’t do before.”

He points to a suction clamp. “It’s a new rotatable multi-purpose suction clamp,” he said. “People use them for cameras. We also had a big European supermarket use them to fix banners to the glass of one of their stores. Development took three to four weeks of meetings, discussion drawings and CAD designs before we printed the parts and developed the prototype. We can move very quickly to meet customer demand.”

Veribor suction lifters from Bohle have been used worldwide for decades and the Veribor range has been continually refined to improve ergonomics, raise performance and maximise safety. This includes testing by TÜV and the subsequent accreditation, the TÜV GS mark, an independent guarantee of performance.

Its new 601 heavy duty suction lifter cup is a recent evolution of this offer. In production for two decades but recently re-launched by Bohle, it’s approved to 120kg but tested to a double safety factor.

Developed in response to customer demand, it features a new ergonomically designed single moulded aluminium handle and a new cup lip. This provides instant grab on a vertical surface and can be operated with a single hand. The innovation has since been rolled out across Bohle’s Veribor range.

“A new VW Golf will feature lots of new features that an older VW Golf won’t but it’s still a VW Golf,” Lutz said. “People recognise it and they are comfortable with it. That’s one of the things we need to consider as part of the development process. If customers know a product and are comfortable with it, we don’t want to lose that. It still needs to be something that they’re familiar with. We don’t want to make it unrecognisable.”

Bohle also works with specialist partners who support it in calculating potential loadings and performance before final development.

“Do we sometimes get it wrong? Yes sometimes,” Frank said. “But we get it wrong as part of development – not in production.”

Europe-wide changes last year to Reach legislation introduced new controls on the use of the polycyclic aromatic hydrocarbon compounds (PAH). This prompted a change in material which impacted significantly on the load capacity of Bohle’s suction lifter design, prompting range-wide redesign of dimensions to deliver the pre-existing performance with new materials.

“You change a material to another very similar material and you think that it’s going to deliver the same performance but that simply isn’t the case,” Frank said. “It created a huge amount of work to achieve the standard of performance that we had previously achieved across our suction lifter ranges.

“This is what we have to do to stay within the regulations and legislation. It can be frustrating when you see that some other suppliers just ignore these changes.”

He delves into a cupboard and unboxes a competitor product. Opening the seal he said: “See, you can smell PAH – it has a very distinctive odour. It’s illegal but it’s very clear that it’s still being used in a lot of Chinese imports.”

As we walk through the R&D facility Frank pointed to a Bohle sedimentor. “I have just completed a project to improve the efficiency of the sedimentor,” he said. “It’s been my project for the last 12 months. It’s very rewarding to be able to take something through from the start to finish.”

Suitable for elementary to chain-linked, double-sided straight line edgers, Bohle manufactures and supplies three different sedimentors: the 2.4, which has a filling quantity of 2100 litres; the 1.0, (1,000 litres); and the 0.3, which has a filling capacity of 320 litres.

The fully automated system uses a multi-stage process to pump water, first into a settling tank, removing around 70% of heavier glass particles from coolant. Powdered flocculant is added, and mixed using a programme of currents, which then bonds to the remaining glass particles, making them sink.

At the end of the cleaning process, a valve at the floor of the tank opens and the accumulated sludge is flushed into a filter bag by the water pressure. This leaves the cleaned cooling water ready to be returned into the cooling circuit.

This means that sedimentors will support most glass processors in trimming around 10% off the costs of machinery cleaning and associated downtime – paying back against purchase costs in as little as a year.

“It’s a very good system but like everything, it can still be further improved,” Frank said. “This is the Bohle approach. The changes don’t necessarily have to be that big to make a difference to a product and to improve its performance.

“But a lot of what we do is about the continuous refinement of existing products, making sure that they get better and better.”