Sustainability in machine tool manufacturing and metalworking industry

With their patented cutting geometry, Franken Cut&Form milling cutters produce polished surfaces with roughness grade numbers from N1 to N3 when performing finishing machining. (Image source: EMUGE-FRANKEN)

According to Gerhard Knienieder, Managing Director at the tool manufacturer Emuge based in Franconia in Bavaria, the “near net shape” trend has emerged in recent years in the machining process. This means that before being machined, the workpieces are adapted to the shape of the finished component to reduce the machining allowance by as much as is possible. The closer the unfinished part is to the finished component, the quicker the job will be completed and there is the additional benefit that less chipping waste will be generated during manufacturing. As a result, there will be less roughing during milling, while finish machining will become more important, for example.

The process of recycling waste has been integrated into the metalworking industry for a long time. Metal chips and other production waste are collected by the manufacturing companies themselves or by specialised recycling companies and fed back into raw metal extraction. According to Knienieder, this primarily concerns precious metals containing cobalt and tungsten, as they are also used by Emuge in tool manufacturing in an important and commonly used process.

Conserving resources with minimum quantity lubrication
Another sustainability trend in the metalworking industry is opting more frequently for minimum quantity lubrication rather than using large quantities of coolants and other lubricants. “In this case, just a touch of oil is required for machining, which, it goes without saying, saves a considerable amount of resources,” Knienieder explains.

He adds that this technique is already being used, primarily in mass production in the automotive industry, and it is now the task of tool manufacturers to prepare an increasing number of tools for this type of use. Knienieder believes that manufacturing has the greatest potential for saving energy. “We need to ensure that less energy is consumed in production, not only to avoid emitting CO2 but also out of self-interest with respect to saving costs,” he says.

He states that digitalisation can help with developing processes that consume as little energy as possible. Nevertheless, he believes that, in the long term, it is essential for companies to review their entire production and supply chains with respect to sustainability. For example, his company will in future also have to approach suppliers to find out about the carbon balance for the crude steel it has purchased.

“In a few years, we will need to be able to prove the carbon footprint for each of our products. This means that it is important for energy consumption to be not only documented but also mapped. Needless to say, this is also crucial for ensuring that we continue to reduce emissions in the long term,” Knienieder states.

High levels of good parts save resources
Given that many options have been exhausted, it is not only because of its greater transparency that many observers view digitalisation of the production process as a major opportunity. It is worth keeping an eye out for innovations when visiting the AMB.

“It is only recently that we have set ourselves up with our ESPRIT CAM system for CNC machines. A key aspect behind this decision was the topic of sustainability,” says Kai Lehmann, Sales and Channel Manager at DP Technology. He continues that, given the increasing shortage of skilled workers, any software for programming a machine tool must first and foremost be easy to operate.

He states that the aim must be for it to be quick and easy to achieve the finished product on the machine. “We have integrated a lot of knowledge into the software to make preparing the machining operating sustainable with respect to programming. It is crucial that we have been able to achieve a high degree of reproducibility,” says Lehmann. He adds that if more machined parts are good parts, because the reproducibility of processes has improved, this has indirect effects on conserving resources.

Flexibility also plays a considerable role. “By using elements of artificial intelligence, we have made progress in terms of operational load. If fewer machines are idle and it doesn't take a long time to adjust to an order, this is also better for the environment,” says Lehmann.

This has been achieved because the software will be quicker to respond to changing situations in the future. For example, a machining job which was originally designed for a Siemens control system can quickly be produced on a Heidenhain system. Equally, a machining task that was scheduled for a milling machine only requires a few steps to be processed on a turning/milling machine.

Automated tool paths
It’s difficult to estimate the impact that solving many challenges in the metalworking industry will have on sustainability. What is clear is that protecting tools and using tool paths which are time- and energy-efficient have an impact on the overall balance and this should be taken seriously.

“Let's take optimising the tool recess. The software now proposes methods which are calculated in such a complicated way that this can no longer be done by people manually programming the control system. For example, among other things, this prevents the tool from being struck or experiencing voltage peaks, and therefore chips are formed evenly at a high machining speed,” says Lehmann.

In addition to improving aspects related to job preparation and individual machines, Lehmann's experience has shown that there is some potential for optimisation when considering all the machinery and its operation.

“When we speak to users, we can see that everyone is at different technological levels. While quite a few have improvements in mind, many aren't able to keep pace with the rapidly changing technology and are keeping an eye on all options,” he says.

Observations on improving the efficiency of entire systems are a good example. Lehmann says that even in the case of brief analyses of machine models, loads, shift operations, set-up times and maintenance times, approaches have been adopted to reduce downtime. “In this case, anything which helps the ROI is also sustainable,” he concludes.

It is clear that, given the challenges posed by climate change, efforts need to be stepped up. From the perspective of a CAD/CAM provider, Lehmann believes that the path is already set out. To leverage the potential with respect to sustainability in the future, the relationship between the software supplier and user must fundamentally change.

“Many small companies are no longer keeping pace with the technological advances. At the same time, we need to engage in increasingly customised and deeper analysis and optimisation for companies. In the future, I see us more as a technology partner than as a supplier. This means that aspects of sustainability can be processed even more effectively once more,” he predicts, naming a trend which crosses the industry.

Source: AMB