Six keys to sustainable manufacturing
Unfortunately, when most people hear about sustainability, they think of big ticket items like solar panels or wind farms. But, though they may not have the glamour or get all the attention, it’s the workhorse devices like servo drives, hydraulic pumps, and bearing assemblies that will create the sustainable manufacturing of the future.
Following are six key steps offered by Scott Hibbard, vice president of technology, Bosch Rexroth Corp ., that engineers can follow to make manufacturing more sustainable.
“The first two are pretty obvious, and many of us are doing a good job with these,” says Hibbard. “But the last several are things design engineers need to be thinking about constantly.”
1. Optimize current use of fossil fuels. Cutting energy cost is a win-win situation in today’s environment. Save today by turning machinery off when it is not being used. Replace a single speed motor with a variable speed or servo drive to reduce energy consumption. Use a variable speed hydraulic pump. Also take a look at other alternative sustainable sources of energy—be it wind, solar, or hydroelectric.
2. Eliminate waste. Only consume what you need for the final product. Sounds very simple to us today, but I think we all know that, in the past, our primary objective was to reduce cost or time to market. Nobody knew or cared whether we were using more than we needed. Evaluate if investing in precision manufacturing equipment can be justified by waste reduction.
3. Reduce, or hopefully eliminate, pollution. When you walk around a trade show these days, one of the hot topics is how to reduce environmentally unfriendly substances used in products, as well as byproducts in manufacturing processes. You often hear things about renewed interest in dry, or near-dry, machining, which involves using as little coolant as possible while performing metal removal. Many are also revisiting the de-burring process (removing the burrs from finished material after it’s been cut), another process using quite a few powerful chemicals.
4. Recycle. Look at the amount of metal chips that are made in metal removal processes.a lot easier and less energy intensive to transport. Another solution is to have a chip management facility in-house that melts chips and processes them into small billets that can be transported to foundries for reuse.
5. Recover energy, don’t turn it into heat. Hybrid cars recover energy otherwise wasted during braking, did you know machines can do it too? Power sharing has its roots in machine tools, where the servos used in metal cutting machines and seam machines share power through a single power supply. We can actually take power during deceleration and return it to the main lines. In the past, that energy was wasted, turned into heat, like the brakes on a car.
Another great example is in coordinating the cycles of several metal presses. At first you might think, “Have all the presses go up and down together and then move the material.” But Bosch Rexroth has found that if you skew the cycles slightly, you can use the decelerated, regenerative power in one to help accelerate the other one, according to Hibbard. “That has no effect on the process time, no effect on the cycle time and it doesn’t cost more. But it saves energy. We’ve started to apply our knowledge of shared servo power to other industries like packaging machinery, automation, printing presses,” he says.
6. Save Time. Just saving time, by itself, is indirectly an energy savings. If you can run a cycle faster without using more energy to do it, you can shut it down and save power. Or if it’s a large-scale high-production facility, you can reduce the number of machines you need to produce the same quantity of material.
For more information, visit www.boschrexroth.com .