Bosch Rexroth’s Paul Hickman outlines steps that can be taken in packaging automation projects to eliminate or minimise waste
The reduction of waste in food production and packaging directly affects profitability and can enhance a company’s reputation through green credentials and certification. But what steps can be taken in a packaging automation project to eliminate or minimise waste? ‘Waste’ is normally viewed as product waste, but there are other less obvious sources of waste and these are the subject of lean production techniques. This can be, for example, wasted energy, wasted space or wasted time.
All modern machines are driven by electronic control systems like a PLC or motion logic controller. It’s common in automation to hear how fast a PLC is, but in reality that doesn’t help you find why your machine has stopped, or help you identify waste. Easy to use, efficient and open systems are what you need and value in those situations, to allow you to quickly identify problems, and easily monitor and optimise your facility.
Reduce product waste
Flexible production lines are a must for modern food manufacturers. Buying habits are changing, meaning lines must quickly swap pack/batch quantities, and be able to handle variable pack dimensions, with near zero waste on changeover.
Managing these requirements is not easy for an automation system. It must be able to cope with complex gear ratios without losing synchronisation over time, and have simple methods for setting offsets after a new job is loaded without actually moving the machine. Rexroth controls take care of these requirements in the background, without needing anything from the operator, and make it simple for a controls engineer to implement and monitor, potentially reducing waste to zero.
On top of this, manufacturers want production data so they can optimise the plant, and know that the data they are collecting is accurate and not affected by changing environmental conditions. In short, the data must be valid over the working envelope of the production line. Rexroth MS2N motors act as a sensor, enabling the motors’ performance to be consistent over the working range of the machine and environmental conditions, and the torque data they return is valid at all times. No one wants to invest in IoT and AI just to end up proving their servomotors report fluctuating data based on motor temperature or speed. Rexroth’s motor data can be trusted.
Reduce wasted energy
Today’s food packaging machines are increasingly driven electrically rather than pneumatically, which eliminates air leaks and compressed air costs. This directly reduces your energy bill, but your electrical system also needs to be energy efficient. This starts in the design and installation of the power electronics where significant savings are achieved by choosing components with regenerative, energy storage or power optimisation features. For example, Rexroth’s HMV-R power supplies with near unity power factor, or IndraDrives and accessories that can share bus power. Choosing this type of component directly reduces your incoming mains current, which in turn reduces your electricity bill. They also minimise wasted heat by storing and re-using energy, which is particularly useful when driving reciprocal loads.
Monitoring electricity usage will give you the data you need to save even more waste. When and why are you using the most electricity, and are there signs of issues on machines due to increased energy consumption? Bosch offers a comprehensive monitoring and reporting package called Phantom Energy for this. It can tell you how much energy you are using, whether issues are arising with equipment, how much energy you’ve saved and the resultant reduction in CO2 emissions. Instant access to the data is available via tablets or PCs.
Reduce machine footprint
Every Operations Director dreams of fitting more machines into the same factory space, as it directly increases return on the capital cost of the entire plant. To achieve this, it is important that a machine builder considers the overall layout of the packaging machinery. One option is to eliminate electrical cabinets and introduce product schemes that reduce cables and trunking. Rexroth offers the IndraDrive Mi range in this instance, which mounts directly on a machine frame with no need for a cabinet. The drive electronics can even be installed on the motor. In all instances, the drives are simply daisy chained together with a single combined power and communication cable. The single cable needs far less trunking, which minimises space and improves reliability by reducing cabling by up to 90 per cent; this is especially important when drag chains are required.
Reduce wasted time
There is nothing more frustrating than being unable to find the simplest information on an automation system. Whether it’s caused by poor HMI design, having to use multiple software packages in parallel, or data that’s difficult to understand, the end result is downtime or, for a machine builder, late shipment and extra on-site commissioning costs when completing the installation.
Ease of use is a major contributor to waste reduction here; even the best-planned software project can overrun because simple tasks are far harder than they should be, or machines are down because the automation platform is difficult to understand and use. It’s hard to imagine that in 2021 there’s still software out there that needs you to design your own touchscreen keyboard, or displays position and speed in encoder counts by default instead of user-friendly units, or doesn’t offer easy implementation of protocols such as Modbus TCP/IP.
Rexroth has one intuitive software package for its entire automation portfolio. This brings all programming tasks and data into one place, making it easier to manage your project and debug code. On top of that, all of our equipment uses real world units, so knowing where something is positioned or how fast it is moving is simple. The installation also comes with pre-written libraries for common applications and communication protocols, such as MQTT or Modbus TCP/IP, which significantly reduces the time needed for coding.
When you combine this software with a powerful oscilloscope or trace feature that can store data and trigger off faults, it becomes easy to track down the sequences that cause problems, for simple logging and debugging. All of which gets your machine up and running as soon as possible. These same tools are used to optimise performance and identify delays by, for instance, identifying and eliminating oscillations caused by mechanical frequencies in pick-and-place robots.
Staying safe while saving time
The other major area where wasted time can be prevented is in safety related control systems. By implementing drive-based safety that can achieve up to SIL3 or PLe, Rexroth enables machine builders or engineering teams to create safe working solutions that are quickly activated and reset, so throughput can be increased without compromising safety.
For more information about any of the products mentioned here, or to discuss how to minimise waste in your food packaging project, please contact me using firstname.lastname@example.org