Graham Mackrell looks at how gears for packaging machines keep your goods fresh
Most people probably open tens of packaged goods a day without even realising it.
Opening jars, cereal packets and sandwich boxes are all part of our daily routine, but we don’t tend to notice the packaging until something goes wrong. When milk cartons burst, drinks spill in your bag or crisps go stale when they’re not properly sealed, it can be infuriating.
Machines used in the packaging industry must deliver high performance in often demanding environments.
High speed, accurate and repeatable movements are necessary in environments where temperature, pressure and loads can place a strain on electromechanical components, including packaging gears.
High quality precision components are vital in machines that cartonise, fill, seal, label and palletise products. These automatic machines process and pack large quantities of material quickly and accurately.
Therefore, the positioning, movement and speed of the machine is necessary to maintain safety and high standards in the factory.
Accuracy and repeatability is made possible through the use of components such as high precision gears that are used to control the movement of arms on packaging machines such as palletisers. Harmonic Drive strain wave gears have zero backlash, which means that the robotic arms of the palletisers are accurate enough to consistently pick and place packages with perfect alignment every time.
When choosing gearing for packaging machines, engineers should also consider the return on investment of the parts. Featuring a low part count and the use of aerospace-grade materials, Harmonic Drive gears boast a high mean-time between failure (MTBF) with no drop in accuracy over the lifetime of the gear, ensuring years of worry-free use.
Repeatability is another key challenge in the packaging industry. With factories such as Crayola producing twelve million crayons a day, machines are often faced with unrelenting levels of use.
Manufacturers should look for excellent positioning accuracy and repeatability. Harmonic Drive offers a positioning accuracy of less than one minute of arc and a repeatability of a few arc seconds. This means that despite a heavy repeated workload, the packaging machines will maintain stability and a high quality output.
Hygiene is another key issue in the packaging industry. Last year in the UK, the Food Standards Agency (FSA) issued 45 alerts involving product recalls or withdrawal due to product contamination. It is therefore necessary that packaging gears should be made from material such as stainless steel, which can be wiped down.
Although maintenance engineers can try their best to eliminate food contamination, it is something that inevitably occurs over time. Therefore, it is important to choose a packaging machine with components designed for easy maintenance and minimal contamination.
Another important consideration when choosing a packaging machine is downtime. A report by the Harting Technology Group says that a system shutdown for one hour of maintenance in a packaging factory can cost the business between 5000 and 50,000 euros.
Therefore, it is important to invest in packaging gears that are rugged enough to handle the high levels of vibration that are commonly found in packaging factories. Harmonic Drive gears solve this problem by being engineered with a tilt resistant output bearing, meaning that the gear units maintain performance under heavy loading, ideal for packaging machines that regularly handle heavy items.
Clearly, engineers need to consider many variables when choosing gears for packaging machines. The quality of the components can have a large impact on both the business and the perception of the business by the consumer. So the next time you open a box of cereal, have a think about the high precision engineering that went into it.
Graham Mackrell is managing director of Harmonic Drive UK.