Robotics in Packaging Application Developments and Success Factors
Dipl.-Ing. (FH) Frank-Peter Kirgis , MBA
SIG Pack Systems AG , Beringen, Switzerland
(as presented at the Robots 2004 Conference , June 9 and 10, 2004)
(Posted 06/01/2004)
The use of robots in packaging
During the past ten years, the use of robotics in the area of food packaging did increase and new, exciting applications come up very frequently. The standard uses for robots in the food manufacturing environment are in packaging—such as for top loading wrapped articles into cartons, or case-packing, and palletizing, as well as high-speed pick and place applications - and will continue to grow. Robots have become simpler to use, cost less and the technology has evolved to apply to a much wider range of applications today. From decorating machines and extremely reliable Quality Control functions in the process area, to counter mold feeding into wrappers and mold stacking/retrieval systems, robots are showing up everywhere. Developments in special end-of-arm-tooling, vision technology and the controller technology expand the things that robots can do. Not only has robotics become accepted, but given the real world of operating cost pressures, it’s a must that you at least know enough about what’s out there to decide if it makes sense for your needs. If you are not already using some kind of robotics in your factory, you probably ought to be learning all you can about them and looking for opportunities to use them as part of your company’s manufacturing strategy.
Flexibility rules
Up until now coping with wrapping a new product has been a real challenge for the packaging industry. Whereas humans are able to quickly adapt to pack different products, programming machinery to have the same flexibility is another matter. Modifying machinery to package different products was a challenge too far for many until recently. Now, those manufacturers, who have been quick to adopt and install new packaging systems, are stealing an edge over their rivals. This is made possible by specially designed machinery and developments in software. Good packaging companies also provide training to make adoption of new technology straightforward and trouble free. Changeover is especially quick and convenient when the entire packaging process comprises one integrated system.
The deployment of robots in packaging lines is an area where technology is quickening the pace and making human hands redundant. Also, unlike humans, robots do not suffer from repetitive strain, fatigue, boredom or any of the related illnesses or conditions these provoke. Establishing the need for robots in packaging lines, however, requires consideration. First, the investment needs to be cost justified, and then the system must be modeled to make the most of the capabilities of robots.
When it comes to the packaging of products, robots generally fit into three main categories: pick and place applications (where the goods are packed into trays or secondary packages), feed placement (where products are prearranged on a conveyer to ease future packaging) and palletizing (pallet loading and unloading).
Indeed, robots often replace human workers, which is why their acceptance is often a subject of negotiation. However, robots do present a strong case of their own and this is why we are seeing more and more getting to work in food industry.
Incidences of strain industries and lost time in the baking industry are a motivator for many companies to seriously consider the role of the robot. As the USA, UK, and elsewhere in Europe become more litigious, the costs against claims against businesses from workers suffering workplace related injuries will rise.
Consistency is key
The most obvious benefits associated with the installation of robots in a packaging environment are:
- Labor savings
- Reduced sickness
- Overcoming potential and existing labor shortages
- Increase of production through higher efficiency
- Less scrap
- Better product quality
Perhaps less obvious are the savings linked to a reduced head count such as a reduction in cafeteria facilities, staff recruitment and training costs, National Insurance contributions and even the number of parking spaces required.
For the packaging of food items, where speed, consistency or high levels of repetition are concerned, the robot almost always wins over humans in terms of efficiency. But again, when it comes to new products within a packaging line, humans are more adept at coping with more complex tasks. As tasks become more complicated robots have to increase in sophistication. As trends move to greater product and packaging variety, modern robotic systems, like their accompanying machinery, have also had to become more flexible.
In order to get the most out of robots, several factors need to be considered. It is vital to attain:
- Highest line performance
- Highest robot performance
- Highest efficiency (minimum overflow)
- Low robot load (for the highest acceleration and speed)
- High reliability
- High redundancy (i.e. the ability to keep the line running in the event of a robot stopping)
The number of products in flow should equal the required number of robots to fill all the trays. Efficiency is the name of the game and the number of packed products should always be maximized. Improvement in efficiency can be brought about by adjusting the product belt speed to optimise it in line with the robot performance.
Apart from the product feed, line configuration and belt speeds; the positioning of the robot (see Fig. 3) is critical to attain the highest efficiency. A well-defined work area of each robot will stop them encroaching into the picking area of another.
Vision and Tooling are critical factors of success
Robots are equipped with intelligent vision systems. This ensures that wherever products are placed on the belt the robot is able to pick them up, so that wastage is minimal.
The grippers and vacuum tools (see Fig. 4) used by these robots have also been further developed and good packaging companies will offer a selection of these. For example, the airflow vacuum tool is ideal for handling goods with damageable surfaces because it can pick up products without touching them. The Suction Cup is also ideal for handling many kinds of products, especially those with an uneven surface such as biscuits and frozen pizzas. This sucks the product to the vacuum gripper and holds it by using pressure difference, which allows for fast pick up. Finger grippers are best used for products that cannot be handled by suction, such as cakes with loose particles on top. All gripper and suction tools should be easy to clean, quick to be changed over and made from materials suitable for the application.
In conclusion
In summary, once the case for the robot has been analyzed, it is important to address the economics in the process. Measured against human costs, this may be justified, but once line efficiency has been considered, payback may not just come from reduced costs, but also from increased productivity, efficiency and quality. Perhaps the major advantage is the high level of flexibility offered by robotics today. Slight alterations can be made to the robot, so that it is able to cater for a new product in a matter of minutes, without the use of tools.
Technology is helping to create better cakes, pizzas, rolls, candies and all other kinds to food items, which reach the supermarket shelves quicker and consequently leave that shelf quicker. Food manufacturers should not to hold back, but embrace the packaging technology offered today. They will then sit back and reap the benefits.
