WITH the introduction of new robot system technologies, the face of manufacturing is currently undergoing major changes.
Even in facilities requiring complete and continuous washdown, or in situations as technically demanding as freezer rooms in environments down to -30°C, a new generation of robots can be found.
Up to five years ago the high speed picking market had only been for the large established biscuit and chocolate players, with the technology fairly complex, cumbersome and expensive. However, recent developments have seen the small and medium sized manufacturers taking advantage of the latest generation of high speed picking systems. This change in direction has been due to several factors.
Firstly, it is due to the innovative designs that make up a new range of robot manipulators.
This current generation of delta style industrial robots is replacing the previous generation of Selective Compliant Assembly Robot Armstyle (SCARA) robot systems.
These standard delta robot style systems are becoming available from the major mainstream robot suppliers and can be installed by system integrators.
SCARA although today quite advanced, cannot deliver ‘off the shelf’ what the new generation of high speed picking robots can offer.
High Speed Pickers
In the unpacked food market including chocolates, biscuits and frozen foods, robot systems comprising of one to 20 machines are packing products at rates exceeding 100 picks per minute per machine.
In the case of food products the type of product usually is only restricted by the ability to grip the product, which leads on to the second factor influencing high-speed picking.
To retain high speed picking rates vacuum systems are mainly utilized to secure the product in the gripper.
The last few years have seen a vast array of various sized food grade vacuum cups arrive on the market to match the speed that new high-speed pickers can achieve.
As a result, virtually all medium to large biscuit and chocolate makers are moving towards if not already deploying high speed picking systems.
Changing purchase patterns
At the same time we are seeing a broad range of new food products hitting the market to meet the ‘consumer’ demand that has been created by changes to workforce demographics and changing family dynamics.
Frozen foods continue to drop in price and improve in quality and an unprecedented demand is being seen for these products, fuelled by the increase in the percentage of adults including parents returning to the workforce, more people moving into independent accommodation earlier, and the increase in disposable incomes.
These new markets comprising of ‘healthier’ frozen foods such as seafood, chicken and meat meals as well as frozen vegetable lines, are seeing an explosion in growth and are starting to move towards high speed picking lines to remain competitive and reduce work place injuries such as RSI, while operating multiple shifts.
As high speed picking systems continue to evolve, vision cameras within the automation cell locate product position to within a fraction of a millimetre and calculate orientation to guide the robot to the picking position.
These same vision systems are also used as a quality control check to confirm that the product is within acceptable tolerances, such as checking dimensions or ensuring there are no defects as a result of the manufacturing process such as a burnt area on a frozen fish product.
Products that do not pass Quality Assurance (QA) checks simply pass by the picking systems and are directed into a bulk or waste bin.
Typical production lines that currently employ 15 people to manually pack product are able to gain improved efficiencies and meet their production with six to seven high speed picking robots, with one operator maintaining control of the system, loading consumables, etc.
Stringent wash down requirements in production areas are also able to be met, with the current generation of high speed picking robots rated as washdownable.
The effect of introducing automation results in reduced RSI and other injuries for the production personnel, less handling which improves hygiene, improved Quality Assurance as every piece is now checked and consistent packing speeds, all leading to major labour and product saving gains.
Existing production conveyers can often be retained for the new picking systems, providing minimal downtime to install and commission the system.
Small Production Lines
Even small production lines with two to three people packing products are finding that moving to high speed picking automation achieves considerable sub-two year Return on Investment.
While traditionally packing machinery suppliers designed and built their own robot arms out of several linear units, now, more and more are integrating standard ‘off the shelf’ articulated robot systems.
This trend was evident back in 2002 during the International InterPack exhibition in Europe and will be confirmed at InterPack 2005, where robots will play a major part in many exhibitor displays.
The advantage to the customer is that the robots have an extremely high ‘Mean Time Between Failure’, are able to be reprogrammed on site with a minimal of training when new products come on line, and a high availability of spare parts.
The requirements that packaging machinery designers focus on is speed, payload and reach of the robot system.
The trend emerging from the major robot suppliers in 2005 is the supply of purpose built robots with payloads of 40 kg at speeds exceeding 50 cycles per minute specifically tailored to the packaging industry.
Purpose built palletising robots with payload capacities of around 150 kg have been available for almost a decade.
These machines are targeted at the low to medium rate production lines where the robot may pick and place one to six cartons per cycle typically.
In the last few years the payloads and reach of the robots has increased to allow a single robot to service five lines simultaneously.
With the automotive sector demanding larger payload robots the consumer industry is benefiting with these new designs. Robots with payloads exceeding 550 kg are now being used on high rate production lines where previously dedicated systems dominated.
These high payload robots allow entire layers of product to be palletised in each cycle.
Freezer room robots
The most innovative palletising robot development in the last few years is the introduction of robots capable of palletising in temperatures down to - 30°C.
Utilising special materials such as freezer rated cables, plastics, gearboxes and greases, installations of up to eight palletising robots per facility have been installed recently, completely replacing the manual workforce.
The next few years will be an exciting time for the Manufacturing Industry, where robotic automation will continue to be driven by fierce competition both locally and overseas, resulting in real benefits for the consumer.
Machinery Automation and Robotics will be holding open days in April where they will have on display picking, packing and palletising systems using the latest generation robots integrated with Human Machine Interfaces, Vision, PLC and Safety PLC Systems.
* Jeff Fordham is automation engineer for Machinery Automation & Robotics (MAR) based in Silverwater, NSW.