Automated handling has been used for several decades in the food and drinks sector, but the flexibility and robustness of modern systems, including robots and conveyors combined with vision systems, are allowing them to enter areas formerly confined to manual operations.
Modern, automated handling systems can now cope with a vast array of sizes and shapes, enabling manufacturers to increase productivity when it comes to end-of-line packing — an important growth area for use of the technology.
For example, the initial automated handling on a cheese packaging line in Lincolnshire proved so successful that two more robots have since been fitted. Robotic specialists from TEC Manufacturing in Melton Mowbray fitted two Mitsubishi Electric RV6SL six-axis robots, vision systems and associate equipment and software, all of which come ready for immediate and rapid installation. The Lincolnshire production line serves many supermarket chains and works a relentless 16 hours a day, six days a week. In December this increases to fever pitch, but is followed by its quietest period of the year.
‘To feed today’s insatiable supermarkets, food processors must be supported by the best manufacturing technology and we have to constantly upgrade their systems, improving efficiency year on year,’ said TEC managing director Tony Jones.
‘We develop very flexible production systems for specialist cheese manufacturers because of the variety of product going through the plant.’
The new Lincolnshire robotic packing line may spend the first hour of the day packing 200x4oz cheese wedges in transit cases, then instantly switch to handling traditional 1-2lb cheese truckles going into individual presentation cases.
‘When we were asked to develop the line, we knew instantly that it would require a robotic solution, but installation had to be phased so that we could maintain continuity of supply to the customers,’ Jones said. ‘It therefore made sense to treat the first stage of the project as a proving stage, measuring the efficiency gains and working out the best way to capitalise on these.
‘The findings included the fact that each robot could release four people from manual work on the packaging line, allowing them to be redeployed elsewhere in the dairy on tasks more rewarding to human intuition and intelligence’.
The RV-S series are the latest generation of 6-DOF (degrees of freedom), articulated arm robots from Mitsubishi Electric. With repeatability of 0.05mm and speeds up to 9500mm/s the RV-12SL is one of the fastest and most precise robots in its class.
On the line TEC installed in Lincolnshire, the cheese reaches the robotic packaging stations via a flat-bed conveyor, which is fed by four wrapping machines. This means that each wedge or truckle can be in any orientation and is positioned randomly on the conveyor.
To cope with this, TEC integrated a Cognex vision system with the robot, the camera being mounted directly over the conveyor upstream of the robot. A photosensor alters the camera to each passing cheese so that its image can be assessed for orientation and position.
This information is passed to the robot in time for it to reach out to the correct position, pick up the cheese and rotate it to the correct orientation for packaging.
In line with the growing trend for automation within the sector, Sewtec Automation of Dewsbury, West Yorkshire, has developed a multipack autofeed system for Fox’s Biscuits of Kirkham, Lancashire, including two ABB IRB 340 FlexPicker robots.
The initiative for the project followed audits of the then manual operation. Fox’s management realised that any improvement over the existing manual multipack stacking methods offered real scope for cutting costs and increasing efficiency. The work was labour intensive and required frequent staff rotation to prevent the risk of RSI-type injuries.
Fox’s engineering project manager, Paul Fisher, was involved in sourcing of a fully automated system to meet a range of demanding parameters. The system needed to be: easy-to-use with a foolproof control system; reliable; capable of automatically balancing the speed of two independent product in-feeds with the existing rate of product out-feed; and able to pay for itself in terms of increased productivity in less than two years.
The system automatically stacks multi-packs of Rocky or Classic biscuits — which are delivered from two, independent multi-pack flow wrapping lines — into two- or three-stack configurations, then feeds them into a bumper pack flow wrapper machine.
Sewtec designed a system comprising: two servo-driven, vertical racetrack collators; two slatband conveyors; a Siemens-based control system; and two ABB IRB 340 FlexPicker robots.
The FlexPicker robots were chosen because they can move and orientate objects with speed and accuracy. The system is capable of 150 cycles per minute, whether objects are on moving belts, placed at random or guided.
Product is delivered to the racetrack collators from high-level conveyors at different rates. The racetracks invert the packs to the desired orientation converting random product arrival to a regimented, collated output.
Each racetrack is driven by two servo motors, which work in conjunction to give a divorced input-to-output capability, with a small buffer capacity; this allows for level monitoring and automatic speed adjustment of the downstream wrapper.
Product leaves the collators on two slatband conveyors, which are mechanically linked and driven by a single, inverter-controlled, AC-geared motor.
Stacked multipacks travelling along the two conveyors are then transferred into the flow wrapper in-feed by the two FlexPicker IRB 340 robots.
Fox’s autofeed system has performed well, carrying out collating and stacking tasks with the supervision of just one operator, compared with the four operators previously needed for manual operation.
‘The system is a well thought out and effective solution, which meets the demands of the application in every way,’ Fisher says. ‘The application could have been met through a non-robotic solution, but ABB FlexPicker robots have excellent application versatility, so can be readily redeployed anywhere in the factory, which certainly adds to flexibility.
‘The control system is also very sound, providing foolproof operation and ease-of-use at base level, with Sewtec carrying out programming, fault diagnosis and other high-level functions.’
New handling systems featuring robots that can manipulate a variety of objects are automating previously labour-intensive packaging lines.