Slaves to metal might

Consumer industries such as food and pharmaceutical manufacturers have followed the lead of the motor industry, and present one of the main frontiers for robotic applications. Indeed, research completed in 2006 by market analysts Frost and Sullivan suggests that the overwhelming majority of growth in robotics will come from the packaging sector.

“The reason for this,” says Sigpack Systems product manager Roland Czuday, “lies in reducing labour, increasing throughput, harmonising quality standards and retaining flexibility. The amortisation of robot systems can be remarkably short in what are usually high volume production environments.”

Robots find a number of applications in packaging lines - from feed placement to product picking and from materials handling to loading for cartoning and palletising. To date, the most cost-effective robotics solutions have deployed dedicated packaging robots such as 3- and 4-axis top loaders and Delta type pickers. “While there are many applications of SCARA and 6-axis robots, these are usually compromise adaptations of standard robots.”

The reduction in mass of motors, coupled with new modular control platforms has enabled the development of ever faster robots, with tight control loops (fast response times) and easier integration with advanced systems such as machine vision, sensors and other quality assurance equipment. “This is never truer than in the case of Delta robots that have low inertia, breathtaking speeds and great flexibility.”

These robots also lend themselves to being ganged in multiple robot work, sharing applications such as making products selections from continuously moving conveyors. Typical of these types of applications is the packing of chocolate selections into vacuum formed trays. Now there are increasing uses of this type of arrangement for everything from assembling varieties of ready-packed lunch boxes through to pharmaceutical packs containing devices, leaflets and ancillaries.

Since they are top-mounted, Delta robots can be suspended in multiple arrangements, yet take up very little floor space - an important consideration where property constraints are a major factor. They can be optimised to incorporate overlapping work envelopes while their control loops enable clashes to be avoided. This makes them ideally suited to picking from relatively fast moving lines and can even enable fewer robots to be deployed. The greatest efficiencies come from the integration of robotics into the overall packaging system.

“Taking the systems approach will always deliver the best possible solution,” argues Czuday. “This is because the control platform can be consistent, the various modules of the overall system are inherently compatible, there can be a single source for service, training is simplified and the vendor shares responsibility for the efficacy, reliability and return on investment for the end user. In regulated industries, such as some foods and the pharmaceuticals sector, such systems also aid validation and traceability requirements.”

Flexible automation, in the shape of modern Articulate or SCARA type industrial robots, is now beginning to replace fixed Cartesian systems and bespoke mechanisms in the packaging industry thanks to their capacity to be reprogrammed and redeployed for other processing tasks, thereby increasing their flexibility and return on investment, according to Barr & Paatz managing director Stirling Paatz.

Longer slim-line robot arms, internally channelled cables and the human-like kinematic action of the 6-axis robot in particular also facilitate working in narrow and confined spaces. “In packaging, where execution speed is critical, integral robotics is opening up new primary and secondary packaging applications and offering rapid reconfiguration, agility and flexibility.”

Vision systems are also being widely used for high-speed pick “n” place operations and inline inspection of fast-moving conveyors. The convergence of these technologies with modern IT makes it easier to commission and configure the new packaging lines, adapting to continual variation in production requirements.

Increasingly, production lines are being expected to respond rapidly to changes in consumer demand. Integral to their ability to cope with these requirements is the necessity to minimise the time involved to transfer raw material into a finished, packaged product and run multi-product formats on the same line. This requires machines that are capable of performing not only with greater control, but that are able to do this at higher speeds than ever before.

Software modularisation and intelligent networks also enable production lines to be changed at the push of a button. Different packaging formats can also be achieved by plugging in a variety of machine options to cover multi packaging formats of the same production line. Motion control is therefore becoming crucial since it is only through the replacement of mechanical linkages with servo motors that the production line can automatically configure to run multi-product formats.

For many years robotics technology has only been used in highly productive environments involving the use of expensive robot controllers. The revolution in processor power, drive and servo motor performance and miniaturisation has meant that robotic control can now be integrated into standard machine control equipment. This has had an immediate and significant impact by reducing costs and increasing the serviceability of the product.

The food industry has been quick to recognise that kinematics, such as Portal, Delta, Articulated, Gantry and Scara, previously needing specific robot control, can now be realised with standard equipment. As a result, specialised kinematics is being increasingly used to solve an array of product handling issues, and manufacturers are already responding to the development.

Siemens Simotion range, for example, has been developed to include standard function blocks that are designed specifically to control kinematics and produce robotic control. “A high performance multi-axis machine controller is at the centre of the machine architecture and this allows operators to control multiple machine functions from a single central control point,” says Siemens packaging development manager Keith Thornhill.

The two machines usually required to place a product into a carton through a robotic top loader are the carton erector with a smart infeed system and a robotic “pick and place” unit. In the Simotion unit, the robotic element is integral to the system, creating a single fully integrated machine out of the two.

“This is going to revolutionise production lines across a broad range of industries,” says Thornhill. “The single network control will allow faster throughput and greater line flexibility, while the elimination of specialised robotic control will reduce costs significantly.”

New Faces

The Bradman Lake Group integrates ABB pick and place robots into top load cartoning systems and two such cartoners have been developed by Bradman Lake in the US.

The LJ-DRT collator/loader offers dual race track product collation with servo infeed and running speeds up to 600ppm. It has been designed to handle product sizes and cartons up to 700mm long, yet changeovers are said to take less than five minutes.

The LJ-SRT robotic top loader brings automation to the packing of bags of frozen chicken pieces, fish fillets and other prepared foods into cartons. A pick and place loading tool with multiple vacuum heads handles filled bags weighing up to 1kg at speeds up to 350-400/min.

Bagged sizes handled range from 50-200mm long, 20-150mm wide and 6-75mm high. Carton sizes run from 100x100x20mm high to 700x300x165mm high. Custom designed end-of-arm tooling ensures correct pitching.

The LJ-SRT (single race track) is able to handle output from medium speed wrappers, the LJ-DRT (dual race track) is suited to handle the output from medium to high speed wrappers, and the LJ-TRT (triple race track) is able to handle the output from high-speed wrappers.

Meanwhile, ABB Robotics FlexPicker Delta robots, designed for picking and placement, are portal-mounted machines that are reputed to be fast, flexible and to take minimal floor space.

Recognising that some operators remain fearful of the complexity of programming robot lines, the accompanying PickMaster software makes the integration of picking, packing and palletising easy with an intuitive interface. The PC-based software product uses comprehensive graphical interfaces to configure powerful applications where up to 16 robots may work in a team along conveying belts.

TM Robotics (Europe) has launched a ceiling-mounted version of the Toshiba TH450 selective compliant assembly robot arm, which is set to find application in the packaging industry for pick and place tasks.

The TH450 achieves cycle times of less than 0.3 seconds. Arm lengths of 450mm and a payload of 5kg complement the TH450's enhanced speed capability while repeatability is an impressive ±0.01mm. Linear and circular conveyor synchronisation capabilities are also offered, creating a versatile package when combined with easily integrated vision systems.

"Ceiling mount capabilities make the TH450 much more versatile," explained Nigel Smith, managing director of TM Robotics. "The function is already in use in a number of applications but the big advantage of building it into a catalogue product is that it saves engineering time for the end user and the integrator."

The traditional 6-axis industrial robot has undergone a radical redesign with the launch by Motoman of a new model, nicknamed “snake”. Designated IA (individual arm), it has been endowed with an additional degree of freedom to provide even greater positioning flexibility.

At the same time, Motoman has added two sizes of DA (dual-arm) robot based on a similar design. As both arms are mounted on one rotary base, the total number of axes is 13.

All the robots have ± 0.1mm positioning repeatability. The DA types are available with 10kg or 20kg handling capacity, the latter also being the maximum payload for the IA model, which stands 35cm taller at 159cm. Motors and transmissions are built into each axis, with the supply cable running through the arms so there are no trailing leads to restrict freedom of movement in awkward areas.

New from CC Automation, UK and Irish agent for the PAAL Group, is the Elematic 1000VC 6000F, which is a continuous motion top loading system. RSC cases are erected and placed into a continuously moving lug conveyor and the products are picked and placed into the cases using line tracking to provide greater accuracy. Depending on the pack format this machine can run 100 cases/min.

PAAL has designed and built numerous lines for packing mixed packs and multi-variety packs using robotic handling and packaging systems for the food, confectionery and pet food industries. Some of these systems are producing many of the multi pack pet food pouch packs with 4-6 different flavours in one shelf-ready mixed flavour case.

“As product life cycles and packaging styles become shorter this reflects on the capital investment in machinery,” says David Wilson. “When selecting machinery it is important to know whether it can easily adapt to future changes, yet still maintain a commercial advantage.”

Robotics in Action

AA Robotics has significantly reduced handling operations and improved productivity in knife blade dispenser packaging operations at Stanley Tools. The company installed automated packaging technology using Denso robots to maximise the benefits of “lean manufacturing”, reduce stockholding and shortening delivery lead times of blade dispensers for Stanley Tools at Rotherham.The original machine cycle, plus machine loading time, has been reduced by 75%.

Packaging delicate bakery products poses specific challenges for robotics since the goods must be handled with great care and yet at high speeds. Italian packaging company Tecno Pack worked with ABB on a project for a muffin manufacturer. Placed in tray variants of two and four muffins, the customer specified 350items/min. Dedicated robot configurations and gripper technology was required because of the shape and structure of the muffins.

In the order-picking warehouse at Gilde in Tonsberg (Norway), the overriding concern is how to get freshly processed and packaged meat to the customer. About 140 employees currently sort customer orders. For some time now they have had a new colleague, a KUKA KR 180 PA robot. The robot takes care of the goods that are ordered most often and which are consequently dispatched in large numbers.

As an innovator of flexible automation using parallel axis robotics technology, Bradman Lake recently completed two robotic top load packaging lines for Royal Greenland Seafood. Royal Greenland processes fish fillets, portions and fishcakes coated with breadcrumbs, flour or batter as well as bagged products. In each of the two Bradman Lake lines, six pick and place robots, a product locating vision system, triple head carton erector, a high speed carton closer and wraparound case packer are integrated to pack eight product groups into retail cartons and bulk catering packs.

A Motoman SP100X four-axis palletising robot with a Unigripper vacuum suction gripper was chosen to palletise up to 320 cases/hr around the clock at the end of the second production line at Charnwood Foods in Leicester, an RHM Group member that specialises in the manufacture of pizza bases for restaurant chains in the UK and across Europe.

Swiss chocolate manufacturer Chocolat Frey is benefiting from an investment in a high-speed robotic line that copes with over 50 different packaging formats every day. The new Sigpack Systems line, which consists of eight Delta Robots, has reduced manual handling at Chocolat Frey's Buchs factory by placing chocolates into blister packs and blister packs into cartons.