Vision for food manufacturing

In this article Professor John O’Gray applies his expert knowledge of robotics and automation to the food manufacturing industry and gives a fresh perspective of potential future development.

The manufacture and supply of food products comprises one of the largest sectors in the UK economy and is a major employer of labour and a significant user of energy and logistics. It has a national customer base as everybody, at some time, must buy its products and it has a major responsibility to deliver a very wide range of high quality and safe food products at affordable prices to numerous sales outlets.

The food sector is characterised by a requirement to manufacture and transport products whilst maintaining high standards of hygiene. The industry must also react quickly to a rapidly changing market for both product quantity and variety. The volatility of this market has fostered a ‘just in time’ philosophy for manufacturing and also a highly organised logistics infrastructure – thus, success requires managerial skills of a very high order.

This article explores some of these manufacturing procedures and the possibility of using modern automation techniques to increase efficiency of manufacture and improve the consistency of output quality.

Given the sheer diversity of the industry, a selection of issues are presented that are regarded as important factors influencing automation utilisation in the sector. The current state of relevant technology is reviewed and an outline of some innovative developments is given.

The current scene

Following studies of production lines for assembled food products it is clear that, while there are some excellent examples of automation procedures that are successfully exploited, the process is generally labour intensive. There is often reliance on a relatively small core of staff supplemented by contract labour to meet fluctuating demand. There are issues related to the recruitment, retention and training of staff. Working conditions are often not ideal due to the requirements of low processing temperatures; the necessity to constantly wash lines and superstructure to ensure hygienic operation. With a large manual workforce, product traceability and product consistency pose significant management problems. Manufacturers generally pay great attention to the well being and safety of their staff and, as indicated, display highly developed managerial skills in organising primary suppliers; maximising the efficiency of their work force and controlling logistics and delivery of products as and when required in a volatile market place. However, the continued use of large, manned production lines with operators performing simple repetitive tasks appears incongruous in this century and it is of interest to review some of the drivers for automation in the sector, as well as the technical and market challenges faced by the industry, and to explore where the balance might lie to influence the future direction of assembled food manufacturing.

Drivers for automation

In most manufacturing sectors, automation procedures have revolutionised the way products are made. Increased efficiency and consistency of manufacture with committed lower unit prices has created wealth that has driven modern industrial economies. It seems natural to argue that similar benefits could accrue from applying the same principles to the food manufacturing sector. The key factors are the economics of installation and the return on investment. As always this will be determined not just by the replacement of human operators and their personnel support structure but by factors such as consistency of output; reduction in wastage and reworking; ease of integration into supply chain and e commerce marketing procedures; product traceability and optimising the efficiencies of the entire process through the supply chain. A special factor in food manufacturing is the necessity for absolute hygienic operation and the separation of human operations from the process is an obvious benefit. Machinery can work readily at the low temperatures required and can be contained within specialised environments, such as inert atmospheres, to provide aseptic conditions influencing shelf life and preserving product value.

As in any case for automation the factors influencing return on investment are complex and application specific. However, it would be very surprising if food manufacturing proved to be an exception to the general rule of increased efficiency and wealth creation.

Challenges for the industry

In any path towards automation the food industry faces a number of organisational and technical challenges that will vary from company to company and even from region to region. Generally the manufacturer of assembled foods deals with a quite volatile market where there can be rapid changes in product design to meet customer demands. In the case of the manufacture of sandwiches, for example, even the variation of the weather from day to day will influence the order portfolio. The market itself is intensely competitive and very price sensitive. There is a lack of loyalty in the supply chain which is exacerbated by over capacity in certain product lines and, within the UK, by a recent contraction in the numbers of large retail chains. Competition is increasingly global and there is a constant pressure on margins.

Although many senior personnel in the sector are aware of the possible benefits of automation, the general response so far has been to stay with a labour intensive production model and meet the variations of the market demand by employing short term contract labour to smooth out the effects of large deviations from the production norm. Given a reliable network of raw material suppliers, efficient logistical support and good management this model has worked well. Within the present volatile market environment, capital intensive production is perceived to be financially risky, requiring a long term financial commitment and predictable return on investment that cannot presently be justified. A general lack of technical infrastructure on automation to inform management on capital investment issues is of course a factor in this assessment.

Such arguments for the status quo must however be balanced by the recognised difficulties of labour recruitment (bussing labour to factories from a 30 mile radius is not uncommon in certain areas); the inefficiency and cost of training when staff turnover is high; the stringent requirements for hygienic manufacture; increasingly rigorous health and safety and employment regulations; the increasing evidence of Repetitive Strain Injury (RSI) and the competition from present low cost procedures in the new European Union States as logistics and industrial infrastructure support from the EU gathers pace. It is thus timely to consider how the industry might evolve in the coming years to resolve this apparent dichotomy.

If automation is to provide a way forward in developing a long term sustainable industry, it is useful to review some of the technical challenges to be addressed. These relate essentially to the special factors that must be addressed in the manufacture of assembled food products, including:

• The requirement to pick and place soft, fragile, flexible, sticky/slippery products of dissimilar weights and shapes
• The need for hygienic manufacture which must be reflected in equipment design and in all maintenance and cleaning aspects
• The need for reconfigurable automation procedures that can be quickly adjusted to meet changing market requirements
• The development of appropriate automation procedures for the industry which meet its needs both in technical and financial ways
• A requirement for reliable automation inspection systems to ensure a consistent quality of output
• Technical infrastructure support to facilitate the transition of the industry from a labour intensive to a capital intensive operation. Such support must include training, technical awareness of the latest developments, demonstrations of best practice and the growth of a technically knowledgeable customer base

Present technical developments

During the last few years significant developments have been made in the design of grippers, or end effectors that facilitate the mechanical movement and placement of food products. Innovations include the development by AEW Delford of a precision gripper for the placement of sliced meat products; the precision manipulation of biscuit products using airflow procedures developed by Silsoe Research Institute; pneumatic non contact placement of small sticky objects by INBIS Technology and devices for the precision placement of tomato and cucumber slices developed at the University of Salford.

An extensive list of such developments, both in the UK and Europe, could easily be compiled but it is suffice to summarise that given a suitable engagement by the engineering community even some technical problems previously regarded as intractable by the food manufacturing industry can be successfully addressed. The cost benefit analysis and possible return on investment of the various solutions devised are important factors, but it appears that product handling issues are no longer a predominant factor in automating food assembly as was once supposed.

Currently, while there is an extensive range of specialised machines specifically designed for the food industry, there is a sparsity of general purpose automation equipment to meet the stringent hygienic requirements demanded. Successful adaptations have been achieved with robots such as the ABB Flexpicker, but many other configurations have proved less amenable to the harsh cleaning regime that is characteristic of the industry. Solutions based on the use of plastic shielding or the development of stainless steel cladding have been applied in the meat processing industry but appear to have found little appeal in the sector. Hygiene is such a key factor that automation equipment targeted at the industry should be specifically designed with hygienic operation as a key parameter and adaptations of current equipment regarded only as interim solutions.

Many food products enjoy long production runs and highly efficient production lines can be configured by linking a series of specialised machines for almost completely automated production from raw product input to packaging and palletising. In general however, the industry must cope with relatively short production runs to meet changing market demands and thus any approach to automation must incorporate significant flexibility, allowing a rapid change in product design. Such a requirement argues strongly for either the deployment of robots whose operation can easily be reconfigured by programming or the use of simple mechanisms which can be easily reconfigured within some intuitively simple modular system concept. Both approaches are feasible – the latter being less flexible than the former – but eminently suitable for many applications.

The major application of robotics has traditionally been in mechanical assembly, where use has revolutionised our manufacturing base. A vast array of robotic devices have been developed to meet industrial needs and they tend to be characterised by common parameters such as accuracy of placement, repeatability, speed of operation and load capacity. Today’s robots are extremely reliable and capable of long term, trouble free performance in pick and place operations and precision assembly. Such performance naturally comes at a cost and it is interesting to consider if cost reduction could be achieved if performance specification could be relaxed. Assembly of food products does not generally require the same accuracy as, for example, the assembly of car mechanisms and exact repeatability is unnecessary. In many applications a load capacity of approximately 1kg will suffice and a range of operations could be restricted to a fraction of a conveyor belt width. Speed of operation need only mimic average human performance.

Such relaxed specifications may argue for the development of a new type of robot that is flexible rather than stiff in construction, built of lightweight materials with a low inertia and safe for use in close proximity with human operators. Reliability and ease of cleaning must not be compromised, but programming must be simplified to produce anthropomorphic show-and-teach procedures compatible with existing operator skill levels in the industry. Such a design will present a challenge for today’s R&D engineers but, if a suitable device evolved that could be marketed at a fraction of the price of current general purpose robots, the impact on the food manufacturing sector could be significant and open up a major market for the machine suppliers.

An advantage of human operators on the production line is that the product is under constant surveillance as it passes down the line and such intense inspection guarantees the quality, of at least the visual aspects, of the finished product. Such a claim is undoubtedly true and supported by the constant stream of reworked products often seen in production lines. Full automation requires the use of automated inspection systems which must be totally reliable and ensure the quality of the final food products. Assembled food products in any batch are similar (or should be) but not identical and this poses interesting challenges in, for example, the design of suitable algorithms for the visual inspection systems.

Solutions could be based on neural network or fuzzy logic procedures, depending on the application, and applied to current commercial inspection systems. Applications will exist that present significant technical challenges to ensure acceptable levels of performance, but there is no reason to doubt that, as in the case of gripper design evolution, cost effective solutions will emerge once the engineering R&D community is actively involved and commercial motivation is available.

In general, the engineering skill base of the industry tends to lag behind that of other manufacturing sectors and significant technical support will be required if the industry is to adopt capital intensive production based on advanced automation procedures. Following the trends set by other sectors in the 1970s and 1980s companies could acquire highly skilled technical staff to ensure the efficient operation and maintenance of the equipment and also to act as a source of in house expertise to advise management on capital investment decisions. Academia and professional engineering institutions are well placed to provide the necessary training, backed by some central or regional governmental facility to give a focus to the process. Alternatively, it could be argued that the core skills of food companies lie in the design and marketing of their products and that the acquisition of expertise in robotics and automation lie outside their remit. In this case, the business model adopted recently by the transport and airline sectors, which involves only paying for the use of capital assets, may be appealing as the burden for technical support lies with the equipment suppliers who provide and maintain productive capacity.

Food factory of the future

Predictions on future technical developments must be made with extreme caution, but it is possible to extrapolate some present trends and see what may evolve. At the recent food manufacturing conference in Laval1 the increasing cost of energy was raised as an important factor influencing operating procedures and factory design in the sector. It is certainly not uncommon to see a relatively small, specialised production line placed in 2-3000 cubic metres of factory space that must be cooled, have a filtered atmosphere and be constantly cleaned and inspected for bacterial growth. Some companies employ up to 20 per cent of the core work force on cleaning duties and expenditure on the supply and disposal of cleaning agents can be significant. One obvious solution is, where possible, to restrict the controlled environment to the proximity of the production line by employing a containment. Such a concept is not new and was outlined at the Food Manufacturing Conference in 20022. The approach has recently been explored in more detail in a UK DEFRA LINK feasibility study3 and expanded to consider the development of modular sealed containment units with standard interfaces, service facilities, communication links and Human Computer Interfaces (HCIs) which could be configured to meet specific assembly tasks. Non standard atmospheric environments could be employed to achieve aseptic operation and the possibility of developing innovative products for niche markets. Reliability of machine operation, fault detection and ease of correction and redundancy within the design are key engineering issues when it is important to maintain barrier integrity and sustain production. Such issues are not uncommon in other industrial sectors, such as the nuclear industry, and there will be opportunities for effective technology transfer of existing solutions. A reproduction from one of our simulation studies is given in Figure 1.

Since the units would be relatively compact, 1-1.5m in diameter, they would be easy to transport and reassemble. This restriction in size could present problems for the installation of some existing processing machinery, but recent technical developments in process intensification, as applied, for example, to product mixing, that emphasise a constant trend to downsizing of equipment could address this issue.

Such concepts may well be thought somewhat futuristic at this time but they do offer possible solutions to existing problems and could contribute to the long term sustainability of the industry.

Conclusions

For various understandable reasons the food manufacturing industry has lagged behind other sectors in the introduction of automation equipment for food assembly processes, but there are many drivers for change. Given the size and diversity of the industry and the variety of market forces, a spectrum of solutions will inevitably evolve. In the future many small companies producing hand made products for regional and niche markets will still exist; as will manufacturers who incorporate manual production with islands of automation and there will certainly be fully automated manufacturing systems. It is increasingly clear however, that the current large, manually operated lines with scores of operatives performing simple, repetitive tasks in non ideal environments will no longer be viable. Their demise will be accelerated, inter alia, by demography, employment and health and safety legislation and the inability to compete in a changing market environment. Their present existence appears as an anomaly in our modern industrial society and their loss will not be mourned.

A key issue is the sustainability of a vibrant and crucial industry that must make a transition to modern production methods. Success will require cooperation between leaders of the industry, machine suppliers, research institutes and some governmental mechanisms which will provide support for the process. The goal will be a highly efficient, globally competitive, food manufacturing sector employing the latest technology whilst continuing to supply us with a wide variety of high quality, affordable products.

References

1. Food Factory of the Future 2004. Laval, France – October [[email protected]]
2. Food Factory of the Future 2002. Gotebury, Sweden – October [[email protected]]
3. Modular reconfigurable shelled robotic automation in food manufacture, UK, DEFRA BRIDGE LINK FT0619. 2003/4 [[email protected]]