Top ofthe line

As the fastest man on Earth, Jamaican sprinter Usain Bolt is often the first human who springs to mind when people think of speed. Although Bolt will not be competing against conveyors at the upcoming London Olympics, speed is just as essential for conveyors in the food and drink industry as it is for him.

And they're getting faster. Conveyors are now being designed to be quicker to clean and to be more compatible with automated systems that improve the overall speed of a production line.

Conveyors designed for quicker cleaning are spreading to all areas of food production, says Adrian Smart, md of equipment supplier, Astec Conveyors. Many firms previously used mild-steel, powder-coated conveyors in low-risk areas, such as where food has already been placed in primary packaging. Although more difficult to clean, they were a cheaper option, he adds.

But now manufacturers are dropping them in favour of more expensive options that are easier and faster to clean. Stringent safety standards mean food manufacturers are looking to place conveyors made from materials such as stainless steel and ultra-high-molecular-weight polyethylene throughout all areas of their factories. This has enabled them to maintain or improve hygiene while cutting the amount of washdown time, Smart says.

Best practice​

Manufacturers want equipment that complies with systems of best practice for hygiene in processing such as hazard analysis critical control points (HACCP). Because of this, they are using more conveyors made of high-grade stainless steel that have had special finishes added for easier cleaning, says Clive Silverman, sales manager at Volta Belting Technologies a manufacturer of extruded thermoplastic belts. Rough finishes and sloppy welds with a tendency to rust used to be prevalent on conveyors in the food and drink industry. However, they have almost completely disappeared, he adds.

Designs are also being improved with a view to cutting cleaning times, says Chris Rice, md of equipment supplier, Optibelt. For example, equipment suppliers are working with food and drink manufacturers to avoid tight bends in conveyors because they are an easy place for dirt to collect, he adds.

"Hygiene will continue to improve,"​ says Smart. "Food and drink manufacturers are always looking to be innovative and increase standards by making it easier to clean conveyors."

The same trend for easier- and quicker-to-clean materials and designs also applies to the conveyor belt, says John Thompson, technical sales representative at Belt Technologies Europe a manufacturer and supplier of stainless steel belts. Manufacturers in the food and drink industry are turning away from belt materials that are hard to clean such as mesh alloys. Although mesh is easily repaired and enables air to circulate around a product which is important when cooking the difficulty of removing crumbs and particles makes them unhygienic and time consuming to clean, he adds.

Manufacturers want belts that are designed to be easier and quicker to clean, while still complying with HACCP procedures, says Silverman. For example, food and drink firms are ordering custom belt designs that have rounded drip-off edges that allow cleaned belts to dry faster. These allow hygiene standards to be maintained while cutting cleaning time, he says.

Firms also request belts that have been specially manufactured to give a uniform surface with no indentations or blemishes, adds Carl Johnson, md of belt manufacturer, Chiorino UK. This helps them conform better to HACCP procedures, he says.

Maintaining or improving hygiene standards while cutting the cleaning time required for a conveyor line and its belt have become key trends in new conveyor installations. "Manufacturers are trying to replace every area of production that is in contact with food with something more hygienic and easier to clean,"​ adds Silverman.

Volta recently placed new quick-release belts in a poultry processing facility. These could be washed in situ rather than needing to be removed and soaked as was the case with the processor's previous belt. Instead of using nearly an entire shift to clean, a washdown could be completed in minutes. "Cleaning and sanitation should be measured in minutes not hours,"​ advises Silverman.

Quick-release options on conveyors that relieve part of the belts' tension, enabling them to be lifted and cleaned in place are increasingly becoming standard, says Roy Fowler, sales director at equipment manufacturer, UPM Conveyors. "Customers are insisting on this because they cannot tolerate any unhygienic residues left at the end of a production shift."​

As time devoted to cleaning is cut in favour of production, electrical conveyor components must also be better able to resist full washdowns, he adds. UPM recently installed IP67 standard conveyors throughout the Hampshire production facility of meat and poultry processor, Pinnacle Foods. The machines conform to the international rating code that guarantees protection from a washdown by a high-pressure hose. "Cleaners will turn factory floors into swimming pools, so your equipment has to be able to deal with that,"​ he says.

Automation integration​

And while conveyor and conveyor belt designs can help to decrease the amount of time food and drink manufacturers spend cleaning production areas, there is also an increasing need for them to keep up with new demands from automation in production.

Equipment suppliers have had to increase the capability of conveyors to match these new demands, says Smart. This has been most noticeable at the palletising stage where robotic palletisers have largely phased out manual loading, he says.

For example, new conveyors can be programmed to selectively turn certain boxes. This allows them to start forming the palletising pattern before reaching the end of the production line. A robotic palletiser is then able to pick up an entire row at once, greatly increasing the speed at which boxes can be cleared off the end of the line, he adds.

This is also true for changing between different-sized boxes, Smart says. Previously, manufacturers would have to manually switch the guides on a conveyor to match new box widths when switching between different-sized packaging containers. However, conveyors have now been developed that can be programmed to do this at the flick of a switch, he adds.

This enabled a drinks manufacturer that Astec worked with to significantly cut the amount of time it wasted changing specifications between different production runs.

"A few years ago manufacturers may have spent multiple hours conducting a changeover. Now they specify that it can be done in half an hour at the most on new lines,"​ he says.

The system can be used with a variety of packaging lines but is largely limited to the drinks sector at this time, Smart adds. However, more food manufacturers are looking for any idea that can cut the downtime between production runs and he expects to see similar systems implemented in other sectors in the future.

Conveyor innovations are also being used to correct mistakes that automation introduces into a production system. If not caught, these can significantly slow down the overall speed of a production line.

The Leicester factory of Walkers Snack Foods had trouble with automatic palletisers dropping loads of product on the floor, says Smart. Occasionally a box would go down the line that had not been properly sealed on the bottom. When a palletiser then picked the box up, its contents would end up on the floor slowing production while it was cleaned up.

In response to this, Astec installed a conveyor with a vision system capable of checking seals on the bottom of the boxes as they went past. If the tape that was meant to be sealing a box shut was missing, the box would automatically be sent down a reject-shoot to be properly taped and put back onto the line, he adds.

Demand for innovations such as fully transparent conveyor belts is rising because manufacturers are recognising how vision systems embedded in conveyors can help with automation, says Rice. They can be used to pick up any product that does not conform to the required specifications, such as damaged goods or foreign objects.

As the price of vision systems continues to fall and their precision continues to increase, the trend will accelerate, he adds. "It is quite surprising how accurately and quickly vision systems can already look at products coming through a conveyor system to spot items that do not conform."​

As automation and efficiency on production lines increases, so will the need for better conveyor design. Reducing cleaning and changeover downtime will help increase productivity. Meanwhile, reducing potential mistakes resulting from automation can help cut costly product damage and delays in getting goods out of the factory. After all, those chicken nuggets Usain Bolt claims give him the ability to run so fast need to arrive on time.