The benefits of automating produce production lines

Packaging fresh produce presents challenges in terms of handling, food safety and shelf-life, so how can manufacturers deliver a high-quality product efficiently?

There are a number of influential factors which manufacturers must consider when packaging fresh produce. 

The characteristics of products, such as fresh vegetables and salad leaves, mean that gentle handling is essential to prevent damage and costly waste. Equally important is the need to retain product freshness.

Speed is key when moving product from delivery to shelf-ready packaged goods. This is particularly relevant for produce grown out of season to meet consumers’ year-round demand, which may have a shorter lifespan - and makes maximising freshness a priority. 

Variation in pack sizes also has an impact. The rise of single-person households, together with the drive to reduce food waste, has seen an increase in convenient, single-serve formats, while the economic squeeze has created demand for family-size value packs. Both target consumer groups want to see the quality of the product before purchase and be confident of its shelf-life.

Retailers can also add to the complexity of the production line by choosing to run seasonal or competitive promotional offers, such as 25% extra free, which must be accommodated quickly and efficiently.  

All this must be achieved while ensuring high operational efficiency effectiveness (OEE) and compliance with strict food safety regulations set by industry bodies and major retailers. Such is the pace and pressure of modern-day processing that fresh-produce manufacturers need to ensure production lines deliver on every level - quality, flexibility and productivity. These issues are driving innovative developments in packaging automation, where technology is being integrated into operations to improve performance. 

Quality and quantity

Processors can maximise product quality by selecting the right distribution technology to gently move products down the packaging line, thus removing the risks and potential errors associated with human contact. Innovations such as horizontal motion distribution systems can be used to transport dry fresh produce smoothly. 

Potentially wet or sticky non-fragile products can be moved confidently using a high throw conveyor, perfect for vegetables or loose lettuce which may otherwise stick to the pan. Conveyors which keep product contact to a minimum are essential in this type of application too. Gateless designs dispense with the traditional mechanical gate at the end of the tray and allow product to move freely and reduce cleaning time.

Streamlining can also be enhanced by integrating electromagnetic drives into the system, which eliminate moving or wearing parts such as shafts, gears, links and belts - benefiting costs as well as product integrity.

Of course, this focus on gentle handling is not at the expense of speed. Conveyors are designed to transport product both carefully and rapidly in order to retain its freshness.

Increased productivity

Bagged fresh produce is firmly established as a popular packaging format for consumers. Not only does it offer convenience, but the use of transparent film also enables the quality of the product inside to be assessed. As an exceptionally cost-effective and lightweight material, polyethylene is emerging as a reliable option to protect less-heavy applications. Automation technology has responded with a number of developments designed to enable processors to remain competitive.

Rotary impulse sealing systems now enable vertical form fill and seal (VFFS) polyethylene (PE) packaging machines to be used for a range of fresh produce. Product waste is reduced due to the optimised product transfer from the multihead scale through to the jaws. Standard single-jaw packaging systems have recently been superseded by innovative, rotary, double flat-jaw configurations which achieve twice the throughput rate.

Processors can also benefit from the huge strides that have been made in bagging speeds. The latest VFFS PE packaging systems, such as the tna robag FXIS 3ci, can achieve optimal speeds of 150 bags per minute (bmp) compared to the average 70-80 bpm of traditional PE machines.  

The tna robag FXIS 3ci vertical form fill and seal (VFFS) rotary polyethylene (PE) packaging system.

Versatility of bag size and format is also key. So too is the ability to adapt to a range of different products which are often processed in the same plant. This level of flexibility can easily be achieved with automated systems which do not require any mechanical adjustments when changing product or film.  

Increasingly sophisticated software underpins the packaging line and allows adjustments to be made from one central control point. Manufacturers can store a number of pre-programmed settings or make real-time changes electronically rather than having to manually take out a machine or line. This integrated technology also flags breakdowns or errors immediately; operators can address and resolve any issues quickly and avoid bigger problems backing up on the line. Downtime is kept to a minimum and manufacturers are able to respond even faster to changing market demands.   

Safety first

The 2011 E-coli outbreak in Europe hit the headlines and the fresh produce sector hard. It highlights the very real need for processors to have robust traceability systems in place to help protect both consumer safety and the reputation of the business. This is where automation is invaluable. 

By installing control systems that can be easily validated and incorporated into existing processing and packaging lines, manufacturers can gather essential tracking information throughout the entire process. Not only does this meet regulatory requirements, it brings added benefits in terms of better stock control and shelf-life planning; waste and costs are reduced, and product quality is maintained.

Data collection equipment, such as barcode scanning systems, can accurately verify that the correct batch is being processed by scanning the product and cross-checking it with available data. Data-code assurance systems ensure that the date code is printed, complete and legible, while stale product monitoring keeps output within specification.

Metal detection technology is one of the most sensitive and reliable in-line checking systems. Installed at key risk points in the line before packaging, this equipment operates effectively at high speeds to maintain productivity levels. Early detection also ensures foreign bodies can be removed without spoiling numerous batches and so helps to keep costs down.

The bottom line

Packaging fresh produce presents manufacturers with specific challenges and pressures. Retailer and consumer expectations for consistent quality can now be met more easily with greater investment in automation. Issues with raising productivity levels, reducing product and packaging material waste, as well as adapting to complex variations in pack size, format and content can all be addressed effectively with the right system in place. Crucially, by delivering measurable improvements in key areas, manufacturers can evaluate a tangible return.

In fact, the latest developments in automation technology and design go even further to address wider inefficiencies. Sustainability in terms of reducing energy consumption is an ongoing concern. New machines are designed to run using minimal air and power consumption, and also increasingly feature standby options within the software. Additional information on usage can be gathered by integrating sensing equipment, such as flow meters, motion sensors and kWh meters, into existing PLC-controlled systems; steps can then be taken to reduce unnecessary waste when data for a complete line is centralised and reported. Consideration is also given to getting the most out of plant floor space, with processing and packaging equipment now designed to be both compact and powerful. 

By reviewing the performance of existing production lines and systems, plant managers can identify priority areas for improvement and make the move towards greater automation and efficiency