The word hygiene can cover both the need to keep everything clean and to avoid cross-contamination of ingredients.  Manufacturing systems that were suitable a few decades ago are now proving to be cumbersome and not at all flexible to meet the demands of todays marketplace. To remain competitive, it is necessary to offer a vast array of products to the consumers. This means that manufacturing processes need to be agile to ensure that only the right amount of product is manufactured at the right time and that you are not creating Inventory to do so.

Traditional long pneumatic conveying and coupled mixing lines represent a major risk. These are awkward to clean, and thoroughly removing any trace of a previous recipe is very time consuming.  When this is completed how can you swab test each surface to ensure it is safe?  Commonly entire shifts can be used for cleaning down, before a change of recipe is allowed, which adds significant costs to the finished product and inflexibility to the production line.

In order to reduce costs and keep the number of clean-downs to a minimum, some companies opt for Campaign Manufacturing: setting their production schedule to start with the blandest recipe and getting progressively stronger. This is often referred to as white to black, but this just results in Inventory and has its own risks of wastage in respect to shelf-life expiration.

A REAL CASE FOR HYGIENE

A major manufacturing company, Brothers Illong, who supply the Chinese dairy industry with specialty raw materials and blends to manufacture high quality products for both children and adults, was facing these hygiene issues. With a backdro of a number of scandals in the Chinese dairy industry at that time, they put hygiene and clean-ability top of their list when looking to invest in expanding their production capacity.  They certainly didnt want to find themselves in the news headlines.

At the time of their expansion, they had four static ribbon mixers of different capacities ranging from 500 kg to 3000 kg, which matched their order requirements and were designed to keep downtimes to a minimum.  They used 6 operators per shift to keep all the mixers running and they tipped all pre-weighed materials from a mezzanine floor directly into the mixers, ingredient by ingredient. The mixing time was uncommonly long at 1 hour, with a poor flowing product taking longer at 1.5 hours.

After mixing, eight operators were then required at the ground level to execute pack-off. During this pack-off time, the mixers are standing idle and not adding any value. In addition, the eight operators could only work on one mixer at a time, so the other three mixers had to wait their turn, wasting even more production time. This made it impossible to keep the mixers at a high OEE rate (Overall Equipment Effectiveness). The production process was very complex to manage as there were too many quality control points and the 14 operators were working in a busy, dusty environment.

Companies that have found themselves in a similar situation have attempted to break up the long pipework or in-line processing equipment by using tilting aluminium totes and/or big bags. They have continued to use the large ribbon mixers, but removed the pneumatic pipework, and used the containers to collect blended material from the mixer and deliver it to the packing lines. This enables the mixer to go straight into cleaning as soon at the last bit of powder has been discharged. This relieves some of the bottleneck, but tends to transfer the problem elsewher in the process.

Due to the open transfers and open-mouthed discharge points of totes and big bags, excessive dust is generated within the working environment. This now means that large-scale cleaning from ceiling to floor needs to be done, resulting in unnecessary utility usage as well as risking the fabric of the building itself, and still, the critical contamination points may not be cleaned. In a bid to overcome this, dust extraction has been employed but is often overused, which has then led to poor product yields and moving the problem on further down the line.

When Brothers Illong decided to make a capital investment to increase their production, they decided to buy high quality equipment, and chose a system that was already being used by many international infant formula producers.  After a reference visit and full-scale testing using their own ingredients, the contract was granted to Matcon. The final solution involved creating four discrete process modules:

• FILLING: The sack-tipping unit with sieving is designed to enable dust-tight filling of the Matcon IBC (Intermediate Bulk Container), ensuring a fully contained transfer of material into the container without spilt material. Thus, high hygiene standards are met and contamination risk is reduced.
• MIXING: Using an IBC system means that the product is mixed directly within the container itself, so there is no product contact with the blender and no risk of cross-contamination when new containers are mounted on the blender.
• PACKING: The packing system comprises a high-accuracy auger filler fed from an IBC on the floor above. Level probes in the Auger hopper automatically call for product from upstairs. Cone Valve technology within each of the IBCs means that the blended material is protected against segregation during discharge. This ensures a quality product every time. Dust-free transfers maintain the safety element of the system.
• CLEANING: IBC Cleaning provides a quick and safe cleanout at recipe changeover. IBCs are washed off-line from the main manufacturing line so it does not contribute to production down-time.

Because all these manufacturing steps are separated/decoupled, each processing step is independent and can take place simultaneously, resulting in a lean, efficient manufacturing system with high OEE rates.

Brothers Illong found that by using a Matcon IBC Blender, batch sizes of up to 1600 kg can be processed much more quickly than before. Because the product stays within the container and there is no product contact with the blender itself, changeovers are virtually instantaneous. Brothers Illong have the capacity to run 3 to 4 batches per hour off the one single IBC Blender, even being able to change the recipe for each batch if required, without the need for a clean down. The IBC blender is able to accommodate different container sizes which can be matched to the batch size. There is no further need to store excess product and tie-up cash—the ultimate in manufacturing flexibility and efficiency.

The amount of manpower they require has been halved, with just three people now needed for filling – one at blending and three at packing. This new team structure can produce 20 tonnes in a single shift, meeting the same capacity as that of the previous system, whilst allowing for future sales growth. They are also able to perform the cleaning duties during their usual shift, wheras before, they had to work overtime.

SMALL BUT MIGHTY 

The decoupled modular design of a container-based system means that Brothers Illong have the ability to increase production volume by adding in extra packing lines, whilst still running with just one IBC Blender. The upside of using a container-based production system is that one blender can feed to many packing lines—the containers are simply sent to wher there is a call for product.  This is unlike fixed pneumatic conveying systems wher one mixer is linked to a single packing machine.  Should demand increase further, a second IBC Blender can easily be integrated into the system.

MILK AND WATER DONT MIX

A clearly defined hazard in dairy installations is the risk of microbial contamination. If all traces of moisture are not removed from the system, there is a danger that bacteria will grow in these droplets and contaminate the whole process. With pneumatic conveying or continuous mixers this can result in a very large batch of product that has to be scrapped. At what cost to both your reputation and operations?

Matcon has been working with leading manufacturers installing our IBC systems, which overcome these issues thanks to not only changing the conceptual solution in terms of decoupling the system, but also due to the simple nature of the IBC design itself. Firstly, because all blending takes place within the container itself, there is no time-consuming cleaning of a mixer after each recipe, the blender is simply ready immediately for change after change, switching out each container with no product in contact with the blender. These dirty IBCs are then cleaned off-line, away from the production area.

At the Brothers Illong site, they use wet washing to clean the IBCs, but because this takes place off-line there is no risk of waterborne contamination. There are sufficient IBCs in the system to ensure there is plenty of drying time before the IBCs go back into circulation.

THE FULL BENEFITS

Brothers Illong now have a fully hygienic yet flexible manufacturing plant. Production throughput has doubled, yet the number of operators has been reduced by half. This has resulted in the most efficient and hygienic dairy facility in China—a show-piece which satisfies both their customers and the stringent Chinese legislators.