Evaporated milk in PET – aseptically filled

As one of the world’s biggest dairy cooperatives, FrieslandCampina has always endeavoured to master the balancing act between running a safe and dependable production operation and using state-of-the-art technology. Back in 2014, the company decided to install dry-aseptic technology in its production facility in Aalter, Belgium for aseptically filling milk and dairy products in PET containers. At the time, it was one of the first Contipure AseptBloc DN systems delivered by Krones, with preform sterilisation, reduced consumption of sterilisation medium and reliable results. Line 1 produces 36,000 containers per hour. FrieslandCampina has now brought an almost identical dry-aseptic line from Krones online, this one rated at 24,000 bottles per hour.  

The facility in Aalter, located halfway between Bruges and Ghent, is the biggest of FrieslandCampina’s three production sites in Belgium. It is the European hub for longlife milk and milk drinks in cardboard and PET for brands like Campina, Joyvalle, Cécémel, Fristi and Nutroma. In Aalter, a total of 11 cartoning lines are running, three lines for white HDPE containers, three lines for small 7.5g portion packs and now two aseptic PET lines from Krones are all up and running. The production location in Lummen is known for its cream specialities under the Debic brand. The plant in Bornem specialises in longlife dairy drinks. 

The plant produces longlife milk and milk drinks for the European market. This also includes evaporated milk, which has so far been filled in small glass bottles. However, these non-returnable containers no longer met the company’s sustainability criteria, since it has pursued a strong sustainability policy along the entire supply chain for years – “from grass to glass,” as it would call the idea. 

Deciding on rPET 

FrieslandCampina was the first dairy company in Belgium to use recycled PET. To be more precise, containers made of 100 per cent recycled PET (rPET) in order to reduce consumption of virgin PET, and thus new raw material. Another advantage that plastics (no matter whether virgin or recycled) have over glass is their considerably lower weight. The PET containers for evaporated milk, which range from 200 to 500ml in size, weigh between 10 and 16.6g. For special markets, FrieslandCampina uses multilayer preforms weighing 12.5g.  

Additionally, the PET containers are dressed in a sleeve, featuring a “zip” over its entire height. This perforated line simplifies recycling because the zip enables consumers to separate the sleeve quite easily from the container before placing each in its appropriate bin.  

Besides its focus on more sustainability, a second major criterion for the purchase of the new line was that filling capacities urgently needed to be upsized, since the existing aseptic line with the Contipure AseptBloc DN was running 24/7 – and product demand kept on rising. 

100 per cent sterility 

Brecht Deleu had already assisted in putting in place the first aseptic line from Krones in 2014 and was also one of FrieslandCampina’s project managers for the second line. This time he became actively involved in the layout work. In his view, the fact that Krones had meanwhile implemented some essential improvements was an advantage tipping the scales in the company’s favour. “Everything we’d commented on with regard to Line 1 was taken into due account and optimised for Line 2,” he says.  

Deleu notes some examples: “Closure feed was one thing that was improved. In Line 1 the closures are kept in the sterilisation medium for only 13 seconds. Now, thanks to a helical infeed, they stay in there for an entire minute,” is how he describes one upgrade. “Preform handling was likewise improved, and the blow-moulder is designed for more user-friendliness overall. On Line 2, it now takes just one hour to replace the moulds (and not five hours as before) because the routine has been automated. But the most important result for us is that the line’s microbiological safety was increased even more. We checked 60,000 bottles, and none of them was unsterile. You can’t get any better than that,” he says. 

The line is run by only three operators, one each for the blow-moulder/filler block, for the labeller and for the packer. “The operating staff were already familiar with Krones technology from their experience gained with Line 1. That is, of course, a major advantage,” says Deleu. 

Ramping up 

The line was installed in December 2020/January 2021, with the first microbiological tests were performed in February. “We had a very good ramp-up phase,” explains quality assurance specialist Lisa Moeyaert who is responsible for validating new installations. “There were no microbiological problems, and all products were sterile. The blow-moulded containers’ quality has been very good – material distribution in the stretch blow-moulding process is spot-on. That’s important for the ‘topload’, meaning the containers’ stability during transport, with six to seven layers stacked on a pallet. Nor were there any complaints in regard to the quality of the screw-caps and the way they were put on top of the bottles,” is her verdict. 

Each container format was first validated by FrieslandCampina before it was released for production. Since May 2021, the process is finished and all products and formats have been acceptance-tested. Various inspection and monitoring systems provide production-concurrent quality checks and quality assurance: Three Checkmat units automatically inspect the containers for correct fill level and correct closure and label placement, and the PreformCheck unit in the blow-moulder monitors preform quality. “The most important thing for me with regard to validation was that the Krones team was here on the spot, so we could perform the tests together,” says Moeyaert. 


The line has been validated for a continuous production time of 72 hours without interruption for cleaning. “At present, we do not need any more than that because we don’t fill one and the same product for longer than three days running,” explains Moeyaert. Depending on the products involved, the line is changed over two to three times a week. Changing over both product and format takes about four hours, just changing the format one to two hours. 

The new additional aseptic line gave a significant boost to FrieslandCampina’s production flexibility. The line handles small portion packs, a total of seven different sizes between 140 and 500ml. All products are milk-based and have been sterilised before they are filled, the most important being evaporated milk in 140, 300 and 500ml containers for the Belgian and Dutch markets and the countries in the Middle East. The line also fills evaporated milk as private labels for retailers. 

In addition, the line processes the same products as the first aseptic line, which is installed right opposite Line 2:  

  • Chocolate milk in 200ml containers 
  • A strawberry-flavoured fermented milk-based drink, likewise in 200ml containers 
  • Flavoured milk in 400 and 500ml bottles for the UK market 

New maintenance strategy 

Since their cooperation started with the commissioning of the first PET line in 2014, FrieslandCampina and Krones have jointly developed a specially optimised care and maintenance concept. A service agreement has been concluded both for Line 1 and Line 2, which covers maintenance and exclusive spares supply. “Last year, we changed the maintenance-interval strategy,” says Delphine Haelewyn, the maintenance supervisor. “There used to be just one maintenance routine per year for Line 1, which took 15 days. Now we’ve scheduled three maintenance routines each for both Line 1 and Line 2 in one year, each of which lasts five days. And these routines are no longer carried out by Krones alone – we’re handling them together now.” The result: After one year with the new maintenance strategy, unscheduled standstills went down by 30 per cent, with the lines’ performance levels higher than before. 

One of the world’s biggest dairy cooperatives 

FrieslandCampina is owned by around 17,000 dairy farmers from the Netherlands, Belgium and Germany, organised in a cooperative. The dairy cooperative runs facilities in 38 different countries and has a payroll totalling about 24,000 people, which ranks it among the world’s biggest dairy cooperatives. The four business lines are subdivided as follows: 

  • Food and Beverage
  • Specialised Nutrition
  • Trading
  • Ingredients

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