Fresh milk and cream: increasing capacities for returnable bottles

New technology – the details

Bottle washer dimensioned for long treatment times

If production is to be divided into a dirty area and a clean area, a double-end bottle washer must be used, in order to provide a spatial separation between bottle infeed and bottle discharge. The new hall is divided into two sections by a ceiling-high wall running over the hall’s entire width. The bottle washer goes through an aperture in this wall sealed off by a stainless-steel frame. That neatly separates the bottle washer’s clean end from the rest of the hall. The Lavatec itself has been specifically designed to comply with the highest hygiene standards and is completely made of stainless steel, including important components. “We are manufacturers of premium products, so stainless-steel surfaces are first choice for our filling lines. That was very important to us. After all, we want to keep the line in good and presentable condition for a long time to come,” explains Paul Althammer. “Krones was able to satisfy this wish. What’s more, it was their overall concept that won us over.” The Lavatec D4 has a fair bit of work to do, in order to remove all the many fat and milk residues from the bottles that enter the machine. So the containers’ dwell time in the caustic section must be correspondingly long. To guarantee these long treatment times, the washer is particularly large. The bottle pre-treatment zone has been designed to prevent severe foaming, despite the lactoproteins’ marked propensity to foam. Hygienic design principles have been rigorously observed throughout the entire line: There are no corners or edges where residues might collect, and the discharge profiles guiding the clean bottles onto the conveyor belt are made of biocidal plastic, thus avoiding any recontamination. The Lavatec works with two caustic baths. The first one rinses off most of the soiling, and therefore the second caustic bath is hardly soiled at all. This two-chamber system substantially reduces the dirt load in the wastewater tank. Overall, the new bottle washer consumes half the amount of fresh water previously needed and significantly less chemicals.

*The Lavatec D4 reliably removes all fat and milk residues from the bottles.*

Rinser/filler block: maximised standards of hygiene

The rinser/filler block has been designed to ensure that retailers reliably get a shelf life of eight days for fresh milk produced using traditional methods and to also provide an option for achieving longer shelf lives. “Krones was actually the only company that could offer the machine technology able to meet this stipulation,” says Althammer. “What’s more, we’d gained very good experience with our old Krones filler block.” The block consists of a Modulfill NWJ filler and an electronic twin-channel Moduljet rinser and meets the highest of hygienic requirements. A cleanroom roof fitted with HEPA air filters generates a cleanroom atmosphere during filling. In addition, a partition wall between filler and rinser prevents possible contamination caused by splashing from the rinser. The hygiene concept also includes a comprehensive automatic intermediate foam-cleaning function. The Modulfill has been equipped with non-contact filling valves for milk processing that also meet the hygiene standards for aseptic lines. Despite the difference in weight between the one-litre bottle and the 0.5-litre bottle and in the specific weight of cream and milk, weighing cells ensure accurate fill quantities for both products.

*A cleanroom atmosphere is created in the rinser/filler block, thus ensuring a product shelf life even exceeding that required for traditional fresh milk.*

The rinser/filler block was quality-acceptance-tested by the dairy together with Krones’ validation team. Elaborate tests served to verify the stipulated best-before period and the suitability for ESL milk. To this end, UHT milk was monitored for sterility, filled and then checked. “Today, the line provides everything we’d hoped for,” says a satisfied Paul Althammer.

Filling low-fat and full-fat milk and even cream with 32 per cent fat content on one and the same filler was a genuine challenge. Low-fat milk causes severe foaming and has to flow in slowly at first. Cream, by contrast, must not be allowed to turn into butter and must therefore flow out slowly through a maximally large gap. The Modulfill, with its 45 valves, has a larger diameter than actually required for this output, in order to ensure a somewhat longer filling time for low-fat milk. The concept is working, says Althammer: “Milk is a natural product, its ingredients are not always the same and change, especially when the cows’ diet changes in spring and in autumn. Therefore, we had to reset new speeds every day for the low-fat milk in the old line. When low-fat milk was handled on the new filler for the first time, all of us could hardly wait to see how it would cope – and we were thrilled: There weren’t any problems at all. A perfect performance. Today, we simply set 12,000 bottles per hour, and the machine does the rest.”

Krones was actually the only company able to offer a rinser/filler block in the quality we need for fresh milk. Erwin Hächl Paul AlthammerDeputy production manager

Another vital requirement was fast product change-overs. The line fills six different fresh-milk products and is changed over several times every day. The Demeter milk, in particular, must not contain any traces of other products. “Change-over processes have to be perfect, with minimised wastage. After all, we’re dealing with a valuable raw material here,” says Althammer. Milk is used for rinsing to avoid any unnecessary standstills. But the “rinsing milk” is not wasted since it is drained into a special collecting trough installed in the filler, so that it can be processed to make other products.

Labeller: perfect dress for a top-quality product

The Ergomatic labeller, including a Checkmat EM inspector and an inkjet date printer, is the line’s third component supplied by Krones. This machine applies the striking green and blue labels of the Berchtesgadener Land dairy to the bottles. “It is important to us to present our precious Demeter and mountain farmers’ milk in perfect dress. With individual bottles standing in the refrigerated display cases, the first thing that catches the customers’ eye is the label and the bottle. So that has to be spot-on,” emphasises Althammer. “We started working with a Krones labeller in 1990 and bought our second one six years ago. So our mechanics and line operators are familiar with the machines, another vital aspect,” is how he explains why the dairy opted for Krones.

The labeller must be relied on to fold the tamper-evident label straight down at a high speed.
The inkjet system prints the best-before date on the labels.

The challenge involved here is the tamper-evident label, which reaches from the bottle’s cap down onto the bottle. It must be glued to the cap and then folded straight down onto the bottle at a high speed. Cold glue is used here, although its adhesive power on the cap is lower. That’s because flaming the bottle cap was not an option as it could adversely affect the milk. “When the cap is flamed, the bottle’s head space is heated up but we don’t want to subject our product to that,” explains Althammer. “It was a joint effort but we managed it all right,” he adds, satisfied. The flat thin labels are glued onto the bottles with the same glue and brushed on. After that, the inkjet system prints the best-before date on them. The integrated Checkmat is the final station in the line where every bottle is inspected one by one before being packed into the transport crate. The high-resolution cameras check all bottle types for correct label placement and for imprint of fat contents and best-before date.

Everyone who’s seen the new line so far was thrilled, saying it has turned out a real success. Erwin Hächl Paul AlthammerDeputy production manager

The final acceptance test for the new returnable-glass line took place in July. The old bottling line had been dismantled quite some time ago. The dairy soon felt safe to take this step, relying on the new line, and the space was urgently needed. That has given the Berchtesgadener Land dairy a bit of scope for fresh-milk handling, demanding as that is. Paul Althammer is satisfied: “We did not have much room to accommodate the new line but it has been fitted into the space available really well. Everyone who’s seen it so far was thrilled, saying it has turned out a real success.”

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#Milk #Glass #Filling #Europe

Christine Rüth

11. August 2022

11:35 min.

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