The hygiene concept that KIC Krones developed and implemented for Starzinger’s Frankenmarkt plant consists of four parts:
The following is a detailed explanation of how these stages work.
To begin with, KIC Krones optimized the foam cleaning and conveyor lubrication systems on canning line 2. Where the foam cleaning process had previously used only alkaline and acidic detergents, it now uses three components to achieve better results:
The targeted cleaning of surfaces with acidic and alkaline media beforehand ensures that the disinfectant can work to optimal effect on the cleaned surfaces.
Foam cleaning of the filler is automated, while other machines and the floor can be cleaned using a foam cleaning rod.
The conveyor lubrication system uses a classic wet process, which was switched over to KIC Krones lubricants as part of the new hygiene concept. The change also benefits Starzinger in terms of environmental impact, as Nadine Prehofer explains: “On the new lines, we’ve introduced a workflow and valve controls that reduce water and resource consumption and keep contamination out of our wastewater.”
The following CIP (clean-in-place) procedures are customary in the industry:
In contrast, the new CIP procedure that KIC Krones developed works on the principle of intermittent dosing into the acid tank. The disinfectant is added ten to 15 minutes after the acid cleaning phase. Because the acid cleaning happens first, any mineral scale deposits are removed and the disinfectant can do its work to optimal effect on the clean surface.
In intermittent dosing, the disinfectant is divided into three equal parts. So it’s always fresh, unused disinfectant that is going in and disinfectant is supplied across the entire time allotted for sterilization. A pause of around 30 seconds between each of the three dosage steps ensures proper mixing.
Starzinger is currently running the new CIP procedure only on the upgraded canning line 2. However, the company plans to implement it across all lines in the future.
Redefining the treatment of process water in the tunnel pasteurizer, using chlorine dioxide, was a key aspect of the new hygiene concept. “Of all the technological advancements, the chlorine dioxide system was especially important to us because it solves the problem of pasteurizer hygiene. In the past, we used very aggressive chemicals from other detergent manufacturers. With KIC Krones’ solution, which uses a chlorine-dioxide system, we’re already seeing a significant improvement, even after just a short time,” says Nadine Prehofer.
In the tunnel pasteurizer, process water is recirculated. Various methods are available for treating this water, depending on the operating environment and the customer’s needs. Some of the commonly used chemical disinfectants are oxidizing agents. Unfortunately, when they are used, there can still be microbial growth in the recirculated water and formation of biofilm and odors. To address these issues, larger (often excessive) quantities of the oxidizing agents are used. However, that can drastically shorten the service life of materials and cause corrosion.
Previously, Starzinger had not used chlorine dioxide as a biocide in the pasteurizer because the conventional way of manufacturing chlorine dioxide, using hydrochloric acid, generates corrosive byproducts that damage stainless steel. However, KIC Krones doesn’t use hydrochloric acid to make its chlorine dioxide but rather a special sulfuric-acid-based product that results in no corrosive byproducts – without negatively impacting the disinfectant’s effectiveness.
However, because of its volatile nature, chlorine dioxide cannot be stored and must instead be produced on-site. For this, sodium chlorite from Krones’ colclean series is mixed with a specially optimized sulfuric-acid-based product in a generator. Although the generator makes for a higher initial investment, it pays for itself in the long term because the chemicals used are less costly.
There are various options for connecting the generator to the pasteurizer, depending on the pasteurization process used:
KIC Krones installed the latter option at Starzinger. Here, Krones colclean sodium chlorite and the sulfuric-acid product are mixed in the chlorine-dioxide generator. The chlorine dioxide is then fed into the pasteurizer by way of devices that not only distribute the chlorine dioxide but also monitor the two components for volume, pH, and redox potential. The result is optimal distribution and dosing for every application and all makes and models.
