REQUIREMENTS
The production process at a large bottling factory in Zagreb starts with producing PET bottles. The empty PET bottles are transported via hundreds of meters of air conveyor rails, and filled with different beverages and soft drinks at large filling carousels in the clean room. The carousels are capable of filling up to 46.000 bottles an hour. The full bottles are encapsulated and transported on to the packaging and paletting areas, from where they are trucked to the customers.
Cleaning of the machinery is done several times a day when production switches from one beverage to another using CIP processes. Also, there is ad hoc cleaning when a bottles breaks or spills occur which happens occasionally. Finally, there is a quarterly schedule for maintenance and cleaning where all machines are cleaned top to bottom. Cleaning of the carousels requires disinfection of sensible parts with alkaline cleaners on a daily basis.
Cleaning the air conveyor rails posed a particular problem: Empty PET bottles are held between two rails by the small ring under the screw cap and propelled by air blowers. The rails themselves are slippery and assure smooth sliding when clean. However, minute amounts of sugar in tiny droplets in the air are constantly deposited on the rails, and over time make the rails sticky. This results in a stick-slip effect, and after some time the bottle necks get stuck, the bottles smash into each other, and the entire production process is disrupted. This resulted in substantial standstill costs.