As ingredients are received, particle removal helps control product quality. Removing particles reduces the amount of material that could create off flavors. Filters in the housings marked “1” in the figure are chosen depending on the level of particle content in each ingredient. Performed using depth filtration media, the filters can remove visible particles (> 20µm) or smaller particles (>5µm) according to process requirements.
Many different bacteria and other organisms can enter the soft drink process. If necessary, they can be removed using membrane filters. These organisms can find their way into a soft drink container from two directions. The product itself can carry organisms that may have been introduced via ingredients, or the containers themselves may be contaminated by organisms from the environment or from the water used to wash and rinse them.
Filters in the housings marked "3" or "4" in the figure are in place to capture most or all of the organisms that might enter the system. The filters marked "3" are usually based on membranes with pore sizes of 0.45µm to 0.65µm. This filter captures the bulk of the organisms and protects the critical final “sterilizing” filter (marked "4") from being overloaded and fouling prematurely. The final filter is usually a membrane filter having a pore size rating of 0.22µm.
Ingredients may be stored in tanks before mixing and the final product is usually stored for staging before packaging. Filtration acts as a critical contamination control step - protecting ingredients and final product from airborne particles and organisms.
Carbonation using carbon dioxide gas may require filtration to prevent particles or organisms fom entering the container. If the gas supply is not guaranteed to be free of particles or bacteria, filtration acts as a barrier to these potential contaminants..
Hydrophobic membrane filters are used for both tank vent filtration and process gas filtration. The hydrophobic nature of the membrane prevents water droplets from collecting on and wetting the membrane, which would block the flow of air or gas. Blockage can lead to tank failure or reduced flow of process gas. The filters are most often made with PTFE membrane with a 0.22µm pore size rating.
Treated water is used as the main ingredient in most soft drinks. The treatment is the same in each facility owned or operated by a particular soft drink brand. That is so the drinks may have consistent flavor, no matter which bottling plant produced the drink.
Multiple filters are used in each water treatment system. Follow the link to see more about process water filters used for soft drink and other food & beverage operations.