Pre-stacking is an industrial term which describes pouring liquid into a container, generally prior to subsequent processing. Usually the liquid in question is a raw material. This procedure is particularly well known in the case of milk production.

Milk production

In milk production, pre-stacking is a very familiar process. After the milk tanker has driven to the individual farms and pumped the milk into its transport tank, it’s transported to the dairy. There, the milk is briefly inspected and subsequently poured into an initial storage tank. This storage tank is also called a pre-stacking tank. Before the milk can be processed, it needs to be inspected again. Subsequently, the raw material, in this case the milk, can proceed onto production. As milk is a fresh foodstuff that needs to be cooled, the pre-stacking tank must also have a temperature regulator so that the milk doesn’t turn sour. It’s important for the temperature to remain stable so that the milk isn’t subjected to any fluctuations. If a pre-stacking tank is used in milk production, it also serves as a foodstuff tank at the same time and, accordingly, must fulfil some conditions.

Pre-stacking tanks in other industries

Pre-stacking tanks are mainly needed in industries which process raw materials and need to store them individually prior to processing. For example, in the cosmetics industry, substances that are needed for the production of creams can be individually stored in a pre-stacking tank before a machines puts them together and mixes them in another tank and/or heats or cools them.

Hygiene and cleanliness of pre-stacking tanks

Hygiene and cleanliness are particularly important for all tanks that come into contact with foodstuffs or other sensitive raw materials. Intermediate parts that connect individual tanks, i.e. hoses, pipes and valves, must also be continually inspected for cleanliness and regularly cleaned.

Cleaning can be carried out using what’s known as the cleaning in place method. This method describes a cleaning process which can be performed in a single pass and connects several stations in the production process. This does away with the need to disassemble individual tanks and automatically cleans the intermediate stations thoroughly.