Producing infant formula is complex. It takes several processing steps and a host of individual ingredients to make a healthy infant formula in powder form. The spray towers where the liquid mixture is dried is the heart of the production process.

Once the formulation has been determined through various tests and trials, the regular production process begins with the successful initial production. It takes place in a closed system to ensure the highest-quality final result, with the milk subject to various processing steps.

Pre-treatment of milk

First the milk is pasteurised. This involves a gentle heat treatment to kill off pathogenic germs. The pasteurisation also deactivates enzymes that could adversely affect the milk fat or protein in storage. The milk is then concentrated at negative pressure and therefore at low temperatures. This procedure retains the healthy components of the milk. Now the milk or milk concentrate is ready to be processed further into a customised product.

HOCHDORF moves with the times, investing in the latest technology and new facilities. Following the state-of-the-art high-bay warehouse in Sulgen, the new production and filling line for infant formula went operational at the same site in 2018.

The mixing is key

The various liquid and powdered ingredients for infant formula such as milk concentrate, whey proteins, lactose, minerals, fats, trace elements and vitamins are mixed fully automatically. The sequence in which the ingredients are added, the temperature and the amount of time the mixtures are allowed to stand are crucial for the properties of the dried end products. The “wet mixture” is homogenised again before spray drying so that the fats and the other additives are mixed in equal measure with the milk concentrate.

Gentle spray drying

This is followed by spray drying in one of our three infant formula spray towers. Tower 9, which is the most modern facility, is located in Sulgen. It stands at 25 metres with a diameter of 11 metres. In the spray-drying process, the mixed concentrate is atomised to a fine mist in the upper area of a cylindrical spray tower at high pressure.

The many tiny drops enlarge the surface greatly, resulting in fast water delivery to the drying air. Air that is cleaned, conditioned and warmed up to 200 C° flows through the spray tower. The drops sink and the water evaporates at the same time, resulting in a fine powder.

Spray drying is a very gentle process. Because the evaporating water cools down the milk substance, the powder itself is hardly heated. The powder is then further dried using a fluid bed before it is ready to be packed.

Captions
Header: Internal and external fluid bed at Spray Tower Line 9 in Sulgen. (Photography: Daniel Hurter)
Intext: Automatic small component feeding station for tower 8 and 9. (Photography: Daniel Hurter)