TetraPak Packaging Case Study

By Oliver Gaskell

TetraPak is a packaging solution, developed by Dr. Ruben Rausing in 1951. Around that time, in Europe, milk was filled into glass bottles in a dairy, which were shipped to shops, where they were sold. After consumption, it was law in most places that the bottles be washed and returned to the shop for reuse. This approach had many problems:

  1. Firstly, the milk bottles weighed more that the milk itself. For every 1kg of milk, about 1.18 kg of packaging was used. This meant a truck with a specific weight limit was severley limited to the amount of milk it could carry.
  2. Secondly, it took unnecessary effort and water/soap for the containers to be washed and returned. They also then had to be returned to the dairy. Not only did this require more shipping, but it was very unsanitary.
  3. Thirdly, many staff were needed to operate the dairy. The bottles would have to be washed, then loaded into a machine continuously, loaded into crates and finally placed onto a truck.
  4. Also, most filling machines poured milk into a container in open air, so the milk would foam turbulently, limiting the production speed.
  5. Furthermore, if the machines ran out of bottles, milk would be spilled everywhere. This is a waste, and reduces profit.
  6. Finally, the bottles used space very inefficiently. The tapered top to the bottles created air spaces around it during transport, which could be taken up by more product, increasing profit per shipment.

The original TetraPak solved all these problems:

  1. The packaging was made from paper and plastic, and weighed very little. Per 1kg of milk, there was just 0.28kg of packaging.
  2. The packaging could simply be binned or recycled after use. This meant no washing or returning of containers. Also, the inside of the paper doesn't touch the machine so it is very hygenic.
  3. Only 1 person was needed to operate the whole process. The roll of paper would be loaded onto the machine, then the crated would simply have to be placed onto the machine empty then removed from it when full. The machine would automatically place the milk cartons into the crates in the most efficient way possible.
  4. The containers were filled below the surface of the liquid, so there is no foaming.
  5. The machine automatically shuts off if the paper supply runs out, wasting no milk.
  6. The specially shaped crates would both fit the milk cartons perfectly, utilising 100% of the space in the crate, and would also stack and fit nect to other stacks with no space in between. The only empty space was at the bottom, in the gap created by the shape of the crate, resulting in a nearly 99% space efficient transport.

It worked by first forming a tube from the plastic-coated paper, (which was heatsealed) then continuously filling and forming tetrahedrons (which were also heatsealed) with 3000-4000 lbs of force, to ensure a perfect seal.

Modern TetraPak is very similar. It is made from a layer of plastic on the inside of the container, followed by aluminium foil, paperboard and an outer layer of plastic, and the layers are all bonded with polyethylene: paperboard provides strength, and can be easily printed on with high quality; the inner layer of plastic provides water resistance, making the package fully watertight, and protects the other layers; the foil protects against oxygen and light, to prevent the spoiling of the liquid inside.

Once the layers have been joined and the design printed, the roll of material is formed into a tube, which is sealed off into individual packages whilst being filled, in a very similar method to the original TetraPak. They are then sliced into individual packages, and assembled into their final shape. They are then shipped to the consumer.

By Oliver Gaskell | 2018 | olivergaskell.tk