Strength and porosity – the natural properties of paper sacks offer considerable efficiency advantages, resulting in lower total costs, as well as smoother and quicker processes when compared to alternative sack packaging.
More strength with less material
Thanks to our continuous performance improvements, the material efficiency of paper sacks has been greatly enhanced in recent years:
- The paper requirement per sack has been reduced by 25% over the past two decades, resulting in considerable reductions in costs and natural resources.
- The strength of sack kraft paper has been optimised by 45% over the same period. Today, just 100 g of paper can hold up to 25 kg of filling material. Hardly any other packaging product can achieve this level of efficiency.
Porosity provides process- and cost-efficiency …
The natural porosity of sack kraft paper is the second reason why paper sacks are extremely efficient. Acting as a filter material, it enables the air used in the filling process for dry bulk goods to escape very quickly. This allows filling speeds that are three times higher than those of non-paper sacks which are not porous. At present, paper sacks are the most efficient packaging solution regarding filling capacity. Moreover, the machinery needed to fill non-paper sacks is much more complex than for paper sacks: extra systems are needed to extract the air that cannot escape through the material during the filling process. The investment required is four to five times higher than for paper-sack-filling machines as a result. Thanks to the uncomplicated construction of a paper-sack-filling machine, the machine set-up when changing sacks is quick:
- High-porosity paper enables rapid, problem-free venting during filling, without the need for complex and costly air extraction systems. The porosity of sack kraft paper has risen by almost 30% in the last two decades.
- This makes it possible to achieve filling speeds of 3.5 seconds for a 25 kg paper sack.
… and benefits during transport and storage
Porosity also has efficiency benefits during transport and storage. As the air escapes easily from paper packaging, palletisation is typically easier and more efficient than for non-paper sacks. This results in lower heights for the same tonnage, making it possible to achieve greater loads on containers and trucks.