Stefan Sodenborg, a Swedish farmer and machinery engineer with extensive experience in traditional baling machinery has pioneered and patented the cross-pack wrapping technique. Here an additional layer of film is fed through the pre-stretch machine and then cross-wrapped at 90-degree angles to the conventional layers.
According to the engineer, a number of distinct benefits are achieved. First, it provides tension in the bale across all three dimensions — meaning that the bale ‘package’ has a much more consistent strength and rigidity. This allows stacking bales far higher, as the bales keep their shape better. Secondly, the crossed layers do not bind together with the conventional layers at the contact surfaces, as occurs when the wrapping is all in one direction. This allows a limited amount of movement between the two crossed layers, which provides additional protection against damage during storage and transportation as there is a reduced tendency for the film to tear if the bale is stressed in one direction.
The cross-pack technique also provides a strong oxygen barrier — keeping bales ‘fresh’ for up to five years – much longer than is commonly possible with conventional wrapping.
Studies have also shown that there are significant cost savings to be made by using the cross-pack wrapping technique as less film is required to wrap a bale effectively. For example, a conventional 1.5 m bale wrapped with 16 layers of film uses around 4.5kg of wrap — 70% pre-stretched film. The cross-pack method will use only about 2kg of film for the same 1.5 m bale wrapped with 16 layers — 120 – 160% pre-stretched.