BioPitch – Swedish forest on football pitches

A new infill is necessary

It is most probable that EU will demand that the current infill material is replaced with biobased alternatives that not release microplastics. Even cork and other biomaterials usually have a plastic component and does not meet all requirements. Football clubs and municipalities that are responsible for fields often have high demands on sustainability.

It is possible to use treetops and branches from Swedish forests that today goes to incineration. Sweden is also in the forefront of exploiting lignin, the glue that merges the fibres in the tree and enables it to become tall. Within PioPitch a lignin formula has been developed to bind the wood fibre material into granules. The third ingredient is a biobased polymer that besides being biobased, also will be degradable.

The aim is to provide football clubs and municipalities with an infill that is 100 % biobased and degrades if it is dispersed in nature. When the turf reach end of life, the infill can be reused on the new mat or degraded and brought back to nature.

How come the number of artificial turfs in the world is growing?

The major reason is playing time.

• Natural grass: allows 200-400 hours of playing time annually, depending on weather and maintenance.
• Hybrid field: fields with natural grass empowered with artificial turf are playable 2-3 times more.
• Artificial field: playable 2,000-2,500 hours.

There are surveys indicating that the number of artificial turfs will double in the next 10 years.

A full size 11-a-side field is usually layered with 15 mm infill. That is 102 m³ or 67 metric tonnes.

 Today (2020) there are about 21,000 full size football pitches in Europe and 70 000 smaller ones. That corresponds to 1.9 million tonnes of today’s common infill. There are no reliable statistics of the whole world but there are assumptions that it is the same amount in the remaining world, with an increasing interest in Asia. 

Why is infill needed and what defines a performance infill?

Performance for players

• The artificial straws do not give in the way natural grass does, the shoes don’t glide as well with risk of rotational injuries occurring in ankle and knee.
• In rain the turf instead becomes very slippery, but a good infill reduces the effect.
• When gliding the friction create burns on the bare skin without infill.
• With infill the ball roll and bounce behaviour become more equal to the conditions a natural grass field.
• Without infill the artificial grass pitch is harder and there is a risk of hitting the heel, knee or hip.

Performance with turf systems

The performance of the infill depends on circumstances beyond the material itself.     

Thickness and softness of the shock pad under the turf is balanced with the amount of sand and infill. The infill needs to be designed to suit a variety of straw length/thickness/softness of a number of manufacturers.

Performance in all weather for long time

The infill should stay cool when the sun is shining, it may not float away in rain or blow away in wind. Nor may it clog in snow. It should not stick to clothes or shoes. It should be easy to maintain at top level performance, easily uncompressed if compacted.  

What steps are included in the project?

Here is an overview, for a more detailed information there is contact information below.

The earlier research project BioPitch step 1 proved that a material made in a lab have the properties needed. In the current step 2 the formula is adapted to cope with production volumes going from a kilo or two, to several tonnes for full scale tests on a football pitch.

When the project is finished there will be an infill available that has passed FIFA tests, is liked by players and pitch owners. Industrial scale production has been tried out in pilot scale.