Artificial grass is commonly used, for instance, on football, baseball and land hockey pitches, but can be seen more and more also on golf and tennis courts and in other places such as gardens, terraces and patios. Artificial grass is advantageous since, contrary to natural grass, it does not require watering in summer and does not freeze in winter. Moreover, artificial grass does not need fertilizing, mowing or airing.
Artificial turf consists, for example, of a combination of a mat of filaments and an infill material. The infill material can be, for example, different combinations of sand, crushed rubber (e.g. ground tires) and plastic granules.
To install the artificial turf, strips of the mat are rolled out on a base, such as a field or pitch. The strips of mat are glued together using, for instance, adhesive strips which are disposed underneath the strips. After the mats have been rolled out and glued together the infill material is distributed across the mat. If a mat with divisible grass filaments is used, such as a “split-fibre mat”, the grass is brushed in such a manner that the grass filaments are split. If a “monosplit mat” is used, a filament can be split into, for example, 1-7 filaments, and if a “full split mat” is used a filament can be split into, for example, 8-15 filaments.
For football field grass, in particular artificial grass, to be used on fields intended for international games it must meet certain quality requirements and must satisfy the standards imposed by, for instance, FIFA (Federation Internationale de Football Association) and UEFA (Union of European Football Associations). When the artificial turf is worn out and no longer meets these requirements, which may be the case already after a year, it must be replaced by a new artificial turf. Another reason for removing the artificial turf may be that the field needs to be relocated because the land is to be used for other purposes, for example for a housing project. Yet another reason may be that the artificial turf has been installed in an inappropriate location where, for example, ground drainage is poor.
Since artificial turfs represent a considerable investment, it is desirable to be able to reuse artificial turf which, for instance, does not meet the requirements for international events, but which might be used in other contexts. In certain cases, the infill material too can be reused. Even if the infill material is not reused, it is still desirable to separate it from the artificial turf in order to save the costs for the controlled dumping of the infill material.
There are many problems associated with the removal of artificial turf. Typically, the infill material is distributed in such a manner that the weight distribution is approximately 30 kg/m2. One roll of artificial grass, i.e. one strip of turf, can weigh approximately one metric ton and the infill material that is distributed over a strip of turf can weigh approximately ten metric tons.
Thus, one way of removing the turf would be to cut it into smaller pieces, which are easier to handle. A problem with this solution, however, is that it is very difficult to put these little pieces back together again, which complicates the reuse of these pieces to form a new artificial turf.
Another way of making the artificial turf lighter is to remove the infill material at an initial stage by means of, for example, an apparatus similar to the sweeping vehicles that are used for sweeping the streets. A drawback of this solution, however, is that the infill material whirls up into the air when brushed off, which may cause it to spread through the air and settle in the stands necessitating cleaning of the stands; it may also inconvenience the staff carrying out the sweeping. A further drawback of this solution is that it is not possible to remove all of the infill material from the mat and if the sweeping vehicle makes several runs across the artificial turf the filaments will be damaged, which will make further reuse of the artificial turf impossible.
Consequently, the removal of artificial turf is highly problematic and the lack of satisfactory solutions is evident.