WO2024105498A1

WO2024105498A1 - Hybrid turf

Info

Publication number: WO2024105498A1
Application number: PCT/IB2023/061259
Authority: WO
Inventors: Fabio TRAVAINI; Lorenzo TRAVAINI; Vincenzo Giovanni ALBINI
Original assignee: Biopolymer Swiss Ag
Priority date: 2022-11-18
Filing date: 2023-11-08
Publication date: 2024-05-23

Abstract

A hybrid turf (10) comprising a plurality of synthetic fibers (3) made of a biodegradable compound is described; wherein said biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) equal to or greater than 15% by weight and less than 60% by weight of the compound.

Description

HYBRID TURF

Field of the invention

The present invention relates to the field of turfs and in particular to a hybrid turf.

Known art

As known, hybrid turfs are portions of soil comprising natural (grass) and synthetic fibers, suitably interspersed, to obtain portions of lawn. The reinforcement imparted to natural fibers (natural grass) by synthetic fibers (artificial grass) ensures stability and a uniform playing surface immediately after installation.

The grass crown (heart) is then located between the artificial fibers covered with sand, where it is protected from wear and tear damage.

In some cases, synthetic turfs are constrained in an open-weave backing, clogged with specific sand.

In other cases, synthetic turfs do not provide backing elements and are directly "sewn" into the soil.

The Applicant has observed that whenever a new hybrid turf mat is to be installed at a site of use, the synthetic components of the old worn-out hybrid turf mat must be completely removed from the soil before the new hybrid turf can be installed. Removing the worn-out hybrid turf mat may not be easy, as the hybrid turf mat is often strongly interconnected with the roots of natural herbaceous plants. The disposal of the worn-out hybrid turf mat is challenging because the mixture of natural grass, dirt and synthetic materials, if undivided and not washed, cannot be recycled, is expensive to dispose of and, therefore, has a strong environmental impact.

The Applicant has therefore observed that an ever increasing number of producers of hybrid and artificial grass have begun to replace the conventional fibers and backing materials with biodegradable materials.

For example, the International Patent Application WO 2007/114686 describes the use of biodegradable synthetic fibers consisting of starch and polylactic acid (PLA).

The Applicant has however observed that the biodegradable fibers used to date do not allow a precise estimate of the biodegradability timings.

In fact, biodegradation is a process that depends on a plurality of environmental factors and on the actual life expectancy of an artificial or hybrid turf mat.

The Applicant has posed the problem of implementing a hybrid turf which is easy and economical to replace and dispose of and whose disposal does not result in a great environmental impact.

The Applicant has also posed the problem of implementing a hybrid turf which has precise biodegradability timings.

The Applicant has also posed the problem of the environmental impact of the current plastics used for this application, since they are in direct contact with the soil and aquifers.

Summary of the invention

Therefore, in its first aspect, the invention relates to a hybrid turf comprising a plurality of synthetic fibers made of a biodegradable compound, characterized in that said biodegradable compound comprises an amount of polybutylene succinate adipate PBSA equal to or greater than 15% and less than 60% by weight of the compound.

The present invention, in the aforementioned aspect, can have at least one of the preferred characteristics hereinafter described.

Preferably, the plurality of fibers are grouped into skeins, each comprising a plurality of filiform elements made of said biodegradable compound; said filiform elements being twisted for at least a length of their extent.

Conveniently, the hybrid turf comprises a backing element for the plurality of fibers.

Advantageously, the biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) equal to or greater than 15% and less than 60% by weight of the compound.

Preferably, the biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) equal to or greater than 40% and less than 60% by weight of the compound.

Conveniently, the biodegradable compound comprises an amount of poly-P- hydroxybutyrate (PHB)) equal to or less than 35% by weight to the total weight of the compound.

Preferably, the biodegradable compound comprises an amount of poly-P- hydroxybutyrate (PHB) equal to or greater than 25% by weight to the total weight of the compound.

Alternatively, the backing element comprises at least one first layer comprising a first net made of cotton or natural organic material comprising meshes defining a plurality of openings configured to allow natural grass to take root therein and in any case allow roots to pass through it.

Preferably, the backing element comprises a second layer combined with said first layer, said second layer comprising a net made of said biodegradable compound.

Conveniently, the first net includes meshes, each mesh being able to be inscribed in a square with side in the range from 0.2 cm to 2 cm.

Further characteristics and advantages of the invention will be more evident from the detailed description of some preferred, but not exclusive, embodiments of a hybrid turf according to the present invention.

Brief description of the drawings

Such description will be set forth hereunder with reference to the accompanying drawings provided by way of example only and thus not limiting, in which:

- Figure 1 shows a schematic perspective view of a first embodiment of the hybrid turf according to the present invention, with a partially exploded part;

- Figure 2 shows a schematic side view of a skein of filiform elements comprising synthetic fibers;

- Figure 3 shows a schematic perspective view of a second embodiment of the hybrid turf according to the present invention.

Detailed description of embodiments of the invention

With reference to the figures, a turf, preferably a hybrid turf according to the present invention, is denoted by the numerical reference 10.

In Figure 1 is shown that a first embodiment of the hybrid turf 10 according to the present invention comprises a backing element 2 and a plurality of synthetic fibers 3 combined with the backing element 2.

The hybrid turf 10 further comprises a plurality of grass blades 15 which are alternated with the synthetic fibers 3, so as to make a substantially continuous mat of grass blades 15 and synthetic fibers 3.

When installed, the backing element 2 may have a substantially planar configuration comprising at least one first layer 4 made of a first net 5 made of a natural organic material, preferably cotton.

Preferably, the first net 5 comprises meshes defining a plurality of openings configured so as to allow the natural grass blades 15 to take root inside it.

For this purpose, the first net 5 comprises meshes 8 being able to be inscribed in a square with side in the range between 0.1 cm and 2 cm.

In the embodiment shown in Figure 1, the backing element 2 also comprises a second layer 6 made of a second net 7 made of a biodegradable material.

Preferably, the biodegradable material making the second net 7 is the same as the synthetic fibers 3.

The second net 7 comprises meshes 9 defining a plurality of openings.

For this purpose, the second net 7 comprises meshes 9 being able to be inscribed, in plan view, in a square with side in the range from 0.2 cm to 2 cm.

In the embodiment shown in Figure 1, the first layer 4 is combined with the second layer 6.

Preferably, the first layer 4 is combined with the second layer 5 by hot-melt gluing.

Even more preferably, the first layer 4 is combined with the second layer 6 by a hot-lamination process.

In production, during the step of combining the first layer 4 with the second layer 6, there is substantial overlap between the meshes 8 of the first net 5 with the meshes 9 of the second net 7, so as to leave the openings adapted to allow the natural grass to cross the layers and take root thereunder.

In the embodiment shown in Figure 1, a plurality of synthetic fibers 3 made of a biodegradable compound, which is described in more detail below, are constrained to the backing element 2 constituted by the first 4 and second 6 layers combined together.

The synthetic fibers 3 are grouped into skeins 11, evenly distributed on the turf 10.

The synthetic fibers 3 are grouped into skeins 11 evenly distributed on the hybrid turf 10, so as to form a fiber density per m² (square meter) in the range between 45000 fibers/m² and 80000 fibers/m².

Each skein 11, better shown in Figure 2, comprises a plurality of filiform elements 12 made of a biodegradable compound described in more detail below.

The synthetic fibers 3 are thus depicted by the filiform elements 12.

Each skein 11 comprises a number of filiform elements 12 or synthetic fibers 3 ranging from five to fifteen, preferably from six to twelve.

In each skein 11, the filiform elements 12 have the same extent ranging from 2 to 20 cm, including extremes.

In each skein 11, the filiform elements 12 are twisted together for at least a length T of their extent.

Preferably, in every skein 11, the filiform elements 12 are twisted together for at least 1/3 of their extent.

Preferably, in every skein 11, the filiform elements 12 are twisted together for at least 2/3 of their extent.

In the embodiment shown in figure 1, the skeins 11, suitably folded on themselves preferably so as to form a “V”, are combined with the backing element 2 by means of sewing.

Preferably, in the embodiment shown in figure 1, the skeins 11, suitably folded on themselves preferably so as to form a “V”, are combined with the backing element 2 by means of a sewing process referred to as “tufting”.

As previously mentioned, the synthetic fibers 3 are made of a biodegradable material.

Preferably, the synthetic fibers 3 are made of a biodegradable compound comprising an amount of polybutylene succinate adipate (PBSA) equal to or greater than 15% by weight and less than 60% by weight to the total weight of the compound, the value of 60% by weight being excluded.

According to a first embodiment, the biodegradable compound comprises at least 30% by weight to the total weight of the compound of polybutylene succinate adipate (PBSA) and a maximum of 60% by weight to the total weight of the compound of polybutylene succinate adipate (PBSA), the value of 60% by weight being excluded.

Preferably, the biodegradable compound comprises at least 40% by weight to the total weight of the compound of polybutylene succinate adipate (PBSA) and a maximum of 60% by weight to the total weight of the compound of polybutylene succinate adipate (PBSA), the value of 60% by weight being excluded.

Even more preferably, the biodegradable compound comprises at least 45% by weight to the total weight of the compound of polybutylene succinate adipate (PBSA) and a maximum of 60% by weight to the total weight of the compound of polybutylene succinate adipate (PBSA), the value of 60% by weight being excluded.

According to another embodiment, the biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) between 45% and 55% by weight to the total weight of the compound. Preferably, according to this embodiment, the biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) between 50% and 55% by weight to the total weight of the compound. Still according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or less than 25% by weight to the total weight of the compound.

Preferably, according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or greater than 5% by weight to the total weight of the compound.

Preferably, according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or less than 20% by weight to the total weight of the compound.

Even more preferably, according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or greater than 10% by weight to the total weight of the compound. According to yet another embodiment, the biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) between 45% and 55% by weight to the total weight of the compound. Preferably, according to this embodiment, the biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) between 50% and 55% by weight to the total weight of the compound. Still according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or less than 40% by weight to the total weight of the compound.

Preferably, according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or greater than 20% by weight to the total weight of the compound.

Preferably, according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or less than 35% by weight to the total weight of the compound.

Even more preferably, according to this embodiment, the biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or greater than 25% by weight to the total weight of the compound.

When the hybrid turf is planted on already prepared soil, it is filled with sand 14 so that the latter has a depth of at least 10 cm relative to the backing element 2, preferably a depth of at most 30 cm relative to the backing element 2.

Sands 14 suitable for the purpose are silica sands of various grain sizes, preferably USGA certified.

Once filled with sand 14, the hybrid turf 10 is sown so that the grass blades 15 can take root and develop between a skein 11 and the next one.

As the roots of the grass blades 15 grow, they pass through the meshes of the backing element 2, thus constraining the hybrid turf 10 to the underlying soil.

An alternative embodiment of the hybrid turf 10 according to the present invention is shown in Figure 3. In particular, the hybrid turf 10 of figure 3 is completely similar to the hybrid turf of figure 1, except that it does not have any backing element 2 and that the skeins 11 can have a larger dimension. According to this embodiment, the skeins 11, suitably folded on themselves preferably so as to form a “V”, are not combined with the backing element 2 (which is not present) but with the soil through suitable “sewing” machines.

This hybrid turf, as evident from the above description, has the following advantages:

- it allows to reduce the environmental impact of the disposal compared to conventional hybrid turfs;

- it allows to reduce or eliminate disposal costs;

- construction simplicity combined with high reliability; - precise timings of biodegradability.

Several changes can be made to the embodiments described in detail, all anyhow remaining within the scope of protection of the invention as defined by the following claims.

Claims

1. Hybrid turf (10) comprising a plurality of synthetic fibers (3) made of a biodegradable compound; characterized in that said biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) equal to or greater than 15% and less than 60% by weight of the compound.

2. Hybrid turf (10) according to claim 1, characterized in that said plurality of synthetic fibers (3) are grouped into skeins (11), each comprising a plurality of filiform elements (12) made of said biodegradable compound.

3. Hybrid turf (10) according to claim 1 or 2, characterized in that it comprises a backing element (2) for said plurality of synthetic fibers (3).

4. Hybrid turf (10) according to claim 3, characterized in that said biodegradable compound comprises an amount of polybutylene succinate adipate (PBSA) equal to or greater than 30% and less than 60% by weight of the compound.

5. Hybrid turf (10) according to any one of claims 1 to 4, characterized in that said biodegradable compound comprises an amount of polybutylene succinate adipate equal to or greater than 40% and less than 60% by weight of the compound.

6. Hybrid turf (10) according to any one of claims 1 to 5, characterized in that said biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or less than 35% by weight to the total weight of the compound.

7. Hybrid turf (10) according to claim 6, characterized in that said biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal or greater than 25% by weight to the total weight of the compound.

8. Hybrid turf (10) according to claim 6, characterized in that said biodegradable compound comprises an amount of poly-P-hydroxybutyrate (PHB) equal to or less than 25% and equal to or greater than 5% by weight to the total weight of the compound.

9. Hybrid turf (10) according to any one of claims 1 to 7, characterized in that said backing element comprises at least one first layer (4) comprising a first net (5) made of natural organic material comprising meshes defining a plurality of openings configured to allow natural grass to take root therein.

10. Hybrid turf (10) according to claim 4, characterized in that said backing element (2) comprises a second layer (6) combined with said first layer (4), said second layer (6) comprises a net (7) made of said biodegradable compound.

11. Hybrid turf (10) according to claim 9, characterized in that said first net (5) comprises meshes, each mesh being able to be inscribed in a square with side in the range from 0.2 cm to 2 cm.

12. Hybrid turf (10) according to any one of claims 1 to 11, comprising a plurality of grass blades (15) interspersed with said plurality of synthetic fibers (3).