Reticular structure, turf and process for the realization of turfs

Abstract

The present invention relates to a reticular structure comprising: first and second elements spaced from each other and having an elongated conformation which intersect at nodes to form meshes; the reticular structure (2) is made of material comprising: a polymeric composition, a degradation additive configured to promote, in use, the degradation of the reticular structure (2).

Description

[0001] RETICULAR STRUCTURE, TURF AND PROCESS FOR THE REALIZATION OF TURFS

[0002] DESCRIPTION FIELD OF THE INVENTION

[0003] The present invention has as its object a reticular structure usable for land consolidation and / or stabilization. For example, the reticular structure object of the present invention can be used for the realization and the consolidation of turfs, for example grass sods, rolls and turfs. In particular, the reticular structure can be used for the realization of turfs of sports fields (soccer fields, golf courses, etc.), road funds and parking areas. The present invention concerns also a process for the realization of said reticular structure as well as a process for the realization of turfs.

[0004] STATE OF THE ART

[0005] There are known nets made of plastic material used for reinforcing, containing, and / or consolidating land. In particular, nets made with high-density polymers are widely used in the geotechnical sector starting from a semi-finished product consisting of a uni-planar extruded sheet and subsequently holed which is then submitted to a step of stretching; this process allows to realize the so-called single-oriented or doubleoriented nets as described in the following patent applications: US5419659A, US2004062615A1 , US3386876, US7407699B2, US6423394B1.

[0006] Alternatively, the known nets can be realized by extruding a monolithic reticular structure subsequently stretched along one or more directions to define a single-stretch or double-stretch net. These nets are, for example, described in the patent applications US4662946A, US5753337A and US4190692A.

[0007] The above-mentioned nets result chemically inert and have an excellent tensile strength in the direction of the stretched elements: the nets are capable of absorbing the stresses and redistributing them evenly in the soil thereby, ultimately, ensuring a greater static and dynamic strength of the entire reinforced structure. However, although the above-mentioned nets are widely used, the Applicant has noted that such known nets are not free from limitations. These nets are configured to maintain their chemical nature unchanged over time and thus not to be absorbed by the land with consequent negative environmental impact: such materials are in fact considered pollutants. Further than defining a product polluting for the environment, the above-mentioned known nets have limitations for some uses, as for example the realization of sods or grass rolls for ready-to-lay turfs. The non-biodegradability of the nets may cause the permanence of portions of the netitself that emerge from the sod hindering the periodic turf cutting and the subsequent collecting step, causing inconveniences to turf mowing machinery.

[0008] Land consolidation nets made of biodegradable material capable of providing land consolidation for a predetermined period of time before changing its chemical nature and being absorbed by the land were therefore developed. In particular, are known biodegradable consolidation nets made of polylactic acid (PLA), polybutylene succinate (PBS) and polylactic acid (PLA) mixtures. For example, in the PCT patent application n. WO 2020 / 252233 A1 have been described nets of biodegradable material made by means of a mixture of PBS, PLA and a degrading additive; these nets are used for grass sod cultivation. Additional additivated nets of biodegradable material are described in the patent application n. WO 2022 / 243798 A1.

[0009] Although the biodegradable nets are nowadays used for the consolidation and the realization of grass sods, the Applicant has noted that they have several drawbacks and are therefore improvable in several aspects. The biodegradable nets are in fact difficult to process and require the addition of expensive additives designed to promote the processability of the net and / or expedients in the production process that make such nets quite expensive.

[0010] The patent application n. WO 2010 / 056822 describes instead a double-oriented net of non-degradable material, additivated with oxodegrading agents to allow fragmentation into intermediate microplastics over time. In detail, the degradation additive is configured to initiate an abiotic degradation of the material, for example by exposure to UV light, oxygen or heat, with the formation of progressively reduced polymer fragments. However it is useful to note that the net, as a result of use, produces persistent microplastics polluting for the environment.

[0011] The Applicant has noted the presence of major limitations in the solutions known today, which are therefore improvable in several respects.

[0012] OBJECT OF THE INVENTION

[0013] A purpose of the present invention is therefore to substantially solve at least one of the drawbacks and / or limitations of the preceding solutions.

[0014] A first objective of the present invention is to make available a reticular structure having a high mechanic strength which can thus correctly consolidate the land but at the same time result biodegradable; in particular, it is an objective of the present invention to make available a reticular structure that can effectively consolidate the land for a predetermined period of time and that can correctly degrade after said period in such a way as to result biodegradable.

[0015] A further object is to make available a reticular structure that can effectively couple with a turf to facilitate its transport and subsequent laying.An additional object is to make available a reticular structure that can be arranged on a land and allow the cultivation of grass by coupling with the root apparatus of the turf to facilitate its separation from the growing medium, transport, and subsequent laying in a target land.

[0016] It is then an object of the present invention to make available a reticular structure easily and properly processable, also by a realization process of extrusion using a pulsating type head. In particular, it is an object of the present invention to make available a reticular structure realizable with low production costs. These objects and others, which will appear more from the following description, are substantially achieved by a reticular structure, a process for the realization thereof and a process for the realization of turfs according to one or more of the attached claims and / or of the following aspects.

[0017] SUMMARY

[0018] In a 1st aspect is provided a monolithic reticular structure (2), said reticular structure (2) comprising: a plurality of first elements (3) spaced from each other and having an elongated conformation according to a first development trajectory (T1),

[0019] a plurality of second elements (4) spaced from each other and having an elongated conformation according to a second development trajectory (T2) transverse, optionally orthogonal, to the first development trajectory (T1) of the first elements (3),

[0020] wherein said first and second elements (3, 4) intersect at nodes (5) to form meshes (6).

[0021] In a 2nd aspect according to the preceding aspect the reticular structure (2) is used for carrying out at least one of: the consolidation of the land, the reinforcement of the land, the realization of turfs.

[0022] In a 3rd aspect according to any one of the preceding aspects the reticular structure (2) is made at least partly of polymeric, non-degrading, optionally non-biodegradable material. In a 4th aspect according to any one of the preceding aspects the reticular structure (2) is realized (optionally entirely) in material comprising: a polymeric composition, a degradation additive configured to promote, in use, the degradation of the reticular structure (2).

[0023] In a 5th aspect according to the preceding aspect the polymeric composition is in weight percentage more than 80% with respect to the total weight of the material of the reticular structure (2), optionally between 85% and 99% with respect to the total weight of the material of the reticular structure (2), even more optionally between 90% and 98% with respect to the total weight of the material of the reticular structure (2), for example between 92% and 97% with respect to the total weight of the material of the reticular structure (2).

[0024] In a 6th aspect according to any one of the two preceding aspects the polymeric composition comprises polyolefin. In a 7th aspect according to any one of the three preceding aspects the polymeric composition is of the thermoplastic type. In an 8th aspect according to any one of the four preceding aspects the polymericcomposition comprises at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / a-olefin copolymers, combinations thereof. In a 9th aspect according to any one of the five preceding aspects the polymeric composition is constituted only by at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / a-olefin copolymers, combinations thereof. In a 10th aspect according to any one of the six preceding aspects the polymeric composition comprises at least one of the following materials: polyethylene, polypropylene. In an 11th aspect according to any one of the seven preceding aspects the polymeric composition is constituted by polyethylene. In a 12th aspect according to any one of the eight preceding aspects the polymeric composition is constituted by polypropylene.

[0025] In a 13th aspect according to any one of the preceding aspects from 4th to 12th the reticular structure (2) material comprises a percentage by weight of degradation additive between 1.5% and 15%, optionally between 2% and 10%, even more optionally between 3% and 8%, with respect to the total weight of said material. In a 14th aspect according to any one of the preceding aspects from 4th to 13th the degradation additive comprises at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose. In a 15th aspect according to any one of the preceding aspects from 4th to 14th the degradation additive is configured, in conditions of use of the reticular structure, to generate at least an enzymatic process to allow the scission of the polymeric material of the reticular structure. In a 16th aspect according to any one of the preceding aspects from 4th to 15th the degradation additive is configured to degrade the reticular structure (2) by means of enzyme-driven microbial action, optionally to promote carbon-carbon bond breaking. In a 17th aspect according to any one of the preceding aspects from 4th to 16th the degradation additive is configured to completely degrade the reticular structure by means of microorganisms in at least one of: water, carbon dioxide, biomass. In an 18th aspect according to any one of the preceding aspects from 4th to 17th the degradation additive, after the degradation action of the reticular structure (2), is configured to prevent the formation of plastic residues.

[0026] In a 19th aspect according to any one of the preceding aspects from 4th to 18th the reticular structure (2) material comprising:

[0027] polyolefin by weight between 90% and 98% with respect to the total weight of the reticular structure (2) material,

[0028] the degradation additive by weight between 2% and 10% with respect to the total weight of the reticular structure (2) material.

[0029] In a 20th aspect according to the preceding aspect the degradation additive comprises at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose. In a 21st aspect according to anyone of the two preceding aspects the polyolefin comprises at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof.

[0030] In a 22nd aspect according to any one of the preceding aspects from 4th to 21st the reticular structure (2) material can comprise one or more additives, optionally comprising at least one of: a compatibilizing additive, a filler additive.

[0031] In a 23rd aspect according to the preceding aspect the compatibilizing additive is configured to increase at least one of the adhesion, the mixability or the cohesion between polymeric components of different nature. In a 24th aspect according to the preceding aspect the compatibilizing additive is polymer-based. In a 25th aspect according to any one of the two preceding aspects the reticular structure (2) material comprises a quantity of compatibilizing additive between 0,1% and 2% with respect to the total weight of the reticular structure (2) material. In a 26th aspect according to any one of the three preceding aspects the compatibilizing additive comprises at least one of the following materials: polypropylene grafted with maleic anhydride, polyethylene grafted with maleic anhydride, ethylene-vinyl acetate, styrene-ethylene-butylene-styrene grafted with maleic anhydride. In a 27th aspect according to any one of the four preceding aspects the material can comprise a compatibilizing additive chosen among copolymers grafted with maleic anhydride, as PP-g-MAH, PE-g-MAH or SEBS-g-MAH, or an ethylene-vinyl acetate copolymer with high content of VA (high EVA VA) suitable for improving the compatibility between the olefin matrix and polar or degradable components.

[0032] In a 28th aspect according to any one of the aspects from 22nd to 27th the filler additive is configured to change the physical-mechanical properties of the reticular structure (2) material. In a 29th aspect according to any one of the aspects from 22nd to 28th the reticular structure (2) material comprises a quantity of filler additive between 0,5% and 10% with respect to the total weight of the reticular structure (2) material. In a 30th aspect according to any one of the aspects from 22nd to 29th the filler additive comprises at least one of: industrial agricultural waste, wood processing waste, materials composed of natural polymers. In a 31st aspect according to any one of the aspects from 22nd to 30th the filler additive comprises at least one of: cellulose, corn starch, natural rubber, linseed oil, wheat glume, wood flour, quill keratin hydrolysate, sodium lignosulfonate, seed shells, birch leaves or the like, hay, fruit waste, date palm wood, cellulose, hemicellulose and lignin.

[0033] In a 32nd aspect according to any one of the preceding aspects the first elements (3) are parallel to each other, optionally the development trajectories (T1) of the first elements (3) are parallel to each other. In a 33rd aspect according to any one of the preceding aspects the trajectories (T1) of the first elements (3) are rectilinear.In a 34th aspect according to any one of the preceding aspects the first elements (3) are stretched along their development. In a 35th aspect according to the preceding aspect the first elements (3) have a stretching ratio greater than 1,5, optionally between 2 and 8, more optionally between 2,5 and 4. In a 36th aspect according to the preceding aspect the stretching ratio of the first elements (3) is defined as the ratio between a final length of the first elements after a stretching action of them and an initial length of the first elements before stretching.

[0034] In a 37th aspect according to any one of the preceding aspects the first elements (3) have a substantially threadlike structure. In a 38th aspect according to any one of the preceding aspects said first elements (3) have a transversal section, measured at a centerline portion defined between two immediately consecutive nodes, of area less than 5 mm2, optionally between 0,1 mm2and 1,5 mm2. In a 39th aspect according to any one of the preceding aspects the first elements (3) have a full cross section. In a 40th aspect according to any one of the preceding aspects the tract of a first element (3) between two consecutive nodes (5) has, for at least 80% of the total extent of said tract, a change in terms of area section of less than 20%, optionally less than 15%, even more optionally less than 10%.

[0035] In a 41st aspect according to any one of the preceding aspects the second elements (4) are parallel to each other. In a 42nd aspect according to any one of the preceding aspects the second development trajectories (T2) of the second elements are parallel to each other. In a 43rd aspect according to any one of the preceding aspects the trajectories (T2) of the second elements (4) are rectilinear.

[0036] In a 44th aspect according to any one of the preceding aspects the second elements (4) are stretched along their development. In a 45th aspect according to the preceding aspect the second elements (4) have a stretching ratio greater than 1,5, optionally between 2 and 5, more optionally between 2 and 4, wherein the stretching ratio of the second elements (4) is defined as the ratio between a final length of the second elements after a stretching action of them and an initial length of the second elements before stretching. In a 46th aspect according to any one of the preceding aspects the second elements (4) have a substantially threadlike structure. In a 47th aspect according to any one of the preceding aspects the second elements (4) have a cross section, measured at a centerline portion defined between two immediately consecutive nodes, of area less than 5 mm2, optionally between 0,1 mm2and 1.5 mm2. In a 48th aspect according to any one of the preceding aspects the second elements (4) have a full cross section. In a 49th aspect according to any one of the preceding aspects the tract of a second element (4) between two consecutive nodes (5) has, for at least 80% of the total extent of said tract, a change in terms of area section of less than 20%, optionally less than 15%, even more optionally less than 10%.

[0037] In a 50th aspect according to any one of the preceding aspects the ratio between the distance between the two adjacent first elements and the distance between two adjacent second elements is between 0,5 and 2,optionally between 0,8 and 1.2. In a 51st aspect according to any one of the preceding aspects two first elements immediately adjacent with respect to a direction orthogonal to the development trajectory of at least one of said adjacent first elements are placed at a minimum distance the one with respect to the other between 5 mm and 70 mm, optionally 10 mm and 25 mm. In a 52nd aspect according to any one of the preceding aspects each first element (3) has a tract that connects two immediately consecutive nodes (5), wherein said tract has a surface-to-volume ratio greater than 5 mm1, optionally 10 mm1, wherein said surface-to-volume ratio is defined as the ratio between the area of the external surface of said tract and the volume of the same tract.

[0038] In a 53rd aspect according to any one of the preceding aspects two second elements immediately adjacent with respect to a direction orthogonal to the development trajectory of at least one of said adjacent second elements are placed at a minimum distance the one with respect to the other between 5 mm and 70 mm, optionally 12 mm and 45 mm. In a 54th aspect according to any one of the preceding aspects each second element (4) has a tract that connects two immediately consecutive nodes (5), wherein said tract has a surface-to-volume ratio greater than 5 mm1, optionally 10 mm1, wherein said surface-to-volume ratio is defined as the ratio between the area of the external surface of said tract and the volume of the same tract. In a 55th aspect according to any one of the preceding aspects the first elements (3) are substantially identical to the second elements (4). In a 56th aspect according to any one of the preceding aspects the first elements (3) are identical in form to the second elements (4). In a 57th aspect according to any one of the preceding aspects the first elements (3) are identical in size to the second elements (4).

[0039] In a 58th aspect according to any one of the preceding aspects the reticular structure (2) comprises meshes having a quadrilateral shape, optionally having square or rectangular shape. In a 59th aspect according to any one of the preceding aspects the reticular structure (2) has an areal mass ranging between 3 g / m2and 30 g / m2, optionally between 5 g / m2and 15 g / m2.

[0040] In a 60th aspect according to any one of the preceding aspects the ratio between an area of a cross section of a first element (3), measured at an intermediate portion between two immediately consecutive nodes (5), and an area of a cross section of a second element (4), measured too at an intermediate portion between two immediately consecutive nodes (5), is between 0,5 and 2, optionally between 0,7 and 1,2.

[0041] In a 61st aspect according to any one of the preceding aspects the reticular structure (2) has a specific tensile resistance, along the development path of the first and / or second elements (3, 4) equal to or greater than 0,5 kN / m, in particular between 0,7 kN / m and 10 kN / m, optionally between 0,7 kN / m and 3 kN / m; said specific tensile resistance being measured with the method given in ASTM D7179.

[0042] In a 62nd aspect according to any one of the preceding aspects the first and second elements (3, 4) are obtained by stretching a semi-finished product with a reticular structure having first and second precursorelements intersecting at nodes to define meshes. In a 63rd aspect according to the preceding aspect the semi-finished product with a reticular structure is obtained through:

[0043] an extrusion process, or

[0044] extrusion of a solid sheet subsequently cut.

[0045] In a 64th aspect according to any one of the two preceding aspects the semi-finished product with a reticular structure is obtained through an extrusion process with pulsating technology. In a 65th aspect according to any one of the preceding aspects the reticular structure (2) is realized through an extrusion process with pulsating technology.

[0046] In a 66th further aspect it is provided a process for the realization of a reticular structure (2) in accordance with any one of the preceding aspects. In a 67th aspect according to the preceding aspect the process comprises a step of extrusion of biodegradable material to form the reticular structure (2) having said first and second elements (3, 4) of elongated shape and extending along respective transversal development trajectories, optionally orthogonal, the one with respect to the other, the first and second elements (3, 4) intersecting at nodes (5) to form meshes (6).

[0047] In a 68th aspect according to the two preceding aspects the process comprises the sub-steps of: extruding a monolithic semi-finished product with a reticular structure having first and second precursor bodies of elongated shape and extending along respective transversal development trajectories, optionally orthogonal, the one with respect to the other, the first and second precursor bodies intersecting at nodes to form meshes,

[0048] stretching the semi-finished product along the development of the first and / or second precursor bodies so as to define a stretched reticular structure (2) defined by said first and second elements (3, 4).

[0049] In a 69th aspect according to the preceding aspect the process comprises a step of stretching the semifinished product along the development of the first and second precursor bodies so as to define said reticular structure (2) having said first and second elements (3, 4) stretched along their development, optionally to define a double-stretch reticular structure (2). In a 70th aspect according to any one of the preceding aspects of the process the step of stretching is carried out along the development of the first and second precursor bodies to define a double-stretch reticular structure.

[0050] In a 71st aspect according to any one of the preceding aspects of the process the semi-finished product is obtained continuously by means of a process of extrusion, optionally by means of pulsating technology. In a 72nd aspect according to any one of the preceding aspects of the process the step of extrusion comprises the following sub-steps:extruding said monolithic semi-finished product with a reticular structure in cylindrical form wherein the first precursor bodies extend along an extrusion direction while the second precursor bodies, each of which has substantially circular shape, extend transversally, optionally orthogonally, to the first precursor bodies, moving said monolithic semi-finished product along an advancement direction (MD),

[0051] cooling said monolithic semi-finished product,

[0052] cutting said monolithic semi-finished product having circular shape advancing along the advancement direction (MD) so that the semi-finished product itself can open and subsequently spread in a flat form wherein said first precursor bodies extend parallel to the advancement direction (MD) while said second precursor bodies extend transversally, optionally orthogonally, to said advancement direction (MD).

[0053] In a 73rd aspect according to the preceding aspect the extrusion of the monolithic semi-finished product with a reticular structure is carried out by means of a cylindrical extrusion head with pulsating technology. In a 74th aspect according to any one of the preceding aspects of the process the monolithic semi-finished product with reticular structure, open and spread in flat form, has said first and second precursor bodies lying essentially on a same plane.

[0054] In a 75th aspect according to any one of the two preceding aspects the step of stretching is carried out on the monolithic semi-finished product with reticular structure after the step of cutting and spreading thereof. In a 76th aspect according to any one of the three preceding aspects the step of stretching is carried out on the monolithic semi-finished product with reticular structure when laid flat along at least a stretching direction. In a 77th aspect according to any one of the three preceding aspects the step of stretching is carried out on the monolithic semi-finished product with reticular structure when laid flat along at least one stretching direction.

[0055] In a 78th aspect according to any one of the preceding aspects from 69th to 77th, the step of stretching of the monolithic semi-finished product with reticular structure is carried out along at least one of the following directions:

[0056] a stretching direction substantially parallel to the advancement direction (MD), optionally parallel to the development trajectory of the first precursor bodies,

[0057] a stretching direction substantially orthogonal to the advancement direction (MD), optionally parallel to the development trajectory of the second precursor bodies.

[0058] In a 79th aspect according to any one of the preceding aspects from 69th to 78th, the step of stretching of the monolithic semi-finished product with reticular structure is carried out along the development trajectories of the first and second precursor bodies to define a reticular structure (2) with first and second elements (3, 4) stretched along their development.In a 80th aspect according to any one of the preceding aspects from 69th to 79th the stretching ratio of each first element (3) is defined as the ratio between a final length of the same first element once the stretching is carried out and the initial length of such first element before the stretching action, i.e. the length of the first precursor body capable of defining said first element (3). In a 81st aspect according to any one of the preceding aspects from 69th to 80th the first elements (3) have a stretching ratio greater than 1,5, optionally between 2 and 8, more optionally between 2,5 and 4, the stretching ratio of the first elements (3) is defined as the ratio between a final length of the first elements after a stretching action of them and an initial length of the first elements before stretching.

[0059] In a 82nd aspect according to any one of the preceding aspects from 69th to 81st the stretching ratio of each second element (4) is defined as the ratio between a final length of the same second element once the stretching is carried out and the initial length of such second element before the stretching action, i.e. the length of the second precursor body capable of defining said second element (4). In a 83rd aspect according to any one of the preceding aspects from 69th to 82nd the second elements (4) have a stretching ratio greater than 1,5, optionally between 2 and 5, more optionally between 2 and 4, the stretching ratio of the second elements (4) is defined as the ratio between a final length of the second elements after a stretching action of them and an initial length of the second elements before stretching.

[0060] In an 84th aspect according to any one of the preceding aspects the material used in the process for the realization is in accordance with the material according to any one of the preceding aspects from 1 to 65. In an 85th aspect according to any one of the preceding aspects from 68th to 84th, the step of extrusion is carried out at a temperature between 110 °C and 180 °C, optionally between 150 °C and 175°C.

[0061] In an 86th aspect according to any one of the preceding aspects from 69th to 85th the step of stretching is carried out at a temperature between 65 °C and 110 °C. In an 87th aspect according to any one of the preceding aspects from 68th to 86th the step of stretching of the first precursor bodies is carried out at a temperature between 75 °C and 90 °C. In an 88th aspect according to any one of the preceding aspects from 69th to 87th the step of stretching of the first precursor bodies is carried out in a water bath.

[0062] In an 89th aspect according to any one of the preceding aspects from 69th to 88th, the step of stretching of the second precursor bodies is carried out at a temperature between 85 °C and 110 °C. In a 90th aspect according to any one of the preceding aspects from 69th to 89th the step of stretching of the second precursor bodies is carried out in air, optionally in a casing within which there is air heated at a temperature between 85 °C and 110 °C.

[0063] In a 91st aspect according to any one of the preceding aspects from 68th to 90th, the step of extrusion is carried out at a speed between 5 meters per minute and 12 meters per minute, optionally between 6 meters per minute and 10 meters per minute.In a 92nd aspect according to any one of the preceding aspects from 69th to 91st the stretching speed of the first precursor bodies to define said stretched first elements (3) is carried out, along the advancement direction (MD), at a speed comprised between 23 meters per minute and 27 meters per minute. In a 93rd aspect according to any one of the preceding aspects from 69th to 92nd the stretching speed of the second precursor bodies to define said stretched second elements (4) is carried out, along a direction orthogonal to the advancement direction (MD), at a speed comprised between 4 meters per minute and 200 meters per minute, optionally between 20 meters per minute and 100 meters per minute.

[0064] In a 94th aspect is provided a turf comprising:

[0065] a soil layer,

[0066] a predetermined quantity of grass emerging from a side of the soil layer,

[0067] at least a reticular structure (2), according to any one of the preceding aspects from 1st to 65th, engaged to the soil layer.

[0068] In a 95th aspect according to the preceding aspect the reticular structure (2) is configured, in use, to consolidate at least the soil layer. In a 96th aspect according to any one of the two preceding aspects the soil layer extends in thickness between a first and a second surface, optionally the thickness of the soil layer is greater than 0,5 cm, optionally is between 0,65 cm and 2,5 cm. In a 97th aspect according to any one of the three preceding aspects the turf comprises at least a grass sod has a surface extension greater than 0,25 m2, optionally is between 0,25 m2and 1,5 m2.

[0069] In a 98th aspect is provided a process for the realization of a turf, optionally in accordance with any one of the aspects from 94th to 97th. In a 99th aspect according to the preceding aspect the process comprises the following steps:

[0070] laying the reticular structure (2) in accordance with any one of the preceding aspects from 1st to 65th on a portion of land,

[0071] optionally covering at least in part the reticular structure (2) with a soil layer.

[0072] sowing the portion of land by laying grass seed,

[0073] during the step of turf growth, pre-conditioning the reticular structure (2) in a biologically active environment to initiate a degradation step of the reticular structure (2).

[0074] In a 100th aspect according to the preceding aspect the step of pre-conditioning the reticular structure (2) comprises at least one of the following sub-steps:

[0075] maintaining the reticular structure in an environment containing natural or induced microbiological activity, maintaining the reticular structure in an environment with controlled humidity and / or temperature parameters,treating the portion of land and thus the reticular structure with at least one fertilizer, optionally comprising nitrogen, phosphorus and calcium,

[0076] irrigating the portion of land.

[0077] In a 101st aspect according to the preceding aspect the step of pre-conditioning the reticular structure (2) is carried out for a period between at least 4 months and 18 months, optionally between 8 and 12 months. In a 102nd aspect according to any one of the two preceding aspects the step of pre-conditioning provides for the step of irrigating the portion of land from 1 to 3 times per week. In a 103rd aspect according to any one of the three preceding aspects the step of pre-conditioning the reticular structure (2) comprises treating the portion of land by means of organic or slow-release fertilizers. In a 104th aspect according to any one of the four preceding aspects the environment containing natural or induced microbiological activity comprises at least one chosen in the group of: compost, farm soil, natural soil, microbial beds.

[0078] In a 105th aspect according to any one of the five preceding aspects the process, after the growth of grass on the portion of land and at the end of the step of pre-conditioning the reticular structure (2), comprises the steps of:

[0079] carrying out a cut in the ground for the delimitation of the turf,

[0080] collecting the turf comprising a soil layer, the reticular structure (2) partially degraded and a turf, laying said turf on a definitive portion of land.

[0081] In a 106th aspect according to the preceding aspect the step of collecting the turf is carried out after a period between 3 and 14 months, optionally between 5 and 8 months, starting from the step of sowing the portion of land. In a 107th aspect according to any one of the two preceding aspects the reticular structure (2) is configured to degrade at least 80% of the initial mass, optionally in at least one of the following compounds CO2, H2O, H2, CH4, within 3-5 years from the step of pre-conditioning the reticular structure.

[0082] In a 108th further aspect is provided a grass roll (R) wound around an axis and comprising:

[0083] a soil layer,

[0084] a predetermined quantity of grass emerging from a side of the soil layer,

[0085] at least a reticular structure (2) in accordance to any one of the preceding aspects from 1st to 65th, at least in part degraded.

[0086] In a 109th aspect according to the preceding aspect the reticular structure (2) being configured, in use, to consolidate at least the soil layer. In a 110th aspect according to the preceding aspect the percentage of degradation of the reticular structure (2) is between 20% and 60% of the initial mass of the reticular structure (2), optionally between 30% and 50% of the initial mass of the reticular structure (2).

[0087] In a 111 th according to any one of the two preceding aspects the grass roll (R), fully unwound and laid on a plane, has a length between 1 meter and 40 meters; said length being measured along an unwinding directionof the grass roll (R) itself. In a 112th aspect according to any one of the three preceding aspects the roll has a width greater than 0,6 meters, optionally between 0,6 meters and 2 meters; said width being measured along the axis around which said grass roll results wound.

[0088] In a 113th aspect according to any one of the four preceding aspects the grass roll (R), fully unwound and laid on a plane, has a surface extension greater than 0,6 m2, optionally is between 1 m2and 1,5 m2.

[0089] In a 114th aspect is provided a use of the reticular structure (2) in accordance with any one of the preceding aspects from 1st to 65th for at least one of: consolidation of the land, the reinforcement of the land.

[0090] In a 115th aspect is provided a granular compound, optionally realized by means of a process of compounding, realized in material comprising:

[0091] a polymeric composition,

[0092] a degradation additive.

[0093] In a 116th aspect according to the preceding aspect the polymeric composition is in weight percentage more than 80% with respect to the total weight of the granular compound, optionally between 85% and 99% with respect to the total weight of the granular compound material, even more optionally between 90% and 98% with respect to the total weight of the granular compound material, for example between 92% and 97% with respect to the total weight of the granular compound material.

[0094] In a 117th aspect according to any one of the two preceding aspects the polymeric composition comprises polyolefin. In a 118th aspect according to any one of the three preceding aspects the polymeric composition is of the thermoplastic type. In an 119th aspect according to any one of the four preceding aspects the polymeric composition comprises at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof. In a 120th aspect according to any one of the five preceding aspects the polymeric composition is constituted only by at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof. In a 121st aspect according to any one of the six preceding aspects the polymeric composition comprises at least one of the following materials: polyethylene, polypropylene. In an 122nd aspect according to any one of the seven preceding aspects the polymeric composition is constituted by polyethylene. In a 123rd aspect according to any one of the eight preceding aspects the polymeric composition is constituted by polypropylene.

[0095] In a 124th aspect according to any one of the preceding aspects from 115th to 123rd the material of the granular compound comprises a percentage by weight of degradation additive between 1,5% and 15% with respect to the total weight of the material of the granular compound, optionally between 2% and 20%, even more optionally between 3% and 8%, with respect to the total weight of said material of the granularcompound. In a 125th aspect according to any one of the preceding aspects from 115th to 124th, the degradation additive comprises at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose. In a 126th aspect according to any one of the preceding aspects from 115th to 125th the degradation additive is configured to generate at least an enzymatic process to allow the scission of the polymeric material.

[0096] In a 127th aspect according to any one of the preceding aspects from 115th to 126th the granular compound material:

[0097] polyolefin by weight between 90% and 98% with respect to the total weight of the granular compound material,

[0098] the stabilization additive by weight between 2% and 10% with respect to the total weight of the granular compound.

[0099] In a 128th aspect according to the preceding aspect the degradation additive comprises at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose. In a 129th aspect according to any one of the two preceding aspects the polyolefin comprises at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof.

[0100] In a 129th aspect according to any one of the preceding aspects from 115th to 128th the granular compound material comprises one or more additives, optionally comprising at least one of: a compatibilizing additive, a filler additive.

[0101] In a 130th aspect according to the preceding aspect the compatibilizing additive is configured to increase at least one of the adhesion, the mixability or the cohesion between polymeric components of different nature. In a 131st aspect according to the preceding aspect the compatibilizing additive is polymer-based. In a 132nd aspect according to any one of the two preceding aspects the granular compound material comprises a quantity of compatibilizing additive between 0,1% and 2% with respect to the total weight of the granular compound material. In a 133rd aspect according to any one of the three preceding aspects the compatibilizing additive comprises at least one of the following materials: polypropylene grafted with maleic anhydride, polyethylene grafted with maleic anhydride, ethylene-vinyl acetate, styrene-ethylene-butylene-styrene grafted with maleic anhydride. In a 134th aspect according to any one of the four preceding aspects the material can comprise a compatibilizing additive chosen among copolymers grafted with maleic anhydride, as PP-g-MAH, PE-g-MAH or SEBS-g-MAH, or an ethylene-vinyl acetate copolymer with high content of VA (high EVA VA), suitable for improving the compatibility between the olefin matrix and polar or degradable components.In a 135th aspect according to any one of the aspects from 129th to 134th the filler additive is configured to change the physical-mechanical properties of the granular compound material. In a 136th aspect according to any one of the aspects from 129th to 135th the granular compound material comprises a quantity of filler additive between 0,5% and 10% with respect to the total weight of the granular compound material. In a 137th aspect according to any one of the aspects from 129th to 136th the filler additive comprises at least one of: industrial agricultural waste, wood processing waste, materials composed of natural polymers. In a 138th aspect according to any one of the aspects from 129th to 137th the filler additive comprises at least one of: cellulose, corn starch, natural rubber, linseed oil, wheat glume, wood flour, quill keratin hydrolysate, sodium lignosulfonate, seed shells, birch leaves or the like, hay, fruit waste, date palm wood, cellulose, hemicellulose and lignin.

[0102] SHORT DESCRIPTION OF FIGURES

[0103] Some embodiments and some aspects of the invention will be described below with reference to the attached drawings, provided for illustrative purposes only and therefore in a non-limiting extent in which:

[0104] - Figure 1 shows a reticular structure according to the present invention;

[0105] - Figure 2 shows a possible application on the ground of a reticular structure according to the present invention;

[0106] - Figures 3 to 5 show steps of a process for the realization of a turf;

[0107] - Figure 6 is a schematic view showing a possible realizing process of the reticular structure according to the present invention.

[0108] DEFINITIONS AND CONVENTIONS

[0109] It is to be noted that in the present detailed description corresponding parts shown in the various figures are indicated by the same numerical references. Figures could show the object of the invention by means of representations that are not to scale; therefore, parts and components shown in figures related to the object of the invention could only relate to schematic representations.

[0110] In the present document, the term ‘polymer1or ‘polymeric material or ‘polymeric composition’ is used for indicating both homopolymers, consisting of repeating units of a single type of monomer, and copolymers, comprising units derived from two or more different monomers. The expression polymeric material designates a material comprising at least one polymer.The term 'polyolefin' refers to a polymer or copolymer derived from the polymerization of alpha-olefins (a-aliphatic olefins), optionally selected from ethylene, propylene, 1 -butene, 1 -hexene, and the like. These materials comprise, by way of example, but not limited thereto, polyethylene (PE), polypropylene (PP), polybutene (PB), ethylene-propylene copolymers (EPR), ethylene-vinyl-acetate copolymers (EVA), ethylene / a-olefin copolymers, combinations thereof.

[0111] The term ‘advancement direction’ (MD) refers to a direction of movement of an initial semi-finished product formed by an extrusion station and which proceeds along an advancement path through a cooling station, optionally a stretching station, and then on to a collecting station. The advancement direction, in the technical field, is also called ‘machine direction’.

[0112] With the term ‘biodegradable’ is intended a material (of natural or synthetic origin) capable of degrading over time, optionally through enzymatic processes, for example by the action of bacteria, fungi or through interaction with other microorganisms.

[0113] With the term ‘stretched’ in relation to first and / or second elements of the reticular structure object of the present invention is intended a process that allows to elongate said elements in such a way as to arrange the molecular chains that form the latter (said first and / or second elements 3, 4) according to an orientation markedly oriented along the development direction of the elements themselves. Depending on the degree of stretching, the elements may have a more or less subtle structure and may also assume substantially threadlike conformation. As will be better described later, stretching is carried out from a monolithic semi-finished product with a reticular structure having first precursor bodies substantially spaced from each other intersected with second precursor bodies also substantially spaced from each other: the first and second precursor bodies essentially form a net with square or rectangular meshes in which at least the first precursor bodies can, in a non-limiting extent, extend parallel to the extrusion direction. The stretching ratio is also defined as the ratio of a stretched element to the length of the relative precursor body capable of defining, as a result of the stretching action, said stretched element.

[0114] With the term ‘compounding’ is intended a process that allows to prepare a composition by mixing and / or blending solutions and additives in the molten state to obtain a solid compound in granular form realized with said composition and thus having predetermined characteristics. The granular compound is then used in a process of extrusion for realizing reticular structures, for example nets. The reticular structure object of the present invention is realized by means of a process of extrusion using a solid compound in granular form thecomposition thereof is obtained by means of heating and mixing, within a mixing extruder, a predetermined quantity of olefinic polymeric material, additivated with at least one degrading additive; once the composition has been mixed to achieve a uniform composition the same is passed through a die and appropriately cut to obtain granular material with which to feed the process extruder in a subsequent step. The extrusion by mixing by means of a worm screw is configured to compress the material and guide it out through a die from which the composition emerges in the form of threads; the threads are then cut by means of rotating blades and cooled in a water bath, or by spraying, to produce the solid compound in granular form (also known as a 'compound').

[0115] DETAILED DESCRIPTION

[0116] Reticular structure

[0117] With 2 it has been overall indicated a reticular structure usable, for example, for soil consolidation or to promote soil compaction. More generally, the reticular structure 2 finds application for uses in which the presence of the reticular structure 2 is requested - for example for consolidation and / or reinforcement purposes - for a predetermined period of time and wherein it is preferable that there is a biodegradation of it after the 'useful' period from the reticular structure 2. By useful period is intended the time period during which it is necessary that the reticular structure 2 is substantially intact and capable of correctly performing the required function, i.e. for purposes of consolidation and / or reinforcement.

[0118] As it can be seen from figure 1, the reticular structure 2 comprises a plurality of first elements 3 spaced and parallel from each other parallel; the first elements 3 are interconnected to a plurality of second elements 4 spaced and parallel to each other too: the plurality of second elements 4 are transversally placed, in particular orthogonally, to the first elements 3.

[0119] In detail, each first element extends along the entire reticular structure 2 and is formed by a plurality of portions aligned along a same line. Analogously, each of said second elements 4 extends too along the entire reticular structure 2 transversally to the first elements 3 and is formed by a plurality of portions aligned along a same line: each first element 3 is intersected by a plurality of second elements 4 and each second element 4 is intersected by a plurality of first elements 3 at nodes 5 to form meshes 6. The reticular structure 2 defines a monolithic grid (net), i.e. in a single piece, exclusively constituted by said first and second elements 3, 4. In detail, the first elements 3 have an elongated conformation according to a first development trajectory T1 (figure 1). As it can be seen in the attached figures, the trajectories T1 are parallel to each other to define a plurality of first elements 3 parallel to each other. Said first trajectories can be substantially rectilinear in such a way as to form straight and elongated first elements along parallel directions. The first elements 3 have, at least at a centerline portion defined between two immediately consecutive nodes 5 and orthogonally to thefirst development trajectory T1 , a section having substantially elliptical shape. It is not excluded the possibility of realizing first elements 3 having, at least at a centerline portion defined between two immediately consecutive nodes 5 and orthogonally to the second development trajectory, a section having for example rectangular, square, circular, or “T” shape. The first elements 3 have a substantially threadlike structure and have then along their entire development a reduced cross section; for example, the first elements 3 may have a cross section, measured at a centerline portion defined between two immediately consecutive nodes, of area lower than 5 mm2, optionally between 0,1 mm2and 1,5 mm2. The cross section remains substantially constant, for example full, for the entire development of the first element 3 with an increase in section at the nodes where the first element extends to join with said second elements 4. In particular, each first element 3 can define, between two immediately consecutive nodes for at least 80% of its total extent, a change in terms of area of the transversal section less than 20%, optionally less than 15%, even more optionally less than 10%; wherein said section is defined according to a plane orthogonal to the direction of extension of said tract.

[0120] Each first element 3 has furthermore a tract that connects two immediately consecutive nodes 5 which has a surface-to-volume ratio greater than 5 mm1, optionally 10 mm1; the surface-to-volume ratio is defined as the ratio between the area of the external surface of said tract and the volume of the same tract.

[0121] Also the second elements 4 have an elongated conformation according to a second development trajectory T2. As it can be seen in the attached figures, the trajectories T2 are parallel to each other to define a plurality of second elements 4 parallel to each other. Said second trajectories T2 can be substantially rectilinear in such a way as to form straight and elongated first elements along parallel directions.

[0122] The second elements 4 have, at least at a centerline portion defined between two immediately consecutive nodes 5 and orthogonally to the second development trajectory T2, a section having substantially elliptical shape. It is not excluded the possibility of realizing second elements 4 having, at least at a centerline portion defined between two immediately consecutive nodes 5 and orthogonally to the second development trajectory, a section having for example rectangular, square, circular, or “T” shape.

[0123] The first and second elements 3, 4 lay substantially on a same plane; said first and second elements 3, 4 define essentially a net having a substantially plane conformation. The second elements 4 have a substantially threadlike structure and have then along their entire development a reduced cross section; for example, the second elements 4 may have a cross section, measured at a centerline portion defined between two immediately consecutive nodes 5, of area lower than 5 mm2, optionally between 0,1 mm2and 1,5 mm2. The cross section, for example full, remains substantially constant for the entire development of the second element 4 with an increase in section at the nodes 5 where the second element 4 extends to join with said first elements 3. In particular, each second element 4 can define, between two immediately consecutivenodes, which has, for at least 80% of its total extent, a change in terms of area of the transversal section less than 20%, optionally less than 15%, even more optionally less than 10%; wherein said section is defined according to a plane orthogonal to the direction of extension of said tract. The ratio between an area of a transversal section of a first element 3, measured at an intermediate portion between two immediately consecutive nodes 5, and an area of a transversal section of a second element 4, measured too at an intermediate portion between two immediately consecutive nodes 5, can be between 0,5 and 2, optionally between 0,7 and 1,2.

[0124] Furthermore, each second element 4 has a tract that connects two immediately consecutive nodes 5 which has a surface-to-volume ratio greater than 5 mm1, optionally 10 mm1; the surface-to-volume ratio is defined as the ratio between the area of the external surface of said tract and the volume of the same tract.

[0125] From a dimensional profile, two immediately adjacent first elements 3 with respect to a direction orthogonal to the development trajectory of at least one of said adjacent first elements are placed at a minimum distance from each other between 5 mm and 70 mm, optionally between 10 mm and 25 mm; analogously, two immediately adjacent second elements 4 with respect to a direction orthogonal to the development trajectory of at least one of said adjacent second elements are placed at a minimum distance from each other between 5 mm and 70 mm, optionally between 12 mm and 45 mm. The ratio between the distance between the two adjacent first elements 3 and the distance between two adjacent second elements 4 is between 0,5 and 2, optionally between 0,8 and 1,2.

[0126] As these distances vary the size of meshes 6 varies which may have a through-area between 16 mm2and 40000 mm2, optionally between 200 mm2and 3000 mm2. The meshes 6 of the reticular structure 2 are substantially square. It is not excluded the possibility of realizing meshes having different shape, for example rectangular, triangular or rhomboidal.

[0127] The reticular structure 2 can be, in a non-limiting extent, stretched along at least one direction of extension of the first elements 3 and / or second elements 4 to define a single-stretched and / or double-stretched reticular structure 2; for example, the reticular structure 2 can be stretched along the development of only the first elements 3, i.e., along the first trajectory T1. The reticular structure 2 can be stretched along two directions, in particular along the development of the first and second elements 3, 4 to define a double-stretched reticular structure as shown for example in figure 1: in such a configuration the reticular structure results stretched both along the first trajectory T1 and along the second trajectory T2. The stretching ratio, i.e., the ratio between the length of the elements (first elements and / or second elements) after the stretching and their length before the stretching is greater than 1,5.

[0128] In detail, the first elements 3 are stretched along the first trajectory T1 : the stretching ratio of a first element 3 is defined as the ratio between a final length of the same first element once the stretching is carried outand the initial length of such first element before the stretching action. The first elements 3 have a stretching ratio greater than 1,5, optionally between 2 and 8, more optionally between 2,5 and 4.

[0129] The second elements 4 are stretched along the second trajectory T2: the stretching ratio of a second element 4 is defined as the ratio between a final length of the same first element once the stretching is carried out and the initial length of such second element before the stretching action. The second elements 4 have a stretching ratio greater than 1.5, optionally between 2 and 5, more optionally between 2 and 4.

[0130] The threadlike structure of the first and second elements 3, 4 is substantially defined by the stretching action, which accentuates the elongation of said elements and thins their transversal section.

[0131] The reticular structure 2 has substantially two development directions (i.e. the directions wherein the first elements 3 and the second elements 4 extend): the structure 2 has a height, or total thickness, orthogonally to these development directions much lower than with respect to the size defined in the two development directions (for example length and width of the reticular structure 2) to define a reticular structure 2 having substantially uni-planar shape.

[0132] The height of the reticular structure 2 is defined by the height (maximum) of the first and / or second elements 3, 4 thus by the height defined at nodes 5.

[0133] From a structural profile, it is possible to define an areal mass of the reticular structure which is between 3 g / m2and 30 g / m2, optionally between 5 g / m2and 15 g / m2. The reticular structure can have a specific tensile resistance, along the first and / or second elements equal to or greater than 0,5 kN / m, in particular between 0,7 kN / m and 10 kN / m, even more optionally between 0,7 kN / m and 3 kN / m; the specific tensile resistance is measured with the method given in ASTM D7179.

[0134] The reticular structure 2 as a whole is biodegradable, i.e., realized in material capable of degrading completely within 3-5 years (or in any case at least 80% within 3-5 starting from when placed, in use, in contact with the land to exert the action of consolidation and / or reinforcement). In particular, the reticular structure 2 is realized with at least two materials to define a composition, as a whole, degradable (optionally biodegradable). In detail, the reticular structure 2 is realized at least partly of polymeric, non-degrading, optionally non-biodegradable material additivated by means of at least a degradation additive configured to promote, in use, the degradation of the reticular structure 2. In fact, the degrading additive has the purpose of binding to the polymeric matrix (itself not degrading) and contribute to form an 'accessible' polymeric matrix by leaching or providing water-soluble fractions. Such changes promote the microbial sensing quorum on the surface of the polymeric matrix, leading to enzyme production and eventual polymer chain cleavage. Mechanistically, the microbial action is mainly driven by enzymes that break carbon-carbon bonds, for example, when low molecular weight segments or carbonyl groups are present.In detail, the polymeric composition or polymer is in weight percentage more than 80% with respect to the total weight of the reticular structure 2 material, optionally between 85% and 99% with respect to the total weight of the reticular structure 2 material, even more optionally between 90% and 98% with respect to the total weight of the reticular structure 2 material. For example, in a preferred but non- limiting embodiment of the invention, the reticular structure material comprises a percentage of polymeric composition (or polymer) between 92% and 97%, with respect to the total weight of the reticular structure 2 material.

[0135] In detail, the polymeric composition comprises polyolefin, optionally comprises at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof. In an embodiment the polymeric composition is only constituted by at least one of the following materials: polyethylene, polypropylene. As for the degrading additive, on the other hand, this can be present, as a weight percentage of the total weight of the reticular structure 2 material, in a weight percentage between 1,5% and 15%, optionally between 2% and 10%, even more optionally between 3% and 8%. In detail, the degradation additive comprises at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose. The degradation additive is configured, in conditions of use of the reticular structure i.e. when it is in contact with the soil layer to reinforce and / or consolidate it, to generate at least an enzymatic process to allow the scission of the polymeric composition of the reticular structure 2 material. In fact, as above mentioned, the degradation additive is configured to degrade the reticular structure 2 by means of enzyme-driven microbial action, optionally to promote carbon-carbon bond breaking in such a way that the reticular structure, in use, can degrade completely by means of the action of microorganisms in at least one of: water, carbon dioxide, biomass, preventing the formation of plastic residues. In other words, the degradation additive makes the reticular structure 2 completely biodegradable and then non-polluting to the environment.

[0136] In an embodiment, the reticular structure 2 material comprising:

[0137] polyolefin by weight between 90% and 98% with respect to the total weight of the reticular structure 2 material,

[0138] the degradation additive by weight between 2% and 10% with respect to the total weight of the reticular structure 2 material.

[0139] The degradation additive can comprise at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose; the polyolefin can instead comprise at least one of the following materials: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof.

[0140] The reticular structure 2 material can comprise only polyolefins and at least one degradation additive to substantially define the 100% of the total weight of the reticular structure 2 material. It is not excluded howeverthe possibility of providing a material containing different additives. For example, the reticular structure 2 material can comprise furthermore at least one of: a compatibilizing additive, a filler additive.

[0141] The compatibilizing additive is configured to increase at least one between the adhesion, the mixability or the cohesion between polymeric compositions (or polymers) of different nature. Also the compatibilizing additive can be polymer-based and be present in the reticular structure 2 material in a percentage by weight between 0,1 % and 2% with respect to the total weight of the reticular structure 2 material. In detail, the compatibilizing additive can comprise at least one of the following materials: polypropylene grafted with maleic anhydride, polyethylene grafted with maleic anhydride, ethylene-vinyl acetate, styrene-ethylene-butylene-styrene grafted with maleic anhydride. For example, the material can comprise a compatibilizing agent chosen among copolymers grafted with maleic anhydride, as PP-g-MAH, PE-g-MAH or SEBS-g-MAH, or an ethylene-vinyl acetate copolymer with high content of VA (high EVA VA).

[0142] The filler additive, if present, is instead configured to change the physical-mechanical properties of the reticular structure 2 material. For example, the reticular structure 2 material can comprise a quantity of filler additive between 0,5% and 10% with respect to the total weight of the reticular structure 2 material. In detail, the filler additive can comprise at least one of: industrial agricultural waste, wood processing waste, materials composed of natural polymers. Still in greater detail, the filler additive comprises at least one of: cellulose, corn starch, natural rubber, linseed oil, wheat glume, wood flour, quill keratin hydrolysate, sodium lignosulfonate, seed shells, birch leaves or the like, hay, fruit waste, date palm wood, cellulose, hemicellulose and lignin.

[0143] As mentioned above, the particular composition of the reticular structure 2 material makes it fully degradable (for example biodegradable), within a certain period of time.

[0144] The biodegradability of the material with which it is realized the reticular structure 2 can be defined by means of a degradation parameter. The degradation parameter is representative of how the material with which it is realizable the reticular structure 2 reaches a predefined percentage of conversion to organic compounds, in particular CO2 and CH4, within a determined time horizon under standardized conditions.

[0145] The determination of the degradation parameter provides for the preparation of a test sample realized in the above-described material for the reticular structure 2 and the carrying out of a test according to ASTM D5511. From the tests carried out, it emerged that the sample has a degradation percentage parameter in organic compounds equal to or greater than 80% of the initial mass after a time range equal to or greater than three years when subjected to the test conditions prescribed by ASTM D5511. Conversely, the material with which the reticular structure 2 is realized allows the test sample subjected to the above-mentioned biodegradation process to maintain a certain structurality for an initial time frame of about 12 months, in such a way that saidtest sample can have in the period between the beginning of pre-conditioning and final laying (for example, up to 12-14 months) sufficient residual mechanical characteristics.

[0146] A further assessment of biodegradability is the one carried out in an environment simulating biologically active land, the particular composition of the reticular structure 2 material makes it completely degradable (for example biodegradable), within a certain period of time within the soil.

[0147] The biodegradability of the material with which it is realized the reticular structure 2 in the soil can be defined by means of a degradation parameter. The degradation parameter is representative of how the material with which it is realizable the reticular structure 2 reaches a predefined percentage of conversion to organic compounds, in particular CO2 and CH4, within a determined time horizon under standardized conditions that simulate the standard soil.

[0148] The determination of the degradation parameter in the soil provides for the preparation of a test sample realized in the above-described material for the reticular structure 2 and the carrying out of a test according to ASTM D5338.

[0149] From the tests carried out it emerged that the sample has a degradation percentage parameter in organic compounds equal to or greater than 75% of the initial mass after a time range equal to or greater than two years when subjected to the test conditions prescribed by ASTM D5511.

[0150] Examples of materials usable for the reticular structure

[0151] In some embodiments, the material of the monolithic reticular structure can comprise a polymeric composition and a degradation additive, optionally in combination with one or more further additives, as a compatibilizing additive and / or a filler additive.

[0152] The compositions below indicated are expressed as a percentage by weight with respect to the total weight of the reticular structure material.

[0153] In preferred embodiments, the degradation additive comprises polylactic acid (PLA) and / or polyhydroxyalkanoates (PHA), optionally in combination with starch, while the one or more additives can comprise a maleic compatibilizing agent and, optionally, a lignocellulosic filler in small amounts.

[0154] Example 1

[0155] In an embodiment, the material of the reticular structure comprises:

[0156] - polypropylene in amount equal to 96,0% by weight;

[0157] - polylactic acid (PLA) in amount equal to 3,0% by weight;polypropylene grafted with maleic anhydride (PP-g-MAH), as compatibilizing agent, in amount equal to 1,0% by weight.

[0158] In this example, therefore, the polypropylene constitutes the main component of the material and represents more than 90% by weight of the total weight of the material of the reticular structure, while the degradation additive is present in amount equal to 3,0% by weight.

[0159] Example 2

[0160] In an embodiment, the material of the reticular structure comprises:

[0161] - polypropylene in amount equal to 94,5% by weight;

[0162] - polyhydroxyalkanoates (PHA) in amount equal to 3,5% by weight;

[0163] - PP-g-MAH, as compatibilizing agent, in amount equal to 1,0% by weight;

[0164] - micronized cellulose, as filler additive, in amount equal to 1 ,0% by weight.

[0165] In this example, therefore, the degradation additive is present in amount falling in the range 2,5% - 5% by weight, while the micronized cellulose is present in reduced amount, such as not to compromise the processability of the material.

[0166] Example 3

[0167] In an embodiment, the material of the reticular structure comprises:

[0168] - polypropylene in amount equal to 95,0% by weight;

[0169] - PLA in amount equal to 2,5% by weight;

[0170] - starch in amount equal to 0,5% by weight;

[0171] - PP-g-MAH, as compatibilizing agent, in amount equal to 1,0% by weight;

[0172] - wood flour, as filler additive, in amount equal to 1 ,0% by weight.

[0173] In this example, the degradation additive comprises a plurality of components, in particular PLA and starch, for a total amount equal to 3,0% by weight, while the filler additive is maintained at a reduced level.

[0174] Example 4

[0175] In an embodiment, the material of the reticular structure comprises:- ethylene-propy lene copolymer with polypropylenic matrix in amount equal to 95,0% by weight; - PHA in amount equal to 3,0% by weight;

[0176] - PP-g-MAH, as compatibilizing agent, in amount equal to 1,0% by weight;

[0177] - micronized cellulose, as filler additive, in amount equal to 1 ,0% by weight.

[0178] This composition uses a copolymer of the polypropylene as main component of the polymeric composition and has a content of degradation additive equal to 3,0% by weight.

[0179] Example 5

[0180] In an embodiment, the material of the reticular structure comprises:

[0181] - ethylene-propylene copolymer with polypropylenic matrix in amount equal to 93,5% by weight; - PLA in amount equal to 4,0% by weight;

[0182] - PP-g-MAH, as compatibilizing agent, in amount equal to 0,5% by weight;

[0183] - wood flour, as filler additive, in amount equal to 2,0% by weight.

[0184] In this further example, the degradation additive is present in amount equal to 4,0% by weight, while the compatibilizing additive is present in amount lower than 1% by weight.

[0185] Example 6

[0186] In an embodiment, the material of the reticular structure comprises:

[0187] - polypropylene in amount equal to 92,.0% by weight;

[0188] - polyethylene in amount equal to 4,0% by weight;

[0189] - PLA in amount equal to 3,0% by weight;

[0190] - PP-g-MAH, as compatibilizing agent, in amount equal to 1,0% by weight.

[0191] In this example, the polymeric composition comprises polypropylene and polyethylene in a total amount equal to 96,0% by weight, while the degradation additive is present in amount equal to 3,0% by weight. It is intended that the aforementioned numerical values are provided for mere illustrative purposes and that the expert in the art can vary the nature and / or relative quantity of the components, provided that it is within the scope of the content of the claims.The currently preferred formulations are those in which the polymer matrix is mainly based on polypropylene or a copolymer of polypropylene.

[0192] The degradation additive, which for example comprises PLA and / or PHA, can be optionally in combination with a lignocellulosic filler in small amount and with a maleic compatibilizing agent.

[0193] Process of realization

[0194] It is also an object of the present invention a process for the realization of a reticular structure 2 in accordance with the above-indicated description and in accordance with any one of the attached claims.

[0195] The process provides for the formation of first and second elements 3, 4 by means of a process of extrusion (simultaneous extrusion of the first and second elements 3, 4), optionally by means of a pulsating technology. It is obviously not excluded the involvement of an extrusion head that uses a counter-rotating technology. The extrusion head is supplied by means of a solid compound in granular form realized by compounding. The solid granular compound is realized by means of degradable material (optionally biodegradable) in accordance with the above-described material for the reticular structure.

[0196] The process of extrusion, schematically represented in figure 6, provides for the simultaneous extrusion of first and second precursor bodies through an extrusion head 100; the first precursor bodies are longitudinal elements that extend along an extrusion direction E, then along an advancement direction MD of the material extruded out from the head 100 while the second precursor bodies are elements transversal to the first precursor bodies: the first and second precursor bodies forming a monolithic entire reticular body. The advancement direction MD is furthermore recognized in the field as machine direction, i.e. the direction in which the extrusion equipment and formation of the reticular structure makes the latter move.

[0197] The step of extrusion is carried out at a temperature between 140 °C and 240 °C, optionally between 180 °C and 230°C; the material exiting from the extrusion head is advanced between 5 meters per minute and 12 meters per minute, optionally between 6 meters per minute and 10 meters per minute. The extrusion can be carried out with a cylindrical head capable of forming a reticular structure having a cylindrical shape. Subsequently such reticular structure exiting from the extrusion head is cooled to be longitudinally cut in order to be then opened and spread flat. In figure 6 is shown a cutting station 101 of the cylindrical reticular structure and a subsequent spreading station 102 in which the open reticular structure is spread on a single plane.

[0198] The spread reticular structure can define the reticular structure 2 having non-stretched first and second elements. Once spread, said structure is ready to be wound into a roll in a collection station (not shown). Alternatively, subsequently to the formation of the monolithic entire body, this latter can undergo a stretching process. In this configuration, the reticular structure exiting from the extrusion head essentially defines amonolithic semi-finished product with reticular structure having first and second precursor bodies spaced and interconnected to each other to essentially define a semi-finished product in form of net. In a preferred but non-limiting embodiment, the semi-finished product is extruded through a head that uses a pulsating technology; in this configuration, the first precursor bodies extend along the direction of extrusion while the second precursor bodies extend orthogonally to said first precursor bodies to define a semi-finished product with square or rectangular meshes.

[0199] Subsequently such monolithic semi-finished product with reticular structure exiting from the extrusion head is cooled to be longitudinally cut, i.e. along the development direction of the first precursor bodies to be then opened and stretched in plane. In figure 6 is shown a cutting station 101 of the monolithic semi-finished product with reticular structure and a subsequent spreading station 102 in which said semi-finished product is spread on a single plane. When spread in plane the first precursor bodies define longitudinal bodies extending along the advancement direction MD while the second precursor bodies define transversal bodies placed orthogonally to the advancement direction.

[0200] The semi-finished product when spread can be stretched along the first and / or second precursor bodies. The process can for example carry out the step of stretching only the first precursor bodies or only the second precursor bodies to define a single-stretched reticular structure 2. Alternatively, the realizing process can provide for a double stretching action, i.e. both along the development of the first precursor bodies and along the development of the second precursor bodies to define a double-stretched reticular structure (or also called double-oriented).

[0201] In figure 6 it is shown, in a non-limiting extent, a process that provides for the stretching both of the first and of the second precursor bodies. For example, the process can provide for a first stretching action of the first precursor bodies in a longitudinal stretching station 103 placed right downward the spreading station. The stretching of the first precursor bodies to define said first elements 3 stretched can be carried out by means of the movement of the semi-finished product along the advancement direction at a speed greater than the extrusion one to allow an elongation of the semi-finished product along the machine direction; for example, the stretching speed of the first precursor bodies - to define said first elements 3 stretched - is carried out, along the advancement direction MD, at a speed between 25 meters per minute and 40 meters per minute. During the step of stretching, the semi-finished product is heated up to a temperature between 65 °C and 110 °C. In particular, the step of stretching of the first precursor bodies is carried out, optionally in a water bath, at a temperature between 75 °C and 98 °C. It is obviously not excluded carrying out the step of stretching of the first precursor bodies still when the semi-finished product with reticular structure is in its circular shape i.e. before the step of cutting.The process can also provide for a second stretching action carried out on the second precursor bodies in a transversal stretching station 104 placed downward the spreading station, in particular right downward the longitudinal stretching station 103. The stretching of the second precursor bodies to define said second elements 4 can be carried out by means of a step of stretching, for example by means of grippers, of the semi-finished product with reticular structure according to a direction orthogonal to the advancement direction. The stretching speed of the second precursor bodies - to define said second elements 4 stretched - is carried out at a speed between 10 meters per minute and 200 meters per minute, optionally between 25 meters per minute and 150 meters per minute. The step of stretching of the second precursor bodies is carried out, optionally in a casing within which there is heated air, at a temperature between 85 °C and 140 °C. It is obviously not excluded carrying out the step of stretching of the second precursor bodies before the stretching of the first precursor bodies. After the formation of the reticular structure and then of the first and second elements 3, 4 (optionally stretched), the reticular structure is then cut transversally to the first elements according to a predetermined length, measured in direction of the first elements 3 to define said reticular structure 2. The reticular structure 2 can be, before the cutting step, wound in roll in a collecting station.

[0202] The process can also furthermore provide for different steps for the realization of the reticular structure, for example the realization of a reticular semi-finished product obtained by means of a plane extrusion head to realize a sheet that will then undergo the steps of cold drilling and stretching to obtain the reticular structure 2.

[0203] Process for the realization of a turf

[0204] It is also object of the present invention a process for the realization of a turf, comprising, for example, at least one of a soil strip upon which there is a turf, a grass sod 1.

[0205] The process comprises a first step of laying of the reticular structure 2 in accordance with the abovedescribed on a portion of land (see the second step shown in figure 3). In detail, the reticular structure 2 can be in a roll and unwound, then laid, on the portion of land. The reticular structure 2 can be then laid upon (leaning) the exposed surface of the land or can be pressed against the land in such a way that at least part of said reticular structure 2 can dip into the land, nonetheless remaining close to the exposed surface. It is also possible to provide for a step of laying the reticular structure on first soil layer later covered by a second soil layer: first and second soil layers form a soil layer in which at least part of the reticular structure 2 is embedded. The soil layer can, for example have a thickness greater than 0,5 cm, optionally is between 0,65 cm and 2,5 cm.After the laying (spreading) of the reticular structure 2, the process comprises a step of sowing the land by means of laying grass seeds. After the sowing, the grass follows the normal growth process that can last, for example as a function of the conditions and treatments of the land, from 6 months to 14 months. During the step of growth of the grass the reticular structure is configured to embed itself within the soil layer and the grass to allow soil consolidation.

[0206] The process, during the step of turf growth, provides for a step of pre-conditioning the reticular structure 2. This step is configured to initiate a degradation step of the reticular structure 2. This step of pre-conditioning the reticular structure 2 can comprise at least one of the following sub-steps:

[0207] maintaining the reticular structure in an environment containing natural or induced microbiological activity, maintaining the reticular structure in an environment with controlled humidity and / or temperature parameters,

[0208] treating the portion of land and thus the reticular structure with at least one fertilizer, optionally comprising nitrogen, phosphorus and calcium,

[0209] irrigating the portion of land.

[0210] The step of pre-conditioning the reticular structure 2 is carried out for a period between at least 4 months and 18 months, optionally between 8 and 12 months. Each of the above-described steps can occur only once or with a certain periodicity; for example, the step of irrigating the portion of land can be carried out from 1 to 3 times per week for the entire duration of the step of pre-conditioning.

[0211] After the growth of the grass on the portion of land and at the end of the step of pre-conditioning, the process provides for a cutting step in the ground for the delimitation of the turf. This step allows to cut both the soil layer bearing the turf, and the degraded reticular structure embedded in the soil layer. The reticular structure 2 so embedded, even if partially embedded, allows to reinforce and consolidate the turf, which can be then collected to be transported and laid on a definitive portion of land.

[0212] In figure 3 (last two diagrams) are shown the steps of collecting the turf. In figure 3 it is shown, in a nonlimiting extent, a turf collected in roll form; it is obviously not excluded the possibility of collecting the turf in strips or grass sods.

[0213] In figure 4 and 5 are schematized the steps of laying the turf on a definitive portion of land. In these figures the step of laying provides for, in a non-limiting extent, a step of unwinding a grass roll R. As it can be seen in figure 5, after the laying, the reticular structure 2 at least in part degraded cannot be seen since it is covered by the turf G or embedded in the soil layer S.

[0214] Grass rollIt is also an object of the present invention a grass roll R comprising a reticular structure 2 as described above and / or in accordance with any one of the attached claims.

[0215] The grass roll R is wound around an axis according to a spiral pattern (see for example figures 3 and 4) and comprises a soil layer S, a predetermined amount of grass G emerging from a side of the soil layer and at least a reticular structure 2 engaged to the soil layer. The reticular structure can be at least in part degraded but in any case configured, in use, to consolidate at least the soil layer S; the soil layer S extends in thickness between a first and a second surface, optionally the thickness of the soil layer is greater than 0,5 cm, optionally is between 0,65 cm and 2,5 cm.

[0216] The grass roll R, fully unwound and laid on a plane, has a length between 1 meter and 40 meters; said length being measured along an advancement direction of the grass roll R itself. The roll R has a width equal to or greater than 0,6 meters, optionally between 0,6 meters and 2 meters; said width being measured along the axis around which said grass roll is wound.

[0217] Grass sod

[0218] It is also an object of the present invention a grass sod 1 comprising a reticular structure 2 as described above and / or in accordance with any one of the attached claims.

[0219] The grass sod 1 comprises a soil layer S, a predetermined amount of grass G emerging from a side of the soil layer and at least a reticular structure 2 housed at least partly in the soil layer in an at least partially degraded condition. The reticular structure 2 is configured, in use, to consolidate at least the soil layer; the soil layer extends in thickness between a first and a second surface, optionally the thickness of the soil layer S is greater than 0,5 cm, optionally is between 0,65 cm and 2,5 cm; the grass sod has a surface extension greater than 0,25 m2, optionally is between 0,25 m2and 1,5 m2.

[0220] ADVANTAGES

[0221] The present invention involves, with respect to state-of-the-art solutions, considerable advantages. In particular, the reticular structure combines the low cost, easy processability, high mechanical characteristics and prolonged shelf life of polyolefins with the ability to degrade within a horizon of several years to a percentage of at least 80% of the initial mass in compounds or substances such as: carbon dioxide, water, molecular hydrogen and methane.

[0222] The reticular structure with pronounced openings and therefore a reduced mass per square meter, a relatively high exposed surface area promote on the one hand the anchorage to the ground and to the root system of the turf (in particular at turf formation) and on the other hand the degradation phenomena once the formed turf comprising the reticular structure is placed in place and then laid down at its final destination.In accordance with an aspect, the described solution can also make available a process of pre-conditioning that promotes the start of degradation, before finally laying the reticular structure 2 in the location where complete degradation will occur. This process allows to define a process for the realization of turfs capable of effectively consolidating the turf during the growth of the grass until the step of collecting.

[0223] The process of pre-conditioning, the composition of the reticular structure, and the specific reticular geometry of the structure (2) ensure then the complete or almost complete degradation of the reticular structure 2 preventing the formation of micro-plastics, avoiding then the pollution of the environment.

Claims

CLAIMS1. Monolithic reticular structure (2) comprising:- a plurality of first elements (3) spaced from each other and having an elongated conformation according to a first development trajectory (T1 ),- a plurality of second elements (4) spaced from each other and having an elongated conformation according to a second development trajectory (T2) transverse, optionally orthogonal, to the first development trajectory (T1) of the first elements (3),wherein said first and second elements (3, 4) intersect at nodes (5) to form meshes (6),wherein the reticular structure (2) is at least partially made of material comprising:a polymeric composition,a degradation additive configured to promote, in use, the degradation of the reticular structure (2).

2. Reticular structure according to the preceding claim, wherein the polymer composition is more than 80% by weight of the total weight of the reticular structure (2) material, optionally between 85% and 99% by weight of the total weight of the reticular structure (2) material.

3. Reticular structure according to any one of the preceding claims, wherein the polymeric composition comprises at least one of: polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl-acetate copolymers, ethylene / o-olefin copolymers, combinations thereof.

4. Reticular structure according to any one of the preceding claims, wherein the polymeric composition comprises polypropylene.

5. Reticular structure according to any one of the preceding claims, wherein the polymeric composition comprises polypropylene and wherein the polypropylene represents more than 80% by weight of the total weight of the reticular structure (2) material.

6. Reticular structure according to any one of the preceding claims, wherein the polymeric composition comprises polypropylene, and wherein the polypropylene represents more than 85% by weight of the total weight of the reticular structure (2) material, in particular wherein the polypropylene represents more than 90% by weight of the total weight of the reticular structure (2) material, for example 91 %, 92%, 93%, 94% or 95% by weight of the total weight of the reticular structure (2) material.

7. Reticular structure according to any one of the preceding claims, wherein the reticular structure (2) material comprises a percentage by weight of degradation additive between 1,5% and 15%, optionally between 2% and 10%, even more optionally between 3% and 8%, with respect to the total weight of said material.

8. Reticular structure according to any one of the preceding claims, wherein the degradation additive comprises at least one of: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose.

9. Reticular structure according to any one of the preceding claims, wherein the degradation additive comprises at least two or at least three of the following components: starch, nitric acid, polylactic acid, polyhydroxyalkanoates, sodium lactate, glucose.

10. Reticular structure according to any one of the preceding claims, wherein the reticular structure (2) material comprises a percentage by weight of degradation additive between 2,5% and 5% with respect to the total weight of said material, for example 3%.

11. Reticular structure according to any one of the preceding claims, wherein the degradation additive does not comprise bacteria or enzymes.

12. Reticular structure according to any one of the preceding claims, wherein the reticular structure (2) material comprises one or more further additives.

13. Reticular structure according to the preceding claim, wherein the one or more further additives comprise at least one of: a compatibilizing additive, a filler additive.

14. Reticular structure according to any one of the two preceding claims, wherein the reticular structure (2) material comprises a percentage by weight of compatibilizing additive between 0, 1 % and 2% with respect to the total weight of the reticular structure (2) material.

15. Reticular structure according to claim 13 or 14, wherein the compatibilizing additive comprises at least one of the following materials: polypropylene grafted with maleic anhydride, polyethylene grafted with maleic anhydride, ethylene-vinyl acetate, styrene-ethylene-butylene-styrene grafted with maleic anhydride.

16. Reticular structure according to any one of the three preceding claims, wherein the compatibilizing additive comprises at least one of: copolymers grafted with maleic anhydride, such as PP-g-MAH, PE-g-MAH or SEBS-g-MAH, orwherein the compatibilizing additive comprises an ethylene-vinyl acetate copolymer with high content of VA (high EVA VA).

17. Reticular structure according to any one of the four preceding claims, wherein the reticular structure (2) material comprises a percentage by weight of filler additive between 0,5% and 10% with respect to the total weight of the reticular structure (2) material.

18. Reticular structure according to any one of the five preceding claims, wherein the filler additive comprises at least one of: industrial agricultural waste, wood processing waste, materials composed of natural polymers, optionally the filler additive comprises at least one of: cellulose, corn starch, natural rubber, linseed oil, wheat glume, wood flour, quill keratin hydrolysate, sodium lignosulfonate, seed shells, birch leaves or the like, hay, fruit waste, date palm wood, cellulose, hemicellulose and lignin.

19. Reticular structure according to any one of the preceding claims, wherein each first element (3) has a tract that connects two immediately consecutive nodes (5), wherein said tract has a surface-to-volume ratio greater than 5 mm1, optionally greater than 10 mm1.

20. Reticular structure according to any one of the preceding claims, wherein each second element (4) has a tract that connects two immediately consecutive nodes (5), wherein said tract has a surface-to-volume ratio greater than 5 mm1, optionally greater than 10 mm1,wherein said surface-to-volume ratio is defined as the ratio between the area of the external surface of said tract and the volume of the same tract.

21. Reticular structure according to any one of the preceding claims, wherein the first elements (3) are stretched along their development, said first elements (3) having a stretching ratio between 2 and 8, optionally between 2,5 and 4; the stretching ratio of the first elements (3) is defined as the ratio between a final length of the first elements after a stretching action of them and an initial length of the first elements before stretching.

22. Reticular structure according to any one of the preceding claims, wherein the second elements (4) are stretched along their development, said second elements (4) having a stretching ratio between 2 and 8, optionally between 2,5 and 4; the stretching ratio of the second elements (4) is defined as the ratio of a final length of the second elements after a stretching action of them and an initial length of the second elements before stretching.

23. Reticular structure according to any one of the preceding claims, wherein the development trajectories (T1 ) of the first elements (3) are parallel to each other.

24. Reticular structure according to any one of the preceding claims, wherein the first elements (3) have a substantially threadlike structure.

25. Reticular structure according to any one of the preceding claims, wherein said first elements (3) have a transversal section, measured at a centerline portion defined between two immediately consecutive nodes, of area less than 5 mm2, optionally between 0,1 mm2and 1,5 mm2;in particular wherein the first elements (3) have a full cross section.

26. Reticular structure according to any one of the preceding claims, wherein the second development trajectories (T2) of the second elements are parallel to each other.

27. Reticular structure according to any one of the preceding claims, wherein the second elements (4) have a substantially threadlike structure.

28. Reticular structure according to any one of the preceding claims, wherein said second elements (4) have a transversal section, measured at a centerline portion defined between two immediately consecutive nodes, of area less than 5 mm2, optionally between 0,1 mm2and 1,5 mm2; in particular wherein the second elements (4) have a full cross section.

29. Reticular structure according to any one of the preceding claims, wherein the ratio between the distance between the two adjacent first elements and the distance between two adjacent second elements is between 0,5 and 2, optionally between 0,8 and 1,2.

30. Reticular structure according to any one of the preceding claims, wherein the two first elements immediately adjacent with respect to a direction orthogonal to the development trajectory of at least one of said adjacent first elements are placed at a minimum distance the one with respect to the other between 5 mm and 70 mm, optionally 10 mm and 25 mm.In a 53rd aspect according to any one of the preceding aspects two second elements immediately adjacent with respect to a direction orthogonal to the development trajectory of at least one of said adjacent second elements are placed at a minimum distance the one with respect to the other between 5 mm and 70 mm, optionally 12 mm and 45 mm.

31. Reticular structure according to any one of the preceding claims, wherein the reticular structure (2) comprises quadrilateral meshes, optionally having square or rectangular shape.

32. Reticular structure according to any one of the preceding claims, wherein the reticular structure (2) has a weight by area unit between 3 g / m2and 30 g / m2, optionally between 5 g / m2and 15 g / m2.

33. Turf comprising:a soil layer,a predetermined quantity of grass emerging from a side of the soil layer,at least a reticular structure (2), according to any one of the preceding claims, engaged to the soil layer.

34. Turf according to the preceding claim, wherein the reticular structure (2) engages a root apparatus of said grass and consolidates at least the soil layer of the turf.

35. Turf according to one of the two preceding claims, wherein the soil layer has a thickness greater than 0,5 cm, optionally between 0,65 cm and 2,5 cm.

36. Turf according to one of the three preceding claims, wherein said reticular structure has portions comprised in the thickness of the soil layer.

37. Turf according to one of the four preceding claims, wherein said turf is wound around itself to form a multi-coils roll.

38. Process for the realization of a turf, said process comprises the steps of:laying the reticular structure (2) according to any one of the preceding claims 1 to 32 on a land portion, sowing the soil portion by laying grass seed.

39. Process according to the preceding claim comprising a step of lay soil on the reticular structure itself to cover at least part of the reticular structure (2) with a layer of soil,40. Process according to any one of the two preceding claims comprising a waiting step, optionally comprised between 6 and 12 months, to allow the growth of a turf.

41. Process according to the preceding claim wherein during the growth step of the turf, is provided a step of pre-conditioning the reticular structure (2) in a biologically active environment to initiate a degradation step of the reticular structure (2).

42. Process according to the preceding claim, wherein the step of pre-conditioning the reticular structure (2) comprises at least one of the following sub-steps:maintaining the reticular structure in an environment containing natural or induced microbiological activity, maintaining the reticular structure in an environment with controlled humidity and / or temperature parameters,treating the soil portion and thus the reticular structure with at least one fertilizer, optionally comprising nitrogen, phosphorus and calcium,irrigating the portion of land.

43. Process according to any one of the preceding claims 39 to 42, wherein the turf formed with the process is of the type according to any one of the preceding claims 33 to 37.

44. Process according to any one of the preceding claims 39 to 43, depending on claim 40, wherein after an at least partial turf growth is provided a step of separating the turf from said portion of land, wherein during the separation the reticular structure is too separated from the portion of land.

45. Process according to the preceding claim, wherein the turf provided with the reticular structure is wound around itself to form a roll.

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