EP2172589A1

EP2172589A1 - Synthetic mat and process for the production of said mat

Info

Publication number: EP2172589A1
Application number: EP08425632A
Authority: EP
Inventors: Mario Borri; Adriano Moioli
Original assignee: Ntt Di Adriano Moioli & C Sas
Current assignee: Ntt Di Adriano Moioli & C Sas
Priority date: 2008-09-25
Filing date: 2008-09-25
Publication date: 2010-04-07

Abstract

There is provided a synthetic mat (1) comprising an outer face (1b) suitable to realize the outer surface of said synthetic mat (1), a plurality of bladelike elements (2) made of thermoplastic polymer matrix material, a backing membrane (3) of the bladelike elements (2), also made of thermoplastic polymer matrix material, the bladelike elements (2) being positioned inside a plurality of holes (5) present in the backing membrane (3) and extending along both faces of prevalent extension of said backing membrane (3), and being constrained to the backing membrane (3) by means of heat-sealing performed on the face of the backing membrane (3) opposite the outer face (1b). This mat (1) is totally recyclable.

Description

The present invention relates to a synthetic mat, in particular a synthetic grass mat, and a process for the production thereof, of the type specified in the preamble of the independent claims.
There are currently known different types of synthetic mats and in particular synthetic grass mats.
In particular, synthetic grass mats are produced to replace expanses of natural grass on playing fields, parks and the like.
These are commonly composed of elements, at least partly bladelike, made of polymer material which simulate, for example, blades of grass, secured to a backing preferably realized by a synthetic fabric with appropriate strength.
Securing of the at least partly bladelike elements to the underlying backing preferably takes place by means of a further layer of adhesive, generally made of rubber latex, which is spread on the opposite face to the exposed surface of the mat.
Synthetic mats, in particular synthetic grass mats for playing fields, are subjected to considerable wear and periodically restored through replacement.
The aforesaid prior art presents some important drawbacks.
In fact, prior art synthetic mats are difficult to dispose of after their replacement. This difficulty is above all due to the presence of components of different kinds which are not recyclable.
Moreover, said adhesive is preferably oven dried: this causes considerable energy consumption and potentially polluting atmospheric emissions.
Said difficulty in disposal is present in all facilities with synthetic mats, and consequently their replacement translates into an increase in the handling costs of this synthetic mat.
In this situation, the technical aim underlying the present invention is to devise a synthetic mat capable of substantially overcoming the aforesaid drawbacks.
Within said technical aim, it is an important object of the invention to obtain a synthetic mat that is easily recyclable in the same processing or easily disposed of.
Another important aim of the invention is to produce a simple and inexpensive synthetic mat.
The technical aim and the objects specified are achieved by a synthetic mat and by a process for the production thereof as claimed in the appended independent claims.
Preferred embodiments are described in the subclaims.
Further characteristics and advantages of the invention are better explained below by the detailed description of a preferred embodiment of the invention, with reference to the accompanying drawings, wherein:

Fig. 1 schematically shows a synthetic mat according to the invention; and
Fig. 2 schematizes the process for the production of the synthetic mat according to the invention.

With reference to the aforesaid Figures, the synthetic mat according to the invention is indicated as a whole with the number 1.
It extends prevalently along a surface 1a, preferably flat when installed, and comprises, parallel to the surface 1a, an outer face 1b, suitable to realize the walking or outer surface of the mat 1, and an inner face 1c, suitable to face the ground or other backings when installed.
The synthetic mat 1 comprises, briefly, a plurality of bladelike elements 2, a backing membrane or sheet 3 for these bladelike elements 2 and, preferably, a membrane or sheet 4 for joining the bladelike elements 2 to the backing membrane 3.
In particular, the bladelike elements 2 pass through at least a pair of holes 5, provided or resulting from the weaving operation, present in the backing membrane 3.
The arrangement of the bladelike elements 2 takes place according to prior art mat weaving techniques. According to this technique, the bladelike elements 2 are bladelike elements or groups of continuous bladelike elements each inserted in a series of holes 5, producing a plurality of reciprocally connected slot-like surface elements. Finally, the upper ends of the slots can be cut to produce a plurality of bladelike surface ends 2a for improved simulation of the pile, of the blades of grass and the like.
Said arrangement causes bladelike surface ends 2a to be produced on each bladelike element 2, which exit from the backing membrane 3 on the outer face 1b and connection portions 2b of each bladelike element 2 which exit from the backing membrane 3 on the opposite face to the bladelike surface ends 2a.
Moreover, the bladelike elements 2 are heat-sealed to the backing membrane 3, preferably along the connection portion 2b thereof disposed on the opposite face of the backing membrane 3 with respect to the bladelike surface ends 2a.
The joining membrane 4 is disposed parallel to the backing membrane 3 and to the surface 1a, and is also heat-sealed to this backing membrane 3, on the side of the inner face 1c of the synthetic mat 1.
The bladelike elements 2, the backing membrane 3 and the joining membrane 4 are made of a thermoplastic polymer matrix material. The term polymer is also intended as thermoplastic rubbers.
Said elements can therefore be made of thermoplastic polymer materials or of composite materials having a thermoplastic polymer matrix and charges, powders or fibres of different materials. Said charges or fibres are appropriately present in quantities that do not affect the recyclability of the materials.
Moreover, the bladelike elements 2, the backing membrane 3 and the joining membrane 4 are made of reciprocally heat-sealable polymer matrix materials, more preferably said matrices are made of polymers belonging to the same family of polymers and even more preferably said matrices are made of the same polymer.
In particular, polyethylenes and polypropylenes are preferably used due to their chemical resistance and to their low environmental impact.
Individually, the bladelike elements 2 have a height that varies according to use, in particular for football fields the length of the bladelike surface ends 2a is preferably between 1 cm and 5 cm.
The backing membrane 3 is preferable made of polymer matrix material charged with powders, fibres or glass fabrics or meshes or the like. The thickness of the membrane is variable and preferably between 0.2 cm and 3 cm.
The joining membrane 4 is instead suitable to give consistency to the mat 1 and to block the bladelike elements 2 with greater efficacy. It also has a thickness preferably between 0.2 and 3 cm and is preferably made of polymer matrix material charged with powders, fibres or glass fabrics or meshes or the like.
The structure can also be provided with parts made of foamed polymer to modify the physical properties thereof as required.
The invention comprises a new process 10 for the production of a synthetic mat 1, and in particular of a synthetic mat 1 as described above.
It includes a step 11 to produce the backing membrane 3, described.
This production step 11 preferably takes place using technologies for processing polymer materials of known type, such as: flat head extrusion, calendering, thermo-coating.
This step can also include the production of holes 5 by means of specific punches with established pitch.
The process 10 also comprises a step 12 to weave the bladelike elements 2 on the backing membrane 3 according to the arrangement previously described and illustrated.
Said weaving step 12 takes place by means of needle machines of known type, and on backing membranes 3, which insert the bladelike elements 2 into the backing membrane 3 producing holes 5, or insert them into holes 5 already present on the backing membrane 3.
This is followed by a step 13 to seal the bladelike elements 2 to the backing membrane 3.
In particular, this sealing is a heat-sealing that takes place along the portion of the bladelike elements 2 disposed on the face of the membrane 3 positioned against the inner face 1c of the mat 1. More in particular, it includes heat-sealing of the connection portion 2b of the bladelike element 2 to the backing membrane 3.
Said heat-sealing is appropriately obtained through at least partial melting both of part of the bladelike elements 2 and of the backing membrane 3.
In this sealing step 13 it is important to avoid deformation, through excessive heating, of the bladelike surface ends 2a of the bladelike elements 2 and of the backing membrane 3.
It is therefore appropriate to produce the heat required for heat-sealing by means of sources of heat prevalently with surface effect, i.e. acting only on the surface. These sources of heat are, for example, realized by bars with recirculating hot air, gas plates, singeing with infrared sources, directed laser beams.
It is also appropriate to maintain the face of the membrane 3 positioned against the outer face 1 b of the mat 1 and the bladelike surface ends 2a of the bladelike elements 2 cool. This cooling can take place by insufflating cold air on this surface, by feeding it over perforated tables or cylinders, or the like.
The process 10 also preferably comprises a step 14 to apply the joining membrane 4.
Said application step 14 can combine in a single pass the steps of producing the joining membrane 4 and of joining it through heat-sealing to the backing membrane 3 including the heat-sealed bladelike elements 2.
In this case, said application step preferably takes place through direct thermal coating, in particular by extrusion of a layer of polymer material in molten state onto the backing membrane 3.
Alternatively, the joining membrane 4 is produced separately and subsequently heat-sealed by means of sources of heat prevalently with surface effect, similar to those described previously.
The invention achieves important advantages.
In fact, the mat 1 is structured in an manner suitable to be produced entirely by means of thermoplastic polymers. It is therefore economically and totally recyclable, also with regard to processing off-cuts.
In fact, it is unnecessary to disassemble it into different parts, in particular to separate the bladelike elements 2 from the membranes 3 and 4, in order to recycle it.
The handling costs of this mat are therefore greatly reduced and the environmental impact is very low or substantially non-existent.
In particular, said mat 1 has no adhesive dried in ovens, which causes considerable energy consumption and polluting atmospheric emissions.
These advantages are particularly important if mats 1 for playing fields, and in particular for football fields, are considered. In fact, these mats are subject to considerable wear and require to be replaced frequently.
Moreover, the mat 1 is very simple and inexpensive. It can also be adapted to surfaces of different shapes, as being produced in thermoplastic material it is thermally deformable.
The invention is susceptible to variants falling within the inventive concept. All details can be replaced by equivalent elements, the shapes and dimensions can be any.

Claims

Synthetic mat (1) comprising an outer face (1b) suitable to realize the outer surface of said synthetic mat (1), a plurality of bladelike elements (2), a backing membrane (3) of said bladelike elements (2), presenting a plurality of holes (5), said bladelike elements (2) passing through said plurality of holes (5), characterized in that said bladelike elements (2) and said backing membrane (3) are made of thermoplastic polymer matrix materials suitable to be reciprocally heat-sealed, and in that said bladelike elements (2) are constrained to said backing membrane (3) by means of heat-sealing on the face of said backing membrane (3) opposite said outer face (1b).
Synthetic mat (1) as claimed in claim 1, comprising a joining membrane (4) made of thermoplastic polymer matrix material, said joining membrane (4) being constrained to said backing membrane (3) and to part of said bladelike elements (2) on the opposite face to said outer face (1b) by means of heat-sealing.
Synthetic mat (1) as claimed in one or more of the preceding claims, wherein said bladelike elements (2) and said backing membrane (3) are made of thermoplastic polymer matrix material belonging to a same family of polymers.
Synthetic mat (1) as claimed in one or more of the preceding claims, wherein said bladelike elements (2), and said backing membrane (3) and said joining membrane (4) are made of thermoplastic polymer matrix material belonging to a same family of polymers.
Synthetic mat (1) as claimed in one or more of the preceding claims, wherein said backing membrane (3) is made of thermoplastic polymer matrix including charges.
Synthetic mat (1) as claimed in one or more of the preceding claims, wherein said bladelike elements (2), said backing membrane (3) and said joining membrane (4) are made of recyclable materials.
Process (10) for the production of a synthetic mat (1), said synthetic mat (1) comprising an outer face (1b) suitable to realize the outer surface of said synthetic mat (1), a plurality of bladelike elements (2) made of thermoplastic polymer matrix material, a backing membrane (3) made of thermoplastic polymer matrix material, said process (10) being characterized by comprising: a step (12) to weave said bladelike elements (2) on said backing membrane (3), said bladelike elements (2) passing through said backing membrane (3), a step (13) to seal said bladelike elements (2) to said backing membrane (3) by means of heat-sealing on the face of said backing membrane (3) opposite said outer face (1b).
Process (10) as claimed in claim 7, wherein said heat-sealing is performed by means of sources of heat prevalently with surface effect.
Process (10) as claimed in one or more of claims 7 and 8, wherein said sealing step (13) comprises cooling of said outer face (1 b).
Process (10) as claimed in one or more of claims 7, 8 or 9, comprising a step (14) to apply a joining membrane (4), made of thermoplastic polymer matrix material, to said backing membrane (3) and to part of said bladelike elements (2) on the opposite face to said outer face (1 b) by means of heat-sealing.
Process (10) as claimed in claim 10, wherein said application step (14) preferably takes place through extrusion of a layer of molten polymer matrix material onto said backing membrane (3) on the face opposite said outer face (1b).