[0001] 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.
[0002] There are currently known different types of synthetic mats and in particular synthetic
grass mats.
[0003] In particular, synthetic grass mats are produced to replace expanses of natural grass
on playing fields, parks and the like.
[0004] 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.
[0005] 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.
[0006] Synthetic mats, in particular synthetic grass mats for playing fields, are subjected
to considerable wear and periodically restored through replacement.
[0007] The aforesaid prior art presents some important drawbacks.
[0008] 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.
[0009] Moreover, said adhesive is preferably oven dried: this causes considerable energy
consumption and potentially polluting atmospheric emissions.
[0010] 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.
[0011] In this situation, the technical aim underlying the present invention is to devise
a synthetic mat capable of substantially overcoming the aforesaid drawbacks.
[0012] 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.
[0013] Another important aim of the invention is to produce a simple and inexpensive synthetic
mat.
[0014] 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.
[0015] Preferred embodiments are described in the subclaims.
[0016] 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.
[0017] With reference to the aforesaid Figures, the synthetic mat according to the invention
is indicated as a whole with the number
1.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] In particular, polyethylenes and polypropylenes are preferably used due to their
chemical resistance and to their low environmental impact.
[0029] 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.
[0030] 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.
[0031] 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.
[0032] The structure can also be provided with parts made of foamed polymer to modify the
physical properties thereof as required.
[0033] 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.
[0034] It includes a step
11 to produce the backing membrane 3, described.
[0035] This production step 11 preferably takes place using technologies for processing
polymer materials of known type, such as: flat head extrusion, calendering, thermo-coating.
[0036] This step can also include the production of holes 5 by means of specific punches
with established pitch.
[0037] 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.
[0038] 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.
[0039] This is followed by a step
13 to seal the bladelike elements 2 to the backing membrane 3.
[0040] 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.
[0041] 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.
[0042] 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.
[0043] 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.
[0044] 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.
[0045] The process 10 also preferably comprises a step
14 to apply the joining membrane 4.
[0046] 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.
[0047] 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.
[0048] 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.
[0049] The invention achieves important advantages.
[0050] 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.
[0051] 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.
[0052] The handling costs of this mat are therefore greatly reduced and the environmental
impact is very low or substantially non-existent.
[0053] In particular, said mat 1 has no adhesive dried in ovens, which causes considerable
energy consumption and polluting atmospheric emissions.
[0054] 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.
[0055] 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.
[0056] 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.
1. 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).
2. 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.
3. 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.
4. 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.
5. 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.
6. 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.
7. 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).
8. Process (10) as claimed in claim 7, wherein said heat-sealing is performed by means
of sources of heat prevalently with surface effect.
9. 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).
10. 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.
11. 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).