Apparatus and method for manufacturing reticular bodies made of composite material

DESCRIPTION

The present invention regards an apparatus and method for manufacturing reticular bodies, such as grids or meshes, made of composite material. In particular, the grids regard rigid or semi ^¬ rigid structures, while meshes regard flexible structures, in particular flexible exceeding the main extension plane. For example, the apparatus and the process apply to the manufacturing of grids or meshes or other reticular-structured bodies where the characteristics of lightness, mechanical resistance and resistance against environmental corrosion are required. The reticular bodies, in particular the grids, obtained thanks to the present invention for example apply to composite structures for treadable planes such as walkways, stairs, parapets, hopper openings covers, or for windows, or for obtaining enclosures, gates, or for forming structural elements that can be used for the civil construction industry. The meshes can be used in the geo-technical industry, in particular for consolidation or limitation of structures or soils.

The method and apparatus according to the invention use composite materials for example made of synthetic resin (or thermoplastic or thermosetting polymer matrix) reinforced with synthetic fibres such as carbon fibre, glass fibre, aramid fibre, Kevlar, boron fibre or using natural fibres such as natural fibres of animal origin, basalt fibres or natural fibres of plant origin.

As known, the grids currently available in the market normally consist of a series of first elongated elements and a series of second elongated elements fixed transversely to the first elongated elements so as to define a grid structure.

For example, there are known structures made of composite material consisting of parallel bars connected to each other with profiles glued or connected transversely to the parallel bars. The bars and profiles can for example be obtained by means of pultrusion: then, with the aim of obtaining the grid, there requires an operation for coupling the bars with said transversal profiles.

Reticular bodies made of composite material may alternatively be obtained by moulding in special mould or formworks . In particular, the reinforcement fibres are placed in the mould and then synthetic resin is introduced into the mould at liquid state: the liquid resin is absorbed by the layers made of reinforcement fibre and it fills the mould cavity. The moulding operation is optionally obtained by placing reinforcement fibres pre-impregnated with synthetic resin into the mould. After a chemical and/or thermal resin solidification process, there follows the removal of the grid, which appears as a monolithic body made of composite material, from the mould.

The moulded grids described above reveal drawbacks in terms of consumption of material, weight of the finished product, difficulty when it comes to removing the product from the mould, etcetera.

In order to overcome these drawbacks, there was developed a solution subject of PCT patent application n° PCT/IT2015/000120 in which a method is proposed for moulding a product made of composite material shaped in a grid-like manner wherein the particular shape of the cross-section of the transversal section of the elongated elements forming the grid enabled to minimise the consumption of material while simultaneously guaranteeing optimal mechanical resistance of the obtained product.

Though the solutions described above enabled obtaining good quality grids made of composite material, the apparatus and production process currently available revealed room for further improvement.

SUMMARY OF THE INVENTION

In particular an object of the invention is to provide an apparatus and a process for manufacturing grids made of composite material capable of enabling better production yield. A further object of the invention is to enable the manufacturing of grids made of composite material with good quality and mechanical characteristics, without jeopardising the simplicity of the apparatus and production process.

A further object of the invention is to guarantee the formation of grids with uniform thrust, without waste of synthetic resin and/or reinforcement fibre.

Furthermore, an object of the invention is to provide a process for manufacturing grids made of composite material by means of an apparatus that enables higher production volumes with respect to systems currently in use.

These and other objects are substantially attained by an apparatus and by a method according to one or more of the attached claims.

A 1 ^st aspect regards an equipment (100) for manufacturing reticular- structured bodies (1), particularly grids or meshes, made of reinforced synthetic resin, comprising at least one conveyor (2) having an operative side defining at least one reticular-shaped forming cavity (3) .

A 2 ^nd aspect, optionally according to the 1 ^st aspect, regards an apparatus (100) for manufacturing reticular-structured bodies (1), particularly grids or meshes, made of reinforced synthetic resin, comprising at least one depositing device (4) configured for performing one or more of the following operations: positioning a dry reinforcement fibre (5) inside said forming cavity (3), positioning the synthetic resin (6) at liquid state on the reinforcement fibre (5), particularly inside said forming cavity ( 3 ) , positioning the reinforcement fibre (5) pre-impregnated with the synthetic resin (6) inside said forming cavity (3), enabling, in use, to form a continuous artifact (7) made of composite material inside said forming cavity.

A 3 ^rd aspect, optionally according to any one of the preceding aspects, regards an apparatus (100) for manufacturing reticular- structured bodies (1), particularly grids or meshes, made of reinforced synthetic resin, comprising at least one station (8) for separating the continuous artifact (7) from the conveyor (2) .

In a 4th aspect according to any one of the preceding aspects, the conveyor (2) comprises, or consists of a conveyor belt arranged as a closed-loop, said conveyor (2) further comprising: an upper segment (2a) , a lower segment (2b) , and at least two juxtaposed joining segments (2c, 2d) between ends of the upper segment (2a) and of the lower segment (2b) .

In a 5 ^th aspect according to the preceding aspect, the forming cavity (3) is defined at least at the upper segment (2a) .

In a 6 ^th aspect according to any one of the preceding aspects, said conveyor (2) in turn comprises:

• a continuous base body (9), and

• a plurality of elements (10) projecting from said base body (9) and configured for defining, on the operative side of the conveyor (2), a first series of channels (11) and a second series of channels (12) transversal to the channels of the first series (11), the channels of the first series (11) intersecting the channels of the second series (12) at a plurality of crossing areas (13) .

In a 7 ^th aspect according to the preceding aspect, the channels of the first series (11) are parallel to each other and the channels of the second series (12) are parallel to each other and orthogonal to the channels of the first series (11) . In an 8 ^th aspect according to aspect 6 or 7, the base body (9) is arranged in a plane at at least the upper segment (2a) of the conveyor belt (2), said first and said second channels (11, 12) constantly defining said reticular-shaped forming cavity (3) at the upper segment (2a) of the conveyor belt (2) .

In a 9 ^th aspect according to any one of aspects 4 to 8, the upper segment (2a) of the conveyor (2) can be driven to confer a corresponding motion of said first and second channels (11, 12) along a pre-set advancement direction (A) of the operative path.

In a 10 ^th aspect according to any one of aspects 6 to 9, the projecting elements (10) are equal to each other and have: a first portion (10a) emerging from the base body (9), and a second portion (10b), consecutive to the first portion (10a) and having an axial and a radial overall dimension respectively smaller than the axial and radial overall dimension of the first portion (10a) .

In an 11 ^th aspect according to any one of aspects 6 to 10, said projecting elements (10) conferring to the first channels (11) a cross-section (14), extending along a direction perpendicular to a main extension direction of the first channels (11), having a first elongated-shaped part (14a) moving apart from the base body (9) and a second part (14b) transversal to the first part (14a) .

In a 12th aspect according to any one of aspects 6 to 11, said projecting elements (10) conferring to the second channels (12) a respective cross-section (15), extending along a direction perpendicular to a main extension direction of the second channels (12), having a first elongated-shaped part (15a) moving apart from the base body (9) and a second part (15b) transversal to the first part (15a) .

In a 13 ^th aspect according to any one of aspects 11 or 12, the cross- section (14) of the first channels (11) and/or the cross-section (15) of the second channels (12) has the rectangular or trapezoidal- shaped first parts (14a, 15a) with smaller base facing towards the base body ( 9 ) .

In a 14 ^th aspect according to any one of aspects 11 to 13, the second part (14b, 15b) projects transversely with respect to the first part (14a, 15a) on both sides of the latter.

In a 15 ^th aspect according to any one of aspects 11 to 14, the cross- section (14) of the first channels (11) and/or the cross-section

(15) of the second channels (12) is substantially T-shaped.

In a 16th aspect according to any one of the preceding aspects, the conveyor (2), at the operative side thereof, has a contact surface

(16) designated to contactingly receive said fibre (5) and/or said synthetic resin (6) from the deposing device (4), such contact surface (16) comprising at least one continuous non-stick layer (17), preferably an outer non-stick layer.

In a 17 ^th aspect according to the preceding aspect, the continuous non-stick layer (17) coats, without interruption, the projecting elements (10) and the segments of the base body (9) interposed between said projecting elements (10), the forming cavity (3) being completely coated by the continuous non-stick layer (17) .

In an 18 ^th aspect according to aspects 16 or 17, the non-stick layer

(17) is a continuous layer comprising at least one among:

- a silicone-based material,

- polytetrafluoroethylene (PTFE) ,

- polyvinyl alcohol (PVA) .

In a 19 ^th aspect according to any one of the preceding aspects, the apparatus (100) comprises at least one actuation device (18), optionally an electric motor, configured to drive said conveyor (2) in motion.

In a 20 ^th aspect according to the preceding aspect, the apparatus comprises a control unit (50), active on the actuation device (18) and configured for controlling such actuation device (18) by driving the conveyor (2) with a continuous motion so that subsequent portions of the forming cavity (3) are also continuously driven from upstream towards downstream along the advancement direction (A) of the operative path.

In a 21 ^st aspect according to any one of the preceding aspects, the conveyor (2) and/or the plurality of projecting elements (10) comprise a heater (19) configured to define a predefined temperature at least at the upper segment (2a) of the conveyor (2) or of the plurality of the projecting elements (10) .

In a 22 ^nd aspect according to the preceding aspect, the heater (19) comprises one or more electrical resistors positioned along the conveyor (2), particularly at the plurality of projecting elements (19), said resistors being configured so that the flow of a predetermined electric current through the latter caused by a predetermined electric potential difference defines a heat source.

In a 23 ^rd aspect according to aspect 21 or 22, the heater (19) is configured to define a temperature profile at least along the upper segment (2a) of the conveyor (2), particularly at the plurality of the projecting elements (10) .

In a 24 ^th aspect according to any one of the preceding aspects, the apparatus (100) comprises at least one temperature sensor configured to emit a temperature monitoring signal at one or more points of the conveyor (2) and/or projecting elements (10) .

In a 25 ^th aspect according to the preceding aspect, said temperature sensor is connected to a control unit (50) is configured to:

- receive - in input - a value of a predetermined temperature or a temperature profile along the conveyor belt (2),

- receive - in input - the temperature monitoring signal from the temperature sensor,

- compare the predefined temperature value or profile along the conveyor (2) with the corresponding temperature monitoring signal, - adjust at least one parameter for controlling the heater (19) so as to minimise the difference between the predetermined temperature or temperature profile along the conveyor belt with the corresponding temperature monitoring signal.

In a 26 ^th aspect according to any one of the preceding aspects, the apparatus (100) comprises at least one station (20) for the solidification of the synthetic resin (6), active at the operative side of the conveyor (2) .

In a 27 ^th aspect according to the preceding aspect, said solidification station (20) is arranged downstream of the depositing device (4) with respect to the advancement direction (A) of the upper segment (2a) of the conveyor (2) .

In a 28 ^th aspect according to aspects 26 or 27, such solidification station (20) is configured to enable an at least partial solidification of the synthetic resin (6) present in the forming cavity (3) and define, downstream of the solidification station (20), a reticular-structured continuous artifact (7) positioned inside the forming cavity (3) .

In a 29 ^th aspect according to any one of aspects 26 to 28, the solidification station (20) comprises at least one actinic radiation source, optionally comprising one or more ultraviolet lamps, configured to emit a radiation directed towards said upper segment (2a) of the conveyor (2) and affecting the whole width of the conveyor ( 2 ) .

In a 30 ^th aspect according to any one of aspects 26 to 29, the solidification station (20) comprises at least one thermal source directed towards said upper segment (2a) of the conveyor (2) and affecting the whole width of the conveyor (2) .

In a 31 ^st aspect according to any one of aspects 25 to 30, the control unit (50) is configured to adjust at least one actinic radiation source emission parameter, in particular the actinic radiation intensity as a function of a conveyor speed parameter, optionally as a function of the speed set to or the detected speed of the conveyor ( 2 ) .

In a 32 ^nd aspect according to any one of aspects 25 to 31, the control unit (50) is configured to adjust at least one thermal source emission parameter, in particular the thermal source intensity as a function of a conveyor speed parameter, optionally as a function of the speed set to or the detected speed of the conveyor (2) .

In a 33 ^rd aspect according to any one of aspects 26 to 32, the separation station (8) operates downstream of the solidification station (20) .

In a 34 ^th aspect according to any one of aspects 26 to 33, the separation station (8) comprises at least one guide member, optionally comprising one or more rollers and/or one or more conveyor belts, configured for engaging a portion of the continuous artifact (7) exiting the solidification station (20) and for conferring it a trajectory suitable to cause a removal of the continuous artifact from the forming cavity (3) and a separation of the continuous artifact (7) from the conveyor (2) .

In a 35 ^th aspect according to any one of the preceding aspects, the depositing device (4) comprises at least one element, for example a spool (21) for supplying a fibre or one or more sets of fibres of the reinforcement material (5) , at least one impregnation station (22) designated to receive the fibre or set of fibres (5) from the supplying spool (21) and impregnate them with a predetermined amount of resin ( 6 ) .

In a 36 ^th aspect according to any one of the preceding aspects, the depositing device (4) comprises a respective fibre guide member (23) arranged between the impregnation station (22) and the conveyor (2) and configured to guide a deposition of said fibre or said fibres previously impregnated in the first and/or second channels (11, 12) .

In a 37 ^th aspect according to aspects 35 or 36, the impregnation station (22) comprises at least one injection nozzle (24) positioned and configured to introduce synthetic resin into said forming cavity (3) and a synthetic resin supplying device (6) connected to the injection nozzle (24) and configured to supply synthetic resin (6) to the injection nozzle (24) at liquid state.

In a 38 ^th aspect according to any one of aspects 25 to 37, the control unit (50) is configured to adjust at least one operative parameter of the depositing device, in particular a mass amount of fibre (5) deposited inside the forming cavity per time unit as a function of a speed parameter of the conveyor (2), optionally as a function of the speed set to, or the detected speed of the conveyor (2) .

In a 39 ^th aspect according to any one of aspects 25 to 38, the control unit (50) is configured to adjust at least one operative parameter of the depositing device, in particular an amount of synthetic resin

(6) deposited over the time unit inside the forming cavity (3) as a function of a speed parameter of the conveyor (2), optionally as a function of the speed set to, or the detected speed of the conveyor

(2) .

In a 40 ^th aspect according to any one of the preceding aspects, the apparatus (100) comprises an adjustment squeegee blade (25) active at the operative side of the conveyor (2) and downstream of the depositing device (4), said squeegee blade (25) extending transversally above the operative side of the conveyor (2) to remove possible surplus resin (6) and for defining a semi-finished product having a controlled thickness.

In a 41 ^st aspect according to any one of the preceding aspects, the control unit (50) is configured to adjust at least one distance between the lower active edge of said squeegee blade (25) and the conveyor (2) as a function of the speed parameter of the conveyor (2), optionally as a function of the speed set to, or the detected speed of the conveyor (2) .

In a 42 ^nd aspect according to any one of the preceding aspects, the apparatus comprises a cutting station (26) configured to cut the continuous artifact (7) transversally to the/an advancement direction (A) thereof to define, starting from said continuous artifact (7), a plurality of reticular bodies (1) separated from each other.

In a 43 ^rd aspect according to the preceding aspect, the cutting station (26) comprises at least one among: a reciprocating motion rotating blade, a water cutting system, a laser cutting system, a shearing machine.

In a 44 ^th aspect according to aspects 42 and 43, the control unit (50) is configured to: receive - in input - a signal representing a desired length of the reticular bodies, control the sequence of the operations of the cutting station (26) as a function of the speed parameter of the conveyor (2), optionally as a function of the speed set to, or the detected speed of the conveyor ( 2 ) .

In a 45 ^th aspect according to any one of the preceding aspects, the apparatus (100) comprises an operative condition in which said apparatus (100) is configured to obtain continuous artifacts (7) and/or reticular-structured single bodies (1) .

In a 46 ^th aspect according to any one of the preceding aspects, the apparatus (100) comprises an inoperative condition in which said apparatus (100) is inactive.

In a 47 ^th aspect according to any one of aspects 6 to 46, the projecting elements (10) have an engagement system (27) configured to constrain the projecting elements (10) to the base-body (9) of the conveyor (2) .

In a 48 ^th aspect according to any one of aspects 6 to 47, the engagement system is configured to: define a stable constraint between the projecting elements (10) and the base body (9) of the conveyor (2) during the operative condition, define a removable constraint between the projecting elements (10) and the base body (9) of the conveyor (2) during the inoperative condition so as to enable the replacement and/or modification of the position of the projecting elements (10) .

A 49 ^th aspect regards a plant (200) for manufacturing reticular- structured bodies, in particular grids or meshes, comprising at least one first apparatus (100) of the type according to any one of the preceding aspects 1 to 48 and configured to form a first grid (30) .

In a 50 ^th aspect according to the preceding aspect, the plant (200) comprises at least one assembling station (28) configured to receive a second grid (31) and couple it to the first grid (30) so as to obtain a single body (29) comprising the first and second grid (30, 31) coupled to each other.

In a 51 ^st aspect according to aspects 49 or 50, the plant (200) comprises a second apparatus (100) of the type according to any one of the preceding aspects 1 to 48 configured to obtain the second grid ( 31 ) .

In a 52 ^nd aspect according to aspects 50 or 51, the assembling station (28) comprises at least one glue distributor configured to apply a gluing material (32) to at least one of said first and said second grid (30, 31) and a guide system for guiding and arranging the first and second grid (30, 31) adjacent to each other.

In a 53 ^rd aspect according to any one of aspects 49 to 52, the first apparatus (100) is configured to obtain a first grid (30) and it comprises a first conveyor (2) with a forming cavity having first channels (11) spaced from each other by a pitch (PI) and second channels (12) spaced from each other by a pitch (P2) .

In a 54 ^th aspect according to any one of aspects 49 to 53, the second apparatus is configured to obtain a second grid (31) and it comprises a second conveyor with a forming cavity (3) having first channels (11) spaced from each other by a pitch (P10) and second channels

(12) spaced from each other by a pitch (P20) .

In a 55 ^th aspect according to aspects 53 or 54, the pitch (PI) of the first channels (11) of the forming cavity of the first conveyor (2) is greater than, preferably multiple of the pitch (P10) of the first channels (11) of the forming cavity (3) of the second conveyor, while the pitch (P2) of the second channels (12) of the forming cavity (3) of the first conveyor (2) is greater than, preferably multiple of the pitch (P20) of the second channels (12) of the forming cavity (3) of the second conveyor.

In a 56 ^th aspect according to any one of aspects 49 to 55, the plant (200) provides for a cutting station (26) configured to cut the continuous artifact (7) transversally to the/an advancement direction (A) thereof to define, starting from said continuous artifact (7), a plurality of reticular bodies (1) separated from each other.

A 57 ^th aspect regards a method for manufacturing reticular-structured bodies (1), in particular grids or meshes, made of reinforced synthetic resin, comprising displacing at least one reticular-shaped forming cavity (3) along a pre-set operative path.

In a 58 ^th aspect according to the preceding aspect, the manufacturing method comprises performing a depositing step comprising one or more of the following operations: positioning a dry reinforcement fibre (5) inside said forming cavity (3),

positioning a synthetic resin (6) at liquid state at contact with the reinforcement fibre (5), particularly inside said forming cavity (3),

positioning the reinforcement fibre (5) pre-impregnated with the synthetic resin (6) inside said forming cavity (3) . In a 59 ^th aspect according to aspects 57 or 58, the manufacturing method comprises forming, inside the forming cavity (3), at least one portion of a continuous artifact (7) made of composite material.

In a 60 ^th aspect according to aspects 57 or 58 or 59, the manufacturing method comprises removing said portion of the continuous artifact (7) from the forming cavity (3) .

In a 61 ^st aspect according to any one of aspects 57 to 60, the step of displacing the forming cavity (3) provides for the use of a conveyor (2) arranged as closed loop conferring a motion to the forming cavity (3) along a pre-set operative path.

In a 62 ^nd aspect according to any one of aspects 57 to 61, the method comprises a solidification step to enable an at least partial solidification of the synthetic resin (6) present in the forming cavity (3), particularly at the upper segment (2a) of the conveyor (2), to define a reticular-structured continuous artifact.

In a 63 ^rd aspect according to the preceding aspect, the solidification step comprises the step of emitting an actinic radiation, optionally by means of ultraviolet lamps, towards the upper segment of the conveyor (2) affecting the whole width of the latter.

In a 64 ^th aspect according to aspects 62 or 63, the solidification step comprises the step of providing a thermal source directed towards or at the upper segment (2a) of the conveyor (2), particularly at the forming cavity (3), affecting the whole width of the latter.

In a 65 ^th aspect according to any one of aspects 62 to 64, the manufacturing method comprises a step of removing the continuous artifact (7) following the solidification step, to remove said continuous artifact (7) from the forming cavity (3) downstream of the conveyor (2) by means of a guide member, optionally by means of one or more rollers or several conveyor belts.

In a 66 ^th aspect according to any one of aspects 58 and 65, the depositing step comprises the step of supplying a fibre or a set of fibres of a reinforcement material (5), for example by means of a spool (21), to the conveyor (2) .

In a 67 ^th aspect according to any one of aspects 58 to 66, the depositing step comprises guiding, upstream of the conveyor (2) and by means of a guide member, the fibre or the set of reinforcement fibres in the first and second channels (11, 12) defining the forming cavity (3) according to a predefined weaving scheme.

In a 68 ^th aspect according to any one of aspects 58 to 67, the depositing step comprises the step of impregnating the reinforcement fibres (5) with a predetermined amount of synthetic resin (6) at liquid state.

In a 69 ^th aspect according to any one of aspects 58 to 68, the depositing step comprises the step of injecting a predetermined amount of synthetic resin (6) at liquid state into one or more of the forming cavities (3) by means of an injection nozzle (24) .

In a 70 ^th aspect according to any one of aspects 58 to 69, the depositing step comprises monitoring a mass amount of the reinforcement fibre (5) deposited in the forming cavity (3) .

In a 71 ^st aspect according to any one of aspects 58 to 70, the depositing step comprises monitoring an amount of the synthetic resin (6) deposited over the time unit in the forming cavity (3) .

In a 72 ^nd aspect according to any one of aspects 58 to 71, the depositing step comprises adjusting, by means of a control unit (50), the supplied mass amount of fibre (5) and/or the amount of synthetic resin (6) as a function of a parameter representing the speed set to, or the detected speed of the conveyor (2) .

In a 73 ^rd aspect according to any one of aspects 57 to 72, the method comprises the step of removing possible surplus resin (6) by using an arranged squeegee blade (25) , wherein said step occurs after the step of impregnating and/or injecting the synthetic resin (6) onto the reinforcement fibres (5) . In a 74 ^th aspect according to any one of aspects 57 to 73, the method comprises the step of monitoring a distance between an active lower edge of the squeegee blade (25) and the conveyor (2), particularly between an active lower edge of the squeegee blade (25) and at least one projecting element.

In a 75 ^th aspect according to the preceding aspect, the method comprises the step of adjusting, by means of a control unit (50), said distance as a function of at least one from the group among: a parameter representing the speed set to, or the detected speed of the conveyor (2), a parameter representing the predetermined amount of synthetic resin (6) supplied during the impregnation and/or injection step .

In a 76 ^th aspect according to any one of aspects 57 to 75, the manufacturing method comprises step of cutting the continuous artifact (7) transversally to the advancement direction (A) thereof, after the step of removing the portion of the continuous artifact (7) from the forming cavity (3) .

In a 77 ^th aspect, the method for manufacturing reticular-structured bodies (1), in particular grids, made of reinforced synthetic resin according to any one of aspects 57 to 76, occurs by using an apparatus (100) according to any one of aspects 1 to 48.

In a 78 ^th aspect, the method for manufacturing reticular-structured bodies (1), in particular grids, made of reinforced synthetic resin according to any one of aspects 57 to 77, occurs by using a plant (200) according to any one of aspects 49 to 56, said method comprising obtaining a first grid (30) by using an apparatus (100) according to any one of aspects 1 to 48.

In a 79 ^th aspect, the method for manufacturing reticular-structured bodies (1), in particular grids, made of reinforced synthetic resin according to any one of aspects 57 to 78, occurs by using a plant (200) according to any one of aspects 49 to 56, said method comprising obtaining a second grid (31) .

In an 80 ^th aspect according to aspects 78 or 79, the manufacturing method comprises coupling said first and second grid (30, 31) to define a single body (29) .

In an 81 ^st aspect according to the preceding aspect, the step of coupling the first and second grid (30, 31) comprises at least one step from the group among: applying at least one gluing material (32) to the first and/or second grid (30, 31) , arranging the first and second grid (30, 31) adjacent to each other, particularly along the main extension plane, so as to define a mutual gluing .

In an 82 ^nd aspect according to any one of aspects 78 to 81, the step of obtaining the second grid (31) is optionally performed by using an apparatus (100) according to any one of aspects 1 to 48.

In an 83 ^rd aspect according to any one of aspects 78 to 82, the manufacturing method comprises a step of cutting the reticular- structured single body (29) transversally to the/an advancement direction (A) thereof to define a plurality of reticular-structured single bodies (29) .

An 84 ^th aspect regards a reticular-structured continuous artifact (7) comprising : a plurality of longitudinal elements (58), a plurality of transversal elements (59) integrally joined to the longitudinal elements (58).

In an 85 ^th aspect according to the preceding aspect, the continuous artifact (7) is obtained by means of an apparatus (100) according to any one of aspects 1 to 48. In an 86 ^th aspect according to aspect 84 or 85, the continuous artifact (7) is obtained by means of a plant (200) according to any one of aspects 49 to 56.

In an 87 ^th aspect according to aspect 84 or 85 or 86, the continuous artifact (7) is obtained by means of a method according to any one of aspects 57 to 83.

In an 88 ^th aspect according to any one of aspects 84 to 87, said longitudinal elements extend parallel to an advancement direction A.

An 89 ^th aspect regards reticular-structured body (1), particularly a grid or a mesh, comprising a reticular-structured discrete body having : a plurality of longitudinal elements (60), a plurality of transversal elements (61) integrally joined to the longitudinal elements (60).

In a 90 ^th aspect according to the preceding aspect, the discrete body is obtained by means of an apparatus (100) according to any one of aspects 1 to 48, following an operation for the transversal cutting of the continuous artifact (7) .

In a 91 ^st aspect according to aspect 89 or 90, the discrete body is obtained by means of a plant (200) according to any one of aspects 49 to 56, following an operation for the transversal cutting of the continuous artifact (7) .

In an 92 ^nd aspect according to aspect 89 or 90 or 91, the discrete body is obtained by means of a method according to any one of aspects 57 to 83, following an operation for the transversal cutting of the continuous artifact (7) .

In a 93 ^rd aspect according to any one of aspects 1 to 83, the forming cavity (3) of the conveyor (2) is open on the operative side so as to enable direct access to the forming cavity during the deposition step . In a 94 ^th aspect according to the preceding aspect, the solidification station (20) comprises at least one selected from the group among:

- at least one actinic radiation source, for example having one or more ultraviolet lamps, configured to emit a radiation directed towards the operative side of the conveyor (2) and preferably affecting the whole width of the conveyor (2),

- at least one thermal source directed towards the operative side of the conveyor (2) and preferably affecting the whole width of the conveyor ( 2 ) .

In a 95 ^th aspect according to the preceding aspect, the actinic radiation source faces directly towards the open side of the formation cavity and it is configured to emit a radiation that travels in a direct and unobstructed optical path towards the formation cavity.

In a 96 ^th aspect according to any one of aspects 1 to 83 or from 93 to 95, the projecting elements (10) of the conveyor (2) are obtained in a single piece.

In a 97 ^th aspect according to any one of aspects 1 to 83 or from 93 to 96, the projecting elements (10) of the conveyor (2) are obtained in a single piece made of silicone material.

In a 98 ^th aspect according to any one of aspects 1 to 83 or from 93 to 97, the conveyor (2) is conveyor belt fully made of silicone material .

DETAILED DESCRIPTION APPARATUS

Further characteristics and advantages will be apparent from the detailed description of an exemplified - and thus non-limiting - embodiment of an apparatus and a method according to the invention. The detailed description will be carried out with reference to the attached drawings provided solely by way of non-limiting example in which figure 2 is a schematic representation of an apparatus for manufacturing grids, for example elongated, according to the aspects of the invention. With reference to the attached figures, an apparatus for manufacturing grids made of synthetic resin with reinforcement fibres is indicated in its entirety with 100.

The apparatus 100 of figure 2 comprises at least one conveyor 2 (see figure 1) having an operative side defining at least one reticular- shaped forming cavity 3. In particular, the conveyor 2 comprises a conveyor belt arranged as a closed loop, having an upper segment 2a, a lower segment 2b and at least two juxtaposed joining segments 2c, 2d between the ends of the upper segment and the lower segment. In particular, the forming cavity 3 is defined at least at the upper segment 2a. The conveyor 2, in particular the conveyor belt, comprises a continuous base body 9 and a plurality of projecting elements 10. The projecting elements 10 extend moving apart from the base body 9 and they are configured to define, on the operative side of the conveyor, a first series of channels 11 and a second series of channels 12 transversal to the first series. In the preferred embodiment, the channels of the first series 11 are parallel to each other and the channels of the second series 12 are parallel to each other and orthogonal to the channels of the first series 11 intersecting with a plurality of crossing areas 13. Alternatively, the channels of the first and the second series 11, 12 intersect in a non-orthogonal manner to define a rhomboidal or polygonal shape (not shown in the attached figures) . Thus, the first and the second channels 11, 12 define the reticular-shaped forming cavity 3 at the upper segment 2a of the conveyor 2.

The projecting elements 10 are preferably equal to each other and have a first portion 10a, emerging from the base body 9, and a second portion 10b, consecutive to the first portion 10a and having an axial and a radial overall dimension respectively smaller than the axial and radial overall dimension of the first portion 10a. In other words, the first portion 10a emerges from the base body 9 of the conveyor 2 and it has an axial extension, measured starting from the base body 9 and in a direction perpendicular thereto, greater than the axial extension of the second portion 10b. Furthermore, the first portion 10a has a radial extension, in particular a surface having an extension orthogonal to the upper portion of the base body 9 of the conveyor belt 2, greater than the equivalent radial extension of the second portion 10b.

The first channels 11 define a cross-section 14 (see figure la), extending along a direction perpendicular to a main extension direction of the first channels 11, having a first elongated-shaped part 14a moving apart from the base body 9 and a second part 14b transversal to the first part 14a. In a preferred embodiment and similarly to the first channels 11, the second channels 12 define a respective cross-section 15 (see figure 2a), extending along a direction perpendicular to a main extension direction of the second channels 12, having a first elongated-shaped part 15a moving apart from the base body 9 and a second part 15b transversal to the first part 15a. Thus, the cross-section 14, 15 of the first or second channels 11, 12 is substantially T or L-shaped.

In particular, the first part 14a, 15a of the cross-section defined by the first and/or second channels 11, 12 is rectangular or trapezoidal-shaped with the smaller base facing towards the base body 9 while the second part 14b, 15b of the cross-section emerges transversely from the first part 14a, 15a. The second part 14b, 15b may be positioned centrally with respect to the first part 14a, 15a to define, as previously mentioned, a T shape as shown in figures la and 2a. The first part 14a, 15a of the cross-section may alternatively not be centred with respect to the second part 14b, 15b to define a non-symmetrical T shape with respect to an axial direction, while the second part 14b, 15b alternatively has its side shared with the first part 14a, 15a to define an L-shape of the cross-section .

In the preferred embodiment, the first part 14a, 15a of the cross- section 14, 15 defined by the first and/or second channels 11, 12 is trapezoidal-shaped with the smaller base facing towards the base body 9 of the conveyor 2 so as to facilitate the removal of a continuous artifact 7 from the forming cavity 3.

The elongated shape of the first part 14a, 15a enables obtaining a continuous artifact 7 having greater resistance to bending, in particular the particular T or L shape enables to obtain a high bending moment of inertia of the grid as well as a large treadable surface .

In an embodiment, the projecting elements have a system 27 for engaging onto the conveyor 2, the engaging system being of the removable type, so that during the operations for forming the continuous artifact 7, the projecting elements 10 are stably constrained to the conveyor belt 2 maintaining the cross-section 14, 15, defined by the channels of the first and/or second series 11, 12, constant at least at the upper segment 2a of the conveyor 2 and so that - during a shutdown step of the apparatus 100 - the projecting elements 10 can be removed and/or displaced so as to enable replacement thereof or, alternatively, to define a different geometric shape of the first and second channels 11, 12. In particular, modifying the geometric shape of the projecting elements 10 enables obtaining a variation of the geometric features of the cross-section 14, 15 of the channels of the first and/or second series 11, 12. Furthermore, modifying the direction of the projecting elements 10 enables modifying the shape of the reticular structure, in particular the shape of a section of the reticular structure along the main extension plane of the artifact 7. In other words, modifying the direction of the projecting elements enables obtaining rectangular/square-shaped (see figure 3) or rhomboidal/polygonal- shaped (not shown in the attached figures) reticular-structured continuous artifacts 7.

In a further embodiment, the plurality of projecting elements 10 are obtained in a single piece, in particular made of silicone material. In particular, the conveyor belt 2 and the plurality of projecting elements 10 are made of silicone material to form a single piece, without interruption. In said embodiment, the first part 14a, 15a of the cross-section 14, 15 defined by the first and/or second channels 11, 12 is rectangular-shaped, in that the flexibility and deformability of the silicone material enables an easy removal of the semi-finished product from the forming cavity 3: in particular the first parts 14a, 15a of the projecting elements 10 are parallel to each other and perpendicular with respect to the resting surface of the conveyor 2 and/or the set advancement direction.

The conveyor 2 comprises an actuation device 18 configured to drive the base body 9 of the conveyor 2, and thus the projecting elements 10 constrained to the base body 9. In particular, the actuation device 18 is an electric motor controlled by means of a control unit 50 so that subsequent portions of the forming cavity 3 are also moved from upstream towards downstream along an advancement direction A of the operative path. The actuation device 18 may define, in a preferred embodiment, a continuous motion, in particular a motion in which the advancement speed is constant over time, or a discontinuous motion, in which the advancement speed varies over time, in an interval comprised between a null value and a maximum advancement speed value.

The outer surface of the conveyor 2 and/or of the projecting elements 10, in particular the contact surface designated to contactingly receive the reinforcement fibre 5 and the synthetic resin 6, comprises at least one continuous non-stick layer 17, preferably an outer non-stick layer. The continuous non-stick layer 17 coats, without interruption, the projecting elements 10 and/or the base body 9 so that the forming cavity 3 is completely coated by the continuous non-stick layer 17. The non-stick layer 17 is a continuous layer comprising a silicone-based material, optionally a polytetrafluoroethylene (PTFE) or polyvinyl alcohol (PVA) compound.

In a further embodiment, the projecting elements 10 and/or the base body 9 of the conveyor 2 fully or partly consist of non-stick material. For example, the projecting elements 10 and/or the base body 9 of the conveyor 2 can be made of polytetrafluoroethylene (PTFE) . A non-stick layer 17 may alternatively be applied on the projecting elements 10 and/or on the base body 9 of the conveyor 2 by means of a mechanism for dispensing the non-stick material, in particular a nozzle-like dispensing system, spray or immersion system.

The apparatus 100 (see figure 2) comprises at least one depositing device 4 configured to position the dry reinforcement fibre (5) inside said forming cavity 3 and positioning the synthetic resin 6 at liquid state on the reinforcement fibre 5, particularly inside said forming cavity 3, so that the entirety or part of the reinforcement fibres 5 are wet by the synthetic resin 6. The positioning of the synthetic resin 6 at the reinforcement fibre 5 occurs by means of an impregnation station 22. The impregnation station 22 can be positioned upstream of the conveyor 2, in which the resin is dispensed by means of nozzles 24 or by means of immersion of the reinforcement fibre 5 into a vat containing liquid synthetic resin 6. The impregnation station 22 can be alternatively faced to the conveyor 2 (see figure 2), in particular at the upper segment 2a of the conveyor 2, so as to introduce synthetic resin 6 into the forming cavity 3, for example by using a nozzle-like dispensing system 24. The depositing device is alternatively configured to position the reinforcement fibre 5, pre-impregnated with the synthetic resin 6, inside the forming cavity 3.

Thus, the depositing device 4 enables, in use, to form a continuous artifact 7 made of composite material inside the cavity 3.

The composite material of the reinforcement fibre 5 and synthetic resin 6 housed in the forming cavity 3 is configured to undergo a solidification process, during which the synthetic resin 6 transforms its chemical and mechanical properties moving from a liquid state to a solid state, thus conferring greater rigidity to the composite material, in particular greater rigidity against shear and bending, so as to obtain a reticular-structured continuous artifact 7 inside the forming cavity 3. The process for the solidification of the synthetic resin 6 may occur by using a further chemical compound configured to facilitate the polymerisation and/or cross-linking of the synthetic resin 6, or by means of the action of a heat source at a predetermined temperature or by means of the action of an actinic radiation, for example a ultraviolet radiation.

In order to guarantee the solidification of the composite material, the apparatus 100, shown in figure 2, comprises a solidification station 20, the latter comprising at least one selected from the group among:

- at least one actinic radiation source, for example having one or more ultraviolet lamps, configured to emit a radiation directed towards the operative side of the conveyor 2 and affecting the whole width of the conveyor 2,

- at least one thermal source directed towards the operative side of the conveyor 2 and affecting the whole width of the conveyor 2.

As shown in figure 2 and according to a preferred embodiment, the solidification station 20 is arranged outside the conveyor 2 and it is configured to direct the actinic and/or heat source towards the upper segment 2a of the conveyor 2, in particular for directing the radiation towards the composite material inside the forming cavity 3. A solution having the simultaneous supply of actinic and heat source can be implemented with the aim of reducing the time required for the full or partial solidification of the synthetic resin 6.

A control unit 50 is configured to adjust at least one actinic radiation source emission parameter, particularly at least the actinic radiation intensity. Furthermore, the control unit 50 is configured to adjust, alternatively to actinic radiation or combined therewith, at least one thermal source emission parameter, particularly at least the thermal source intensity. The adjustment of the actinic source or the thermal source may be as a function of a speed parameter of the conveyor 2, optionally as a function of the speed set to, or the detected speed of the conveyor 2. Furthermore, the adjustment of the actinic source and the thermal source can be as a function of the chemical composition of the synthetic resin 6 used, as well as the type of reinforcement fibres 5 present.

In a further embodiment, the conveyor 2 and/or the plurality of projecting elements 10 comprise a heater 19 providing a heat source to define a predefined temperature at least at the upper segment 2a of the conveyor 2 or of the plurality of the projecting elements 10. In particular, the heater 19, comprises one or more electrical resistors positioned along the conveyor 2, particularly at the plurality of projecting elements 10, so that the flow of a predetermined electric current caused by a predetermined electric potential difference defines a heat source. Even more in particular, the electrical resistors can be located inside the projecting elements 10 or arranged at the base body 9 of the conveyor 2.

Thus, the heater 19 is configured to define a temperature profile at least along the upper segment 2a of the conveyor 2, particularly at the plurality of the projecting elements 10. Thus, the heater 19 described herein enables obtaining a desired temperature profile along the advancement direction A of the conveyor 2, so as to be able to monitor the temperature in different positions of the conveyor, so as to set a predetermined solidification temperature.

The apparatus 100 comprises at least one temperature sensor configured to emit a temperature monitoring signal at one or more points of the conveyor 2 and/or of the projecting elements 10 and connected to the control unit 50 configured to receive - in input - a value of a predetermined temperature or a temperature profile along the conveyor 2, receive - in input from the temperature sensor - the temperature monitoring signal, compare the predefined temperature value or profile along the conveyor 2 with the temperature monitoring signal, adjust at least one heater control parameter so as to minimise the difference between the predetermined temperature or the temperature profile along the conveyor 2 with the corresponding temperature monitoring signal.

The control unit 50 is also configured to adjust at least one actinic radiation source emission parameter, in particular at least the actinic radiation intensity, as a function of the of the speed set to or the detected speed of the conveyor 2 or as a function of the synthetic resin 6 used, as well as the type of reinforcement fibres 5 present.

The apparatus 100 further comprises at least one station 8 for separating the continuous artifact from the conveyor 2, wherein the separation station 8 operates downstream of the conveyor 2 and it comprises at least one guide member, optionally comprising one or more rollers and/or one or more conveyor belts, configured for engaging a portion of the continuous artifact 7 exiting the solidification station 20 and for conferring it a trajectory suitable to cause a removal of the continuous artifact 7 from the forming cavity and a separation of the continuous artifact 7 from the conveyor 2. The separation station 8 optionally comprises a further conveyor belt arranged downstream of the conveyor 2 and configured to support the continuous artifact 7 downstream of the solidification station 20, so as to determine the removal of the continuous artifact 7 from the forming cavity 3.

In a further embodiment, the juxtaposed joining segment 2d of the conveyor belt 2 arranged downstream of the solidification station 8 defines a curvature of the conveyor belt 2, so that the forming cavity 3 defined by the projecting elements 10 in such juxtaposed joining segment 2d of the conveyor 2 modifies facilitating the removal of the continuous artifact. In particular, the first part 14a, 15a and the second part 14b, 15b of the cross-section 14, 15 of the conveyor 2 vary the shape thereof at the juxtaposed joining segment 2d of the conveyor 2. The solidification station 20 and/or the heater 9, may optionally define - downstream of the conveyor belt 2 - a predetermined temperature facilitating the removal of the continuous artifact 7 from the forming cavity 3. In particular the heater 19 may define - downstream of the conveyor 2 and at the output segment - a lower temperature at a previous segment of the conveyor 2 with respect to the advancement direction A, so as to facilitate shrinking of the continuous artifact 7 made of composite material and thus the facilitated removal thereof from the forming cavity 3.

The depositing device 4 comprises at least one element, for example a spool 21, for supplying a fibre or one or more sets of fibres of reinforcement material 5. In particular, the depositing device comprises a fibre guide member 23 arranged between the spool 21 and the conveyor 2 and configured to guide a deposition of the fibres previously impregnated in the first and/or in the second channels 11, 12. The fibre guide member 23 is optionally arranged between the impregnation station 22 (not shown in the attached figures) and the conveyor 2. Thus, the fibre guide member 23 is configured to define the position of the bundle of reinforcement fibres 5 in the forming cavity 3. In an optional embodiment, the guide member 23 e mobile with respect to the conveyor 2, in particular positioned at the joining segment 2c of the conveyor 2 and mobile in the transversal direction with respect to the advancement direction A of the conveyor 2. During the transversal movement thereof, the guide member 23 is configured to grasp a bundle of reinforcement fibres 5 and guide them in one or more of the first defined channels 11 of the projecting elements 10 according to a predetermined depositing scheme of the reinforcement fibre 5. The depositing device 4 alternatively or jointly comprises a further guide member 23' mobile with respect to the conveyor 2, in particular positioned laterally to the conveyor 2 and mobile along the advancement direction A of the conveyor 2. During the longitudinal movement thereof, the further guide member 23 is configured to grasp a bundle of reinforcement fibres 5 and guide them in one or more of the second defined channels 12 of the projecting elements 10 according to a predetermined depositing scheme of the reinforcement fibre 5. Given that the projecting elements 10 are displaced by means of the conveyor 2, the further guide member 23' is configured for synchronising the positioning of the fibre 5 in the second channels 12 with the advancement speed of the conveyor 2. The apparatus 100 optionally comprises a cutting station configured for cutting, laterally to the conveyor 2, the bundle of fibres arranged along the second channels 12 so as to enable the advancement of the conveyor 2.

The control unit 50 is thus configured for controlling the displacement of the guide member 23 of the further guide member 23' at least as a function of the displacement speed of the conveyor 2.

The control unit 50 is configured to adjust the mass amount of fibre 5 deposited in the forming cavity 3 per time unit and/or an amount of synthetic resin 6 deposited over the time unit inside the forming cavity 3 as a function of a speed parameter of the conveyor 2 and/or as a function of the speed set to, or the detected speed of the conveyor 2. The mass amount of fibre 5 deposited in the forming cavity 3 per time unit and/or the amount of synthetic resin 6 is also as a function of the type of the reinforcement fibre, in particular the mass thereof per surface unit, as well as the method with which the fibre guide member 23 arranges the reinforcement fibres 5 in the forming cavity 3, in particular as a function of the weaving of the fibres 5 along the first and second channels 11, 12.

The apparatus 100 further comprises at least one adjustment squeegee blade 25 active at the operative side of the conveyor 2 and downstream of the depositing device 4. The squeegee blade 25 extends transversely above the operative side of the conveyor 2 to remove any surplus resin 6 and define a continuous artifact 7 with controlled thickness. The squeegee blade 25 may define a contact with the upper portion of the conveyor 2 so as to effectively remove the surplus resin 6 deriving from the dispensing nozzle 24. Furthermore, the squeegee blade 25 comprises a system configured for varying the contact pressure between the lower portion of the squeegee blade 25 with the upper portion of the conveyor 2 so as to control the operation for removing the surplus resin 6. The squeegee blade 25 optionally defines a contact pressure between the lower portion thereof and the upper portion of the conveyor 2 so as to contribute to compacting the composite material of fibres 5 and synthetic resin 6 that is liquid or in solidification step.

Thus, the control unit 50 is configured to adjust at least one distance between the lower active edge of said squeegee blade 25 and the conveyor 2, optionally for adjusting the contact pressure between the lower portion of the squeegee blade 25 and the upper portion of the conveyor 2, as a function of the speed set to or the detected speed of the conveyor 2, further or alternatively as a function of the type of synthetic resin 6 dispensed by the nozzles 24.

As shown in figure 2, the apparatus 100 comprises a cutting station 26 configured for cutting the continuous artifact 7 transversally to the advancement direction A thereof to define, starting from said continuous artifact (7), a plurality of reticular bodies (1) separated from each other. In particular, the cutting station 26 comprises a reciprocating motion rotating blade, a water cutting system of the water-jet type, a laser cutting system, a shearing machine. The control unit 50 is thus configured to receive - in input - a signal representing a desired length of the reticular bodies 1, controlling the sequentiality of the operations of the cutting station 26 as a function of the speed set to or the detected speed of the conveyor 2.

The apparatus 100 comprises at least one operative condition in which it is configured to obtain the continuous artifacts 7 and/or the reticular-structured single bodies 1, and an inoperative condition in which said apparatus is inactive. The projecting elements 10 have an engagement system 27 configured to constrain the projecting elements 10 to the base body 9 of the conveyor 2, wherein the engagement system is configured to define a stable constraint between the projecting elements 10 and the base body 9 of the conveyor 2 during the operative condition as well as to define a removable constraint between the projecting elements 10 and the base body 9 of the conveyor 2, during the inoperative condition so as to enable the replacement and/or modification of the position of the projecting elements 10.

The apparatus 100 further comprises, in a further embodiment, a compaction roller arranged at the operative side of the conveyor 2, in particular positioned downstream of the depositing station 4 and of the nozzles 24 for dispensing the synthetic resin. The compaction roller acts pushing on the operative side of the conveyor 2 and it is configured to compact the composite material contained in the forming cavity 3, in particular when the synthetic resin is in the liquid or semi-liquid state, so as to facilitate the elimination of the surplus synthetic resin 6 present between the reinforcement fibres 5. The compaction roller acts pushing on the whole width of the conveyor 2. The compaction roller optionally acts pushing at the solidification station 20 and up to the separation station 8. In an alternative embodiment, the compaction roller has a series of counter-shaped projections with respect to the first and second series of channels 11, 12 of the conveyor 2, configured to be at least partly inserted into the latter so as to define a contact with the composite material present therein and, thus, facilitate the compaction of the material. The compaction roller also has at least one layer of non-stick material 17, in particular coating the entire surface of the compaction roller.

IMPLEMENTATION PLANT

Described hereinafter is a plant 200 suitable to obtain reticular- structured bodies, in particular grids, comprising at least one first apparatus 100 of the previously described type and configured for the formation of a first grid 30, and at least one assembling station 28 configured to receive a second grid 31 and couple it to the first grid 30 so as to obtain a single body 29 comprising the first and second grid 30, 31 coupled to each other (see figure 4) . The plant 200 optionally comprises a second apparatus of the previously described type and configured for obtaining the second grid 31.

The assembling station 28 of the plant 200 comprises at least one glue distributor configured to apply a gluing material 32 to the first and/or to the second grid 30, 31, and a guide system for guiding and arranging the first and second grid 30, 31 adjacent to each other. In particular, the assembling station 28 receives the first and the second grid 30, 31 and provides a predetermined type and amount of gluing material 32 at the contact surface between the first and the second grid 30, 31, in particular along at least one maximum extension surface of the grids. According to a preferred embodiment, the gluing material is a synthetic resin, in particular an epoxy resin. The cross-linking or polymerisation of the gluing material 32 occurs by providing a heat source. The cross-linking of the gluing material 32 optionally occurs by means of the presence of a cross-linking substance which guarantees full or partial cross- linking of the gluing material 32 without requiring a heat source. The guide system of the plant 200 can be a mould inside which the first grid 30 and the second grid 31 are inserted so as to guarantee the correct adjacent arrangement and the subsequent gluing thereof. The guide system alternatively provides for using one or more sensors configured to monitor at least one relative position between the first and second grid 30, 31.

In an embodiment shown in figure 5, the plant 200 comprises a first apparatus 100 configured to obtain a first grid 30 wherein the first channels 11 are spaced from each other by a pitch PI and the second channels 12 are spaced from each other by a pitch P2, and a second apparatus configured to obtain a second grid 31 in which the first channels 11 are spaced from each other by a pitch P10 and the second channels 12 are spaced from each other by a pitch P20. The pitch PI of the first channels 11 of the forming cavity 3 of the first apparatus 100 is greater than, preferably multiple of the pitch P10 of the first channels 11 of the forming cavity 3 of the second apparatus, while the pitch P2 of the second channels 12 of the forming cavity 3 of the first apparatus is greater than, preferably multiple of the pitch P20 of the second channels 12 of the forming cavity 3 of the second apparatus 100.

According to the latter embodiment shown in figure 5, there can thus be provided for the use of a first grid 30 having a closely-knitted reticulation, in particular a grid obtained by means of a conveyor 2 having a small distance between the plurality of the first channels and a small distance between the plurality of the second channels, and a grid having a wider reticulation with respect to the previous one, in particular a grid obtained by means of a conveyor 2 having a high distance between the plurality of the first channels and a high distance between the plurality of the second channels. This enables obtaining a first and a second grid so that the second grid is configured to support the mechanical load during use and wherein the first grid, arranged adjacent and glued to the grid like in figure 5, is configured to enable treading thereon.

IMPLEMENTATION METHOD

Following what has been described in a substantially structural manner, described below is a process for manufacturing reticular or grilled bodies made of reinforced synthetic resin. The process described hereinafter uses - by way of example - apparatus according to what has been described above and/or according to the subject of claim in the attached claims.

The manufacturing process comprises the following steps.

Firstly, a step is provided for displacing at least one reticular- shaped forming cavity 3 along a pre-set operative path, in particular along an advancement direction A. The step of displacing the forming cavity 3 provides for the use of a conveyor 2 arranged as a closed loop conferring a motion to the forming cavity 3 along a pre-set operative path. The implementation method further comprises a depositing step comprising positioning the dry reinforcement fibre 5 inside said forming cavity 3, positioning the synthetic resin 6 at liquid state at contact with the reinforcement fibre 5, in particular in the forming cavity 3. The implementation method alternatively comprises a step of positioning the reinforcement fibre 5, pre-impregnated with the synthetic resin 6, inside the forming cavity 3. Furthermore, the implementation method provides for forming, inside the forming cavity 3, at least one portion of a semi-finished continuous artifact 7 made of composite material. The depositing step comprises supplying a fibre or a set of fibres of a reinforcement material 5, for example by means of a spool 21, to the conveyor 2. Furthermore, the implementation method provides for guiding, upstream of the conveyor 2 and by means of a guide member, the fibre or the set of reinforcement fibres in the first and second channels 11, 12 defining the forming cavity 3 according to a predefined weaving scheme.

Furthermore, the depositing step comprises impregnating the reinforcement fibres 5 with a predetermined amount of synthetic resin 6 at liquid state, and injecting a predetermined amount of synthetic resin 6 at liquid state into one or more of the forming cavities 3 by means of an injection nozzle 24.

The depositing step further comprises monitoring a mass amount of reinforcement fibre 5 deposited in the forming cavity 3, and monitoring an amount of the synthetic resin 6 deposited over the time unit in the forming cavity 3. Furthermore, it comprises adjusting, by means of a control unit 50, the supplied mass amount of fibre 5 and/or the amount of synthetic resin 6 as a function of a parameter representing the speed set to, or the detected speed of the conveyor 2.

Furthermore, the manufacturing method comprises a solidification step to enable an at least partial solidification of the synthetic resin 6 present in the forming cavity 6, particularly at the upper segment 2a of the conveyor 2, to define a reticular-structured continuous artifact 7. The solidification step comprises a step of emitting an actinic radiation, optionally by means of ultraviolet lamps, towards the upper segment of the conveyor 2 affecting the whole width of the latter. The solidification step alternatively or jointly comprises providing a thermal source directed towards or at the upper segment 2a of the conveyor 2, particularly at the forming cavity 3, affecting the whole width of the latter.

The manufacturing method comprises a step of removing any surplus resin 6 by using a squeegee blade 25, subsequent to the step of impregnating and/or injecting the synthetic resin 6 onto the reinforcement fibres 5. The manufacturing method further comprises monitoring a distance and/or a contact pressure between an active lower edge of the squeegee blade 25 and the conveyor 2, particularly between an active lower edge of the squeegee blade 25 and at least one projecting element. Furthermore, a step is provided for adjusting, by means of a control unit 50, the distance or contact pressure as a function of the speed set to or the detected speed of the conveyor 2, alternatively or jointly as a function of the parameter representing the predetermined amount of synthetic resin 6 supplied during the impregnation and/or injection step.

The implementation method further comprises a step of removing the portion of the continuous artifact from the forming cavity 3. The step of removing the continuous artifact 7 occurs after the solidification step. The removal of the continuous artifact 7 from the forming cavities 3 downstream of the conveyor 2 occurs by means of a guide member 23, optionally by means of one or more rollers or several conveyor belts.

The manufacturing method comprises step of cutting the continuous artifact 7 transversally to the advancement direction A thereof, after the step of removing the portion of the semi-finished continuous artifact 7 from the forming cavity 3. It should be observed that the steps of the method for manufacturing reticular-structured bodies described above, can be implemented by using the apparatus 100 described in the previous section.

In an embodiment, the method comprises the step of providing a first grid 30 by using an apparatus 100 similar to the one described previously, obtaining a second grid 31 and thus coupling the first and second grid 30, 31 to define a single body 29.

The step of coupling the first and the second grid 30, 31 provides for applying at least one gluing material 32 to the first and/or second grid 30, 31, and arranging the first and second grid 30, 31 adjacent to each other, particularly along the main extension plane, so as to define a mutual gluing.

The step of manufacturing the second grid 31 optionally occurs by using the apparatus 100 described previously.

Furthermore, the manufacturing method comprises a step of cutting the reticular-structured single body 29 transversally to the/an advancement direction (A) thereof to define a plurality of reticular- structured single bodies 29.

PRODUCT

The reticular-structured continuous artifact 7 (see figure 3) is obtained by means of an apparatus 100 or a plant 200 of the type according to the preceding description. The reticular-structured continuous artifact 7 is obtained by implementing a method as described previously.

The continuous artifact 7 comprises a plurality of longitudinal elements 58, extending parallel to the advancement direction A of the conveyor 2 of the apparatus 100, and a plurality of transversal elements 59 intersecting with the longitudinal elements. In particular, the longitudinal elements 58 and the transversal elements 59 are joined in a single piece. The continuous artifact 7 optionally has an infinite length.

In a preferred embodiment, the continuous artifact 7 is subjected to a cutting operation at the cutting station 26, to define at least one reticular-structured single body 1, in particular a grid, having a plurality of longitudinal elements 60 and a plurality of transversal elements 61 joined to the longitudinal elements 60 in a single piece.

The reticular-structured single body 1 is obtained by means of an apparatus 100 or a plant 200 according to the preceding description. Furthermore, the discrete body is obtained by means of a method as described previously, following an operation for the transversal cutting of the continuous artifact.

The continuous artifact 7 and/or the reticular-structured single body 1 have a section of the longitudinal elements and a section of the transversal elements substantially counter-shaped with respect to the channels of the first and of the second series 11, 12 of the apparatus 100, in particular they have a T or L-shaped section.

The particular elongated shape of the first part 14a, 15a of the first and of the second channels 11, 12 defines a continuous artifact 7 and/or a reticular-structured single body 1 having a greater resistance to bending, in particular the particular T or L shape defines a high bending moment of inertia of the grid. The particular widened conformation of the second part 14b, 15b of the first and of the second channels 11, 12 defines a continuous artifact 7 and/or a reticular-structured single body 1 having a large treadable surface .

According to one of the embodiments of the apparatus 100 and the method 200, the continuous artifact 7 and/or the reticular- structured single body 1 have an amount of reinforcement fibres 5 parallel to the advancement direction of the conveyor 2 of the apparatus 100 greater than the number of reinforcement fibres 5 positioned in transversal direction. In particular, the amount of longitudinal reinforcement fibres 5 represent at least 60% of the total of the fibres contained in the continuous artifact 7 and/or of the reticular-structured single body 1.

PROCESSING UNIT

The control unit 50 may comprise a single central unit which controls the functionalities described above or a plurality of units each part of a respective subsystem of the apparatus 100. The unit 50 may be of the digital or analogue type or it may combine digital part and an analogue type. The control unit 50 comprises - or it is connected with - one or more memories designated to store a programme which enables the unit to perform the previously described functions upon executing the unit 50.

MATERIALS

The fibrous reinforcement material, for example made of fabric or non-woven fabric, or made of filaments can be obtained from synthetic reinforcement fibres such as carbon fibre, glass fibre, aramid fibre, Kevlar, boron fibre or using natural fibres such as natural fibres of animal origin or natural fibres of plant origin.

The synthetic resin is a thermosetting resin comprising for example polyester resins, vinylester resins, epoxy resins, phenolic resins and other types of resins. In some applications, there can be provided for the use of thermoplastic synthetic resins.

The active agent indicated in the description and in the claims can be not only a cross-linking catalyst, or a cross-linking accelerator, but also:

- a cross-linking agent,

- an agent including both a catalyst and cross-linking accelerator,

- an agent including a cross-linking agent, and an accelerator, - an agent including a cross-linking agent, and a catalyst,

- an agent including a cross-linking agent, an accelerator and a catalyst .

ADVANTAGES

The apparatus and process described above enables obtaining the possibility of forming continuous grilled bodies with controlled thickness and without wasting any resin.

The productivity achieved through the described process is obviously greater than that typical of conventional moulding systems.

Furthermore, the process and apparatus described above enable obtaining reticular or grilled bodies of various sizes and mechanical characteristics, without having to change the key components of the production system.