Field of The Invention

[0001 ] The present invention generally finds application in the field of stone and ceramic processing and particularly relates to a resin line for manufacturing reinforced stone or ceramic slabs.

Background art

[0002] In the field of stone or ceramic slab or block processing, sheet elements of predetermined sizes have been long known to be laid on a surface of the slabs or blocks.

[0003] These sheet elements are used to reinforce the structure of the slabs or blocks and to provide a uniform surface for firm fixation of the slabs on horizontal and vertical walls.

[0004] Generally, the sheet elements comprise fiberglass or carbon mats, which are attached to the surfaces of the slabs or blocks using two-component resins.

[0005] Such resins are usually epoxy resins and are first sprayed on the surfaces to be reinforced and then spread thereon to form a uniform layer. The mat is applied on the resin before or after spreading and is partially buried therein.

[0006] WO201 6/1 781 12 discloses a method for reinforcing stone blocks which includes a step of carrying the blocks along a processing line on a carriage, a step of layering the blocks with a resin by spraying and a step of applying a fiberglass mat on the resin.

[0007] The resin is sprayed using a nozzle that moves relative to the block and the mat is stretched before application, for complete, uniform adhesion thereof to the block surface.

[0008] In order to prevent resin leakage along the surfaces of the block, the step of stretching and applying the mat is carried out immediately after the resin spraying step.

[0009] ES2382064 discloses a machine for reinforcing stone slabs by applying a fiberglass mat on one surface of the slabs.

[0010] The machine comprises a slab feeding line, a bridge structure and a carriage that is slidingly mounted to the bridge structure and is adapted to support respective tools for spraying the resin and applying the mat.

[0011] A first drawback of these arrangements is that during spraying the resins may scatter and leak onto other parts of the machines, e.g. on the slab or block feeding means, thereby affecting operation thereof.

[0012] A further drawback of these arrangements is that these machines require frequent maintenance and cleaning, to remove the deposited resins.

[0013] Another drawback is that, after spraying, the resins tend to leak along the slab surfaces and form aesthetically unpleasant ribs.

[0014] Immediate application of the mat only partially attenuates this drawback and is only possible with particular types of resins having predetermined cure times.

[0015] A further drawback is that such arrangements do not include adequate means for spraying and spreading polyurethane resins, which are much more flexible than epoxy resins and more suitable for mat application.

[0016] Yet another drawback is that these machines are poorly efficient and their processes include many dead times, due to the time required for resin curing and hardening.

[0017] A further drawback of these arrangements is that when resins are sprayed on slabs with irregular edges, considerable resin waste occurs, as resin deposits on the side edges of the machines.

[0018] Another drawback is that these machines are not able to spray different amounts of resin on different areas of the slab, e.g. at unevennesses or defects of the slab.

Technical Problem

[0019] In the light of the prior art, the technical problem addressed by the present invention is to provide a resin line for manufacturing reinforced stone or ceramic slabs which can avoid resin scattering and leakage and requires less maintenance and cleaning by operators. Disclosure of the invention

[0020] The object of the present invention is to obviate the above drawback, by providing a resin line for manufacturing reinforced stone or ceramic slabs, that is highly efficient and relatively cost-effective.

[0021] A particular object of the present invention is to provide a resin line as described hereinbefore that can avoid resin scattering during spraying.

[0022] A further object of the present invention is to provide a resin line as described hereinbefore that can avoid leakage of resins from the slab surfaces that have been sprayed therewith.

[0023] Another object of the present invention is to provide a resin line as described hereinbefore, that requires less cleaning and maintenance by operators.

[0024] A further object of the present invention is to provide a resin line as described hereinbefore that can avoid scattering and leakage of resins without hindering the spraying and spreading steps.

[0025] Yet another object of the present invention is to provide a resin line as described hereinbefore, that affords use of different types of resins.

[0026] A further object of the present invention is to provide a resin line as described hereinbefore, that is highly efficient and has reduced dead times.

[0027] Another object of the present invention is to provide a resin line as described hereinbefore that affords uniform spraying of resin even at irregular edges of a slab, or at any unevennesses or defects thereof, thereby reducing resin waste.

[0028] These and other objects, as more clearly explained hereinbelow, are fulfilled by a resin line for manufacturing reinforced stone or ceramic slab, comprising a loading station for loading one slab at a time, a spraying station for spraying a substantially uniform layer of a resin on the top surface of each slab through at least one nozzle, a deposition station for depositinga strengthening fabric mat on the top surface of the slab and bury it in the resin layer, a doctoring station for removing excess resin from the fabric mat using at least one doctor blade, a drying and curing station for drying and curing the resin at a predetermined temperature, an unloading station for unloading the resin-reinforced and cured slabs and support and feeding means for supporting and feeding the slabs between stations in a longitudinal direction and on a support plane for the slabs.

[0029] The spraying and doctoring stations comprise guard means configured to be selectively positioned proximate to and under the side edges and end edges of the slabs during spraying and doctoring to prevent the resin from depositing on the feeding means and later soiling the bottom surfaces of the slabs.

[0030] The guard means have a variable geometry, to selectively fit the size of each slab.

[0031 ] Advantageous embodiments of the invention are obtained in accordance with the dependent claims.

Brief Description of The Drawings

[0032] Further features and advantages of the invention will be more apparent upon reading of the detailed description of a preferred, non-exclusive embodiment of a resin line for manufacturing reinforced stone or ceramic slabs according to the invention, which is described as a non-limiting example with the help of the annexed drawings, in which:

FIG. 1 is a perspective view of the resin device of the invention;

FIG. 2 is a broken-away lateral view of the resin line of Fig. 1 ;

FIG. 3 is a lateral view of the deposition station of the resin line of Fig. 1 ; FIG. 4 is a perspective view of the loading station of the resin line of Fig.

1 ;

FIG. 5 is a perspective view of a first detail of the loading station of Fig. 4;

FIGS. 6 to 8 are perspective, broken-away lateral and broken-away front views of a detail of the spray and doctoring stations in a first operating configuration;

FIGS. 9 and 10 are perspective and broken-away lateral views of the detail of Figs. 6 to 8 in a second operating configuration;

FIG. 1 1 is an enlarged view of the detail of Fig. 1 0; FIGS. 1 2 and 1 3 are a broken-away front view and a respective enlarged view of the detail of Fig. 9;

FIGS. 14 and 1 5 are perspective views of the spray and doctoring stations with additional details;

FIGS. 1 6A to 17B are perspective and front views of a detail of the spraying station of the line of Fig. 1 .

Detailed description of a preferred exemplary embodiment

[0033] Particularly referring to the figures, there is shown a resin line, generally designated by numeral 1 , for manufacturing reinforced stone or ceramic slabs S.

[0034] The material of the slabs S to be reinforced may be selected from the group comprising stone, cementitious agglomerates, marble and ceramics.

[0035] In a preferred configuration of the invention, the resin line 1 comprises a loading station 2 for loading one slab S at a time, which has a rigid frame 3 defining a substantially horizontal loading plane ττ, as shown in FIG. 4.

[0036] Slabs S are placed on the loading plane π by well-known devices, with an upwardly facing top surface S' and a bottom surface S" in contact with the loading plane ττ.

[0037] A spraying station 4, as shown in FIGS. 6 to 14, is situated downstream from the loading station 2, for spraying a substantially uniform layer of a resin R on the top surface S' of each slab S through at least one nozzle 5.

[0038] Advantageously, the resin R is a two-component resin, i.e. is used in combination with a catalyst, and is a polyurethane resin. In operation, this type of resin R must be maintained a temperature ranging from 38 °C and 42 °C and is much more flexible than epoxy resins, that are typically used in this field.

[0039] The resin line 1 comprises a deposition station 6 for depositing a strengthening fabric mat F on the top surfaces S' of the slabs S, to bury it in the layer of resin R, and a doctoring station 7 for removing excess resin R from the mat F using at least one doctor blade 7'.

[0040] As shown in FIG. 3, the deposition station 6 for depositing the mat F may comprise a dispenser having a plurality of rollers 8 and configured to uniformly stretch a section of the mat F from a roll 9 and cut it to size, to fit the size of the slab S.

[0041 ] Furthermore, the dispenser comprises a cutter 6' for cutting the mat F and a pair of specially shaped metal members 6", located under and facing the rollers 8 for guiding the mat F toward the cutter 6'.

[0042] Advantageously, each roller 8 will be associated with an air blower device 1 0 which is adapted to generate an air-knife directed toward its respective mat F to stretch it and convey it onto the rollers 8, namely into the nip 8 between the rollers and their respective specially-shaped elements 6", as the roll 9 is changed.

[0043] The blower device 1 0 may comprise a transverse tubular element having a predetermined diameter. The tubular element 1 0 may be connected at one end to a pressurized air source and may have a series of holes on its surface, for distributing air on the rollers 8.

[0044] Alternatively, the air-knife may be generated by a continuous, transverse aperture formed on the surface of each blower device 1 0 and parallel to its respective roller 8.

[0045] The slabs S are moved from the loading station 2 to the doctoring station 7 using support and feeding means 1 1 connected to a control unit, in a longitudinal direction L and on a support plane ττ' for the slabs S, which also has a substantially horizontal orientation.

[0046] As shown in FIGS. 6 to 1 3, both the spraying station 4 and the doctoring station 7 comprise respective similar rigid frames 1 2, each comprising a pair of longitudinal side walls 1 3.

[0047] The frames 1 2 are equipped with lifting means 14 for each slab S, which are designed to selectively act upon the bottom surface S" of the slab and to lift it from the support plane ττ'.

[0048] As shown in the FIGS. 6 to 1 3, the lifting means 14 comprise a plurality of support bars 1 5 having the shape of a parallelepiped, which are arranged in longitudinal rows and are connected to the processor-based control unit, not shown.

[0049] The bars 1 5 are configured to be vertically moved from a rest position, in which their upper edge 1 6 is located below the support plane ττ', to an operating position, in which their upper edge 1 6 interacts with the bottom surface S" of the slab S to lift it from the support plane ττ', and vice versa.

[0050] In the embodiment as shown in the figures, the support and feeding means 1 1 comprise a plurality of trays 1 7, as shown in FIG. 5, which are substantially flat and define the support plane ττ'.

[0051 ] Furthermore, the feeding means 1 1 comprise at least one pair of closed-loop chains or belts 1 8 subtended by powered end gear rings or wheels 1 9, located on opposite sides of the frames 1 2, at the longitudinal walls 1 3, and connected to the control unit for laterally driving the trays 1 7 in the longitudinal direction L.

[0052] Advantageously, the trays 1 7 may have a lattice structure with a rigid peripheral rim 20 designed for interaction with the belts or chains 1 8, and meshes 21 of predetermined size.

[0053] When the trays 1 7 are located in the spraying station 4 and the doctoring station 7, the meshes 21 of the trays 1 7 are aligned with the bars 15 of the lifting means 14.

[0054] Thus, the bars 15 can be vertically moved to the operating position through the meshes 21 , to thereby lift each slab S relative to its corresponding tray 1 7.

[0055] In an alternative embodiment of the invention, not shown, the support and feeding means 1 1 may comprise a powered roller bed, which is also connected to the control unit and has no support trays.

[0056] As shown in FIGS. 14 and 1 5, the spraying station 4 and the doctoring station 7 comprise first 22 and second 23 motorized arms, which are configured to support the nozzle 5 and the doctor blade T respectively and are connected to the control unit.

[0057] The arms 22, 23 may be mounted to respective movable carriages 24, sliding along respective longitudinal guides 25 installed above the horizontal support plane ττ' and may be adapted to rotate about respective vertical axes V.

[0058] Advantageously, the nozzle 5 may have jet deflecting means 26 associated therewith, for limiting and adjusting the size of the spray cone R', thereby limiting deposits of resin R on the feeding means 1 1 .

[0059] In a first embodiment, these directing means 26 may comprise at least one pair of lateral screens 27, fixedly secured to the first arm 22.

[0060] These lateral screens 27 are secured proximate to and on opposite sides of the nozzle 5, and are adapted to transversely delimit the width of the spray cone R', as shown in FIG. 14.

[0061 ] In a second embodiment, the directing means 26 may be of motorized type and comprise a cylindrical screen 28 having a predetermined inside diameter di , which is mounted at the periphery of the nozzle 5 and is adapted to move coaxial therewith to delimit the spray cone R'.

[0062] The cylindrical screen 28 is coupled to a motorized device 29 of the type having a linear motor or a piston, for causing it to vertically translate from a rest position, raised relative to the nozzle 5, to an operating position, lowered relative to the nozzle 5.

[0063] Thus, the cylindrical screen 28 may change the width of the spray cone R' between a minimum value, corresponding to the inside diameter di of the screen 28, as shown in FIG. 1 7B, and a maximum value d2 of the spraying action on the slab S, as shown in FIG. 1 7A.

[0064] The nozzle 5 may be in fluid communication with and in parallel to the resin and catalyst supply line 30.

[0065] This line 30 may be in turn connected to respective reservoirs 31 via corresponding hydraulic circuits, not shown, and heating means may be associated with the line 30 and the circuits.

[0066] The heating means, not shown, allow the resin R and the catalyst to be maintained at the aforementioned predetermined temperature, to allow continuous flow and uniform distribution thereof on the surface S' of the slabs S. [0067] The reservoirs 31 and the pumps connected to the nozzle 5 may be placed on the upper walkway surface 32 of the spraying station 4, as shown in FIGS. 1 and 2.

[0068] The resin line 1 comprises, downstream from the doctoring line 7, a drying and curing station 33 for drying and curing the resin R at a predetermined temperature and an unloading station 34 for unloading the reinforced slabs S.

[0069] Similar to what has been described above, the slabs S may be carried from the doctoring station 7 to the drying station 33 and the unloading section 34 by means of the belt-driven feeding means 1 1 .

[0070] Advantageously, sensor means may be arranged in the doctoring station 7 and the spraying station 4 and electrically connected to the processor- based control unit.

[0071 ] Namely, the sensor means are configured to detect the presence or absence of the slab S in the doctoring station 7, such that the control unit that receives the detection signal will prevent the nozzle 5 from spraying the resin R on one slab S when one downstream slab Si is still in the doctoring station 7.

[0072] This will prevent the resin R sprayed on a slab S from curing and hardening before reaching the doctoring station 7, which would prevent spreading thereof.

[0073] The resin line 1 may comprise an electronic pointer, not shown, for identifying and marking unevennesses and/or imperfections on the top surface S' of each slab S.

[0074] The electronic pointer may comprise a telescopic rod, moved by an operator, having a sensor at its end for marking the area of the slab S characterized by imperfections such as, for example, voids or cracks.

[0075] Advantageously, optical detection means, also not shown, may be arranged in the loading station 2 and electronically connected to the control unit to detect the marks made by the pointer such that, in the subsequent spraying station 4, an appropriate amount of resin R may be sprayed on the unevennesses through the nozzle 5.

[0076] In a peculiar aspect of the invention, the spraying station 4 and the doctoring station 7 comprise guard means 35 configured to be selectively positioned proximate to and under the lateral edges E' and the end edges E" of the slabs S.

[0077] The guard means 35 have a variable geometry to selectively fit the size of each slab S and to prevent the sprayed resin R from depositing on the feeding means 1 1 and from later soiling the bottom surface S" of the slabs S.

[0078] The guard means 35 are also connected to the control unit so that their movement may be coordinated with the movement of the feeding means 1 1 and that they will be only actuated when the slab S is located in the respective stations 4, 7.

[0079] Advantageously, the guard means 35 may comprise a pair of longitudinal profiles 36, 36' and a pair of transverse profiles 37, 37' mounted to the respective frames 1 2 of the spraying station 4 and the doctoring station 7.

[0080] The longitudinal profiles 36, 36' and the transverse profiles 37, 37' define a rim 38 having a substantially rectangular plan shape and with longitudinal and transverse dimensions varying according to the size of the slabs S.

[0081 ] As shown in FIGS. 5 to 1 2, actuator means 39 are further mounted to the frames 1 2 and act on at least one of the longitudinal profiles 36' and on at least one of the transverse profiles 37' to bring them closer to their respective opposite profiles 36, 37 and to the edges E', E" of the slab S and to accordingly vary the longitudinal and transverse dimensions of the rim 38.

[0082] The profiles 36', 37' actuated by the actuator means 39 are configured to slide on respective horizontal planes ττ", located above the support plane ττ', to be only placed at the edges E', E" of the slab S when the latter has been lifted by the lifting means 14 from the support plane ττ'.

[0083] The profiles 36, 36', 37, 37' may consist of substantially horizontal thin straps 40, designed to at least partially fit under the edges E', E" of each slab S. [0084] The straps 40 may also be layered with Teflon or other similar inert materials or formed of one piece with this material to prevent scattering and accumulation of the sprayed resins R. The Teflon layer 41 may be periodically removed and replaced with a new intact Teflon layer.

[0085] The horizontal straps 40 may be connected to vertical straps 43 via respective angular elements 42, to form an L-shaped profile.

[0086] In operation, in the preferred embodiment of the figures, during the spraying and doctoring steps the slabs S are initially placed in the respective stations 4, 7 by the feeding means 1 1 .

[0087] Then, the lifting means 14 are actuated and lift the slabs S from the tray 1 7, or in any case from the support plane ττ', and the guard means 35 are placed at the edges E', E" of the slabs S.

[0088] The resin R is sprayed or spread on the top surface S' of the slabs S and the latter, during the aforementioned steps, are stably supported by the lifting means 14.

[0089] At the end of the spraying or doctoring steps, the guard means 35 are retracted from the edges E', E" of the slabs S by their respective actuators 39 and the lifting means 14 are moved back to their rest position, for the slab S to be placed back on the feeding means 1 1 and be carried to the next station.

[0090] It will be appreciated from the foregoing that the resin line fulfills the intended objects and particularly can prevent resin scattering and accumulation during the spraying and doctoring steps.

[0091 ] While the resin line has been described with particular reference to the accompanying figures, the numerals referred to in the disclosure and claims are only used for the sake of a better intelligibility of the invention and shall not be intended to limit the claimed scope in any manner.

Industrial Applicability

[0092] The present invention may find application in industry, because it can be produced on an industrial scale by stone or ceramic product processing factories.