METHOD AND APPARATUS FOR FORMING MOSAIC PANELS WITH JOINING PVC POINTS

Abstract

 The present invention relates to the field of mosaic panels for coverings and floors, and more specifically, to the one of systems for forming the aforesaid panels. More specifically, the invention relates to a new system for connecting the tiles to one another to form the panel that represents a basic panel product in the practice of placing mosaics. For this purpose, an apparatus and a method are provided for joining adjacent tiles (T) by PVC-like glue points, wherein a glue distribution and scraping means (3) is used to distribute and scrape the glue over a stencil member (2) such that the glue drips though holes (12) in the stencil member (2) while the tiles (T) are being held in cells (11) of a grid (1) made of an elastic, soft and nonstick material.

Description

[0001] The present invention relates to the field of mosaic panels for coverings and floors, and more specifically, to that of systems for forming the aforesaid panels. More specifically, the invention relates to a new system for connecting the tiles to one another through PVC points to form the panel that represents an essential semifinished product in the practice of placing mosaics.

[0002] The aforementioned panels, as known, are compositions of tiles (made from glass, marble, ceramic or other materials), joined together in advance in order to facilitate and speed up application, at the same time obtaining a higher quality result, since the tiles are positioned and spaced with the maximum regularity. There are numerous techniques for forming the panels and apparatuses for the automated composition thereof.

[0003] As far as the present invention is concerned, attention will be focused on the systems for fixing together the tiles of a panel, after they have been supplied and arranged, also in terms of orientation, in the desired configuration in organised rows. The prior art includes different types of solution in this regard.

[0004] One of these, which is particularly common, provides for the use of a netting in fiberglass that is applied onto the back face of the tiles (i..e. the rough face that remains invisible when the mosaic is set) and glued to it by means of a cold-applied vinyl glued. The backing netting is flexible and offers consequent advantages in terms of the ability to manipulate the panels, also during application, in which the operator applying them can also recover possible small imprecisions in application, correcting the spacing of the tiles, within certain limits, which is not rigidly constrained by the support. The use of the vinyl glue that remains trapped in the masonry is, however, considered to be unsatisfactory for a few reasons, especially in some types and conditions of application and storage since the water-based glue can be subject to deterioration, especially if exposed to humidity or low temperatures. Moreover, in order for the vinyl glue to ensure adhesion it needs a backing netting with fine mesh that leaves a small surface exposed on the back faces of the tiles, which is not suitable for ensuring an optimal hold when the panel is applied.

[0005] An alternative solution, which is more specifically relevant to the present invention, and a competitive one with regard to the inert nature of the material and the surface exposed on the back faces, provides the use of points of plasticised PVC applied as a bridge between one tile and the next tile, normally one, two or more points for each facing side between the tiles. The glue points are applied at the base of the tiles lying with the back face on a layer of Teflon®-coated material (to prevent adhesions). The plasticised PVC has a substantially liquid consistency at the application temperature (room temperature) and must be hardened by heating.

[0006] The machinery required to implement the method at hand according to such system is intrinsically complex given that it involves dispensing a significant number of points - up to more than 1000 for example, in the case of larger panels proposed by the market - with the best dimensional uniformity possible. The cost and overall bulk of the machinery are ultimately increased due to the presence of large curing ovens required to ensure a cooking of at least 15 minutes at about 180°, required to harden the PVC applied previously at points, as described above.

[0007] The curing with such operating specifications also implies a significant energy consumption and an increased cycle time. To this end, it is useful to note that since the PVC points are at the base of the tiles, and partly below them, the cooking heat must involve the whole mass of the base plate of the tiles, something which increases the complexity and energy demand of the operation. Again, the transport of the tiles from the grids in which they are ordered, to the Teflon®-coated plate may cause the correct spacing, and in general the evenness of the arrangement, to be lost, with the need for additional labour.

[0008] An apparatus according to the preamble of claim 1 is disclosed in patent publication CN103375006, according to which glue points join respective couples of mutually adjacent tiles on the side of the back faces of the same tiles, the apparatus comprising a stencil member adapted to become superimposed to the tiles in orderly pattern, so that respective glue points are set between the tiles, lying with the back faces upwards, through guide holes formed in the stencil member; glue distribution and scraping means distribute and scrape the glue over the stencil member to make the glue drip through the holes. Such system as described in the publication is however ineffective, in terms of a result of acceptable cleanliness and quality.

[0009] The object of the present invention is to provide a system for forming mosaic panels of the type generically ascribable to the one with PVC points, which, contrary to any application methodology actually in use, is at the same time affordable, quick, and nevertheless accurate.

[0010] According to the invention, such objects are attained by the method and apparatus for forming mosaic panels with joining PVC points according to the invention, and by panels thus obtained, which essential characteristics are defined by the respective accompanying independent claims. Further advantageous aspects of the invention are defined by the secondary claims.

[0011] The features and advantages of the method and the apparatus for forming mosaic panels with PVC joining points, and the panels thus obtained according to the present invention, shall be apparent from the description below of an embodiment thereof, made by way of a non-limiting example, with reference to the accompanying drawings in which:

• figure 1 shows an axonometric view of a diagrammatic depiction of a module of apparatus according to the invention, with a group of tiles being processed;
• figure 2 is a similar depiction to the one in figure 1, with an exploded view of the module;
• figure 3 shows a top view of the module of the preceding figures;
• figure 4 is a section view of the module according to the plane identified by arrows IV-IV of figure 3; and
• figure 5 shows an enlarged view of the portion enclosed by the circle V of figure 4.

[0012] With reference to the above figures, according to the invention it is provided to supply a grid 1, preferably made of silicone or in any case elastic, soft material, provided with cells 11 spaced apart, each to house, with the back face facing upwards, a relative tile T of the mosaic panel to be joined, typically with a square profile. Therefore, the cells 11 will be separated by ridges 12, the thickness of which defines the distance (or "joint") between the tiles in the panel formed, and the height of which, that is the development orthogonal to the cell bottom 11 on which the "front face" is supported is, for reasons to be better understood hereafter, comprised between a half and 3/4 of the thickness of the tile, even more preferably about 2/3.

[0013] Over the grid 1 a sheet plate 2 is arranged, substantially having shape and sizes according to those of the grid, and therefore of the panel to be formed, having an arrangement of holes 21 each indicatively circular, of width and positioning such as to replicate the ones desired for the glue points with which to join the tiles T below in the finished panel. The plate 2 thus carries out a function of stencil member for the correct deposit of the glue points, the holes 21 being in correspondence of the ridges 12, involving all the couples of adjacent tiles, that is relative reciprocally facing sides, of preference substantially flush with the average point of the side. The width is particularly such as to expose a small part of the back face, something which is indicatively achieved in a typical circumstance with a width equal to about 1/4 of the length of the side of the tile, being it understood that such value may undergo variations according to the specifications of the panel being processed (among which mainly measurement of the tiles and thickness of the joints). The size of the plate 2 in the direction of the thickness also is a parameter that affects the sizes of the glue point, and that therefore may undergo variations and adaptations based on the circumstances.

[0014] As mentioned, the plate 2 is spaced apart from the grid 1 so as to leave the space for the tiles T, thus ensuring that some clearance remains between the upward face, that as mentioned is the back/rough face, and the plate itself. Such a clearance is in particular functional for the mutual positioning, being it clearly necessary to first arrange the tiles T on the grid, and then to obtain the superimposing between the plate and the grid-tiles set. This result can be achieved in various equivalent manners, according to what in itself is obvious to the expert, for example with a vertically movable plate support system or also with a fixed plate under which the grid is caused to slide by means of a horizontal conveyor system.

[0015] A module of apparatus according to the invention is completed by a head 3 for glue distribution (PVC) arranged above the plate 2 and adapted to dispense the glue so as to cause it to drip through the holes 21. According to a preferred embodiment, the head 3 is movable horizontally above the plate, thus taking on for example, as in the depicted embodiment, the shape of a slider 31 elongated according to a longitudinal axis Y, which extends between the two opposite sides of the plate and moves in reciprocating fashion in a direction X, orthogonal to the axis Y of the slider, to sweep over the whole surface of the plate.

[0016] As shown in particular in figure 5, the slider has a cup-shaped cross-section (that is, a section carried out over a plane orthogonal to the plate and to the axis Y) defining a collection and distribution channel 32 in which there is fed, through an upper manifold 33, the glue (mass indicated with C in such figure 5) intended to fill the holes 21 and to be deposited through them in joining points between the tiles. The distributor channel 32 is between two laminar spatulas 34 that make contact with the plate 2 at the free end edges 34a and thereby are adapted to perform functions of scraping elements, or doctor blades, thus ensuring that the glue is spread and pushed to drip through the holes 22 with the reciprocating movement of the slider in the direction X. To this end, the end edges 34a of the spatulas 34 advantageously may have an appropriate shaping, such as the rounded one of the example illustrated.

[0017] The feeding of the glue to the manifold 33 occurs through pumping systems related to known knowledge or obviously inferable therefrom, and therefore is not shown or described in detail. Also the actuation and control of the movement of the slider can be easily managed with obvious systems, such as tracks, pneumatic linear actuation means, etc., they also not shown. Obviously, embodiments other than the elongated slider will in any case have as preferable and advantageous significant feature the presence of a collection chamber of the glue between scraping means equivalent to the spatulas 34.

[0018] If the methods for applying the glue according to the invention (as said, PVC having similar characteristics to the ones of known systems) are already clear from what is described above, it is important to add and emphasize the resulting advantageous characteristics at the successive hardening step of the PVC. Indeed, the fact that according to the invention, accurately sized PVC points remain exposed on the upper side once the grid 1 with the tiles T is released from the plate 2 (typically, but not necessarily, for the advancement of the grid with the same conveyor system that brought it into the plate area) allows the use of less powerful cooking systems with respect to the traditional system. In particular, given that it is not necessary to bring to temperature the whole mass of the tiles and of the relative support, infrared lamps (of the type already known for drying the PVC in other contexts) may be effectively used, capable of providing the heat required, moreover with a reduced action time. The structure of the apparatus is thus simplified and more compact, in addition to having lower energy consumption.

[0019] Another particularly meaningful advantage is associated with the gluing and the drying with the tiles firmly inserted in the grid. Accordingly, there is the guarantee of a perfect alignment between the tiles and the certainty that they do not move during the whole process, therefore with maximum quality performance. To this end, it is also to be noted how the ridges 12, which on the grid determine the joints between the tiles, act as stop for the pouring of the glue, at proper height determined as seen from an appropriate height of the ridges, thus preventing the PVC from penetrating the whole joint, thus being visible on the front face.

[0020] Again, the silicone grid, or in any case grid of other material with elastic and nonstick properties, allows compensating for any slight differences in calibration between one tile and the next tile, and in any case obtaining the desired closure of the joint.

[0021] It is therefore understood how according to the invention, the preset goals are completely achieved, thus achieving a result that combines, with surprising effectiveness, simplification of the production system, reduction of the consumption and a quality result. Although the most typical application of the invention is the one of tile panels or square tiles, its useful use also in contexts of different shapes cannot be excluded.

[0022] The glue used, that is PVC (more exactly, particles of PVC suspended in a plasticizer such as a phthalic resin), corresponds to the known system. Although to date no alternative glues have been identified that can be applied with similar overall effectiveness, the characteristics of the glue do not in themselves represent a limiting characteristic of the invention, and the PVC may be replaced with different glues, so long as equivalent.

[0023] The present invention was described hereto with reference to a possible illustrative embodiment thereof. It is intended that other embodiments may exist which relate to the same inventive core, all falling within the scope of protection of the claims indicated below.

Claims

1. An apparatus for obtaining a panel product of mosaic tiles arranged in an orderly pattern and mutually joined in an irreversible fashion to form the panel through PVC-like glue points that join respective couples of mutually adjacent tiles, on the side of the back faces of the same tiles, the apparatus comprising at least one stencil member (2) adapted to become superimposed to, and in close proximity of the back face of, said tiles in said orderly pattern, said stencil member (2) comprising an arrangement of guide holes (12) for the deposition of respective glue points between the tiles in correspondence with the holes, and glue distribution and scraping means (3) adapted to distribute and scrape the glue over the stencil member to make the glue drip through said holes (12) deposit between the sides of said tiles, characterized in that it comprises one or more grids (1) made of an elastic, soft and nonstick material, such as silicone, adapted to form said orderly pattern of the tiles, wherein each grid comprises a number of cells (11) the bottom of which is adapted to support the front face of each tile, the cells being separated by ridges (12) having a height with respect to the cell bottom that is preferably comprised between a half and 3/4 of the thickness of the tile, even more preferably about 2/3.

2. The apparatus according to claim 1, wherein said stencil member comprises at least one plate (2), said arrangement of holes comprising a plurality of holes (12) adapted to result in correspondence with couples of two mutually facing sides belonging to different tiles

3. The apparatus according to claim 2, wherein, having said tiles a substantially square shape, said holes (21) are adapted to be positioned in correspondence with the median points of all the couples of two mutually facing sides belonging to different tiles.

4. The apparatus according to claim 3, wherein said holes (21) are circular, with a width of about 1/4 of the side length of the tile.

5. The apparatus according to any of the claims from 2 to 4, wherein said glue distribution means (3) comprise at least one slider (31) movable on said plate over a plane parallel therewith, the slider having a cup-shaped section defining a glue collection and distribution chamber (32), between laminar spatula means (34) that make contact with the plate at free end edges (34a), whereby the spatulas are adapted to carry out the function of scraping elements as the slider moves, the apparatus further comprising glue feeding means for feeding glue to said chamber (32) and means for powering and controlling the movement of said slider (31) over said plate (2).

6. The apparatus according to claim 5, wherein said slider (31) is elongated according to a longitudinal axis (Y) extending between two opposite peripheral sides of the plate (2), and is movable in reciprocating fashion along a direction (X) orthogonal with said axis (Y) of the slider, to sweep over a substantial portion of the plate comprised between said peripheral sides, said glue collection and distribution chamber (32) between said spatulas being in turn elongated according to said longitudinal axis (Y).

7. The apparatus according to claim 6, wherein said free end edges (34a) of said spatulas have a rounded shaping.

8. The apparatus according to any of the previous claims, comprising conveyor means adapted to support said tiles (T) lying on the front face in said orderly pattern, and to transport them towards said stencil member (2) and then away from it, the stencil member being fixed or vertically liftable.

9. The apparatus according to any of the previous claims, comprising or associated with glue cooking means arranged downstream of said stencil member.

10. The apparatus according to claim 9, wherein said cooking means comprise one or more infrared lamps.

11. An apparatus for obtaining a panel product of mosaic tiles (T) arranged in an orderly pattern and mutually joined in an irreversible fashion to form the panel, the method comprising:

- arranging said tiles (T) according to said orderly pattern, lying on the front face and with the back face exposed upwards;

- superimposing to said tiles (T), in close proximity to said back faces, a stencil member (2) comprising an arrangement of guide holes (12) for the deposition of respective glue points between the tiles;

- distributing said glue over said stencil member (2), making it drip through said holes (12) to form said glue points that affect partially said back faces;

- clearing said tiles from said stencil member (2) keeping them in the orderly panel arrangement;

- applying a thermal cooking treatment to said panel with said tiles (T) joined by said glue points,

the method being characterized in that said orderly pattern of the tiles is formed on a grid (1) made of an elastic, soft and nonstick material, such as silicone, wherein each grid comprises a number of cells (11) the bottom of which is adapted to support the front face of each tile, the cells being separated by ridges (12) having a height with respect to the cell bottom that is preferably comprised between a half and 3/4 of the thickness of the tile, even more preferably about 2/3.

12. The method according to claim 11, wherein said holes (21) are positioned in correspondence with couples of two mutually facing sides belonging to different tiles.

13. The method according to claim 12, wherein, having the tiles a square shape, said holes (21) are positioned in correspondence with the median points of all the couples of two mutually facing sides belonging to different tiles.

14. The method according to any of the claims from 11 to 13, wherein said glue distribution provides scraping the glue over said stencil member (2) through a reciprocating motion of one or more laminar spatulas (34).

15. The method according to any of the claims from 11 to 14, wherein said tiles (T) in said orderly pattern are conveyed towards said stencil member (2) and then away from it.

Drawing