FR2692818A1 - Coater or impregnator of liquid or semi-solid products on moving substrates - Google Patents

Abstract

The coater/impregnator (1) has an applicator (4) to apply a coat (5) on a substrate (2) face (6), which moves continuously over the applicator. The applicator (4) reservoir (7) has a perforated zone (8), which the substrate (2) wraps round, in contact with the face (6). The applicator perforations (8) join internal connections to a product supply chamber, with surface and/or permeability adjustable.Wipers (16) may be placed after the applicator to equalise the product coating on the substrate. The reservoir (7) may be a fixed cylinder with two longitudinally adjustable supply pipes, defining the moving substrate coating or impregnation area.

Description

 The invention relates to a device for coating and / or impregnating a liquid or pasty product on a sheet of material in continuous movement.

 It will in particular find its use in many technical fields using as raw material plies of flexible material, such as paper, cardboard, textile, or even plastic, which is scrolled at greater or lesser speed, and where it is necessary to treat one side of the sheet while it is running in order to deposit on it a layer of liquid or pasty product, such as for example ink, glue, paint, or more generally any technical product, decoration or treatment.

 Furthermore, the invention will find its application in the equipment of such machines producing webs of material in continuous movement.

 For example, in the field of the production of corrugated cardboard, it is customary to secure the paper strips with the aid of glue. More precisely, an adhesive film is deposited on one of the faces of these strips, in a regular manner, with a determined quantity, then the two strips are pressed and dried to form the sheet of cardboard.

 In this regard, devices are known such as wetting rollers constituted by a cylinder dipping in a bath of the product to be applied. The main drawbacks of such devices lie in the difficulty of metering the amount of product to be deposited, and in the impossibility of carrying out partial treatments of width less than that of the cylinder.

 Spraying devices are also known which allow adjustment of the flow rate by means of spray nozzles. However, in these devices, it is difficult to adjust the uniformity of the deposit made. In addition, the use of pasty products is completely excluded.

 There is also known a device for applying a liquid or pasty product to a continuously moving web, comprising means for depositing a film of liquid or pasty product on a surface of the web to be treated and means for supplying the product.

 More specifically, the device comprises a reserve of product, constituted by a flexible plastic sheet pressed above the traveling web by means of a pressing blade, arranged across the web and forming the lower part of the tank. .

 To authorize the deposition of the product on the moving web, the said plastic sheet has a rectangular window whose dimensions define the width of the coating and the amount of product deposited.

 Although this device is satisfactory in certain cases, it is however ill-suited to high production rates and its reliability depends on the tension in the sheet and the quality of the application of the window on the sheet.

 The object of the present invention is to provide a device for coating and / or impregnating a liquid or pasty product on a sheet of material in continuous movement, which makes it possible to overcome the aforementioned drawbacks and which is not an obstacle to production at high speed. .

 One of the aims of the present invention is to propose a coating and / or impregnating device which can be inserted in lines of machines for producing webs of material in continuous movement, and which has a robust and reliable construction allowing its operation at very high frame rates.

 One of the aims of the present invention is to propose a device for coating and / or impregnating a liquid or pasty product which makes it possible to precisely control the deposition of said product on the sheet of moving material, as well as its geometry, without however having to modify the structure of the elements used.

 Another object of the present invention is to present a device for coating and / or impregnating a liquid or pasty product which, thanks to its structure, allows easy operation control and also the automation of its settings.

 Another object of the present invention is to propose a coating and / or impregnating device which does not slow down the production rates if, by its adjustments, it is no longer in the working position.

 Other objects and advantages of the present invention will appear during the description which follows which is however given only for information and which is not intended to limit it.

 According to the present invention, the device for coating and / or impregnating a liquid or pasty product on a sheet of material in continuous movement, comprising applicator means for depositing a layer of said product at least partially on one face of said sheet, is characterized in that the applicator means are constituted by a reserve having a perforated area, brought into contact with the face to be coated and / or impregnated, the permeability and / or the surface of which are adjustable.

 In a first embodiment, said reserve is in the form of a cylinder pierced on a part of its envelope with a set of orifices opening outwardly and communicating internally with a product supply chamber.

 According to another embodiment, the reserve is in the form of a polyhedron, instead of a cylinder, one of the faces of which has the said set of orifices.

 The invention will be better understood if reference is made to the following description and to the accompanying drawings which form an integral part thereof.

 Figure 1 shows schematically in perspective a first embodiment of the coating and / or impregnating device of the present invention.

 Figure 2 shows a cross-sectional view of the applicator means shown in Figure 1 in a closed position.

Figure 3 shows a longitudinal section of the applicator means shown in Figure 2 along the axis
III-III.

 Figure 4 shows a cross-sectional view of the same applicator means as those illustrated in Figure 2 but in a working position allowing the coating and / or impregnation.

 FIG. 5 shows a view in longitudinal section of the applicator means shown, in a working position, in FIG. 4 along the axis V-V.

 FIG. 6 schematically shows a second embodiment of the coating and / or impregnating device of the present invention.

 Figure 7 shows an exploded view of the applicator means in a first embodiment.

 FIG. 8 shows a perspective view with partial section of the applicator means of FIG. 6.

 The invention relates to a device for coating and / or impregnating a liquid or pasty product on a sheet of material in continuous travel.

 Although more especially developed within the framework of the equipment of machines for the manufacture of corrugated cardboard, the present invention is in no case limited to such an application and in general will find its use in any type of field using as raw material plies of flexible material such as paper, cardboard, fabric or plastic, which are scrolled at high speed, and where it is necessary to treat one side of the ply during its scrolling, in order depositing on it a film of liquid or pasty product, such as for example ink, glue, an impregnator, or any other technical, treatment or decoration product.

 FIG. 1 schematically shows in perspective a first embodiment of the device 1 of the present invention in which there is located in 2 a sheet of material in continuous movement, simulated by the arrows 3.

 The device comprises applicator means 4 for depositing a layer 5 of liquid or pasty product at least partially on one face 6 of the sheet, as shown in FIG. 1.

 More specifically, according to the invention, these applicator means 4 are constituted by a reserve 7 having a perforated area 8, brought into contact with the face 6 to be coated and / or impregnated, whose permeability and / or surface are adjustable.

 The structure of this reserve is shown in more detail in Figures 2 and 3. In this case, the reserve 7 is in the form of a cylinder, fixed relative to the running movement 3 of the web 2, around which the said ply 2 is deflected, as shown in particular in FIGS. 1 and 2.

 Furthermore, the cylinder 7 has on a part of its envelope 8 a set of orifices 9 opening outwardly and communicating internally with a product supply chamber 10.

 In addition, the reserve 7 has, in its inner part, a radial obturator tube 11, capable of controlling the radial permeability of the set of orifices 9 and consequently the thickness of the layer 5 deposited.

 More specifically, in the illustrated embodiment, the reserve 7 is constituted by a set of coaxial tubes adjusted to one another. A first outer tube 12 is pierced with a multitude of radial orifices 9 and regularly spaced apart by a step marked zip1 "in the longitudinal direction and" P2 "in the radial direction.

 By way of example, when the envelope of the cylinder 12, of diameter 200 for example, is developed, good results have been obtained by making orifices with a diameter of 25 mm alternated in staggered rows with a pitch p1 of 20 mm and a pitch p2 of 26 mm. These orifices can be cylindrical or of flared shapes to increase the surface of the orifice in contact with the sheet as shown in the figures.

 It has also been noted that it was sufficient to provide this set of orifices 9 on the periphery of the cylinder, and for example, taking into account the aforementioned dimensions, rows of five orifices and rows of four are alternated. However, this information is given for information only and it could well be envisaged to use other dimensional characteristics.

 Then, inside this first tube 12, a second tube 11 is adjusted, which is itself pierced with a multitude of annular grooves 13 and parallel to each other, and spaced apart from said step p, ".

 Under these conditions, these grooves are placed opposite the corresponding rows of orifices 9, and thanks to a free mounting in rotation of the second tube 11 relative to the first tube 12, we will more or less obscure the openings 9 in each row.

 By choosing the illustrated arrangement, over a half diameter, it is then possible by rotation of the tube 12 either to completely obscure the holes 9, as shown in FIGS. 2 and 3, or to let them communicate with the supply chamber 10 from 0 to 100 % as particularly shown in Figures 4 and 5.

 This arrangement will make it possible to adjust the radial permeability of the perforated zone 8 brought into contact with the face to be coated and / or to be impregnated and, consequently, to control the thickness of the deposited layer.

 This being so, in order to be able to control the transverse permeability of the set of orifices 9, and consequently the width of the deposited layer 5, as particularly shown in FIGS. 1 and 5, the reserve 7, present in its internal part, minus a transverse obturator tube 14.

 This third tube 14, fitted in the second tube 11 defines an internal conduit constituting said product supply chamber 10. Furthermore, this third tube is mounted so that it can be moved in longitudinal translation relative to the second tube 11.

 Furthermore, as shown in FIGS. 3 and 5, in order to be able to adjust the width and act independently on the right and left selvedges 15 of the deposited layer 5, the transverse obturator tube 14 will advantageously consist of two half tubes 141 and 142 movable transversely in the second tube 11, in order to be able to close off all the grooves 13, as shown in FIG. 3, or some of them as shown in FIG. 5, or to allow free passage over all the orifices.

 However, in order to equalize the deposition of said product on the sheet, the device of the present invention further comprises, placed downstream of the applicator means 4, means for scraping the coated sheet.

 In an advantageous embodiment, and as particularly shown in Figures 2 and 4, these means 15 are constituted by a bar 16 called "Meyer", known to those skilled in the art.

 This bar is for example constituted by a wire wound in a spiral and welded which is rotated in the opposite direction of the advancement of the sheet as illustrated in the figure. In addition, this bar is pressed on the sheet, by means of an air chamber 17 for example.

 Thus, by an adequate adjustment of the scraping means 15, the overflow 18 is discharged laterally towards the outside of the sheet to be treated.

 It should be noted that the device of the present invention is also fitted with various pipes and stop valves, making it possible to inject into the tube 141, for example, the product to be deposited on the sheet, which is then channeled by the inner duct of the second tube 11 then is evacuated through grooves 13 and orifices 9 towards the strip as the arrows 19 in FIG. 5 simulate.

 It should be noted that the overflow can be evacuated through the tube 14z to return to the tank. This arrangement can also be used to wash the interior of the cylinder 7.

 FIGS. 6 to 8 show a second embodiment of the device of the present invention in which the reserve 7 is in the form of a polyhedron 20, one of the faces 21 of which is brought into contact with the web 2 as it travels 3, and has a set of orifices 22 opening outwardly and communicating internally with a product supply chamber.

 In this case, as shown particularly in FIG. 7, the product is supplied with orifices 23 distributed over the upper surface and opening into the interior cavity 24 of said polyhedron.

 In the mode shown in the figures, the polyhedron is in the form of a tube 20 of rectangular section, inside which one or more shutters 25-30 are provided sliding.

 These shutters 25-30 are capable of sliding longitudinally in the interior chamber 24 of the tube 20 to control the longitudinal permeability, and consequently the thickness of the deposited layer, and / or the transverse permeability, and consequently the width of the layer. filed.

 Indeed, as in the previous embodiment, by the play of the shutters 25-30, one can on the one hand select a number of holes 22 in the direction of the step "P2" and on the other hand play on the width to coat in the direction of the zip1 "step as shown in particular in Figure 8.

 Furthermore, the perforated zone 21 of the reserve 20 is applied to the moving web with a back pressure, simulated in FIG. 6 by the presence of the spring 31 and the lower anvil 32. However, other means of back pressure could be considered.

 In addition, similarly to the first embodiment, the device can be equipped, downstream of the applicator means, with scraping means, identified here 33, and constituted for example by a flexible blade rubbing the ply 2 at the outlet of the applicator 7, as shown in Figure 6.

 However, one could also provide a "Meyer" bar with back pressure on the other side of the sheet.

 Naturally, other implementations of the present invention, within the reach of those skilled in the art, could have been envisaged without departing from the scope of the present application.

Claims (10)

 1. Device (1) coating and / or impregnating a liquid or pasty product on a sheet (2) of continuously moving material (3), comprising applicator means (4) for depositing a layer (5) of said product , at least partially on one face (6) of said ply, characterized in that the applicator means (4) consist of a reserve (7) having a perforated zone (8; 21) brought into contact with the face (6) to be coated and / or impregnated, whose permeability and / or surface are adjustable.  2. Device according to claim 1, characterized in that said reserve (7) is in the form of a cylinder (12), fixed, around which said ply (2) is deflected, having on a part of its envelope a set of orifices (9) opening outwardly and communicating internally with a product supply chamber (10).  3. Device according to claim 2, characterized in that the said reserve (7, 12) has, in its inner part, a tube (11) radial obturator, capable of controlling the radial permeability of the set of orifices ( 9) and consequently the thickness of the deposited layer.  4. Device according to claim 2, characterized in that said reserve (7, 12) has, in its inner part, at least one tube (14; 14 ,, 142) transverse obturator capable of controlling the transverse permeability of the 'set of holes (9) and therefore the width of the deposited layer.  5. Device according to claims 1 to 4, characterized in that said reserve (7, 12) is constituted at least by a set of three coaxial tubes (11, 12, 14); the first outer tube (12) pierced with a multitude of radial orifices (9) is regularly spaced, the second (11) fitted in the first (12), pierced with a multitude of annular grooves (13), mutually parallel and spaced apart by a pitch corresponding to the orifices (9), capable of being moved in rotation relative to the first tube (12); the third (14; 14 ,, 142) fitted in the second (11), defining an internal conduit constituting the said product supply chamber (10), and capable of being displaced in longitudinal translation relative to the second tube (11 ).  6. Device according to claim 1, characterized in that said reserve (7) is in the form of a polyhedron (20), one of the faces (21) of which is brought into contact with the web (2) in movement (3), and has a set of orifices (22) opening externally and communicating internally with a product supply chamber.  7. Device according to claim 1, characterized in that said reserve (7, 20), is in the form of a tube of rectangular section, inside which are provided sliding one or more shutters (25- 30) capable of controlling the longitudinal permeability, and consequently the thickness of the deposited layer, and / or the transverse permeability, and consequently the width of the deposited layer.  8. Device according to claim 6, characterized in that the perforated area (21) of the reserve (20) is applied to the sheet in movement with a back pressure (31, 32).  9. Device according to claim 1, characterized in that it comprises, placed downstream of the applicator means, means (15, 16, 17; 33) for scraping the coated web to equalize the deposition of said product.  10. Device according to claim 9, characterized in that the means (15) of adjustment consist of a bar (16) of "Meyer", pressed on the web (2) via an air chamber (17).