MXPA96005130A - Method and apparatus for cladding in combination, by rolling and troquel, with better trimming - Google Patents

Abstract

The present invention relates to a die coating apparatus for coating a fluid coating on a network that moves around a support roll, comprising: a die having an upstream bar, with an upstream flange and a bar downstream with a downstream flange, wherein the upstream flange as a protrusion having a shape corresponding to that of the support roll, and the downstream flange is formed as a sharp edge, a passageway running through the die between the upstream and downstream bars, wherein the passage comprises a groove defined by the upstream and downstream flanges, wherein the coating fluid exits the die from the slot to form a continuous coating projection between the die. upstream die flange and the downstream die flange, and a surface that is coated, and a dosing medium the which removes the excess coating fluid from the surface that is coated, characterized in that the dosing medium is a dosing roller, and the downstream flange has an edge radius of no more than 10 micrometer.

Description

METHOD AND APPARATUS FOR COATING. IN COITOINACTON. BY ROLANDO Y TOQUEL, WITH TECHNICAL FIELD OUTPUT The present invention relates to coating methods. More particularly, the present invention relates to coating methods using a die. ; | ll | l- > l «DH» 13 \ '| ll | l >; OF THE INVENTION U.S. Patent No. 2,681,294 discloses a vacuum method for stabilizing the coating bed for direct extrusion and slip types of dosing coating systems. Such stabilization improves the coating capacity of these systems. However, these coating systems lack sufficient total capacity to provide the thin wet layers, even at very low liquid viscosities, required for some coated products. U.S. Patent No. 4,445,458 discloses an extrusion bed type coating die with a bevelled downward extrusion surface to impose a bonding force on the back side (with REF: 23403 with respect to the process direction) of the bed. coating and to reduce the amount of vacuum needed to maintain the bed. Vacuum reduction minimizes regular surface defects and coating flutes. To improve the coating quality, the obtuse angle of the beveled surface with respect to the groove axis, and the position along the groove axis of the bevel towards the moving network (protruding) and away from the moving network ( placement below) should be used. The optimization results in a high quality required for coating with photosensitive emulsions. However, the thin-film performance necessary for some coated products is lacking. Figure 1 shows a known coating die 10 with a vacuum chamber 12 as part of the dosed coating system. A coating liquid 14 is supplied precisely by a pump 16 to the die 10 for application to a moving network 18, supported by a support roll 20. The coating liquid is supplied through a channel 22 to a manifold 24 for distribution through a slot 26 in the die and the coating on the network 18 in motion. As shown in Figure 2, the coating liquid passes through the slot 16 and forms a continuous coating bed 28 between the initial die boss 30 (with respect to the process direction) and the subsequent die projections 32. (with respect to the process direction), and network 18. The dimensions fx and f2, the width of the projections 30, 32, usually vary from 0.25 to 0.76 in. The vacuum chamber 12 applies a vacuum towards the initial part of the bed to stabilize the bed. Although this configuration works well in many situations, there is a need for a die coating method which improves the operation of known methods.

BRIEF DESCRIPTION OF THE INVENTION The present invention is a die coating apparatus for applying a coating of coating fluid on a surface. The apparatus includes a die having an initial bar with an initial projection and a posterior bar with a posterior projection. The initial projection is formed as a flange and the posterior projection is formed as a sharp edge. A conduit runs through the die between the initial and posterior bars. The conduit has a groove defined by the initial and posterior protrusions, and a fluid coating exits the die from the groove to form a continuous coating bed between the initial die boss, the subsequent die boss and the surface that is coated. A dosing roller removes excess coating fluid. The bed does not move significantly in the space between the flange and the surface to be coated even if the vacuum increases. Alternatively, the apparatus may include a roller on which a coating fluid is initially coated and which contacts the network. An excess coating fluid remover or remover removes excess coating fluid from the roller. A die coats the coating fluid on the roller. The eliminator or remover can be a doctor blade or a dosing roller and the coating liquid on the roller can be transferred by contact to the network. A die coating method according to the present invention includes passing a coating fluid through a groove; improving the coating performance by changing at least one of the relative orientations of the flange and sharp edge; removing the excess coating fluid from the surface to be coated by using a dosing roller; s To read the length of the flange, the edge angle of the rear bar, the angle of attack of the punch between the back bar surface of the casing slot and a tangent plane through a line on the surface to be coated parallel to, and directly opposite, the sharp edge, and a coating separation distance between the sharp edge and the surface to be coated, in combination with each other; and select the slot height, the projection or upper cut and the convergence in combination with each other.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic cross-sectional view of a known coating die. Figure 2 is an enlarged, cross-sectional view of the groove and projection of the die of Figure 1. Figure 3 is a cross-sectional view of an extrusion die of the present invention. Figure 4 is an enlarged cross-sectional view of the groove and the die projection of Figure 4. Figure 5 is a cross-sectional view of the groove and projection similar to that of Figure 4. Figure 6 is a cross-sectional view of an alternative vacuum chamber arrangement.

Figure 7 is a cross-sectional view of another alternative vacuum chamber arrangement. Figure 8 is a cross-sectional view of an alternative extrusion die of the present invention. Figures 9a and 9b are enlarged cross-sectional views of the slot, face and vacuum chamber of the die of Figure 8. Figures 10a and 10b are schematic views of the die of Figure 8. Figure 11 shows the results coating tests which compare the operation of a known extrusion die and the extrusion die of the present invention for a coating liquid with a viscosity of 1.8 centipoise. Figure 12 shows the comparative test results for a coating liquid with a viscosity of 2.7 centipoise. Figure 13 is a data collection from coating tests. Figure 14 is a graph of the constants of the G / Tw lines for an extrusion coating die of the present invention for nine different coating liquids.

Figure 15 is a schematic view of a three roll roller reverse coater, using the die of the present invention. Figure 16 is a schematic view of a two-roll inverse roll coater utilizing the die of the present invention. Figure 17 is a schematic view of an engraving coater using the die of the present invention. Figure 18 is a two-roll extrusion coater using the die of the present invention. Figures 19a, 19b and 19c are cross-sectional views of a contact coater using the die of the present invention. Figures 20a, 20b and 20c are cross-sectional views of a contact coater using the die of the present invention. Figure 20d is a cross-sectional view of a contact coater using the die of Figure 19c.

DESCRIPTION DET? T.T. &GIZV, This invention is a die coating method and apparatus, wherein the die includes a sharp edge and a flange which is positioned to improve and optimize operation. The flange is configured to coincide with the shape of the surface in the immediate area of the coating liquid application. The flange may be curved to coincide with a net passing around a support roll or the flange may be flat to coincide with the free extension of the net between the rolls. Figure 3 shows the extrusion die 40 with a vacuum chamber 42 of the present invention. The coating liquid 14 is supplied by a pump 46 to the die 40 for application to a moving network 48, supported by a support roller 50. The coating liquid is supplied through a channel 52 to a manifold 54 for distribution through a slot 56 and for coating in the motion network 48. As shown in Figure 4, the coating liquid 14 passes through the slot 56 and forms a continuous coating bed 58 between the initial die boss 60, the posterior die boss 62, and the 48 network. Coating can be one of various liquids or other fluids. The initial die boss 60 is part of an initial 64 bar, and the back die shoulder 62 is part of a back bar 66. The height of the slot 56 can be controlled with a U-shaped wedge which can be made of bronze or stainless steel and which can be irregular. The vacuum chamber 42 applies vacuum in the initial part of the bed to stabilize the coating bed. As shown in Figure 5, the initial projection 60 is formed as the curved flange 68 and the rear projection 62 are formed as an acute edge 70. This configuration improves the overall performance with respect to the known die-type coaters. An improvement in operation means allowing operation at increased network speeds and increased coating separations, operating with higher viscosities of coating liquid and generating a thinner wet coating layer thickness. The sharp edge 70 should be clean and free of notches or burrs, and should be straight within 1 micrometer, at 25 cm in length. The edge radius should be no more than 10 micrometers. The radius of the curved flange 68 should be equal to the radius of the support roll 50 plus a minimum, and noncritical, tolerance of 0.13 mm for the separation thicknesses and coating network. Alternatively, the radius of the curved flange 68 may exceed that of the support roll 50 and chocks are used to orient the flange with respect to the network 48. A given convergence C obtained by a flange having the same radius in the support roller by a flange with a radius greater than that of the support roller when handling the flange with the chocks. Figure 5 also shows the geometric operation parameter dimensions for single layer extrusion. The length Lx of the flange 68 curved on the initial bar 64 may vary from 1.6 mm to 25.4 mm. The preferred length Lx is 12.7 mm. The edge angle x of the rear bar 66 can vary from 20 ° to 75 °, and preferably is 60 °. The edge radius of the sharp edge 70 should be between about 2 micrometers to about 4 micrometers, and preferably it should be less than 10 micrometers. The die attack angle A2 between the rear surface bar 66 of the facing groove 56 and the tangent plane P through a line on the net surface 48 parallel to and directly opposite the acute edge 70 may vary from 60 to 60. ° up to 120 ° and preferably it should be 90 ° -95 °, for example, 93 °. The coating gap Gl is the perpendicular distance between the sharp edge 70 and the net 48. (The coating gap Gt is measured at the sharp edge, but is shown in some figures separated from the sharp edge for clarity. position of Gl in the drawings -and due to the curvature of the net which increases the separation as it moves away from the sharp edge- the separation is measured at the sharp edge). The height H of the slot can be between 0.076 mm to 3.175 mm. The upper projection O is a positioning of the acute edge 70 of the rear bar 66, with respect to the rear edge 72 of the flange 68 curved on the initial bar 64, in a direction towards the network 68. The upper projection or cut is also it can be seen as a retraction of the rear edge 72 of the curved rebox away from the net 48, with respect to the acute edge 70, for any given coating gap G1.The projection may vary from 0 mm to 0.51 mm, and the fittings At the opposite ends of the die, they should be 2.5 micrometers apart, and a precision mounting system is required for this coating system, for example, to achieve a precise projection uniformity. the hands of the clock, as shown in Figure 5, an angular positioning of the curved flange 68 moving away from a position parallel to (or concentric with) the network 48, with the rear edge 72 which is in the center of rotation. Convergence can vary from 0o to 2.29 °, and the operating space at opposite ends of the die slot can be within 0.023 ° to each other. The height of the groove, the projection and the convergence, as well as the properties of the fluid such as viscosity, affect the operation of the apparatus and method of die coating. From the general operating point of view, for liquids with a viscosity range of less than 1,000 centipoise, it is preferred that the slot height be 0.18 mm, the projection or upper cut is 0.076 mm, and the convergence is 0.57. °. The operating levels by using other slot heights can be close to them. You can also find performance advantages at viscosities above 1,000 centipoise. By maintaining the convergence at 0.57 °, some other groove heights and optimal projection or top cut combinations are as follows: Slot Height Projection 0. 15 mm 0.071 mm 0.20 mm 0.082 mm 0. 1 mm 0.100 mm 0.51 mm 0.130 mm In the liquid viscosity range indicated above, and for any given convergence value, the optimum projection value appears to be directly provide to the square root of the slot height value. Similarly, for any given slot height value, the optimal projection value appears to be inversely proportional to the square root of the convergence value. As shown in Figure 6, the vacuum chamber 42 can be an integral part of, or be attached to the initial bar 64, to allow a repeatable vacuum system gas flow. The vacuum chamber 42 is formed by the use of a vacuum bar 74 and can be connected through an optional vacuum restrictor 76 and a vacuum manifold 78 to a vacuum source channel 80. A curved vacuum flange 82 can be an integral part of the initial bar 64, or it can be part of the vacuum bar 74, which is fixed to the initial bar 64. The vacuum flange 82 has the same radius of curvature as the curved flange 68. The curved flange 68 and the vacuum flange 82 can be finished grinding together so that they are "in lines" with each other. The vacuum flange 82 and the curved flange 68, therefore, have the same convergence C with respect to the network 48. The gap G, of vacuum flange is the distance between the vacuum flange 82 and the network 48 in the bottom edge of the vacuum flange and is the sum total of the coating gap Gx, the projection O and the displacement caused by the convergence C of the curved flange 68. (Regardless of the position of Gx in the drawings, the spacing is the perpendicular distance between the lower edge of the vacuum flange and the network). When the vacuum flange gap G2 is large, there is an excessive inrush of ambient air into the vacuum chamber 42. Although the vacuum source may have sufficient capacity to compensate and maintain the vacuum pressure level specified in the chamber 42 of vacuum, the irruption of air can degrade the operation of the coating. In Figure 7, the vacuum flange 82 is part of a vacuum bar 74 which is attached to the initial bar 64. During manufacture, the curved flange 68 ends with the "rectified" C-convergence. The vacuum bar 74 is then joined, and the vacuum flange 82 is ground finish by using different grinding center, for example, the vacuum flange 82 is parallel to the network 48, and the flange gap G2 is empty is equal to the separation G? of coating when the desired projection value is established. The length L2 of the vacuum flange can vary between 6.35 mm and 25.4 mm. The preferred length L2 is 12.7 mm. This embodiment has a greater total coating performance capability in difficult coating situations compared to the embodiment of Figure 6, but a finishing grinding is always required for a specific group of operating conditions. In this way, insofar as the coating gap Gx or the projection 0 changes, the gap flange gap G2 can move away from its optimum value. In Figures 8 and 9, the initial bar 64 of the die 40 is mounted on an initial bar setter 84, and the vacuum bar 74 is mounted on a vacuum bar setter 86. The flange 68 curved in the initial bar 64 and the vacuum flange 82 of the vacuum bar 74 do not connect directly to each other. The vacuum chamber 42 is connected to its vacuum source through the vacuum bus 74 and the setter 86. The mounting and positioning of the vacuum bus 74 are separated from those of the initial bus 64. This improves the performance of the die and allows a precise and repeatable gas flow of the vacuum system. The rugged configuration of the vacuum bar system also helps to improve performance, compared to the known systems. In addition, this configuration for vacuum bar 74 can improve the operation of other known coaters, such as slot, extrusion and slide coaters. A flexible vacuum seal strip 88 seals between the initial bar 64 and the vacuum bar 74. The gap G, between the vacuum flange 82 and the network 48 is not affected by changes in the coating gap Gx, the O projection or the C convergence, and can be maintained at this optimum value continuously during the coating. The G2 gap of vacuum flange can be set within the range from 0.076 mm to 0.508 mm. The preferred value for the G2 separation is 0.15 mm. The preferred angular position for the vacuum flange 82 is parallel to the network 48. During the coating, the vacuum level is adjusted to produce a coated layer of the best quality. A typical vacuum level, when coated with a coating liquid with 2 centipoise to 6 micrometers wet layer thickness and a network speed of 30.5 m / min, is 51 mmH20. By decreasing the thickness of the wet layer, the viscosity increases or by increasing the network speed it may require higher vacuum levels exceeding 150 mmH20. The dies of this invention show lower satisfactory minimum vacuum levels and higher satisfactory maximum vacuum levels compared to known systems, and in some situations they can operate with a vacuum 0, when the known systems can not do so.

Figures 10a and 10b show certain placement adjustments and the vacuum chamber enclosure. An adjustment of the projection moves the rear bar 66 relative to the initial bar 64 so that the acute edge 70 moves toward or away from the net 48 with respect to the rear edge 72 of the curved flange 68. By adjusting the convergence the initial bar 64 and the rear bar 66 are rotated together, about an axis running through the rear edge 72, so that the curved flange 68 moves from the position shown in Figure 10, moving away of, and parallel to, the network 48, or backward, to the parallel part. An adjustment of the coating gap is transferred to the initial bar 64 and to the rear bar 66 by joining them to change the distance between the sharp edge 70 and the network 48, while the vacuum bar remains stationary in its mounting or support 86, and the vacuum seal tape 88 is flexed to prevent air leakage during adjustments. The air leak at the die ends in the vacuum chamber 42 is reduced by the end plates 90 attached to the ends of the vacuum rod 74 which overlie the ends of the initial bar 64. The vacuum bar 74 is 0.10 mm to 0.15 mm larger than the initial bar 64 so that, in a centered condition, the gap or empty space between each end plate 90 and the initial bar 64 varies from 0.050 mm to 0.075 mm. During the coating, an unexpected operation characteristic has been observed. The bed does not move significantly between the space between the curved flange 68 and the moving net 48, even when the vacuum increases. This allows using higher vacuum levels compared to those that are possible with known extrusion coaters, and correspondingly provides a higher level of performance. Even when vacuum is not required or very little is required, the invention shows improved performance with respect to known systems. The fact that the bed does not move significantly in the space between the curved flange 68 and the net 48 also means that the "spill" or runoff effect on the support roll 50 at the subsequent coating weight does not differ from the known extrusion coaters. Figure 11 shows a graph of the coating test results which compare the operation of a known extrusion die with an extrusion die of this invention. In the tests, a coating liquid of 1.8 centipoise and containing an organic solvent is applied to a network of flat polyester film. The criterion of operation is the minimum wet layer thickness in four different coating separation levels for each of the two coating systems, with respect to the speed range of 15 to 60 m / min. The curves A, B, C and D use the prior art die and are carried out with coating separations of 0.254 mm, 0.203 mm, 0.152 mm and 0.127 mm, respectively. The curves E, F, G and H use a die according to this invention to the same respective coating separations. The lower wet thickness levels for this invention, as compared to the prior art die, are easily visible. Figure 12 shows comparative test results for a similar coating liquid, with a viscosity of 2.7 centipoise, at the same coating separations. Once again, the operating advantage for this invention is clearly visible. Figure 13 is a data collection from coating tests in which liquids, at seven different viscosities and containing different organic solvents, are applied to flat polyester film webs. The results compare the operation of the extrusion coater of the prior art (PREVIOUS) and that of this invention (NEW). The operating criteria are mixed. The operating advantages for this invention can be found in terms of the network speed (Vw), the thickness of the wet layer (Tw), the coating separation, the vacuum level or a combination of these parameters. A measure of the performance of the coater is the ratio of coating separation to the thickness of the wet layer (G / Tw), for a particular coating liquid and network speed. Figure 14 shows a series of constant G / Tw lines and viscosity values of an extrusion die of this invention, for nine different coating liquids. The liquids are used as a coating on a flat polyester film base at a network speed of 30.5 m / min. Some viscosity values appear to be out of order, due to the effect of other coating capacity factors. Four additional lines of operation have been added after calculating the G / Tw values for a network speed of 30.5 m / min from Figures 11 and 12. From the top to the bottom, the continuous lines of operation are G / Tw for 2.7 centipoise and 1.8 centipoise liquids coated with a known extrusion die, and G / Tw for 2.7 centipoise and 1.8 centipoise liquids coated with an extrusion die of this invention. The lines for this invention represent G / Tw values higher than those of the lines for the prior art coating die. In addition, the lines for this invention are close to the lines that are established with constant G / Tw, which averages 18.8 and 16.8, respectively. The lines of the known coater show a considerably higher G / Tw variation with respect to its length. The invention has a fairly improved operating characteristic for maintaining a coating bed with low wet thickness values, compared to known systems. The coating dies of this invention can be used in high performance liquid feed devices for roller and contact coaters. Figure 15 shows a three roll inverse roller coater that uses an extrusion die 40 to supply coating liquid 14 to a melt roll 330. Because the surface of the melt roll 330 passes the die 40 in a downward direction, the die 40 is inverted, and the vacuum chamber 42 is above the groove and the coating bed. This does not affect the performance of the coating. The dosing roller 332 removes any excess coating liquid, which leaves a precise coating on the coating roll 330. A doctor blade 334 removes the excess coating liquid from the dosing roller 332 and drops it into a container 336 returning liquid for recirculation. Meanwhile, a bed-separating action transfers part of the coating liquid from the melt roll 330 to the network 48 that moves around the support roll 50. After the bed is divided, a second doctor blade 338 cleans the remaining coating liquid from the melt roller 330 and advances it to the recirculation vessel 336. Alternatively, the support roll 50 may be covered with rubber so that the melt roll 330 can make contact with the network and transfer all of the coating liquid in this area to the network. The second doctor blade 338 can subsequently clean any liquid from the melt roller 330 which is outside the width of the network. Figure 16 shows a two-roll reverse roll coater, which uses an extrusion die 40 for feeding coating liquid to the surface of the net 48 that moves around the support roll 14, which is a melt roll rolled The dosing roller 332 removes any excess coating liquid from the surface of the network 48, which leaves the wet coating layer accurate, desired. The doctor blade 334 cleans the excess coating liquid from the dosing roller 332 and directs it to the recirculation container 336. The use of this system in one example increases the allowable vacuum range from 5.08 mm to more than 254 mmH20, and increases the liquid feed coating separation from 0.10 mm to 0.36 mm, thus improving stability and practically eliminating stretch marks. Figure 17 shows an engraved hole coater utilizing an extrusion die 40 for feeding coating liquid to the surface of a spline roll 340. The die 40 has its vacuum chamber 42 above its coating groove. A doctor blade 342 removes the excess coating liquid from the fluted pattern so that the desired amount is transferred to the net 48 and moves around the rubber-coated support roll 314. The excess coating liquid recirculates through the container 336. This method of feeding coating liquid to the surface of a fluted roller can also be used for other forms of engraved hole coating such as inverse, offset and differential. Figure 18 also shows a two roll extrusion coater utilizing an extrusion die 40 for feeding coating liquid to the surface of the melt roll 330, with stability from the vacuum chamber 42. The coating liquid layer is thin and precise so that a dosing roller is not required. The bed separation occurs directly in the network 48 that moves around the support roll 314. A doctor blade 338 removes the excess coating liquid from the melt roll 330 and sends them for recirculation through the container 336. Alternatively, the support roll 50 may be coated with rubber so that the melt roll 330 can make contact with the network and transfer all the coating liquid in this area to * the network. The second doctor blade 338 subsequently cleans any liquid from the melt roller 330 which is outside the width of the network. Figure 19a shows a contact coater in which the extrusion die 40 delivers a coating liquid through a manifold 54 and a slot 56 to a transfer roller 344 such as a pivot or shaft having a diameter varying from 25.4 mm to 50.8 mm. The coating bed is stabilized by the vacuum chamber 42. The coating liquid on the transfer roller 344 is transferred by contact to form the coated layer on the network 48. The small diameter of the transfer roller 344 has a small contact transfer area, and improves the stability of the network with respect to a larger transfer roller by reducing the undulation of the network and the transverse tension marks. The surface of the transfer roller 344 can be, for example, smooth, polished, medium polishing, subjected to constant or scratched shot blast. Figure 19b shows a contact coater in which the extrusion die 40 with a vacuum chamber 42 supplies coating liquid to the surface of a contact transfer roller 344. The roller 344 has a larger diameter than the pivot of Figure 19a. The coating liquid is transferred by transfer to form the coated layer on the network 48. Figure 19c shows a contact coater in which the sliding coating die 310 applies a coating to the surface of a transfer roller 344 as a coating. by contact. The transfer liquid is transferred by contact to form the coating layer on the network 48. Figure 20a shows a contact coater in which a double layer extrusion die 100 supplies two coating liquids 116, 124 through the 118 channels, 126 to the surface of a pivot, such as a transfer roll 344 having a diameter ranging from 25.4 mm to 50.8 mm. The two coating liquids on the transfer roller 344 are transferred to form two coated layers on the network 48. Figure 20b shows a contact coater in which a double layer extrusion die 100 delivers a coating liquid to a roller of transfer by contact. The roller 344 has a larger diameter than the roller of Figure 20a. The two coating liquors 116, 124 are fed through separate manifolds and two separate slots to coincide with the coating bed. The two coating liquids are transferred to the network forming the wet coating layers. Figure 20c shows a contact coater in which a double layer extrusion die 100 delivers a coating liquid to a contact transfer roller 344. The two coating liquors 116, 124 are supplied through two manifolds, but only one groove, which fits inside the die. The two coating liquids on the surface of the transfer roller 344 are transferred to form the two coating layers on the network 48. Figure 20d shows a contact coater in which a multi-layer coating version of the die 220 of the Figure 19c feeds four coating liquids onto the surface of the transfer roller 344. The four liquids 116, 124, 346, 348 are fed through the die 100, to the lower sliding surfaces 236 to form four layers on the surface of the transfer roller 344. These layers are transferred to form four coated layers on the network 48. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects a that it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (7)

REGTNDICACIQNES

1. A die coating apparatus for coating a coating fluid on a network that moves around a support roll, characterized in that it comprises: a die having an initial bar (with respect to the process direction) with a initial projection, and a posterior bar (with respect to the process direction) with a posterior projection, wherein the initial projection is formed as a ledge, and the posterior projection is formed as a sharp edge; a conduit running through the die between the initial and posterior bars, wherein the conduit comprises a groove defined by the initial and posterior protrusions, wherein the coating fluid exits the die from the groove to form a coating bed. continuous between the initial die boss, the subsequent die boss and the surface to be coated; a metering roller which removes the excess coating fluid from the surface to be coated.

2. A die coating apparatus for coating a coating fluid on a network, characterized in that it comprises: a roller on which a coating fluid is initially coated and which subsequently transfers the coating fluid to the network; means for removing excess coating fluid from the roller, wherein the removal or removal means contacts the roller to remove excess coating fluid; a die for coating the coating fluid on the roller and having an initial bar with an initial projection, and a back bar with a posterior projection, wherein the initial projection is formed as a flange, and the posterior projection is formed like a sharp edge; and a conduit running through the die between the initial and posterior bars, wherein the conduit comprises a groove defined by the initial and posterior protrusions, wherein the coating fluid exits the die from the groove to form a continuous coating bed between the initial die boss, the subsequent die boss and the surface to be coated.

3. The apparatus according to claim 2, characterized in that the removal or removal means comprises a doctor blade.

4. The apparatus according to claim 2, characterized in that the removal means comprises a metering roller.

5. The apparatus according to claim 3, characterized in that the coating liquid in the roller is transferred by contact to the network.

6. A die-coating method, characterized in that it comprises: passing the coating fluid through a slot defined by an initial bar with an initial projection, and a back bar with a posterior projection, wherein the initial projection is formed as a flange and the posterior protrusion is formed as a sharp edge; improve coating performance by changing the orientation of one of the flange or sharp edge; removing the excess coating fluid from the surface to be coated by using a dosing roller which contacts the surface to be coated; select a length L of the flange, an angle Edge ax of the rear bar, an angle of attack of die between the surface of the rear bar of the facing groove and a plane tangent across the line on the surface to be coated parallel to, and directly opposite to the sharp edge, and a distance G of coating separation between the sharp edge and the surface to be coated, in combination with each other; and selecting a slot height H, a projection or upper cut 0 and a convergence C in combination with each other.

7. The method according to claim 6, characterized in that it additionally comprises the step of applying vacuum to the initial part of a coating bed formed to stabilize the bed, in which the bed does not move significantly in the space between the flange and the surface to be coated, even if the vacuum increases.