System for coating a continuous sheet

Abstract

A system for coating a continuous sheet (1) comprising an application roller (10) for applying a coating on the sheet (1) when the sheet (1) is pressed against the application roller (10) by an application pressure element (11), a smoothing roller (20) for smoothing the coating applied on the sheet (1) by contact of the smoothing roller (20) with the coating when the sheet (1) is pressed against the smoothing roller (20) by a smoothing pressure element (21), the application pressure element (11) and the smoothing pressure element (21) being independently movable in order to press the sheet (1).

Description

Technical Field

[0001] This invention relates to the roller application of coating products to sheets or layers of material in a continuous process. In particular, this invention relates to the preparation of continuous sheets for coating component parts (such as panels or shapes) of furniture by means of adhesives or glues used as coating products. Background Technology

[0002] Currently, roller application systems for applying coatings or layers of coated products (e.g., glue or adhesive) to continuous sheets are well known. In these roller application systems, the application roller applies the coating onto the sheet as the sheet is pressed against the application roller by an application pressure element in the transfer area of ​​the coated product.

[0003] These roller application systems make it possible to achieve a uniform distribution of the coating on the sheet. This is useful for adhesive application, where the coating product applied to the sheet is a glue or adhesive, because it allows defects that can occur due to variations in the quality of the applied glue when the sheet is fastened to the base portion.

[0004] In so-called high-gloss coatings, high-gloss sheets are used; in other words, the high-gloss sheets are made of materials with a surface gloss similar to that of a mirror. Alternatively, in transparent coatings, transparent sheets are used, where any minute defects are more easily visible. For this reason, uniform application of the adhesive is particularly important. Patent document ES 2394833 describes a roller application system for applying adhesive to a continuous sheet for applying high gloss.

[0005] In view of the known solutions currently available, the object of the present invention is to provide a system for coating continuous sheets, which enables the obtaining of uniform coatings in an improved manner, and is particularly practical for high-gloss, transparent or similar coatings, wherein, due to their characteristics, they make it possible to easily see application defects. Summary of the Invention

[0006] In order to achieve this objective and solve the technical problems discussed to date, in addition to providing additional advantages that can be subsequently derived, the present invention relates to a system for coating a continuous sheet, the system comprising an application roller for applying a coating onto the sheet when the sheet is pressed against the application roller by an application pressure element.

[0007] Furthermore, the coating system according to the invention includes a smoothing roller, which is used to smooth the coating applied to the sheet by contact between the smoothing roller and the coating when the sheet is pressed against the smoothing roller by a smoothing pressure element.

[0008] This continuous arrangement of the application roller and the smoothing roller makes it possible for the smoothing roller to provide the required greater uniformity to the applied coating once the coating has been deposited on the continuous sheet by the application roller.

[0009] According to the invention, the applying pressure element and the smoothing pressure element are capable of moving independently to press the sheet; in other words, they can independently approach the corresponding applying roller or smoothing roller. This capability for independent movement makes it possible to provide an optimized uniform or smooth coating because it allows the applied coating to become uniform or smooth independently of the applied coating by adjusting the uniformity or smoothness.

[0010] Preferably, the pressure-applying element and / or the smoothing pressure element are adjustable in their movement. In the context of this invention, "adjustable in movement" is understood to mean that the pressure element can move from an initial position to a plurality of selected different endpoint positions, particularly endpoint positions in which the pressure element applies different pressures against the respective application roller or smoothing roller.

[0011] The adjustment of the movement of the pressure element makes it possible to adjust the desired uniformity of the coating. In this sense, it is designed so that the pressure element can move continuously, thereby enabling more precise adjustment of its movement and thus more precise adjustment of the uniformity of the coating applied to the sheet.

[0012] Additionally, preferably, the system may include a movement controller to control the movement of the pressure-applying element and / or the smoothing pressure element. In the context of this invention, control of movement, particularly control of the adjustment of movement, is understood as executing movement according to a program or instructions stored by the controller. In this manner, it is possible to simplify or accelerate the operation of the system to obtain an optimal uniform coating.

[0013] Similarly, control can be performed automatically, for example, by means of processing the system's operating parameters via a controller. These operating parameters include, for example, the basis weight of the coated product, characteristics of the sheet or component portion to be covered (e.g., porosity of the sheet or panel to be glued, thickness of the sheet to be glued, etc.), the sheet's advance speed or tension, the advance speed of the component portion, etc. This control can be performed without stopping the system to regulate the movement of the pressure element, or even in real time. For example, advantageously, to obtain an optimal uniform coating for a higher applied coating basis weight, it is possible to select a lower pressure on the smoothing pressure element compared to a lower coating basis weight.

[0014] Therefore, the present invention provides a system for coating continuous sheets, which enables improved uniform smoothness (especially for the application of high-gloss, transparent or similar coatings), wherein, due to their characteristics, they make it possible to easily see application defects, such as adhesive defects. Attached Figure Description

[0015] The following figures are included in the explanation of at least one embodiment of the present invention.

[0016] Figure 1 An embodiment of a system for coating a continuous sheet (1) according to the invention is shown, wherein the coating product is an adhesive (2) which is applied to the sheet (1) to cover a panel (3) having the sheet (1).

[0017] Figure 2 Another embodiment of a system for coating a continuous sheet (1) according to the invention is shown, wherein the coating product is an adhesive (2) applied to the sheet (1) for attaching the sheet (1) to another continuous sheet.

[0018] Figure 3 The application roller (10), smoothing roller (20), and corresponding application pressure element (11) and smoothing pressure element (21) are shown in detail, as well as for... Figure 1 and Figure 2 Other components of the system in the embodiments.

[0019] Figure 4a , 4b And 4c shows the use of Figures 1 to 3 The embodiments of the system are examples of consecutive steps in the operation of the system. Detailed Implementation

[0020] This invention relates to a system for applying a coating (such as an aesthetic coating) to component parts (such as panels or shapes) of furniture, and utilizes the system of the invention to achieve the features necessary to meet the requirements for applying a high-gloss, transparent or similar coating.

[0021] The application of adhesive (2) as described below is for coating products, for example, hot melt adhesives such as PUR, especially clear adhesives. Clear adhesives are advantageous for bonding clear sheets, thereby achieving proper visibility of the bottom of the coating.

[0022] The system includes an application head (40) having an application roller (10) and a dispensing roller (50). The dispensing roller (50) cooperates with the application roller (10) to dispense a certain amount of adhesive (2) onto the application roller (10) by means of the rotation and relative movement of the application roller (10) and the dispensing roller (50). An application pressure element (11) presses the sheet (1) against the application roller (10) so that the adhesive (2) is applied onto the sheet (1).

[0023] Once the adhesive (2) is applied to the sheet (1), the resulting coating is smoothed by means of a smoothing roller (20) arranged in the forward direction of the sheet (1) after the application roller (10). The smoothing pressure element (21) presses the sheet (1) against the smoothing roller (20) to smooth the adhesive coating applied by the application roller (10).

[0024] The continuous sheet (1) is supplied from the feed reel (4) by means of the guide roller (9), passing between the application roller (10) and the application pressure element (11) and between the smoothing roller (20) and the smoothing pressure element (21).

[0025] The proposed embodiment of the application head (40) is not limiting, as the dispensing roller (50) and the application roller (10) can also rotate in the same direction, and similarly, the contribution of the adhesive (2) to the application roller (10) can also be achieved by other means, such as by means of a passage-limiting element (e.g., in the form of a blade or scraper), or by means of an edge melter. Figure 3 As shown, according to the invention, the smoothing roller (20) is also designed to be fastened to the application head (40) together with the application roller (10) and (if appropriate) the dispensing roller (50).

[0026] Similarly, the relationship between the application roller (10) and the sheet (1) can allow the application roller (10) to rotate in the forward direction of the sheet (1), as shown, or in the opposite direction (without changing the actual function of the system).

[0027] Similarly, the smoothing roller (20) can rotate in the opposite direction to the advance of the sheet, as shown, or in the same direction. The rotation of the smoothing roller (20) makes it possible to prevent local wear of the roller and facilitates the removal of excess coated product caused by the smoothing process, which can be collected by means of elements that limit the passage of the coated product, such as blades (22).

[0028] exist Figure 1 In an embodiment of the system proposed in the paper, after smoothing, the sheet (1) passes through two consecutive calendering assemblies comprising corresponding calendering rollers (7), (8). By means of calendering, the bonded sheet (1) is secured to the panel (3), thereby covering the panel (3) and thus facilitating a completely uniform joint. The first calendering (7) secures the sheet to the base portion, while the second calendering (8) makes the joint more uniform.

[0029] exist Figure 2In an embodiment of the system proposed in the paper, after smoothing, the sheet (1) passes through two consecutive calendering assemblies comprising corresponding calendering rolls (7), (8). Figure 1 Unlike the embodiments presented in the previous one, by means of calendering, the glued sheet (1) is fastened to another continuous sheet supplied from another supply spool (5), which also facilitates a completely uniform joint. In the same manner, the first calendering (7) allows the glued sheet to be fixed to the other sheet, while the second calendering (8) allows the joint to be made more uniform. The layered product produced by the two connected sheets is wound in a collection spool (6).

[0030] In the proposed embodiment, the pressure-applying element (11) and the smoothing pressure element (21) are in the form of rotating rollers, but this embodiment is not limiting. Different solutions may then be used as the pressure-applying element (11) or the smoothing pressure element (21), such as slide rails, air cushions, etc. Advantageously, the rotating rollers allow for a reduction in friction and localized wear between the sheet and the pressure element.

[0031] According to the present invention, the pressure elements (11) and (21) are interchangeable, can be made of different materials, and have dimensions suitable for different applications. In particular, it is possible for the pressure elements (11) and (21) to have different lengths corresponding to different widths of the sheet.

[0032] In a preferred embodiment of the invention, the application roller (10), dispensing roller (50), and smoothing roller (20) are made of metal, which provides greater durability and less maintenance compared to rollers with a rubber coating. More preferably, the metal rollers are heated to facilitate the application and smoothing of the coated product, especially in the case of hot melt adhesives.

[0033] To move or smooth pressure elements, actuators, such as linear actuators, can be used. Figure 3 An application movement actuator (31) for moving the pressure application element (11) and a smooth movement actuator (32) for moving the smooth pressure element (21) are shown.

[0034] For example, by means of a pneumatic actuator, the corresponding pressure elements (11), (21) can be moved from an initial position to a final position, in which the corresponding pressure elements (11), (21) do not apply pressure to the sheet (1) against the application roller (10) or smoothing roller (20), and in the final position, the corresponding pressure elements (11), (21) apply some pressure to the sheet (1) against the rollers (10), (20). For example, by means of a worm gear actuator, the pressure elements (11), (21) can be moved to different positions in an adjustable and continuous manner, wherein the pressure elements (11), (21) apply different pressures against the rollers (10), (20).

[0035] Figure 3 A motion controller (30) is proposed, which acts on the applying motion actuator (31) and the smoothing motion actuator (32) to control the movement or adjustment of the applying pressure element (11) and the smoothing pressure element (21).

[0036] In an exemplary embodiment, the motion controller (30) is configured such that after the applying pressure element (11) presses the sheet (1) against the applying roller (10), the smoothing pressure element (21) begins to press the sheet (1) against the smoothing roller (20). Figure 4a , 4b Figures 4c and 4c show the sequence of movement of the pressure elements (11) and (21) controlled in this manner. In this way, it is possible to provide a smooth transition for system startup.

[0037] In particular, following the exemplary embodiments described in the preceding paragraphs, the movement controller (30) may be configured such that when the sheet (1) reaches a constant tension and / or forward speed, the smoothing pressure element (21) begins to press the sheet (1) against the smoothing roller (20). In this way, it is possible to prevent the formation of wrinkles or tension that could cause the sheet (1) to bend.

[0038] In another exemplary embodiment, the movement controller (30) is configured to move the smoothing pressure element (21) while keeping the applying pressure element (11) fixed. In this way, proper control of the uniformity of the applied coating is facilitated, and the movement of the smoothing pressure element can be changed exclusively to change the pressure applied by the smoothing roller (20) to the sheet (1).

Claims

1. A system for coating a continuous sheet (1), comprising: An application roller (10) is used to apply a coating onto the sheet (1) when the sheet (1) is pressed against the application roller (10) by an application pressure element (11). A smoothing roller (20) is used to smooth the coating applied to the sheet (1) by contact between the smoothing roller (20) and the coating when the sheet (1) is pressed against the smoothing roller (20) by a smoothing pressure element (21). The pressure-applying element (11) and the smoothing pressure element (21) can move independently to press the sheet (1); in, The system includes a movement controller (30) for controlling the movement of the pressure-applying element (11) and / or the smoothing pressure element (21); The movement controller (30) is configured such that after the applying pressure element (11) presses the sheet (1) against the applying roller (10), the smoothing pressure element (21) begins to press the sheet (1) against the smoothing roller (20).

2. The system for coating continuous sheets according to claim 1, wherein, The pressure-applying element (11) and / or the smoothing pressure element (21) are adjustable in their movement.

3. The system for coating continuous sheets according to claim 1, characterized in that, The movement controller (30) is configured such that when the sheet (1) reaches a constant tension and / or forward speed, the smoothing pressure element (21) begins to press the sheet (1) against the smoothing roller (20).

4. The system for coating continuous sheets according to any one of claims 1 to 3, wherein, The movement controller (30) is configured to move the smoothing pressure element (21) while keeping the pressure-applying element (11) fixed.

5. The system for coating continuous sheets according to any one of claims 1 to 4, characterized in that, The system for coating continuous sheets includes an application head (40), to which the application roller (10) and the smoothing roller (20) are fastened.

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