WO2008031825A1

WO2008031825A1 - An apparatus for and method of coating

Info

Publication number: WO2008031825A1
Application number: PCT/EP2007/059540
Authority: WO
Inventors: Jan Eddy De Rick; Bruno Paul Louis Vermeulen
Original assignee: Spanolux N.V.- Div. Balterio
Priority date: 2006-09-11
Filing date: 2007-09-11
Publication date: 2008-03-20
Also published as: CN101529031B; CN101529031A; PT1898024E; ES2401153T3; EP1898024A1; PL1898024T3; EP1898024B1; UA99441C2

Abstract

An apparatus for coating an edge portion (3) of a panel (4} comprises a support (1) which supports a coating (2) to be coated on the edge portion (3) and a support drive and guide system (5) for guiding the support (1) along the edge portion (3). The apparatus is provided with a biased press member (6) for pressing the support (1) and the coating (2) on the support (1) onto the edge portion (3} under all operating conditions.

Description

An apparatus for and method of coating

The present invention relates to an apparatus for coating an edge portion of a panel, comprising a support which supports a coating to be coated on the edge portion and a support drive and guide system for guiding the support along the edge portion.

Such an apparatus is known in the art and may be applied for coating an edge portion of a panel such as a laminate floor panel. This type of panels may be made on a wood basis and have a decoration layer, for example. The panels may have an edge portion in the form of a lowered part with respect to the upper surface of the panel so as to achieve a V-groove between two adjacent panels. It is desired to coat the edge portion of a panel in order to minimize the risk of penetration of water or the like into the panel material at the edge portion. However, the apparatus known in the art appear not to coat the edge portion entirely or the apparatus require very small tolerances to achieve a coating covering the edge portion entirely. Examples of known apparatus for coating panels are transfer press apparatus, vacuum systems, rolling machines and spray apparatus.

The present invention aims to provide an improved apparatus which eliminates the above-mentioned disadvantages.

For this purpose the apparatus is provided with a biased press member for pressing the support and the coating onto the edge portion under all operating conditions.

This appears to be advantageous, because the apparatus provides the opportunity to press the coating on the entire edge portion, independent from any small deviations between the positions of the support and the edge portion, which deviations might lead to leaving parts of the edge portion uncoated, such as in case of apparatus known in the art. In respect of known apparatus having a press means at a fixed location in the apparatus during coating, for example, the press means appears to wear soon and the coating may have a bad quality since due to tolerances in apparatus and/or panels the distance between the panel and press means may vary in practice. In the case of known rolling machines the roller is pressed away when the panel is moved through the machine, which leads to inappropriate contact between the roller and the edge portion. In the apparatus according to the invention, because of the pressure on the panel under all conditions, the level of the pressure may be relatively low, hence reducing the risk of wear of the apparatus. The coating may be a foil, paint, lacquer, or the like.

In a preferred embodiment the support is flexible. This has the advantage that the support may be deformed when the support and the coating are pressed onto the edge portion such that in case of a non-flat edge portion the coating is pressed on the entire surface thereof. In practice, the edge portion may have an irregular surface for improving the natural appearance of a panel.

In a practical embodiment the support comprises a belt, preferably an endless belt. The advantage of a belt is that it provides the opportunity to locate the biased press member with respect to the belt in a flexible way. The location along the belt may be relevant in respect of centrifugal forces; if the belt is guided by a roller the belt provides the opportunity to be in engagement with the biased press member at a location at a distance from the roller. This is for example impossible in case of known rolling systems. The apparatus may comprise a coating supplier for providing the coating onto the support. In a practical embodiment the coating supplier comprises a rotatable roller which is in engagement with the support and transfers the coating from a supply onto the support, which roller may have an embossed outer surface so as to provide the coating onto the support in a predetermined pattern. Alternatively, the coating supplier may comprise spray nozzles for spraying a liquid coating onto the support.

The advantage of applying a coating other than a foil is that no changes of foil supply rollers are necessary, such as in case of a transfer press apparatus, for example. In combination with an endless belt the apparatus may function continuously. Furthermore, a foil as a coating generally requires heating for appropriate adherence to the panel. This requires heating means and may introduce sensitivity to wear of the apparatus. An apparatus without heating means may improve the durability of the support.

The coating on the edge portion may be a decoration layer or a protective layer, for example. For enabling to apply a decoration layer, the coating supplier may be adapted such that the coating on the support has a predetermined pattern, such as a colour variation. Under operating conditions the pattern will be transferred to the edge portion. It is noted that different coatings or layers can be applied by the apparatus according to the invention.

The apparatus may be provided with a frame, and the biased press member may comprise a press element which is resiliently connected to the frame and in engagement with the belt at a side thereof which is opposite to a side which supports the coating. The resiliency may be achieved by a mechanical or pneumatic spring element, or the like. This keeps the belt and coating thereon under pressure under all operating conditions.

The press element may be at least a rotatable roller. As the roller may be rotated simultaneously with the belt the friction between the roller and the belt is minimized.

It is advantageous when the biased press member is provided with a press adjustment device for adjusting the pressing force on the support, because in that case the pressing force can be adjusted in relation to parameters defining the quality of the coating on the edge portion, such as the edge portion surface and the type of coating.

When the support is a belt which is guided by at least a roller and the coating supplier comprises a spray member for spraying a liquid coating onto the belt, the spray member is preferably located such that the liquid coating arrives on the belt at a distance from the roller so as to minimize the risk of flinging away of the coating due to centrifugal forces at the roller. Furthermore, since the coating is transferred to the support before coating it on the edge portion, it appears that problems related to often starting and stopping the spray member, such as in case of known spraying systems for coating a panel, are minimized.

The apparatus according to the invention has also the advantage that it has a high tolerance in respect of viscosity of the coating when compared with a known vacuum system, for example. The apparatus is not sensitive to air or dust.

Furthermore, a colour change can be performed rather simply.

The invention also relates to a method of coating an edge portion of a panel, wherein a coating is provided onto the edge portion and pressed thereon by a press member which is moved along the edge portion at the same time, wherein the press member is pressed in the direction of the edge portion under all operating conditions.

Preferably, at least a part of the surface of the panel adjacent to the edge portion is provided with an anti- adhesive before coating the edge portion, and any coating which is left on the anti-adhesive on the adjacent surface after coating, is removed together with the anti-adhesive, for example by brushing, because this results in a coating entirely covering the edge portion and only covering the edge portion.

The invention also relates to a method of coating a portion of a panel, wherein a coating is provided onto said portion, wherein at least a part of the surface of the panel adjacent to said portion is provided with an anti-adhesive before coating said portion, and wherein any coating which is left on the anti-adhesive on the adjacent surface after coating, is removed together with the anti-adhesive, preferably by brushing. This method may be independent from the method of coating or the surface of the portion. The portion may be a regularly or irregularly shaped lower edge portion of the panel which forms a V-groove when two panels are located adjacent to each other. The invention will hereafter be elucidated with reference to the very schematic drawings showing embodiments of the invention by way of example.

Fig. 1 is a schematic side view of the apparatus according to the invention, illustrating the method of coating of an edge portion according to the invention.

Fig. 2 is cross-sectional view taken along the line II-II in Fig. 1 on a larger scale.

Fig. 3 is a side view of a panel, illustrating a step of the method of coating according to the invention.

Fig. 4 is a top view of the panel of Fig. 3 on a smaller scale.

Figs. 5-7 are illustrative views of a manufacturing step in case of applying anti-adhesive before coating (Fig. 6 is a perspective view of a panel, and Figs. 5 and 7 are cross- sectional views of the panel of Fig. 6) .

Figs. 8-10 are similar views as Figs. 5-7, illustrating the application of a decoration layer on the edge portion . Figs. 11-13 are illustrative perspective views of panels of which the edge portions are coated by an apparatus known in the art.

Figs. 14 and 15 are illustrative cross-sectional views of a panel, illustrating a manufacturing step in case of applying a protective layer on the edge portion.

Figs. 16 and 17 are illustrative cross-sectional views of a panel, illustrating a manufacturing step in case of applying a scratch resistant layer on the edge portion.

Figs. 18 and 19 are illustrative views of finished panels after the manufacturing steps as illustrated in Figs. 5-10 and 14-17.

Fig. 20 is a view similar to Fig. 1, but illustrating an alternative method of providing a coating onto the support, and showing an apparatus having an alternative support guide system. Fig. 21 is an illustrative view of sequential coating steps and perspective views of the panel on enlarged scale, showing the results of the steps.

Fig. 1 shows a side view of an embodiment of an apparatus for coating an edge portion 3 of a panel 4 according to the invention, under operating conditions, and Fig. 2 shows a cross-sectional view taken along the line II-II in Fig. 1. With reference to Figs. 1 and 2 the apparatus comprises a support in the form of an endless belt 1, which supports a coating 2 to be coated on the edge portion 3 of the panel 4.

In the embodiment the belt 1 is guided by two rollers 5 and a press element in the form of a roller 7, which form a support drive and guide system for guiding the belt 1 along the edge portion 3. One of the rollers 5 may be driven such that the belt 1 is rotated in direction a as shown in Fig. 1.

Preferably, the speed of the belt 1 and the speed of the panel 4 are similar at the roller 7 in order to achieve a good coating result. The edge portion 3 of the panel 4 is a bevelled edge along sides of the panel 4. The panels 4 can be attached to each other by coupling means to form a floor covering; the coupling means may comprise a tongue (see Fig. 3) and a groove. Due to the bevelled edges a V-groove will be present between two adjacent panels 4.

The belt 1 may have different shapes, see the cross- sections thereof in Figs. 2 and 5. The belt may be made of plastic, metal, rubber or a composition of these materials.

The apparatus is provided with a biased press member 6 for pressing the belt 1 and the coating 2 on the belt 1 onto the edge portion 3 under all operating conditions. In this embodiment the belt 1 is a flexible element, hence deformable, which has the advantage that the coating 2 will also be pressed onto the entire edge portion 3 if a contact surface thereof does not entirely fit to a contact surface of the belt 1 in an non-deformed condition of the belt 1. For example, the contact surface of the belt 1 may be flat, whereas the contact surface of the edge portion may be embossed, or both contact surfaces may be not entirely parallel to each other. The biased press member 6 comprises a press element in the form of a rotatable roller 7 which is resiliently connected to a frame (not shown) of the apparatus. The roller 7, which in this case also guides the belt 1, is in engagement with the belt 1 at a side thereof which is opposite to a side which supports the coating 2. This is illustrated in Fig. 2. Several alternative press elements are conceivable, for example more than one roller 7, see Fig. 20, for example. Having more than one roller 7 may improve the guidance of the belt 1 further. The roller 7 is connected to the frame by a spring, which alternatively may be replaced by a pneumatic member. Preferably, the biased press member 6 is provided with a press adjustment device (not shown) for adjusting the pressing force on the belt 1. Normally, the roller 7 is movable in a direction perpendicularly to the surface of the belt 1 at the roller 7 as indicated by arrow A in Fig. 1.

According to the invention it is relevant that the biased press member 6 presses onto the belt 1 and the coating

2 under all operating conditions so as to avoid a situation as illustrated in Fig. 11. In the case of Fig. 11 the bevelled edge portion 3 is not entirely covered since the edge portion

3 to be coated has a lower part 15 with respect to the remaining part which remains uncoated in case of lacking a biased press member 6. This leads to an undesired appearance of the panels 4 as shown in Fig. 13.

The apparatus also comprises a coating supplier (not shown) for providing the coating 2 onto the belt 1. Fig. 1 shows that the coating 2 on the belt 1 is transferred to the edge portion 3 and pressed thereon as explained hereinbefore. The coating supplier is, for example, a rotatable roller which is in engagement with the belt 1 and transfers the coating 2 in the form of a paint from a supply onto the belt 1. The roller may have an embossed outer surface so as to provide the paint onto the belt in a predetermined pattern in order to transfer the pattern to the edge portion 3. The embossed surface may be obtained by laser treating a metal surface of the roller. Alternatively, the coating 2 is a foil or the like. It is noted that several coating steps may be repeated.

Fig. 20 shows an alternative coating supplier in the form of a spray member 17, which sprays a paint or the like onto the belt 1. The location of the spray member 17 at a distance from the guide roller 5 is advantageous because the centrifugal forces at that location are small or even zero. This means that the risk of removing the coating 2 after it has been sprayed onto the belt is minimized. Figs. 3-10 and 14-17 illustrate manufacturing steps of an example of the method of coating the edge portion 3 of a panel 4 according to the invention. Figs. 3 and 4 show that a part of the surface of the panel 4 adjacent to the edge portion 3, in this case beyond an edge 10 as seen from the edge portion 3 to the remaining portion of an upper surface 9 of the panel 4, is provided with an anti-adhesive 11. The width of the anti-adhesive 11 along the edge 10 is preferably smaller than 4 mm, but may be larger. The anti-adhesive can also be provided onto the upper surface 9 before machining the panel 4 such that the lower edge portion 3 is made, because in this case the edge portion 3 is automatically made free of anti-adhesive 11. The anti-adhesive prevents the coating 2 from being fixed to the panel 4 outside the edge portion 3, in this case the upper surface 9. Fig. 12 shows the result of applying a coating 2 on the edge portion 3 without using anti- adhesive 11. This means that a part 14 of the coating 2 remains on the upper surface 9 of the panel 4, which may lead to an undesired appearance as illustrated in Fig. 13.

Figs. 5 - 7 illustrate the pressing of the coating onto the edge portion 3 as explained hereinbefore and the result thereof. Figs. 6 and 7 show in a perspective and cross- sectional view, respectively, that the coating 2 is also pressed on the anti-adhesive 11 outside the edge portion 3. As a consequence, the edge portion 3 is entirely covered by the coating 2, but the coating 2 is not fixed to the upper surface 9. Figs. 8-10 show an additional coating step, which can be performed with a similar apparatus as above. Possible sequential coating steps comprise the application of one or more lacquer layers, decoration layer and protective layers, but alternatives are conceivable. If necessary, between the coating steps the coating 2 present on the edge portion 3 can be dried first (in the case of paint, for example) , for example by hot air, UV light, or the like. It is also possible to dry the coating 2 only partly so as to achieve a better fixing between the layers of coating 2. Figs. 8-10 illustrate a coating step wherein a decoration pattern is applied by providing a pattern of ink 13 on the belt 1, for example by an embossed roller as explained hereinbefore or spray nozzles which spray ink on the belt in an irregular way. Variations with different colours are also possible. The pattern on the edge portion 3 can be related to that on the upper surface 9, see Fig. 9.

The decoration layer can be covered by one or more protective layers 16. This is illustrated in Figs. 14 and 15. The protective layer may be a transparent lacquer containing wear resistant material, for example corundum particles.

A next layer which may be applied can be a scratch resistant layer 17, see Figs. 16 and 17.

Finally, when all desired layers are coated on the edge portion 3 any coating 2, 13, 16, 17 which is left on the anti-adhesive on the upper surface 9 after coating, is removed by removing it together with the anti-adhesive 11. This can be done relatively simply by brushing, or the like. As a result the coating 2 and the layers 13, 16, 17 cover the edge portion entirely and only, such as illustrated in Figs. 18 and 19. It is noted that the method of providing anti-adhesive may be applied in alternative methods, separate from pressing the coating onto the panel.

Fig. 21 shows a side view of an alternative apparatus, illustrating sequential manufacturing steps of an example of a method of coating according to the invention. The perspective views of the panel 4 in the Fig. show the result of the separate manufacturing steps. The panel 4 moves from the right to the left in Fig. 21. In the first step a paint is sprayed onto the belt 1 by spray member 17. In the next step the paint is dried by a dryer 18. Then, a decoration pattern is printed onto the edge portion 3 by transferring a pattern of ink 13 on the belt 1 through a coating supplier in the form of a roller 19. The associated enlarged view shows that the type of pattern on the edge portion 3 is similar to that on the upper surface 9 of the panel 4. Subsequently, the paint pattern is dried by dryer 18. Of course, additional layers may be provided on the edge portion 3.

The panel 4 may be a laminate comprising different layers, preferably based on wood, for example made of MDF, HDF, fibreboard, plywood or the like. The panel 4 may also be made of plastic or a mixture of wood and plastic, such as WPC panels. The decoration side of the panel may be embossed and the panels may be suitable for floor, wall or ceiling covering.

From the foregoing, it will be clear that the invention provides an apparatus for and a method of coating an edge portion of a panel only and entirely at the same time.

The invention is not limited to the examples shown in the drawings and described hereinbefore, which may be varied in different manners within the scope of the claims and their technical equivalents. For example, the support and press element may be an integral part formed by a roller on which a coating is supplied and which coating is directly pressed onto the edge portion by the roller. The roller may be a rigid one and the flexibility of the material at the edge portion of the panel may be used to cover the entire edge portion with a coating. Furthermore, the apparatus is suitable for other coatings, such as stain, oil-based coating, and the like.

Claims

1. An apparatus for coating an edge portion (3) of a panel (4), comprising a support (1) which supports a coating (2) to be coated on the edge portion {3) and a support drive and guide system (5) for guiding the support (1) along the edge portion (3) , characterized in that the apparatus is provided with a biased press member (6) for pressing the support (1) and the coating (2) on the support (1) onto the edge portion (3) under all operating conditions.

2. An apparatus according to claim 1, wherein the support (1) is flexible.

3. An apparatus according to claim 2, wherein the support comprises a (n) (endless) belt (1).

4. An apparatus according to one of the preceding claims, wherein the apparatus comprises a coating supplier for providing the coating (2) onto the support (1) .

5. An apparatus according to claim 4, wherein the coating supplier is adapted such that the coating (2) on the support (1) has a predetermined pattern, such as a colour variation.

6. An apparatus according to claim 4 or 5, wherein the coating supplier comprises a rotatable roller which is in engagement with the support (1) and transfers the coating (2) from a supply onto the support (1) , which roller may have an embossed outer surface so as to provide the coating (2) onto the support (1) in a predetermined pattern.

7. An apparatus according to claim 3, wherein the apparatus is provided with a frame, and the biased press member (6} comprises a press element (7) which is resiliently connected to the frame and in engagement with the belt (1) at a side thereof which is opposite to a side which supports the coating (2) .

8. An apparatus according to claim I₁ wherein the press element (7) is at least a rotatable roller.

9. An apparatus according to one of the preceding claims, wherein the biased press member (6) is provided with a press adjustment device for adjusting the pressing force on the support (1) .

10. An apparatus according to claim 3 and 4, wherein the belt (1) is guided by at least a roller (5) and the coating supplier comprises a spray member (17) for spraying a liquid coating (2) onto the belt, wherein the spray member (17) is located such that under operating conditions the liquid coating (2) arrives on the belt (1) at a distance from the roller (5) .

11. Method of coating an edge portion (3) of a panel

(4), wherein a coating (2) is provided onto the edge portion (3) and pressed thereon by a press member (7) which is moved along the edge portion (3) at the same time, wherein the press member (7) is pressed in the direction of the edge portion (3) under all operating conditions.

12. Method according to claim 11, wherein at least a part of the surface (9) of the panel (4) adjacent to the edge portion (3) is provided with an anti-adhesive before coating the edge portion (3), and wherein any coating (2) which is left on the anti-adhesive (11) on the adjacent surface (9) after coating, is removed together with the anti-adhesive, preferably by brushing.

13. Method of coating a portion (3) of a panel (4), wherein a coating (2) is provided onto said portion (3) , wherein at least a part of the surface (9) of the panel (4) adjacent to said portion (3) is provided with an anti-adhesive before coating said portion (3) , and wherein any coating (2) which is left on the anti-adhesive (11) on the adjacent surface (9) after coating, is removed together with the anti- adhesive (11), preferably by brushing.