Abstract
A method for the adhesive bonding of substrates by applying a layer of adhesive (1) on a first substrate and/or on a second substrate; and positioning the first substrate on the second substrate, with the applied layer of adhesive (1) arranged therebetween. Before positioning the first substrate on the second substrate, the method proceeds by applying radiation-based curing means (13) to the layer of adhesive (1) to selectively and partially cure the layer of adhesive (1).
Claims
1. A method for adhesive bonding of substrates, comprising: applying an adhesive layer (1) on a first substrate and/or on a second substrate; and positioning the first substrate on the second substrate, with interposition of the applied adhesive layer (1); wherein before positioning the first substrate on the second substrate, applying radiation curing means (13) on the adhesive layer (1) in order to partially cure said adhesive layer (1) in a selected manner.
2. The method for adhesive bonding of substrates according to claim 1, wherein to position the first substrate on the second substrate, the method further comprises postforming, by means of postforming means (8; 12), at least one strip (2′, 2b, 2c, 2d) of the first substrate on at least one contour (14) of the second substrate.
3. The method for adhesive bonding of substrates according to claim 2, wherein the curing means (13) are applied in correspondence with the at least one strip (2′, 2b, 2c, 2d) of the first substrate prior to and/or during the postforming thereof on the at least one contour of the second substrate.
4. The method for adhesive bonding of substrates according to claim 2, wherein the postforming step is carried out in several steps, by means of the postforming means (8; 12), different strips (2′, 2b, 2c, 2d) of the first substrate on different contours (14) of the second substrate, and further comprising performing at least one additional application of the curing means (13) between two steps of the postforming.
5. The method for adhesive bonding of substrates according to claim 1, further comprising, applying the curing means (13) on a first strip (2a) of the first substrate that will not be postformed.
6. The method for adhesive bonding of substrates according to claim 1, wherein the application of the curing means (13) comprises applying a radiation selected from the group consisting of electromagnetic radiation, in particular, UV or IR, and corpuscular radiation, in particular, with electrons, to the adhesive layer (1).
7. The method for adhesive bonding of substrates according to claim 1, further comprising, performing a smoothing of the adhesive layer (1) immediately after the application thereof on the first substrate and/or on the second substrate.
8. The method for adhesive bonding of substrates according to claim 1, wherein the first substrate is a coating material (2) and the second substrate is a coating support (3) whereon the coating material (2) is positioned.
9. The method for adhesive bonding of substrates according to claim 1, further comprising using an adhesive configured with a curing mechanism additional to that of curing by radiation.
10. The method for adhesive bonding of substrates according to claim 9, wherein the additional curing mechanism is due to a reaction with the humidity of the air, wherein the adhesive is made of reactive PUR.
11. A system for adhesive bonding of substrates, wherein a first substrate is a coating material (2) and a second substrate is a coating support (3) whereon the coating material (2) is positioned, wherein the system comprises application means for applying an adhesive layer (1) on the coating material (2) and/or on the coating support (3), and positioning means (8; 9, 12) for positioning the coating material (2) on the coating support (3), radiation curing means (13) for partially curing the adhesive layer (1) arranged between the application means for applying the adhesive layer (1) and the positioning means (8; 9, 12) in a selected manner.
12. The system for adhesive bonding of substrates according to claim 11, wherein the positioning means (8; 9, 12) comprise postforming means (8; 12) for postforming at least one strip (2′, 2b, 2c, 2d) of the coating material (2) on at least one contour (14) of the coating support (3).
13. The system for adhesive bonding of substrates according to claim 11, configured to perform a method comprising: applying the adhesive layer (1) on the first substrate and/or on the second substrate; and positioning the first substrate on the second substrate, with interposition of the applied adhesive layer (1); wherein before positioning the first substrate on the second substrate, applying radiation curing means (13) on the adhesive layer (1) in order to partially cure said adhesive layer (1) in a selected manner.
14. A product for adhesive bonding of substrates obtained according to the method described in claim 1.
15. The method for adhesive bonding of substrates according to claim 9, wherein the adhesive is an adhesive with a dual curing mechanism.
Description
DESCRIPTION OF THE FIGURES
[0069] As part of the explanation of at least one embodiment of the invention, the following figures have been included.
[0070] FIG. 1 shows a schematic view of the structure in the form of crests and valleys of an adhesive/glue layer applied by means of an applicator roller on a coating sheet or on a panel.
[0071] FIG. 2a shows a system for adhesive bonding of substrates with postforming of the assembly formed by the panel and coating sheet, wherein the adhesive is applied to the continuous coating sheet by means of an applicator roller, with a subsequent phase of smoothing the adhesive layer on the coating sheet.
[0072] FIG. 2b shows a system for adhesive bonding of substrates like the one in FIG. 2a, wherein there is no phase of smoothing the adhesive layer on the coating sheet after the application thereof.
[0073] FIG. 3a shows a system for adhesive bonding of substrates with postforming of the assembly formed by the panel and coating sheet, wherein the adhesive is applied to the coating sheet by means of a lip, with a subsequent phase of smoothing the adhesive layer on the coating sheet.
[0074] FIG. 3b shows a system for adhesive bonding of substrates like the one in FIG. 3a, wherein there is no phase of smoothing the adhesive layer on the coating sheet after the application thereof.
[0075] FIG. 4 shows a system for adhesive bonding of substrates with postforming of the assembly formed by the panel and coating sheet, wherein the adhesive is applied to the coating sheet by means of spray nozzles.
[0076] FIG. 5 shows a system for adhesive bonding of substrates like the one in FIG. 3b, wherein there are curing means inserted between the different postforming means.
[0077] FIG. 6 shows a simplified view of a cross section of the coating sheet.
[0078] FIG. 7 shows a simplified view of a cross section of the panel whereon the coating sheet is positioned.
[0079] FIG. 8 shows a simplified view of a cross section of the coating sheet with an adhesive/glue layer applied without smoothing.
[0080] FIG. 9 shows a simplified view of a cross section of the coating sheet with an adhesive/glue layer that is applied and smoothed.
[0081] FIG. 10a shows a simplified view of the use of curing means for curing the adhesive on two end strips of the adhesive layer applied on the coating sheet.
[0082] FIG. 10b shows a simplified view of the coating sheet of FIG. 10a, with the two end strips in an advanced state of curing, wherein the coating sheet is positioned on the panel, with interposition of the adhesive layer, before the postforming of the assembly formed by the panel and coating sheet.
[0083] FIG. 10c shows a simplified view of the assembly of panel and coating sheet of FIG. 10b, after the postforming.
[0084] FIG. 11a shows a simplified view of the use of curing means for curing the adhesive on the entirety of the adhesive layer applied on the coating sheet.
[0085] FIG. 11b shows a simplified view of the coating sheet of FIG. 11a, with all of the adhesive layer thereof in an advanced state of curing, wherein the coating sheet is positioned on the panel, with interposition of the adhesive layer, before the postforming of the assembly formed by the panel and coating sheet.
[0086] FIG. 11c shows a simplified view of the assembly of panel and coating sheet of FIG. 11b, after the postforming.
[0087] FIG. 12 shows a simplified view, according to cross section HH of FIG. 5, wherein a first application of curing means for curing the adhesive is seen on a first strip of the adhesive layer deposited on the coating sheet, wherein the first strip of the adhesive layer corresponds to a first strip of the coating sheet that will not be postformed after the positioning thereof on the panel.
[0088] FIG. 13 shows a simplified view, according to cross section II of FIG. 5, wherein a second application of curing means for curing the adhesive is seen on two second strips of the adhesive layer deposited on the coating sheet, wherein the two second strips of the adhesive layer correspond to two second strips of the coating sheet that will be postformed after the positioning of the coating sheet on the panel.
[0089] FIG. 14 shows a simplified view, according to cross section JJ of FIG. 5, wherein a third application of curing means for curing the adhesive is seen on a third strip of the adhesive layer deposited on the coating sheet, wherein the third strip of the adhesive layer corresponds to a third strip of the coating sheet that will be postformed after the postforming of the second strips of the coating sheet.
[0090] FIG. 15 shows a simplified view, according to cross section KK of FIG. 5, wherein a fourth application of curing means for curing the adhesive is seen on a fourth strip of the adhesive layer deposited on the coating sheet, wherein the fourth end strip of the adhesive layer corresponds to a fourth end strip of the coating sheet that will be postformed after the postforming of the third strip of the coating sheet.
[0091] FIG. 16 shows a simplified view, according to cross section LL of FIG. 5, wherein it shows the assembly formed by panel and coating sheet, after the postforming of the fourth end strip of the coating sheet.
[0092] FIG. 17 shows a system for adhesive bonding of substrates with postforming of the assembly formed by the panel and continuous coating sheet, wherein the adhesive is applied to the continuous coating sheet by means of a lip, as well as to the panel by means of an applicator roller with subsequent smoothing of the adhesive layer on the panel.
[0093] FIG. 18 shows a system for adhesive bonding of substrates without postforming of the assembly formed by the panel and continuous coating sheet, wherein the adhesive is applied to the panel by means of an applicator roller with subsequent smoothing of the adhesive layer on the panel.
[0094] FIG. 19 shows a system for adhesive bonding of substrates without postforming of the assembly formed by the panel and discontinuous coating sheet, wherein the adhesive is applied to the panel by means of an applicator roller with subsequent smoothing of the adhesive layer on the panel.
[0095] FIG. 20a shows a simplified view of a cross section of the panel with an adhesive/glue layer applied without smoothing.
[0096] FIG. 20b shows a simplified view of a cross section of the panel with an adhesive/glue layer that is applied and smoothed.
[0097] FIG. 20c shows a simplified view of a cross section of the panel with an adhesive/glue layer applied in an advanced state of curing.
[0098] FIG. 21a shows a simplified view of a cross section of the coating sheet with an adhesive/glue layer applied without smoothing.
[0099] FIG. 21b shows a simplified view of a cross section of the coating sheet with an adhesive/glue layer that is applied and smoothed.
[0100] FIG. 21c shows a simplified view of a cross section of the coating sheet with an adhesive/glue layer that is applied in an advanced state of curing.
[0101] FIG. 22 shows a simplified view of the assembly of panel and coating joined without postforming.
DETAILED DESCRIPTION OF THE INVENTION
[0102] The present invention relates, as mentioned earlier, to a method and to a system for adhesive bonding of substrates.
[0103] In order to prevent, among others, the aforementioned drawbacks regarding the structuring of the adhesive (1) (see FIG. 1), the system and the method of the invention envisage that the adhesive (1) can be applied with a low enough viscosity so that the application thereof does not cause defects or enable an efficient smoothing after the application or, if smoothing means are lacking, enabling an automatic levelling of the adhesive layer (1) before the curing process advances too far, producing an increase in the viscosity of the adhesive (1) which would prevent the subsequent smoothing or automatic levelling of the adhesive layer (1).
[0104] To this end, according to the invention, by means of radiation curing means (13) a semi-curing or partial curing of the applied adhesive (1) is performed, before the positioning of the substrates. The adhesive (1) used in the embodiments described below has a dual curing mechanism, the additional curing mechanism being due to a reaction with the moisture, such that, once the substrates have been positioned, the complete curing of the adhesive (1) takes place due to a reaction with the humidity of the air (which can cross through the positioned substrate or the base substrate to the interposed adhesive layer). An example of this type of adhesive is commercially available under the brand name “Dual Curing” by Henkel, which is a PUR-based adhesive which is reactive with moisture.
[0105] The use of this type of adhesive (1) or substrates described below is not limiting for the invention. Thus, for example, according to the invention it is also envisaged that a complete curing of the adhesive layer (1) can be performed after the positioning of the substrates also by radiation, in particular, by UV electromagnetic radiation, the latter if the positioned substrate is transparent or translucent to said radiation.
[0106] FIG. 2a and FIG. 3a show two embodiments, according to the present invention, of a system for manufacturing laminated panels with postforming wherein it has been envisaged that, after the application of the adhesive (1) by means of an applicator roller (4) and a dosing roller (5) (FIG. 2a) or by means of a lip (6) (FIG. 3a), there is a smoothing roller (7).
[0107] FIG. 2b and FIG. 3b show two embodiments, according to the present invention, of systems for manufacturing laminated panels with postforming which are similar respectively to those of FIG. 2a and FIG. 3a, but wherein said smoothing has not been envisaged after the application of the adhesive layer (1) on the coating sheet (2).
[0108] FIG. 4 shows an embodiment, according to the present invention, of a system for adhesive bonding of substrates with postforming similar to that of FIG. 2b, but wherein the application of the adhesive layer (1) is applied by means of a glue spray nozzle (15) instead of by means of an applicator roller (4).
[0109] In the mentioned figures, the advance direction of the coating sheet (2) and the panel (3) is indicated by arrows along the system for adhesive bonding of substrates with postforming, as well as the direction of rotation of the rollers.
[0110] Whether or not there is specifically a smoothing roller (7), in all the systems for adhesive bonding of substrates with postforming shown in the figures, there is a positioning roller (9) for the coating sheet (2) on the panel (3) to be postformed. This positioning roller (9) can also fulfil a certain smoothing function for the adhesive layer (1) located between the coating sheet (2) and the panel (3), by exerting a pressure on the coating sheet (2) (and therefore, on the adhesive layer (1)) against the panel (3).
[0111] Nevertheless, taking into account that the positioning roller (9) acts after a time has passed since the application of the adhesive layer (1) on the coating sheet (2), it is desirable for the smoothing or automatic levelling of the adhesive layer (1) to have started earlier, since the time it is applied on the coating sheet (2). For this reason, it is desirable to arrange the adhesive (1) with a very low viscosity at the time it is applied on the coating sheet (2). The same would happen if it is applied to the panel (3) or both.
[0112] In all the systems for adhesive bonding of substrates with postforming shown in the figures, there is also a guide roller (10), which ensures that the coating sheet (2) is maintained in the path thereof from the coil (11) to the panel (3).
[0113] In systems for adhesive bonding of substrates with postforming, after the positioning of the coating sheet (2) on the panel (3), it is necessary to perform postforming operations in order to couple and adapt, in those cross sections or strips where necessary, the coating sheet (2) to the geometry of the contours (14) of the panel (3). To do this, after the positioning of the coating sheet (2) on the panel (3), there are postforming means (12) (typically consisting of postforming rollers (8) and/or presses) which perform the adaptation of the coating sheet (2) to the specific geometry of each cross section, strip or contour (14) of the panel (3).
[0114] As already mentioned, it is important that, at the right times, the adhesive (1) which forms the adhesive layer (1) has the suitable viscosity and internal cohesion. This is especially important during the postforming operations since, as they are normally narrow cross sections or strips of the coating sheet (2) that have to coat narrow strips or contours (14) of the panel (3), the elastic force exerted by the coating sheet (2) to recover the extended geometry thereof (before the postforming) is very intense, therefore requiring the adhesive (1) to have a high adhering strength at the precise moment when the postforming operations are to be performed.
[0115] For this reason, the method for adhesive bonding of substrates object of the present invention foresees the application of curing means (13) for the adhesive layer (1) in those strips of the adhesive layer (1) located on corresponding strips of the coating sheet (2) that will be postformed in order to be adapted to corresponding strips, cross sections or contours (14) of the panel (3).
[0116] The curing means (13) may comprise means for emitting infrared radiation (IR, NIR), emission means for emitting ultraviolet (UV) radiation or another type of radiation. These curing means are configured to perform a partial curing of the adhesive in a selected manner, enabling the application of a selected radiation energy to the adhesive layer.
[0117] Thus, in FIG. 2a, FIG. 2b, FIG. 3a, FIG. 3b, FIG. 4 and FIG. 5, the application of curing means (13) for the adhesive layer (1) is seen at an instant immediately after the application of the adhesive layer (1) on the coating sheet (2) and at a time before the positioning and postforming of the coating sheet (2) on the panel (3). These curing means (13) can be applied on the entirety or on particular strips of the adhesive layer (1) located on particular strips of the coating sheet (2) that will be postformed on corresponding strips, cross sections or contours (14) of the panel (3). In this manner, the process of curing the adhesive layer (1) in said strips to be postformed is accelerated so that when the postforming operation has to be carried out, said strips of the adhesive layer (1) have the ideal properties of viscosity and internal cohesion which enable the coating sheet (2) to stay perfectly adhered to the panel (3) in said strips or contours (14) without the coating sheet (2) coming off the panel (3) and recovering the initial shape thereof.
[0118] Likewise, in FIG. 5, a variant of a system of the system for adhesive bonding of substrates with postforming is seen for the execution of an embodiment of the method for adhesive bonding of substrates wherein curing means (13) are applied inserted between successive applications of postforming means (12) on the coating sheet (2) and on the panel (3). In this manner, the curing of the adhesive layer (1) is accelerated instantaneously and at the right times in the corresponding strips that will be postformed in each postforming step, at each instant immediately before the postforming of the corresponding strips.
[0119] FIG. 6 shows a cross-sectional view of the coating sheet (2) before the application of the adhesive layer (1), i.e., a view corresponding to the cross section GG indicated, for example, in FIG. 2a and in FIG. 2b.
[0120] FIG. 7 shows a cross-sectional view of the panel (3) before the positioning of the coating sheet (2), i.e., a view corresponding to the cross section FF indicated, for example, in FIG. 2a and in FIG. 2b. A contour (14) of the panel (3) is shown to which the coating sheet (2) will have to be coupled subsequently by means of one or more postforming operations.
[0121] FIG. 8 shows a cross-sectional view of the coating sheet (2) with the adhesive layer (1) recently applied and without smoothing or automatic levelling, such that the structuring of the adhesive layer (1) forming crests and valleys or other defects can be seen. This view corresponds to the cross section AA indicated, for example, in FIG. 2a.
[0122] FIG. 9 shows a cross-sectional view of the coating sheet (2) with the adhesive layer (1) already smoothed or automatically levelled or applied without defects. This view corresponds to the cross section BB indicated, for example, in FIG. 2a, FIG. 2b, FIG. 3a, FIG. 3b, FIG. 4 and FIG. 5.
[0123] FIG. 10a shows a cross-sectional view of the coating sheet (2) and the adhesive layer (1), wherein the application of curing means (13) to two end strips (2′) of the adhesive layer (1) can be seen. This view corresponds to the cross section CC indicated, for example, in FIG. 2a, FIG. 2b, FIG. 3a, FIG. 3b and FIG. 4.
[0124] The portions or strips of the adhesive layer (1) subjected to the curing means (13) are shown in a dark colour in the figures, as opposed to the portions of the adhesive layer that have not been subjected to the curing means (13).
[0125] FIG. 10b shows the positioning of the coating sheet (2) of FIG. 10a on the panel (3). This view corresponds to the cross section DD indicated, for example, in FIG. 2a, FIG. 2b, FIG. 3a, FIG. 3b and FIG. 4. The panel (3) shows a contour (14) on the right with a geometry that is curved and more complicated than the other contour (14) on the left end, which has a simple, straight geometry.
[0126] FIG. 10c shows the coating sheet (2) of FIG. 10b, after the postforming of the end strips (2′) on the contours (14) of the panel (3). This view corresponds to the cross section EE indicated, for example, in FIG. 2a, FIG. 2b, FIG. 3a, FIG. 3b and FIG. 4.
[0127] FIG. 11a, FIG. 11b and FIG. 11c respectively show views and cross sections similar to those of FIG. 10a, FIG. 10b and FIG. 10c. Nevertheless, in the case of FIG. 11a, FIG. 11b and FIG. 11c, the curing means (13) have been applied on the entire adhesive layer (13) and not only on certain strips.
[0128] The invention also envisages applying the curing means (13) on the entire surface of the adhesive layer (1), but with a different intensity according to different strips of the adhesive layer (1). This enables different degrees of viscosity and internal cohesion to be achieved on different strips of the adhesive layer (1), depending on whether or not postforming operations need to be performed on said strips of the adhesive layer (1), or depending on the severity of said postforming operations, severity being understood as the intricate, closed or angular nature of the geometry of the contour (14) of the panel (3) to be coated. The more intricate, closed or angular this geometry is, the greater the tendency of the coating sheet (2) to recover the initial geometry thereof and, therefore, the more critical it will be for the adhesive layer (1) in said strips to have a greater adhering strength.
[0129] It is worth mentioning (as just introduced) that sometimes it may be interesting to apply curing means (13) to strips of the adhesive layer (1) corresponding to strips of the coating sheet (2) that will not be postformed. This is because sometimes the strips that will not undergo postforming are very narrow and, therefore, when contiguous strips of the coating sheet (2) are postformed, there is a risk of a relative displacement being produced between the coating sheet (2) and the panel (3), as well as in the narrow strips not subjected to postforming. For this reason, it is also of interest to apply curing means (13) to these strips that will not be postformed, in order to increase the firmness of the adhesion of the coating sheet (2) to the panel (3) in said strips, in order to prevent possible subsequent relative displacements between the coating sheet (2) and the panel (3).
[0130] As already mentioned when commenting on FIG. 5, the method for adhesive bonding of substrates object of the present invention foresees the application of curing means (13) at different times throughout the lamination process.
[0131] FIG. 12 shows a first application of curing means (13) on the adhesive layer (1) in correspondence with a first central strip (2a) of the coating sheet (2), which subsequently, as seen in FIG. 13, will be positioned on a diaphanous area of the panel (3) and will not undergo postforming. This view of FIG. 12 corresponds to the cross section HH shown in FIG. 5.
[0132] FIG. 13 corresponds to the cross section II shown in FIG. 5. FIG. 13 shows a second application of curing means (13) on the adhesive layer (1), in correspondence with second strips (2b) of the coating sheet (2) that will be postformed on respective contours (14) of the panel (3). A contour (14) whereon the coating sheet (2) will be postformed is located on the left end of the panel (3), and it has a straight geometry. The other contour (14) is located on the right (14) of the panel (3), and is the first of a succession of steps of a stepped geometry.
[0133] FIG. 14 shows the second strips (2b) of the coating sheet (2) of FIG. 13 already postformed on the panel (3). FIG. 14 shows a third application of the curing means (13) on the adhesive layer (1), in correspondence with a third strip (2c) of the coating sheet (2) that will be postformed on the respective contour (14) of the panel (3). This view of FIG. 14 corresponds to the cross section JJ shown in FIG. 5.
[0134] FIG. 15 shows the third strip (2c) of the coating sheet (2) of FIG. 14 already postformed on the panel (3). FIG. 15 shows a fourth application of the curing means (13) on the adhesive layer (1), in correspondence with a fourth strip (2d) of the coating sheet (2) that will be postformed on the respective contour (14) of the panel (3). This view of FIG. 15 corresponds to the cross section KK shown in FIG. 5.
[0135] FIG. 16 shows the coating sheet (2) of FIG. 5 completely postformed (in the corresponding strips (2b, 2c, 2d)) on the panel (3) of FIG. 5. This view of FIG. 16 corresponds to the cross section LL shown in FIG. 5.
[0136] FIG. 17 shows an additional embodiment, according to the present invention, of a system for manufacturing laminated panels with postforming similar to the embodiment shown in FIG. 5, wherein, unlike this one, it has been envisaged that an additional application of adhesive (1) also takes place by means of an applicator roller (4) and a dosing roller (5) on the panel (3) before the positioning of the coating sheet (2) on the panel (3). Between the positioning, by means of the positioning roller (9) and the application of adhesive (1) on the panel (3), a smoothing takes place by means of the smoothing roller (7) and a semi-curing by means of curing means (13), for example, by UV radiation.
[0137] FIG. 18 shows an additional embodiment, according to the present invention, of a system for manufacturing laminated panels, wherein, unlike the previous embodiments, the adhesive layer is applied only on the panel (3), not on the sheet (2). In the example of the embodiment shown, postforming is not performed.
[0138] FIG. 19 shows an additional embodiment, according to the present invention, of a system for manufacturing laminated panels, wherein, unlike the previous embodiments, the coating sheet (2) is supplied discontinuously, i.e., sheet by sheet, from a stack of coating sheets (2). In the example of the embodiment shown, postforming is not performed.
[0139] FIGS. 20a, 20b, 20c and 22 show a cross-sectional view of the panel (3) in the corresponding cross sections MM, NN, OO and SS of the embodiments shown in the previous Figures.
[0140] FIGS. 21a, 21b and 21c show a cross-sectional view of the sheet (2) in the corresponding cross sections PP, QQ and RR of the embodiments shown in the previous Figures.
