MXPA06010690A - Panel assembly and method for its production - Google Patents

Abstract

The panel assembly comprises a panel (2) and a gasket (1) adhered to the panel and extending along at least a portion of the periphery. For producing the panel assembly a curable composition is applied either directly or indirectly onto the panel and onto a mould surface (6) onto which the panel has been positioned. When being applied on the mould 5 surface, the curable composition has a dynamic viscosity which is lower than the dynamic viscosity of extrusion materials. In this way, a better surface quality can be achieved without having to exert a high pressure onto the curable composition. In contrast to the known RIM processes, the curable composition is not injected in a closed mould but is applied 10 onto an open mould surface by means of an applicator device (9) moving along at least said portion of the periphery of the panel (2). In this way, cheaper moulds can be used and in particular moulds made of a soft, resilient material (8).

Description

PANEL ASSEMBLY AND METHOD FOR ITS PRODUCTION DESCRIPTIVE MEMORY The present invention relates to a method for producing a panel assembly, in particular a panel assembly for use in an opening of the vehicle, comprising a panel and a gasket, which adheres to the panel, which extends along the length of the panel. at least a portion of the periphery thereof and having a surface, at least a portion of which is molded against a solid surface, the method comprises the steps of: - providing a mold with at least one mold surface; - place the panel and the surface of the mold against each other; - applying a curable composition to produce said joint directly or indirectly on the surface of the mold and directly or indirectly on said panel, the curable composition has a dynamic viscosity, measured at a shear rate of 1 / s, less than 100 000 mPa .s when it reaches at least a portion of the surface of the mold; - allowing the applied curable composition to cure against said solid surface, formed at least by said panel and said mold surface, to produce the joint; and - removing the panel and the joint produced therein from the mold.

The panel is generally a window panel arranged to be mounted on a body. In order to mount the window panel in a body, it is provided with a gasket extending along the periphery of the panel. In the currently known methods, the joint is produced directly on the window panel, either by an extrusion process or by an injection molding process. In the extrusion process, a profiled chain of a polymeric reaction system or a thermoplastic polymer is extruded and deposited on the edge of the window panel by means of a calibrated nozzle guided by means of an automatic handling device. The polymeric reaction system or the thermoplastic material is applied in a pasty or kneadable state, i.e. in a highly viscous state, so as to maintain its shape when applied to the window panel instead of flowing outward. According to US-A-5 362 428, the extruded synthetic resin can have a viscosity on the scale of 300,000 to 10,000,000 mPa.s (= cP), and more preferably on the scale of 600,000 to 3,000,000 mPa.s (at a shear rate of 1 / s) in order to allow the synthetic resin to be formed in a specified manner or to maintain the specified shape until the extruded synthetic resin is cured. An advantage of the extrusion process is that it involves tool costs much lower than the injection molding process but has a number of drawbacks. First of all, the location of the junction line between the start and the end of the extruded profile chain must be finished immediately in an additional procedural step. Second, the extruded chain has a constant cross section profile. Third, it is not possible to extrude around the pointed corners so that, at a location such corners, an additional finishing step is also required. In addition, the surface of an extruded joint has only a modest quality. In order to obtain a window assembly with a gasket of high dimensional accuracy, US-A-5 421 940 describes the extrusion of a thermoplastic polymer on the periphery of the window panel and on an open mold surface that extends further beyond the periphery of the window panel. One difference with the other extrusion processes is that only a portion of the surface of the thermoplastic material is formed by the extrusion die, the other part of this surface is molded against the mold surface. Since the thermoplastic material is partially formed by the extrusion die, it must have a very high viscosity to maintain its shape. A drawback of the method described in US-A-5 421 940 is therefore that the thermoplastic material has to be applied with a sufficiently high pressure on the surface of the mold in order to form the viscous thermoplastic material against the surface of the mold and against the edge of the panel. In order to be able to apply the required pressure on the thermoplastic material in the mold, the extrusion nozzle should be pressed hard against the upper side of the glass panel. In the embodiment illustrated in Figure 5 of the aforementioned patent, wherein not only the front part but also the back part of the joint is molded against the surface of the mold, the extrusion nozzle also has to be adjusted exactly in the space between the surface of the mold and the upper surface of the glass panel. It is evident that the risk of glass breakage is increased by the pressure exerted by the extrusion nozzle on the glass panel. Another drawback of the method described in US-A-5 421 940 is that the pressure that can be exerted on the thermoplastic material in the mold is limited since the material is not injected into a completely closed mold. As a consequence, compared to an injection molding process, the quality of the surface will worsen. Especially when the surface of the mold shows a fine texture, the thermoplastic material may be too viscous to assume this texture. In addition, air bubbles may remain present at the interface between the surface of the mold and the thermoplastic material. In order to ensure that the surface of the mold is completely wetted with the thermoplastic polymer, US-A-5 421 940 teaches the heating of the mold. However, the mold is only heated to a temperature below the temperature of the extruded thermoplastic polymer so that the polymer still remains highly viscous. In addition, when heating the mold, the time of the production cycle increases as the polymer must be allowed to settle before the window assembly can be removed from the mold.

In a reaction injection molding (RIM) process, a curable composition is injected under pressure into a closed mold cavity formed around the periphery of the glass panel. An advantage of said RIM process is that the lower viscous curable compositions can be used (see for example WO 98/14492 which dises preferred viscosities of polyol and isocyanate mixtures of between 150 and 2500 mPa.s at an application temperature). Advantages of said injection molding process are the best surface quality of the joints (mainly due to a much lower viscosity of the injected reactive mixture) and a larger design freedom. Important drawbacks of an injection molding process are however the high tool costs and also the time and effort required to make and modify the injection molds (either when the mold surface is damaged or when a new design is needed) . The molds must in fact be made of a robust material in order to withstand the relatively high temperature and pressure of the process. This appears for example in EP-B-0 355 209 which describes the replacement of elastomeric seals between the surface of the mold and the glass panel by means of a metal ring since the elastomeric seals have the drawback of imperfect seam lines due to the fact that they tend to deform when very high pressure is exerted on them. In addition, a very accurate grinding of the mold is necessary to prevent glass breakage during mold closing and precision adjustment of the contact area between the surface of the mold and the glass panel, so as to avoid spillage of the injected material . These high tool costs generally impose limits on the production capacity of a RIM procedure. An additional drawback of! RIM procedure is that an external release agent must be applied on the mold surface. This not only involves an extra step of the process (a longer cycle time) but also causes defects in the surface in the joint, such as a very low brightness of a high gloss joint, due to the accumulation of this release agent in mold. Another drawback of a RIM process is finally that the mold cavity must show a minimum height so that it can be completely filled, i.e., substantially without spaces, with the curable composition. US-A-6 228 305 dises another additional method for producing a gasket at the periphery of a window panel. According to this method, a glass panel is placed in a lower mold section. Subsequently, a highly viscous (extruded) adhesive is applied on the edge of the window panel and a highly viscous foam material on the mold surface extending along the edge of the window panel. Before the adhesive and the foaming material are fully cured, a pressure is exerted on the adhesive and the foaming material by lowering an upper mold section in the lower mold section in order to form the mold. adhesive and the foam-forming material in the desired shape. Due to the fact that the foaming material and the adhesive are highly viscous, considerable pressure will be exerted on the foam material and the window panel. A drawback of the method described in US-A-6 228 305 is therefore that the mold must again be made from a robust material which results in the same drawbacks as mentioned above for a RIM process (in particular costs of elevated tool, risk of breaking glass, ...). In addition, due to the high viscosity of the molding materials, and the fact that they will even have an increased viscosity when the required pressure is exerted on the molding material, the surface quality will not be as good as the surface quality of the molded articles. by injection, especially not when a fine surface texture should be assumed from the mold surface. In view of the drawbacks of the prior art methods, it is the object of the present invention to provide a new method for producing a panel assembly that allows superior design freedom and better surface quality of the board than that which is obtained by the common extrusion process, without however implying tool costs that are so high for the RIM process. More particularly, the new method should allow to vary the cross-sectional profile of the joint along the periphery of the panel without requiring highly expensive molds. Up to this point, the method according to the invention is a molding method wherein the curable composition has a dynamic viscosity of less than 100 000 mPa.s (at a shear rate of 1 / s) when it reaches at least a portion of the mold surface. In contrast to the known injection molding methods wherein said less viscous curable compositions are used, the curable composition is not injected into a closed mold but applied, either directly or indirectly, to the panel and the surface of the mold by means of an applicator device that moves along the periphery of the panel while applying the curable composition. Since the curable composition has a lower viscosity than the polymers used in the known extrusion processes, a better surface quality can be achieved without having to exert high pressures on the curable composition. In particular, it is possible to assume the surface quality of polished molds (glossy surface) of structured molds (for example sanded mold surfaces) or of textured molds (which show for example a leather texture). Due to the fact that the curable composition is applied by means of a moving applicator device, the curable composition can be applied in an open mold. In a preferred embodiment of the invention, the curable composition is also cured in an open mold or in a mold that is not completely filled with the curable composition. In other words, when the curable composition is cured, the solid surface against which the joint is produced, preferably only partially surrounds this joint so that said portion of the joint surface is allowed to cure in contact with the solid surface while a Additional portion of the joint surface is simultaneously allowed to cure in contact with a gas. According to the invention it has been found that it is not necessary to use a closed mold (such as for example in a RIM process) which molds the less viscous curable compositions into the desired form, but which can be achieved a wide variety of forms also by applying the curable compositions by means of a moving applicator device in an open mold. Compared to the use of a closed mold, the use of an open mold offers considerable advantages. First of all, there is no risk of glass breaking during mold closing, and no precision adjustment of the mold sections is necessary to avoid spillage of applied material. In addition, substantially no pressure or only very little pressure is necessary to apply and mold the curable composition against the solid surface. It is a further preferred embodiment of the method according to the invention, the curable composition is applied and allowed to cure until the joint is produced (i.e., until it can be substantially demolded without causing permanent deformation of the joint) more particularly without exercising a pressure on the surface of the mold that is greater than 500 mbar, preferably without exerting a pressure on the surface of the mold that is greater than 350 mbar, more preferably without exerting a pressure on the surface of the mold that is greater than 150 mbar and more preferably without generating a pressure on the surface of the mold that is greater than 50 mbar.

As a result of such low pressures, the panel does not have to be pressed with a higher pressure on the surface of the mold to avoid instantaneous formation and the surface of the mold does not need to be made of a robust material, such as metal. Instead, it can be made from a softer material, such as for example silicone material. An advantage of such a softer material is that an effective seal is achieved between the mold surface and the panel without having to provide separate seals on the surface of the mold. In addition, some soft materials such as silicones do not adhere to the joint so that an external release agent should not be applied. Finally, it is much easier to make mold surfaces of a softer material than for example metal so that the molds will not only be less expensive but the design thereof can be changed more easily. The silicone molds can be produced, for example, in a master mold. In this way, the damaged molds can be replaced with little expense, and it is also possible, without excessive costs, to provide more molds in order to increase the production capacity. In view of the elastic properties of the mold surface, the master mold must be made exactly as the RIM molds used in the prior art methods. In the method according to the invention, the curable composition can be applied on the surface of the mold, either directly or indirectly, and on the panel, either directly or indirectly. Applying the curable composition directly on the surface of the mold or on the panel means that the curable composition left by the applicator device arrives directly on the surface of the mold respectively the panel. Applying the curable composition indirectly on the surface of the mold or on the panel means that the curable composition leaving the applicator device first reaches a portion of the solid surface against which the joint must be produced (for example only on the panel or on the surface of the mold or optionally in an insert) and subsequently also spreads out in order to cover the entire solid surface against which the joint must be produced. In order to spread the curable composition so as to cover the entire solid surface in which the joint must be produced, the curable composition can flow out onto this surface. Alternatively, or, preferably in additional form, the curable composition may contain a blowing agent and the curable composition is allowed to foam on the surface on which it is applied so that the curable composition is spread to cover the entire solid surface on which the board is produced. In the method according to the invention, the curable composition can thus be applied by means of the applicator device initially only on the panel or in an insert and can subsequently be allowed to flow in and on the mold surface. When it reaches the surface of the mold, that is, when it is applied in the first portion thereof, the curable composition must show the lower viscosity required by the present invention. When the mold surface is further covered, the viscosity may already have increased to a higher value due to curing of the curable composition, especially when a non-visible portion of the joint surface occurs against this additional portion of the mold surface. . In a preferred embodiment, the viscosity of the curable composition nevertheless remains below the upper limits of the present invention until the covering of the surface of the mold with the curable composition is completed. In a preferred embodiment of the method according to the invention, the curable composition is spread over a larger area or wider width before being applied to the solid surface against which the joint must be produced, so that it can be applied (by one or more steps of the applicator device) substantially over the entire solid surface that has to be covered with the curable composition. The curable composition can be spread either in the applicator device and / or after it leaves the applicator device by sprinkling it according to a spray pattern that deviates in one or more directions. By spreading the curable composition before it reaches the solid surface in which the joint is produced, the curable composition can be applied in one or more relatively thin layers while still covering this total solid surface, i.e., the total contact area between the board on one side, and the panel, the surface of the mold and any other solid insert, on the other side. In this way, defects in the surface of the joint can be easily avoided. Furthermore, it has been found that, regardless of the fact that no mold surface is provided for molding the backside of the joint, the thickness of the joint (measured in a direction perpendicular to the large faces of the panel) may be limited, especially when the solid surface on which the joint must be produced shows a relatively pronounced relief or relatively large height differences. In fact, when one or more relatively thin layers are applied, the back of the joint should not be flat but it can follow in a large profile the front side defined by the mold surface and the surface of the panel. In this regard, the curable composition is preferably applied in at least one layer having an average thickness of less than 3 mm, preferably less than 2 mm, more preferably less than 1.5 mm, and more preferably less than 1 mm. The present invention also relates to an assembly of the panel, as described hereinbefore, and is characterized in that it is obtained by the method according to the invention. The gasket in the panel assembly panel according to the invention more particularly has a surface, a portion of which is molded against a solid surface while a second portion of which is produced in contact with a gas. Other features and advantages of the invention will be apparent from the following description of some particular embodiments of the method and assembly of the panel in accordance with the present invention. The reference numbers used in this description are related to accompanying drawings in which: Figures 1 to 3 schematically illustrate a first method according to the invention wherein a joint is produced by two successive spray steps at the edge of a panel glass; Figure 4 shows a different design of a joint that can be produced, by a passage of the applicator device, at the edge of the glass panel; Figures 5 and 6 are similar to Figure 1 but illustrate a different way of spreading the curable composition on the edge of the glass panel and on the mold surface; and Figures 7A to 7C illustrate varied surfaces of the mold that can be used in the methods illustrated in the previous figures. Figure 8 illustrates a varied design of the mold surface; Figures 9 to 11 illustrate a seal adhered to the glass panel and containing an insert; and Figures 12 to 13 illustrate a further method according to the invention wherein the curable composition is foamed to produce the gasket. In the method illustrated in Figures 1 to 3, a gasket 1 is provided by means of a spraying process in a glass panel 2, in particular a glass panel arranged to be mounted in a vehicle opening. The gasket 1 adheres to a portion of the panel 2 and extends along at least a portion of the periphery thereof. Instead of providing the joint in a glass panel, it is also possible to apply it in other types of panels such as a sheet metal or in synthetic panels such as polycarbonate panels, or in solar panels. In addition, the panel may comprise some finishing elements applied at the edge thereof, such as for example a molding layer or a paint layer on the back of the panel or a strip on the front side of the panel. Said strip may adhere to the current panel before producing the joint or may adhere to the panel by means of the joint by itself. When in contact with the panel, it should be considered as a part of the panel. An essential feature of the joint produced in accordance with the present invention is that it has a surface, at least a portion of which is molded against a solid surface, formed not only by the panel (and any insert) but also by a surface printed. The gasket in particular forms an edge molding which acts as a means to close or cover the space between the panel and the edge of the opening where the panel must be mounted. As a result, in a top plan view, viewed in a direction perpendicular to the larger faces of the panel, the joint generally has a surface area smaller than the panel. The glass panel 2 has a first and second major face 3, 4 and a peripheral edge face 5. In the illustrated embodiment, the glass panel 2 is placed with its first major face 3 on the surface 6 of an open mold so that a portion of the mold surface 6 projects beyond the peripheral edge face 5 of the panel. In this way a joint, in particular an encapsulation, having a high dimensional accuracy, will form around at least a portion of the periphery of the panel 2 thus allowing a perfect continuity between the panel assembly and the body. Before placing the panel 2 against the surface of the mold, preferably the first coat of paint is cleaned or given to improve the adhesion of the board to the panel. The mold surface 6 of the mold is formed by an elastic part 8 which is received in a groove in a metal support part 7. The surface of the mold 6 is flush with the first larger surface 3 of the glass panel 2. However, it is clear that it is possible, for example, to form the surface of the mold so as to have a recessed portion located in the front part of the first major surface of the glass panel. In this way the gasket will extend partially over the first major face 3 of the glass panel 2. In order to realize a gasket 1, the portion of the surface 4, 5 of the panel 2 and the surface of the mold 6 in which it must the joint is produced, it is covered with a curable composition. The curable composition is cured and the panel and joint produced therein are removed from the mold. In the method according to the invention, the curable composition is applied by means of an applicator device 9 which moves along at least a portion of the periphery of the panel 2. The curable composition is preferably applied by means of the applicator device directly on both the surface of the mold as in the panel. However, it is also possible to apply the curable composition by means of the applicator device only directly on the surface of the mold or on the panel (or possibly on an insert placed on the surface of the mold or on the panel) and subsequently indirectly. in the remaining part of the solid surface that must be covered with the curable composition. In the latter case, the curable composition must also be spread on the surface of the mold and / or on the surface of the panel in order to cover the entire solid surface against which the joint will be produced. The curable composition can be a non-thixotropic (Newtonian) or thixotropic (non-Newtonian) or liquid material. In order to obtain a better surface quality without having to exert too high a pressure on the curable composition applied on the surface of the mold, the curable composition has a dynamic viscosity, measured at a shear rate of 1 / s, lower at 100 000 mPa.s, preferably less than 75 000 mPa.s, more preferably less than 35 000 mPa.s and more preferably less than 10 000 mPa.s when applied on at least a portion of the surface of the mold (for Newtonian liquids, the dynamic viscosity does not depend on the shear rate and can be determined in accordance with ASTM D445-03). The lower the viscosity, the better the surface quality. In this regard, when it comes to the surface of the mold, that is, when it covers a first portion of the surface of the mold, the curable composition has a dynamic viscosity which is preferably even less than 10 000 mPa.s, more preferably less than 5 000 mPa.s and more preferably less than 2 000 mPa.s. In order to achieve such viscosities, a suitable formulation can first of all be selected for the curable composition. In addition, the dynamic viscosity of a particular formulation can be decreased by increasing the temperature of the curable composition. The curable composition can be applied, for example, at room temperature. However, in order to accelerate the curing reaction, the curable composition can also be applied at a higher temperature, for example at 65 ° C, either on an unheated surface or on a heated surface for example at 45 ° C. When the curable composition is applied directly on the entire surface of the mold, it has the lower viscosity required when applied to the entire surface of the mold. When a first portion of the surface of the mold is first applied, and subsequently is spread over the entire surface of the mold, it may have a higher viscosity when it is spread on the last portion of the surface of the mold (due to the curing reaction). This last portion of the mold surface preferably is a non-visible side of the joint. However, the curable composition also preferably has a viscosity below the upper limits defined above when applied to the last portion of the surface of the mold. In the method according to the invention, use is preferably made of a mold having said shape so that the solid surface against which the joint is cured or produced only partially surrounds the joint in a cross-sectional view thereof. , so that a first portion 25 of the surface of the joint is cured in contact with the surface of the mold and the panel while a second portion 26 of the surface of the joint is cured in contact with a gas 19. This gas 19 generally it will be formed by air surrounding an open mold but can also be formed by air or other gas contained in a housing surrounding for example the entire mold or only the periphery of the panel in which the gasket is to be produced. Compared to the known injection molding process where a curable composition is injected into a closed mold, none or at least considerably less pressure is exerted on the curable composition in the mold. In this way less robust mold materials can be used and an effective seal can be obtained more easily between the surface of the mold and the surface of the panel, even for low viscosity curable compositions. In a particular embodiment of the method according to the invention, the curable composition is applied by means of the applicator device directly on the surface of the mold 6 and on the surface of the panel 2 and is spread from a predetermined distance D (which has no to be constant) on the surface of the mold 6 and a portion of the panel 2. In this way, the entire width of the solid surface can be covered with a layer of the curable composition preferably through maximum three, preferably through maximum two steps of the applicator device, and preferably through a single step of the applicator device. In the embodiment illustrated in Figures 1 to 3, the curable composition is applied by means of a spray nozzle 9 which spreads or disperses a pressurized flow of the curable composition. At the time of spraying the curable composition, it preferably has a dynamic viscosity of less than 10,000 mPa.s, preferably less than 5,000 mPa.s, and preferably less than 2,000 mPa.s (at a shear rate of 1 / s) so that it can be dispersed more easily in fine drops. At the time of spraying the curable composition, preferably it is sprinkled from the nozzle according to a spray pattern, of which at least one transverse dimension W increases towards said solid surface. In particular, it increases over a distance d from the applicator device with at least 0.05 x d, and preferably with at least 0.1 x d. In the embodiment illustrated in Figures 1 to 3, the curable composition is sprinkled according to a conical spray pattern so that its cross section increases in two dimensions. However, flat spray patterns are also possible. Instead of using a spray nozzle, the curable composition can be spread from two or more spray nozzles. In addition, instead of sprinkling the curable composition so that it is spread over a larger surface area, it can also be poured or sprinkled by means of an applicator device where the curable composition is spread by dividing it in the applicator device itself at least. two, preferably at least three individual streams leaving the applicator device through separate openings. Additionally or alternatively, the curable composition may also be spread at one or more elongated outlet openings having a smaller and larger transverse dimension L, the larger transverse dimension L being greater than three times the smallest transverse dimension , preferably greater than five times the smallest transverse dimension and preferably greater than ten times the smallest transverse dimension. The larger transverse dimension and / or the number of openings may be so large that the curable composition leaving the dispersion device does not have to be further spread to cover the entire surface. As illustrated in Figure 5, said applicator device may for example comprise a tube 10 provided with a slit for the curable composition to be poured or sprinkled in the form of a film 15 or a curtain of drops 16. Figure 6 illustrates another device applicator wherein the tube 10 is provided with a row of openings through which individual streams or jets 17 of the curable composition are applied on the surface of the mold and the panel. The individual streams or jets 17 cover the entire surface (either through one or through more passes of the dispersion device) without forming., however, a continuous film due to the fact that the curable composition flows on the panel and mold surface to form a continuous layer thereon. Because the curable composition will usually be a rather viscous liquid, it will normally have to be applied under pressure by means of the applicator device. Preferably, the curable composition comprises a polyurethane reaction mixture, for example a polyurethane reaction mixture as described for example in EP-B-0 379 246 (which is taken as a reference herein) it comprises a polyol and an isocyanate component. The curable composition is preferably formulated to produce an elastomeric polyurethane material having a density greater than 400 kg / m3, and preferably greater than 500 kg / m3. However, lower densities are also possible. In particular, it is possible to add a blowing agent, or a larger amount of blowing agent, so that a foam having in particular a density lower than 400 kg / m3, and in particular lower than 250 kg / m3 will be produced. Nozzles suitable for sprinkling the curable polyurethane composition are described, for example, in EP-B-0 303 305 and EP-B 0 389 014 (which are hereby taken as a reference). The nozzles described in these European patents generate a conical spray pattern. However, in the method according to the invention, it is also possible to use nozzles which generate, for example, a flat spray pattern. The curable composition can be sprayed in such a way that it reaches the surface of the mold and the panel in the form of a film 15 and / or in the form of drops 16. It is preferably sprayed at a sufficiently low pressure to leave the nozzle of the mold. sprinkling in the form of a film 15 which, after a predetermined spray distance, is divided into drops 16 (see figure 1). As illustrated in Figure 5, a film 15 that is divided into drops 16 can also be obtained by means of other dispersion devices, such as a dispersion device comprising an elongated slit through which preferably the curable composition it is released under some pressure. Depending on the distance D from which the curable composition is applied, it therefore reaches the surface of the mold and / or panel in the form of a film 15 and / or in the form of drops 16. The film 15 preferably It has a thickness less than 2 millimeters, and preference less than 1 millimeter, to allow the application of thin layers. The. distance D from which the curable composition is applied is preferably greater than 10 millimeters, and preferably greater than 20 millimeters. In the method illustrated in Figures 1 to 3, two successive layers are sprinkled on the mold and the surface of the panel. As can be seen in Figure 2, only a relatively thin layer is formed on the edge of the glass panel between the second large surface 4 and the peripheral edge face 5. By means of a second spray step, it can also be obtained however, a sufficiently thick layer in that location (see figure 3) without having to fill the mold completely so that the joint does not have a flat top or back side but that follows in a large profile the mold and surface of the panel. In this regard, the layers of the curable composition preferably have an average thickness of less than 3 mm, preferably less than 2 mm, and particularly less than 1.5 mm or even less than 1 mm. The smaller layer thicknesses are also advantageous because they make it possible to produce joints, especially ridges, which have a small thickness (in particular even smaller than the minimum thicknesses that can be obtained through a RIM process). In addition, a better surface quality can be obtained due, for example, to the fact that it is easier to avoid tiny holes. By average thickness, referred to in the present specification, to the volume of curable composition applied on the surface of the mold and on the panel divided between the surface area of the solid surface (including the contact area between the curable composition and the surface of the mold, the panel and any insert) against which the joint is produced (not considering any area or volume of overspray 20). In order to be able to produce the joint 1 through a limited number of steps of the spray or dispersion device, the layer or layers in which the curable composition is applied, preferably have an average thickness greater than 0.1 mm, preferably greater than 0.25 mm, and preferably greater than 0.4 mm. In the method according to the invention, the curable composition is preferably applied and allowed to cure without exerting a pressure on the surface of the mold which is greater than 300 mbar, preferably without generating a pressure on the surface of the mold which is greater at 150 mbar, preferably without generating a pressure on the mold surface that is greater than 50 mbar and in particular even substantially without generating a pressure on the surface of the mold. An important advantage of said low pressures is that the surface of the mold 6 can be made at least partially, but preferably substantially completely, from an elastic material having in particular a Shore A hardness of less than 90, and preferably less than 60. The surface of the mold 6, or in particular the elastic mold part 8, can be made, for example of a silicone material. This can be easily accomplished by molding this part 8 into a mastermold. Due to the elastic nature of the silicone mold part 8, the master mold does not have to be ground very precisely and does not have to be precisely adjusted to make it less expensive to process. An additional advantage of the soft mold part 8, in particular of the silicone mold part 8, is that an effective seal can be obtained between the surface of the mold 6 and the surface of the panel so that burrs do not have to be removed. Preferably, the mold part 8 is made of a self-release material to which the curable composition does not adhere so that an external release agent does not have to be applied. An example of said self-detachment material are the soft silicone materials described above. Other examples are polytetrafluoroethylene (PTFE) type materials. At the edge of the surface of the mold 6 opposite the glass panel 2, the surface of the mold 6 is preferably provided with a cutting edge 11. Due to the pointed top of this edge (radius of curvature preferably less than 1) mm), no amount or only a limited amount of curable composition remains on top of this edge so that a cutting step is not required to separate any overspray on the surface of the mold from joint 1. As shown in FIG. illustrated in Figures 1 to 3, a mask 12 is preferably applied on the panel, particularly on the second major face 4 thereof. After having applied the curable composition, this mask is removed from the panel. The mask 12 is also preferably provided with a cutting edge 13 so that once again a finishing step is not required to separate any overspray 20 on the mask of the polymeric material of the joint 1. The mask 12 can be easily made by molding of the same material as the elastic mold part 8, in particular of a silicone material. Figure 4 illustrates a variant embodiment of the joint 1 that can be obtained by the method according to the invention. In this embodiment, the front side of the joint is still flush with the first major face 3 of the glass panel 2 but no longer extends to the second major face 4 of the panel 2. In fact, it is only adhered to the peripheral edge face 5 of the panel 2. Said design is much easier to obtain with the method according to the present invention than with a RIM procedure, because in view of the small contact area between the joint and the peripheral face, there is a real risk that in a RIM procedure the joint will be detached from the panel when the mold is opened and the panel assembly is removed from the mold. In the method according to the present invention, however, an encapsulation of one side on the peripheral edge of the panel is preferred in view of the material savings that can be obtained. Another advantage of this encapsulation on one side is that the transparent surface area of the glass panel is kept as large as possible. In the embodiment of Figure 4, the second major face 4 of the panel 2 can be easily masked by means of a tape or sheet 14 which extends exactly towards the peripheral edge of the panel 2. The sheet that normally covers the larger faces of A glass panel to protect them from scrapes during transportation and handling, can for example be directly used as a mask, so that no additional step or additional material is necessary to provide the mask. The encapsulation of one side illustrated in Figure 4 further offers the advantage that sharp edges do not have to be covered with the curable composition. Accordingly, for this mode it will be easier to apply the curable composition for the joint only in one layer, i.e., through a passage of the applicator device. Figures 7A to 7C illustrate possible different designs of the elastic silicone mold part 8. As can be seen in Figures 7A and 7B, the location of the cutting edge 11 can be easily varied throughout the extension of the part. of mold 8 so that the joint projects over a variable distance beyond the edge of the glass panel. In Figure 7C, an alternative design of the surface of the mold 6 is illustrated. Below the cutting edge 11, the surface of the mold 6 extends in this embodiment beyond this cutting edge 11. In this way, the free edge of the board will have a very high dimensional accuracy and will provide a reference, on the basis of which the window assembly can be mounted precisely on the body. In order to be able to sprinkle more of the curable composition in the lower cut 18 below the cutting edge 11, the spray nozzle 9 can be rotated in that direction. Of course, the spray nozzle 9 can also be directed towards the glass panel 2 when more curable composition has to be sprayed under the glass panel (for example when the polymeric material has to also extend over a portion of the first larger face). 3 of panel 2). If lower cuts are present on both sides, the spray nozzle can be directed during a first step to one side and during a second step to the opposite side. During both steps, the spray pattern does not have to cover the entire width of the mold and panel surface that will be covered. Figure 8 shows another design of the elastic mold part 8.

The part of the illustrated elastic mold 8 rests not only on the first major face 3 of the panel 2 but also on its peripheral edge face 5. The seal produced on the mold surface and the panel thus forms an encapsulation on one side on the second major face 4 projecting beyond the edge of the panel. In order to obtain a light stable joint, the joint can be made from the light stable curable aliphatic polyurethane compositions described in EP-B-0 379 246. However, a light stable joint can also be obtained by means of an aromatic polyurethane composition by covering it with a light stable layer. This layer can be an in-mold paint, in particular a water-based or solvent-based paint, or a layer of a curable aliphatic polyurethane composition. When mounted in a vehicle opening, the seal obtained through the above-described method can act as a seal against the body. However, it will often not act as a seal but is only intended to provide an aesthetic transition, that is, a seamless continuity, between the window assembly and the body. Because the window assembly usually sticks to the body, a seal between the glass panel and the body is not necessary. However, when that seal is desired, a flexible foam may be applied on the back side of the gasket and / or on the glass panel to fill the space between the window assembly and the body. Said flexible foam can be glued onto the gasket and / or on the panel or can be produced thereon in situ, for example by casting or extruding a foamable polyurethane composition on the backside of the gasket and allowing it to foam to produce the seal 21 (see figure 4). Because an external release agent is not applied to this back part, good adhesion can be obtained. The flexible foam preferably has a density of less than 400 kg / m3, preferably less than 250 kg / m3 and preferably less than 150 kg / m3. The joint obtained in the method according to the invention does not necessarily extend around the entire periphery of the panel. If so, an additional procedural step is not required to terminate any bond between the start and end locations or at the location of the pointed corners. At the time of sprinkling the curable composition from a distance on the surface of the mold, the spray nozzle can follow the periphery of the panel, but preferably moves along each of the sides of the panel and moves forward when it arrives to the corners, preferably interrupting the sprinkling when it arrives or has passed the corner. After being moved to the correct position to sprinkle the next side of the panel (or to sprinkle a second layer of curable composition on the previously sprayed side), the sprinkling starts again and the spray nozzle moves along the next side. At the corners, some overlap may occur, but this does not cause practical problems because the front of the joint remains the same quality and there will usually be a space between the joint and the body. In addition, the board will normally be a quantum compressible. In the method according to the present invention, different types of inserts can be molded into the joint. Examples of such inserts are electrical cables, a mirror support, alarm sensors, switches, "Einfassrahmen", water deflectors, etc. Figure 9 illustrates for example an electrical cable 27 which was placed on the panel before applying the curable composition to be embedded there. The insert can also be placed on the surface of the mold, preferably after having applied a first layer of the curable composition thereon so that the insert is completely embedded in the joint and is not visible. As illustrated in figure 10, an insert, particularly an aesthetic strip 22, can also be placed on the surface of the mold so that it remains visible. The strip 22 can be clamped between raised edges on the surface of the mold so that a groove 23 is formed along both edges of the strip. In the method according to the invention, the penetration of curable composition between the front side of the strip and the mold surface can be very easily avoided. In fact, no pressure is exerted or substantially no pressure on the curable composition. In addition, the surface of the mold can be made of an elastic material that provides an effective seal. Additionally, upright molds may be provided on the surface of the mold, which may also be made of the same soft elastic material so that even rigid inserts between such edges may be easily held. Figure 11 shows an embodiment wherein the insert comprises a prefabricated rim 24 which forms the free edge of the encapsulation. This flange 24 may show different properties to the properties of the joint. For example, it may be softer to provide a seal against the body. Figures 12 and 13 illustrate a particular embodiment of the method according to the invention, wherein use is made of a curable composition which comprises a blowing agent for producing a foam. The foamable composition is poured into a first step, illustrated in Figure 12, on the surface of the mold 6. During this pouring step, the curable composition flows out on the surface of the mold and begins foaming. As illustrated in Figure 13, the surface of the mold 6 and the edge of the panel 2 are not only covered due to the fact that the curable composition flows out, but especially also due to the fact that the volume of the curable composition increases as a result of the foaming reaction. Because the foaming reaction is performed in an open mold, substantially no pressure is generated therein.

Claims (29)

NOVELTY OF THE INVENTION CLAIMS

1. A method for producing a panel assembly, in particular a panel assembly for use in a vehicle opening / gap, comprising a panel 2 and a joint 1, which is adhered to the panel together, extends along the length of the panel. at least a portion of its periphery and having a surface, at least a portion 25 of which is molded against a solid surface, the method comprises the steps of: providing a mold 7, 8 having at least one surface of mold 6; placing the panel 2 and the mold surface 6 against each other; applying a composition to produce said joint 1, by means of an applicator device 9 moving along at least said portion of the periphery of the panel 2 at the time of applying the composition in the open mold, directly or indirectly on the mold surface and directly or indirectly on said panel; producing the gasket 1 from said composition against said solid surface, formed at least by said panel 2 and by said mold surface 6; and removing the panel 2 and the joint 1 produced on it from the mold 7, 8, characterized in that said composition is a curable composition that is allowed to cure against said solid surface to produce the joint 1 and which has a dynamic viscosity, measured at a shear rate of 1 / s, less than 35,000 mPa.s when it arrives on at least a portion of the mold surface.

2. The method according to claim 1, further characterized in that the curable composition is applied and allowed to cure until the joint is produced without exerting a pressure on the mold surface 6 which is greater than 500 mbar, preferably without exerting a pressure on the mold surface which is greater than 350 mbar, preferably without exerting a pressure on the mold surface which is greater than 150 mbar and particularly without exerting a pressure on the mold surface which is greater than 50 mbar

3. The method according to claim 1 or 2, further characterized in that when the curable composition is cured, said solid surface only partially surrounds the joint 1 so that said portion 25 of the surface of the joint is allowed to cure in contact with said solid surface while an additional portion 26 of the surface of the polymeric material 1 is allowed to cure simultaneously in contact with a gas 19 until the joint is produced.

4. The method according to any of claims 1 to 3, further characterized in that when it reaches said portion of the mold surface 6, the dynamic viscosity of the curable composition is less than 10 000 mPa.s and preferably less than 5,000 mPa.s.

5. The method according to any of claims 1 to 4, further characterized in that said curable composition is applied by means of said applicator device 9 directly on said mold surface 6 and also directly on said panel 2. 6.- The method according to any of claims 1 to 5, further characterized in that the curable composition is spread in at least one direction in said applicator device 9 before leaving the applicator device, the curable composition is preferably spread on the applicator device by dividing it in the applicator device in at least two, preferably at least three individual streams 17 emerging from the applicator device and / or by spreading at least one stream of the curable composition in said applicator device 9 so that, upon exiting the applicator device , said current has a smaller transverse dimension and a larger one, the dimension larger cross L n is greater than three times the smallest transverse dimension, preferably greater than five times the smallest transverse dimension and particularly greater than ten times the smallest transverse dimension. 7. The method according to any of claims 1 to 6, further characterized in that the applicator device 9 is maintained at a distance D from said solid surface when the curable composition is applied thereon, and the curable composition is sprayed by means of the applicator device onto said solid surface. 8. The method according to claim 7, further characterized in that the curable composition is sprinkled according to a spray pattern, at least a transverse dimension W of which increases to said solid surface, said at least one transverse dimension W in particular increases over a distance d from the applicator device with at least 0.05 xd, and preferably with at least 0.1 x d. 9. The method according to claim 7 or 8, further characterized in that the distance D from which the curable composition is sprayed is greater than 10 mm and preferably greater than 20 mm. 10. The method according to any of claims 7 to 9, further characterized in that the curable composition is sprayed in the form of a film 15 and / or in the form of drops 16 on said solid surface. 11. The method according to claim 10, further characterized in that said film 15 has a thickness of less than 2 mm, and preferably less than 1 mm. 12. The method according to any of claims 1 to 11, further characterized in that the curable composition is applied in at least one layer on said solid surface, which layer has an average thickness of less than 5 mm, preferably! less than 3 mm, preferably less than 2 mm and particularly less than 1 mm. 13. The method according to any of claims 1 to 12, further characterized in that the curable composition is applied in at least one layer on said solid surface, which layer has an average thickness greater than 0.1 mm, preferably higher at 0.25 mm and preferably greater than 0.4 mm. 14. The method according to any of claims 1 to 13, further characterized in that said mold surface 6 is formed at least partially but preferably substantially completely from an elastic material having in particular a Shore A hardness of less than 90 and preferably less than 60, said elastic material is in particular a molded silicone material. 15. The method according to any of claims 1 to 14, further characterized in that said mold surface 6 is formed through a self-detachment material that does not require coating of a release agent to allow the removal of the As the gasket of the mold surface, the self-detachment material is in particular a silicone or PTFE material. 1

6. The method according to any of claims 1 to 15, further characterized in that the panel 2 has a first 3 and a second major face 4 and a peripheral edge face 5 and the panel 2 and the mold surface 6 is they place against each other in such a way that said mold surface 6 engages with the first major face 3 of the panel 2 and has a portion which projects beyond its peripheral edge face 5. 1

7. The method of compliance with claim 16, further characterized in that a cutting edge 11 is provided on said portion of the mold surface 6 which projects beyond the peripheral edge face 5 of the panel 2, said cutting edge 11 forms a first edge of the joint 1. 1

8. The method according to claim 16 or 17, further characterized in that the second major face 4 of the panel 2 is provided with a mask 12 which is removed after having applied the curable composition and the l forms a second edge of the joint 1. 1

9. The method according to claim 18, further characterized in that said mask 12 is formed by a sheet 14 or a tape which adheres removably to the second major face 4. of panel 2 and which extends substantially towards the peripheral edge face 5 of panel 2. 20. The method according to any of claims 1 to 19, characterized in that before applying said curable composition, first a mold paint is applied at least on said mold surface 21. The method according to any of claims 1 to 20, further characterized in that said curable composition is applied in at least two layers. 22. The method according to claim 21, further characterized in that said curable composition comprises a first curable composition, which is used to apply a first layer, and an additional curable composition, which is used to apply an additional layer on In the first layer, the additional curable composition is preferably a mixture of reactive aromatic polyurethane. 23. The method according to any of claims 1 to 22, further characterized in that after having produced the seal 1, a flexible foam arranged to form a seal 21 is applied on a back side of the seal 1 and / or on panel 2, the flexible foam has a density of less than 400 kg / m3, preferably less than 300 kg / m3 and preferably less than 200 kg / m3. 24. The method according to any of claims 1 to 23, further characterized in that said curable composition comprises a polyurethane reaction mixture formulated to produce an elastomeric polyurethane material having a density greater than 400 kg / m3, and preference greater than 500 kg / m3. 25. The method according to any of claims 1 to 23, further characterized in that said curable composition is formulated to produce a foam, having in particular a density lower than 400 kg / m3, and particularly lower than 250 kg / m3 , the curable composition preferably comprises a blowing agent and the curable composition is preferably left to foam on said solid surface to produce the polymeric foam. 26.- The method according to any of claims 1 to 25, further characterized in that an insert 22, 24, 27 is fixed to the panel by covering the insert at least partially with the curable composition when the curable composition is applied to produce the joint 1. 27.- The method according to any of claims 1 to 26, further characterized in that said application step comprises the step of letting the curable composition flow out on said solid surface. 28.- A panel assembly, in particular for use in a vehicle opening / gap, comprising a panel 2 and a joint 1 adhered to a portion of the surface of said panel and extending along at least a portion of its periphery, characterized in that the panel assembly is obtained through the method of any of claims 1 to 27 and the joint 1 has a surface, a portion 25 of which is produced against a solid surface while a portion additional 26 of which is produced in contact with a gas 19. 29.- The panel assembly in accordance with the claim 28, further characterized in that said additional portion 26 of the surface of the joint 1 is a free-forming surface, in particular a sprinkled surface.