A laminated glazing with weight reduction and a method to manufacturing thereof

Abstract

The present invention relates to a method to manufacture a curved glazing wherein the method comprises providing a plastic panel (11) and at least one glass sheet (12).

Description

A LAMINATED GLAZING WITH WEIGHT REDUCTION AND A METHOD TO MANUFACTURING THEREOFFIELD OF THE INVENTION

[0001] The application relates to a method for manufacturing a curved glazing comprising a plastic panel and laminated inbetween thin glass sheets. In addition, the application relates to a lightweight vehicle glazing or a lightweight vehicle trim element manufactured by the said method.BACKGROUND OF THE INVENTION

[0002] As automotive manufacturers work to meet government regulations for fuel efficiency and emissions, as well as to provide the environmentally friendly vehicles that the public is increasingly demanding, we are seeing the total glazed area of the vehicle increase. Part of the motivation is weight reduction. There are more and more vehicles, for example with glass roofs. Moreover the more glass used in vehicles gives the vehicle more airy and luxurious aesthetic look and design.

[0003] However, even more glass used in vehicles in order to reduce the total weight, there is still a need of reducing weight for vehicles, especially electric vehicles since increasing battery size is not feasible to improve range. Moreover, the more heavy a vehicle is also means more CO2 emissions that very much adversely affect the environment. On top of that given the emissions during the production of such glass glazings, it is very important to reduce the emissions during the production.

[0004] 0ne approach to reducing the weight of motor vehicle glazing is the use of plastic panels instead of glass sheets. However, compared to glass sheets, plastic panels have some disadvantages, in particular significantly low scratch resistance such that the replacement of substantial parts of motor vehicle glazing by plastic panels has, to date, not been possible.

[0005] To solve the disadvantages of using plastic panels, it is proposed that the plastic panels are laminated inbetween thin glass sheets. Glass sheets being the outer surface element of the glazing not only solves the scratch resistance issue of plastic panels but also provides a more aesthetically pleasing view to the glazings.

[0006] However, traditionally the glass sheets are bended at high temperature furnaces which costs considerably high and the annealing or tempering of glass sheets also require high temperatures. Given the fact that the thickness of the glass is not so dependent on the energyand temperature requirements of the bending furnaces, the costs are pretty much similar to the bending of the traditional glass glazings.

[0007] Furthermore, shaping of the plastic panels is conventionally realized by injection molding which also requires high temperatures and pressures, i.e., high costs. On top of that since the Young modulus of plastic panels are much lower than the Young modulus of glass, shaped plastic panels tend to change their shapes due to the exposed high temperatures, especially when used in vehicles.

[0008] In the conventional methods, the glass sheets are bonded to the plastic panels by using adhesives. When a glass sheet is bent, problems may occur relating to the strain exerted on a bonding interface between the plastic panel and the glass sheet by the bending process. Consequently, a detachment or breakage of the glass sheet may occur. Similar problems may occur when a glass sheet comprises a hole for receiving a functional element such as a display, an air vent, or a rotary knob. The sheet is weakened due to the hole, and the stress in the sheet around the hole may exceed critical values with the consequence of unwanted deformation or even breakage.

[0009] Therefore, although a light weight glazing may be realized with using plastic panels laminated inbetween thin glass sheets, the conventional methods to produce such requires multiple processes and huge energy requirements due to required high temperatures. Additionally, conventional bonding of glass sheets and plastic panels to be used as vehicle glazings do not have the required mechanical strength.

[0010] Automotive glazings such as in WO2021116984 comprise two glass sheets and a reinforcement layer made of polycarbonate laminated inbetween the glass sheets and the bonding of polycarbonate layer and the glass sheets is realized by use of adhesives. The glass sheets are thinner than standard glazings and since the polycarbonate layer is lighter than glass, the total weight of the glazing is reduced compared to the standard glazings.[OO11]US2O17O129219 describes a glazing comprising a polycarbonate layer and a thin glass sheet and additionally a second thin glass sheet that the polycarbonate layer is laminated inbetween, the glass sheets are non-prestressed. Such glazings are also light weight compared to standard glazings, however, the glazing has to be almost flat since the thin glass sheet is non-prestressed and prone to bending.

[0012] EP1577084 describes a laminated plastic glazing comprising a polycarbonate pane and an acrylate pane fixed together by polyurethane layer and an infrared protection foil laminated inbetween.

[0013] It is known from WO2015188982 that a composite glazing comprising a polycarbonate and / or a PMMA panel and a non-tempered thin glass sheet laminated together, wherein the plastic panel is injected.

[0014] It is also known from W02020236306 that a laminate comprising a polycarbonate substrate coated with UV protective coating.

[0015] US20220288893 discloses lamination of glass sheets with an adhesive layer thinner than the glass sheets in a low temperature than the conventional glass bending techniques.

[0016] US20150111016 discloses lamination of glass sheets with a multiple-layer interlayer comprising conventional interlayers that the interlayer bonds the glass sheets.

[0017] None of the prior art above suggest a solution to the issues during the manufacture / assembly step of the glazing. There is still a need for a method to manufacture such plastic-glass glazings with low cost and in less time with more durability.SUMMARY OF THE INVENTION

[0018] The goal of the present invention is to provide a method to manufacture a lightweight laminated curved glazing and also to eliminate the aforementioned problems.

[0019] One aspect of the present invention relates to a lightweight vehicle glazing comprising a plastic panel laminated inside thin glass sheets. As the density of the plastic panel is lower than the glass, total weight of the glazing is lighter by minimum 20% of the weight of the corresponding conventional glazings and the weight reduction may go up to 50%, the use of thin glass as the glass sheets also helps on the weight reduction.

[0020] Another aspect of the present invention relates to the reduction of energy consumption as the fuel consumption or the electricity consumption of the vehicle thanks to the light weight glazing. The lightweight glazing used in electric vehicles enables a tremendous extension of the range of the vehicle with the same battery capacity.

[0021] One further aspect of the present invention relates to a glazing with texture of a glass since the skin of the glazing is composed of thin glass sheets. Therefore the aesthetics of the conventional glass glazing is not compromised by the weight reduction and also the glazing produced by the method of the present invention is resilient to the scratches thanks to theglass skin. Additionally the glass skin of the glazing is helping the aerodynamics of the vehicle, thereby enabling a reduction in the CO2 emissions.

[0022] 0ne further aspect of the present invention relates to a highly rigid vehicle glazing with a high impact resistance that the glazing produced by the method of the present invention. Thanks to the high impact resistance of the plastic panel, the glazing produced by the method of the present invention has more mechanical strength than the conventional glass glazings.

[0023] 0ne further aspect of the present invention relates to the thermoforming of the glazing that the curvature of the glazing is realized by thermal shaping under relatively low temperatures. Therefore the method of the present invention eliminates the need for the high temperature furnaces for the production of lightweight glazings indicating reduction of CO2 emissions during production.

[0024] 0ne further aspect of the present invention relates to the reduction of the production costs thanks to the thermally shaping the glazing under relatively low temperatures than the conventional glass bending temperatures. Thermoforming process is conducted under temperatures of 250°C which is much lower than the conventional glass bending temperatures, thus the reduction of the heating costs can go up to four times lower than the conventional ones. Moreover, such use of low temperatures provides low cycle time in production, which also causes more cost reduction.

[0025] 0ne further aspect of the present invention relates to the reduction of the production times since the glazing is laminated at the same time of the thermally shaping of the glazing thanks to the method of the present invention. The method of the present invention offers shaping the glazing at the same time as laminating the glazing, therefore two different process are now merged with the present invention that the time required to produce the same glazing is substantially reduced compared to the known methods.

[0026] The method of the present invention comprises the steps of providing a flat plastic panel and flat thin glass sheet(s), assembling the plastic panel and the thin glass sheets preferably by interlayers inbetween the plastic panel and the thin glass sheets, heating the assembly via a heating means and then shaping the heated assembly via a bending means. In a version of the method of the present invention, the plastic panel may be heated and shaped alone and the thin glass sheet(s) are fixed / bonded to the shaped plastic panel afterwards. Since the shaping / bending are conducted under low temperatures in both versions of themethod, the benefits mentioned above are substantially achieved in the same way in both versions of the method.

[0027] Thicknesses of the plastic panel and the thin glass sheets can be selected in order to achieve the desired glazing. Achieving a glazing with high mechanical strength and scratchresistant features may be realized by selecting thinner glass sheets and thicker plastic panel. For example, the thickness of the plastic panel is twice of the total thickness of the thin glass sheets, or even three times of the latter. In one embodiment of the present invention, the thickness of the plastic panel is equal to at least the thickness of the glass sheets used in conventional laminated glazings.

[0028] In different embodiments of the transparency of the plastic panel and also its color may be selected according to the desired application. The cost of producing plastic panel with different colors or light transmission rates are much more cheap than achieving the same with glass sheets, therefore the present invention also enables cost reduction for the glazings with different parameters.

[0029] In different embodiments of the present invention, the glazing may comprise at least one thermal management coatings such as low-emissivity coatings and so on. Since the glazing comprises thin glass sheets, it is convenient to apply the said coatings on the glass surfaces.

[0030] In further embodiments of the present invention, the glazing may comprise a functional element such as a liquid crystal based dimming layer or a display and so on.

[0031] The method of the present invention, as can be seen from the different embodiments, provides countless number of variations that serves manufacturing of a light weight laminated glazing with less costs and also provides extra benefits mentioned above.

[0032] In addition to all above, the method of the present invention provides environmental benefits since the energy requirements and CO2 emissions are decreased significantly.BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The invention will now be described further, by way of examples, with reference to the accompanying drawings, wherein like reference numerals refer to like elements in the various figures. These examples are provided by way of illustration and not of limitation. The drawings are a schematic representation and not true to scale. The drawings do not restrict the invention in any way. More advantages will be explained with examples. A betterunderstanding of the present invention will be added upon reference to the following description in conjunction with the accompanying drawings.

[0034] Fig .la to Fig. lb are representative of one embodiment of the present invention.

[0035] Fig ,2a to Fig.2c are representative of one another embodiment of the present invention .

[0036] Fig ,3a to Fig.3b are representative of one embodiment of the present invention.

[0037] Fig.4 is a schematic view of one embodiment of the present invention.

[0038] The elements illustrated in the figures are numbered as follows:I. GlazingII. Plastic panel12. Glass sheet13. Interlayer14. Thermoplastic componentH. Heating meansB. Bending meansDETAILED DESCRIPTION OF THE INVENTION

[0039] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims.

[0040] While some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0041] As used herein, spatial ordirectional terms, such as "inner", "outer", "above", "below", "top", "bottom", and the like, relate to the invention as it is shown in the drawing figures. However, it is to be understood that the invention can assume various alternative orientations and, accordingly, such terms are not to be considered as limiting. Further, all numbers expressing dimensions, physical characteristics, processing parameters, quantities of ingredients, reaction conditions, and the like, used in the specification and claims are to be understood as being modified in all instances by the term "about". Accordingly, unlessindicated to the contrary, the numerical values set forth in the following specification and claims are approximations that can vary depending upon the desired properties sought to be obtained by the present invention.

[0042] Moreover, all ranges disclosed herein are to be understood to be inclusive of the beginning and ending range values and to encompass any and all subranges subsumed therein. For example, a stated range of "1 to 10" should be considered to include any and all subranges between (and inclusive of) the minimum value of 1 and the maximum value of 10; that is, all subranges beginning with a minimum value of 1 or more, e.g. 1 to 6.1, and ending with a maximum value of 10 or less, e.g., 5.5 to 10. Further, as used herein, the terms "deposited over" or "provided over" mean deposited or provided on but not necessarily in surface contact with. For example, a coating "deposited over" a substrate does not preclude the presence of one or more other coating films of the same or different composition located between the deposited coating and the substrate.

[0043] Where the term "comprising" is used in the present description and claims, it does not exclude other elements or steps. Where an indefinite or definite article is used when referring to a singular noun e.g. "a" or "an", "the", this includes a plural of that noun unless something else is specifically stated. In this document, "configured to (or set to)" may be interchangeably used in hardware and software with, for example, "appropriate to", "having a capability to", "changed to", "made to", "capable of", or "designed to" according to a situation. In any situation, an expression "device configured to do" may mean that the device "can do" together with another device or component.

[0044] Furthermore, the terms first, second and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequence, either temporally, spatially, in ranking or in any other manner. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. When it is described that a constituent element (e.g., a first constituent element) is "(functionally or communicatively) coupled to" or is "connected to" another constituent element (e.g., a second constituent element), it should be understood that the constituent element may be directly connected to the another constituent element or may be connected to the another constituent element through another constituent element (e.g., a third constituent element).

[0045] I n the following description, unless otherwise specified, expression "substantially" or "around" or "proximity" or "close to" preferably mean to within 10%, preferably to within 5% i.e., in this context the terms should be understood as in the range of ± 10%, even more ± 5%. Tolerance may be selected depending on the nature of the intended applications.

[0046] I n the following description, unless otherwise specified, expression "liquid adhesive", "optical coupling material", "optical resin", "optical coupling adhesive", "optical clear adhesive" and "liquid resin" are used interchangeably, further expression "functional film", "film", "electrically powered functional film" and "electrical functional film" are used interchangeably, further expression "flow", "fluidic flow", "liquid flow" and "liquid adhesive flow" are used interchangeably, further expression "primary part" and "hard component" are used interchangeably, further expression "secondary part" and "soft component" are used interchangeably, further expression "glazing" and "curved glazing" and "vehicle glazing" are used interchangeably, further expression "glass sheet" and "thin glass sheet" and "first glass sheet" and "second glass sheet" are used interchangeably.

[0047] According to one example of the present invention, the Fig.l (a, b, c) shows the method of production of a curved glazing. In Fig.2 (a, b) shows another embodiment of the present invention.

[0048] The method to manufacture a curved glazing (1) disclosed in the present invention, comprises the steps of providing a plastic panel (11) having a first and second main surfaces, wherein the plastic panel (11) comprises at least a structural layer having a Young modulus in the range of 0.25 to 3 GPa, preferably 1 to 3 GPa. providing at least one glass sheet (12) wherein each of the glass sheets (12) are chemically tempered, assembling the glass sheet (12) on one of the main surface of the plastic panel (11) to form a flat assembly, heating the flat assembly by a heating means (H) at a temperature in the range of 120 to 250 C, bending the flat assembly by a bending means (B) to form the curved glazing (1).

[0049] The method to manufacture a curved glazing (1) disclosed in the present invention, comprises the steps ofproviding a plastic panel (11) having a first and second main surfaces, wherein the plastic panel (11) comprises at least a structural layer having a Young modulus in the range of 0.25 to 3 GPa, preferably 1 to 3 GPa. heating the plastic panel (11) by a heating means at a temperature in the range of 120 to 250 C, bending the plastic panel (11) by a bending means (B) to form a curved plastic panel (11), providing at least one glass sheet (12) wherein each of the glass sheets (12) are chemically tempered, assembling the glass sheet (12) on one of the main surface of the curved plastic panel (11) to form the curved glazing, preferably by cold bending of the glass sheet (12).

[0050] The methods of the present invention focus on the thermal shaping of the plastic panel (11) and the curved glazing (1). The plastic panel (11) in the above embodiments can be shaped with or without the glass sheets (12) provided on. In the preferred version of the present invention, the glass sheets (12) are provided on the main surfaces of the plastic panel (11) by one glass sheet (12) on each main surface of the plastic panel (11) and then heat is applied onto the assembly and then the assembly is shaped / bent accordingly. The plastic panel (11) have a Young modulus of 0.25 to 3 GPa, preferably 1 to 3 GPa, more preferably 1.8 to 2.8 GPa in order to be shaped comfortably with the heat treatment, preferably heat treatment under low temperature, lower than 250°C and also provide required rigidity to the curved glazing (1). The heat treatment is applied at a relatively low temperatures than the standard glass bending temperatures. The given ranges of the Young modulus of the plastic panel (11) should be understood as the total Young modulus of the whole plastic panel (11) that the plastic panel (11) may comprise different layers with Young modulus different than the given range and the total Young modulus of the plastic panel (11) as a whole is in the given range.

[0051] The heating means (H) to heat the assembly may be any heating means (H) suitable for the purpose, such as IR heating means or other resistive heating means. The assembly is heated up to softening point of the plastic panel (11) in order to shape the assembly to the required shape. The heating temperatures are up to 250°C which are very much lower than the conventional glass bending temperatures, and the preferred heating temperature is in the range 120°C to 180°C.

[0052] Curved glass sheets (12) may be formed by first heating a glass sheet (12) to a temperature above the softening point of the glass sheet (12). Subsequently the glass sheet (12) may be deformed by either actively bending the glass sheet (12) using a bending device (B) or by letting the glass bend due to its own weight. Alternatively, cold forming processes may be used when bending glass sheets (12) in the case of thin glass sheets (12). These processes are known to consume less energy and time. In a cold forming process, a glass sheet(12) is typically bent at room temperature on a curved frame so that the bending of the plastic panel (11) is possible without the glass sheets (12). After bending the glass sheet (12), e.g., when a curvature of the glass sheet (12) corresponds to a curvature of the curved frame, the glass sheet (12) is strained and tends to gradually take back its initial shape. Therefore, the bent glass sheet (12) typically needs to be mechanically fixed to the curved frame after bending to retain the curvature ofthe glass sheet (12). In the method of the present invention, cold bended thin glass sheets (12) are fixed / bonded to the plastic panel (11), therefore the curvature of the glass sheet (12) is fixed. Therefore the glass sheets (12) may be preformed / preshaped prior to the fixation with the plastic panel (11) or the glass sheets (12) may be bended actively via the bending means (B) during the fixation to the plastic panel (11) or the glass sheets (12) may be bended together with the plastic panel (11) by the heating means (H).

[0053] The bending means (B) to shape the plastic panel (11) and the assembly may be one of the means used in thermoforming process such as vacuum-forming, pressure-forming or mechanical-forming. In the preferred embodiments, the bending means (B) is a means of pressure-forming or mechanical-forming as the shaping of the assembly to be used as a vehicle glazing (1) is more convenient with such means.

[0054] In another embodiment of the method of the present invention, at least one interlayer(13) is provided inbetween the plastic panel (11) and the glass sheet (12). In another version of this embodiment of the method of the present invention, the interlayers are chosen amongst PVB, EVA, TPU, OCA, TPE, adhesives or PU based material. Such interlayers (13) allow low temperature lamination.

[0055] In another embodiment of the method of the present invention, at least one glass sheet (12) is provided on each main surfaces of the plastic panel (11). Therefore, the method of the present invention provides production of a glazing (1) comprising at least one plasticpanel (11) and at least one glass sheet (12) and in the preferred embodiment, the glazing (1) comprises two glass sheets (12) and interlayers (13) inbetween.

[0056] In another embodiment of the method of the present invention, the plastic panel (11) has a thickness in the range of 1 mm to 50 mm, preferably the high limit is 20mm, even more preferably the high limit is 10mm, and specifically the high limit is 5mm. As the most plastic panels (11) suitable for thermoforming have lower density from the glass, thicker plastic panels (11) than the standard glasses used in vehicles can be used. Such applications allow improving the strength of the curved glazing (1).

[0057] In another embodiment of the method of the present invention, the glass sheets (12) have a thickness lower than 1.5 mm, preferably lower than 1.1 mm, even more preferably lower than 0.9 mm. In order to reduce the weight of the curved glazing (1), thinner glass sheets (12) are employed. In the preferred version of this embodiment, the glass sheets (12) have a thickness of maximum 0.5mm.

[0058] In another embodiment of the method of the present invention, the thickness of the plastic panel (11) is equal or greater than the twice of the total thickness of the glass sheets (12), preferably equal or greater than three times of the total thickness of the glass sheets (12). To provide the rigidity of the curved glazing (1), the thickness of the plastic panel (11) is at least twice thicker than the total thicknesses of the glass sheets (12). For example, when the thickness of one glass sheet (12) is 0.5mm, the thickness of the plastic panel (11) is at least 2mm or even 3mm.

[0059] In another embodiment of the method of the present invention, the thicknesses of the plastic panel (11) and the glass sheets (12) are inversely correlated. For reducing the weight of the curved glazing (1) and providing required strength of the curved glazing (1), the thicknesses of the plastic panel (11) and the glass sheets (12) are chosen as inversely proportional to each other. In other words, the thinner the glass sheets (12) the thicker the plastic panel (11).

[0060] In another embodiment of the method of the present invention, the plastic panel (11) further comprises a further structural layer having a Young modulus lower than the Young modulus of the structural layer. The plastic panel (11) may comprise further layers with lower Young modulus that facilitates the bending of the plastic panel (11).

[0061] In another embodiment of the method of the present invention, the material of the plastic panel (11) is a polycarbonate based material. Polycarbonate based materials aresuitable for thermoforming and can also be transparent at visible light, therefore the plastic panel (11) is chosen to be made of polycarbonate based material that the curved glazing (1) can be used as a vehicle glazing (1). Polycarbonate based materials are also capable of providing adequate strength.

[0062] In another embodiments of the present invention, the thickness of the plastic panel (11) is larger than the thickness of the glass sheets (12).

[0063] I n the preferred embodiments, the plastic panel (11) should be understood as a solid layer next to the glass sheets (12) that needs to bended by application of heat and it does not have any adhesive properties that the plastic panel (11) cannot adhere to glass sheets (12) itself. Furthermore, the plastic panel (11) should not be confused with interlayers functioning as bonding layers inbetween the glass sheets (12), such as PVB, EVA, TPU, OCA, TPE, adhesives or PU based material. The plastic panel (11) itself does not have any bonding function of the glass sheets (12).

[0064] In another embodiment of the method of the present invention, the interlayers (13) are chosen amongst PVB, EVA, TPU, OCA, TPE, adhesives or PU based material.

[0065] In another embodiment of the method of the present invention, the plastic panel (11) has a light transmission of higher than 50%. The plastic panel (11) has a light transmission of higher than 50%, the light being preferably the visible light and transmission value is the average value on the said light band. The curved glazing (1) needs to be transparent at visible light at a certain level when it is used as a glazing in a vehicle. By manipulating the light transmission of the plastic panel (11), the desired level of transparency of the curved glazing (1) can be achieved.

[0066] In another embodiment of the method of the present invention, the plastic panel (11) further comprises light diffusing elements (not shown in figures). The plastic panel (11) comprises light diffusing elements to diffuse the light projecting on the curved glazing (1). Therefore, in the case of the curved glazing (1) being for instance a roof of a vehicle, sunlight will be diffused on the plastic panel (11) that even under the direct sunlight, the passengers inside the vehicle will not be disturbed.

[0067] In another embodiment of the method of the present invention, the area of the main surfaces of the plastic panel (11) is larger than the area of the glass sheets (12). The area of one of the main surfaces of the plastic panel (11) is larger than the surface area of one of the glass sheets (12). In different words, the edges of the plastic panel (11) protrudes towards toexternal environment that the whole surface of the glass sheets (12) may bond to the plastic panel (11). Such extension of the plastic panel (11) not only protects the edges of the glass sheets (12) from external effects but also helps the rigidity of the curved glazing (1).

[0068] In another embodiment of the method of the present invention, the method further comprises a step of injecting at least one thermoplastic component (14) on at least a part of the periphery of the curved glazing (1). After assembling the curved glazing (1), at least one thermoplastic component (14) is injected on at least a part of the periphery of the curved glazing (1), the injection can be provided in a plastic injection mold. The material of the thermoplastic component (14) can be TPE or PU as those are widely used in automotive industry, moreover thermoset materials are also compatible with the method of the present invention. In different version of this embodiment, the said injection encapsulates the curved glazing (1), in other words, injection is realized on the whole periphery of the curved glazing(I). The injected thermoplastic component (14) protects the open edges of the plastic panel(II) from the unwanted effects of the environment, for example protecting the plastic panel(11) from direct UV light. Moreover, the injected thermoplastic component (14) may also assist keeping the shape of the curved glazing (1) and prevent the tendency to became flat. Additionally the injected thermoplastic component (14) may also function to improve the aesthetics of the curved glazing (1).

[0069] In another embodiment of the method of the present invention, the method further comprises a step of laminating a functional element (not shown in figures) in between the plastic panel (11) and at least one of the glass sheets (12). Glazings (1) used in vehicles are now having more functions than ever, some examples of such functional elements are like liquid crystal films used as a dimming layer or display, solar cells, lighting units and so on. During the manufacturing of the curved glazing (1), the relevant functional element(s) is also laminated inbetween the plastic panel (11) and the glass sheets (12).

[0070] In another embodiment of the method of the present invention, the method further comprises a step of applying at least one thermal management coating on the glass sheets(12) before or after the assembly of the curved glazing (1). The glass sheets (12) are coated with thermal management coating such as low emissivity coating or silver based coatings. The said coatings can be applied before the assembly of the curved glazing (1) or after the assembly of the curved glazing (1). With this embodiment, thermal management is enabledon the curved glazing (1) that the in the case of curved glazing (1) being a roof of a vehicle, the passenger will experience comfort during very hot or cold days.

[0071] In another embodiment of the present invention, the curved glazing (1) manufactured according to the method and embodiments above is used as a vehicle glazing (1). The vehicle glazing (1) can be a windshield, sidelite, roof, backlite, quarterlite, rear door fix of a vehicle it can also be used as a trim element used in vehicles, such as console, appliques or any.

[0072] With this invention, specifically by the production of a lightweight glazing (1) under low temperatures, the lightweight glazing (1) is realized in a sustainable way and also with a significant cost reduction since multiple operation steps are combined in the method of the present invention.

[0073] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive. The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention may be practiced in many ways. The invention is not limited to the disclosed embodiments.

Claims

CLAIMS1. A method to manufacture a curved glazing (1) wherein the method comprises the following steps; providing a plastic panel (11) having a first and second main surfaces, wherein the plastic panel (11) comprises at least a structural layer having a Young modulus in the range of 0.25 to 3 GPa, providing at least one glass sheet (12) wherein the glass sheets (12) are chemically tempered, assembling the glass sheet (12) on at least one of the main surface of the plastic panel (11) to form a flat assembly, heating the flat assembly by a heating means (H) at a temperature in the range of 120 to 250 C, bending the flat assembly by a bending means (B) to form the curved glazing (1).

2. A method to manufacture a curved glazing (1) wherein the method comprises the following steps; providing a plastic panel (11) having a first and second main surfaces, wherein the plastic panel (11) comprises at least a structural layer having a Young modulus in the range of 0.25 to 3 GPa, heating the plastic panel (11) by a heating means (H) at a temperature in the range of 120 to 250 C, bending the plastic panel (11) by a bending means (B) to form a curved plastic panel (11), providing at least one glass sheet (12) wherein the glass sheets (12) are chemically tempered, assembling the glass sheet (12) on one of the main surface of the curved plastic panel (11) to form the curved glazing (1).

3. A method to manufacture a curved glazing (1) according to claim 1 or 2, characterized in that at least one interlayer (13) provided inbetween the glass sheet (12) and the plastic panel (11).

4. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that at least one glass sheet (12) is provided on each of the main surfaces of the plastic panel (11).

5. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the plastic panel (11) has a thickness in the range of 1 mm to 50 mm.

6. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the glass sheets (12) have a thickness lower than 1.5 mm, preferably lower than 1.1 mm, even more preferably lower than 0.9 mm.

7. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the thickness of the plastic panel (11) is equal or greater than the twice of the total thickness of the glass sheets (12), preferably equal or greater than three times of the total thickness of the glass sheets (12).

8. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the material of the plastic panel (11) is a polycarbonate based material.

9. A method to manufacture a curved glazing (1) according to claims 3 to 8, characterized in that the interlayers (13) are chosen amongst PVB, EVA, TPU, TPE, OCA, adhesives or PU based material.

10. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the plastic panel (11) has a light transmission of higher than 50%.

11. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the plastic panel (11) further comprises light diffusing elements.

12. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the area of the main surfaces of the plastic panel (11) is larger than the area of the glass sheets (12).

13. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the method further comprises a step of injecting at least one thermoplastic component (14) on at least a part of the periphery of the curved glazing (1).

14. A method to manufacture a curved glazing (1) according to any preceding claims, characterized in that the method further comprises a step of applying at least one thermal management coating on the glass sheets (12) before or after the assembly of the curved glazing (1).1715. A vehicle glazing (1) comprising a plastic panel (11) and two glass sheets (12), manufactured by the method of claim 1 to 14.

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