FIELD

This invention relates to a laminated glass and method of fabrication thereof.

BACKGROUND

Laminated glass typically comprises two clear sheets of glass joined together by an interlayer provided between the two clear sheets. The interlayer may comprise a number of sub-layers making up a thickness of the interlayer. The interlayer holds the two clear sheets together when the glass is shattered, thereby preventing the glass from breaking up into sharp pieces that may cause harm. Laminated glass is thus considered safer and stronger than unlaminated glass sheets. In some embodiments, one or both sheets of glass may be replaced with impact resistant polycarbonate for even greater strength and safety.

While it is possible to fabricate decorative laminated glass by providing one or both of the two clear sheets with an externally textured surface, this results in the exterior surface of the laminated glass not being smooth. Such exteriorly textured glass is more costly to clean and maintain due to its textured surface.

Attempts to provide the textured effect on inward facing surfaces of the clear sheets in laminated glass so as to retain a smooth, easily maintained outer surface have not been successful. This is because during fabrication of the laminated glass, the interlayer fills in all gaps in the textured surface so that the resulting laminated glass appears to be flat without any texture.

It is therefore desirable to be able to provide and fabricate laminated glass that can have at least a textured or other three-dimensional decorative effect while retaining exterior surface smoothness of the laminated glass for cost effective and easy maintenance.

SUMMARY

According to a first aspect, there is provided a laminated glass comprising: a special layer provided between a first interlayer and a second interlayer; the first interlayer, the special layer, and the second interlayer provided between a first clear sheet and a second clear sheet; wherein the special layer comprises at least one layer of at least one additively manufactured structure, the special layer providing at least one of: a functional effect and a decorative effect to the laminated glass.

The special layer may comprise a plurality of layers of additively manufactured structures alternated with a number of intermediate layers, each intermediate layer provided between the number of layers of structures.

The special layer may comprise two layers of additively manufactured structures and one intermediate layer provided between the two layers of structures.

The special layer may comprise three layers of additively manufactured structures alternated with two intermediate layers.

The special layer may be configured to be veined and translucent to give an impression of the laminated glass being a slab of natural stone.

Thickness of each intermediate layer may be greater than a sum of a first depth and a second depth, the first depth being depth of a deepest void present on a surface of a first layer of at least one additively manufactured structure facing a first side of the intermediate layer, and the second depth being depth of a deepest void present on a surface of a second layer of at least one additively manufactured structure facing a second side of the intermediate layer.

Each layer of additively manufactured structures may have lower transparency than each intermediate layer.

The at least one structure may comprise at least one tube configured to channel light within the laminated glass.

The at least one structure may comprise a three-dimensionally printed solar panel.

The at least one structure may comprise a thermochromic additive. The laminated glass may further comprise a second special layer provided between a third interlayer and a fourth interlayer; the third interlayer, the second special layer, and the fourth interlayer provided between the second clear sheet and a third clear sheet; wherein the further special layer may comprise at least one layer of at least one additively manufactured structure, the further special layer providing at least one of: a functional effect and a decorative effect to the laminated glass.

The laminated glass may further comprise a third interlayer provided between the second clear sheet and a third clear sheet.

The third clear sheet may comprise one of: glass, acrylic, polycarbonate, polystyrene, polypropylene, polyethylene terephthalate, amorphous polyethylene terephthalate, and polyethylene terephthalate glycol.

The first clear sheet may comprise one of: glass, acrylic, polycarbonate, polystyrene, polypropylene, polyethylene terephthalate, amorphous polyethylene terephthalate, and polyethylene terephthalate glycol.

The second clear sheet may comprise one of: glass, acrylic, polycarbonate, polystyrene, polypropylene, polyethylene terephthalate, amorphous polyethylene terephthalate, and polyethylene terephthalate glycol.

Thickness of the first interlayer may be greater than depth of a deepest void present on a surface of the special layer facing the first interlayer.

Thickness of the second interlayer may be greater than depth of a deepest void present on a surface of the special layer facing the second interlayer.

The at least one additively manufactured structure may have a lower transparency than the first clear sheet, the second clear sheet, the first interlayer and the second interlayer.

According to a second aspect, there is provided a method of fabricating a laminated glass, the method comprising the steps of: (a) forming at least one structure by additive manufacturing to fabricate a special layer comprising at least one layer of the at least one structure;

(b) assembling, in given order, a first clear sheet, a first interlayer, the special layer, a second interlayer, and a second clear sheet to form a layered assembly;

(c) de-airing the layered assembly,

(d) heating the de-aired layered assembly at an appropriate temperature for a predetermined duration to bond the first interlayer with the first clear sheet and the special layer and to bond the second interlayer with the special layer and the second clear sheet to form the laminated glass.

The method may further comprise applying pressure to the layered assembly in step (d).

According to a third aspect, there is provided a method of fabricating a laminated glass, the method comprising the steps of:

(a) forming at least one structure by additive manufacturing to fabricate a special layer comprising at least one layer of the at least one structure;

(b) assembling, in given order, a first clear sheet, the special layer, and a second clear sheet to form a layered assembly with a first space between the first clear sheet and the special layer and a second space between the second clear sheet and the special layer;

(c) fully filling the first space and the second space with a laminating liquid to form a filled layered assembly,

(d) curing the laminating liquid in the filled layered assembly, thereby forming and bonding the first interlayer with the first clear sheet and the special layer and forming and bonding the second interlayer with the special layer and the second clear sheet to form the laminated glass.

Step (d) may comprise heating the filled layered assembly at an appropriate temperature for a predetermined duration. Alternatively, step (d) may comprise irradiating the filled layered assembly with ultraviolet light for a predetermined duration.

The method may further comprise applying pressure to the layered assembly after step (c).

For all aspects, the at least one additively manufactured structure may have a three- dimensional form and may be at least sometimes visible in the laminated glass.

BRIEF DESCRIPTION OF FIGURES

In order that the invention may be fully understood and readily put into practical effect, there shall now be described by way of non-limitative example only exemplary embodiments of the present invention, the description being with reference to the accompanying illustrative drawings.

FIG. 1 is a schematic cross-sectional illustration of a first exemplary embodiment of a laminated glass.

FIG. 2 is a schematic cross-sectional illustration of a second exemplary embodiment of a laminated glass.

FIG. 3 is a schematic front view illustration of the laminated glass of FIG. 2.

FIG. 4 is a schematic cross-sectional illustration of a third exemplary embodiment of a laminated glass.

FIG. 5 is a schematic cross-sectional illustration of a fourth exemplary embodiment of a laminated glass.

FIG. 6 is a schematic cross-sectional illustration of a fifth exemplary embodiment of a laminated glass.

FIG. 7(a) is a schematic front view illustration of an exemplary embodiment of a switchable laminated glass in a first state.

FIG. 7(b) is a schematic front view illustration of an exemplary embodiment of a switchable laminated glass in a second state.

FIG. 7(c) is a schematic front view illustration of an exemplary embodiment of a switchable laminated glass in a third state.

FIG. 8 is a flow chart of a first exemplary method of fabrication of the laminated glass of

FIG. 1.

FIG. 9 is a flow chart of a second exemplary method of fabrication of the laminated glass of

FIG. 1.

DETAILED DESCRIPTION

Exemplary embodiments of a laminated glass 100 and a method 200 of its fabrication will be described below with reference to FIGS. 1 to 9. The same reference numerals are used across the figures to denote the same or similar parts. As shown in FIG. 1 (not drawn to scale), the laminated glass 100 comprises at least a first clear sheet 11, a first interlayer 21, a special layer 30, a second interlayer 22, and a second clear sheet 12. The special layer 30 is provided between the first interlayer 21 and the second interlayer 22. The first interlayer 21, the special layer 30, and the second interlayer 22 are provided between the first clear sheet 11 and the second clear sheet 12. The special layer 30 is configured to provide a functional and/or decorative effect to the laminated glass 100, as will be described in greater detail below.

The laminated glass 100 may comprise more than two clear sheets 11, 12, as will be described in greater detail below. The clear sheets 11, 22 may be the same or different from each other, and may each comprise a clear sheet of untreated glass, annealed glass, heat- strengthened glass, tempered glass, polycarbonate, acrylic, polystyrene, polypropylene, polyethylene terephthalate, amorphous polyethylene terephthalate, polyethylene terephthalate glycol and so on, such as may be suitable for use as a window, wall, or door, for example. By the term “clear sheet”, this is meant to include sheets that are transparent or translucent, coloured or colourless. Each clear sheet may be 1.8 mm to 2.3 mm thick, or any other desired thickness. Notably, each clear sheet may be flat or curved with any desired curvature profile so that the laminated glass 100 may be flat or curved according to the curvature profile.

The laminated glass 100 may comprise more than one special layer 30. Each special layer 30 comprises at least one layer 40 of at least one structure 44 having a three-dimensional form that is at least sometimes visible in the laminated glass 100. The structure 44 is preferably additively manufactured, i.e., formed by additive manufacturing, as will be described in greater detail below, and may be transparent, translucent, or opaque, and may be coloured or colourless. For example, the special layer 30 may comprise a sheet 40 of a three-dimensionally (3D)-printed lattice structure 44. Other examples additively manufactured structure 44 are described below. Where a recyclable polymeric resin is used to additively manufacture the structure 44, the laminated glass 100 can be configured to be recyclable. The special layer 30 may have any desired thickness, for example ranging from 0.5 mm to 10 mm in some embodiments. The laminated glass 100 is preferably exteriorly smooth while the at least one additively manufactured structure 44 is at least sometimes, if not always, visible as a three-dimensional form within the laminated glass 100. This may be achieved by forming the structure 44 using a material of lower transparency than the clear sheets 11, 12 and interlayers 21, 23, or configuring the structure 44 to have colour and/or surface texture or configuring the structure 44 to have switchable or selectable opacity or colour, for example. This ensures that the structure 44 can be visible after all voids in the structure 44 have been filled in by the interlayers 11, 12 during fabrication of the laminated glass 100, as will be described in greater detail below.

The laminated glass 100 may comprise more than two interlayers 11, 12, as will be described in greater detail below. Each interlayer 21, 22 may be made of one or more known interlayer materials used to fabricate laminated glass, such as polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or thermoplastic polyurethane (TPU), for example, and have a thickness of 0.38 mm, 0.76 mm, 1.14 mm, 1.54 mm, 1.9 mm, 2.28 mm, or any other desired thickness. Each interlayer 21, 22 is pliable and able to follow surface contours of the clear sheets 11, 12 and the special layer 30 when assembled together to form a layered assembly during fabrication of the laminated glass 100. Optionally, each interlayer 11, 12 may comprise one or more sub-layers (not shown) that make up a desired thickness of each interlayer 11, 12, which need not be the same for all the interlayers 11, 12 in the laminated glass 100. In exemplary embodiments, each sub-layer may be 0.38 mm thick, so that each interlayer 21, 22 may be 0.38 mm thick, or have a thickness that is a multiple of 0.38 mm. Alternatively, each interlayer 21, 22 may comprise a cured, laminating liquid (such as a liquid resin) that is poured into spaces provided between the clear sheets 11, 12 and the special layer 30, as will be described in greater detail below.

Notably, the thickness of each interlayer 21, 22 should be greater than a depth of a deepest void present on a surface of the special layer 30 facing each interlayer 21, 22 respectively. This ensures that each interlayer 21, 22 fully infiltrates all voids present on the adjacent surface of the special layer 30 and bonds the special layer 30 with the respective adjacent clear sheet 11, 12. For example, if a surface of the special layer 30 facing the first interlayer 21 has voids that are a maximum of 1.0 mm deep when formed during additive manufacturing of the structure 44 of the special layer 30, the first interlayer 21 should accordingly have a thickness of 1.14 mm, for example, to fully infiltrate the 1.0 mm deep voids on the special layer 30 and also bond the special layer 30 to the first clear sheet 11. Thickness of the interlayers 21, 22 also depends on architectural or glass safety level specification requirements.

A common example of additive manufacturing by which the at least one additively manufactured structure 44 of the special layer 30 is formed is 3D printing; however, other methods of additive manufacturing are available. Rapid prototyping or rapid manufacturing are also terms which may be used to describe additive manufacturing processes.

As used herein, “additive manufacturing” refers generally to manufacturing processes wherein successive layers of material(s) are provided on each other to “build-up” layer-by- layer or “additively fabricate”, a three-dimensional component. This is compared to some subtractive manufacturing methods (such as milling or drilling), wherein material is successively removed to fabricate the part. The successive layers in additive manufacturing generally fuse together to form a monolithic component which may have a variety of integral sub-components. In particular, the additive manufacturing process may allow an example of the disclosure to be integrally formed and include a variety of features not possible when using prior manufacturing methods.

Additive manufacturing methods described herein enable manufacture to any suitable size and shape with various features which may not have been possible using prior manufacturing methods. Additive manufacturing can create complex geometries without the use of any sort of tools, moulds or fixtures, and with little or no waste material. Instead of machining components from solid billets of plastic or metal, much of which is cut away and discarded, the only material used in additive manufacturing is what is required to shape the structure 44.

Suitable additive manufacturing techniques in accordance with the present disclosure include, for example, Fused Deposition Modeling (FDM), Selective Laser Sintering (SLS), 3D printing such as by inkjets and laserjets, Sterolithography (SLA), Direct Selective Laser Sintering (DSLS), Electron Beam Sintering (EBS), Electron Beam Melting (EBM), Laser Engineered Net Shaping (LENS), Electron Beam Additive Manufacturing (EBAM), Laser Net Shape Manufacturing (LNSM), Direct Metal Deposition (DMD), Digital Light Processing (DLP), Continuous Digital Light Processing (CDLP), Direct Selective Laser Melting (DSLM), Selective Laser Melting (SLM), Direct Metal Laser Melting (DMLM), Direct Metal Laser Sintering (DMLS), Material Jetting (MJ), NanoParticle Jetting (NPJ), Drop On Demand (DOD), Binder Jetting (BJ), Multi Jet Fusion (MJF), Laminated Object Manufacturing (LOM) and other known processes.

The additive manufacturing processes described herein may be used for forming the structure 44 using any suitable material. For example, the material may be plastic, metal, composite, concrete, ceramic, polymer, epoxy, photopolymer resin, or any other suitable material that may be in solid, liquid, powder, sheet material, wire, or any other suitable form or combinations thereof. More specifically, according to exemplary embodiments of the present subject matter, the additively manufactured structure 44 described herein may be formed in part, in whole, or in some combination of materials including but not limited to transparent or translucent polymeric resin. These materials are examples of materials suitable for use in additive manufacturing processes which may be suitable for the fabrication of examples of the structure 44 described herein.

As noted above, the additive manufacturing process disclosed herein allows a single structure 44 to be formed from multiple materials. Thus, the examples described herein may be formed from any suitable mixtures of the above materials. For example, the structure 44 may include multiple layers, segments, or parts that are formed using different materials, processes, and/or on different additive manufacturing machines. In this manner, the structure 44 may be constructed which have different materials and material properties for meeting the demands of any particular application. In addition, although the structures 44 described herein are constructed entirely by additive manufacturing processes, it should be appreciated that in alternate embodiments, all or a portion of these structures 44 may be formed via casting, machining, and/or any other suitable manufacturing process. Indeed, any suitable combination of materials and manufacturing methods may be used to form these components.

Additive manufacturing processes typically fabricate components based on three- dimensional (3D) information, for example a three-dimensional computer model (or design file), of the structure 44. Accordingly, examples described herein not only include structures 44 as described herein, but also methods of manufacturing such products or components via additive manufacturing and computer software, firmware or hardware for controlling the manufacture of such structures 44 via additive manufacturing.

The design of one or more parts of the structure 44 may be represented digitally in the form of a design file. A design file, or computer aided design (CAD) file, is a configuration file that encodes one or more of the surface or volumetric configuration of the shape of the structure 44. That is, a design file represents the geometrical arrangement or shape of the structure 44.

Design files can take any now known or later developed file format. For example, design files may be in the Stereolithography or “Standard Tessellation Language” (.stl) format which was created for stereolithography CAD programs of 3D Systems, or the Additive Manufacturing File (.amf) format, which is an American Society of Mechanical Engineers (ASME) standard that is an extensible markup-language (XML) based format designed to allow any CAD software to describe the shape and composition of any three-dimensional object to be fabricated on any additive manufacturing printer.

Further examples of design file formats include AutoCAD (.dwg) files, Blender (.blend) files, Parasolid (.x_t) files, 3D Manufacturing Format (.3mf) files, Autodesk (3ds) files, Collada (.dae) files and Wavefront (.obj) files, although many other file formats exist.

Design files can be produced using modelling (e.g. CAD modelling) software and/or through scanning the surface of a product to measure the surface configuration of the structure 44.

Once obtained, a design file may be converted into a set of computer executable instructions that, once executed by a processer, cause the processor to control an additive manufacturing apparatus to produce the structure 44 according to the geometrical arrangement specified in the design file. The conversion may convert the design file into slices or layers that are to be formed sequentially by the additive manufacturing apparatus. The instructions (otherwise known as geometric code or “G-code”) may be calibrated to the specific additive manufacturing apparatus and may specify the precise location and amount of material that is to be formed at each stage in the manufacturing process. As discussed above, the formation may be through deposition, through sintering, or through any other form of additive manufacturing method.

The code or instructions may be translated between different formats, converted into a set of data signals and transmitted, received as a set of data signals and converted to code, stored, etc., as necessary. The instructions may be an input to the additive manufacturing system and may come from a part designer, an intellectual property (IP) provider, a design company, the operator or owner of the additive manufacturing system, or from other sources. An additive manufacturing system may execute the instructions to fabricate the structure 44 using any of the technologies or methods disclosed herein.

Design files or computer executable instructions may be stored in a (transitory or non- transitory) computer readable storage medium (e.g., memory, storage system, etc.) storing code, or computer readable instructions, representative of the structure 44 to be produced. As noted, the code or computer readable instructions defining the structure 44 that can be used to physically generate the object, upon execution of the code or instructions by an additive manufacturing system. For example, the instructions may include a precisely defined 3D model of the structure 44 and can be generated from any of a large variety of well-known computer aided design (CAD) software systems such as AutoCAD®, TurboCAD®, DesignCAD 3D Max, etc. Alternatively, a model or prototype of the structure 44 may be scanned to determine the three-dimensional information of the structure 44.

Accordingly, by controlling an additive manufacturing apparatus according to the computer executable instructions, the additive manufacturing apparatus can be instructed to print out one or more parts of the structure 44. These can be printed either in assembled or unassembled form. For instance, different sections of the structure 44 may be printed separately (as a kit of unassembled parts) and then subsequently assembled. Alternatively, the different parts may be printed in assembled form.

In light of the above, embodiments include methods of manufacture via additive manufacturing. This includes the steps of obtaining a design file representing the structure 44 and instructing an additive manufacturing apparatus to manufacture the structure 44 in assembled or unassembled form according to the design file. The additive manufacturing apparatus may include a processor that is configured to automatically convert the design file into computer executable instructions for controlling the manufacture of the structure. In these embodiments, the design file itself can automatically cause the production of the structure 44 once input into the additive manufacturing device. Accordingly, in this embodiment, the design file itself may be considered computer executable instructions that cause the additive manufacturing apparatus to manufacture the structure 44. Alternatively, the design file may be converted into instructions by an external computing system, with the resulting computer executable instructions being provided to the additive manufacturing device.

Given the above, the design and manufacture of implementations of the subject matter and the operations described in this specification can be realized using digital electronic circuitry, or in computer software, firmware, or hardware, including the structures 44 disclosed in this specification and their structural equivalents, or in combinations of one or more of them. For instance, hardware may include processors, microprocessors, electronic circuitry, electronic components, integrated circuits, etc. Implementations of the subject matter described in this specification can be realized using one or more computer programs, i.e., one or more modules of computer program instructions, encoded on computer storage medium for execution by, or to control the operation of, data processing apparatus. Alternatively, or in addition, the program instructions can be encoded on an artificially generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium can also be, or be included in, one or more separate physical components or media (e.g., multiple CDs, disks, or other storage devices).

Although additive manufacturing technology is described herein as enabling fabrication of complex objects by building objects point-by-point, layer-by-layer, typically in a vertical direction, other methods of fabrication are possible and within the scope of the present subject matter. For example, although the discussion herein refers to the addition of material to form successive layers, one skilled in the art will appreciate that the method 200 and structures 44 disclosed herein may be practiced with any additive manufacturing technique or other manufacturing technology.

In some embodiments of the laminated glass 100, the special layer 30 may comprise a number of layers 40 of additively manufactured structures 44 alternated with a number of intermediate layers 35 each provided between the number of layers 40 of structures 44, as shown in FIGS. 2 and 3 (not drawn to scale). The number of intermediate layers 35 serve to embed and support the structures 44 in the laminated glass 100, and also to make up a desired thickness of the laminated glass 100 together with the first interlayer 21 and the second interlayer 22. In such embodiments, the number of layers 40 of structures 44 may be two or more, and the number of intermediate layers 35 may be one or more, wherein the number of intermediate layers is one less than the number of layers of structures. In some embodiments, the intermediate layers 35 may be made of the same material as the first and second interlayers 11, 12. Referring to FIG. 2, thickness of each intermediate layer 35 is greater than a sum of a first depth and a second depth, the first depth being depth of a deepest void present on a surface of a first layer of at least one additively manufactured structure facing a first side of the intermediate layer, and the second depth being depth of a deepest void present on a surface of a second layer of at least one additively manufactured structure facing a second side of the intermediate layer.

In some embodiments, the special layer 30 may comprise two layers 40 of additively manufactured structures 44 and one intermediate layer 35 provided between the two layers 40 of structures 44, wherein the two layers 40 of structures 44 are each adjacent the first interlayer 21 and the second interlayer 22 respectively, as shown in FIG. 2. In other embodiments, the special layer 30 may comprise three structures 44 formed by additive manufacturing alternated with two intermediate layers 35 such that two of the structures 44 are each adjacent the first interlayer 21 and the second interlayer 22 respectively, and the third structure 44 is provided between the two intermediate layers 35, as shown in FIG. 3. Appreciably, forming the additively manufactured structure 44 allows a myriad of configurations of the at least one structure 44 to be achieved in the special layer 30. In this way, the special layer 30 can be specifically configured to provide an extensive range of creative 3D decorative and/or functional effects to the laminated glass 100 for architectural and other uses, such as in door panels, fencing panels, wall panels, windows, lighting covers, for example.

For example, the structure 44 may comprise at least a tube or a plurality of tubes through which light may be channelled to allow the laminated glass 100 to serve as a light fixture, as shown in FIG. 2. In this example, the one or more tubes may be positioned in the laminated glass 100 to allow products that are placed behind the laminated glass to be highlighted, as shown in FIG. 3. In another example, the channelled light may comprise a sanitizing ultraviolet light such as UVC, so that the laminated glass 100 can be provided in areas where disinfection by UVC may be desirable, such as in lifts or elevators, bathrooms, healthcare facilities and so on.

In other embodiments, the additively manufactured structure or structures 44 can be configured to encapsulate polymer-dispersed liquid crystals therein and attached via electrodes to a power supply to allow the laminated glass 100 to function as a switchable glass to transition from being opaque to being transparent, by varying a voltage applied to the electrodes. Where the special layer 30 in the laminated glass 100 comprises more than one layer 40-1, 40-2 of structures 44 configured to provide a switchable glass function, such structures 44 can be provided at different areas of each layer 40-1, 40-2, as shown in FIG. 7(a)-(c). By controlling the voltage applied to each layer 40-1, 40-2, the structures 44 in the specific areas of each layer 40-1, 40-2 can be selectably rendered opaque or transparent. In this way, different visible states of the laminated glass 100 can be achieved that appear different from each other. The additively manufactured structures 44 are thus configured to be at least sometimes visible in the laminated glass 100. For example, FIG. 7(a) to 7(c) shows a laminated glass 100 having a special layer 30 comprising two layers 40-1, 40-2 of additively manufactured structures 44 provided at different areas of each layer 40-1, 40-2. In FIG. 7(a), only the structures 44 in the specific area of the first layer 40-1 are rendered opaque (as indicated by the hatched lines). In FIG. 7(b), only the structures 44 in the specific area of the second layer 40-2 are rendered opaque. In FIG. 7(c), both the structures 44 in the first layer 40-1 and the second layer 40-2 are rendered opaque. Appreciably, the specific areas where opacity- switching structures 44 are provided may be of any desired shape, and the level of opacity may also be varied by adjusting the applied voltage accordingly.

In another example (not shown), the structure 44 may comprise a 3D printed solar panel. The structure 44 may also be configured to provide a decorative 3D effect in the laminated glass 100. In some embodiments (not shown), the special layer 30 may further comprise at least one digitally printed film to further enhance the decorative effect of the laminated glass 100. In some embodiments (not shown), the structure 44 may be formed from in 3D from a resin that contains one or more appropriate additives such as thermochromic inks or dyes that change colour with temperature.

Alternating three layers of structures 44 with two intermediate layers 35 as shown in FIG. 4 allows the special layer 30 to be configured to provide a veined, translucent decorative effect to the laminated glass 100 to give an impression of the laminated glass 100 being a slab of natural stone, such as onyx, instead of glass. Such laminated glass 100 can serve as a decorative backlit wall and can also be further configured to provide ambient lighting by the inclusion of lighting-channelling tube structures 44 in the special layer 30.

In embodiments where the special layer 30 includes multiple layers 40 of additively manufactured structures 44 alternated with one or more intermediate layers 35, thickness of each intermediate layer 35 is greater than a sum of a depth of a deepest void present on a layer of additively manufactured structures on a first side of the intermediate layer and a depth of a deepest void present on a layer of additively manufactured structures on a second side of the intermediate layer. This allows the intermediate layer 35 to fully infiltrate voids that are on the layers 40 of additively manufactured structures 44 on each side of the intermediate layer 35 and to bond the layers 40 together.

In some embodiments, the laminated glass 100 may comprise more than two clear sheets 11, 12. Providing more clear sheets in the laminated glass 100 strengthens the laminated glass 100. For example, the laminated glass 100 can comprise one or more clear sheets of polycarbonate, in addition to or alternatively to clear sheets of glass, to provide the laminated glass 100 with some level of bullet resistance. In an exemplary embodiment as shown in FIG. 5, the laminated glass 100 may comprise three clear sheets 11, 12, 13. In embodiments of the laminated glass 100 comprising more than two clear sheets, optionally, a second special layer 31 may be provided between a third interlayer 23 and a fourth interlayer 24, wherein the third interlayer 23, the second special layer 31 and the fourth interlayer 24 are provided between the second clear sheet 12 and a third clear sheet 13. The further special layer 31 may have any configuration as described above for the special layer 30. For example, the further special layer 31 may comprise one layer 40 of at least one additively manufactured structure 44, or multiple layers 40 of additively manufactured structures 44 alternated with intermediate layers 35 (not shown). The optional inclusion of additional special layers 30 allows for a greater variety of decorative and functional designs to be achieved and provided in the laminated glass 100.

Alternatively, only a third interlayer 23 may be provided between the second clear sheet 12 and the third clear sheet 13, as shown in FIG. 6.

Appreciably, other embodiments (not shown) of the laminated glass 100 can include four or more clear sheets and interlayers between clear sheets, and optionally further include additional special layers provided between the interlayers between the clear sheets.

In an exemplary method 200 of fabricating the above-described laminated glass 100, as shown in FIG. 8, the special layer 30 is first fabricated by forming the at least one structure 44 by additive manufacturing 202. The first clear sheet 11, the first interlayer 21, the special layer 30, the second interlayer 22, and the second clear sheet 12 are then assembled in the order given 204 to form a layered assembly. Using a laminating machine (not shown, for example, a SAGERTEC® Alam-PVB Series glass laminating machine), the layered assembly is de-aired 206 to remove air from the layered assembly. The de-aired layered assembly is heated at an appropriate temperature (such as 100 °C, for example) for a predetermined duration 208 in the laminating machine to bond the first interlayer 21 with the first clear sheet 11 and the special layer 30 and to bond the second interlayer 22 with the special layer 30 and the second clear sheet 12 to form the laminated glass 100. The laminated glass 100 is cooled and removed from the laminating machine. Depending on the configuration of the laminated glass 100 to be formed, pressure may or may not be applied to the layered assembly during heating of the de-aired layered assembly to bond the different layers of the laminated glass 100 together.

Where the laminated glass 100 comprises more than one special layer, more than three interlayers and more than two clear sheets, in the method 200 of fabricating the laminated glass 100, the multiple special layers are first fabricated by additive manufacturing 202, followed by assembling all layers of the laminated glass 100 in the desired order 204 to form the layered assembly. The layered assembly is then de-aired 206 and heated at an appropriate temperature for a predetermined duration 208 as described above.

In another exemplary method 200 of fabricating the above-described laminated glass 100, as shown in FIG. 9, the special layer 30 is first fabricated by forming the at least one structure 44 by additive manufacturing 202. The first clear sheet 11, the special layer 30, and the second clear sheet 12 are then assembled in the order given 204 to form a layered assembly with a first space provided between the first clear sheet 11 and the special layer 30, and a second space provided between the special layer 30 and the second clear sheet 12. The first and second interlayers 21, 22 are then formed in the first and second spaces respectively by first fully filling the first and second spaces with a laminating liquid, such as a liquid resin, to form a filled layered assembly 206, followed by curing the laminating liquid by heating at an appropriate temperature or irradiating with ultraviolet light the filled layered assembly for a predetermined duration 208. This forms and bonds the first interlayer 21 with the first clear sheet 11 and the special layer 30, and also forms and bonds the second interlayer 22 with the special layer 30 and the second clear sheet 12, thereby form the laminated glass 100. Depending on the configuration of the laminated glass 100 to be formed, pressure may or may not be applied to the layered assembly after filling of the first and second spaces and before curing of the laminating liquid.

The above described laminated glass 100 allows decorative textural effects provided by the special layer 30 to remain visible while allowing the laminated glass 100 to retain its smooth exterior surface, thereby reducing cost of cleaning and maintenance compared to the cost for conventional exteriorly textured glass. Using laminated glass fabrication methods, visibly- textured but exteriorly- smooth designer glass can be made that reduces carbon dioxide emission compared to conventional methods of forming exteriorly textured glass. Not only can decorative textural effects be provided, the laminated glass 100 also allows uniquely designed, three-dimensional, functional and/or decorative structures 44 to be provided and protected within the thickness of the laminated glass 100, while requiring only the same maintenance as conventional laminated glass. Transparent, translucent, opaque and/or reflective colouring may also be applied in the additively manufactured structures 44 to provide both decorative and functional effects to the above-described laminated glass 100.

Whilst there has been described in the foregoing description exemplary embodiments of the present invention, it will be understood by those skilled in the technology concerned that many variations and combination in details of design, construction and/or operation may be made without departing from the present invention. For example, the interlayers may each comprise any other appropriate material besides PVB, EVA or TPU mentioned above. The structure or structures may comprise any desired design, configuration and material other than the embodiments described above and depicted in the figures, and may be made by other methods besides additive manufacturing. Various embodiments of the laminated glass may be fabricated by any other process besides using the exemplary embodiments of the method of fabrication described above and depicted in the figures.