TITLE: Process and Apparatus for Decorative Glaze Printing of Solid Surface Products

SPECIFICATION

Field:

This invention relates to the field of printing decorative glaze formulations onto custom, high density, engineered, solid surface products, including countertops, table tops, benchtops, worktops, back splashes, sinks, vanity tops, shower flooring, flooring and other architectural surfaces such as vertical wall surfaces and decorative panels. More specifically the invention relates to a method of, and apparatus for application of glaze formulations onto the horizontal surfaces and vertical edges of custom-shaped, compound (3-D), fused high density, silicate mineral-containing, engineered solid surface products (FHD-S) that are then fired to produce unique decorative and utilitarian surfaces in a wide range of designs, colors and textures, including artistic, one-of-a-kind works. The inventive apparatus and method permits ₍ unitary designs to be continuous on all surfaces, that is, wrapped around compound 3-D surfaces to produce an authentic perspective of the design.

Background:

A recently developed class of surface materials comprise high density, silicate mineral-containing engineered products (herein “engineered” materials) that have improved properties as compared to natural stone materials and polymer-matrix slab materials. The stone materials include natural materials, such as: marble, granite, soap stone, igneous lava-type materials such as basalt, and metamorphic materials such as slate. Natural granite is in wide spread use because of its hardness, beautiful range of colors and natural patterns of its crystalline components and veining. It can also be diamond polished to a high gloss. However, granite is porous, prone to staining and molds and bacteria can find harbor in the discontinuities of the crystalline boundaries. Thus, a granite surface requires a sealant, preferably one having biocidal properties, which must be periodically re-applied. In addition, granite is provided in 2-D slabs which must be cut, fitted and glued or grouted together in order to form compound, 3-D shapes, such as a kitchen or bathroom countertop having a backsplash or/and a vertically extended front edge. The resulting compound product has grout or glue lines that require cleaning and restoration maintenance and are prone to separation over time.

Polymer matrix-bonded materials, by way of example only, include such well-known brands as: Corian (DuPont), Caesarstone (Caesarstone, Sdot-Yam, IL; Caesarstone Inti, US), Silestone (Cosentino, SA), Swanstone (Swan Co.), Staron (Samsung), Zodiaq (DuPont), Avonite (Aristech), Hanex (Hanwha Living & Creative, KR), Hi-Macs/Viatera (LG Hausys, KR). These products comprise stone powder and/or granules retained in a plastic matrix, such as acrylic, polyester or polyurethane polymer, co-polymer or ter-polymer. Most include binders and colorants to provide monolithic color, so that cut edges have the same color throughout.

However, polymer matrix materials, while non-porous, are highly UV sensitive, resulting in their change of color and degrading over time when exposed to light. Thus, such materials are not recommended or warranted for exterior use, such as out-door cook-tops, tables, benches or vertical architectural panels. They also have a relatively low cut and abrasion resistance, and some may discolor when a hot pan is placed on the surface, that is, they exhibit “bum” marks. While abrasion marks may be buffed out, cuts and gouges have to be filled with acrylic or polyester epoxy resins, then polished, but color matching ranges from problematic to impossible.

Ceramic tiles and slab sanitary ware ceramics are prone to cracking and fracture in use, e.g., when implements are dropped onto them. In addition, tiles are not considered self- supporting over large areas, and require backing board, mastic and grouted seams when used on both horizontal and vertical surfaces.

In contrast the class of fused silicate mineral-containing engineered solid surface materials involved herein, which do not include polymer binders or matrixes, are unitary slab materials that are self-supporting over large areas and are typically installed without backing mastic and grouted seams. When installed on vertical surfaces, they can be retained in place by use of mechanical fasteners suitably engaging the slabs and the wall surface elements. Depending on size, they may also be installed on vertical surfaces using mastic, a silicone-based adhesive, or silica gel, the latter used in high temperature environments such as in the case of a fireplace surround.

Non-exhaustive or inclusive examples of fused silicate mineral-containing engineered materials include Dekton (Cosentino, SA), Lapitec (Breton, FR) and Neolith and Laminam (sintered stone). Both are produced in a high temperature process. Lapitec is an inorganic sand- based material, sintered at about 1200°C to produce “full body” (understood to mean monolithic) slabs. Dekton is a proprietary product involving densification of quartz (Silicate mineral) particulates followed by semi-sintering with small amounts of flux to produce a fine grained monolithic slab product. Since the silicate mineral silicate mineral in these materials is fired, they are termed “fused”. In these materials, there is a limited color palette based on inorganic colorant components mixed into the materials prior to firing resulting in uniform color throughout the thickness of the material. These materials may be used out of doors, or in interiors exposed to sunlight.

Another current trend is to apply surface decals onto of large tiles, slab surfaces of vitreous ceramic and fused silicate mineral-containing engineered slabs, after which the decals are fired. Current decals comprise images that mimic natural stone surfaces, typically marble, or granite. However, the decal is a thin surface feature only, which is revealed when an edge is cut, as it must be for installation. Thus, the fired surface design does not flow over onto an exposed edge, such as the front edge of a kitchen counter, or the revealed edge for an under-mounted sink. Although it is possible to fold a decal over the edge, the result is a face design on an edge, which results in an unnatural image on the edge.

Accordingly, there is an unmet need in this art for a true design break-out for permanent fused silicate mineral-containing engineered solid surface materials that are universal in use, both indoors and outdoors, has high strength, is non-porous, optionally may not require sealing, has design elements that flow over corners including complex shapes, does not require on-the job cutting for fitting sinks or faucets, can be custom pre-designed and shop prefabricated for on site installation with minimal cutting or fitting at installation, is capable of being highly and artistically decorated, including accurate wrapping of design features over compound surfaces, which decoration can be achieved during fabrication to result in unique, one of a kind for each job, architectural and design elements, and is competitively priced with currently available solid surface materials.

THE INVENTION

Summary:

The invention comprises an apparatus and method for digital printing on-demand and firing of custom glaze composition designs applied to custom pre-cut solid surface fused, high density, silicate mineral-containing engineered products (FHD-S). The inventive apparatus and method includes “glaze-jet” custom digital on-demand printing by means of a 6-axis print head that permits continuous printing of a pre-selected and digitally-sizable design to accurately fit both horizontal and vertical surfaces, so that the resulting designs are natural in that the edge designs are orthogonal analogs of the surface design.

Thus, in accord with the inventive method, the vertical surfaces are depicted as true representations of the horizontal surface projected into an orthogonal dimension rather than being an unnatural wrap of the horizontal surface onto a vertical surface. In natural stone, the veining showing on a horizontal surface, for example, is an oblique exposure of the vein material, rather than being normal to the surface. Thus, the veining seen in a vertical section view, such as at an edge or back splash, does not follow the same line as on the surface. Rather, it is inclined in accord with the oblique angle of intersection with the horizontal surface. The inventive method digitally defines the different surfaces: both horizontal and vertical, the latter including both surfaces extending below and above the horizontal surface. Thus, taking a sink or kitchen counter for example, the sides (or end edges), front edge and sink are represented as continuations of oblique veining, for example, below the horizontal surface, and the rear back splash continuations of veining above the plane of the horizontal surface.

The inventive process includes computerized preparation of a horizontal surface design, by way of example, a digital CAD-cam artistic representation of a highly veined stone. The design dimensions are digitally fluid; that is, they may be enlarged or reduced as needed, or the aspect ratio changed. The surface design is digitally overlain onto the outline of a custom dimensioned and cut silicate mineral-containing engineered slab. The outline may be as-drawn (e.g., as engineering or architectural layout drawings) or constructed from measurements provided from a pattern database. In the alternative, a digital photograph of an as-cut slab may be used. The digital surface design is adjusted in an image program to fit the slab outline. The veins are identified and each is tagged with a preselected degree of oblique intersection. A projection program extends the respective veins at the margins of the horizontal surface onto adjacent vertical surfaces into the corresponding vertical dimensions, e.g., downwardly for a front edge ogee, one or more side end ogees, compound surfaces such as a sink, or upwardly for vertical surfaces such as a back splash. The design is thus ready for computer controlled on- demand printing.

While this design process is described by way of example with respect to veining, it should be understood that the same process is applied to intra-vein spaces and inclusions (such as representation of unique crystals) and to provide subtle color gradients, intricate veining or other artistic images. In addition a wide range of colors may be applied to selected areas of the design to produce the final look of the piece. The resulting design is rendered, preferably in 3-D, so that it may be displayed for rotation to be viewed from various angles, as desired. It should be understood that different veins of the same or different color may be inclined at differing angles so that they approach, intersect or diverge from each other when projected onto the vertical surfaces for realistic representation.

For complex surface shapes, e.g., a highly curved edge or other type of curved transition, the curve transition area details may be simplified, e. g., 10 - 30% fewer pixels, without un natural loss of continuity of the design.

Once the design has been approved by the customer, contractor, architect, etc., the design is loaded into a printer controller as an identified product design. The inventive high accuracy printer apparatus comprises a planar work table, e.g., a rectangular table having a length and a width, onto which is loaded the precut work piece. Where the printing includes vertical and horizontal printing, the work piece is raised above the work table with suitable furniture that retains the work piece in sure position against movement, a suitable height above the table for access of a printer head to the exposed vertical surfaces. The print head is mounted on a support means, e.g., a rolling gantry that spans the width of the work table, or on a beam that spans the width of the table, with each end of the beam including drive wheels that travel on raised tracks, one track positioned on each side of the longitudinal dimensional length of the work table. The head support gantry/beam travels in the X, longitudinal direction along the length of the work table. The print head is mounted on a vertical elevator assembly which in turn is mounted on the beam to move laterally in the Y direction across the width of the table. The vertical elevator assembly permits the print head to move in the vertical Z direction. In addition, the print head is mounted via an indexable, powered gimbal assembly to the vertical elevator assembly. This provides the added 4 ^th - 6 ^th axes of movement, left-right and up-down, and of rotation on a printer head axis.

In another example, the print head may be gimbal-mounted on a support means robotic arm of length sufficient to reach the full dimensions of a work piece, including access to opposite side vertical surfaces. The print head-mounting support systems described just above enable high accuracy printing of complex images in glaze frit type inks, with the result that upon firing, realistic or/and highly artistic glaze surfaces are produced.

The silicate mineral-containing engineered base slabs are on the order of 6’wide x 12’ long, i.e., 2 m wide x 4m long. Since the print heads are smaller in printing width than the width of the slab, the heads being typically 2” to 12” wide, i.e., 5 - 30 cm wide, multiple swaths of printing with digital interlace or “stitching” along the edges of each swath for unbroken continuity of image is required. Specialty print heads may be constructed to provide one-swath, full width printing. However, for certain complex surface shapes, smaller heads will allow better printer access, e.g., a recessed sink or bowl for example, a head smaller in width than the bowl will permit access to the bottom of the bowl for effective printing. Thus, different printing swath width heads can be used for the different surfaces: horizontal, vertical and compound curved surfaces. In addition, in one embodiment of the apparatus of this invention, print heads having compound shapes may be employed to print, for example, a head having up or/and down-turned end portions to print vertical surfaces while the main body of the print head uses downwardly directed jets to print the horizontal surface. Thus in one swath the front vertical ogee edge, main flat horizontal surface and rear vertical back splash may be printed.

The print heads may include sensors to detect the edge(s) of previously printed swaths, plus computer controlled actuators in the print heads to adjust their positioning for seamless laydown of glaze swaths without overlap or gaps. Distance to the surface sensors may also be incorporated in the heads to permit proper head positioning for the ceramic frit ink laydown and for following of the head over compound surfaces via the 6-axis controller of the printing machine.

In still another embodiment, multiple print heads, 1, 2, 3, . . .n, may be arrayed in a side by side or staggered relationship on the elevator gimbal assembly of the printer. This establishes precise orientation of a second swath printed by head #2 with respect to a first swath printed by head #1. The individual nozzles of each print head are addressable and glaze frit ink feed to them is controlled by the printer controller. Thus, for example, in a multiple-print head printer, where the head #2 is oriented orthogonal, to print a vertical surface, to head #1 to print a horizontal surface, the nozzles are fed and actuate only when the head #2 encounters, that is, senses, the vertical surface it is to print. Thus, when the multi-head printer starts the last, rearmost horizontal swath adjacent a rear backsplash surface, only then is head #2 also actuated to simultaneously print the vertical surface of the backsplash, while head #1 prints the last horizontal swath. Being mounted on the same gimbal assembly, there is no positioning errors, and no swath gaps or overlaps.

In another embodiment, the print heads are disposed arrayed in tandem, in which a forward print head prints one color or design, and the following another color or design. For example, the forward head prints background color(s) or design, and the trailing head prints other details. Thus, the forward head may print the background of a stone surface, and the trailing head prints veining.

Exemplary print heads that can be used are: Kerajet, such as a model S7 for digital printing of ceramic pigments; or Xaar liquid jet-type ceramic printer heads, such as a Xaar model 2001 +GS12C, such type heads being pizeo-electric-driven, print-on-demand, droplet feed print heads, offered in resolutions from 180 to 1200 dpi with drop sizes ranging from 10 - 200 picoliters/drop. Still other suitable print heads are the NEra models D and V of DipTech, using 12 ink channels for photo-realistic image printing up to 1410 dpi with variable drop size and employing continuous ink recirculation to and from the reservoirs to the print head nozzles for consistent high speed printing.

Multiple different glaze frits may be simultaneously printed by feeding individual nozzles of the print head via a plurality of frit feed lines (also called channels), selected for the colors, fineness of detail and effects, such as gloss, matte, eggshell, lustre, metallic, flame, and the like, required for the identified design pattern. For fine design, a 720 -1600 dpi resolution is preferred. The laydown, i.e., amount of glaze applied, typically ranges from 20g/m ² to 170g/m ² and depends on well-understood factors, including viscosity, use of flocculants or deflocculants, thickeners, frit grain size and printer head orifice size, rate of deposition, and speed of movement of print head. Since the print head is computer controlled, the amount of a pre- selected glaze deposited at a particular place can be varied. In addition, overprinting is possible, e.g., a clear overglaze may be applied after a first laydown followed by optional drying, or, for example, a Zinc Silicate frit overprinted to provide crystallinity in the fired glaze.

An important aspect of the instant invention is multi-layer printing which can also be referred-to as “sedimentary printing”. In the inventive process, multi-pass laydown of plural layers of colored frit and clear nano-frit essentially recreates the sedimentary or igneous processes by which natural stone materials are created. The base Silicate mineral -containing engineered material permits developing a substantial surface layer (1/8” - 1/4” thickness) of printed glaze having a compatible coefficient of thermal expansion. That is, the multi-layer printed glaze fits the body without issues. As a result, the extra thick multi-layer results in the visual depth that is seen in natural stone.

The frits should be selected for compatibility; that is, they should all melt within a preselected range so that the as-being-fired glaze viscosity of the different gaze colors is closely the same. One skilled in the glazing art will recognize that firing temperature should be controlled for the desired end-effect. Thus, for example, an orange peel texture is achievable at a given temperature, while raising the peak firing point to a higher temperature permits the glazes to flow together for a smooth finish. A wide range of suitable frits are commercially available from Ferro, Pemco and Mason.

The support means-mounted high-accuracy print heads of this invention are driven via a processor-based control system communicably coupled to a computer-readable storage device wherein a database of printable images is stored for call-up and execution on demand. The control system further comprises internally at least one processor circuit, communicably linked to one or more storage devices such as disk drive or optical or magnetic storage devices, memory, input and output devices, and preferably, a network interface for external communications. Stored in memory are the operating system and a plurality of applications, e.g., image resizing, stretching, coloring, rendering, orthogonal conversion of horizontal surface features to vertical continuations, overlaying, and the like, one or more databases, browser(s) for accessing and navigating the Internet via the network interface. In addition the memory stores the operating BIOS, RAM and ROM for full functionality. Input devices include a keyboard, mouse and scanner to input images; sensors from the machine tool status or operational functions, e.g., print head positioning in multi-axes, print speed, laydown rate, scanning of the work surface contours, swath paths, etc. The sensors are mounted in association with the print head or the head support means and function to provide information on the positional status or operational functions of said support means or/and head, including functions selected from among at least one of print head positioning in multi-axes, print speed, glaze laydown rate, scanning of contours and boundaries of said work piece surface, and print swaths.

Optionally a haptic screen and microphone may be included as input devices for touch and audio, e.g., voice activation, of screen displays, conversion to text, to perform commands, etc. Additionally the control system includes physical output devices, such as printers, monitor and video screen displays, haptic outputs, audio outputs and illuminators of the work piece. The output devices for printing include: ceramic frit ink feeders to, and ejectors of, the print heads, the functioning of which are individually controlled by the application algorithms. The control system communicates to the machine drivers, such as the gantry, cross-beam, elevator, gimbal, robotic arm, etc., and to the print head(s) via the network interface. These elements of a control system are well understood to those in the relevant machine control art, and need not be described in further detail.

An IR heater, alone or with an air blower may be mounted in tandem with the print head, or on an auxiliary head on the printer machine to assist in rapidly drying or curing the glaze frit inks. This heater may be selectively energized via the controller, e.g., last pass heating so that there is good interlacing of adjacent print swaths in advance of drying, or after the last print layer is applied so there is good wet or damp bonding between layers before drying. Conversely, where depth in the fired glaze is developed by sedimentary printing, each layer may be dried as it is being printed by the heater.

The inventive process steps proceed as follows, taking by way of example a custom kitchen counter top: In a first embodiment, a standard silicate mineral-containing engineered 6’ x 12’ (2 m x 4 m) slab is positioned on the printer bed. Where one or more vertical side or end edges are to be printed, the slab is elevated sufficiently with furniture to permit the print head to access the sides or ends. A design is selected and displayed in the control system computer display, then overlain on a template of the slab, being sized to fit. Glaze frit ink print parameters, e.g., colors, veining, laydown, finish (e.g., gloss, crackle, orange peel, metallic, flamed, and the like), are selected and input, including edge dimensions to be printed. The glaze frit ink printing is started and controlled through completion. The printed glaze frit ink may be dried as it is being printed by IR lamps or/and blown air drying, or the printed slab transferred to a special drier muffle. After drying the printed glaze frit ink, the printed slab is transferred to a kiln for firing in a preselected firing schedule. After firing, the slab is let cool, then withdrawn from the kiln, inspected for quality, and if inspection is satisfactory, the glazed slab sent to a fabrication facility for cutting to dimensions for a preselected job. After cutting the cut edges may be polished as needed and the finished, dimensioned slab if forwarded to a job site for custom installation. In a second embodiment, precise measurements are taken at a job site or drawn per specifications for the installation. For niche fitting and mitered comer joins, e.g., for a countertop that includes one or more sections that is/are orthogonal to a main run, approximately lmm is deducted to produce an “adjusted pattern”. Where the installation is against a wall, the wall (longitudinal) edge should be gauged (profiled in plan view) to determine if it is straight, and if not, the raw slab is cut to match the gauged profile. The adjusted pattern is laid out on a raw, that is, not glaze-printed and glaze-fired slab and the slab is cut at a fabrication facility, e.g., by means of a diamond saw or water jet cutter. The pattern cutting includes holes for the sink and the faucet, and any other purpose-dedicated holes, notches, relieved-areas and unique custom profiles. Where the fitting to an appliance requires precision clearance, the hole is enlarged from 1- 2mm. Thus, where an under-mount sink is to be installed, the hole is cut approximately 2mm wider in both dimensions, width and length (depth, as distinguished from thickness).

The pre-glazed cut raw slab(s) may be taken to the job site for checking, or the as-cut dimensions checked against the pattern. The customer, contractor, architect, interior designer or artist selects a glaze or stain color, glaze type (oxidized or reduced), lustre (e.g., matte, gloss, crystalline, metallic), artistic design, texture, pattern, or machined surface finish. As used herein the reference to “stain(s)” means the colorants used in the glaze composition to impart color. The selected glaze(s) or stain(s) are printed and dried as described above onto the upper surface and exposed edges (work or visible surface) of the pre-cut slab(s), which is/are then fired in an appropriate firing schedule. The glaze/stain is selected to fit the slab body so that the glaze/stain is subject to from zero to a suitably small amount of compression. The slab/body material has essentially zero shrinkage upon glaze/stain firing, so that the pre-cut dimensions are retained. Where a back-splash piece of the type that rests on the slab is used, the area of the slab under the back-splash bottom edge need not, but may be, glazed or stained. However, the printer system described herein can print integrated back-splash vertical surfaces, as well as integrated sinks. Thus, in accord with the inventive process the glaze color and design will continue over the counter top front edge, rear back-splash, integral sink(s) etc., such as edge chamfers, a bull nose, an ogee, double ogee, or some custom profile.

The finished, glazed silicate mineral-containing piece is transported to the work-site for installation. Because of the body stability upon glaze firing, the pre-glazing-cut-to-dimension is well within tolerances for the installation and fitting of appropriate appliances, in the case of the exemplary countertop, the sink(s), faucets, and sprayers. The result is a custom countertop that does not require any substantial cut-to-fit-work on the job-site.

Accordingly, the invention opens the door for an incredible range of artistic design and creativity that can be applied to large solid surfaces on a piece-by-piece, truly custom print/glaze-on-demand basis, to satisfy the requirements of discerning home owners and commercial establishments requiring architecturally and artistically unique surfaces. The glazed large solid surfaces of this invention do not have the disadvantageous distractions of grid-works of grout lines evident when using small glazed tiles, nor the upkeep of the grout, yet has all the advantages of the highest quality porcelain. In addition, unlike mass-produced surfaces wherein the customer has only a limited range of selected colors and granulation types, the inventive process and glazed products are one of a kind, unique and bring an artistic dimension into the field of large architectural solid surfaces.

Brief Description of the Drawings:

The invention is described in more detail with reference to the drawings and photographic illustrations, in which:

Fig. 1 is a flow sheet outlining the steps of the inventive process;

Fig. 2 an exemplary schematic diagram of the control system components of the inventive apparatus;

Figs. 3 A - C illustrate an exemplary, robotic ar -type 6 - axis printer system of the present invention, in which Fig. 3A shows the print head positioned to print the top lip of a vanity back splash; Fig 3B shows the print head positioned to print the bowl of a vanity sink; and Fig. 3C shows the print head printing the vertical edge of a countertop.

Detailed Description of The Invention:

The following detailed description illustrates the invention by way of example, not by way of limitation of the scope, equivalents or principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention.

All publications, patents and applications cited in this specification are herein incorporated by reference as if each individual publication, patent or application had been expressly stated to be incorporated by reference.

Fig. 1 shows the steps of the invention in flow-sheet format. The inventive process 10 starts at 12 with selection of the silicate mineral-containing engineered slab or fused 3-D construct 14. In the next phase, site or plan-based dimensions are developed at 16 for a unique custom job. The gauged, fired slab is then cut at 18 to specification dimensions at in a fabrication shop, including cut-outs and dimensional allowances for exposed glazed surfaces, e.g., outer exposed edges, and cut-out edges for under-mount sinks and the like. Optionally surface and edge texturing is applied at 20. As required, edges are profiled at 22, e.g., the front edge of a countertop is ogee profiled. The resulting raw piece 24 is then jigged into the printer assembly, including being raised on furniture to permit the articulated print head to access vertical edges.

A 3-D model of the raw piece 24 is derived, e.g., via CAD-CAM software in the computer control system and displayed on a monitor screen at 26. Optionally, the printer assembly has the capability to scan the jigged raw piece 24, and the 3-D model derived from the scan at 28. From the controller database, an image, e.g., a custom design, is selected to be printed and this image is positioned via print-simulation software over the 3-D model, at 30. The controller, employing a printing algorithm generates printing head paths, also called “swathes”, 32, to be executed by the print driver operating the printer assembly during controlled printing 34 in the printer assembly in accord with the custom design 30. Depending on the image selected, multi-layer printing 36 may be effected, and as required by the ink frit properties, optional IR/UV radiation exposure 38 may be used to cure each successive layer of ink between passes. The glaze-printed piece is fired at 40 pursuant to a firing schedule appropriate for the silicate mineral-containing engineered body and glaze composition. Upon cool-down, the finished piece is quality-control checked and sent to inventory; this ends the production process, 42.

Referring to Fig. 2, the high-accuracy print heads of this invention (see Figs. 3A - 3C) are driven via a processor-based control system 100 communicably coupled to at least one computer-readable storage device wherein a database of printable images is stored for call-up and execution on demand. The control system 100 further comprises internally at least one processor circuit 102, communicably linked 104 to one or more storage devices, such as disk drive or optical or magnetic storage devices 106, memory 108, input 110 and output 112 devices, and preferably, a network interface 114, for external communications. Optionally a removable disk drive or memory stick drive 116 may be provided. Stored in memory 108 are the operating system and a plurality of applications, e.g., image resizing, stretching, coloring, overlaying, etc., one or more databases, browser(s) for accessing and navigating the Internet via the network interface. In addition the memory stores the operating BIOS, RAM and ROM for full functionality. Input devices 110 include a keyboard, mouse and scanner to input images; sensors from the machine tool status or operational functions, e.g., print head positioning in multi-axes, print speed, laydown rate, scanning of the work surface contours, swath paths, etc. Optionally a haptic screen and microphone may be included as input devices for touch and audio, e.g., voice activation, of screen displays, conversion to text, to perform commands, etc. Additionally the control system includes physical output devices 112, such as printers, monitor and video screen displays, haptic outputs, audio outputs and illuminators of the work piece. The output devices for printing include: ceramic frit ink feeders to, and ejectors of, the print heads 118, the functioning of which are individually controlled by the application algorithms. The control system communicates to the printer assembly 120, such as the gantry, cross-beam, elevator, gimbal, robotic arm, etc., and to the print head(s) via the network interface 114. Optionally, offsite cloud or other storage may be employed, 122. These elements of a control system are well understood to those in the relevant machine control art, and need not be described in further detail.

Referring to Figs. 3A - 3B, an exemplary printer assembly 200 is illustrated , in this case a multi-axis robotic arm 202 having gimbal-mounted on its outboard end a 3 -Axis print head assembly 204. Due to the scale limitations the ink reservoirs and multiple color lines feeding the print heads in the head assembly 204 are not shown. Positioned in the printer assembly table 206 is a fired silicate mineral-containing engineered piece 208, mounted on suitable furniture pieces 210, 212. The fired Silicate mineral-containing engineered piece shown in Fig. 3A and 3B is a lavatory top including a horizontal surface 214, a back splash 216, a bowl 218 and a front vertical lip 220. The piece shown in Fig. 3C is a countertop 222, having side vertical edges, 224 and 226. Shown in Fig. 3A, the print head assembly has been rotated by the controller system 100 operating the robotic arm 202 to print the top edge of the back splash 216. In Fig. 3B, the print head 204 is rotated and the outboard end of the robot arm 202 has been extended to print a swathe across the top horizontal surface 214 and over the joining edge to the bowl and into the bowl area. Fig. 3C shows the print head 204 printing an ogee side edge 226 of a countertop section. The sensors assist in ranging the print nozzles to the surfaces to be printed so that the distance remains constant across the 3-D surface contours of the piece being printed.

The examples given above show that the inventive fired monolithic silicate mineral- containing engineered slab that has been glazed have a uniquely custom look, texture and color palette. The glaze top surface layer is on the order of between from about 5mm to about 3mm in thickness, and is acid resistant, abrasion and impact resistant, and color-fast, permitting external uses in areas exposed to solar radiation without fading or degradation. The glaze layer provides and added layer of weather and use resistance to the base slab material.

It is also important to note that the unique glaze texture and artistic look of the inventive surface slabs may be applied and fired to be continuous from a top surface over the front facing edge of a horizontal slab. This is in contrast to a slab having a pressed top surface, as a result of which the design and texture does not continue over the front edge, essentially distracting from or ruining the effect of surface relief produced by platen presses. Likewise, the application of a decal to the upper surface of a slab would not result in an over-the-edge design and texture continuity. In platen press surface relief or decal applications, the front edge would be a saw cut, requiring polishing, but having a different, non-continuous look, essentially an unfinished front edge. The brilliance, depth and unique look of the surface cannot be achieved in a monolithic slab alone, not only top surface but also exposed edges, nor the continuity of color, design, texture and depth.

INDUSTRIAL APPLICABILITY:

It is clear that the inventive process and products of this application has wide applicability to the construction industry, namely to bringing custom design, including a full range of artistic and design creativity to large FHD-S slab surfaces as well as 3-D products. The method clearly permits production of unique, one of a kind surface pieces, such as countertops, vanities, kitchen sinks, tables, wall surfaces and the like on an economical basis, as the silicate mineral -containing engineered FHD-S pieces are uniquely custom decorated and fired after being cut to measure, rather than the customer (homeowner, business owner, architect, interior designer, etc.) being limited to a narrow range of granular surface “looks” of engineered polymer surface materials. The range of applications, to the exterior rather than being confined to interior sun-shaded areas, is much broadened, and the inventive products have no less than the stability, stain resistance, impermeability and scratch resistance utility of expensive stone products. Thus, the inventive process and products have the clear potential of becoming adopted as the new standard for custom home, office, hotel and commercial space surfaces.

It should be understood that various modifications within the scope of this invention can be made by one of ordinary skill in the art without departing from the spirit thereof and without undue experimentation. For example, the glazed surfaces can have a wide range of artistic designs to yet retain the functionalities disclosed herein. Likewise, the inventive process and apparatus is widely applicable to silicate mineral-containing fired products, including high silicate mineral materials such as Neso (ortho) silicates, Sorosilicates, Cyclosilicates, Inosilicates (such as Wollastonite), Phyllosilicates, Tectosilicates (such as Quartz, Si02), ceramic materials, sanitary ware, glass materials, engineered quartz materials and other high density materials of the types referenced herein. This invention is therefore to be defined by the scope of the appended claims as broadly as the prior art will permit, and in view of the specification if need be, including a full range of current and future equivalents thereof.