PROCESS AND APPARATUS FOR MANUFACTURING OF AN ETCHED

METAL SUBSTRATE

TECHNICAL FIELD

The present invention relates to a process for manufacturing of an etched metal substrate, and an apparatus for carrying out the process or part diereof. More particularly, but not exclusively it relates to an industrial process and apparatus for large scale production of etched metal substrate.

BACKGROUND OF THE INVENTION

Presently the etching of metal substrates such as zinc, copper, aluminium, steel and alloys and laminates thereof, is known for use in the manufacture of etched interior or exterior facade panels, laminates and other construction or building coverings, as well as in the automotive and aerospace industries, and other general consumer applications.

Metals and their alloys are typically used to produce facade panels for interior or exterior of buildings. Flat metal plates are typically provided in a pre-anodised form.

Selective etching of a metal substrate is usually carried out by applying a mask to the plate, and then applying a corrosive agent to the masked plate to corrode the metal that has not been masked. Masks are typically applied by screen printing or painting a mask layer onto the metal plate. The mask is then allowed to dry, or cure, depending on the nature of the mask layer. Screen printing of masks is generally expensive and time consuming. Tearing of screens is a problem that causes delays and typically requires the carrying of replacement screens, which can be expensive.

The use of screen printing also has issues with quality and process

reproducibility, as it involves pushing highly viscous liquid through a fine mesh screen.

A corrosive etching chemical is then applied to the whole plate. The corrosive chemical causes corrosion of the metal on those parts of the plate that are not protected by the mask. The corrosive chemical is then washed off, and the mask removed. Partial masking may also be used to obtain special effects.

The mask is typically removed by the application of another chemical or solvent that dissolves or delaminates the mask material, or can be removed physically by means of mechanical or thermal processes. In some cases, such as where aluminium is used, aluminium plate is then subject to another anodisation process, to prevent degradation of the metal when subjected to the elements, or to provide a third aesthetic effect or colour.

Etching is a time consuming and expensive process, and the nature of the masking step and mask removal step makes it inherently suited to batch processing. Batch processing requires the supply of individual metal sheets, which are then each subjected to each of the steps described above in the etching process, allowing for the requisite amount of time for each step.

However, the large scale etching of metal plates by batch processing means that large amounts of stock must be kept, and large amounts of space are required to store the batches during their various stages of processing.

For this reason, it is desirable to increase the speed of processing of large scale etching processes.

In this specification, where reference has been made to external sources of information, including patent specifications and other documents, this is generally for the purpose of providing a context for discussing the features of the present invention. Unless stated otherwise, reference to such sources of information is not to be construed, in any jurisdiction, as an admission that such sources of information are prior art or form part of the common general knowledge in the art.

For the purposes of this specification, when a process is described involving a number of steps, then the steps shall not be presumed to be in chronological order unless there is no other logical manner of carrying out the steps.

For the purposes of this specification, when a process or production line is described as being "continuous", this shall be interpreted to mean that the process or production line is moving continuously, or in small discrete movements, or a to a feed that is unbroken, at least for the part of the process or production line referred to as being continuous, and shall be opposed to the concept of batch processing or batch-type production lines.

For the purposes of this specification, the term "etching" is defined to mean the broad term for a process whereby a substrate, being preferably metal, is selectively or partially masked and an etching agent applied to the substrate to selectively corrode features onto the substrate area that is not masked, to provide an at least aesthetic or functional effect, and may or may not include mask application, subsequent mask removal, rinsing, passivation and/ or coating of the substrate, and the corresponding terms "etch" or "etched" are to be construed in a similar fashion.

Preferably, the term "digital printing" relates to a printing process controlled by digital instructions for guiding a controller to discretely deposit ink, and any references to a "digital printing process" or "digitally printing" shall be construed accordingly.

OBJECT OF THE INVENTION

It is an object of the present invention to provide an etching process, and an apparatus for carrying out the process or part thereof which overcomes or at least partially ameliorates some of die abovementioned disadvantages or which at least provides the public with a useful choice.

SUMMARY OF THE INVENTION

In a first aspect the present invention may be said to broadly consist in a process for manufacturing of an etched metal substrate, the process comprising:

^■ providing a coiled metal substrate;

^■ feeding said metal substrate from said coil in a continuous manner to an etching process line; and

^■ etching at least a part, or at least a part of a surface of, said metal

substrate on the etching process line.

Preferably, the metal substrate is a sheet of metal. More preferably, the metal substrate is a metal plate. Even more preferably, the metal substrate is a metal plate or metal sheet of uniform gauge (or thickness).

Preferably, the metal substrate is a metallised substrate. It should be appreciated the term "metal substrate" includes metals, metal alloys, and metalised substrates (using various techniques, including, but not limited to techniques such as vacuum deposition of metal or metal alloys).

Preferably, the metal substrate is an anodised metal substrate, or has been pre- anodised or anodised prior to being coiled.

Preferably, the etching process comprises the step of anodising the coiled metal substrate before etching.

Alternatively, the coiled metal substrate is a mill finished substrate.

Preferably, the etching step comprises the steps of: ^■ selectively depositing (or applying) a mask onto at least a part or at least a part of a surface of the continuously fed metal substrate, such that the metal substrate is provided with masked regions and/ or un-masked regions, and

■ subsequendy applying an etching agent to at least part of the substrate, or exposing at least part of the substrate to an etching agent, to selectively etch un-masked regions of the metal substrate.

Preferably, the mask is deposited (or applied) to the metal substrate, such that, an image is provided by the masked region, or un-masked region, or from the combination of the masked region and the un-masked region. More preferably, the image is one or more or a combination of images selected from a pattern library, preferably the pattern library comprises pre-determined images of: a lot number, a serial number, an identification number, a date or a time indication, a name, a logo, a trade mark, a make, a model, a manufacturer, a product identifier, an image, a photographic replication, a decoration, an artistic drawing, a design, a repeating pattern, a unique decorative identifier image.

Preferably, the etching process furdier comprises the step of:

^■ at least partially removing the deposited (or applied) mask or masked regions from the substrate.

Preferably, the step of removing the deposited (or applied) mask is carried out by performing one or more steps selected from:

" accelerating solid pellets of carbon dioxide towards the metal substrate to impinge upon the surface of the mask and/ or metal substrate; and/or

^■ subjecting the mask to ultrasound or ultrasonic treatment.

Preferably, the etching process further comprises one or more of the steps selected from:

^■ passivating the metal substrate; and/ or

^■ coating the metal substrate, or at least a part of the substrate or at least a part of a surface of the substrate, with a protective film or layer or surface or material.

Preferably, the step of deposition of the mask is by digital printing of the mask.

Preferably, the step of deposition of the mask includes one or more of the following metal substrate pre-treatment steps selected from: ^■ applying an adhesion enhancement agent to the metal substrate, or at least to a part or at least a part of a surface of the metal substrate; and

^■ heating the metal substrate.

Preferably, the adhesion enhancement agent promotes (or facilitates) adhesion of the mask being deposited (or applied) to the metal substrate, or at least the part or at least the part of the surface of the metal substrate applied with the adhesion enhancement agent.

Preferably, the etching process furtlier includes the step of rinsing the etching agent from the metal substrate.

Preferably, the etching process further comprises the step of rolling the etched continuous metal substrate into a coil.

Preferably, the etching process further comprises the step of rolling the continuous metal substrate into a coil at the end of the etching process line.

Alternately, the etching process comprises the step of cutting the continuous metal substrate into pre-determined lengths.

Preferably, the step of cutting the continuous metal substrate into lengths is by means of a flying shear.

Preferably, the step of cutting the continuous metal substrate into lengths is carried out:

■ after application of the mask, and/ or

^■ after application of the etching agent; and/or

" after passivation of the metal substrate; and/ or

^■ after coating of the metal substrate.

Alternatively, the etching process further comprises the step of cutting the continuous metal substrate into separate sheets.

Preferably, the mask deposition step comprises printing a mask onto the metal substrate fed continuously to the etching process line.

More preferably, the mask is printed on to the metal substrate via a continuous printing process.

Preferably, the continuous printing process is a digital printing process.

Preferably, the digital printing process prints the mask onto the continuous metal plate by an ink jet printing process. Preferably, the digital printing process prints the mask onto the continuous metal plate by a flatbed printer.

Preferably, the digital printing process prints the mask onto the continuous metal plate by an flatbed printer with an ultraviolet ink curing step.

Preferably, digital printing is performed by digital printing technologies, for example thermal transfer printing, ink jet printing, phase change or hot melt ink type printing. It will be appreciated thermal transfer printing is generally understood to involve a dry transfer printing process involving a combination of heat and pressure to bond a printable composition to a media. Where for example phase change, hot melt or ink jet type printers are to be used, the composition to be printed composition can be designed to have the appropriate properties to enable this process for printing on to the metal substrate.

Preferably, the digital printing process is controlled by a controller.

Preferably, the controller is guided by instructions for digitally accounting for continuous movement of the continuous metal substrate.

Preferably, the controller receives a signal indicative of the movement of the continuous metal substrate, and utilises this signal in the controlling of the digital printing process.

Preferably, the step of printing a mask onto the continuous metal substrate in a continuous printing process includes the step of:

^■ curing the printed mask.

Preferably, the step of curing the printed mask comprises at least one or more of the steps of

^■ exposing at least part of the printed mask to radiation;

■ heating at least part of the printed mask;

^■ exposing at least part of the printed mask to a chemical curing agent. Preferably, the radiation is ultra violet radiation.

Preferably, the step of printing the mask comprises a plurality of successive printing and curing steps.

Preferably, the step of printing the mask comprises a plurality of curing steps after each printing step.

Preferably, the step of printing the mask comprises a plurality' of successive printing and curing steps over a plurality of printing passes. Preferably, the etching step further comprises at least one or more selected from the steps of:

^■ heating at least part of the metal substrate; and

^■ coating at least part of the continuous metal substrate with an adhesion enhancement agent.

Preferably, the metal substrate is pre-heated before application of the adhesion enhancement agent.

Preferably, the adhesion enhancement agent is used to at least partially coat the continuous metal plate before printing on the metal substrate.

Preferably, the adhesion enhancement agent is a petroleum based solvent.

Preferably, the adhesion enhancement agent is a naptha petroleum based solvent.

Preferably, the adhesion enhancement agent is a naptha petroleum light aromatic solvent.

Preferably, the etching step comprises the step of:

^■ removing the mask.

Preferably, the step of removing the mask is by mechanical means (such as ultrasonic treatment, or impingement by solidified carbon dioxide pellets), or by non- solvent or non-chemical removal.

Preferably, the step of removing the mask includes one or more of the following steps:

^■ accelerating solid pellets of carbon dioxide towards the metal substrate to impinge upon the surface of the mask and/ or metal substrate; and

^■ subjecting the mask to one ultrasonic treatment.

Preferably, the ultrasonic treatment is of a frequency above 20kHz.

Preferably, the ultrasonic treatment is of a frequency above 150kHz. Preferably, the ultrasonic treatment is of a frequency between 150-400kHz. Preferably, the etching process includes one or more steps selected from

^■ coating the etched metal substrate with a protective coating; and ■ passivating the etched metal substrate in a passivating process.

Preferably, the coating is one or more selected from a

^■ clear coating;

^■ a semitransparent coating; ^■ a coloured coating.

Preferably, the metal substrate is one or more selected from

^■ zinc;

aluminium;

copper;

stainless steel;

steel (and coated steel such as galvanised steel);

titanium;

any other suitable material; and

■ any alloys of the above.

In another aspect, the invention may be said to consist broadly in a method of applying a mask to a metal substrate, said method comprising the steps of

^■ applying an adhesion enhancement agent to said metal substrate; and

^■ depositing (or applying) a mask on said metal substrate in a digital

printing process.

Preferably, the adhesion enhancement agent at least partially coats the metal substrate before printing on the metal substrate. More preferably, the adhesion

enhancement agent promotes adhesion of the digitally printed mask to the metal substrate.

Preferably, the method of applying the mask includes the step of

■ heating the metal substrate.

Preferably, the step of heating the metal substrate is carried out prior to application of the adhesion enhancement agent.

Preferably, the adhesion enhancement agent is a petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum light aromatic solvent.

Preferably, the method comprises the step of curing the digitally printed mask. Preferably, the step of curing the printed mask comprises at least one or more of the steps of:

^■ exposing at least part of the printed mask to radiation;

^■ heating at least part of the printed mask;

^■ exposing at least part of the printed mask to a chemical curing agent. Preferably, the heating of at least part of the printed mask is by blowing hot air on it.

Preferably, the radiation is ultra violet radiation.

Preferably, the step of printing the mask comprises a plurality of successive printing and curing steps.

Preferably, the printing process is carried out by printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by printing nozzles moving in a print nozzle direction.

Preferably, the successive printing and curing steps are each associated with one pass of the printer.

Preferably, the metal substrate is a continuously fed metal plate.

Alternately, the metal substrate is of a finite length.

Alternately, the metal substrate is a three dimensionally shaped metal substrate. Alternately, the metal substrate is a cast metal member.

Alternately, die metal substrate is a die cast metal member.

Alternately, the metal substrate is an extruded member.

Alternatively, die metal substrate is a flat sheet of metal plate that has been cut to a pre-determined length.

Preferably, the method comprises the step of providing the metal substrate.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 170 degrees to each other or less.

Preferably, the metal substrate comprises edges of planes extending at 190 degrees to each other or less. Preferably, the digital printing process is controlled by a controller.

Preferably the controller is guided by software instructions.

Preferably, the digital printing process is an ink jet printing process.

Preferably, the digital printing process is an ink jet printing process whereby ink for the mask is sprayed out of nozzles in a controlled fashion.

Preferably, the printing process is carried out by a printing head.

Preferably, the printing head comprises one or more printing nozzles.

Preferably, the printing head comprises one or more printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by a piinting head moving in a print head direction.

Preferably, ink is deposited by the printing nozzles in a print nozzle direction.

Preferably, the printing nozzles can deposit ink in a plurality of printing nozzle directions.

Preferably, the successive printing and curing steps are each associated with one or more passes of the printing head.

Preferably, the print head direction is at right angles to the direction of the feed of the continuously fed metal plate.

Preferably, the controller is guided by instructions for digitally accounting for the feed movement of the metal substrate, to control the printing process to print the mask.

Preferably, the controller is guided by instructions for digitally accounting for movement of the metal substrate from said continuous feed.

Preferably, the controller receives a signal indicative of the movement of the metal substrate, and utilises this signal in the controlling of the digital printing process.

Preferably, the method comprises the step of providing the metal substrate.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces. Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the step of printing on the metal substrate comprises printing substantially to the edges of said metal substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate.

Preferably, the instructions guide the controller as to the profile of the metal substrate.

Preferably, the instructions guide the controller as to the two dimensional profile of the metal substrate.

Preferably, the instructions guide the controller as to the three dimensional profile of the metal substrate.

Preferably, the step of printing comprises the step of printing via a plurality of printing heads to reduce the number of printing passes required by each of the printing heads to print said mask.

Preferably, the step of printing comprises the step of printing via a plurality of printing nozzles to reduce the number of printing passes required by said printing head to print said mask.

Preferably, the printing heads are reconfigurable to change the print nozzle direction of one or more of the associated printing nozzles.

Preferably, the printing heads are each movable in at least two two dimensions to follow the profile of the substrate.

Preferably, the printing heads are movable in at least three dimensions to follow the profile of the substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate when guiding movement of the print nozzles.

Preferably, the method comprises detecting the distance from the metal substrate to a datum at a plurality of locations on the metal substrate.

Preferably the method comprises the step of compiling a profile of the metal substrate from the detected distances at said plurality of locations.

Preferably, the method comprises the step of controlling the printing process according to the detected profile. Preferably, method comprises the step of controlling the movement of the printing head according to the detected profile.

Preferably, method comprises the step of controlling the operation of the printing head according to the detected profile.

Preferably, method comprises the step of controlling the printing nozzle direction according to the detected profile.

Preferably, the method comprises the step of controlling the print nozzles to remain within a printing distance of said metal substrate.

Preferably, the printing distance is between 0.1mm and 5 mm.

Preferably, the printing distance is between 0.5mm and 2 mm.

Preferably, the printing distance is about 1.2 mm.

In another aspect the invention may be said to broadly consist in a method of masking a metal substrate, comprising the steps of

^■ digitally printing a mask on said substrate in a digital printing process. Preferably, the method comprises the step of

^■ providing a metal substrate.

Preferably, the printing process is carried out by printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by printing nozzles moving in a print nozzle direction.

Preferably, the metal substrate is continuously fed by a conveyor system.

Alternately, die metal substrate is stationary during the step of printing. Alternately, the metal substrate is of a finite length.

Alternately, the metal substrate is a three dimensionally shaped metal substrate. Alternately, the metal substrate is a cast metal member.

Alternately, the metal substrate is a die cast metal member.

Alternately, the metal substrate is an extruded member.

Alternatively, the metal substrate is a flat sheet of metal plate that has been cut to a pre-determined length.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges. Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 170 degrees to each other or less.

Preferably, the metal substrate comprises edges of planes extending at 190 degrees to each other or less.

Preferably, the digital printing process is controlled by a controller.

Preferably the controller is guided by software instructions.

Preferably, the digital printing process is an ink jet printing process.

Preferably, the digital printing process is an ink jet printing process whereby ink suitable for masking is sprayed out of nozzles in a controlled fashion.

Preferably, the printing process is carried out by a printing head.

Preferably, the printing head comprises one or more printing nozzles.

Preferably, the printing head comprises one or more printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by a printing head moving in a print head direction.

Preferably, ink is deposited by the printing nozzles in a print nozzle direction.

Preferably, the printing nozzles can deposit ink in a plurality of printing nozzle directions.

Preferably, the method comprises the step of

^■ curing the digitally printed mask.

Preferably, the step of curing the printed mask comprises at least one or more of the steps of:

^■ exposing at least part of the printed mask to radiation;

^■ heating at least part of the printed mask;

^■ exposing at least part of the printed mask to a chemical curing agent. Preferably, the step of heating involves blowing hot air on the metal substrate. Preferably, the radiation is ultra violet radiation. Preferably, the step of printing the mask comprises a plurality of successive printing and curing steps.

Preferably, the successive printing and curing steps are each associated with one or more passes of the printing head.

Preferably, the printing head direction is at right angles to the direction of the feed of the continuously fed metal plate.

Preferably, the controller is guided by instructions for digitally accounting for the feed movement of the metal substrate, to control the printing process to print the mask.

Preferably, the controller is guided by instructions for digitally accounting for movement of the metal substrate from said continuous feed.

Preferably, the controller receives a signal indicative of the movement of the metal substrate, and utilises this signal in the controlling of the digital printing process.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 90 degrees to each other or less.

Preferably, the step of printing on the metal substrate comprises printing substantially to the edges of said metal substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate.

Preferably, the instructions guide the controller as to the profile of the metal substrate.

Preferably, the instructions guide the controller as to the two dimensional profile of the metal substrate. Preferably, the instructions guide the controller as to the three dimensional profile of the metal substrate.

Preferably, the step of printing comprises the step of

^■ printing via a plurality of printing heads to reduce the number of printing passes required by each of the printing heads to print said mask.

Preferably, the printing heads are reconfigurable to change the print nozzle direction of one or more of the associated printing nozzles.

Preferably, the printing heads are each movable in at least one dimension to follow the profile of the substrate.

Preferably, the printing heads are each movable in at least two dimensions to follow the profile of the substrate.

Preferably, the printing heads are movable in at least three dimensions to follow the profile of the substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate when guiding movement of the print nozzles.

Preferably, the method comprises detecting the distance from the metal substrate to a datum at a plurality of locations on the metal substrate.

Preferably the method comprises the step of

^■ compiling a profile of the metal substrate from the detected distances at said plurality of locations.

Preferably, the method comprises the step of

^■ controlling the printing process according to the detected profile.

Preferably, method comprises the step of

^■ controlling the movement of the printing head according to the detected profile.

Preferably, method comprises the step of

^■ controlling the operation of the printing head according to the detected profile.

Preferably, method comprises the step of

^■ controlling the printing nozzle direction according to the detected

profile.

Preferably, the method comprises the step of ^■ controlling the movement of the printing head to keep the print nozzles within a required printing distance of said metal substrate.

Preferably, the printing distance is between 0.1mm and 5 mm.

Preferably, the printing distance is between 0.5mm and 2 mm.

Preferably, the printing distance is about 1.2 mm.

Preferably, the step of providing a three dimensionally shaped metal substrate comprises delivering it on a movable conveyor system.

Preferably, the method comprises the step of

^■ controlling the movement of the conveyor system

Preferably, the method comprises the step of

^■ controlling d e movement of the conveyor system to facilitate the

printing process.

Preferably, the method comprises the step of

^■ accessing electronic patterns.

Preferably, the electronic patterns are stored on digital storage media.

Preferably, the method comprises the step of

^■ providing at least one or more electronic pattern over a network.

Preferably, the method comprises the step of

^■ manipulating the electronic patterns.

Preferably, the manipulation is by digital manipulation.

Preferably, the manipulation is account for the features of the three dimensional metal substrate, to present a substantially undisturbed pattern in at least one direction.

Preferably, the method comprises the step of

^■ controlling the movement of d e printing heads.

Preferably, the method comprises the step of

^■ controlling the movement of the printing nozzles.

Preferably, the method comprises the step of

^■ controlling the pivoting of the printing nozzles.

Preferably, the printing heads are movable by a moving mechanism. Preferably, the moving mechanism comprises a frame.

Preferably, the moving mechanism comprises at least one or more linear actuators. Pteferably, the linear actuators are linear motors, or electric motors driving a rack and pinion type mechanism.

Preferably, the linear actuators are one or more selected from

^■ hydraulically operated,

■ pneumatically operated, or

^■ electrically operated

Preferably, the step of controlling movement of the printing head(s) is by feedback control.

Preferably, the step of controlling movement of the printing head(s) comprises receiving a signal from a displacement measuring transducer.

Preferably, the displacement measuring transducer is one or more selected form

^■ one or more linear displacement transducers; and

^■ one or more angular displacement transducers.

Preferably, the step of controlling movement of the printing head(s) comprises controlling the movement of the printing head by means of feedback loops using signals received from the displacement measuring transducer.

In another aspect the invention may be said to broadly consist in an masking apparatus suitable for masking a metal substrate, comprising

^■ a masking arrangement comprising a movable printing head suitable for depositing ink on a three dimensional metal substrate to be masked;

^■ at least one controller for controlling

o the movement of the printing head, and

o the depositing of the ink from the printing head;

" digital storage media comprising instructions configured and adapted for:

o guiding the controller to move the printing head to vary the distance between the printer head and the metal substrate to account for changes in shape of the three dimensional metal substrate.

Preferably, the controller includes a processor.

Preferably, the controller comprises a transmitter for transmitting signals.

Preferably, the controller comprises a receiver for receiving signals.

Preferably, the masking arrangement is a printer.

Preferably, the masking apparatus comprises a plurality of printing heads. Preferably, the instructions are configured and adapted for

^■ guiding the controller to move the printing head in at least one dimensions for printing on said three dimensional metal substrate.

Preferably, the instructions are configured and adapted for

■ guiding the controller to move the printing head in at least three dimensions for printing on said three dimensional metal substrate.

Preferably, the masking apparatus comprises moving mechanism for moving said printing head.

Preferably, the moving mechanism are controllable by said controller. Preferably, the instructions are configured and adapted for

^■ guiding the controller to control movement of the moving mechanism. Preferably, the moving mechanism are linear movement actuators.

Preferably, the linear movement actuators operate by one or more selected from

^■ a hydraulic system;

■ electrical motors; and

^■ pneumatic motors.

Preferably, the apparatus comprises angular moving mechanism for changing the direction of printing of said printing head.

Preferably, the apparatus comprises angular moving mechanism for pivoting the printing head.

Preferably, the instructions are configured and adapted for

^■ guiding the controller to control movement of the angular moving

mechanism.

Preferably, the angular moving mechanism comprises electric motors d at pivot at least part of said printing head.

Preferably, the instructions are configured and adapted for

^■ guiding the controller to control the depositing of said ink onto said metal substrate.

Preferably, the printing head is configurable to deposit ink in at least two directions.

Preferably, the printing head is reconfigurable to deposit ink in at least two directions. Preferably, the printing head(s) each comprise at least one or more printing nozzles for depositing ink onto die substrate under pressure.

Preferably, the printing head(s) each comprise a plurality of printing nozzles for depositing ink onto the substrate under pressure.

Preferably, the printing nozzle(s) are movable in at least two dimensions.

Preferably, the printing nozzle is movable in at least three dimensions.

Preferably, the printing nozzle is pivotable about die printing head.

Preferably, the apparatus comprises at least one distance measurement means for generating a height signal indicative of the instructions are configured and adapted for distance of d e metal substrate to a datum.

Preferably, the apparatus comprises a plurality of distance measurement means.

Preferably, the instructions are configured and adapted for

^■ guiding the controller to receive d e height signal(s).

Preferably, the instructions are configured and adapted for

■ guiding the controller to calculate a profile signal indicative of the profile of the metal substrate.

Preferably, the instructions are configured and adapted for guiding the controller to

^■ accesses electronic patterns.

Preferably, the electronic patterns are stored on digital storage media.

Preferably, the instructions are configured and adapted for guiding the controller to

^■ provide at least one or more electronic pattern over a network. Preferably, the instructions are configured and adapted for guiding the controller to

^■ manipulate the electronic patterns.

Preferably, the manipulation is by digital manipulation.

Preferably, the manipulation is for purposes of accounting for the features of the three dimensional metal substrate, to present a substantially undisturbed pattern in at least one direction.

Preferably, the controller can use one or more selected from the height signal and the profile signal to control one or more selected from:

^■ the alignment of the printing head; the location of the printing head;

the angle of deposition of ink from said printing head; the movement of the printing head;

the rate of movement of the printing head;

the speed of movement of the printing head;

the rate of deposition of ink by said printing head;

the pattern to be deposited by said printing head.

Preferably, the instructions may be configured for

^■ guiding the controller to automatically modify the pattern to be deposited by the printing head according to the profile of the metal substrate.

Preferably, the automatic modification of the pattern to be deposited according to the profile of the metal substrate is in order to present a pattern that would have been presented if the metal substrate was not three dimensional.

Preferably, the instructions may be configured for

^■ guiding the controller to control the printing head to deposit two or more patterns on said substrate.

Preferably, the angle of inclination of the substrate determines which of the two or more patterns are to be deposited.

Preferably, the instructions are configured for

^■ receiving input from a user to select different patterns to be printed on different parts of said substrate, and guiding the controller in accordance with said user selection.

Preferably, the instructions are configured and adapted for guiding the controller to

^■ control the movement of the conveyor system

Preferably, instructions are configured and adapted for guiding the controller to

^■ control the movement of the conveyor system to facilitate the printing process.

Preferably, instructions are configured and adapted for guiding the controller to

^■ control the movement of the printing heads.

Preferably, instructions are configured and adapted for guiding the controller to

^■ control the movement of the printing nozzles. Preferably, instructions are configured and adapted for guiding the controller to

^■ control the pivoting of the printing nozzles.

Preferably, the printing heads are movable by a moving mechanism. Preferably, the moving mechanism comprises a frame.

Preferably, the moving mechanism comprises at least one or more linear actuators.

Preferably, the linear actuators are linear motors, or electric motors driving a rack and pinion ty e mechanism.

Preferably, the linear actuators are one or more selected from

■ hydraulically operated,

^■ pneumatically operated, or

^■ electrically operated

Preferably, the instructions are configured and adapted for guiding the controller to control movement of the printing head(s) by feedback control.

Preferably, instructions are configured and adapted for guiding the controller to control movement of the printing head(s) by receiving a signal from a displacement measuring transducer.

Preferably, the displacement measuring transducer is one or more selected form

^■ one or more linear displacement transducers; and

■ one or more angular displacement transducers.

Preferably, instructions are configured and adapted for guiding the controller to control movement of the printing head(s) by means of feedback loops using signals received from the displacement measuring transducer.

In another aspect the invention may be said to broadly consist in a method of masking a metal substrate for the purposes of etching it, said method comprising the step of

^■ digitally printing a mask on a continuously fed metal substrate. Preferably the digital printing of the mask is for purposes of etching the metal substrate.

Preferably, the method further comprises the step of curing the digitally printed mask.

Preferably, the step of curing the printed mask comprises at least one or more of the steps of ^■ exposing at least part of the printed mask to radiation;

^■ heating at least part of the printed mask;

^■ exposing at least part of the printed mask to a chemical curing agent. Preferably, the radiation is ultra violet radiation.

Preferably, the step of printing the mask comprises a plurality of successive printing and curing steps.

Preferably, the step of printing the mask comprises a plurality of curing steps after each printing step.

Alternatively, the successive printing and curing steps are each associated with one pass of the printer.

Preferably, the adhesion enhancement agent at least partially coats the continuous metal plate before printing on the continuous metal substrate.

Preferably, the adhesion enhancement agent is a petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum light aromatic solvent.

Preferably, the digital printing process is controlled by a controller.

Preferably, the metal substrate is a continuously fed metal plate. Preferably, the controller is guided by instructions for digitally accounting for continuous movement of the continuous metal plate.

Preferably, the controller receives a signal indicative of the movement of the continuous metal substrate, and utilises this signal in the controlling of the digital printing process.

In another aspect the invention may be said to broadly consist in method of etching a metal substrate comprising the steps of

^■ digitally printing a mask on a metal substrate, such that one or more masked regions and one or more un-masked regions are provided;

^■ subjecting (or exposing) the metal substrate to an etching agent or agents for etching the un-masked regions of the metal substrate.

Preferably, the metal substrate is fed into the digital printing process as a continuous feed. Alternatively, the metal substrate is fed into the digital printing process as a feed of individual flat metal substrate cut to pre-determined length.

The method may comprise the step of cutting the continuously fed metal substrate into lengths of cut metal substrate.

Preferably, the method further comprises the step of curing the digitally printed mask.

Preferably, the step of curing the printed mask comprises at least one or more of the steps of

^■ exposing at least part of the printed mask to radiation;

■ heating at least part of the printed mask;

^■ exposing at least part of the printed mask to a suitable curing chemical. Preferably, the radiation is ultra violet radiation.

Preferably, the step of printing the mask comprises a plurality of successive printing and curing steps.

Preferably, the adhesion enhancement agent at least partially coats the continuous metal plate before printing on die metal substrate.

Preferably, the adhesion enhancement agent is a petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum light aromatic solvent.

Preferably, the printing process is carried out by printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by printing nozzles moving in a print nozzle direction.

Preferably, the successive printing and curing steps are each associated with one pass of the printer.

Preferably, the metal substrate is a continuously fed metal plate.

Alternately, the metal substrate is of a finite length.

Alternately, the metal substrate is a three dimensionally shaped metal substrate.

Alternately, the metal substrate is a cast metal member.

Alternately, the metal substrate is a die cast metal member.

Alternately, die metal substrate is an extruded member. Alternatively, the metal substrate is a flat sheet of metal plate that has been cut to a pre-determined length.

Preferably, the method comprises the step of providing the metal substrate.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 150 degrees to each other or less.

Preferably, the digital printing process is controlled by a controller.

Preferably the controller is guided by software instructions.

Preferably, the digital printing process is an ink jet printing process.

Preferably, the digital printing process is an ink jet printing process whereby ink for the mask is sprayed out of nozzles in a controlled fashion.

Preferably, the printing process is carried out by a printing head.

Preferably, the printing head comprises one or more printing nozzles.

Preferably, the printing head comprises one or more printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by a printing head moving in a print head direction.

Preferably, ink is deposited by the printing nozzles in a print nozzle direction.

Preferably, the printing nozzles can deposit ink in a plurality of printing nozzle directions.

Preferably, the successive printing and curing steps are each associated with one or more passes of the printing head.

Preferably, the print head direction is at right angles to the direction of the feed of the continuously fed metal plate. Preferably, the controller is guided by instructions for digitally accounting for the feed movement of the metal substrate, to control the printing process to print the mask.

Preferably, the controller is guided by instructions for digitally accounting for movement of the metal substrate from said continuous feed.

Preferably, the controller receives a signal indicative of the movement of the metal substrate, and utilises this signal in the controlling of the digital printing process.

Preferably, the method comprises the step of providing the metal substrate.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 90 degrees to each ouier or less.

Preferably, the step of printing on the metal substrate comprises printing substantially to the edges of said metal substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate.

Preferably, the instructions guide the controller as to the profile of the metal substrate.

Preferably, the instructions guide die controller as to the two dimensional profile of the metal substrate.

Preferably, the instructions guide the controller as to the three dimensional profile of the metal substrate.

Preferably, the step of printing comprises the step of printing via a plurality of printing heads to reduce the number of printing passes required by each of the printing heads to print said mask. Preferably, the step of printing comprises the step of printing via a plurality of printing nozzles to reduce the number of printing passes required by said printing head to print said mask.

Preferably, the printing heads are reconfigurable to change the print nozzle direction of one or more of the associated printing nozzles.

Preferably, the printing heads are each movable in at least two dimensions to follow the profile of the substrate.

Preferably, the printing heads are movable in at least three dimensions to follow the profile of the substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate when guiding movement of the print nozzles.

Preferably, the method comprises detecting the distance from the metal substrate to a datum at a plurality of locations on the metal substrate.

Preferably the method comprises the step of compiling a profile of the metal substrate from the detected distances at said plurality of locations.

Preferably, the method comprises the step of controlling the printing process according to the detected profile.

Preferably, method comprises the step of controlling the movement of the printing head according to the detected profile.

Preferably, method comprises the step of controlling the operation of the printing head according to the detected profile.

Preferably, method comprises the step of controlling the printing nozzle direction according to the detected profile.

Preferably, the method comprises the step of controlling the print nozzles to remain within a printing distance of said metal substrate.

Preferably, the printing distance is between 0.1mm and 5 mm.

Preferably, the printing distance is between 0.5mm and 2 mm.

Preferably, the printing distance is about 1.2 mm.

In another aspect the invention may be said to btoadly consist in a method of masking a three dimensionally shaped metal substrate, comprising the steps of ^■ providing a three dimensionally shaped metal substrate; and

^■ digitally printing on said substrate in a printing process.

Preferably, the printing process is carried out by printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by printing nozzles moving in a print nozzle direction.

Preferably, the metal substrate is a continuously fed metal plate.

Alternately, the metal substrate is of a finite length.

Alternately, die metal substrate is a three dimensionally shaped metal substrate. Alternately, the metal substrate is a cast metal member.

Alternately, the metal substrate is a die cast metal member.

Alternately, the metal substrate is an extruded member.

Alternatively, the metal substrate is a flat sheet of metal plate that has been cut to a pre-determined length.

Preferably, the method comprises the step of providing the metal substrate.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces.

Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 150 degrees to each other or less.

Preferably, the digital printing process is controlled by a controller.

Preferably the controller is guided by software instructions.

Preferably, the digital printing process is an ink jet printing process. Preferably, the digital printing process is an ink jet printing process whereby ink suitable for masking is sprayed out of nozzles in a controlled fashion.

Preferably, the printing process is carried out by a printing head.

Preferably, the printing head comprises one or more printing nozzles. Preferably, the printing head comprises one or more printing nozzles that deposit ink under pressure.

Preferably, the printing process is carried out by a printing head moving in a print head direction.

Preferably, ink is deposited by the printing nozzles in a print nozzle direction.

Preferably, the printing nozzles can deposit ink in a plurality of printing nozzle directions.

Preferably, the method comprises the step of curing the digitally printed mask. Preferably, the step of curing the printed mask comprises at least one or more of the steps of:

^■ exposing at least part of the printed mask to radiation;

^■ heating at least part of the printed mask;

^■ exposing at least part of the printed mask to a chemical curing agent. Preferably, the radiation is ultra violet radiation.

Preferably, the step of printing the mask comprises a plurality of successive printing and curing steps.

Preferably, the successive printing and curing steps are each associated with one or more passes of the printing head.

Preferably, the printing head direction is at right angles to the direction of the feed of the continuously fed metal plate.

Preferably, the controller is guided by instructions for digitally accounting for the feed movement of the metal substrate, to control the printing process to print the mask.

Preferably, the controller is guided by instructions for digitally accounting for movement of the metal substrate from said continuous feed.

Preferably, the controller receives a signal indicative of the movement of the metal substrate, and utilises this signal in the controlling of the digital printing process.

Preferably, the method comprises the step of providing the metal substrate.

Preferably, the metal substrate is non planar.

Preferably, the metal substrate extends in three dimensions.

Preferably, the metal substrate comprises edges.

Preferably, the metal substrate comprises sharp edges.

Preferably, the metal substrate comprises ribbed surfaces. Preferably, the metal substrate comprises curved surfaces.

Preferably, the metal substrate comprises stepped surfaces.

Preferably, the metal substrate comprises curvilinear edges.

Preferably, the metal substrate comprises curved edges.

Preferably, the metal substrate comprises edges of planes extending at 90 degrees to each other or less.

Preferably, the step of printing on the metal substrate comprises printing substantially to the edges of said metal substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate.

Preferably, the instructions guide the controller as to the profile of the metal substrate.

Preferably, the instructions guide the controller as to the two dimensional profile of the metal substrate.

Preferably, the instructions guide the controller as to the three dimensional profile of the metal substrate.

Preferably, the step of printing comprises the step of printing via a plurality of printing heads to reduce the number of printing passes required by each of the printing heads to print said mask.

Preferably, the step of printing comprises the step of printing via a plurality of printing nozzles to reduce the number of printing passes required by said printing head to print said mask.

Preferably, the printing heads are reconfigurable to change the print nozzle direction of one or more of the associated printing nozzles.

Preferably, the printing heads are each movable in at least two dimensions to follow the profile of the substrate.

Preferably, the printing heads are movable in at least three dimensions to follow the profile of the substrate.

Preferably, the controller is guided by instructions for digitally accounting for the three dimensional shape of said metal substrate when guiding movement of the print nozzles.

Preferably, the method comprises detecting the distance from the metal substrate to a datum at a plurality of locations on the metal substrate. Preferably the method comprises the step of compiling a profile of the metal substrate from the detected distances at said plurality of locations.

Preferably, the method comprises the step of controlling the printing process according to the detected profile.

Preferably, method comprises the step of controlling the movement of the printing head according to the detected profile.

Preferably, method comprises the step of controlling the operation of the printing head according to the detected profile.

Preferably, method comprises the step of controlling the printing nozzle direction according to the detected profile.

Preferably, the method comprises the step of controlling the print nozzles to remain within a printing distance of said metal substrate.

Preferably, the printing distance is between 0.1mm and 5 mm.

Preferably, the printing distance is between 0.5mm and 2 mm.

Preferably, the printing distance is about 1.2 mm.

Preferably, the step of providing a three dimensionally shaped metal substrate comprises delivering it on a movable conveyor system.

Preferably, the method comprises the step of

^■ controlling the movement of the conveyor system

Preferably, the method comprises the step of

^■ controlling the movement of the conveyor system to coincide with the speed required for the printing process.

Preferably, the method comprises the step of

^■ accessing electronic patterns.

Preferably, the electronic patterns are stored on digital storage media.

Preferably, the method comprises the step of

^■ providing at least one or more electronic pattern over a network.

Preferably, the method comprises the step of

^■ manipulating the electronic patterns.

Preferably, the manipulation is by digital manipulation.

Preferably, the manipulation is account for the features of the three dimensional metal substrate, to present a substantially undisturbed pattern in at least one direction.

Preferably, the method comprises the step of ^■ controlling the movement of the printing heads.

Preferably, the method comprises the step of

^■ controlling the movement of the printing nozzles.

Preferably, the method comprises the step of

■ controlling the pivoting of the printing nozzles.

Preferably, the printing heads are movable by a moving mechanism.

Preferably, the moving mechanism comprises a frame.

Preferably, the moving mechanism comprises at least one or more linear actuators.

Preferably, the linear actuators are linear motors, or electric motors driving a rack and pinion type mechanism.

Preferably, the linear actuators are one or more selected from

^■ hydraulically operated,

^■ pneumatically operated, or

■ electrically operated

Preferably, the step of controlling movement of the printing head(s) is by feedback control.

Preferably, the step of controlling movement of the printing head(s) comprises receiving a signal from a displacement measuring transducer.

Preferably, the displacement measuring transducer is one or more selected form

^■ one or more linear displacement transducers; and

^■ one or more angular displacement transducers.

Preferably, the step of controlling movement of the printing head(s) comprises controlling the movement of the printing head by means of feedback loops using signals received from the displacement measuring transducer.

In another aspect the invention may be said to broadly consist in method of removal of a mask from a metal substrate, said method comprising one or more of the following steps:

^■ accelerating solid pellets of carbon dioxide towards the continuous metal plate to impinge upon the surface of the mask and/or continuous metal substrate; and

^■ subjecting the mask to an ultrasonic treatment.

Preferably, the method is for the removal of a mask in a continuous process. Preferably, the metal substrate is continuously fed on a continuous etching process line.

Preferably, the continuously fed metal substrate is one selected from:

^■ a continuous metal substrate;

" a continuous feed of individually cut metal substrate.

In another aspect the invention may be said to broadly consist in method of etching a metal substrate comprising the steps of

^■ providing a cast metal substrate;

^■ depositing a mask selectively onto the metal substrate, such that one or more masked regions and one or more un-masked regions are provided; and

^■ subjecting (or exposing) the metal substrate to an etching agent or agents for etching the un-masked regions of the metal substrate; and

^■ carrying out at least one or more selected from the following steps

o passivating at least part of the metal substrate; and

o coating at least part of the metal substrate, or at least a part of the substrate or at least a part of a surface of d e substrate, with a protective film or layer or surface or material.

Preferably, the metal substrate is die cast.

In another aspect the invention may be said to broadly consist in method of etching a metal substrate comprising the steps of

^■ providing an extruded metal substrate;

^■ depositing a mask selectively onto the metal substrate, such that one or more masked regions and one or more un-masked regions are provided; and

^■ subjecting (or exposing) the metal substrate to an etching agent or agents for etching the un-masked regions of the metal substrate; and

^■ carrying out at least one or more selected from the following steps

o passivating at least part of the metal substrate; and

o coating at least part of the metal substrate, or at least a part of the substrate or at least a part of a surface of the substrate, with a protective film or layer or surface or material. In another aspect the invention may be said to broadly consist in method of etching a metal substrate comprising the steps of

^■ providing a mill finished metal substrate;

^■ depositing a mask selectively onto the metal substrate, such that one or more masked regions and one or more un-masked regions are provided; and

^■ subjecting (or exposing) the metal substrate to an etching agent or agents for etching the un-masked regions of the metal substrate; and

^■ carrying out at least one or more selected from the following steps

o passivating at least part of the metal substrate; and o coating at least part of the metal substrate, or at least a part of the substrate or at least a part of a surface of die substrate, with a protective film or layer or surface or material.

Preferably, the step of passivating is the step of anodising.

Preferably, the metal substrate is Aluminium.

Preferably, the method of etching a metal substrate is carried out in a continuously fed process.

Preferably, the method of etching a metal substrate includes the step of coating at least part of the metal substrate.

Preferably, the metal substrate is provided as a continuous length of metal substrate that is fed continuously.

Preferably, the metal substrate is provided as continuous fed cut lengths of metal substrate.

Preferably, the method of etching includes at least partially removing the mask.

Preferably, the method of etching includes the steps of removing (such as by rinsing) the etching agent or agents from the metal substrate.

Preferably, the mill finished metal substrate is provided in a coiled form.

Preferably, at least the steps of masking and etching of the substrate is carried out in a continuous process, whereby the metal substrate is fed continuously along a production line.

Preferably, at least the steps of masking, etching of the substrate and removal of the mask is carried out in a continuous process. Preferably, at least the steps of masking, etching of the substrate and removal of the mask and anodising the metal substrate is carried out in a continuous process.

Preferably, the method of etching further comprises the step of

^■ coiling the metal substrate to provide an etched coil of metal substrate. Preferably, the coiled metal substrate is configured and/ or adapted for use in a subsequent industrial process.

Preferably, the step of coiling the metal substrate is carried out after passivation and/ or coating the metal substrate.

Preferably, the subsequent process is a laminate production process. In another aspect, the invention may be said to broadly consist in a method of enhancing the adhesion of a mask on a metal substrate, said method comprising the step of:

^■ applying an adhesion enhancement agent to said metal substrate before applying a mask onto the metal substrate.

Preferably, the metal substrate is mill finished.

Alternatively, the metal substrate has been pre-passivated.

Preferably, the metal substrate has been pre-anodised.

Preferably, the metal substrate has been pre-coated.

Alternatively, the metal substrate has been pre-coated and pre-anodised.

Preferably, the step of applying a mask onto the metal substrate is by digital printing.

Preferably, the adhesion enhancement agent promotes (or facilitates) adhesion of the mask to the metal substrate.

Preferably, the adhesion enhancement agent is a petroleum based solvent. Preferably, the adhesion enhancement agent is a naphtha petroleum based solvent.

Preferably, the adhesion enhancement agent is a naphtha petroleum light aromatic solvent.

Preferably, the method includes the step of heating or cooling said substrate before or after application of said adhesion enhancing agent.

Preferably, the method includes the step of washing or rinsing the metal substrate. Preferably, the step of washing or rinsing the metal substrate can be carried out between any of the other steps.

In another aspect, the invention may be said to btoadly consist in a production line for etching a metal substrate, said production line comprising

" a feed arrangement adapted and configured for receiving a coiled metal substrate and feeding it out operationally in a continuous manner; and ■ a printer for continuously printing a mask on the continuously fed metal substrate.

Preferably, the metal substrate is metal sheeting or metal plating.

Preferably, the printer is a digital printer, capable of printing in a digital printing process.

Preferably, the digital printing process prints the mask onto the continuous metal plate by an ink jet printing process.

Preferably, the printer is a flatbed printer.

Preferably, digital printing is performed by digital printing technologies, for example thermal transfer printing, ink jet printing, phase change or hot melt ink type printing. It will be appreciated thermal transfer printing is generally understood to involve a dry transfer printing process involving a combination of heat and pressure to bond a printable composition to a media. Where for example phase change, hot melt or ink jet type printers are to be used, the composition to be printed composition can be designed to have the appropriate properties to enable this process for printing on to the metal substrate.

Preferably, the digital printing process is controlled by a controller.

Preferably, the controller is guided by instructions for digitally accounting for continuous movement of the continuous metal substrate.

Preferably, the controller receives a signal indicative of the movement of the continuous metal substrate, and utilises this signal in the controlling of the digital printing process.

Preferably, the production line comprises an adhesion enhancement agent applicator for applying adhesion enhancing agent to the continuous metal substrate before printing.

Preferably, the production line includes a drive means for feeding the metal substrate continuously along the production line. Preferably, the drive means is a drive roller, a conveyor system, or any other suitable drive means.

Preferably, the adhesion enhancement agent appHcator is one or more selected from

■ dip tank,

^■ a spraying system (or sprayer),

^■ a roller-type applicator, and

^■ any other suitable means.

Preferably, the production line comprises a curing arrangement for operationally speeding up the curing of the printed mask.

Preferably, the curing arrangement comprises an ultraviolet radiation exposure system.

Preferably, the production line comprises an etching agent applicator for applying an etching agent or agents to at least part of metal substrate.

Preferably, the etching agent applicator comprises one or more selected from

^■ dip tank,

^■ a spraying system (or sprayer),

^■ a roller— type applicator, and

^■ any other suitable means.

Preferably, the production line comprises a wash or rinse system for washing or rinsing the etching agent or agents from the masked metal substrate.

Preferably, the rinsing system is configured and adapted to rinse the metal substrate several times between any of the processes.

Preferably, the rinsing system comprises one or more selected from

■ dip tank,

^■ a spraying system (or sprayer),

^■ a roller— type applicator, and

^■ any other suitable means.

Preferably, the production line comprises a cutting arrangement for operationally cutting the continuous metal substrate into pre-determined lengths.

Alternately, production line is adapted and configured to process the continuous metal substrate without cutting it.

Preferably, the cutting arrangement is a flying shear. Preferably, the production line comprises a mask removal system for removal of said mask from said metal substrate.

Preferably, the mask removal system comprises one or more selected from

^■ a dry ice blasting apparatus; and

" an ultrasound transmitter.

Preferably, the production line comprises a passivation system for passivating the metal substrate.

Preferably, the production line comprises a coating system for at least partially coating the metal substrate with a protective film or layer.

Preferably, the protective film or layer is at least one or more selected from:

^■ transparent;

^■ semi-transparent;

^■ translucent;

^■ coloured.

Preferably, the passivation of the metal substrate is by one or more selected from

^■ anodisation

^■ any other suitable treatment.

Preferably, the passivation system includes one or more selected from a ■ dip tank;

^■ spraying system (or sprayer); and

^■ roller coating system (or roller applicator).

Preferably, the coating system includes one or more selected from a

^■ dip tank;

■ spraying system or sprayer); and

^■ roller coating system (or roller applicator).

Preferably, the production line comprises a metal substrate coiling system for coiling a continuously fed metal substrate into a coil for use in a subsequent process.

Preferably, the subsequent process is a laminate forming process.

Preferably, the metal substrate is between 0.2mm to about 4.0mm thick (or gauge).

Preferably, the metal substrate is between 0.6mm to about 3.0mm thick (or gauge). Preferably, the production line comprises a cleaning system.

Preferably, the cleaning system comprises one or more selected from

^■ a bath,

^■ a spray system, and

" an applicator system.

Preferably, the cleaning system is configured and adapted for washing and/ or removing contaminants from the metal substrate by applying one or more selected from

^■ a solvent,

^■ a mild acid; and

" a degreaser.

Preferably, the cleaning system is disposed to clean the metal substrate before printing.

Preferably, the cleaning system is disposed to clean the metal substrate before application of the adhesion enhancement agent.

Alternatively, the cleaning system is disposed to clean the metal substrate before the application of the etching agent or agents.

Preferably, the production line comprises a stacking system for stacking lengths of metal substrate that have been cut to length.

In another aspect, the invention may be said to broadly consist in an etched metal substrate produced according to any of the aspects of the invention above.

Preferably, the etched metal substrate is a coiled etched metal substrate. Other aspects of the invention may become apparent from the following description which is given by way of example only and with reference to the accompanying drawings.

As used herein the term "and/ or" means "and" or "or", or both.

As used herein "(s)" following a noun means the plural and/ or singular forms of the noun.

The term "comprising" as used in this specification means "consisting at least in part of. When interpreting statements in this specification which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present. Related terms such as "comprise" and "comprised" are to be interpreted in the same manner. The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference.

To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and die descriptions herein are purely illustrative and are not intended to be in any sense limiting.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described by way of example only and with reference to the drawings in which:

Figure 1: shows a schematic diagram of a first embodiment of an etching process;

Figure 2: shows a schematic diagram of a second embodiment of an etching process; Figure 3: shows a schematic diagram of a third embodiment of an etching process;

Figure 4: shows a schematic diagram of a fourth embodiment of an etching process for a three dimensional metal substrate;

Figure 5: shows a masking apparatus for use in a masking process; Figure 6: shows a side view of a three dimensionally configured or shaped metal substrate;

Figure 7: shows a top perspective view of the three dimensionally configured or shaped metal substrate of figure 6;

Figure 8: shows a top view of the three dimensionally configured or shaped metal substrate of figure 6;

Figure 9: shows a side view of a three dimensionally configured or shaped metal substrate;

Figure 10: shows a top view of the three dimensionally configured or shaped metal substrate of figure 9 from viewpoint B;

Figure 11: shows a top view of the three dimensionally configured or shaped metal substrate of figure 9 from viewpoint C;

Figure 12: shows a top perspective view of the three dimensionally configured or shaped metal substrate of figure 9; and Figute 13: shows a schematic diagram of a fourth embodiment of an etching process for a three dimensional metal substrate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT (S))

With reference to the above drawings, in which similar features are generally indicated by similar numerals, a production line according to one aspect of the invention is generally indicated by the numeral 1000.

In one embodiment now described, and as shown in figure 1, there is provided a production line 1000 for the production of an etched metal substrate is provided. The production line 1000 comprises a feed arrangement 100 and a printer 200.

In one embodiment, shown in figures 2 and 3 the feed arrangement 100 is adapted and configured for receiving a coiled metal substrate 2000 and feeding it out continuously by means of drive rollers 150 or similar.

It should be understood that where reference is made to the use of anodisation, this would have particular reference to the processing of an aluminium substrate, since aluminium may be readily commercially anodised. However, it is envisaged that the methods and processes and apparatus described can have reference to other metal substrates, such as, but not limited to, steel, galvanised steel, stainless steel, copper, zinc, tantalum, titanium, magnesium, niobium, and tantalum, as well as alloys thereof.

In an alternative arrangement shown in figure 1 the feed arrangement 100 is configured and adapted for feeding the metal substrate (at least partially along the production line) as individual cut lengths of metal substrate. The feed arrangement 100 can include a jigging system 170 for handling individually cut lengths of metal substrate during the various process steps. The jigging system 170 may be automated. Individual cut lengths may be cut to pre-deterrnined lengths according to customer requirements or for speciality sizing or other applications.

It is envisaged that the coiled metal substrate 2000 could be pre-anodised, or could be a mill finished coil of metal without any pre-treatment or passivation, or mill finished, and optionally passivated and/ or coloured. It is envisaged that the coiled metal substrate 2000 could be composed of any of the metals that are typically used in the production of laminates and/ or facades, such as aluminium, zinc, copper, mild steel, galvanised steel, zincalume, stainless steel, titanium or any other suitable metal, as well as any alloys of these (and in particular titanium alloys). In one embodiment, the metal substrate is about 0.2mm to about 4.mm thick, and more preferably about 0.6mm to about 3.0mm thick.

In the description below, it should be noted that when a continuous feed is discussed, this can apply to the continuous feed of a continuous metal substrate, such as metal sheeting or plate or metalised substrate in sheet form, or to the continuous feed of a plurality of metal substrate sheets or plates that have been cut to length. For the sake of clarity, the cut metal sheets and/ or continuous metal sheet or metalised substrate are referred to as "metal substrate". It should also be appreciated the term "metal substrate" includes metals, metal alloys, and metalised substrates (using various techniques, including, but not limited to techniques such as vacuum deposition of metal or metal alloys). As shown in figure 4, and described below it is also anticipated that metal substrate could refer to a three dimensionally shaped metal or metalised member such as an aluminium extrusion or moulded aluminium member or die cast member, or a plastic or other material that has been coated or dipped or sprayed, or d e like.

In one embodiment, the printer 200 that is anticipated as being used to print on a planar feed of coiled metal substrate is preferably a digital flatbed printer. The digital flatbed printer is adapted and configured for continuously printing a mask (not shown) on the continuous metal substrate in a digital printing process. It is envisaged that the printer 200 will be controlled by a controller (not shown). The controller will be guided by instructions in the form of software, so diat it can account for continuous movement (which may be in the form of constant or periodic discrete movement) of the metal substrate. In one embodiment, it is envisaged that the controller, and hence the printer 200, can be guided by software that receives an input signal (not shown) indicative of the movement of the metal substrate along the process line, and utilises this signal in the controlling of the digital printing process. In a more preferred embodiment, it is envisaged that the printer 200 will be a digital flatbed printer similar to types currently provided by Oce™ or Hewlett Packard™.

Such a printer 200 is capable of digital printing on metal substrate, using a wide variety of ink masks, including, but not limited to, a product such as Coats X206. In particular, it is envisaged that preferably inks that are curable by means of exposure to heat and/ or ultraviolet (UV) radiation will be preferred.

Alternatively, it is envisaged that curing of the ink could be by any one or more of the steps of exposing the printed ink or metal substrate to any other radiation (such as infra-red radiation), heating at least part of the printed ink or metal substrate by exposing it to heated fluid such as air or gas; and exposing at least part of the printed mask to a suitable curing chemical agent via a curing chemical applicator.

In this regard, it is envisaged that the production line 1000 could include a curing arrangement 300. The curing arrangement 300 could be associated with the printer 200, or could be a standalone-type arrangement. The printer 200 will be used to print a mask on the metal substrate, after which the at least partially printed mask will be exposed to the UV light of the curing arrangement to speed up the rate of curing of the ink. In one embodiment, the printing of the mask can comprise many successive printing and curing steps. In one embodiment, it is envisaged that the successive printing and / or curing steps could be a carried out with each successive pass of a printing head of the printer.

It is also envisaged that prior to the application of the adhesion enhancement agent, the metal substrate could be pre-heated by heaters to make it more receptive to the adhesion enhancement agent, and in turn facilitate better adhesion of the ink.

It is envisaged that by using a digital printer of high resolution, in which the ink droplets are finely and accurately controllable, accurate control of the printing and curing process may be achieved. Control of the curing process is also envisaged, such as by controlling the intensity and/ or time and/ or number of exposures of the ink to radiation.

It should be noted that the benefits that the use of such digital printing and/or curing on a metal substrate can provide, may also be applicable in the printing of masks (for the purposes of selective etching) on cut lengths of metal substrate in a batch processing-type production line, or when there is a continuous feed of cut plates through the printer.

The production line 1000 further comprises an adhesion enhancement agent applicator 400 for applying adhesion enhancing agent to the metal substrate before printing. This could be in the form of a dip tank (not shown), a spraying system (not shown), an applicator roller (not shown) or any other suitable applicator arrangement. The application of such an adhesion enhancement agent will allow the inks printed by the printer 200 to better adhere to the metal substrate, and may also allow the ink to cure faster. It is also envisaged that the production line 100 could include heaters (not shown) for pre-heating or post-heating the metal substrate prior to or after application of the adhesion enhancement agent. In another embodiment, heaters (not shown) could also be provided for heating of the metal substrate after printing of the mask, or at discrete steps during printing of the mask.

It is envisaged that any such heating would preferably be by blowing heated air onto the metal substrate, or by heating of the metal substrate from an opposed side by direct exposure to a heated fluid such as gas or air.

In one embodiment, the adhesion enhancer is a petroleum based solvent, and in particular a naptha petroleum based light aromatic solvent.

In one embodiment, the production line 1000 can include a cutting arrangement 450, such as a flying shear, for cutting the continuous metal substrate into lengths before or after printing or curing has occurred, (as shown in figure 1).

However, this need not necessarily be the case, and the continuous metal substrate could merely be fed continuously into the next stage as shown in figures 2 and 3. For this reason, reference will from now on be made to a metal substrate, on the understanding that it may be continuously fed as a continuous metal substrate, or cut to lengths.

Optionally, and preferably before the printing of the mask onto the metal substrate, the production line 1000 can comprise a cleaning system 160. The cleaning system 160 could be in the form of a bath, a spray system, or a roller applicator. It is envisaged that the cleaning system could apply one or more of a solvent, a degreaser or a mild acid to remove contaminants such as dirt and mill oils. This will depend largely on the state, material and origin of the metal substrate.

At the next stage, the production line 1000 further comprises an etching agent applicator 500 for applying an etching agent or agents to at least part of metal substrate. Such an etching agent is generally understood to be a corrosive agent can be any agent that is suitable for use in an etching process. The etching agent applicator 500 can be any one or more selected from a dip tank 510, a spraying system (not shown), and a roller— type applicator (not shown), or any other suitable means, as long as the applicator 500 allows the etching agent to effectively cover at least part of the unmasked surface area of the metal substrate for a long enough period to effectively etch the metal substrate.

The etching agent is then rinsed off by a washing or rinsing system 600. The rinsing system 600 can be one, or a series of, any one or more selected from a dip tank, a spraying system, or a squeegee (or other mechanical type)-type agent removal system. The rinsing system 600 is for rinsing the etching agent from the masked metal substrate. It is to be understood that the metal substrate can be dunked alone o with others as cut metal plate in a batch-type system, or continuously fed though the rinsing system as a continuous metal substrate.

The production line 1000 further line comprises a mask removal system 700 for removing the printed mask from the metal substrate. In a preferred embodiment, the mask removal system 700 will also be applicable to a feed of continuous metal substrate.

It is envisaged that in a preferred embodiment, the mask removal system 700 will comprise one or more selected from a dry ice blasting apparatus (not shown); and an ultrasound transmitter (not shown). Alternately, more traditional mechanical or solvent based mask removal can be used. It is also envisaged that the metal substrate can be rinsed off by the rinsing system 600 after the mask removal step.

However, the use of dry ice blasting apparatus and/or an ultrasound transmitter will allow for the removal of the mask without creating additional waste that needs to be removed (in addition to the removed mask). Such systems are also preferred to the traditional use of solvents.

Dry ice blasting involves the accelerating of solid pellets of carbon dioxide towards the continuous metal plate to impinge upon the surface of the mask and/or continuous metal plate. The impingement of the sokd carbon dioxide pellets on the surface of the mask and/ or continuous metal plate causes it to sublimate. Such sublimation of the carbon dioxide pellets absorbs a large volume of heat from the surface, producing shear stresses due to thermal shock. It also makes the mask brittle, as well as cause it to shrink and contract, causing delamination.

This dry ice blasting process will improve cleaning also as the mask is expected to transfer more heat than the underlying substrate and flake off more easily, and also because of the physical abrasion of the pellets against the mask.

The efficiency and effectiveness of this process depends on the thermal conductivity of the substrate and mask. The rapid change in state from solid to gas is thought to cause microscopic shock waves, which are also thought to assist in removing the contaminant.

The ultrasound transmitter will cause ultrasound waves to impinge upon the surface of the mask and/ or continuous metal plate in an ultrasound beam. Preferably, the ultrasound beam is of a frequency above 20kHz. More preferably, the ultrasound beam is of a frequency above 150kHz, and most preferably between 150-400kHz.

The use of traditional mask removal solvents (such as petrol, turpentine, diethyl acetate, acetone, etc.) in a large scale industrial etching process can be undesirable as it creates dangers from fumes given off by such solvents, including fire and asphyxiation hazards. The use of such solvents on a large scale may also require in-depth safety procedures and planning, and can even restrict the ultimate location of the production line 1000 to remote industrial areas deemed safe to the public.

Once the mask has been removed from the metal substrate, it is envisaged that in one embodiment of the production line 1000, the metal substrate will then be subjected to passivation in a passivation system 800.

It is envisaged that passivation could be by means of a chemical or electro chemical treatment, such as anodisation.

It is also envisaged that a protective coating could also or alternatively be applied to the etched metal substrate by means of a coating applicator 850. Such a coating (such as a lacquer top coat) could be translucent, transparent or semi transparent coating, and could also be coloured.

Such a protective coating would typically be applied to the metal substrate after the mask has been removed. Passivation (including but not limited to anodisation) can also be carried out after the mask has been removed, however this need not necessarily be the case. It could be carried out before the mask is removed (particularly if the metal substrate initially provided was already anodised or otherwise passivated.

Where the initial metal substrate 2000 was supplied already anodised, then the bare metal of the newly etched substrate will be exposed. Further anodisation will allow for this newly etched metal to have a clear or coloured oxide layer coated on top of it, to allow it to be more resistant to corrosion.

When the original metal plate is supplied as a pre-anodised metal plate, then further anodisation could also result in the introduction of an additional textured/ coloured surface as shown in figure 2.

Where the initial metal substrate 2000 was supplied with a mill finish, then the newly exposed etched metal as well as the newly unmasked mill finish needs to be protected by passivation, as shown in figure 3. In one embodiment, shown in figure 3, passivation may be by an anodisation process. This would typically be the case where the metal substrate is composed of aluminium.

In another embodiment, instead of passivation, a clear coat of lacquer or paint or powder coating could be applied. The coat can be transparent, translucent or semi- transparent, and could also be coloured.

In yet another embodiment, it is envisaged that the metal substrate can be anodised as well as coated with a protective layer.

At this stage, where the metal substrate 2000 has been cut into lengths, the lengths of metal substrate can be stacked for transport by the automated jigging system 170. However, where the metal substrate has been maintained as a continuous metal substrate, then the production line 1000 can include a coiling system 900 for coiling the continuously fed metal substrate into a coil.

In this way, an etched metal substrate in the form of a coil can be presented for use in subsequent use in other continuous-type processes, such as the production of internal laminates or external facades for use in building cladding, or other industries.

The processes, methods and apparatuses described above allow for the large scale manufacturing of an etched metal sheeting product (whether coiled or cut to lengths) that may be produced with reduced production time, and increased safety aspects, and with reduced space and stock holding requirements.

Typically when cut sheets of metal substrate are used as a starting point, the metal substrate is required to be cut to lengths beforehand. This is typically carried out in a separate cutting facility. But, because of the typical time lapse between cutting, transport and eventual etching, the cut sheeting may be subjected to an initial passivation (or anodisation) process. After etching, the metal substrate is required to be subjected to a second passivation process.

The apparatus described above allows for the use of mill finished metal substrate as starting pint, and the production of etched metal substrate (in flat sheets or coiled metal sheets) in a large scale manufacturing process that has only been subjected to a single anodisation /passivation /lacquering /clear coat /topcoat process, thereby reducing production costs. This process also allows for the provision of bright metal/matt metal etched metal substrate in a large scale production process to increase pattern contrast and provide a desirable aesthetic or decorative effect. Further the process described above allows for flexibility of manufacture, since designs sent in by customers can be easily printed and manufactured, without the effort involved in having screens made beforehand. The process also allows for the production of custom patterns and branding without the setup costs of screen sprinting.

The continuous production process described above also allows for short, and even one-off, production runs of varying lengths of metal substrate, without incurring costs for cut-offs.

In another embodiment as shown in figures 4 to 13, the production line need not receive a continuous feed of planar metal substrate from a coil, or even cut sheets of planar material. In figure 4 a 3D metal substrate 2000 such as an aluminium extrusion of a finite length, is moved continuously along a conveyor system 110.

However in figure 13, a 3D metal substrate 2000 such as an aluminium extrusion of a finite length, is provided without it being moved continuously. This is typically known as batch processing.

In this embodiment, it is envisaged that the flexibility of masking (for the purposes of providing a mask for further etching) allowed by the use of a digital mask printing process can allow for the masking of three dimensionally configured metal or metalised objects or items. Such items include, but are not limited to cast aluminium members, aluminium extrusions or sheet, machined pieces, or any other three dimensional objects on which metal has been coated, for example by way of dipping, spraying, electrode position, or any other suitable process. For the purposes of clarity and consistency within the specification, such three dimensionally shaped metal or metalised items shall also be referred to as a "metal substrate" 2000.

In a preferred embodiment, the production line show in figure 4 includes a masking apparatus in the nature of a digital printer (and hereinafter called a printer 200 in order to be consistent with the terminology and reference numerals used above), in that it preferably uses a digital inkjet-type printing process. In such a process, ink suitable for use as a mask for etching is deposited on the metal substrate under pressure via one or more, and preferably many, printing nozzles 220 that are located on a printing head 210 (as shown in figure 5).

The operation of the printing head 210 and printing nozzles 220 are under control of at least one controller 230. In a preferred embodiment, the controller 230 could be a computer 240, a Programmable Logic Controller (PLC), or the like. In particular, the controller 230 controls the movement of the printing head, 210 and the deposition of the ink from the printing head 210 and printing nozzles 220. In order to achieve its functions it is envisaged that the controller will include a processor (not shown) such as that found in a computer 240, a transmitter (not shown) and a receiver (not shown). The transmitter and/ or receiver could for example, be a network card (not shown) on the computer 240, or any other suitable mechanism.

The controller 230 is controlled by instructions in the form of software that is stored on a digital storage media, such as a hard disk of a computer 240, or server, or similar.

In the embodiment shown in figure 4, the metal substrate is moved along the process line by means of a conveyor system 110 or similar moving mechanism to provide the metal substrate for the printer 200 to print on. However, it is envisaged that such a conveyor system 110 will be able to move the metal substrate 2000 accurately along the process line for reasons that will be explained later.

The software is configured and adapted to guide the controller 230 to control the movement of preferably a plurality of printing heads 210 to vary the distance from the printing head 210 to the metal substrate, and in at least two dimensions for printing on the three dimensional metal substrate 2000.

The printing head 210 is typically movable by the controller 230 in a reciprocal fashion in a printing head direction, which is preferably perpendicularly to the direction of movement of the metal substrate 2000 (shown as arrow F in figure 5) and horizontally. This will depend on how the substrate is provided. If the substrate is moving in a feed direction, the printer 200 may comprise a plurality of printing heads 210 that cover the entire width of the substrate (and therefor do not need to move horizontally and transverse to the feed direction) then the printing heads 210 need only move in transversely to the feed direction in a vertical direction towards the substrate and away from the metal substrate 2000(i.e. vertically in figure 5).

However, in alternative embodiments, the printing head 210 can also move reciprocatingly in at least a small distance in a direction parallel to the direction of movement of the metal substrate 2000.

In this regard, it is envisaged that when the metal substrate 2000 is moved along conveyor system 110 horizontally, the controller will control at least the height of the printing head 210 to ensure that formations presented in three dimensions on the metal substrate (shown in figure 5 as a zigzag formations) do not make contact with the printing head, to thereby potentially cause damage to it.

The controller 230 can also be guided by the software to control the movement of the conveyor system 110, to coincide with the speed required for the printing process, where complex printing processes are to be carried out— for example where the three dimensional formations present complex shapes, or a complex mask pattern is to be printed on the metal substrate 2000.

It is envisaged that the software will be adapted and configured to guide the controller 230 to access electronic patterns that may also be stored on digital storage media such as databases (not shown). The patterns could alternatively be provided over a network in real time. The controller 230 in turn is preferably guided by the software to manipulate the patterns as described below.

It is envisaged that the printing nozzles 220 on the printing head 210 can be pivotally moveable (the pivoting movement shown as arrow P on figure 5, with broken lines indicating potential pivoted states of die printing nozzles). Either the printing nozzles can be pivotally moveable on the printing head 210, or the entire printing head 210 can be pivotable, to thereby change the direction (the printing nozzle direction) in which ink is deposited on the metal substrate 2000. In one embodiment, the printing nozzles may be pivoted by an electric motor (not shown) acting on a gear mechanism (not shown) to pivot the printing nozzles 220. In this way, the printing nozzles 220 can be pivoted to deposit ink in two or more printing nozzle directions.

It is envisaged that this pivotability of the printing nozzle direction will allow the controller 230 to control the angle of printing of the print nozzles, to allow the printer to print accurately on angled surfaces of the metal substrate 2000.

The printing head is moved by moving mechanism in the form of a frame (not shown) on which the printing head 210 is movable, preferably by linear actuators (not shown) such as linear motors, or electric motors driving a rack and pinion type

mechanism(not shown) or worm gear type mechanism (not shown). In another embodiment the linear actuators could be hydraulically operated, pneumatically operated, or electrically operated.

The printer 200 preferably includes displacement measuring transducer such as linear or angular displacement transducers (not shown). The movement of the printing heads may be controlled by the controller by means of feedback loops using signals received from the displacement transducers.

In one embodiment, the printer 200 can include a distance measurement means 250 for providing a height signal indicative of the distance of the metal substrate relative to a fixed datum. The distance measurement means can be one of a wide variety of known distance measurement transducers, such as laser distance transducers, or the like. In one embodiment, the distance measurement means 250 is configured to scan the area of the metal substrate 2000, and to send a signal indicative of the measured distance from the substrate to the datum at a series of locations as a set of measurements. This set of measurements is used to determine either three dimensional profile of the metal substrate, or a two dimensional profile of the metal substrate 2000 in a particular direction.

It is envisaged that the instructions will be configured to guide the controller 230 to use the height signal and/ or the profile signal to control any one or more of:

^■ the alignment of the printing head;

■ the location of the printing head;

^■ movement of the printing head

^■ the angle of deposition of ink from the printing head and/ or printing nozzle;

^■ the rate of movement of the printing head;

^■ the rate of deposition of ink by any of the printing nozzles;

■ the pattern to be deposited by said printing head.

In this way, the control of the printing head 210 and printing nozzles 220 can be automated, especially if the conveyor system is not accurately controlled so that the whereabouts of the profile of the substrate is not known to the controller 230.

It is envisaged that the controller would use the detected substrate profile to prevent the printing head 210 being damaged by the substrate, and to ensure that the printing head can be held at an appropriate distance from the substrate 2000 to ensure accurate printing onto the substrate.

In addition, it is envisaged that the controller maybe guided by the software to control the movement of the conveyor system 110. The conveyor system 110 can include a speed or movement transducer that sends a conveyor signal to the controller. This conveyor signal can be used as described below. In one embodiment, the result of which is illustrated in figures 6, 7 and 8, the instructions can be configured for modifying the pattern to be deposited by the printing head according to the profile of the metal substrate. In this way, the resultant pattern seen by users (not shown) standing away from the substrate 2000 (for example seeing the substrate from viewpoint A in figure 6) could, for example, be seen as regular and smooth (as seen in figure 8), while the actual contours of the pattern deposited on the substrate are in fact irregular and zigzagged (as seen in figure 7). In this way, the user sees the pattern the way it would have looked like if the substrate 2000 had not been three dimensional. Such a process could be a carried out automatically by the software guiding the controller 230.

In another embodiment, the software could be configured for guiding the controller to deposit the ink to mask the metal substrate in one of two or more different patterns or words or signage, where each pattern is deposited on associated surfaces. The associated surfaces may, for example, each be aligned at a particular angle (as shown in figures 9, 10, 11 and 12). In this way, when a user stands at an angle relative to the substrate where only one type of associate surface marked b in figure 9 is visible, for example when viewing the substrate form the viewpoint of arrow B in figure 9, then one pattern is visible (as shown in figure 10). However when the substrate is viewed from the viewpoint of angle C in figure 9, then a different pattern is seen (as shown in figure 11) as only surfaces marked c can be seen from that viewpoint. Such a process could be a carried out automatically by the software guiding the controller 230.

The control of the deposition of masks to create such patterning or combinations of patterning is advantageous as it can facilitate the creation of desirable aesthetics when the metal substrate2000 is then used as architectural cladding for buildings and the like.

In one embodiment, the user could select one of a number of different patters from a pattern library, or provide their own patterns over a network, for depositing on one or more surfaces of the substrate 2000. Preferably the pattern library comprises predetermined images of: a lot number, a serial number, an identification number, a date or a time indication, a name, a logo, a trade mark, a make, a model, a manufacturer, a product identifier, an image, a photographic replication, a decoration, an artistic drawing, a design, a repeating pattern, a unique decorative identifier image. The user could also select the particular surfaces (which may have been scanned to produce a profile represented graphically for selection by a user) on which particular patterns are to be deposited. The controller 230 will then be guided by the software in accordance with the selection made by the user, and will control the printing head to deposit the selected mask pattern onto the selected surfaces.

In this way, it is envisaged that metal substrates 2000 of a wide variety of configurations and shapes can be masked for etching. The metal substrates 2000 could include non planar surfaces, surfaces with edges (including sharp edges), ribbed surfaces, curved surfaces, stepped surfaces, curvilinear edges, and/or curved edges. The location and movement of the printer head 210 can be controlled by the controller 230 to keep the printer head 210 a safe printing distance from the metal substrate, while facilitating the accurate deposition of ink.. Such a safe printing distance would typically be in the order of between 0.1mm and 5 mm, more preferably between 0.5mm and 2 mm, and most preferably about 1.2 mm.

The conveyor signal indicative of the speed or movement of the conveyor system 110 can be used in a feedback loop to control the conveyor system's 110 speed or movement, or the conveyor signal could be used to calculate required movement of the printer heads 210 to allow for the conveyor system 110 speed to accurately print the required patterns.

It should be appreciated the term "metal substrate" includes metals, metal alloys, and metalised substrates (using various techniques, including, but not limited to techniques such as vacuum deposition of metal or metal alloys).

Where in the foregoing description reference has been made to elements or integers having known equivalents, then such equivalents are included as if they were individually set forth.

Although the invention has been described by way of example and with reference to particular embodiments, it is to be understood that modifications and/ or improvements may be made without departing from the scope or spirit of the invention.

In addition, where features or aspects of the invention are described in terms of Markush groups, those skilled in the art will recognise that the invention is also thereby described in terms of any individual member or subgroup of members of the Markush group.