RELATED APPLICATIONS

[0001] This application claims convention priority from Australian Provisional Patent Application No. 2022901320, the contents of which are incorporated herein in their entirety by reference thereto.

FIELD

[0002] This invention relates to methods of printing waterslide decals and applying waterslide decals to an object surface.

BACKGROUND

[0003] Decorating three-dimensional (3D) objects with high fidelity two-dimensional (2D) features is a challenging task, particularly when attempting to do so consistently for a large number of 3D objects. A known method for applying 2D features, or art, to objects is the application of a waterslide decal. The desired 2D features are printed using a water-soluble adhesive onto a substrate and lowered into a waterbath, the 2D features separate from the substrate. The 2D features are then removed from the waterbath and placed on the object surface. While the 2D features remain hydrated, the 2D features remain moveable with respect to the object surface.

[0004] Traditionally, this method is unsuitable for decorating 3D objects experiencing wear and tear, and is also unsuitable for providing 3D objects with 3D surface features, such as texture.

SUMMARY

[0005] It is an object of the present invention to at least substantially address one or more of the above disadvantages, or at least provide a useful alternative to the above discussed waterslide decal methods.

[0006] In a first aspect the present invention provides a method of manufacturing a waterslide decal to be applied to a kitchen appliance, the decal depicting an image, the method including the steps of: screen printing an adhesive bottom layer; printing one or more colour layers on the adhesive layer; screen printing one or more transparent texture layers on the last colour layer; and wherein the one or more transparent texture layers provide height to some portions of the decal compared to other portions of the decal.

[0007] Preferably, the method further includes the step of: screen printing one or more white layers between the adhesive layer and the colour layers.

[0008] Preferably, the method further includes the step of: screen printing a removable film on the last texture layer.

[0009] Preferably, the step of printing one or more colour layers includes screen printing one or more monochrome colour layers.

[0010] Preferably, the step of printing one or more colour layers includes offset printing one or more spot colour layers.

[0011] Preferably, the step of printing one or more colour layers includes offset printing one or more CMYK colour layers.

[0012] Preferably, the method further includes the steps of: providing a base object having a base image, the base image having 2D features and 3D features; preparing an image information by photogrammetric analysis of the base object, the image information having 2D information relating to the 2D features and 3D information relating to the 3D features; preparing a UV mapped image by UV mapping of the image information and dividing the UV mapped image into one or more waterslide decal specifications, each waterslide decal specification having 2D specification relating to the 2D information for the steps of printing the colour layers, and 3D specification relating to the 3D information for the step of printing the one or more transparent texture layers.

[0013] Preferably, the image information is modified prior to the preparation of the UV mapped image to add lighting features to the 2D information based on the 3D information by adding a light source to the image information prior to the step of preparing the UV mapped image. [0014] Preferably, the 2D information is modified to match a colour information in the 2D information to one or more of the colour layers.

[0015] In a second aspect, the present invention provides a waterslide decal depicting an image for application to an object surface, the waterslide decal including: an adhesive bottom layer; one or more colour layers on the last white layer; one or more transparent texture layers on the last colour layer; and wherein the one or more transparent texture layers provide height to some portions of the decal compared to other portions of the decal.

[0016] Preferably, a location of the waterslide where the one or more transparent texture layers provides height corresponds to brushstrokes on the image.

[0017] In a third aspect, the present invention provides a method of applying a waterslide decal to an object surface, the method including the steps of: applying a polyurethane basecoat to the object surface to improve adhesion between the object surface and the decal; soaking the decal in a water bath, such that the decal hydrates and separates from a substrate; removing the hydrated decal from the water bath; transferring the decal to the object surface; applying a polyurethane topcoat to the object surface to improve survivability of the decal on the object surface.

[0018] Preferably, the method further includes the step of drying the polyurethane basecoat for between 30 to 40 minutes at a temperature between 65 °C - 75 °C.

[0019] Preferably, the method further includes the step of cleaning the object surface with an alcohol or surface detergent, such as 2 -Butoxy ethanol.

[0020] Preferably, the method further includes the step of applying a paint basecoat prior to the step of applying the polyurethane basecoat, wherein the step of applying the paint basecoat further includes the step of drying the paint basecoat for 30 to 40 minutes at a temperature between 65 °C - 130 °C. [0021] Preferably, after the step of transferring the decal to the object surface, the method further includes the step of drying the decal for between 35 to 65 minutes at a temperature between 70 °C - 160 °C.

[0022] Preferably, the method further includes the step of drying the polyurethane topcoat for between 30 to 40 minutes at a temperature between 65 °C - 75 °C.

[0023] In a fourth aspect, the present invention provides a kitchen appliance decorated with a waterslide decal using the method of the third aspect.

BRIEF DESCRIPTION OF THE DRAWING

[0024] Preferred embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, wherein:

[0025] FIG. 1 shows a flow chart of a method of printing a waterslide decal according to a preferred embodiment of the invention.

[0026] FIG. 2 shows a schematic diagram of the structure of the waterslide decal printed with the method of FIG. 1.

[0027] FIG. 3 shows a flow chart of a method of preparing a waterslide decal specification used in the method of FIG. 1 for printing a waterslide decal.

[0028] FIG. 4 shows an image information obtained by photogrammetric analysis of a base object, as used in the method of FIG. 3.

[0029] FIG. 5 shows a UV mapped image of the image information of FIG. 4.

[0030] FIG. 6 shows a plurality of waterslide decal specifications based on the UV mapped image of FIG. 5.

[0031] FIG. 7 shows a flow chart of a method of applying the waterslide decal of FIG. 2 to an object surface. DETAILED DESCRIPTION

[0032] According to a preferred embodiment of the invention, as shown in FIG. 1, a waterslide decal 100 depicting an image is produced, starting at step S 101 , by screen printing an adhesive bottom layer 110. The adhesive bottom layer 110 is adapted to adhere to an object surface of an object 10 to be decorated using the decal 100. In the preferred embodiment, the object 10 is a kitchen appliance, for example a juicer, as shown in FIG. 4. The method continues, at step SI 03 by screen printing one or more white layers 120 on the adhesive layer 110. The white layers 120 improve the colour-reproduction of the decal 100. The white layers 120 may not be required if the object 10 has a surface colour that is light coloured and/or white.

[0033] The method continues, at step S105, by printing one or more colour layers 130 on the white layer 120. The printing of colour layers 130 can be performed by one or more of the following steps S107, S109, Si l l. At step S107, one or more monochrome colour layers 132 are screen printed on the white layer 120. At step S109, one or more spot colour layers 134 are offset printed on the white layer 120, or the monochrome colour layer 132 if it was printed. At step Si l l, one or more CMYK colour layers 136 (being a layer of a shade of cyan, magenta, yellow, or black) are offset printed on the white layer 120, or the monochrome colour layer 132 if it was printed, or the spot colour layer 134 if it was printed.

[0034] The method then continues at step SI 13 by screen printing one or more transparent texture layers 140 on the last colour layer 130. The texture layers 140 provide 3D surface features to the decal 100 by elevating some portions of the decal 100 over other portions of the decal 100. This can be used to create or recreate physical effects such as brushstrokes, vellum/leather texture, and/or paint thickness. The method concludes at step SI 15 by screen printing a removable film 150 on the last texture layer 140. The decal 100, as shown in FIG. 2, is now ready to be applied to the object 10.

[0035] Before discussing the application of the decal 100 to the object 10, the method, shown in FIG. 3, of producing a decal specification to be followed by the method of steps S101 to S115 of printing the decal 100. The method of FIG. 3 commences, at step S201 by preparing an image information by photogrammetric analysis of the base object 10. Photogrammetric analysis is a known technique for accurately recording 2D and 3D features of an object in a digital format, usually be laser scanning, or a variety of optical scanning techniques that obtain both 2D and 3D information about the object 10. Thus, the image information has 2D information relating to 2D features of the object 10 and 3D information relating to 3D features of the object. An example of the image information obtained by photogrammetric analysis is shown in FIG. 4.

[0036] The method then preferably continues, at step S203, by modifying the image information to add lighting features to the 2D information based on the 3D information. This step modifies the 2D information based on the 3D information. For example, portions of the image that are recessed, may have their lightness reduced, while portions of the image that are embossed may have their lightness increased. This is achieved, for example by rendering the 3D information as an object in a 3D space, with the 2D information applied as a texture to the object. A light source is added to the 3D space and rendering software is used to determine the effect of the light source on the texture of the 3D object. This effect is then applied permanently to the 2D information of the image information. This results in a 3D effect of the 2D information, that is enhanced when the transparent layers 140 are printed on top of the 2D information to recreate the original 3D features of the object 10. At step S205, the image information is optionally further modified to match a colour information of the 2D information to one or more of the colour layers 130. Since the colour of the decal 100 is provided by discrete colour layers 130, each having a single shade, it is preferable for the colours in the 2D information to be rectified by being matched to one of the colours of the discrete colour layers 130, so that the colour reproduction is more vivid. Small chromatic divergences from the discrete colour layers 130 are then reproduced using the CMYK layers 136. It is therefore preferable to match the monochrome colour layers 132 to a predominant colour of the image, such that major portions of the image may be reproduced by the monochrome colour layers 132, rather than the CMYK layers 136. This process includes producing proofs of the 2D information and comparing the proofs against the base object 10. The 2D information of the image information may then be adjusted to account for the effect of the printing process on the accurate colour reproduction.

[0037] At step S207, a UV mapped image is prepared, as shown in FIG. 5, by UV mapping of the image information of FIG. 4. UV mapping is a known technique for mapping the coordinate system on the surface of an object to a planar coordinate system. As shown in FIG. 6, the UV mapped image is then divided into one or more waterslide decal specifications. Each waterslide decal specification has 2D specification relating to the 2D information for the steps SI 03, SI 05 of printing the white layer 120 and colour layers 130. Each waterslide decal specification also has 3D specification relating to the 3D information for the step SI 13 of printing the one or more transparent texture layers 140. [0038] Moving now to FIG. 7, which shows the preferred method of applying the decal 100 to the object 10. The method commences at step S301 by cleaning the object surface with 2- Butoxy ethanol, to avoid dust and grime interfering with the application process. At step S303 a paint basecoat is applied. The paint basecoat may be an enamel paint, a metallic paint, or a plastic paint. The base paintcoat is then dried for 30 to 40 minutes at a temperature between 65 °C - 130 °C. For metallic paint, the temperature is preferably between 120 °C - 130 °C, while for plastic paint the temperature is preferably between 65 °C - 75 °C.

[0039] At step S305, a polyurethane basecoat is applied to the surface of the object 10 to improve adhesion between the object surface and the decal 100. At step S307, the polyurethane basecoat is dried for between 30 to 40 minutes at a temperature between 65 °C - 75 °C. Meanwhile, at step S309, the decal 100 is soaked in a water bath having a water surface, such that the decal separates from a substrate onto which the decal 100 was printed. Preferably, the decal 100 is soaked for 10 to 120 minutes at a temperature between 20 °C - 30 °C to hydrate the decal 100.

[0040] At step S311, the hydrated decal 100 is transferred to the object surface, by removing the decal from the water bath and sliding the decal 100 onto the object surface. While the decal 100 remains hydrated, it is moveable with respect to the object surface, and can be aligned with other decals on the object surface. At step S313, the decal 100 is dried for 35 to 65 minutes at a temperature between 70 °C - 160 °C. Finally, at step S315, a polyurethane topcoat is applied to the object surface to improve survivability of the decal 100 on the object surface. At step S317, the polyurethane topcoat is dried between 30 to 40 minutes at a temperature between 65 °C - 75 °C.

[0041] Advantages of decal 100, its production, and application to object 10 will now be discussed.

[0042] Due to the use of transparent layers 140, 3D features such as brushstrokes or texture can be produced using a 2D printing method such as offset and/or screen printing, and transferred to the object 10 using the waterslide decal 100.

[0043] The use of monochrome colour layers 132 allows the vivid reproduction of key colours. Modifying the image information to match the colours of the monochrome colour layers 132 improves the vivid reproduction of those colours. The use of spot colour layers 134 allows the selective further reproduction of key secondary colours, similar to the use of monochrome colour layers 132. The use of CMYK colour layers 136 allows the reproduction of the remainder of the chromatic colour space that is not covered by the monochromatic colour layers 132 and the spot colour layers 134.

[0044] The preparation of waterslide decal specifications from UV images the includes 3D information and 2D information allows the printing of the transparent layers 140 to create the 3D features represented by the 3D information. The modification of the 2D information based on the 3D information prior to printing allows a more vivid reproduction of 3D features by altering lighting values based on the 3D information.

[0045] The use of a polyurethane topcoat on the object 10 after application of the waterslide decal 100 improves the ability of the object surface to withstand wear & tear, and also allows the surface to pass key regulatory requirements for kitchen appliances, such as chemical, mechanical, and electrical resistivity. The use of a polyurethane basecoat improves the adhesion of the decal 100 to the object 10. The cleaning of the surface using 2 -Butoxy ethanol further improves the adhesion of the decal 100 to the object 10. The various steps of drying layers and the decal 100 have been experimentally determined to provide optimal adhesion between the layers, while reducing the risk of damage to a layer due to excessive heat.

[0046] Integers:

10 Kitchen appliance / base object

100 Decal

110 Adhesive bottom layer

120 White layer

130 Colour layer

132 monochrome colour layer

134 spot colour layer

136 CMYK colour layer

140 transparent texture layer

150 Removable film