Patent Application
20080044600
The disclosed subject matter will now be described in more detail with reference to exemplary embodiments of the method and coated vehicle structure, given only by way of example, and with reference to the accompanying drawings, in which:
The disclosed subject matter relates to a film, such as a physical vapor deposition (PVD) film, having a decorative appearance and that is applied to a substrate, and its method of application.
The term “substrate” refers to a single layer or multilayer component wherein the surface of said substrate is prepared by conventional means known in the art, so that the substrate will readily accept the application of a thin layer thereon. For example, various materials can be applied to the top of the substrate to prepare the substrate for receipt of the metallic film, e.g., adhesive base coats, base materials, adhesion promoters, tie layers, etc. Furthermore, the disclosed subject matter relates to a method of producing three-dimensional effect designs on the substrate.
In this application, the term “element” is used to describe the multilayer component produced by the method of the disclosed subject matter. As illustrated in
In the first layer 1, the substrate can be flexible, semi-flexible or rigid, and its shape can be formed using any of a plurality of conventional molding or extrusion processes. For example, the first layer 1 can be made by a conventional coating method such as those disclosed in U.S. Pat. Nos. 5,837,354 and 4,551,387. The second layer 2 may be a thin metal film or a paint that matches that of the body part or other structure that is being coated. This layer 2 can be deposited by a metallizing method such as vacuum metallization or vacuum deposition. As disclosed in U.S. Patent Publication No. 2003/0037443 A1, vacuum deposition is a term applied to processes that deposit atoms or molecules one at a time, such as physical vapor deposition (PVD) or low pressure chemical vapor deposition (LPCVD), which are all contemplated for use with the disclosed subject matter. Various types of PVD are known in the art, including vacuum evaporation, sputter deposition or sputtering. Physical vapor deposition methods are clean, dry vacuum deposition methods in which the coating is deposited over the entire object simultaneously, rather than in localized areas. Reactive PVD hard coating processes combine a method for depositing the metal, in combination with an active gas, such as nitrogen, oxygen, or methane, and plasma bombardment of the substrate to ensure a dense, hard coating. The primary PVD methods are ion plating, ion implantation, and sputtering.
The third layer 3 can be a radiation curable formulation that is applied on top of the second layer 2. This layer 3 can be a hardened substance that provides a tactile three-dimensional pattern to the structure.
In an embodiment of the disclosed subject matter, the metallizing technique is by PVD. A sputtering process can be used to cover the first layer 1 with a thin metal layer 2 or sheet that provides a metallic appearance on the first layer 1. Furthermore, the thin metallic coating can be of a sufficient thickness to impart a reflective metal-like appearance to the element, or to provide a wood grain appearance, or other various appearances. Also, the thin metallic coating can be any size range, and possibly from 0 to 50 μm in thickness with 40 μm being well suited for vehicle applications. The thin metallic layer can include a metal such as chrome, satin nickel, aluminum, stainless steel, copper, bronze, silver, gold, etc.
In another embodiment of the disclosed subject matter, the radiation curable formulation for layer 3 is an ultraviolet light curing ink (UV ink). The UV inks are well suited for use in this embodiment because no solvents are released and the viscosity is not altered when exposed to the UV light source. Also, UV ink is particularly formulated to cure and dry when exposed to a UV light source. Furthermore, when UV ink is exposed to an ultraviolet light, the ink molecules polymerize into a hard ink film. Another advantage of using UV ink is that the drying time is very short.
The UV ink is applied onto layer 3 via any well known process, such as spraying, silk-screening, etc. After exposure to the UV light source, the ink polymerizes and forms a plurality of dots that can take the form of many various shapes and patterns. The plurality of dots from the spraying/silk-screening and subsequent hardening of the UV ink provide the element with a 3-dimensional tactile texture. The plurality of dots influences how the light is reflected, which affects the final decorative and three-dimensional appearance. Thus, the arranged pattern may be manipulated to achieve the desired appearance on the substrate. The plurality of dots can occupy any amount of surface area as determined by design requirements. The shape of the dots can vary widely, including elongate wood simulation patterns, circles, squares, other geometric shapes, brail, indicia, logos, etc.
Thus, when an element such as a trim piece for an automobile is coated by the decorative coating process, a decorative and three-dimensional tactile appearance can be produced. This not only provides an improved visual appearance, it also helps in hiding defects, such as surface defects, on different elements.
The real metallic print layer 22 can be applied by PVD or other known coating/attachment method, and can be anywhere from 200-600 Angstroms in thickness. The UV hardened ink 23 can be 40 μm thick, while the PC/ABS substrate 21 can be 2 mm thick and the film 20 can be a total of approximately 1 mm thick. The ABS tie layer 24 can be provided under the PMMA layer 25 to assist attachment of the film 20 to the PC/ABS substrate 21. The PMMA layer 25 can be a clear layer that contains UV additives and generally serves as a protective layer to prevent scratching or deterioration of the film and other component materials.
It is contemplated that other materials can be used for the various film and substrate layers. For example, the PC/ABS substrate 21 can be replaced with an ABS substrate, or other known substrate. One alternative embodiment can include a polypropylene tie layer in place of the ABS tie layer 24, and a polypropylene substrate instead of the PC/ABS substrate 21. The real metallic layer 22 can also be replaced with a pigment layer to create the wood grain design, as described above, or to form other decorative appearances for the film 20. If desired, one could place the UV hardened ink on top of the wood grain pigment layer to provide a true feel of wood grain with knots, etc.
a-4f show an example of a manufacturing method for applying a coating to a substrate in accordance with principles of the disclosed subject matter. In
Typically a vacuum forming process is used in the method of forming the film 30 onto the mold 102 such that the film is “pulled down” onto the shape of the mold 102. However, if the geometry of the final film form is more complicated or intricate, then pressure forming is commonly used. For example, vacuum forming is often used when forming a film onto a substrate that is to be used on a vehicle cup holder, a vehicle shifter escutcheon, and other uncomplicated structures. However, pressure forming is usually used to form a film for a vehicle audio panel and other similarly complicated structures in a vehicle.
It should be noted that injection molding, as shown in
There are two main categories of UV hardenable ink that can be used in conjunction with the disclosed subject matter. The first is hard UV ink that is commonly used in vehicle substrate surface applications. The other type is stretchable UV inks. Stretchable UV inks provide more visual effect options, and better effect quality, but do not provide the amount of three dimensional texture as provided by hard UV inks.
It is conceivable that both hard UV inks and stretchable UV inks can be used to manufacture a vehicle surface substrate in accordance with principles of the disclosed subject matter. For example, a stretchable UV ink can be screened onto a PMMA layer to provide an intricate graphic design. Then, a second PMMA layer (or other protective layer) could be applied on top of the stretchable UV ink, and a hard UV ink applied on top of that second protective PMMA layer. The hard UV ink would provide the tactile feature to the vehicle substrate surface while the stretchable UV ink provides the more intricate design/colorations.
While the disclosed subject matter has been described in detail with reference to exemplary embodiments thereof, it will be apparent to one skilled in the art that various changes can be made, and equivalents employed, without departing from the scope of the invention. Each of the documents referenced above is hereby incorporated by reference in its entirety.
