Patent Application
20070295448
My invention provides a way of manufacturing laminated articles having printed patterns fabricated using frangible materials such as very thin friable metal leafs on almost any kind of substrate. Referring now to
As shown in step 20, an image is transferred onto a substrate, by any of a large number of well-known printing methods (contact or non contact). As shown in step 22, the image is then preferably allowed to dry, depending on the application, substrate, and ink until it is partially cured but still retains a substantial amount of tackiness, although the image may be allowed to fully dry if sufficient heat and pressure are later used to the reactivate adhesive components in the ink (e.g. soften resins and restore tackiness). As further shown in step 24, the image is covered with a thin metal film or leaf comprising a frangible material. As shown in step 26, the image and leaf are then laminated by the application of pressure and heat. As finally shown in step 28, the resulting laminated image and substrate are gently scrubbed by some mechanical method to remove the excess frangible material such as rotating or moving brushes, sponges or fluid flow provided by compressed air or water jets or vacuum pressure.
Referring now to
The system 10 eliminates the need to use cutting tools to form or remove excess material, increases printing speeds compared to current methods such as electro-deposition of leaf or leaf like materials, and expands the types of substrates that leafs can be combined with.
Inks containing pigments and waxes, once dry, generally cannot be laminated with frangible leafs unless they are modified to contain adhesive components. This is because they contain a discontinuous resin film. However, inks based on dyes and without waxes can be softened, even if totally dry, by heating, and can bond continuously to frangible or flake-able materials. Laminating the printed image and leaf together at elevated temperatures and under pressure has the added advantage that frangible material not in contact with the image expands (along with the moisture present in paper and in air). Because the material cannot move sideways, this expansion causes it to move upwards, making the material flake off more easily. Further, after cooling, the laminated substrate and frangible material shrink together and reduce the size of any pinholes.
The substrate can be: any solid material (absorbent or non-absorbent) that can be exposed to direct or indirect pressure, heat or pressure and heat. The pressure applied will be in the general range 1 to 7 bar and is preferably applied for in general under a second. The heat the substrate will be exposed to should not exceed 450 Kelvin in general and will again be applied for under a second in most circumstances. Examples of possible substrates range from paper sheets as thin as airmail paper to as heavy as foam board, plastic sheets, metal sheets, food items (such as fruit), wood, stone (even marble or granite), etc.
The printing method can be: any mechanical way of printing (including non-contact) such as letterpress, planographic, flexographic, graveure, silk-screen, ink-jet, laser, or other equivalent printing methods.
The ink can be: an appropriate ink depending on the printing method and substrate used, however, inks containing substantial amounts of resinous materials or specially added adhesive components are preferred that provide sufficient tackiness for the leaf to quickly bond with the ink and substrate. Alternatively, special lamination inks containing components providing adhesive properties may be employed. Many resin based inks having conventional formulations have adequate adhesive properties.
The leaf can be: any of a number of frangible materials that are generally very thin such as metal leaf (preferably in the range of >0.21 μm but <8 μm). Leaf materials other than metals or metal alloys may be employed although very thin metal leaf made out of gold, silver, copper, palladium, or aluminum are preferred. For example, a 0.4 μm silver leaf is highly suitable. Other suitable leafs may include compositions including non-metallic materials that do not flake well at room temperature, but will flake away from substrates at lower temperatures.
The pressure can be: the pressure of the lamination will broadly vary depending on the specific application, ink, leaf, and substrate, but will generally use pressures in the range of those currently employed by commercially available lamination equipment, typically 1 to 7 bar.
The temperature can be: the temperature of the lamination will vary depending on specific application, but will be close to Ring and Ball softening point of the resin used in the ink or glue or for most such cases approximately 450 Kelvin.
The drying time can be: depending upon the substrate, ink, leaf, degree of the bond required and the thicknesses of the materials, the laminating time will range from a fraction of a second to more than 10 seconds.
This application claims the benefit of and priority from U.S. Provisional Patent Application 60/815,936 filed Jun. 23, 2006, which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60815936 | Jun 2006 | US |
