Patent Application
20190337304
The present invention is directed to apparatuses and methods for applying a transfer material onto an article, including apparatuses and methods of transfer printing onto and/or decorating three-dimensional articles, as well as the articles having the transfer material thereon and/or which are decorated thereby.
Various apparatuses and methods of printing are disclosed in the patent literature and on the internet. Patent publications disclosing apparatuses and methods of printing include: U.S. Pat. No. 6,135,654, Jennel; U.S. Pat. No. 6,699,352 B2, Sawatsky; U.S. Pat. No. 6,920,822 B2, Finan; U.S. Pat. No. 7,210,408 B2, Uptergrove; U.S. Pat. No. 7,373,878 B2, Finan; U.S. Pat. No. 7,467,847 B2, Baxter, et al.; U.S. Pat. No. 8,522,989 B2, Uptergrove; U.S. Pat. No. 8,579,402 B2, Uptergrove; U.S. Pat. No. 8,667,895 B2, Gerigk, et al.; U.S. Pat. No. 8,714,731 B2, Leung. et al.; U.S. Pat. No. 8,899,739 B2, Ohnishi; U.S. Pat. No. 8,919,247 B2; Mogavi, et al.; U.S. Pat. No. 9,303,185 B2, Sambhy, et al.; U.S. Pat. No. 9,487,027, Strater, Jr., et al.; and US Patent Application Publication Nos. US 2009/0207198 A1, Muraoka; US 2010/0212821 A1, Grinberg, et al.; US 2011/0232514 A1, Putzer, et al.; US 2013/0019566 A1, Schach; US 2014/0285600 A1, Domeier, et al.; US 2015/0022602 A1, Landa, et al.; US 2015/0024648 A1, Landa, et al.; US 2015/0183544 A1, Moffatt, et al.; and EP 1163156 B1, Johnson. Other types of apparatuses and methods include the apparatus and method disclosed in U.S. Patent Application Pub No. US 2012/0031548 A1, “Apparatus and Method for Applying a Label to a Non-Ruled Surface”, filed in the name of Broad.
A number of current efforts are being directed to printing, particularly inkjet printing, on three-dimensional articles such as bottles and the like. Some current printing apparatuses and processes use ink jet printing to print directly on three-dimensional articles. Unfortunately, with current inkjet technology and current printing apparatuses, the quality of labels that can be formed by printing directly on three-dimensional articles is not as good as that formed on separately printed flat labels. Further, such printing processes may only be able to accurately jet ink short distances (e.g., several millimeters) from the print head. Therefore, if the article has surface features that differ in height or depth by more than such short distances, the ink jetted by an ink jet print head will not be accurately applied, leading to defects in print quality.
For example, U.S. Pat. No. 7,891,799, Edwards, et al. (Electronics for Imaging, Inc.) discusses direct printing on an article where the print-layer deposited on the article comprises multiple layers. These layers include a reflective layer as well as a protective layer to prevent damage to the ink layer during shipment or use. These layers also include a base-coat that can be used to provide a smooth surface underlying the reflective layer, which can be necessitated if the article has a rough or irregular surface. Reflective layers can be highly desirable as decoration, particularly for premium products. Particularly desirable reflective layers will have high specular reflectance versus diffuse reflectance. Specular reflectance provides a mirror-like quality and generally requires not only a reflective medium but also a smooth surface of the reflective medium. Ensuring a smooth surface on the reflective layer in order to achieve high specular reflectance can be difficult with direct object printing.
Other processes for applying ink to three-dimensional articles are transfer processes. In these processes, ink is first applied to a transfer surface, and then the image is transferred from the transfer surface to the article. Current transfer processes may suffer from the disadvantage that they are not well suited to transfer the image from the transfer surface to articles with complex three-dimensional shapes and/or which have surface features that differ in height (or depth) by more than a limited extent.
In addition, if such transfer processes utilize energy curable adhesives to adhere the image to the surface of the article, difficulties arise when attempting to cure such adhesives. In the case of UV curable adhesives, it is often necessary to pass UV energy through several layers of ink that form the image. This can make it difficult to cure the UV adhesive.
A need exists for improved apparatuses and transfer methods for applying a transfer material, such as printing, decorations, or other substances onto three-dimensional articles, including transfer materials that incorporate reflective layers with relatively high specular reflectance.
The present invention is directed to apparatuses and methods for applying a transfer material comprising a reflective layer onto the surface of an article, including apparatuses and methods (or processes) of transfer printing onto and/or decorating three-dimensional articles, as well as the articles having the transfer material thereon and/or which are decorated thereby.
In some cases, the processes comprise:
In some cases, the transfer component may be continuous. In other cases, the transfer component may be a discrete element (that is, non-continuous). There can be variations in the step of modifying the portion of the transfer component with the transfer material thereon. In some cases, the portion of the transfer component that is modified may have two surfaces, both of which are deformed (e.g., deflected) during the modification step. The portion of the transfer component with the transfer material thereon may be modified in various different sequences relative to contacting the article (or being contacted by the article), including: prior to contact with the article; simultaneously to contact with the article; after initial contact with the article; and, combinations thereof. Several different types of mechanisms can be used to modify the transfer component. These include, but are not limited to: (1) conforming components with a cavity therein; (2) mechanisms in which a portion of the transfer component spans between spaced apart constraining components that constrain the transfer component in one or more directions, and the article is pushed into the span of the transfer component (or the span of the transfer component is pulled onto the article); (3) embodiments in which the transfer component may be brought into contact with the surface of the article by passing the transfer component through a nip that is formed by the surface of the article and a shaped die; and, (4) embodiments which use vacuum, air jets, fluid jets, and the like, or combinations thereof, to bring the transfer component into contact with, or in closer contact with, the surface of the article.
In some cases, the three-dimensional article has a surface comprising two or more portions that each have a different radius of curvature. These two or more portions may comprise a first portion having a first radius of curvature and a second portion having a second radius of curvature, wherein the second radius of curvature is less than the first radius of curvature. In such cases, it may be desirable for contact between the transfer component with the transfer material thereon and the surface of the article to initially occur at the second portion of the article with the lesser radius of curvature (such that it serves an “initial contact portion”), and then at the first portion of the article to assist and/or improve the process of conforming the transfer material to the surface of the article.
The apparatus for carrying out the process may comprise one or more functional devices at one or more stations for performing a function. The function(s) can be performed on the articles directly, or on the transfer component to create the transfer material that is transferred to the surface of the articles. The functional devices may include, but are not limited to: one or more deposition devices; adhesive deposition devices; devices for treating articles (e.g., devices for treating the surface of articles, or for curing substances applied to the articles); devices for decorating articles (e.g., application of a metal foil); devices for transforming a property of an article (e.g., laser); or combinations thereof. Some of the functional devices described above may be optional.
In some embodiments, the deposition device may comprise a printer such as an inkjet printer having an inkjet print head. If there are multiple deposition devices, one or more can comprise inkjet printers and other deposition device(s) can comprise other types of deposition devices. Alternatively, all of the deposition devices can comprise inkjet printers. In some cases, the transfer material may comprise an energy curable ink and/or adhesive. In some cases, the transfer material may comprise an aqueous ink. In some cases, the aqueous ink may comprise metallic particles. The metallic particles may comprise nanoparticles. When the transfer material is energy curable, the transfer component may be at least partially or substantially permeable to the curing radiation to allow curing of the ink and/or adhesive therethrough. The energy curable adhesive may be colored (such as with white pigment). In all of such cases, the process may further comprise providing a source of radiation, wherein said source of radiation is positioned so that the transfer component is disposed between the source of radiation and the energy curable composition, and at least partially curing the energy curable composition with the source of radiation through the transfer component. In such embodiments, the curing can take place during the time period between when the article and the transfer material make contact up until the transfer material is transferred from the transfer component onto the surface of the article. The curing radiation may be electromagnetic radiation that may include visible radiation (e.g. from a Xenon-flash source radiation, such as for sintering metallic ink) and/or UV radiation and/or high-energy radiation such as x-ray radiation of gamma-ray radiation. The curing radiation may be beta-radiation (e.g. electron beam radiation). The steps of the processes described herein can take place in any suitable order.
The articles having the transfer material thereon and/or which are decorated by the processes can comprise any suitable three-dimensional articles. In some cases, the articles may be plastic containers comprising a hollow container having an interior, an exterior surface, a top portion, a bottom portion, a front, a back, and sides. (Any description relating to the container herein may also apply to other types of articles.) The hollow container may be pre-formed in that it is formed prior to applying the transfer material thereto.
The exterior surface may comprise two or more portions that each have a radius of curvature. At least two of the two or more portions may be at least partially separated by an intermediate portion that has a lesser radius of curvature than the two portions. In some cases, at least two of the top portion, bottom portion, front, back, and sides of the article may have different configurations.
The transfer material may be applied onto and positioned on top of at least a portion of the surface of the article without penetrating into its surface. The transfer material may extend continuously across at least parts of said two portions and the intermediate portion. The transfer material may be pre-formed (such as with ink cured as in the case of curable inks and/or dried, as in the case of aqueous inks) and transferred to the desired portion(s) (such as the two portions and the intermediate portion) of the surface of the article. In some cases, at least two or more portions and the intermediate portion are all located on one of the top portion, bottom portion, front, back, or a side of the container, and the intermediate portion is a feature on said exterior surface that has a lesser radius of curvature than the two or more portions. The feature may protrude outward from the exterior surface. Alternatively, the feature may be recessed into the exterior surface. In other cases, the at least two or more portions are located on different portions or locations on the surface including the top portion, a bottom portion, a front, a back, and sides of the container, and the intermediate portion comprises an edge between the two or more portions.
In one non-limiting example, the transfer material may wrap around at least a portion (or all) of the front and/or back of the article and at least a portion of at least one of the sides and/or the bottom portion of the article. This can provide a transfer material that wraps at least a portion of two or more sides of the article (that is, a multi-sided wrap). In some cases, the transfer material may wrap around at least a portion (or all) of the front and/or back of the article and only a portion of at least one of the sides and/or the bottom portion of the article. In some cases, the transfer material may wrap around at least a portion (or all) of the front and/or back of the article and all of at least one of the sides and/or the bottom portion of the article. In such embodiments, this can provide the transfer material with a cleaner appearance without the visible edges typically seen on the front or back of articles which have heat transfer labels applied thereto. The transfer material can be transferred without a carrier remaining on the article after transfer material is applied to the surface of the article such as in the case of labels.
In some cases, the transfer material may be continuous across any of the front, back, sides or bottom portion of the article and a closure or cap. In one aspect, the transfer material may include a break at the interface of the article and the closure so as not to be damaged during the removal of the closure.
Any of the embodiments described in this specification may be combined, or provided with any of the features of any other embodiment described herein in any suitable combinations. All percentages of ingredients in the compositions described throughout this specification are by weight, unless otherwise specified. The terms “standard conditions” or “standard temperature”, as used herein, refer to a temperature of 77° F. (25° C.) and 50% relative humidity.
The embodiments of the method, apparatus(es), and articles shown in the drawings are illustrative in nature and are not intended to be limiting of the invention defined by the claims. Moreover, the features of the invention will be more fully apparent and understood in view of the detailed description.
The present invention is directed to apparatuses and methods for applying a transfer material comprising a reflective layer onto the surface of an article, including apparatuses and methods of transfer printing onto and/or decorating three-dimensional articles, as well as the articles having the transfer material thereon and/or are decorated thereby. The term “process” may be used herein interchangeably with the term “method”.
The term “transfer material”, as used herein, will be used to describe the material that is transferred from the transfer component to the surface of the article. This term is inclusive of a material alone, or a combination of a material, any adhesive thereon, or other material(s) joined thereto that will be transferred to the surface of the article. If the transfer material comprises a combination of materials, it may be referred to herein as the “composite transfer structure”. The term “substance” may be used interchangeably with the term “material” herein with reference to the material(s) that are deposited on the transfer component (and which will form all or part of the transfer material). Typically, a discrete or separate transfer material will be transferred to each article 10.
Numerous variations of the order of steps of these processes, as well as mechanisms to carry out the processes, are possible. The order in which the steps take place can be varied, and/or the steps and/or portions of the different processes may be combined in any suitable manner. In addition, any other suitable steps could be added to any of these processes. Suitable additional steps include, but are not limited to: applying a release coating to the transfer component prior to depositing a transfer material thereon; treating the surface of articles, or curing materials applied to the articles; decorating the articles; transforming a property of an article (e.g., by laser); or combinations thereof. In addition, if a reusable transfer component is used, the processes may further comprise a step of cleaning the transfer component after the releasing step. Such additional steps can be added, as appropriate, to either the front end and/or the back end of the processes of the categories shown in
As shown in
The apparatus 20 can be used to apply a transfer material 22 on numerous different types of three-dimensional articles 10. Such articles include, but are not limited to: containers or packages such as bottles, boxes, cans, and cartons; consumer products including, but not limited to pods, laundry dosing balls, razors; components of consumer products such as razor blade heads and handles; sprayer triggers; tubs; tubes including, but not limited to tampon tubes; and deodorant stick containers. The articles may include primary packages for consumer products, including disposable consumer products. Additional articles include components of containers or packages including, but are not limited to: bottle caps, closures, and bottle pre-forms that are subsequently blown into the form of a finished bottle.
The apparatus 20 can be used to apply material to empty containers, partially filled, or full containers including closed and open containers. The method and apparatus 20 can be used to apply material (e.g., decorate) the containers, the closures, or both (separately or simultaneously). The containers can have a rigid, flexi-resilient, or flexible structure in whole or in part. In some cases in which the articles are flexible and have an interior which is empty (such as in the case of some bottles), it may be desirable to blow air or other gas into the interior of the article in order to pressurize the article, above atmospheric pressure, so that the surface of the article does not yield excessively during the transfer process described herein. For example, at least a portion of the surface of the article to which a substance is to be applied is flexible, wherein the interior of the article, which is hollow or partially hollow, is pressurized prior to transferring the substance onto the surface of said article with the result that the portion of the surface of the article to which a substance is to be applied is less flexible while being pressurized. Containers such as bottles can be made by any suitable method including, but not limited to blow molding. Such containers may have a threaded opening, an opening configured to accept a snap-on closure, or any other suitable type of opening. The closures can be made by any suitable method including, but not limited to injection molding. Such containers may be capped or uncapped with a closure when the material is applied. In some embodiments, the material is applied to the container after the container is filled and has a closure applied thereto. In one exemplary process, the container is a blow molded container and the closure is an injection molded closure, and the container is filled with a fluent material and has the closure applied thereto. In such a process, the transfer material may be applied to the container and/or closure at the end of a bottling line.
The Articles
The articles can be made of any suitable material, including but not limited to: plastic, metal, and/or cardboard. If the articles are made of plastic, they can be made of any suitable plastic. Suitable plastics for bottles, for example, may include, but are not limited to: polypropylene, polyethylene terephthalate (PET), high density polyethylene (HDPE), and low density polyethylene (LDPE).
The articles 10 will typically have at least two opposing ends. For example, a bottle will have a base and a top. The articles 10 may also have a front, a back, and sides. The articles 10 will also have a surface 12. The articles 10 may be solid as in the case of some razor blade handles, or hollow or partially hollow in the case of bottles, for example. The surface of the articles 10 may be flat (planar) or curved. The entire surface need not be either flat or curved. For example, the surface of the articles 10 may have: portions that are flat; portions that are curved; or, the surface may have both flat portions and curved portions. For instance, in the case of bottles, at least a portion of the surface may have a convex curvature. It is also possible that some articles may have a surface in which at least a portion thereof has a concave curvature.
The articles 10 can be described using a coordinate system, as shown in
A lateral centerline CL2 runs parallel to the X-axis. As used herein, the term “lateral” refers to a direction, orientation, or measurement that is parallel to a lateral centerline of a container, when the container is standing upright on a horizontal support surface, as described herein. In the case of a container resting on a horizontal support surface S, a lateral orientation may also be referred to a “horizontal” orientation, and a lateral measurement may also be referred to as a “width.” As shown in
In some embodiments, it may be desirable that the method be used to apply the transfer material 22 to non-cylindrical three-dimensional articles, and thus on surfaces of articles that do not form part of a cylindrical object. In such cases, one or more of the front, back and sides may have different configurations. Such surfaces may as a result, be more complex (and difficult to apply transfer materials to) than cylindrical surfaces. In some embodiments, it may be desirable to apply a transfer material onto articles that have non-ruled surfaces. A non-ruled surface can be described as one that has a Gaussian curvature that is not equal to zero (e.g.,
In some embodiments, the method may be used to apply a transfer material onto the surface of articles that have complex curvatures in which the surface comprises regions with curves that have more than one radius of curvature. The surface of the article may also have more than one axis of curvature (aside from any changes in curvature such as that which are present on a cylindrical article where the curved sides of the cylinder transition into the top and bottom of the article). The terms “axis of curvature” or “axes of curvature”, as used herein, refer to an axis that passes through the center of a curve such as an arc or a circle (that is, the center point from which the radii of the curve extend) which is perpendicular (orthogonal) to the plane in which the radius of the curve is measured.
In some embodiments, the three-dimensional article has a surface comprising two or more portions that each have a different radius of curvature. These two or more portions may comprise a first portion having a first radius of curvature and a second portion having a second radius of curvature, wherein the second radius of curvature is less than the first radius of curvature. In such cases, it may be desirable for contact between the transfer component with the transfer material thereon and the surface of the article to initially occur at the second portion of the article with the lesser radius of curvature, and then at the first portion of the article. In such cases, it may be desirable for the radius of curvature of the second portion to be greater than zero. The first and second portions with the first and second radii of curvature, respectively, can be in any suitable location and orientation on the article. In some cases, the first and second portions are both located on one of the top portion, bottom portion, front, back, or a side of an article such as a container. The first and second portions may be adjacent, or spaced apart. In some cases, the first radius of curvature and the second radius of curvature may lie in a plane that is orthogonal to the longitudinal centerline of the article (e.g., and the Y axis of the article). In other cases, the first radius of curvature and the second radius of curvature may lie in a plane that is orthogonal to the lateral centerline of the article (e.g., and the X or Z axis of the article). The first and second portions can comprise portions of the surface of the article with any relative amounts of curvature. For example, in some cases, the second portion will typically have a radius of curvature that is less than the maximum radius of curvature of the surface. In other cases, the second portion can have a radius of curvature that is in the lowest 50% of all the radii of curvature on the surface. In still other cases, the second portion can have the lowest radius of curvature on the surface.
In some embodiments, the method may be used to apply a transfer material onto two or more portions of an article that each have a radius of curvature. At least two of the two or more portions may be at least partially separated by an intermediate portion that has a lesser radius of curvature than the two portions. (When it is said that the two or more portions may be “at least partially separated by” an intermediate portion, it is meant that the intermediate portion may extend the full length of the two or more portions and form a boundary therebetween; or, the intermediate portion may only extend a portion of the length between the two or more portions.) The two or more portions may have any suitable radius of curvature. The radius of curvature of the two or more portions may be the same as the other such portions, or different. Such radii of curvature of the two or more portions may range from a radius that is greater than that of the intermediate portion up to an infinite radius of curvature in the case of a flat portion of the exterior surface (or any range therebetween). Suitable radii of curvature for the intermediate portion are described below. In some cases, the two or more portions and the intermediate portion are all located on one of the top portion, bottom portion, front, back, or a side of an article such as a container, and the intermediate portion is a feature on said exterior surface that has a lesser radius of curvature than the two or more portions. The feature comprising the intermediate portion may protrude outward from the exterior surface of the article. Alternatively, the feature may be recessed into the exterior surface of the article. These features can have any suitable configurations. An example of a feature that protrudes outward from the exterior surface is protrusion or a ridge. An example of a feature that is recessed into the exterior surface is a groove or dimple. Non-limiting examples of an article having such features are shown in
In other cases, the at least two or more portions are located on different portions or locations on the surface including of the top portion, a bottom portion, a front, a back, and sides of the article, and the intermediate portion comprises an edge between the two or more portions. The apparatuses and methods described herein may, thus, be used to provide a transfer material which wraps around at least portions of two or more sides of an article (including but not limited to portions of three sides) to provide a multi-sided application of the transfer material. The transfer material may, thus, provide a continuous image on at least portions of two or more sides of an article wherein the sides of an article have a portion of the article therebetween (an intermediate portion or connector) that has a lesser radius of curvature than the portions of the sides of the article. This is shown schematically in
The Transfer Component
The transfer component 24 may be any suitable component that is capable of receiving one or more materials that are deposited on the transfer component 24 to form a transfer material 22 and then transferring the transfer material 22 to the surface of an article 10. The transfer component 24 can comprise one or more discrete components having the properties described herein wherein each discrete component receives a single transfer material deposit for application to a single article 10. In other cases, the transfer component 24 can comprise a continuous component. The term “continuous”, as used herein, refers to a transfer component that receives two or more transfer material deposits for application to different articles. Typically, a continuous transfer component 24 will be capable of receiving a plurality of transfer material deposits for application to different articles. A continuous transfer component 24 will typically have a machine direction length that is greater than the dimension of the article to which the transfer material 22 is to be transferred. Continuous transfer components can be in a number of different forms. For example, a continuous transfer component 24 can be in the form of a web that is unwound from a supply roll, and after use, rewound on a take-up roll. In other cases, the continuous transfer component 24 can be in the form of an endless (that is, a closed loop) belt.
The transfer component 24 may be a single use component such that once a transfer material 22 is transferred from the transfer component 24 to an article 10, the same portion of the transfer component that contained the transfer material is not used to transfer another transfer material to another article. In such a case, the transfer component 24 may be disposable after use, or recycled in an environmentally compatible manner. In other cases, the transfer component 24 may be reusable so that the same portion of the transfer component 24 may be used to receive and transfer more than one transfer material to different articles. When the transfer component 24 is reusable, it may be desirable to clean the transfer component 24 between the transfer of one transfer material 22 and the receipt of another transfer material 22 thereon. Therefore, the transfer component 24 may pass through a cleaning station after the transfer component 24 releases from the transfer material.
The transfer component 24 may have any suitable properties. The properties will often depend on the type of transfer component. For example, if the transfer component 24 is in the form of a pad or a roll, the transfer component 24 may have a surface, at least a portion of which is compressible so that it may conform to the surface of the article 10. In other cases, it may be desirable for the transfer component 24 to be substantially incompressible under the forces associated with carrying out the method described herein. If the transfer component 24 is in the form of a web or in the form of a belt, the web or belt will typically have two opposing surfaces that define a thickness therebetween. These surfaces may be referred to as a front or “transfer surface” 24A and a back surface 24B. In some cases, it may be desirable for the web or belt to be relatively thin and/or flexible so that it may conform to the surface 12 of the article 10 without the need to compress the surface of the transfer component 24 so that the thickness of the transfer component 24 changes substantially. In such a case, both surfaces 24A and 24B of the transfer component 24 may flex in a similar manner when the transfer component 24 and the article 10 are brought into contact with each other.
In some cases, a transfer component 24 in the form of a web or belt may have at least some portions that are unsupported (that is, span without any backing) between the transfer material receiving areas on the surface of the same. This characteristic of a transfer component 24 in the form of a web or belt is one of the ways such a web or belt transfer component is distinguishable from offset blankets that are mounted on cylinders.
The transfer component 24, whether discrete or continuous, may also be extensible in at least one direction. For example, the transfer component 24 may be extensible in one direction and in a direction perpendicular thereto in the plane of the surfaces of the transfer component 24. A continuous transfer component 24 that moves during the process will have a machine direction (MD) oriented in the direction of movement and a cross-machine direction (CD) perpendicular to the machine direction in the plane of the surfaces of the transfer component. The continuous transfer component 24 can be extensible in the machine direction and/or the cross-machine direction. In some cases, the transfer component 24 may be omni-direction extensible (extensible in all directions in the plane of the surfaces of the transfer component). In some cases, the transfer component 24 may be extensible in one direction, but due to the Poisson effect (for example), may contract in another direction (such as in a direction perpendicular to the direction in which it is extended) in the plane of the surfaces of the transfer component.
If the transfer component 24 is extensible, it may be extensible in any suitable amount under the forces associated with conforming the transfer component to the surface of the articles 10 during the process described herein. As shown, for example, in
In embodiments of the process that utilize an energy curable transfer material (decoration and/or adhesive), it is desirable that the transfer component 24 is at least partially or substantially permeable to the curing radiation. Typically, in order to be permeable to some forms of radiation (e.g. visible, UV), the transfer component will comprise at least some transparent or translucent portion(s). Any suitable level of permeability that permits some curing of the energy curable material is possible. When the transfer component 24 is described herein as being “permeable” to radiation, either one or more portions, or all of the transfer component 24 may be permeable to radiation. Typically, at least those portions of the transfer component 24 that have an energy curable transfer material deposited thereon will be permeable to the curing radiation. This will allow the curable transfer material to be cured by passing radiation through the permeable portions of the transfer component.
The transfer component 24 can be comprised of any suitable material. The material may depend on the type of transfer component, and whether it is desirable for the transfer component to be compressible or substantially incompressible. Suitable types of transfer components include, but are not limited to: films, belts, and discrete components. Some discrete transfer components can be comprised of film, and some can be comprised of a material similar to that used in belts. Film and discrete transfer components comprised of film may be made from materials that include, but are not limited to: polyethylene, polyester, polyethylene terephthalate (PET), and polypropylene. Belts and some discrete transfer components may be made from materials that include, but are not limited to: rubber, rubberized materials, polyurethanes, and felt. At least some of such materials may be low surface energy materials having a surface energy of less than or equal to about 45 dynes/cm. Some transfer components 24 made from films may be disposable. It may be desirable that some transfer components 24 in the form of belts may be reusable.
The transfer component 24 may be of any suitable thickness. If the transfer component 24 is in the form of a film, it may have a thickness that falls within a range that is greater than about 0.1 mil (0.0001 inch or about 0.0025 mm) to less than or equal to about 0.2 inch (about 5 mm), alternatively less than or equal to about 0.125 inch (about 3.2 mm), alternatively less than or equal to about 0.08 inch (about 2 mm), alternatively less than or equal to about 0.06 inch (about 1.5 mm), or any narrower range therebetween. A disposable film may, for example, have a thickness in the range of from about 0.0001 inch (about 0.0025 mm) to about 0.001 inch (about 0.025 mm). It may be desirable for the transfer component 24 to have a thickness at the lower end of the range when the article 10 has significant surface features such as high levels of localized curvature, so that the transfer component 24 is better able to conform to the configuration of the surface of the article 10. In addition, it may be desirable for the transfer component 24 to have a greater thickness within the aforementioned range if it is reusable, than if it is disposable. If the transfer component 24 is in the form of a durable belt, for example, it may have a thickness in the range of from about 0.01 inches (about 0.25 mm) to about 0.06 inches (about 1.5 mm). In other cases, it may be desirable for a durable belt to have a thickness greater than 1.5 mm to offer some compressibility.
In some cases, the transfer component 24 may have limited compressibility in a direction normal to its surfaces 24A and 24B (that is, in the direction of its thickness). For example, in some cases, the transfer component 24 may compresses less than or equal to about 50%, 40%, 30%, 20%, or 10% of its uncompressed thickness under 20 psi pneumatic pressure applied normal to the surface of the transfer component 24. In some cases, the transfer component 24 may also be substantially incompressible. The transfer component 24 may, for example, be substantially incompressible when it is in the form of a film. When it is said that the transfer component 24 is substantially incompressible, it is meant that the transfer component 24 compresses less than or equal to about 5% of its uncompressed thickness under 20 psi (138 kPa) pneumatic pressure applied normal to the surface of the transfer component 24. In some cases, the transfer component 24 may compress less than or equal to about 1% of its uncompressed thickness under 20 psi pneumatic pressure applied normal to the surface of the transfer component 24.
The surface 24A of the transfer component 24 should be capable of receiving a deposit of a material thereon. For instance, if the material first deposited on the transfer component 24 is printing, the surface 24A of the transfer component may be described as a “print-receiving” surface. If desired, the surface 24A of the transfer component 24 may have an optional release coating thereon to facilitate transfer of the transfer material 22 to the article. Suitable release coatings include, but are not limited to oils and waxes including silicone oils and waxes. The release coating will typically be applied to the transfer component 24 before any materials are deposited on the transfer component 24. The release coating will typically remain on the transfer component 24 and will not comprise part of the transfer material 22 that is transferred to the article 10.
The Deposition Devices
The material deposition devices (“deposition device(s)”) 26 can deposit any suitable material (or substance) on the transfer component 24. The apparatus 20 can comprise any suitable number, arrangement, and type of deposition device(s) 26. For example, the apparatus may comprise between 1-20, or more, deposition device(s) 26. Thus, there may be a plurality of deposition devices 26.
The deposition device 26 may, in some cases be part of the apparatus 20 and process for transferring the transfer material 22 onto the articles 10 as shown in
The deposition devices can either be of a type that contacts the transfer component 24 directly or by indirectly applying pressure to the transfer component 24 through the material (“contacting”), or of a type that does not contact the transfer component 24 (“non-contacting”). For the purposes of this disclosure, spraying ink on a transfer component is considered to be non-contacting. The component 25 for supporting the transfer component 24 during material deposition can comprise any type of component that is capable of serving such a purpose. The component 25 providing the support surface may include, but not be limited to: a cylinder, a belt, or a static plate (e.g., an arcuate plate).
The deposition device 26 can be any suitable type of device including, but not limited to: offset printing systems, screen printing systems, gravure printing systems, flexographic printing systems, print heads, electro-photographic systems, nozzles, and other types of material deposition devices. In the case of print heads, any suitable type of print heads can be used including, but not limited to piezo inkjet print heads, thermal inkjet print heads, electrostatic print heads, and/or printing valve print heads. The print heads may be a drop-on-demand type of deposition device. By “drop-on-demand”, it is meant that the print heads create droplets of ink at the nozzle only when needed such as to form a pattern in the form of words, figures or images (e.g., pictures), or designs. The print heads may also be “continuous” meaning drops are continuously formed at the nozzles, however only desired drops leave the print head to form the intended pattern. Ink jet print heads are typically digitally actuatable and can digitally print patterns provided by a computer. Thus, ink jet print heads are a form of a digital printing device that can digitally print material to produce the desired pattern on a portion of the transfer component 24.
Offset printing is a commonly used printing technique in which the inked image is transferred (or “offset”) from a plate to a rubber blanket, then to the printing surface. When used in combination with a lithographic process (in a litho offset process), which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film (called “fountain solution”), keeping the non-printing areas ink-free.
In the case of screen printing systems, any suitable screen printing system may be used. The screen printing system generally comprises an open mesh bearing a stencil. The stencil is the negative of the image to be created, and ink is then forced-through the open portions of the mesh (i.e., where the stencil is absent) to form the image. The image may be formed directly on the transfer materials and/or transfer component or formed on an intermediate and then transferred to the transfer material or transfer component. Screen printing systems generally print one color at a time, so a multi-color image would be created through the use of multiple inks and multiple screens.
In the case of gravure printing systems, any suitable gravure printing system may be used. The gravure system generally comprises creating a gravure plate on which the image to be deposited as part of the transfer material is formed as depressions (e.g. embossed or etched portions) within the gravure plate. Ink may then be filled into these depressions and transferred to the transfer materials and/or transfer component either directly, or by means of an intermediate such as a roller or belt. Transferring the ink from the depressions to the intermediate or to the transfer materials and/or transfer component may be facilitated by applying pressure to the gravure plate and/or by providing that the intermediate or transfer component by comprised of a flexible material. If a curable ink is used, the ink may be cured or partially cured prior to being transferred to the transfer materials and/or transfer component. In the case of flexographic printing systems, any suitable flexographic printing system may be used. The flexographic printing system generally comprise creating a flexographic plate on which the image to be deposited as part of the transfer material is formed “in relief” as raised portions on the flexographic plate. Ink may then be applied to these raised portions (e.g. via an ink roller) and then transferred to the transfer materials and/or transfer component via contact with the raised portions of the flexographic plate. If a curable ink is used, the ink may be cured or partially cured prior to being transferred to the transfer materials and/or transfer component.
In the case of electro-photographic systems, any suitable electro-photographic system may be used. The electro-photographic system generally comprises the following apparatus and/or steps. A photosensitive surface such as a photoconductor which is statically charged, as part of the process, for example by means of a corona discharge or other charging means. The charged photoconductor is then exposed to an image that is to be reproduced by the electro-photographic system. The image is reproduced on the charged photoconductor as regions of selective discharge imparted by the light that comprises the image. The image may be presented to the charged photoconductor “in negative”, meaning that the regions of light that impinge on the photoconductor eventually become the void regions in the transferred image. The image is then made visible, and transferable, by spreading a toner (e.g. a powder or a liquid toner), over the photosensitive surface, which adheres primarily to the charged areas. The image is then transferred directly to the transfer material and/or transfer component, or indirectly by first transferring the image to a transfer blanket/roller and then transferring the image from the transfer blanket/roller to the transfer material and/or the transfer component. The image may be further treated, by fusing the toner with pressure and heat at any point after the image is created.
Suitable materials or substances that may be deposited by the deposition device include, but are not limited to: inks (including energy-curable inks, water-based inks, and solvent-based inks), adhesives, varnishes, coatings, and lotions. Inks may comprise pigments such as conventional and/or effect pigments. Conventional pigments generally include absorption pigments that impart color and scattering pigments that impart whiteness. Effect pigments are those that are intended to impart visual effects other than color (e.g. reflectance, pearlescence, iridescence, luster, interference, color-shifting, diffraction, refraction). For example, the effect pigment may comprise metal particles for the purpose of providing specular reflectance. The material can be deposited in any suitable form. Suitable forms include, but are not limited to: liquids; colloids including gels, emulsions, foams and sols; pastes; powders; and hot melts (the latter being solids that may be heated to flow). The material can be deposited in any suitable pattern. Suitable patterns can be regular, irregular, or random, and include, but are not limited to: words (text), figures, images, designs, an indicium, a texture, a functional coating, and combinations thereof.
Ink jet print heads will typically comprise multiple nozzles. The nozzles are typically generally aligned in rows and are configured to jet ink in a particular direction that is generally parallel to that of the other nozzles. The nozzles within each row on a print head 26 can be aligned linearly. Alternatively, the nozzles may be arranged in one or more rows that are oriented diagonally relative to the longer dimension (or length) of the print head. Both such arrangements of nozzles can be considered to be aligned substantially linearly. The inkjet print heads can comprise any suitable number and arrangement of nozzles therein. The nozzles on the inkjet print heads can have any suitable opening diameter. Suitable opening diameters may range, for example, from about 10 μm to about 200 μm, alternatively from about 10 μm to about 50 μm. One suitable inkjet print head contains approximately 360 nozzles per inch (per 2.54 cm). The Xaar 1002 is an example of a suitable print head for use herein, and is available from Xaar of Cambridge, UK. A suitable hot melt inkjet print head is the Fuji Galaxy PH 256/30 HM.
The droplets of ink formed by an ink jet print head can range in diameter from about 10 microns or less to about 200 microns, or more. The droplets of ink can be distributed in any suitable number over a given area. Typically, in ink jet printing, the ink droplets form an array or matrix in which the number of drops per inch (2.54 cm) (DPI) is specified in the direction of movement of the print head or article to be printed, and in a direction on the surface of the article perpendicular thereto. (It will be appreciated that in the process described herein, such an array or matrix will be deposited on the transfer component 24, and then transferred to an at least a partially three-dimensional (e.g., curved, including in a convex or concave form) surface.) The application of ink drops provided on the surface of the article to form a digital image can range from about 200, or less up to about 2,880 or more drops per inch (DPI) in at least one direction. In some cases, the droplets of ink can be deposited in a matrix that ranges from 700 to 1,440 drops per inch in at least one direction. In some cases, the droplets of ink may be deposited in a matrix that is greater than 1,200 drops per inch up to about 2,880 or more drops per inch in at least one direction.
When the deposition device(s) 26 comprise print heads, one or more of the deposition devices 26 may comprise a printing unit (or “printing station”). The ink jet print heads may be configured to print ink (black, color, metallic), adhesives, or varnish (clear or colored). Each printing unit may comprise any suitable number of print heads, from one to four or more. For example, in some cases, the printing unit may comprise four print heads for a CMYK (cyan, magenta, yellow, and key (black)) color scheme for producing different color sets of a multicolor print. The printing unit may also comprise additional print head(s) for additional colors, e.g., white and/or special colors, for a priming coat or for a base layer, e.g., an adhesive, and/or for applying a transparent sealing or protective coating. As used herein, “special colors” may include optical effects. For example, inks comprising pigments designed to deliver different optical effects such as reflectance, pearlescence, iridescence, luster, interference, color-shifting, diffraction, refraction and the like may be used. In some embodiments, there may be multiple printing stations, such as one or more for an optional base coat, one or more for a decoration coat, one or more for an adhesive, and one or more for an optional top coat.
The ink may be a transparent ink, meaning that the resulting ink-layer has a degree of transparency. Relative to the ink-layer, the term “transparent” or to have a “degree of transparency” is taken to mean that any layers of the transfer material that are disposed immediately adjacent to the transparent ink layer are at least partially visible when viewed through the transparent ink layer. By contrast, and opaque ink-layer would be one in which the adjacent ink layer is not visible when viewed through the opaque ink layer.
The ink may be a “metallic ink”, meaning that it may comprise pigment particles that may comprise a metal such as silver, aluminum, gold, nickel, and/or copper. Metallic inks, when dried and/or cured can yield a reflective effect. This reflective effect can be greatly enhanced when the metallic ink layer has a smooth surface so that the specular reflectance is enhanced (e.g. versus diffuse reflectance). It is believed that one aspect in which reverse-printing an article with a metallic ink to form a reflective surface is advantageous versus direct printing is the ability to control the smoothness of the surface of the resulting reflective ink-layer. Specifically, when depositing the metallic ink onto the transfer component, or onto another layer previously deposited onto the transfer component, the surface-roughness of the metallic ink-layer will largely conform to the surface roughness of the transfer component and/or the previously applied material-layer. By using a smooth transfer component, then, a reflective layer with high specular reflectance (versus diffuse reflectance) can be created, regardless of the surface-roughness of the article itself.
As such, the transfer component may have a surface roughness within the desired range(s) of the surface roughness of the metallic ink layer. Likewise, the metallic ink layer may be deposited on a previously-deposited ink or varnish or adhesive or other layer that similarly has a surface roughness (on the side to which the metallic ink is deposited) within the desired range(s) of the surface roughness of the metallic ink layer.
The smoothness of the metallic ink layer can be measured as its surface roughness. Surface roughness is generally taken as the root mean square height of the surface irregularities. Surface roughness can be determined by Davies' expression, which relates surface-roughness (σ) and wavelength (λ) to the observed specular reflectance (Rs) as a function of a perfectly-smooth surface of the same material (Ro). For example, for a representative wavelength within the visible spectrum (i.e. λ=500 nm), a surface with a roughness, σ, of about 60 nm would yield a specular-reflectance efficiency (Rs/Ro) of about 10% while a surface with a roughness of about 33 nm would yield a specular-reflectance efficiency of about 50%. It would be understood that different metallic inks would have different Ro, as this property is a function of the material choices in formulating the metallic layer and/or the ink(s) comprising the metallic layer, so that Rs in the absolute would be a function of both the surface roughness (σ) and the material choice.
The metallic ink layer may have a root mean square (RMS) surface roughness of less-than about 2000 nm, 1500 nm, 1000 nm, 500 nm, preferably less than about 400 nm or less than about 300 nm, 200 nm, 150 nm, 120 nm, 100 nm, 60 nm, 50 nm, 40 nm, 30 nm, 20 nm, or 10 nm.
The RMS surface roughness of the metallic ink layer may be imparted to the ink layer by the material onto which the metallic ink layer is deposited. For example, if the metallic ink layer is deposited directly onto the transfer component, the metallic ink layer may have a surface roughness that is substantially equal to the surface roughness of the transfer component. Alternately, if the metallic ink layer is deposited onto a previously-deposited varnish or ink layer, the metallic ink layer may have a surface roughness that is substantially equal to the surface roughness of the surface of the ink or varnish layer onto which it was deposited. Table 1 details surface roughnesses of two representative transfer components and two representative varnish layers that were deposited onto the transfer components. The transfer component is a polyethylene film and the varnish is a cured acrylate-based varnish. Example 1 included a matte polyethylene film and Example 2 included a glossy polyethylene film.
Specular reflectance may also be enhanced versus diffuse reflectance by “filling in” the roughness of the metallic ink layer with an over-coat, such as a varnish or a transparent ink layer. The ability of the over-coat to enhance the specular reflectance will depend on the match (or mis-match) of the indices of refraction of the materials comprising the reflective layer and the over-coat layer. Preferably, the indices of refraction of these materials are identical, similar, or nearly similar.
It may also be desirable that the metal ink layer, or any ink layer whether or not it comprises metal-containing particles, spread-out upon being applied in order to form a coherent layer. For example, if the ink is applied by inkjet or other means that generally includes applying the ink in the form of a series of ink droplets, the individual ink droplets may spread upon application to a substrate to from a coherent layer. This spread may be characterized as the ink wetting the surface onto which it is applied. At the same time, however, it may be important that the ink not over-wet the surface onto which it is applied (e.g. either the transfer component or a previously applied ink or varnish layer); meaning that the ink should not spread beyond the intended area. This wetting may be controlled, at least in part, by adjusting the surface energy of the surface onto which the ink is applied (e.g. either the transfer component or a previously applied ink or varnish layer).
The ink layer, including metallic and non-metallic ink may be deposited on a previously-deposited varnish layer or ink layer. The previously-deposited varnish layer or ink layer may have a surface energy from about 50 mN/m to about 90 mN/m or from about 65 mN/m to about 90 mN/m or from about 70 mN/m to about 85 mN/m or from about 75 mN/m to about 80 mN/m, specifically reciting all 0.1 mN/m increments within the specified ranges and all ranges formed therein or thereby. The previously-deposited varnish layer or ink layer may have a surface energy greater than about 70 mN/m. The surface energy of the previously-deposited varnish layer or ink layer allows for the subsequently deposited ink layer, which may include metallic and non-metallic ink(s), to coalesce without over wetting. For example, when printing indicia, such as text, the individual characters of the text should remain legible. More specifically, when printing a letter “A” the individual components of the letter “A” should coalesce but not over wet. Over wetting could result in filling in unwanted portions outlined by the letter, such as the inner triangular portion of the letter “A”. It is to be appreciated that the surface energy may be changed based on application of materials, such as an ink layer and/or a varnish layer. Table 2 details surface energy of a representative transfer component and a transfer component including a previously-deposited varnish layer. The transfer component is a polyethylene film and the varnish is a cured acrylate-based varnish.
The metal-containing pigment particles may be of any size appropriate to yield the reflective layer. In some cases, the metal-containing pigment particles may have an average diameter of less than about 5 um, alternately 1 um. In some cases, the average diameter of the metal-containing pigment particles is less than about 500 nm, alternatively less than about 100 nm, or less than about 50 nm. The particles may, thus, be nanoparticles (particles with at least one dimension between 1 and 100 nanometers (nm)). The particle-size distribution of the metal-containing pigment particles may be highly mono-disperse. Mono-dispersity can be described on the basis of the particle size distribution (PSD) of the pigment particles. The PSD of a monodisperse pigment will include a large fraction of particles with a particle-size close to the mean (arithmetic average) of all particles measured. For example, a monodisperse particle size distribution may have greater than 90% of particles within 20% of the mean. In some cases, the PSD may have greater than 90% of particles within 15%, 10% or 5% of the mean. It would be understood by one of ordinary skill that the PSD may be taken over any appropriately sized sample of the ink or of the dried ink-layer. The mean of any sample of the metallic ink is the sample-mean.
The metal-containing pigment particles may be present in the ink composition at a level from about 1% to about 80%. The metal-containing pigment particles may be present in the ink composition at a level greater than about 2%, 5%, 10%, 20%, 30%, 40% or 50%. The metal-containing pigment particles may be present in the ink composition at a level less than about 80%, 70%, 60%, 50%, 40%, 30%, 20%, 10%, 5%, or 2%. Thus, in some cases, the metal-containing pigment particles may be present in the ink composition at a level of about 20%.
The metallic ink may be a UV ink, an aqueous ink, a solvent-based ink, or any other type of ink appropriate to the application. It is to be appreciated that these different ink types may have different wetting properties based, in part, on their polarity. For example, aqueous inks may be relatively polar and solvent-based inks may be relatively non-polar.
In one embodiment, the metallic ink is an aqueous ink. The metallic aqueous ink may comprise (in addition to water) solvents, humectants, and the like that are removed during drying, and do not ultimately comprise a substantial fraction of the resulting ink-layer. Preferred solvents or humectants include water-soluble materials. Further, to ensure that the solvents or humectants can be readily removed during drying, the solvents or humectants may have a boiling point that is less than about 250° C. and/or a molecular weight that is less than about 200 g/mol. Non-limiting examples of solvents or humectants that might be useful include alcohols, ethers, glycols, and glycol-ethers such as ethylene glycol, propylene glycol, dipropylene glycol. Also included are alkyl ethers of any of ethylene glycol, propylene glycol, dipropylene glycol including methyl ethers, ethyl ethers, isopropyl ethers, butyl ethers, isobutyl ethers. Also included are alcohols such as ethanol, propanol, isopropanol, butanol, 2-alkoxyethanol, 2-(2-butoxyethoxy) ethanol, and the like. Non-aqueous solvents or humectants may be present in the ink composition at a level from 0% (if none), or greater than 0% to about 40%. Non-aqueous solvents or humectants may be present in the ink composition at a level greater than or equal to about 5%, 10%, 20%, 30% or 40%. Non-aqueous solvents or humectants may be present in the ink composition at a level less than or equal to about 40%, 30%, 25%, 20%, 15%, or 10%. The ink composition may comprise from about 20% to about 95% water. In some cases, the ink composition may contain greater than or equal to the following amounts of water, about: 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%.
The reflective layer may have poor adhesion to the article and/or to any adjacent ink-layer(s) in the transfer material. For example, aqueous inks (e.g. versus solvent inks and curable inks) are generally known to have poor adhesive properties. Alternately, the reflective layer may be formed by the insertion of a foil, label, or other pre-formed reflective material that may be attached to the article or included in the transfer material, for example via a decoration station (vide infra). Where the reflective layer has poor adhesion to any adjacent layer in the transfer material, or to the article itself, the reflective layer may have an adhesive layer immediately adjacent.
The material 22, such as the ink(s) may be applied to the transfer component 24 in a predetermined pattern. The term “predetermined pattern”, as used herein, refers to any type of printed pattern including but not limited to words, figures (e.g., pictures), images, indicia or designs that is determined prior to the initiation of printing.
The adhesive deposition device 28 may be optional, at some stages of the process, in some embodiments. If the material (such as ink or varnish) previously deposited on the transfer component 24 has sufficient adhesive properties to adhere to the surface 12 of the articles 10, a separate adhesive deposition device for this purpose may not be necessary. In embodiments which specify that an adhesive is being used, there will be an adhesive deposition device 28.
The Adhesive
The adhesive deposition device 28 can be any suitable type of device for depositing an adhesive onto at least a portion of the previously deposited material(s) and/or the transfer component 24. Suitable adhesive deposition devices 28 include, but are not limited to: print heads, nozzles, and other types of material deposition devices (e.g. slot-coating, gravure systems, screen-printing systems, flexographic systems, etc.). If a print head is used to deposit the adhesive, it can comprise any of the types of print heads that are described above as being suitable for use as a deposition device.
The adhesive can be any material that is suitable for adhering the transfer material 22 to the articles 10 when the transfer component 24 is brought into contact with the surface 12 of the articles 10. This will enable the transfer material 22 to be transferred from the transfer component 24 to the surface 12 of the articles 10. Suitable adhesives include, but are not limited to: pressure sensitive adhesives, curable adhesives such as visible light, UV, or Electron Beam curable adhesives, water-based adhesives, solvent-based adhesives, solid adhesives (e.g., 100% solid, monomer-based adhesives), heat setting (or thermally activated) adhesives, hybrids of any of the foregoing, and two-part or multi-part adhesives (for example two-part epoxy adhesives). Any energy-curable adhesive may be a step-growth curing adhesive, dual step growth curing adhesive, or chain growth curing adhesive. In some cases, it may be desirable for the adhesive to be of a non-heat activated (or thermally-activated) type, such as in the case of heat transfer labels.
It may be desirable for the adhesive to contain colorants. The terms “color” and “colorant”, as used herein to describe ingredients that are added to the compositions, include dyes (which may be in the form of liquids) as well as pigments (which may be in the form of particles).
In the case of two-part epoxy adhesives, the first part can be applied by one deposition device and the second part can be applied by a second deposition device. For example, both parts of the adhesive composition can be applied on the transfer component 24, and the chemistry can be formulated so that the adhesive composition will cure sufficiently to provide the transfer within the allotted process time (for example, within the 1-10 second range). In some cases, the first part can be applied to the transfer component 24 and the second part can be applied to the surface 12 of the article 10. With any of the adhesive systems, it may be desirable to at least partially cure the adhesives prior to contacting the article in order to control squeeze out/flow of the adhesive.
In some cases, an adhesive and/or its parts are capable of being applied by inkjet printing for precise application. Such adhesives may be considered to be pigmented (ink-jet) adhesives or such pigmented compositions may be considered to comprise inkjet inks. The inkjet-able adhesives may be described in terms of their Ohnesorge number. The Ohnesorge number (Oh) is a dimensionless number that relates the viscous forces to inertial and surface tension forces. In cases in which the inkjet printer has a plurality of nozzles having openings with a diameter from about 10 μm to about 200 μm, alternatively from about 10 μm to about 50 μm, the energy curable adhesive may have an Ohnesorge number that is between about 0.1 and about 1 where the characteristic length used to calculate the Ohnesorge number corresponds to the nozzle diameter.
In some embodiments, the transfer material 22 has an adhesive that require curing/activation by radiation/energy (such as electron beam or UV radiation). In many cases, the transfer material—including both the decoration/ink layer and the adhesive—is positioned between the transfer component and the surface of the article during application of the transfer material to the surface of the article. If the article is transparent or substantially transparent to the curing/activating radiation (e.g. electron beam or UV radiation) it may be possible to cure the adhesive by transmitting the curing/activating radiation through at least a portion of the body of the article. If the article is not transparent or substantially transparent to the curing/activating radiation (e.g. electron beam or UV radiation), the radiation must be transmitted through both the transfer component and the transfer material in order to reach the adhesive.
This may require that the curing radiation must also be transmitted through a decoration or ink layer. There are difficulties involved in passing UV light through a decoration or ink layer. These include the tendency for the decoration or ink layer to absorb and/or reflect UV light, which will result in some/much of the UV light not reaching the adhesive layer. This can result in the need for increased dosages of UV radiation in an effort to ensure that an adequate amount reaches the adhesive to cure the adhesive. It is, therefore, desirable to provide a process that provides improved efficiency in the cure-through process. Additionally, it may be desirable to design the radiation source and the adhesive so that processes provided may utilize certain ink materials and/or certain energy wavelengths that improve the amount of radiation that is transmitted through decoration or ink layers. It is also desirable to provide energy curable adhesives that are more readily cured in such a cure-through process.
When UV radiation is used as the curing radiation, improvements in the cure through efficiency are achieved in several manners. One manner is by utilizing UV radiation comprising at least some waves having wavelength of greater than or equal to about 400 nm, alternatively from greater than or equal to about 400 nm and less than or equal to about 700 nm, in order to improve the amount of UV radiation that is able to pass through the decoration or ink layers. Another manner is by developing and utilizing a UV curable adhesive comprising photo-initiators that activate with relatively low radiation dosing and/or which are activate-able by a UV wavelength of greater than or equal to about 400 nm, alternatively from greater than or equal to about 400 nm and less than or equal to about 700 nm. Such adhesive compositions can, then be developed that cure as fast as possible, and/or with as little UV dosage as possible, and/or at select radiation wavelengths.
Non-limiting examples of adhesives include, acrylates, thiol-acrylate, thiol-ene-acrylates, urethane acrylates, polyester acrylates, amino acrylates and epoxy acrylate
As an alternative to UV radiation, electron beam radiation may be used in such a cure-through process. Electron beam radiation is generally more able to penetrate the colorants in the ink-layers and therefore more available to cure any inks or adhesives that may under-lie the outermost ink layers. In the case where electron beam radiation is used to cure the adhesive, the ebeam-curable inks and/or adhesives may not require a photoinitiator, or need only a low level of a single photoinitiator.
Photoinitiators
Any radiation curable ink and/or adhesive compositions, in particular UV or visible radiation-curable inks and/or adhesives, may further comprise at least one photoinitiator. In some cases, the ink and/or adhesive compositions may comprise two or more photoinitiators. For example, the compositions may comprise two or more specific photoinitiators that are sensitive to different wavelengths. For instance, a first photoinitiator at a first concentration (such as at a low level) can be used to pin the ink (and/or adhesive composition) at a specific wavelength without impacting the ability of the adhesive to form a bond, then a second photoinitiator at a second concentration (formulated at a higher concentration) can be sensitive to a second wavelength and be intended to completely cure through the entire ink and adhesive system. The term “pin” means to partially cure the composition. This can be used so that the ink (and/or adhesive) is gelled or at least partially solidified to ensure that there is no smudging of the ink (and/or adhesive (or oozing of the adhesive)) by contact prior to full curing and transfer. The combination of two or more photoinitiators may have absorption ranges that do not overlap, or they may partially overlap. Examples of photoinitiator absorption ranges that do not overlap include, but are not limited to: about 250 to about 350 nm; about 400 nm to about 500 nm; about 550 nm and greater (alternatively about 550 nm to about 670 nm).
The energy curable compositions may comprise a total photoinitiator concentration of from about 0.1% or about 0.2% to about 15%, alternatively about 3% to about 15%, based on the weight of the composition. For photoinitiators that are added for the purpose of pinning (as opposed to curing through), the concentration may range from about 0.2% to about 3%, based on the weight of the composition. For ebeam-curable inks and/or adhesives, the compositions may not require a photoinitiator, or need only a low level (such as between greater than zero and less than or equal to one of the following amounts, about: 5%, 1%, or 0.5%) of a single photoinitiator.
The photoinitiators may be Norrish Type I or Norrish Type II free radical photoinitiators. The photoinitiators may comprise any of the following, or be selected from the group of alpha hydroxyl ketones, alpha amino ketones, acyl phosphine oxides, benzyldimethyl ketals, benzophenones, thioxanthones, and combinations thereof.
For example, alpha hydroxyl ketones may comprise: 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone, 1-hydroxycyclohexyl-phenyl-ketone, 2-hydroxy-2-methylpropiophenone; oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone]; 1-[4-(2-Hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propanone; 1-[4-[(4-benzoylphenyl)thio]phenyl]-2-methyl-2-[(4-methylphenyl)sulfonyl]-1-propanone; and mixtures thereof;
Alpha amino ketones may comprise: -methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-4′-morpholinobutyrophenone, bis(p-(N,N-dimethylamino)phenyl)ketone; and mixtures thereof, and/or
Acyl phosphine oxides may comprise: 2bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide [BAPO], 2,4,6-trimethylbenzoyldiphenyl phosphine oxide [TPO or MAPO], 2,4,6-trimethylbenzoyl phosphine oxide; ethyl-(2,4,6-trimethylbenzoyl)phenylphosphinate; a 20/80 blend of phenyl bis(2,4,6-trimethyl benzoyl)phosphine oxide and a phosphine oxide derivatives; and mixtures thereof.
In further nonlimiting examples, the photoinitiators may comprise any of the following: 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, 2-hydroxy-2-methylpropiophenone, 2-hydroxy-4′-(2-hydroxyethoxy)-2-methylpropiophenone, 1-hydroxycyclohexyl-phenyl-ketone, 2,2-dimethoxy-1,2-diphenylethan-1-one, 2,4,6-trimethylbenzoyldiphenyl phosphine oxide, 2-benzyl-2-dimethylamino-4′-morpholinobutyrophenone, bis(.eta.5-2,4-cylcopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrol-1-yl)-phenyl), 2,4-bis (trichloromethyl)-6-p-methoxystyryl-S-triazine, 4,4′-bis(diethylamino)benzophenone, a mixture of 2-isopropylthioxanthone and 4-isopropylthioxanthone; 2-Chlorothioxanthone; 1,3-di({α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetylpoly[oxy(1-methyl ethylene)]}oxy)-2,2-bis({α-[1-chloro-9-oxo-9H-thioxanthen-4-yl)oxy]acetyl poly[oxy(1-methylethylene)]}oxymethyl) propane; and, 1-chloro-4-propoxythioxanthone, 5,7-diiodo-3-butoxy-6-fluorone; 2,4,5,7-Tetraiodo-3-hydroxy-6-fluorone; and 2,4,5,7-Tetraiodo-3-hydroxy-9-cyano-6-fluorone and mixtures thereof. In some embodiments, a photoinitiator may comprises a low migratory photoinitiator.
In alternative embodiments, the compositions may be void of photoinitiators.
Optional Ingredients
The ink and/or adhesive compositions may further include any of a number of optional ingredients such as adhesion promoters, wetting agents, and inhibitors.
Energy Sources
The apparatus 20 may further comprise one or more optional energy sources. The optional energy source(s) such as energy sources 50A and 50B, can be used for curing any curable adhesive, ink, or varnish. The optional energy source(s), such as 50A may be located adjacent to (that is, on the same side as) the transfer surface 24A of the transfer component. The energy source 50A adjacent the transfer surface 24 can be used to cure the material (such as ink or varnish) deposited on the transfer component 24 by deposition device 26. Such curing can take place prior to any adhesive being applied by the adhesive deposition device 28. There may also be another optional energy source, such as energy source 50B, that is located adjacent to the back surface 24B of the transfer component 24 to cure any adhesives applied by the adhesive deposition device 28. The type of optional energy source will depend on the type of substance being used. The optional energy source can comprise any suitable type of device including, but not limited to: a heat source (such as a heat tunnel, or an infrared lamp); a UV lamp; an electron beam; or other energy source.
The electron beam source may operate with an accelerating voltage from about 80 kV to about 300 kV. For example, the electron beam source may operate with an accelerating voltage from about 100 kV to about 250 kV, alternatively from about 150 kV to about 250 kV.
The target dosage at the surface of the article being treated must be sufficient to ensure adequate curing of one or more (e.g., multiple) layers of ink, varnish, adhesive and such. For example, the target dosage at the surface of the article may be greater than or equal to any of the following: 10 kGy, 20 kGy, 30 kGy, 40 kGy, 50 kGy, or 60 kGy. Alternately, target dosage should not be so great that the electron beam energy begins to damage the article itself. For example, the target dosage at the surface of the article may be less than 100kGy or less than 90kGy or less than 80kGy.
If a UV-curable adhesive is used, at least sections of the transfer component 24 having the transfer material thereon, as well as the overlying layers of the transfer material may need to be transparent to UV light to allow the adhesive to be cured through the overlying layers and the transfer component 24. The curing may be initiated prior to, during, or after the transfer of the transfer material from the transfer component 24 to the surface of the article. Of course, if the adhesive is of a type (such as a pressure sensitive adhesive) that does not require curing, the energy source will not be necessary for the adhesive. It may still be necessary to provide a curing energy source of the inks, if the inks are energy-curable (i.e. UV-curable).
In some cases, it may be desirable for the adhesive to have a sufficiently low tack (a first level of tackiness) during the initial stage of contacting the article 10 with the transfer component 24 (or contacting the transfer component with the article) so that at least portions of the transfer material 22 may be repositioned, such as by sliding (e.g., slip) along the surface 12 of the article 10 in order to conform to the same without damage to the transfer material 22 or the transfer component 24. If the adhesive is a type that can be cured, at this initial stage, the adhesive may be uncured, or only partially cured. Once the transfer component 24 with the transfer material 22 thereon is conformed to the surface of the article 10, pressure may be applied to the transfer component in a direction substantially normal to the surface of the article in order to conform and/or adhere the transfer material 22 to the surface of the article 10. It may be desirable for the ink component to be fully cured before normal pressure is exerted on the transfer component so that the ink will not undesirably spread, distorting any image, etc. and/or causing the ink to ooze out of the transfer material.
The Decoration Station(s)
The apparatus 20 can also comprise a decoration station. The decoration station is a station at which a visual, tactile, or olfactory effect is applied by means of material deposition that is applied directly or transferred to an article 10 or by transforming a property of an article, or combinations thereof. An example of transforming a property of an article without transferring a material to the surface of the article is imparting an image on the surface of an article by a laser. A single decoration station can be used to apply a single decorative effect or multiple decorative effects. Alternatively, multiple decoration stations can be used to apply the decorative effect(s). The decoration may occur before or after the printing of a material on the transfer component 24, or even directly onto the articles before or after the transfer material 22 is applied to the articles 10.
In some embodiments, the decoration station may comprise a station for depositing a reflective material such as a metallic substance on the transfer component 24 and/or onto one of the substances thereon. (In the latter case, the metallic substance would be deposited indirectly on the transfer component 24.) A metallic substance may be used to provide the article 10 with a metallic effect. For example, as shown in
In some embodiments, the decoration station may comprise a station for adding a tactile effect to the transfer material 22 and, thus, to the article 10. The tactile effect may comprise a built up texture that is transferred to the surface 12 of the article 10. The texture can be created by depositing a textured substance on the transfer component 24 before, during or after depositing other substances on the transfer component 24. Alternatively, the texture can be created by using a textured transfer component 24. It may be desirable that the substance that creates a tactile effect on the surface 12 of the article 10 does so by creating a texture with height greater than about 3 microns.
The Transfer Material
It should be understood that all of the components shown in
The process herein may be described in terms of depositing one or more of the materials described above on the transfer component 24. It should be understood, however, that it is not necessary that a particular material be deposited directly on the surface 24A of the transfer component 24. The depositing of the material on the transfer component 24 may include depositing the material directly on the surface 24A of the transfer component 24, or indirectly depositing a material on the surface 24A of the transfer component 24, such as by depositing one material (for example an adhesive) on top of another material (ink or reflective material) that is already on the surface 24A of the transfer component 24.
In addition, although the components of the composite transfer material 22 are shown as layers in
The release agent 58 may be used to ensure that the transfer material 22 releases cleanly from the transfer component 24 and transfer to the surface 12 of the articles 10. The release agent 58 may be continuous in the machine direction as shown in
The Conveyor
The conveyor 30 may be any suitable type of conveyor. In
The apparatus 20 shown in
The conveyor 30 can be any suitable type of device for conveying the article(s) 10 so that the articles 10 may contact, or be contacted by, the transfer component 24 and have the transfer material 22 transferred to the surface 12 of the articles 10. The term “conveyor”, as used herein, refers to devices that move articles generally, and is not limited to conveyor belts. Suitable conveyors include, but are not limited to: turret conveyors, star wheel conveyors, endless loop conveyors which may be in the form of tracks, belts, chains, and the like, puck conveyors, and magnetic servo car conveyors.
In the embodiment shown in
The Conforming Component
The conforming component 40 can be any suitable type of component for conforming the transfer material 22 to the surface 12 of the article 10. It should be understood, however, that the conforming component 40 is not necessary in the second and third categories of processes described herein. It should also be understood that although the aforementioned categories of processes may be shown as continuous processes, they can also be carried out as intermittent processes at fixed stations. The conforming component 40 can be in forms that include, but are not limited to: stationary cavities, and conveyors with cavities thereon.
The conforming component 40 shown in
The conforming component 40 may comprise at least one of the components of a station for modifying the transfer component 24 with the transfer material 22 thereon so that the transfer material 22 conforms to the surface 12 of the article 10. The transfer component 24 with the transfer material 22 thereon will have initial dimensions and an initial configuration prior to the modifying step. The terms “modify” or “modifying”, as used herein with respect to the transformation that the portion of the transfer component 24 with the transfer material 22 thereon undergoes may include at least one of: (1) changing the dimensions of the portion of the transfer component 24 with the transfer material 22 thereon by increasing their dimensions in at least one direction by stretching the same; (2) changing the dimensions of the portion of the transfer component 24 with the transfer material 22 thereon by reducing their dimensions in at least one direction such as by shrinking or contracting the same; or (3) at least temporarily deforming, deflecting, flexing, or bending a portion of the transfer component 24 with the transfer material 22 thereon to conform to the configuration of the surface 12 of the article 10.
It should be understood that when the conforming component 24 with the transfer material 22 thereon is described herein as undergoing a modification, the transfer material 22 will be similarly modified. Thus, if the transfer component 24 with the transfer material 22 thereon is stretched (for example), the transfer material (which may be in the form of an image or the like) will also be stretched. If the portion of the transfer component 24 with the transfer material 22 thereon is thereafter relaxed and contracts, the image will also contract.
In some embodiments, the term “modify” may be further specified herein as either including or excluding substantial compression of the thickness of the transfer component 24 (that is, compression greater than about 5% of the uncompressed thickness of the transfer component 24) as the primary type of modification, or as an aspect of the modification. It should be understood, however, that although the modification may, for example, be one of stretching to modify the transfer component 24 with the transfer material 22 thereon, the transfer itself may rely on some level of compressive force being applied in the direction of the thickness of the transfer component 24 to ensure good contact for the transfer of the transfer material 22 to the surface 12 of the article. In some embodiments, the term “modify” may be further specified as excluding bending or wrapping the transfer component 24 about a cylindrical object. In such cases, the transfer component 24 may be said to be modified other than in the configuration of a portion of a cylindrical surface. That is, if bent, the transfer component 24 with the transfer material 22 thereon is bent such that it may have portions with different radii and/or axes of curvature.
In the various different types of processes described herein, there can be several aspects to transferring the transfer material 22 from the transfer component 24 to the surface of the article 10. As described above, a portion of the transfer component 24 with the transfer material 22 thereon, may be modified. These aspects comprise: contacting, conforming, and transferring. More specifically, the transfer operation will involve an aspect of contacting the article 10 with the transfer material 22. The transfer operation may also involve an aspect of conforming the transfer material 22 to the configuration of the target surface 12 of the article 10. The transfer operation will also involve a transfer of the transfer material 22 from the transfer component 24 to the target surface of the article 10. The order in which some of these aspects occur relative to each other may vary depending on the type of process used herein.
The aspect of modifying the transfer component 24 with the transfer material 22 thereon can occur at any of the following times: prior to contact between the article 10 and the transfer material 22; simultaneously with contacting; after contacting; or any combination thereof. The contact may occur in any of the following manners, by: moving the article 10 to make contact with the transfer component 24; moving the transfer component 24 to make contact with the article 10; or moving both the article 10 and the transfer component 24 to contact each other.
The aspect of conforming the transfer material 22 to the configuration of the surface 12 of the article 10 is typically associated with the aspect of modifying the transfer component 24 with the transfer material 22 thereon. In some cases, the aspect of conforming the transfer material 22 to the configuration of the surface 12 of the article 10 can occur before the transfer material 22 is brought into contact with the surface 12 of the article 10, simultaneously with contacting, or after contacting, or any combination thereof.
The aspect of contacting the article 10 with the transfer material 22 typically occurs before there can be a transfer of the transfer material 22 to the surface 12 of the article 10. The aspect of transferring the transfer material 22 from the transfer component 24 to the surface 12 of the article 10 may occur simultaneously, or after contacting the article 10 with the transfer material 22.
It may be desirable to ensure that the transfer material 22 conforms closely to the surface 12 of the articles 10. This will reduce the chance that there will be wrinkles in the transfer material 22 and that air is trapped or entrained between the surface 12 of the article and the transfer material 22. This will also reduce the chance that portions of the transfer material 22 will span between portions of the surface 12 which may have a depression therein, rather than adhering closely to the surface of the article in those depressions. Also, if there is too large of a gap between the transfer material 22 and the article, then the adhesive will not contact the surface 12 of the article 10 and possibly not transfer that portion of the transfer material 22 to the article 10.
In addition to the foregoing, in some cases, it may be desirable to optionally pre-stretch an extensible transfer component 24 prior to and during the deposit of a material thereon. The transfer component 24 with the transfer material 22 thereon can then be temporarily relaxed before conforming the same to the surface of an article 10. Following the relaxation, the transfer component 24 with the transfer material 22 thereon can then be modified, such as by stretching, to conform the same to the surface of an article 10. Applying the transfer material 22 to a pre-stretched transfer component 24 may reduce or eliminate any negative effects on the transfer material during the subsequent step of modifying (such as by stretching) the same when conforming the transfer component 24 with the transfer material 22 thereon to the surface 12 of an article 10. The negative effects may include, but are not limited to damage to any image on the transfer material, and/or reduction in the quality of the image. For example, if the deposition device 26 comprises an ink jet printer, and the transfer component 24 is unstretched during printing, the number of drops of ink per inch (DPI) applied during printing will have a first value, DPI1. After stretching the transfer component with the transfer material 22 thereon to conform the same to the surface 12 of an article 10, the DPI as applied to the surface 12 of the article 10 will have a second value DPI2 that is reduced due to the stretching. If the transfer component 24 is stretched prior to and held in a stretched condition during the printing process, however, when the transfer component 24 with the transfer material thereon 22 is subsequently stretched to conform the same to the surface 12 of an article 10, the DPI2 in this case as applied to the surface 12 of the article will be greater than it would have been if the transfer component was not pre-stretched. In the latter case, DPI2 may approach DPI1, or equal DPI1, or even be greater than DPI1 (the latter case occurring if the pre-stretching is greater than stretching during conformation).
In the first category of processes shown in
As shown in
It may then be desired to take additional optional steps to further conform the transfer component 24 with the transfer material 22 thereon to the surface 12 of the article 10. This may be done by pulling the transfer component 24 toward the article 10, or exerting a pushing force on the back surface 24B of the transfer component 24, or by a combination of such forces. The following figures show several non-limiting ways of further conforming the transfer component 24 with the transfer material 22 thereon to the surface 12 of the article 10.
Referring back to
As shown in
In the embodiment shown in
The constraining components 90 can be any suitable type of components that are capable of maintaining a portion of the transfer component 24 in tension so that the article 10 can be moved into the constrained portion of the transfer component 24 to conform the transfer component 24 to a portion of the surface 12 of the article 10. The portion of the transfer component may be pulled taut. In other cases, the portion of the transfer component need only be held in a manner that provides resistance when the article is pushed into the constrained portion of the transfer component 24. The constraining components 90 may also ensure that any stretching of the constrained portion of the transfer component 24 during the conformation step is isolated so that adjacent portions of the transfer component 24 are not stretched. In a continuous process, the constraining components 90 may also be capable of allowing the transfer component 24 to move in the machine direction.
Suitable constraining components 90 include, but are not limited to: constraining blocks, clamps, and frames (the latter which may have a configuration similar to a picture frame). In the embodiment shown in
In other embodiments, such as shown in
The constraining components 90 may be joined to a constraining component conveyor 92 that moves the first and second constraining components 90A and 90B in the machine direction. The constraining component conveyor 92 can travel in the machine direction with the transfer component 24. The transfer component 24 is fed between the opposing first and second blocks 90A and 90B. The first and second blocks 90A and 90B may be movable toward and away from each other to clamp the transfer component 24 therebetween. The first and second constraining components 90A and 90B may also be movable relative to adjacent pairs of first and second constraining components 90A and 90B so that they may be adjusted to place the proper amount of tension on the portion of the transfer component 24 that spans between adjacent constraining components 90. The constraining components 90 isolate a portion of the transfer component 24 so that when an article 10 is pushed into the isolated portion of the transfer component 24, only the isolated portion of the transfer component 24 is stretched, and the adjacent portions of the transfer component 24 are not stretched.
Prior to and after clamping, there may be relative motion between the transfer component 24 and the constraining components 90. The transfer component 24 may be moved past the constraining components 90 at a constant velocity, or the velocity of the transfer component 24 may be varied, if desired. The movement of the transfer component 24 may be continuous, or if desired, intermittent. The constraining components 90 will be moving at the same velocity as the transfer component 24 after the constraining components are clamped onto the transfer component 24. After clamping, the transfer component 24 and constraining component conveyor 92 may move at a constant velocity, or the velocity of the transfer component 24 may be varied, if desired. The movement of the transfer component 24 and constraining component conveyor 92 may be continuous, or if desired, intermittent. The article 10 will be generally moving in the machine direction as well, but may also have a relative velocity towards the transfer component 24 until fully contacting the transfer component 24. After fully contacting, the article 10 and the transfer component 24 may have no relative motion but may travel together in the machine direction until the transfer is complete.
As in the case of the first category of processes, it may also be desirable to further conform the transfer component 24 with the transfer material 22 thereon to the surface 12 of the article 10 in the second category of processes.
In the embodiment shown in
As shown in
The shaped die 172 can be any suitable component that is capable of forming a nip 170 with the surface 12 of an article 10 and is configured to force the transfer component 24 with the transfer material 22 thereon into close contact with the target surface of the article 10. The shaped die 172 can be of any suitable configuration. The shaped die 172 can have a surface 174 comprising portions that are planar, concave, convex, or combinations thereof. The overall configuration of the shaped die 172 will depend on the motion that the die 172 undergoes during the process.
There can be any suitable type of relative motion between the article 10 and the shaped die 172. The articles 10 may either be translated or rotated through the nip 170. The shaped die 172 may also either be translated or rotated through the nip 170. The articles 10 and the shaped die 172 may be movable by the same type of motion (e.g., both may rotate; or both may translate). In other embodiments, the type of movement of the articles 10 and the shaped die 172 may differ. For example, the articles 10 may move by translation, and the shape die 172 may move by rotation. Alternatively, the articles 10 may rotate and the shaped die 172 may move by translation.
As shown by the solid arrows in
The apparatus 20 may further comprise one or more additional stations or devices that are positioned at any desired location along the article conveyor. Such additional devices may include, but are not limited to pre-treatment devices for pre-treating the surface of the articles, such as flame treatment, corona treatment, and plasma jet treatment devices.
Numerous variations of the embodiments described herein are possible. For example,
The portions of the surface 12 and 12′ may be opposing portions of the surface (e.g., on opposite sides of the article) and/or portions of the surface that may be spaced apart. The opposite sides can, for example, be the front and the back of the article; or, two different sides of the article. In such cases, or in other cases, however, some or all portions of the surface 12 and 12′ to which the apparatus is capable of transferring material need not be opposing portions, and some or all portions of the surface 12 and 12′ may be contiguous and, thus not spaced apart. In one non-limiting example of the former, one transfer material could be applied to at least a portion of the front of the article and may also wrap around a portion of the bottom of the article. Another transfer material could be applied to at least a portion of the back of the article and also wrap around a portion of the bottom of the article. Since both transfer materials wrap around a portion of the bottom of the article, the portions that wrap around the bottom of the article would not be considered to be on opposing surfaces of the article since they would both be disposed on the bottom of the article.
In the embodiment shown in
In the embodiments shown in
The apparatuses shown in
In this embodiment, the transfer component 24 may be transported past a printing station comprising a substance deposition device 26. The transfer component 24 may then be transported past an optional curing device, and an adhesive application device (similar to those shown in the other drawing figures herein). Following the application of the desired substances to the transfer component 24, the transfer component 24 is separated longitudinally into separate webs. The transfer component 24 can be separated into separate webs in any suitable manner. In some cases, the transfer component 24 may comprise multiple side-by-side webs that are merely diverted such as by turning bars 178 to separate the same. In other cases, the transfer component 24 may be slit to separate the webs. In this case, the first web, upper web 241, applies the transfer material 22 to a first portion, such as an upper portion, on the surface of an article 10. The second web, lower web 242, applies the transfer material 22 to a second portion, such as a lower portion, on the surface of an article 10.
The embodiment shown in
In addition, depending on the arrangement of the turning bars 178, the embodiment shown in
The particular embodiment shown in
While the vacuum is retained in the portion 186A of the chamber enclosing the first surface 24A of the transfer component 24 (the surface adjacent to the article 10), the air pressure is increased in the portion 186B of the chamber on the opposite surface 24B of the transfer component 24. This provides additional force to push the transfer component 24 against the surface 12 of the article 10. The air pressure can be increased in the portion 186B of the chamber on the opposite surface 24B of the transfer component 24 in any suitable manner, including by venting this portion of the chamber to the atmosphere, and by adding air to this portion of the chamber through port 192. In some cases, it may be desired to have a slight positive pressure differential in the portion 186B of the chamber on the opposite surface 24B of the transfer component 24 so that the transfer component 24 bends toward the article 10 before the article 10 is pressed into the transfer component 24.
Any curing of the transfer material 22 (or portions thereof such as curable adhesives or varnishes) on the surface 12 of the article 10 can then take place, such as by electron beam, UV light, etc. In order to cure by UV light, the component 184 on the side of the transfer component 24 opposite the article 10 can have a window 194 therein that is made of a transparent material such as glass, PLEXIGLAS®, or other transparent material. The transfer component 24 should also be transparent to UV light. In cases in which the transfer material 22 comprises a heat curable component, this component can be cured by heat using a heating element located inside the chamber 186. Of course, it the adhesive is not of a type that requires curing by an energy source, such as a pressure sensitive adhesive or a 2-part adhesive chemistry, then it is not necessary to use any energy source. The transfer component 24 transfers the transfer material 22 to the surface 12 of the article 10 and is then removed from contact with the surface 12 of the article 10. This optional process variation may reduce the amount of air that is trapped between the transfer component 24 with the transfer material 22 thereon and the surface 12 of the article 10 so that there are no visible air bubbles after the transfer material 22 is adhered to the article 10.
In the case of the first category of processes, similar adjustments to the pressure on either side of the transfer component 24 can be made by using an element 40 with a cavity 24 therein such as that shown and described in
The Article
The methods and apparatuses described herein are particularly useful for transfer printing on articles with curved surfaces. For instance, instead of attaching a pre-printed label to an article such as a bottle, the apparatus and method can be used to transfer the subject matter of the label on the article. Of course, the apparatus and method are not limited to printing subject matter which serves as a label on the articles. The apparatus and method are also useful in indirectly printing designs and the like on articles.
The transfer processes and apparatuses described herein may provide a number of advantages. It should be understood, however, that such advantages are not required to be present unless set forth in the appended claims. The processes and apparatuses may be capable of decorating portions of articles that are currently difficult to print by direct printing, or transfer processes. Specifically, the processes described herein can be capable of transferring a transfer material from the transfer component to articles with complex three-dimensional shapes and/or which have surface features that differ in height (or depth) by more than a limited extent. Further, the processes described herein can be capable of transferring a transfer material comprising a reflective layer with relatively high specular reflectance, specifically, the processes described herein can be capable of providing a reflective layer with a smooth surface and of transferring that transfer material to a complex article that may otherwise have a rough surface.
The transfer processes described herein provide several advantages over conventional compressible pads that are used for transferring materials, including the advantage that the thickness of the transfer component 24 does not vary extensively when transferring the transfer material to an article, and thus reduces and variations in the printed image that may occur over time due to wear on a compressible pad. The transfer process described herein may also provide advantages over methods that use a conventional transfer pad to transfer the material in which air can be trapped between a depression in the surface of the article and the transfer pad. These and at least some of the other distinctions and advantages over various known methods and articles produced by such methods are described below.
The transfer methods and articles described herein provide advantages over heat transfer label processes and screen printing processes and the articles formed thereby in that heat transfer label processes and screen printing processes are not believed to be capable of forming a continuous image on multiple portions of the surface of a three-dimensional article as described herein. The transfer methods and articles described herein provide advantages over vacuum sublimation processes and hydrographic processes and the articles formed thereby. The inks applied to articles by vacuum sublimation processes penetrate into the surface of the articles, and the inks applied to articles by hydrographic (water transfer printing) processes are etched into the surface of the articles. This makes these articles less suitable or unsuitable for recycling (which requires removal of the inks) than the articles formed by the transfer methods described herein on which the inks are applied on top of the surface (and may follow any contours on the surface, such as small waviness which may be present on plastic surfaces), but do not penetrate into the surface, and thus can be substantially completely removed for recycling and/or during a recycling process.
The transfer methods and articles described herein provide additional advantages over hydrographic processes and the articles formed thereby. Such processes are relatively slow and involve: preparing the surface of the substrate; priming the surface; painting the surface; and, processing the substrate by preparing a printed water-soluble polyvinyl alcohol film which is believed to utilize solvent-based ink, placing the film in a water dipping tank, applying an activator solution to the film to soften the base coat on the substrate, dipping the substrate into the water on top of the film to transfer the printing from the film to the substrate, rinsing and drying the substrate, and applying a clear coating. The transfer methods described herein take place in a non-aqueous environment in which no part of the article is at least partially submerged in water which require that the article be rinsed and dried. The articles described herein may be free of a softenable base coat and an activator (e.g., residual activator).
The transfer methods and articles described herein are also distinguishable from pre-printed thermoforms. Pre-printed thermoforms are articles that are typically made of plastic. After the article is printed, the article with the printing thereon is thermoformed (placed in an oven and formed) into the desired configuration. As a result, the article and the printing thereon are typically stretched the same amount during the thermoforming process. In the case of the transfer methods and articles described herein, the article, such as a blow molded plastic container, may have been stretched during formation (during the blow molding process). The transfer material may be stretched during application to the surface of the article. As a result, the plastic container will typically be stretched a different amount than the transfer material.
After the transfer material 22 is transferred to the article(s) 10, the article(s) may be transferred by the conveyor to another conveyor or apparatus for further processing. For example, if the article(s) 10 are bottles, the bottles may be transferred from the conveyor to a filler, and capper.
Subsequent to transfer of the transfer material to the surface of the articles, the three-dimensional articles will have a surface with a (reflective) transfer material joined to their surface. In one embodiment the transfer material comprises, from the surface of the article outward: an adhesive; a (first) deposit of ink on the adhesive; and a reflective layer comprising a deposit of ink. In another embodiment the transfer material comprises, from the surface of the article outward: an adhesive; a reflective layer comprising a deposit of ink on the adhesive; and a deposit of ink. In another embodiment the transfer material comprises, from the surface of the article outward: an adhesive; and a reflective layer comprising a deposit of ink. In another embodiment the transfer material comprises, from the surface of the article outward: an adhesive; a (first) deposit of ink on the adhesive; a reflective layer comprising a deposit of ink; and an ink layer comprising a (second) deposit of ink outward from the reflective layer. The articles may further comprise a protective varnish overlying the total of all underlying layers.
The method used to characterize surface texture is 3-D Laser Scanning Microscopy (“3 DLSM”). 3DLSM can be used to collect topographic data over a given area on a sample surface. This 3-D data can be analyzed following ISO standards to quantitatively characterize the microtextural features of that surface; ISO 25178 provides a framework for this characterization.
Film samples for analysis are prepared by obtaining a representative piece of the film sized to fit the analysis instrument. Sample is mounted so as to eliminate or reduce wrinkling without stretching the film. Data is collected using a Keyence VK-X200 series 3D Laser Scanning Microscope (consisting of a VK-X200K controller and a VK-X210 Measuring Unit). The instrument manufacturer's software is used for data collection (“VK Viewer”) and data analysis (“VK Analyzer”); the manufacturer provides an ISO 25178 analysis module that is used to extract parameters in compliance with ISO 25178. Images are collected using 50× objective lens provided with the instrument. Data is acquired using the acquisition software's “Expert Mode” wherein the following parameters are set: height scan range is set to encompass the height range of the sample (this can vary from sample to sample depending on the surface topography of each); step size is set to 0.10 micrometers for the 50× objective; laser intensity and detector gain are optimized for each sample using the autogain feature of the instrument control software (maximizes reflected laser signal without causing detector saturation). Prior to analysis, data is subjected to tilt correction, long wavelength waveform removal (0.1 mm cutoff), and noise removal using medium height cut (following built in algorithm in the analysis software). The entire area of a data set (image) is analyzed using the ISO 25178 module to yield roughness parameters.
Contact angles on substrates are determined using a modified ASTM D7490-13 Standard Test Method for Measurement of the Surface Tension of Solid Coatings, Substrates and Pigments using Contact Angle Measurements.
Contact angles on both sides of the drops of distilled water and diiodomethane (all available from Sigma Aldrich, St. Louis, Mo.) are measured on both sides of the polyethylene film. The two values are then substituted into two separate expressions of the Owens-Wendt-Kaelble equation (one for each liquid). This results in three equations and two unknowns, which are then solved for the dispersion and polar components of surface tension.
Goniometer—An instrument consisting of a controlled light source, a stage to hold the sample, and a microscope or camera for viewing of the drop on the film is required (First Ten Angstrom, Model 200, or equivalent).
Hypodermic Syringe—A gas tight syringe, such as a 1-mL hypodermic, equipped with a No. 27 blunt tipped stainless steel needle, capable of providing 100 to 200 drops from 1 mL.
Water—Type II reagent water (distilled) in accordance with ASTM Specification D1193-99.
Diiodomethane (99+% purity).
The sample should not be touched with the fingers or contaminated in any other way during position on goniometer stage.
Obtain an initial live video image of a calibration standard (FTA calibration standard or similar standard) positioned directly below where the syringe needle would touch the sample holder. Adjust back lighting, front lighting, brightness, aperture, and contrast until a clear image is obtained. There should be a 3 degree look down angle between the camera and the sample surface. Calibrate distance measurements by measuring a standard micrometer. Use the FTA software (version 2.1, build 378 to automatically determine the contact angle. Adjust lighting and camera angle until 85+2 degrees and 55±2 degrees are determined by spherical fit of the stainless-steel ball. Camera angle may be adjusted by adjusting camera height and then trim tilt to bring the sapphire ball vertically into the image. Observe the angle of a line through the centerline of the microscope lens; this is the camera angle. The specimen image magnification should be adjusted to fill ¾ of the screen prior to determining the contact angles.
Thermal regulation (±2 C) is utilized to ensure temperature fluctuations do not significantly influence the measurements. Humidity control (±5% relative humidity) so that the general condition of the surface does not change significantly with change in humidity. In all cases, the humidity and temperature are recorded for each measurement.
Surface contamination is avoided by wearing clean nitrile gloves and working on a clean surface in a room clean of atmospheric contaminates and dust. A 1.5 cm by 2.0 cm rectangle of sample is obtained without contaminating the surface of the substrate except by clean atmospheric gases. A strip of double-sided sticky tape 2 cm wide by 6 cm long is mounted along the edge of the microscope slide longitudinally avoiding wrinkling and trapped air bubbles as much as possible. The sample is mounted on the tape along the edge longitudinally avoiding wrinkling and trapped air bubbles. The sample is mounted on a horizontal stage under the syringe. The edge of the film positioned so that the drop detaches from the needle 5 mm from edge.
Fill syringe with at least 250 μL test fluid (water or diiodomethane), attach 27-gauge blunt tip stainless steel needle, and remove all visible air bubbles from syringe by tapping syringe. Program the pump program in the FTA software with the inner diameter of the syringe. Place syringe in the syringe holder. Firmly attach the syringe plunger to the push plate using clip provided by First Ten Angstroms for the type of syringe being used.
Pump 3 μL of diiodomethane or water at 1.0 uL/s until a dangling drop is formed on the tip of the needle about 200 μm from surface as shown below. Continue to slowly pump the solvent at 1.0 μL/s until a single drop detaches from the syringe and makes contact with the surface. Capture the contact of the drop on the surface with a series of images of the drop wetting out until either the drop does not wet out further (equilibrium contact angle) or 2% of the drop volume has absorbed into the sample if the sample is slightly absorptive.
Make two angle measurements (one on each drop edge) of each of two drops on the film using commercial software designed to extract contact angles from movies or images. If the contact angles on two edges are different by more than 4°, the values should be eliminated, and the test repeated. This measurement is repeated 4 more times on new droplets. The contact angle for the film shall be the average of the five angles measured for each side.
The image acquisition speed should capture at least 10-20 images from the time the drop hits the surface to the time it cannot be resolved from the surface of the sample. This work utilized a capture rate of 205 images/s. The software described above extracted the contact angles from the video feed. Ideally, enough time is allowed for the drop to wet out to equilibrium. However, in highly absorptive systems the drop absorbs into the material before equilibrium is achieved. In these cases in which the drop rapidly (<0.2 s) absorbs into the substrate, video was progressed until 2% of the volume of the drop absorbed into the substrate. The contact angle was recorded at that time point. This might mean the first resolved image in extremely fast absorbing systems if the second image shows more than 2% volume loss.
where:
The Owens-Wendt-Kaelble equation is simplified to the following when a dispersive (nonpolar) solvent such as diiodomethane is used:
The dispersive (nonpolar) component of surface energy (γDsg) is determined. Surface tension properties for diiodomethane are known and included in the table above. The contact angle is experimentally determined using the method delineated above.
Upon inserting the calculated dispersive component of surface energy (γDsg) for the substrate into the Owens-Wendt-Kaelble equation delineated above and using the contact angles determined for water, the polar component of surface energy (γPsg) of the substrate was determined because the surface tension properties for water are known and included in the table above. The dispersive component (γDsg) of the substrate was determined with diiodomethane as explained above.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “90°” is intended to mean “about 90°”.
It should be understood that every maximum numerical limitation given throughout this specification includes every lower numerical limitation, as if such lower numerical limitations were expressly written herein. Every minimum numerical limitation given throughout this specification will include every higher numerical limitation, as if such higher numerical limitations were expressly written herein. Every numerical range given throughout this specification will include every narrower numerical range that falls within such broader numerical range, as if such narrower numerical ranges were all expressly written herein.
All documents cited in the Detailed Description of the Invention are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present invention. To the extent that any meaning or definition of a term in this written document conflicts with any meaning or definition of the term in a document incorporated by reference, the meaning or definition assigned to the term in this written document shall govern.
While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention.
| Number | Date | Country | |
|---|---|---|---|
| 62664967 | May 2018 | US |
