Patent Application
20090072527
The present invention relates to in-mold labels, and more particularly to in-mold labels having holographic images.
In-mold labels (IMLs) and labeling are well known. Such labels are adhered to an article, such as a bottle, during the molding of the article. The label is placed within the cavity of a mold before molding, and the label adheres to the surface of the article during molding.
A typical application of in-mold labeling is in the production of blow-molded containers. A pre-printed label with heat-activated adhesive is placed against the surface of the mold cavity and held in position by vacuum ports and/or static electricity. The mold is closed, and a plastic container blank is heated and inflated within the mold. The hot plastic presses against the label, activating the adhesive and causing the label to adhere to the outer surface of the newly molded container. The mold is opened, and the labeled container is ejected from the mold. Examples are disclosed in U.S. Pat. No. 5,344,305 issued Sep. 6, 1994 entitled “Apparatus for In-Mold Labeling”; and U.S. patent application Ser. No. 11/384,578 filed Mar. 20, 2006 entitled “Laminated Multi-Ply In-Mold Label.”
In-mold labels offer a wide variety of printing, graphic, and other visual treatments. One such treatment is the inclusion of holographic images. Such images require reflective metallized portions created by printing the labels with metallic ink or otherwise depositing metal layers on the label. The quality of the reflective ink or layer depends in part on the relative roughness or smoothness of the material on which the layer is created. Unfortunately, IML materials are relatively rough, and consequently, the quality of the reflective layers and the holographic images have been less than desired.
The aforementioned problems are overcome by the present invention in which a holographic material is formed on a relatively smooth ply that is laminated to a relatively rough base ply. The holographic material can be metallized ink, deposited metal, or any other suitable material. In the disclosed embodiment, the base ply is a known IML material.
The present invention provides a holographic material of extremely high quality on an in-mold label. Consequently, the label provides improved aesthetics over known labels.
These and other objects, advantages, and features of the invention will be more fully understood and appreciated by reference to the description of the current embodiment and the drawings.
One embodiment of the in-mold label (IML) of the present invention is illustrated in
The current embodiment is a laminated two-ply IML. However, the laminated IML may include additional or different plies. For example, a person skilled in the art could extend the described embodiment to an IML having three or more plies. The disclosed is rectangular, but the label could be virtually any shape in view of aesthetic and functional considerations.
a. Base Ply
The base ply 12 generally includes a base layer 18, an adhesive 16 on the lower surface of the base layer 18, and an adhesive 20 on the upper surface of the base layer 18. The current base layer is a plastic film, and specifically is a polyolefin. The surface roughness of this material is medium roughness. Alternatively, the base layer 18 may be constructed of other IML materials or other suitable material known to those skilled in the art. Such materials include without limitation polyolefins, polypropylenes, and polyethylenes.
The adhesive layer 16 is applied to the lower surface of the base layer 18 in any suitable technique or pattern known to those skilled in the art. In the current embodiment, the adhesive layer 16 is responsive to, or activated by, heat. Alternatively, the adhesive layer 16 may be other IML adhesives or other suitable adhesives capable of being activated during the molding process. The current base layer 18 with the adhesive 16 pre-applied is sold by YUPO under the designation ISE 105.
The adhesive layer 20 is applied to the upper surface of the base layer 18 in any suitable technique and pattern known to those skilled in the art. In the current embodiment, the adhesive layer 20 is a laminating adhesive such as solvent gravure (e.g. using alcohol and acetate), moisture cured, 100% solids gravure, and/or UV-cured laminating adhesives. Alternatively, the adhesive layer 20 may be any other suitable laminating adhesive. Although the adhesive layer 20 in the current embodiment is associated with the base ply, in alternative embodiments the adhesive layer 20 may be part of the top ply 14.
The adhesive layer 20 “slaves” the top ply 14 to the base ply 12. Consequently, the top ply 14 will shrink at the same rate (i.e. will follow) the base ply 12 when subjected to the temperatures associated with the molding of the article 5.
b. Decorative Ply
The decorative or top ply 14 generally includes a top film 15 and a metallized layer or other holographic material 22 on the upper surface of the film. The top ply 14 is similar in shape and size to the base ply 12. Alternatively, the top ply 14 may be shaped differently and constructed of other suitable materials. The top ply 14 overlies the base ply 12 uniformly and closely to provide a unified/unitary appearance. In the current embodiment, the top film 15 is clear or transparent. The film 15 alternatively may be translucent or even opaque depending on the desired appearance.
The current film 15 is a plastic film, and specifically is a 0.8 mil polypropylene sold by ITW under the designation BOPP80 Pattern 081. The surface roughness of this material is very smooth. Alternatively, the film 15 may be constructed of other suitable material known to those skilled in the art. Such materials include without limitation polyester, polyvinylchloride, and polypropylene. The important feature of the present invention is that the top ply has a smoother surface (i.e. a lower surface roughness) than the base ply 12.
The current metallized layer or holographic material 22 is created by vacuum metal deposition on the film 15. Alternatively, the holographic material 22 could be a metallized ink or any other material providing relatively high reflectivity and suitable for the formation of a holographic image.
The holographic material 22 is on the upper surface of the film 15 to provide maximum reflectivity and holographic effect. Alternatively, the holographic material 22 could be printed on the undersurface of the top ply.
A holographic image 30 (
Additional layers may be printed or otherwise applied over the holographic material 22. Specifically in the current embodiment, a clear primer 24, such as a water-based primer, is printed directly over the holographic material 22. The primer 24 protects the holographic material 22 and provides a surface on which additional printed layers will better adhere.
Additional printing may be included. For example, the current embodiment includes printed layers 26 and 28 over the primer 24. Alternatively, printing may be included on the lower surface of the decorative ply 14 and/or on the upper or lower surface of the base ply 12. White or other printing may be used to alter the opacity and/or to hide printing on the lower surface of the top ply 14.
In operation, pre-printed and adhesive-coated labels 10 are provided in roll, magazine, or other suitable form (not shown) as known in the art. The labels 10 may be transferred to the interior of a blow mold or an injection mold (not shown) using techniques known in the art. Known molding techniques may be used to form the container and thereby adhere the IML 10 to the molded article 5. Specifically, the IML 10 may be placed into a mold with adhesive 16 facing away from the mold. The adhesive 16 is activated by the molding process, causing the molding 10 to adhere to the article 5. After the molded article has “frozen” or is cured, the molded article 5 with the adhered two-ply label 10 may be removed from the mold. In essence, the IML 10 becomes part of the molded article 5 during the molding process.
In use, the IML 10 provides a holographic image on its top surface and optionally includes additional printing on any of the combined four surfaces of the base ply 12 and the top ply 14. The holographic material is of improved quality primarily because the of surface smoothness of the top ply 14. And therefore the holographic image is of improved quality.
The above description is that of the current embodiment of the invention. Various alterations and changes can be made without departing from the spirit and broader aspects of the invention as defined in the appended claims, which are to be interpreted in accordance with the principles of patent law, including the doctrine of equivalents.
