Abstract:
An expanded content label (ECL) having multiple layers and a heat-activated adhesive. The ECL is intended for use in an in-mold labeling process. A method for applying the ECL includes placing the ECL in a mold, molding an article within the mold thereby activating the adhesive, and removing the article with the label adhered thereto from the mold.

Description:
This is a division of application Ser. No. 09/412,881, filed Oct. 5, 1999, now U.S. Pat. No. 6,422,605. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to labels and labeling, and more particularly to in-mold labels and labeling. 
     In-mold labels 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 prior to molding, and the label adheres to the surface of the article during molding. 
     A typical application is in the production of blow-molded containers. A preprinted label with heat activated adhesive is placed against the inner surface of the mold cavity and held by vacuum ports in the mold. The mold is closed, and the plastic blank is heated and inflated within the mold. The hot plastic presses against the label, activating the adhesive and causing the label to be adhered to the outer surface of the newly molded container. The mold is opened and the labeled container is ejected from the mold. In-mold labels may be furnished as a stack of precut discrete labels or as a continuous web of adjacent labels joined edge to edge and subsequently cut and applied as disclosed in U.S. Pat. No. 5,344,305 to McKillip, incorporated by reference here. 
     Separate from in-mold labels and labeling, expanded contact labels (ECLs) are known. An ECL includes a booklet or leaflet, which includes information such as instructions, product warnings, or ingredients. The ECL is secured either directly to an article or to a base label that is in turn secured to the article. An ECL typically includes a pressure-sensitive adhesive for adhering the ECL to the article. Usually, an overlaminate is included over the booklet/leaflet to prevent inadvertent separation of the booklet/leaflet from the base label. ECLs are applied to molded articles after molding. 
     ECL&#39;s may be made from many materials including paper and thermoplastics. ECL&#39;s fabricated of thermoplastics are not as well suited to in-mold use as paper because of the elevated temperatures. The multiple layers of the plastic ECL are subject to different heat intensities as an article is blow molded. Specifically, the layer nearest the molded article is subjected to higher levels of heat than the layer adjacent the mold. This causes the ECL to buckle, and can even cause the layer to delaminate, rendering the label commercially and aesthetically unacceptable. 
     SUMMARY OF THE INVENTION 
     The aforementioned problems are overcome in the present invention comprising an expanded content label suitable for in-mold use. More specifically, the ECL includes a heat sensitive adhesive to enable application of the ECL in an in-mold process. 
     The present invention enables an ECL to be applied to an article during molding. The invention eliminates the need to apply an ECL to an article after molding. Accordingly, the manufacture of molded containers having expanded content labels is expedited with the resulting benefit of lower cost. 
     A second aspect of the invention is directed to a method of applying the novel expanded content label to articles during the molding of the articles. The method includes the steps of (1) placing an ECL having a heat-activated adhesive within a mold, (2) molding an article in the mold thereby activating the adhesive to adhere the ECL to the molded article, and (3) removing the labeled article from the mold. 
     In a third aspect of the invention, the ECL includes a protective overlaminate. The space between the base layer and the overlaminate—in which the booklet is enclosed—is substantially free of air to prevent air from expanding during the in-mold labeling process and consequently deforming or buckling the ECL. 
     In a fourth embodiment of the invention, the ECL includes a base label and an overlaminate that deform at different rates, so that together within the mold—where they are subjected to different temperatures—they deform at a uniform rate. For example, the base layer may be constructed from a thermoplastic that deforms due to heat at a rate faster than that at which the overlaminate material deforms. In this manner, the rates of deformation of the base layer and the overlaminate material are synchronized according to the levels of heat to which they are subjected. Accordingly, the ECL can be used in an in-mold process without unacceptable deformation of the ECL. 
    
    
     These and other objects, advantages, and features of the invention will be more readily understood and appreciated by reference to the detailed description of the preferred embodiment and drawings. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a sectional view of an expanded content label of the present invention; 
     FIG. 2 is a top plan view of the expanded content label; 
     FIG. 3 is a diagrammatic perspective of the label being placed in a mold; and 
     FIG. 4 is a sectional view of a blow mold and a labeled article therein. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A preferred embodiment of the expanded content label (ECL) of the present invention is illustrated in FIGS. 1 and 2, and generally designated  10 . The label includes a base layer or substrate  12 , a booklet  18  adjacent the base, and a protective overlaminate or cover  16  releasably adhered to either or both of the booklet and the base. Preferably, the base layer  12 , and the overlaminate  16  are constructed of paper. Alternatively, these items may be constructed of plastic or other suitable material. 
     The base  12  includes a linerless heat sensitive adhesive layer  14  on its undersurface. Preferably, the base  12 , and the overlaminate  16  are constructed of the same material. The adhesive layer  14  may be applied to the base  12 , in a variety of manners and patterns, as will be appreciated by those skilled in the art. The adhesive layer  14  is preferably made from adhesives that are responsive or activated by heat. 
     In alternative thermoplastic embodiments, the base layer  12  is constructed so that it is deformed by heat more effectively than the overlaminate  16  is deformed by heat, particularly in a blow mold process. 
     In the preferred embodiment, the booklet  18 , is generally rectangular and formed as a number of pages or panels of paper or plastic stacked in an overlying relationship. The booklet  18  may be also adhered to the base layer  12  with adhesive  19 , which may be opened like the pages of a book, folded open like a foldout map, or any configuration that makes viewing of the information convenient. 
     The overlaminate  16  overlays the booklet  18  uniformly and closely to avoid the entrapment of any substantial amount of air between the overlaminate layer  16  and the booklet  18 . The absence of air pockets prevents substantial distortion or destruction of the expanded content label during the application of heat thereto in an in-mold labeling process. For example, if there were large air pockets adjacent the booklet  18 , during the application of heat, these air pockets would expand, and potentially cause the overlaminate layer  16 , to be disengaged from the base. 
     Use 
     The apparatus and method of applying ECLs to articles in an in-mold labeling process is generally illustrated in FIGS. 3 and 4. Generally included in the apparatus is a label supplying machine (not shown), a transfer device  14 , and a blow mold  50 . The label supplying machine may be any conventional roll or magazine supplier. 
     The transfer device  40  is a pick and place device including a suction cup  44  mounted at the end of a telescoping tube  46 , the opposite end of the tube  46  is mounted to a pivot  48 . As an alternative to a telescoping tube  46 , pivot  48  may be mounted to suitable machinery which moves the pivot suction cup toward and away from the molding device  50 . 
     As depicted in FIG. 4, the blow mold  50  includes first mold half  51  formed with a recess  52 . The recess of the first mold half  50  mates with a recess of a second mold half  53  to form a cavity in which the container or article will be molded. The surface  54  of the mold recess  52  is provided with several vacuum holes  56 . Vacuum holes  56  are disposed over the area of the recess in correspondence with the portion of the molded article to which the label will be adhered. A suitable source of vacuum is connected to the vacuum holes  56 . Pressurized gas is supplied through tube  60 . 
     In operation, preprinted and adhesive-coated ECLs are provided in roll, magazine, or other suitable forms (not shown) as known in the art. As shown in FIG. 3, the ECL  10  is advanced and transferred to the interior of the mold by a transfer device  40 . The transfer device  40  takes a label  10 , from suitable ECL supplying machinery (not shown), and transfers the ECL  10  to a mold  50 . The label supplying machinery (not shown), the transfer device  14 , and blow mold  50  are located in proximity to each other such that the transfer device  14  can transfer expanded content labels directly from the supplying machinery to the blow mold. Notably, any device capable of transferring the ECLs to the mold interiors may be used. 
     With reference to FIG. 3, when an expanded content label is advanced and provided by suitable machinery (not shown), the suction cup  44  is pivoted to a position in front of the label, the tube  46  is telescoped outwardly until the suction cup contacts the rear surface of the expanded content label, and a vacuum is delivered to  46  to suction cup such that the label is held against the suction cup. Tube  46  then withdraws such that the suction cup  44  picks the freshly cut label  36  and pivots toward the blow mold  50 . 
     After pivoting toward the blow mold  50 , tube  46  of the transfer device  14  is extended toward the first mold half  51 . The suction cup  44  and the label  36  carried by the suction cup enter the recess of the mold. The front surface of the label is placed against the recess surface  54  and held in position by vacuum mold  56 . The vacuum of the suction cup  44  is released and the suction cup is withdrawn from the mold half  51 . 
     As shown in FIG. 4, second mold half  53  is closed against the first mold half  51 , and a heated plastic blank is placed in the top opening  58  of the mold. The source of pressurized gas  60  inflates the blank, causing the blank to enlarge and line the mold cavity, thus forming the container C or other article. Heated plastic comes into contact with the expanded content label  10 , and, in particular, the heat-sensitive adhesive exposed to the interior of the mold cavity. 
     As depicted in FIG. 4, the surface of the ECL  10 , in particular, the base  12 , the booklet  16 , and the overlaminate are adhered to the container C without becoming integrated with the plastic of the container itself; however, as desired, the ECL itself; or any selected portions thereof, may be incorporated into the container. As a result, the ECL can be positioned so that its outermost surface, the overlaminate layer, is flush with the outer surface of the container. Alternatively as shown, the entire ECL may be substantially external to the container, thus having a raised configuration. While in the mold  50 , the heat activates the adhesive layer  14  on the rear surface of the base  12  causing the label  10  to be adhered to the container C. 
     As described above, because base layer  12  is in closer proximity container C, it is constructed so that it properly shrinks from the heat generated from the blow molding process that would otherwise ruin the aesthetics of the ECL, or worse, destroy the ECL by excessively shrinking or melting the base layer. Accordingly, the expanded content label may be subjected to elevated temperatures during the process of blow molding without incurring substantial deformation. 
     After the expanded content label has been sufficiently adhered to the blow-molded container, the mold is opened and the consequentially labeled container is ejected from the mold. 
     The above description is that of a preferred 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. Further, any reference to claim elements in the singular, for example, using the articles “a,” “and,” “the,” or “said,” is not to be construed as limiting the element to the singular. The claims are to be interpreted in accordance with the principles of patent law including the doctrine of equivalents.