Abstract:
A method of making a closure for a container is disclosed. The closure has a central panel surrounded by a plastic skirt. A utensil is attached to the skirt. The method includes providing a mold having a mold space that receives the central panel and defines the skirt and the utensil, positioning the panel within the mold space, injecting molten plastic into the mold space to form the skirt and the utensil, curing the plastic to form the closure and then removing the closure from the mold.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention concerns closures for containers, and especially closures for single serving foodstuff containers having utensils provided with the closure.  
       BACKGROUND OF THE INVENTION  
       [0002]     Foodstuffs such as yogurt, ice cream, cottage cheese and the like are conveniently packaged in containers holding a single serving size. The food in such containers is intended to be consumed directly from the container as a meal or a snack. The aforementioned food items are not conveniently eaten without utensils, however, and it is found troublesome to supply a utensil, such as a spoon, with the container.  
         [0003]     Separate utensils may be supplied along with the container at its point of purchase, or a separate utensil may be packaged on the outside of the container, but these measures do not reliably provide a utensil with a container. The utensils become separated and lost, or the supply of food containers exceeds the supply of utensils. If utensils are not supplied, the result is lost sales of a perishable product with limited shelf life.  
         [0004]     Attempts have been made in the past to integrally mold utensils into container closures. However, such solutions have largely been confined to homogeneous plastic closures and are not readily applicable to composite closures formed of a central paperboard panel surrounded by a plastic skirt. Composite closures are in widespread use for their ability to be substantially sealingly re-closed after opening. Furthermore, composite closures are advantageous because the paperboard panel in such closures provides a large surface area that may be printed with colorful indicia such as trademarks and illustrations identifying the product within the container.  
         [0005]     It would be advantageous to reliably provide a utensil, such as a spoon, with composite closures for containers, especially for use with single serving sized containers for foodstuffs.  
       SUMMARY OF THE INVENTION  
       [0006]     The invention concerns a closure for a container. In one preferred embodiment, the closure comprises a central panel formed from paperboard and bounded by a perimeter. The central panel has opposite side surfaces. A plastic skirt is attached to the central panel along the perimeter. The skirt extends substantially perpendicularly to the panel and thereby defines a well on one of the side surfaces. A release coating is preferably applied substantially over the one side surface, but a region is formed on the one side surface wherein the release coating is absent. A plastic utensil is removably attached to the central panel over the region having no release coating.  
         [0007]     The utensil may be a spoon, a knife, a fork or other implement. Preferably, the plastic is selected from the group consisting of polypropylene, polyethylene and polystyrene, although other materials are also feasible.  
         [0008]     The invention further includes a method of making a closure for a container. As described above, the closure includes a utensil and a plastic skirt surrounding a central panel. The method comprises the steps of:  
         [0009]     (A) placing the central panel within a mold;  
         [0010]     (B) injecting a plastic resin into the mold, the mold having a mold space defining the skirt and the utensil; and  
         [0011]     (C) removing the closure from the mold.  
         [0012]     The method may also include the step of adhering the utensil to the central panel. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]      FIG. 1  is a perspective view of a container with a composite closure according to the invention;  
         [0014]      FIG. 2  is a top perspective view of the closure shown in  FIG. 1 ; and  
         [0015]      FIG. 3  is a bottom perspective view of the closure shown in  FIG. 1 .  
     
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS  
       [0016]      FIG. 1  shows a perspective view of a container having a composite closure  12  according to the invention. Container  10  is preferably a single serving container holding foodstuffs such as ice cream. Closure  12  comprises a central panel  14 , preferably formed from paperboard. Paperboard is advantageous because it permits central panel  14  to be printed with multi-color indicia for the display of trademarks, illustrations, and other attention-getting devices to help distinguish the product within the container from among the many others with which it competes on the store shelf.  
         [0017]     Central panel  14  is surrounded by a plastic skirt  16  which is attached to the perimeter  18  of the panel. Skirt  16  is sized to engage the container  10  and form a seal between it and the closure  12 . Preferably, the composite closure  12  is formed by injection molding in a cavity and core mold. The mold is opened by removing the core from the cavity, and a pre-printed central panel  14  is placed therein. The mold is then closed by inserting the core into the cavity, the cavity and core having a predetermined mold space defining the skirt  16 .  
         [0018]     Molten plastic is injected into the mold space between the cavity and core to form the skirt  16 . A portion of the perimeter  18  of panel  12  extends into the mold space within the mold and is thereby engaged by the molten plastic upon injection. As shown in  FIG. 2 , the engagement of skirt  16  with perimeter  18  is advantageously accomplished by the use of a flange  20  that projects substantially perpendicularly from skirt  16  onto the outwardly facing surface  22  of central panel  14 . The outwardly facing surface  22  is treated so as to be compatible with the plastic forming the flange  20 , which adheres to the central panel  14  upon curing. Some plastic resins, such as polypropylene, will adhere directly to paperboard. It is also feasible to use a pre-printed paperboard coated with a thin layer of polypropylene to ensure good adhesion between the flange  20  and the central panel  14 . Other plastics, such as polyethylene and polystyrene may also be used to form skirt  16  and flange  20 .  
         [0019]      FIG. 3  shows a perspective view of the opposite side of the closure  12 . Skirt  16  extends away from the central panel  14  substantially perpendicularly to define a well  24  that faces the inside of the container  10  when the closure  12  is mounted thereon to close it. The container  10  is received within well  24 , the skirt  16  engaging the sidewall  26  of the container  10  as shown in  FIG. 1  to form a seal. The seal may be augmented by attaching a plastic or foil membrane across the opening of the container  10  between the central panel  12  and the container.  
         [0020]     With reference again to  FIG. 3 , a utensil  28  having an elongated handle  30  is molded with the skirt  16 . Utensil  28  is positioned within well  24  adjacent to the central panel  14  and will thus be protected on the inside of the container  10  when the closure  12  is in place thereon. In the example shown, the utensil is a spoon, as would be appropriate for a container holding ice cream or yogurt, to be consumed by the purchaser directly from the container. However, the utensil could also be a knife, as would be appropriate if the container contents were, for example, cream cheese to be spread on another food item. The utensil would be a fork if the container held solid food matter. To augment the stiffness of the utensil it is preferred to form it from polypropylene or polystyrene.  
         [0021]     The core of the cavity and core mold has a mold space defining the utensil  28 . One surface of this mold space is bounded by the central panel  14  when it is placed in the mold. A gate is positioned between the aforementioned mold space defining the skirt  16  and the mold space defining the utensil  28  to provide fluid communication between these spaces, allowing the molten plastic to flow under pressure into both mold spaces to mold both the utensil and the skirt. Sprue  32  is formed in the gate between the mold spaces. The sprue is readily severable for ease of removal of the utensil  28  from the skirt  16 .  
         [0022]     The inwardly facing surface  34  of central panel  14  preferably has a release coating  36  thereon to prevent the utensil  28  from adhering to the central panel  14  substantially over the length of the utensil upon curing of the plastic resin. If the utensil  28  is allowed to adhere lengthwise to the central panel  14 , or even at spaced locations along the utensil&#39;s length, it will cause the panel to warp because the plastic comprising the utensil shrinks upon curing. The release coating  36  may comprise a layer of varnish or polyester, which is preferably pre-printed or coated onto the surface  34 . Attachment of the utensil  28  to the closure  12  is effected by providing a relatively small region  38  on surface  34  of the central panel  14  that does not have a release coating. Region  38  is preferably positioned at or near the end of handle  30  and allows a portion of the utensil to adhere to the inwardly facing surface  34  upon molding of the utensil and the skirt. This prevents the utensil  28  from becoming detached from the closure  12  during manufacturing, handling and assembly. It also prevents the utensil from contacting the food item within the container during shipment and storage. Significant distortion of the central panel  14  is avoided by attaching the handle  30  to the central panel over a relatively small area substantially adjacent to the skirt  16 .  
         [0023]     Container closures according to the invention provide a composite closure having a utensil and are advantageously used with single serving containers to allow the food therein to be consumed directly out of the container.