Patent Publication Number: US-2015069063-A1

Title: Container lid with ring and method of manufacture

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Application claims priority to U.S. Provisional Patent Application Ser. No. 61/876,067, filed on Sep. 10, 2014, to Keegan Y. Yang et al. entitled “Molded Fiber Lid with Plastic Ring and Method of Manufacture,” currently pending, the entire disclosure of which is incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Containers for food products are well known in the art. Such containers typically include a base and a lid. The lid may be attached to the base in various manners. However, such previously known container lids are not without shortcomings. For example, in recent years, continuing efforts have been made to increase the recyclability of packaging, and in particular, food packaging Previously known container lids made of multiple materials (e.g., paperboard and plastic) have not been recyclable due to containing such multiple materials and have therefore, upon disposal, been placed in waste that is directed for landfills. 
     Accordingly, a need exists for a lid made of multiple materials that can be separated so that the various different materials can be recycled or composted apart from one another. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention is directed to a container lid adapted for interlocking attachment with a container base, wherein the lid comprises a lid insert constructed of a paper-based material (e.g., molded fiber, pressed paperboard, etc.) and a peripheral ring constructed of a different material (e.g., plastic). The ring is configured to be easily separable from the lid insert upon disposal of the lid. The lid insert may comprise a central cover portion and a generally flat and horizontal peripheral rim extending outwardly around at least part of the cover portion. The cover portion of the lid insert can include an upwardly projecting central section, which may be generally dome-shaped in one embodiment. 
     The ring circumscribes at least part of the lid insert&#39;s rim and includes a horizontal outwardly extending flange and a skirt depending downwardly from the flange. A first undercut or locking projection extends inwardly from the skirt. The first locking projection may be in the form of a single projection that extends substantially continuously around the entire interior periphery of the skirt or may be in the form of a plurality of peripherally-spaced projections having gaps therebetween. A first channel is defined between the first locking projection and a bottom surface of the ring&#39;s flange. The channel is sized and shaped to receive an outer edge of the lid insert&#39;s rim so as to releasably retain the lid insert&#39;s rim between the first locking projection and the bottom surface of the flange. In one embodiment, the channel is sized and shaped to receive both the outer edge of the lid insert&#39;s rim and an outer edge of a peripheral rim extending around the base. 
     In another embodiment, the ring includes first and second undercuts or locking projections extending inwardly from the skirt, wherein the second locking projection is located beneath the first locking projection. In this embodiment, a first channel is defined between the first locking projection and the bottom surface of the lower flange, and a second channel is defined between the second locking projection and the first locking projection. The first channel is sized and shaped to receive an outer edge of the lid insert rim, while the second channel is sized and shaped to receive an outer edge of the base rim. It will be appreciated that the ring may be injected molded either directly onto the lid insert or may be injected molded and then combined with the lid insert. Alternatively, the ring may be thermoformed and then combined with the lid rim. 
     In a further embodiment, the ring has a stepped cross section. In that embodiment, the ring may include a generally horizontal and outwardly extending upper flange, an upper skirt extending downwardly from the upper flange, a generally horizontal lower flange extending outwardly from the upper skirt, and a lower skirt extending downwardly from the lower flange. A first undercut or locking projection extends inwardly from the upper skirt and one or more second locking projections extend inwardly from the lower skirt, optionally at various heights about the lower skirt. A first channel is defined between the first locking projection and a bottom surface of the upper flange. A second channel is defined between at least one of the second locking projections and a bottom surface of the lower flange. A third channel may be defined between two or more of the second locking projections. 
     Another aspect of the present invention is directed to a method of manufacturing the lid. In the method, a paper-based material is formed into a lid insert having a peripheral rim. In one embodiment of the method, the ring may be injection molded directly around at least a portion of the lid insert rim. In another embodiment of the method, the ring may be injection molded separately from the lid insert and then subsequently combined with the lid insert. In a further embodiment of the method, the ring may be thermoformed separately from the lid insert and then subsequently combined with the lid insert. 
     Other aspects and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments and the accompanying drawing figures. 
    
    
     
       DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
       In the accompanying drawing, which fowls a part of the specification and is to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views: 
         FIG. 1  is a side perspective view of a container assembly comprising a lid insert, a base and a ring attaching the lid insert to the base in accordance with one embodiment of the present invention; 
         FIG. 2  is an enlarged partial sectional side perspective view of a container assembly comprising a lid insert, a base and a ring securing the lid insert with the base, wherein the ring includes two undercuts located at different heights in accordance with a first embodiment of the present invention; 
         FIG. 3  is a side perspective view of a lid insert and ring in accordance with one embodiment of the present invention, wherein the ring is attached to the lid insert; 
         FIG. 4  is a side perspective view of a lid insert and ring in accordance with one embodiment of the present invention, wherein the ring is detached from the lid insert; 
         FIG. 5  is an enlarged partial sectional side perspective view of a container assembly comprising a lid insert, a base and a ring securing the lid insert with the base, wherein the ring includes a single undercut in accordance with a second embodiment of the present invention; 
         FIG. 6  is an enlarged partial sectional outer side perspective view of a container assembly comprising a lid insert, a base and a ring securing the lid insert with the base, wherein the ring includes a plurality of undercuts at various heights in accordance with a third embodiment of the present invention; and 
         FIG. 7  is an enlarged partial sectional inner side perspective view of the container assembly of  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. For purposes of clarity in illustrating the characteristics of the present invention, proportional relationships of the elements have not necessarily been maintained in the drawing figures. 
     The following detailed description of the invention references specific embodiments in which the invention can be practiced. The embodiments are intended to describe aspects of the invention in sufficient detail to enable those skilled in the art to practice the invention. Other embodiments can be utilized and changes can be made without departing from the scope of the present invention. The present invention is defined by the appended claims and the description is, therefore, not to be taken in a limiting sense and shall not limit the scope of equivalents to which such claims are entitled. 
     The present invention is directed generally to a container assembly  10  comprising a lid  12  adapted for interlocking placement over a receptacle or base  14 , wherein the lid  12  includes a lid insert  16  and circumscribing ring  18 . The lid  12  is adapted for being removably attached to the container base  14 . As discussed in greater detail below, the ring  18  facilitates attachment of the lid  12  to the container base  14 . In one embodiment, the lid insert  16  may be constructed of a recyclable or compostable material, such as molded fiber or pressed paperboard for example, and the ring  10  may be constructed of a recyclable plastic. 
     The ring  18  is designed to be easily and cleanly separated from the lid insert  16  by a consumer, such that the base  14 , lid insert  16  and ring  18  can be all be separately recycled or composted upon disposal. In that regard, as discussed in more detail below, the ring  18  may include one or more undercuts, ribs, barbs, lugs or projections to facilitate mechanical attachment to the lid insert  16  and base  14  without the use of any adhesive bond. Each of these three components (i.e., the base  14 , lid insert  16  and ring  18 ) will be discussed in further detail below. 
     Referring to the figures,  FIG. 1  illustrates a side perspective view of one embodiment of the container assembly  10 . As shown in  FIGS. 1 and 2 , the lid  12  includes a lid insert  16  having an upwardly projecting central cover portion  22  and a horizontal peripheral rim  24  extending radially and outwardly at least partially or fully around the cover portion  22 . The lid insert  16  is sized and shaped to generally cover at least a portion of the base  14 . The lid insert  16  may take form in a variety of shapes, including round, square, oval, rectangular or other suitable shapes. In one embodiment, the cover portion  22  of the lid insert  16  is generally dome-shaped. However, it will be appreciated that the cover portion  22  need not be dome-shaped and may take on any other suitable shape. The cover portion  22  and rim  24  of the lid insert  16  may be integrally formed of any suitable material, including but not limited to a cellulosic or fiber-containing material, a paper-based material, a plastic material, a metallic material or any other suitable material now known or hereafter developed. In one preferred embodiment, the lid insert  16  is constructed of a recyclable or compostable material, such as molded fiber or paperboard. The lid insert  16  may be produced in a process that results in a generally flat rim  24  or in a process that results in a variable, wavy or bowed rim  24 . 
     The terms “paper” or paper-based” as used herein, are broad terms and include without limitation all types of paper products, such as paperboard, kraft paperboard, reprocessed paperboard, molded paper, cellulosic fiber, molded fiber, pulp slurry, corrugated paper, cardboard, coated paper, paper laminates and multi-ply paper. The term “pulp slurry,” as used herein, is a broad term and includes without limitation an aqueous slurry containing cellulose or cellulosic fiber derived from a plant or wood pulping process or paper recycling process. The term “pressed paperboard,” as used herein, is a broad term and includes without limitation paper that is constructed from a generally planar paperboard blank and deformed into shape under pressure. In an embodiment wherein the lid insert  16  is formed of pressed paperboard, generally radial score lines may be formed in the paperboard blank prior to the blank being formed into shape. The blank can then be formed into shape by a forming press that includes upper and lower heated dies having corresponding male and female surfaces. During the forming process, pleats may be formed at the score lines. 
     The lid insert  16  may further include printing or other graphics on an exterior surface of the cover portion  22 . One or more of the inside and outside surfaces of the lid insert  16  may be coated with a polymeric coating, a polymeric film or another material or liner suitable for impeding liquids or moisture from penetrating therethrough. 
     The container base  14 , to which the lid  12  may be releasably attached, may take any suitable shape and may be in the form of a bowl, carton, box, tray, cup or other receptacle. Like the lid insert  16 , the container base  14  can be constructed of any suitable material, including but not limited to a cellulosic or fiber-containing material, a paper-based material, a plastic material, a metallic material or any other suitable material now known or hereafter developed. One or more of the inside and outside surfaces of the container base  14  may be coated with a polymeric coating, a polymeric film or another material or liner suitable for impeding liquids or moisture from penetrating therethrough. In one preferred embodiment, the container base  14  is constructed of a recyclable or compostable material, such as molded fiber or paperboard. The container base  14  may be produced in a process that results in a generally flat rim  20  or in a process that results in a variable, wavy or bowed rim  20 . 
     As shown in  FIG. 2 , one embodiment of the container base  14  includes a generally flat and horizontal peripheral rim  20  extending radially and outwardly at least partially or fully therearound that corresponds generally to the rim  24  of the lid insert  16 . When the lid insert  16  is attached to or is otherwise covering the container base  14 , the rim  24  of the lid insert  16  at least partially mates with the rim  20  of the container base  14 . The lid insert&#39;s rim  24  may include a circumscribing outer edge  38  that is generally identical or similar in size and/or shape to a circumscribing outer edge  40  of the container base&#39;s rim  20 . Like the lid insert  16 , the base  14  may take form in a variety of shapes, including round, square, oval, rectangular or other suitable shapes. In fact, in one optional embodiment, the lid insert  16  is generally identical to the container base  14 . In other words, the lid insert  16  may simply be an inverted or overturned container base  14 , both of which may be constructed of a pressed paperboard material or a molded fiber material, for example. In such an embodiment, the lid insert  16  may be a mirror image of, and interchangeable with, the container base  14 . 
     Turning attention now to the ring  18 , it will be understood that the ring  18  may be constructed of a recyclable material, such as a plastic material, polymeric material, molded fiber material, metallic material or other suitable material now known or hereafter developed. The ring  18  may be formed in an injection molding process or a thermoforming process. The ring  18  may circumscribe all or a portion of the lid insert&#39;s rim  24 . 
     A first embodiment of the ring  18  is illustrated in  FIG. 2 . In that embodiment, the ring  18  includes a generally horizontal flange  26  and a downwardly extending skirt  28 . As shown, the ring  18  can include upper and lower inwardly extending locking projections or undercuts  30 ,  32 . The undercuts  30 ,  32  may be in the form of ribs, barbs, lugs or other projections. The undercuts  30 ,  32  may each be in the form of a single projection that extends substantially continuously around the entire interior periphery of the skirt  28  or may include a plurality of peripherally-spaced projections having gaps therebetween where no projection is present. As depicted, an upper channel  34  is formed between the top side of the upper undercut  30  and the bottom surface of the ring&#39;s flange  26 . A lower channel  36  is formed between the top side of the lower undercut  32  and the bottom side of the upper undercut  30 . As demonstrated in  FIG. 2 , the outside edge  38  of the lid insert&#39;s rim  24  snaps into the upper channel  34  and is retained in the upper channel  34  so as to releasably lock the ring  18  to the lid insert  16 . Similarly, the outside edge  40  of the base&#39;s rim  20  snaps into the lower channel  36  and is retained in the lower channel  36  so as to releasably lock the ring  18  to the base  14 . As such, the ring  18  releasably locks the lid insert  16  to the base  14 . Put differently, the lid insert  16  and base  14  may be in snapping engagement with one another via the ring  18 . When a consumer desires to gain access to the contents (e.g., food) within the base  14 , the consumer may grasp a lower portion  42  of the ring&#39;s skirt  28  and simultaneously pull outwardly and upwardly in order to disengage the outer edge  40  of the base&#39;s rim  20  from the ring&#39;s lower channel  36 . The outer edge  38  of the lid insert&#39;s rim  24  may also optionally be disengaged from the ring&#39;s upper channel  34  during this process or may otherwise remain engaged in the upper channel  34 . 
     A second embodiment of the ring  18  is illustrated in  FIG. 5 . The second embodiment is similar in nature to the first embodiment (shown in  FIG. 2 ), except for that the second embodiment includes only a single locking projection or undercut  44 . The undercut  44  may be in the form of ribs, barbs, lugs or other projections. The undercut  44  may be in the form of a single projection that extends substantially continuously around the entire interior periphery of the skirt  28  or may include a plurality of peripherally-spaced projections having gaps therebetween where no projection is present. A single channel  46  is formed between the top side of the undercut  44  and a bottom surface of the ring&#39;s flange  26 . As demonstrated in  FIG. 5 , the outer edge  38  of the lid insert&#39;s rim  24  and the outer edge  40  of the base&#39;s rim  20  may both be retained in the channel  46  so as to releasably lock the lid insert  16  to the base  14  via the ring  18 . When a consumer desires to gain access to the contents (e.g., food) within the base  14 , the consumer may grasp a lower portion  42  of the ring&#39;s skirt  28  and simultaneously pull outwardly and upwardly in order to disengage the outer edge  40  of the base&#39;s rim  20  from the ring&#39;s channel  46 . The outer edge  38  of the lid insert&#39;s rim  24  may also optionally be disengaged from the ring&#39;s channel  46  during this process or may otherwise remain engaged in the channel  46 . 
       FIGS. 6 and 7  demonstrate a third embodiment of the present invention. In that embodiment, the ring  18  has a stepped cross section. The ring  18  may include a generally horizontal and outwardly extending upper flange  48 , a downwardly extending upper skirt  50 , a generally horizontal and outwardly extending lower flange  52 , and a downwardly extending lower skirt  54 . In this embodiment, the periphery of the lid insert&#39;s rim  24  may be smaller than the periphery of the base&#39;s rim  20 . 
     As depicted, the upper skirt  50  may include one or more inwardly extending locking projections or undercuts  56  and the lower skirt  54  may include one or more inwardly extending locking projections or undercuts  58 . The undercuts  56 ,  58  may be in the form of ribs, barbs, lugs or other projections. The undercuts  56 ,  58  may each be in the form of a single projection that extends substantially continuously around the entire interior periphery of their respective skirts  50 ,  54  or may include a plurality of peripherally-spaced projections having gaps therebetween where no projection is present. In one embodiment, the undercuts  58  of the lower skirt  54  may be positioned at various heights. Likewise, while not shown, the undercuts  58  of the upper skirt  50  may also be position at various heights. 
     In the same general manner as the embodiments described above, a channel is formed between the top side of each undercut  56  and the bottom surface of the ring&#39;s upper flange  48 , wherein the channel is suitable for receiving the outer edge  38  of the lid insert&#39;s rim  24  therein for releasably locking the ring  18  to the lid insert  16 . Similarly, a plurality of channels are formed between the top side of undercuts  58  and the bottom side of other undercuts  58  and/or the bottom surface of the ring&#39;s lower flange  52 , wherein such channels are suitable for receiving the outer edge  40  of the base&#39;s rim  20  therein for releasably locking the ring  18  to the base  14 . As demonstrated best in  FIG. 7 , this embodiment is particularly beneficial in retaining the ring  18  to a wavy base rim  20 . Specifically, as depicted best in  FIG. 7 , multiple channels are formed at various heights about the lower skirt  54 , whether formed between the undercuts  58  and the bottom surface of the lower flange  52  or formed between two or more of the undercuts  58 , thereby permitting the base rim  20  to be captured in a channel regardless of variations in its height due to its waviness. 
     It will be appreciated that the skirts  28 ,  50 ,  54  of the various ring  18  embodiments discussed above may be slightly outwardly flared in order to guide and center the ring  18  with respect to the lid insert  16  and base  14 . Further, the undercuts  30 ,  32 ,  44 ,  56 ,  58  may be made in other various shapes and depths to adjust the ring&#39;s degree of hold, ease of insertion and ease of removal. The undercuts  30 ,  32 ,  44 ,  56 ,  58  can have ramped or chamfered bottoms sides in order to facilitate the ring&#39;s  18  attachment to the lid insert  16  and base  14 . 
     In all of the above-referenced embodiments, the plastic ring  18  is such that it can be attached to the lid insert  16  during use (see  FIG. 3 ) and then easily and cleanly separated from the lid insert  16  by a consumer after use (see  FIG. 4 ), so that a paper-based lid insert  16  and plastic ring  18  can be separately recycled or composted separately upon disposal. 
     As described above, the undercuts  30 ,  44 ,  56  are designed to bite and hold the lid insert&#39;s rim  24  strongly enough that the ring  18  will stay in position through the consumer&#39;s end use. However, since the ring  18  is preferably not glued or melted to the lid insert  16 , the consumer can very easily remove or punch the lid insert  16  from the ring  18 , such that the two components are separated for disposal. The lid insert  16  and the base  14  may be placed in one recycle bin, while the plastic ring  18  may be placed in a separate recycle bin. Alternatively, each of the three components may be placed in their own dedicated recycle bins so that paperboard, molded fiber and plastic materials are all separate from one another. 
     Turning now to the method of manufacture, in one embodiment, the lid insert  16  is formed in a molding or press process and then placed into an injection molding machine. The plastic ring  18  may be formed around the lid insert&#39;s rim  24  and particularly around its outer edge  38  to form the lid  12 . When formed, the undercuts  30 ,  44 ,  56  of the ring  18  entrap the rim&#39;s outer edge  38 . 
     In another embodiment, the lid insert  16  and ring  18  are formed in separate processes. For example, the lid insert  16  may be formed in a fiber molding process or a paperboard pressing process, whereas the ring  18  may be formed in a thermoforming process or an injection molding process and then combined with the lid insert  16  by an automated machine to form the lid  12 . The thermoforming process may result in a cost savings over the injection molding process. Once complete, the lids  12  may be kept separate from the bases  14  until a product (e.g., food) is placed in the bases  14 . At that time, the lids  12  may be snappingly engaged with the bases  14  to cover and contain the contents within the bases  14 . 
     From the foregoing, it will be seen that this invention is one well adapted to attain all the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure. It will be understood that certain features and sub combinations are of utility and may be employed without reference to other features and sub combinations. This is contemplated by and is within the scope of the claims. Since many possible embodiments of the invention may be made without departing from the scope thereof, it is also to be understood that all matters herein set forth or shown in the accompanying drawings are to be interpreted as illustrative and not limiting. 
     The constructions described above and illustrated in the drawings are presented by way of example only and are not intended to limit the concepts and principles of the present invention. Thus, there has been shown and described several embodiments of a novel invention. As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the examples illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. The terms “having” and “including” and similar terms as used in the foregoing specification are used in the sense of “optional” or “may include” and not as “required”. Many changes, modifications, variations and other uses and applications of the present construction will, however, become apparent to those skilled in the art after considering the specification and the accompanying drawings. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention which is limited only by the claims which follow.