Abstract:
A hybrid thermoformed/pulp container comprising a pulp tray with a rim that includes an ear; and a thermoformed frame with a rib that includes a protrusion, wherein the pulp tray can be attached to the thermoformed frame by snapping the ear into position above the protrusion. Alternative embodiments of the invention include a kit for building the hybrid container, and a method of assembling the hybrid container.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of application Ser. No. 13/551,377 filed Jul. 17, 2012, the disclosure of which is incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to the field of containers. More particularly, the present invention relates to hybrid containers made with a combination of pulp-type materials and thermoformed plastic. 
     BACKGROUND OF THE INVENTION 
     Consumers increasingly prefer products which reflect their own values. Products made or packaged using materials that are recyclable and/or renewable, for example, may be perceived as being environmentally friendly. A coffee cup that is made from a recyclable material may demonstrate a cultural value that reinforces customer loyalty. For all of those reasons, and many more, use of recyclable or renewable materials will continue to grow. 
     One important recyclable and renewable material is paper pulp which is renewable, recyclable, and can even be compostable. Pulp can be formed into many different shapes, from the humble egg carton to containers with a smooth finish closely resembling plastic. However, unlike more resilient materials like thermoformed plastic, paper pulp tends to lose its rigidity and structural integrity very quickly when subjected to mechanical deformation as may occur during ordinary handling. 
     Thermoformed plastic containers are well known as inexpensive and highly customizable containers for the sale of a wide variety of products, everything from cell phones to deli meats. Thermoformed plastic containers are typically made from petroleum that may often be recyclable, but is generally not renewable or compostable. 
     Simple hybrid containers that combine thermoformed plastic components with pulp components are also known. For example, plastic lids are commonly used along with pulp cups for coffee. Injection molded hybrid containers, which require assembly in an injection molder are also known. This type of container combines injection molded plastic formed around a molded fiber/paper part to form a permanently bonded part. 
     What is needed is a hybrid container that can combine both pulp and thermoformed plastic components to maximize renewable and/or recyclable content while maintaining the structural and functional advantages of thermoformed plastic. 
     SUMMARY OF THE INVENTION 
     A first embodiment of the invention is a hybrid thermoformed/pulp container comprising a pulp tray with a rim that includes an ear; and a thermoformed frame with a rib having inside and outside walls, with the outside wall including a protrusion, wherein the pulp tray can be attached to the thermoformed frame by snapping the ear into position above the protrusion in the interior of the rib. 
     A second embodiment of the invention is a hybrid thermoformed/pulp container kit comprising a pulp tray with a rim that includes an ear; and a thermoformed lid with a side wall that includes a a protrusion, wherein the pulp tray can be attached to the thermoformed lid by snapping the ear into position above the protrusion. 
     A third embodiment of the invention is a method of forming a hybrid container comprising the steps of (A) providing a pulp tray with a rim that includes an ear; (B) providing a thermoformed lid with a side wall that includes a protrusion; (C) engaging the rim of the pulp tray with the side wall of the thermoformed lid; and (D) snapping the ear into position above the protrusion. 
     A hybrid container according to the invention can be shipped or stored with its components separately nested to conserve space. A retailer or end user can assemble it in the field, with no specialty machinery required. An end user or recycling facility can separate pulp content from plastic content for separate recycling streams. A hybrid container according to the invention can also increase the proportion of recyclable or even compostable or biodegradable content. 
     Further objects, features, and advantages of the invention will be apparent from the following detailed description when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIGS. 1A ,  1 B,  1 C, and  1 D are perspective, top, first side, and second side views, respectively, of a pulp tray for a container according to the invention; 
         FIGS. 2A ,  2 B and  2 C are perspective, top, and side views, respectively, of a thermoformed hinged lid for a container according to the invention; 
         FIGS. 3A and 3B  are perspective views of a hybrid container with a hinged lid according to the invention, with the lid in a closed position in  FIG. 3A  and with the hinged lid in an open position in  FIG. 3B ; 
         FIGS. 3C ,  3 D, and  3 E are top, first side, and second side views, respectively, of the container of  FIG. 3A ; 
         FIGS. 4A ,  4 B,  4 C, and  4 D are perspective, top, first side, and second side views, respectively, of a thermoformed collar for a container according to the invention; 
         FIGS. 5A ,  5 B,  5 C, and  5 D are perspective, top, first side, and second side views, respectively, of a first thermoformed cover for a container according to the invention; 
         FIGS. 6A and 6B  are perspective views of a hybrid container with a pulp tray, a thermoformed collar, and a separable thermoformed cover according to the invention, with the thermoformed cover positioned on the collar to form a closed container in  FIG. 6A  and with the thermoformed cover separated from the collar to expose the interior of the tray in  FIG. 6B ; 
         FIGS. 6C ,  6 D, and  6 E are top, first side, and second side views, respectively, of the container of  FIG. 6A ; 
         FIGS. 7A ,  7 B,  7 C, and  7 D are perspective, top, first side, and second side views, respectively, of a pulp cover for a container according to the invention; 
         FIGS. 8A and 8B  are perspective views of a hybrid container with a pulp tray, a thermoformed collar, and a separable pulp cover according to the invention, with the pulp cover positioned on the collar to form a closed container in  FIG. 8A  and with the pulp cover separated from the collar to expose the interior of the tray in  FIG. 8B ; 
         FIGS. 8C ,  8 D, and  8 E are top, first side, and second side views, respectively, of the container of  FIG. 8A ; 
         FIGS. 9A ,  9 B,  9 C, and  9 D are perspective, top, first side, and second side views, respectively, of a second thermoformed cover for a container according to the invention; 
         FIGS. 10A and 10B  are perspective views of a hybrid container with a pulp tray and a separable thermoformed cover according to the invention, with the thermoformed cover positioned on the pulp tray to form a closed container in  FIG. 10A  and with the thermoformed cover separated from the pulp tray to expose the interior of the tray in  FIG. 10B ; and 
         FIGS. 10C ,  10 D, and  10 E are top, first side, and second side views, respectively, of the container of  FIG. 10A . 
         FIG. 11A  is a cross-section of the pulp tray  10  and thermoformed collar  110  positioned for engagement,  FIG. 11B  is a cross section of the container  150  taken along the line  11 B- 11 B in  FIG. 6B , and  FIG. 11C  is a cross section of the container  350  taken along the line  11 C- 11 C in  FIG. 10A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1A ,  1 B,  1 C, and  1 D are perspective, top, first side, and second side views, respectively, of a pulp tray  10  for a container according to the invention. As perhaps best shown in  FIG. 1B , the pulp tray  10  includes a cavity floor  11  surrounded by cavity floor side wall corners  12 . Cavity side walls  13  extend upward from the cavity floor side wall corners  12 , forming a cavity  14  with cavity corners  16 . 
     The cavity side walls  13  terminate in a cavity rim  15  around the cavity  14 , and may include cavity corners  16 . The cavity rim  15  includes a pulp tray peripheral flange  17 , which may include one or more pulp tray flange ears  18  formed as relatively wide portions of the peripheral flange  17 . However this is not required, and the entire peripheral flange  17  may be of uniform width. 
       FIGS. 2A ,  2 B and  2 C are perspective, top, and side views, respectively, of a thermoformed hinged lid  20  for a container according to the invention. As perhaps best shown in  FIG. 2B , the thermoformed hinged lid  20  includes a hinged frame  30  with a hinge  21  that allows a hinged cover  40  to swing in and out of position on the frame  30 , to cover or uncover a hinged frame opening  22 . 
     The hinged frame  30  includes a convex hinged frame rib  31  that surrounds the hinged frame opening  22 . The rib  31  has hinged frame inside walls  32  terminating in hinged frame inside flanges  33  that surround the hinged frame opening. The hinged frame rib  31  has outside walls  34  that terminate in peripheral flanges  37 , which may include one or more flange ears  39 . The hinged frame inside walls  32  and hinged frame outside walls  34  meet at a hinged frame rib peak  36  that forms the upper surface of the rib  31 . 
     The hinged cover  40  includes a hinged cover central portion  41  extending to hinged cover side wall corners  42 . Hinged cover side walls  43  extend from the side wall corners  42  to a hinged cover peripheral flange  44 , which may include one or more hinged cover flange ears  46 . 
     The outside walls  34  of the hinged frame rib  31  include hinged frame outside wall exterior surface indents that form protrusions  35  extending into the rib interior region defined between the inside walls  32  and outside walls  34 . As explained in more detail below with respect to the exemplary container  50 , the protrusions  35  can engage with pulp tray flange ears  18  on a pulp tray  10 . The peripheral flange  37  of the frame  30  may include a hinged frame flange slot  38  for engagement with a hinged cover flange ridge  45  on the cover  40 . The slot  38  may be formed as a die cut hole, so that the slot  38  and ridge  45  together can form a friction latch to snap the cover  40  closed on the frame  30 . However, other snap closures could be used, for example an indentation could be used instead of a die cut hole, multiple latches could be used, or the positions of the slot and ridge could be swapped. 
     For purposes of illustration and not as a limitation, the names of the various portions of the pulp tray  10  and thermoformed hinged lid  20  (e.g. top, side, bottom, rear, etc.) assume that these pieces are positioned in an upright standing position with the cavity side of the tray facing up and the hinged lid positioned to mate with the tray. 
       FIGS. 3A and 3B  are perspective views of a hybrid container with a hinged lid  50 , comprising the tray  10  of  FIG. 1  and the thermoformed hinged lid  20  of  FIG. 2 .  FIG. 3A  shows the lid in a closed position, thereby forming a closed container with a first closed compartment  52 .  FIG. 3B  shows the hinged lid in an open position, thereby forming an open container with a first open compartment  51 .  FIGS. 3C ,  3 D, and  3 E are top, first side, and second side views, respectively, of the container of  FIG. 3A . 
     As perhaps best shown in the cutaway view of  FIG. 3A , the hybrid container with a hinged lid  50  is formed by snapping the thermoformed hinged lid  20  onto the pulp tray  10 . This is accomplished by engaging the rim  15  of the pulp tray  10  with the rib  31  of the thermoformed frame  30 , and pressing the pulp tray  10  into the frame  30  so that the ears  18  of the pulp tray  10  snap into position above the protrusions  35  on the thermoformed frame  30 . Although the exemplary container  50  includes ears  18  formed as widened portions of the flange  17 , this is not required. For example, the entire peripheral flange  17  may be of uniform width, without any ears, and any portion of that flange  17  can be snapped into position about the protrusions on the thermoformed frame. 
       FIGS. 4A ,  4 B,  4 C, and  4 D are perspective, top, first side, and second side views, respectively, of a thermoformed collar  110  for a container according to the invention. The thermoformed collar  110  includes a collar rib  113  that surrounds the collar opening  111  that has a collar opening periphery  112 . The collar rib  113  has collar inside walls  114  terminating in collar inside flanges  115  surrounding the collar opening  111 . The collar rib  113  has collar outside wall  116  that terminate in collar peripheral flanges  119 , which may include one or more flange ears (not shown). The collar inside walls  114  and collar outside wall  116  meet at a collar rib peak  118  that forms the upper surface of the collar rib  113 . 
     The collar outside walls  116  include one or more collar outside wall exterior surface indents that form corresponding bumps or protrusions  117  extending into the collar interior region defined between the inside walls  114  and outside walls  116 . As explained in more detail below with respect to the exemplary container  150 , the protrusions  117  can engage with a portion of the flange on a pulp tray  10 . 
       FIGS. 5A ,  5 B,  5 C, and  5 D are perspective, top, first side, and second side views, respectively, of a first thermoformed cover  120  for a container according to the invention. The thermoformed cover  120  has a thermoformed cover central portion  121  extending to thermoformed cover side wall corners  122 . Thermoformed cover side walls  123  extend from the thermoformed cover side wall corners  122  to a thermoformed cover peripheral flange  124 . 
       FIGS. 6A and 6B  are perspective views of a second hybrid container  150  with a pulp tray  10 , a thermoformed collar  110 , and a separable thermoformed cover  120  according to the invention.  FIG. 6A  shows the thermoformed cover  120  positioned on the collar, thereby forming a second closed compartment  152 .  FIG. 6B  shows the thermoformed cover separated from the collar to expose the interior of the tray and form a second open compartment  151 .  FIGS. 6C ,  6 D, and  6 E are top, first side, and second side views, respectively, of the second hybrid container  150  of  FIG. 6A . 
     As perhaps best shown in the cutaway view of  FIG. 6A , the second hybrid container  150  is formed by snapping the thermoformed collar  110  onto the pulp tray  10 . This is accomplished by engaging the rim  15  of the pulp tray  10  with the rib  113  of the thermoformed collar  110 , and pressing the pulp tray  10  into the thermoformed collar  110  so that the ears  18  of the pulp tray  10  snap into position above the protrusions extending into the interior of the thermoformed collar  110 . Once the thermoformed collar  110  is in place on the pulp tray  10 , the thermoformed cover  120  can be fitted onto the collar  110  with either a friction fit, or using an interference structure. 
       FIGS. 7A ,  7 B,  7 C, and  7 D are perspective, top, first side, and second side views, respectively, of a pulp cover  220  for a container according to the invention. The pulp cover  220  has a pulp cover central portion  221  extending to pulp cover side wall corners  222 . Pulp cover side walls  223  extend from the pulp cover side wall corners  222  to pulp cover peripheral flanges  224 . 
       FIGS. 8A and 8B  are perspective views of a third hybrid container  250  with a pulp tray  10 , a thermoformed collar  110 , and a separable pulp cover  220  according to the invention.  FIG. 8A  shows the pulp cover positioned on the collar  110 , thereby forming a third closed compartment  252 .  FIG. 8B  shows the pulp cover  220  separated from the collar  110  to expose the interior of the tray and form a third open compartment  251 .  FIGS. 8C ,  8 D, and  8 E are top, first side, and second side views, respectively, of the third hybrid container  250  of  FIG. 8A . 
     As perhaps best shown in the cutaway view of  FIG. 8A , the third hybrid container  250  is formed by snapping the thermoformed collar  110  onto the pulp tray  10 . This is accomplished by engaging the rim  15  of the pulp tray  10  with the rib  113  of the thermoformed collar  110 , and pressing the pulp tray  10  into the thermoformed collar  110  so that the ears  18  of the pulp tray  10  snap into position above the protrusions on the thermoformed collar  110 . Once the thermoformed collar  110  is in place on the pulp tray  10 , the pulp cover  220  can be fitted onto the collar  110 . 
       FIGS. 9A ,  9 B,  9 C, and  9 D are perspective, top, first side, and second side views, respectively, of a second thermoformed lid  320  for a container according to the invention. The thermoformed lid  320  has a thermoformed lid central portion  321  extending to thermoformed lid side wall corners  322 . Thermoformed lid side walls  323  extend from the thermoformed lid side wall corners  322  to thermoformed lid peripheral flanges  325 . 
     The thermoformed lid side walls  323  include one or more thermoformed lid side walls exterior surface indents that form corresponding bumps or protrusions  324  extending from the interior surface of those side walls  323 . 
       FIGS. 10A and 10B  are perspective views of a fourth hybrid container  350  with a pulp tray  10  and a separable second thermoformed lid  320  according to the invention.  FIG. 10A  shows the second thermoformed lid  320  positioned on the pulp tray  10 , thereby forming a third closed compartment  352 .  FIG. 10  B shows the second thermoformed lid  320  separated from the pulp tray  10  to expose the interior of the tray, thereby forming a third open compartment  351 .  FIGS. 10C ,  10 D, and  10 E are top, first side, and second side views, respectively, of the fourth hybrid container  350  of  FIG. 10A . 
     As perhaps best shown in the cutaway view of  FIG. 10A , the fourth hybrid container  350  is formed by snapping the thermoformed lid  320  onto the pulp tray  10 . This is accomplished by engaging the rim  15  of the pulp tray  10  with side walls  323  of the thermoformed lid  320 , and pressing the pulp tray  10  into the thermoformed lid  320  so that the ears  18  of the pulp tray  10  snap into position above the protrusions  324  on the thermoformed lid  320 . 
       FIG. 11A  is a cross-section of the pulp tray  10  and thermoformed collar  110  positioned for engagement, showing the ear or flange portion  18  extending horizontally from the rim of the pulp tray  10 . When the tray  10  and thermoformed collar  110  are engaged as shown in  FIG. 11B , the ear or flange portion may be bent downward from the rim at a relatively sharp angle to the horizontal. An angle of roughly 60 degrees, or between 45 and 75 degrees, between the cavity side wall  13  and the ear  18  facilitates bearing the vertical forces between the pulp tray  10  and the collar  110 , for example if the container is picked up by the collar  110 . A similar angle can be used in the container  350  as shown in  FIG. 11C . Although the exemplary flange  17  and ear  18  are shown as planar, this is not required and corrugations, die-cut wings that fold perpendicularly to the plane of the flange, or other 3D structures could be used to strengthen and increase the rigidity of the ear  18  or flange  17 . While a variety of dimensions could be used, a rib width A of about 0.17 inches, a protrusion-to-peak height B of about 0.17 inches, and an ear or flange width C of about 0.20 inches can be used. In general, the ear or flange width is chosen to be large enough to positively engage the protrusion after insertion into the rib, but small enough to clear the protrusion and snap into place during the insertion process. 
     While the preceding discussion of exemplary hybrid containers use particular embodiments of a pulp tray  10  and either a thermoformed hinged lid  20 , thermoformed collar  110 , or thermoformed cover  120 , the invention could be practiced with other tray and lid configurations. The exemplary pulp tray  10  includes a single internal cavity  14 , but this particular structure is not required. For example, a different number of cavities could be provided for particular applications, and the container as a whole or the individual cavities could be different sizes and/or shapes. 
     The thermoformed components of a hybrid container according to the invention can be made using conventional thermoforming methods, from any suitable thermoformable material. For example, a thermoformed hinged lid  20 , thermoformed collar  110 , or thermoformed cover  120  meant for use with ready-to-eat foods might be formed of a thermoformable plastic such as oriented polystyrene (OPS), talc-filled polypropylene (TFPP), polypropylene (PP), high impact polystyrene (HIPS), polyethylene terepthalate (PET), amorphous PET (APET), crystalline polyethylene (CPET) polystyrene copolymer blends, styrene block copolymer blends, and the like. 
     The pulp components of a hybrid container according to the invention can be made using conventional pulp container manufacturing methods, from any suitable pulp material. As used herein, the term pulp includes at least four industry-standard types of molded fiber products and associated manufacturing methods: (1) thick wall products primarily used for support packaging or plant, floral and nursery pots and containers, (2) transfer molded products commonly used for egg cartons or electronic product packaging, (3) thermoformed or thin-wall products dried in the mold to closely resemble thermoformed plastic material, or (4) processed molded fiber products that require some type of secondary or special treatment other than simply being molded and cured, such as die-cuts, perforations, printing, special slurry formulations, or embossments. However, the pulp components of a hybrid container according to the invention are preferably made using a thermoformed or thin-wall process. 
     A hybrid container according to the invention may include more than one thermoformed component, and the component or components may be formed of more than one material. Also, the components and materials are not necessarily homogeneous, but may be, for example, a laminate, co-extruded material, or multilayer material. 
     The exemplary thermoformed hinged lid  20 , thermoformed collar  110 , and thermoformed lid  320  include specific embodiments of indents that form protrusions able to engage with the ear of a pulp tray. While these exemplary structures show the protrusions at particular locations, this is not required and the protrusions could be located somewhere else. 
     In the exemplary thermoformed hinged lid  20 , thermoformed collar  110 , and thermoformed lid  320 , the indents on one side of a wall result in protrusions on the other side of the wall shaped as a shelf, rib, or ridge, convex when viewed from the protrusion side that will engage the ear. However, this exact structure is not required and the protrusion could have another male or convex structure such as a post, pin, plug, bulge, bump, hump, pyramid, cube, nub, projection, protrusion, protuberance, knob, or a combination of these structures. 
     Any of the thermoformed or pulp structures may also include additional special processing, such as one or more raised engravings or embossings for decorative or structural purposes, for example brand markings, informational messages, or decorations. 
     Additional components could be used in a hybrid container according to the invention. For example a plastic film or foil membrane barrier, sometimes referred to as “lid stock”, could be adhered, fastened, joined, thermally bonded, or otherwise positioned on the rim of a pulp tray  10 , to the peak of the thermoformed collar  110 , or to the peak of the hinged frame rib  36 , to cover the contents while allowing an optional thermoformed lid, collar, or cover to be fastened on the pulp tray, collar, or hinged frame. The lid stock can be made of the same r similar material as the lid, or it can be made of a different material. The lid stock may be imprinted, for example with brand names or product information before being applied to the pulp tray. The lid stock can, for example, provide tamper protection or otherwise protect the contents of the pulp tray. 
     This approach could be used, for example, to provide multiple refills (for wet wipes, baby wipes, food items, or other consumable products) in pulp trays, along with a single reusable thermoformed cover of the types shown in the present application. When the initial pulp tray has been emptied of its contents, a new refill pulp tray can be readied for use by peeling off the membrane barrier then snapping the tray on the thermoformed cover. The combination of a thermoformed collar with a rigid rib structure plus the pulp tray can provide an acceptably rigid structure for this kind of application. In contrast, a package made exclusively of pulp by itself may not be rigid enough to use, and would be more likely to fail during normal use. In this type of application, the hinged lid  20  or thermoformed collar  110  can provide rigidity whether or not the cover is on, and either a thermoformed or a pulp cover can be used with the thermoformed collar  110 . 
     While reusable wet wipes containers with refills are known, the reusable containers are generally formed entirely of plastic, for example as an injected molded tray along with a snap on collar/lid with hinged cover. Because this kind of product is formed entirely of injection molded plastic, a series of undercuts to attach lid to tray can be used. 
     As an explanation only and not as a limitation on the scope of the claims, it is believed that the present invention arises from the fact that todays&#39; forming methods for double-sided smooth pulp parts typically use two molds, an upper and a lower mold. Liquid bearing pulp material is introduced between the molds, then the liquid is drawn out as the molds are brought together to squeeze or coin the pulp together and form the part. Once the part has been formed, then the upper and lower molds are separated by moving the upper mold linearly relative to the lower mold. The upper and lower molds must be free to move relative to each other in this process, in particular they must be separable linearly. This requirement limits the shapes of the mold, in particular the mold can&#39;t include any undercuts and it must have positive draft. 
     In contrast, undercuts can be fabricated by thermoforming sheet plastic, for example to fabricate the protrusions  35  on the thermoformed hinged lid  20 , the protrusions  117  on the thermoformed collar  110 , and the protrusions  324  on the thermoformed lid  320 . In other words, pulp is different from plastic because today&#39;s forming methods for a pulp part can&#39;t make undercuts and therefore cannot make indents. A pulp mold can, however, form ears  18  as shown on the pulp tray  10 . A hybrid container according to the invention combines a thermoformed part that has indents with a pulp part that has ears for that reason. 
     It is understood that the invention is not confined to the embodiments set forth herein as illustrative, but embraces all such forms thereof that come within the scope of the following claims.