Patent Grant
8870015
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.
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.
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.
In the drawings:
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.
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.
As perhaps best shown in the cutaway view of
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.
As perhaps best shown in the cutaway view of
As perhaps best shown in the cutaway view of
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.
As perhaps best shown in the cutaway view of
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' 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'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's forming methods for a pulp part can'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.
This application is a continuation of application Ser. No. 13/551,377 filed Jul. 17, 2012, the disclosure of which is incorporated by reference.
| Number | Name | Date | Kind |
|---|---|---|---|
| 3550832 | Fitzgerald | Dec 1970 | A |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 13551377 | Jul 2012 | US |
| Child | 13844667 | US |
