Patent Publication Number: US-2003226882-A1

Title: Corrugated paperboard dishware and cookware

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
     [0001] This non-provisional application claims the priority benefits of provisional U.S. patent application Ser. No. 60/377,825, filed on May 3, 2002. 
    
    
     
       FIELD OF THE DISCLOSURE  
       [0002] The disclosure generally relates to dishware and cookware and, more particularly, relates to disposable dishware and cookware.  
       BACKGROUND OF THE DISCLOSURE  
       [0003] Disposable dishware is widely used. For example, paper plates are ubiquitous at such events as picnics, barbecues and many other social gatherings. Paper cups are used for everything from in-home drinks to dentists offices to fast food restaurants. Milk cartons and restaurant take-out packages are often made of paper material coated with a fluid impermeable layer.  
       [0004] One difficulty associated with such items, however, is related to insulation. Taking a paper cup as an example, their use is somewhat limited when it comes to maintaining the temperature of the drink held therein. Coffee is often sold in disposable cups, but typically in the form of Styrofoam, or the like. Not only is it desirable to keep the contents warm and/or cold, but it is also desirable to limit dissipation of such temperature to the hand of the user. As a result, various after market devices have been introduced and been met with substantial commercial success. Foam coolers sized to correspond to the outer dimension of the cup are currently sold and provide a snug and insulative fit. Cardboard rings are often provided by coffee shops for fitting around the outside of the paper coffee cup to thereby provide an added barrier to limit heat transference to the hand of the users. However, both such solutions add additional apparatus to the process at both added expense and user burden.  
       [0005] Paper cookware is even more limited. As such items must be exposed to high temperatures, the paper is limited to applications which will not exceed its combustion point, approximately 450° F. Moreover, cookware such as pans and plates are often subjected not only to high temperatures, but below freezing temperatures as well. Paper is limited in this regard as well in that as the food contained within the dish freezes, it often expands due to the water contained therein, and the paper is of insufficient strength to withstand the forces of expansion. Ice cream cartons, for example, are therefore often oversized provided with reinforcing ribs or expansion joints to address such issues.  
       [0006] In light of the foregoing shortcomings, the use of paper in dishware and cookware has been less than fully exploited. Even though the paper itself is relatively inexpensive and lends itself to disposability and recycling, such limitations have prevented the breadth of disposable cookware options available to the consuming public, and required use of more expensive, and less than optimal, metals and the like.  
       SUMMARY OF THE DISCLOSURE  
       [0007] In accordance with one aspect of the disclosure, disposable paper based dishware and cookware are provided. The paper based dishware may be provided in the form of a cup formed from corrugated paperboard. The corrugations of the paperboard create voids which serve as an insulation layer between the user and the cup contents. The paper based cookware may be provided in the form of a pan formed from corrugated paperboard as well. The corrugation of the paperboard not only creates voids which may be filled with air or another insulating material, but also serve as cooling conduits or pseudo-chimneys enabling heat to dissipate from the paper to the air within the voids and ultimately to be directed away from the cookware.  
       [0008] In accordance with another aspect of the disclosure, an insulated food container is disclosed which comprises a bottom wall, and an upstanding outer wall attached to the bottom wall having an interior space. The outer wall includes an inner layer, an outer layer, and a corrugated layer between the inner layer and outer layer defining voids with the interior space being insulated from the atmosphere by the outer wall and the voids in the corrugated layer.  
       [0009] In accordance with another aspect of the disclosure, an insulated container manufactured from cellulosic materials is disclosed which comprises a bottom wall and an upstanding outer wall attached to the bottom wall in defining a mouth and an interior space. The outer wall includes a corrugated layer and at least one substantially planar layer attached to the corrugated layer. The corrugated layer includes a plurality of flutes forming voids in cooperation with the planar layer.  
       [0010] In accordance with another aspect of the disclosure, a method of cooking a food stuff is disclosed which comprises disposing a food stuff in a container manufactured in cellulosic materials, and warming the food stuff within the container. The container may include a bottom wall and upstanding outer wall with the outer wall including an inner layer, an outer layer, and a corrugated layer between the inner layer and the outer layer defining voids.  
       [0011] In accordance with yet another aspect of the disclosure, a method of evenly cooling a food stuff is disclosed which comprises disposing of food stuff within a container, placing the container in an atmosphere cooler than the temperature of the food stuff, and allowing the heat of the food stuff to dissipate within voids of the outer wall and to the atmosphere. The container may include an outer wall including an outer layer, an inner layer, and a corrugated layer between the inner layer and the outer layer defining the voids.  
       [0012] These and other aspects and features of the disclosure will become more apparent upon reading the following detailed descriptions when taken in conjunction with the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0013]FIG. 1 is an isometric view of a disposable cup constructed in accordance with the teachings of the disclosure;  
     [0014]FIG. 2 is an isometric view of a cap for the disposable cup.  
     [0015]FIG. 3 is an isometric view of the cup and cap assembled.  
     [0016]FIG. 4 is cross-sectional view of the cup of FIG. 1, taken along line  4 - 4  of FIG. 1;  
     [0017]FIG. 5 is an isometric view of a disposable pan constructed in accordance with the teachings of the disclosure;  
     [0018]FIG. 6 is a cross-sectional view of the pan of FIG. 3, taken along line  6 - 6  of FIG. 3; and  
     [0019]FIG. 7 is a cross-sectional view of an outer wall having more than one corrugated layer. 
    
    
     [0020] While the disclosure is susceptible to various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the disclosure to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the disclosure.  
     DETAILED DESCRIPTION OF THE DISCLOSURE  
     [0021] Referring now to the drawings, and with specific reference to FIGS.  1 - 3 , a disposable dish constructed in accordance with the teachings of the disclosure is generally referred to by reference numeral  20 . While the dish  20  is depicted in the form of a cup in FIG. 1, it is to be understood that dish could be provided in any other form wherein insulation properties are desirable such as, but not limited to plates, bowls, saucers, servers, casseroles, platters, and the like.  
     [0022] The cup  20  may include a frustoconical outer wall  22  closed by a base  24 . The outer wall  22  need not be frustoconical in shape but could be any number of other shapes including, but not limited to, straight conical, angular, or the like. The cup  20  may further include a brim  26  defining a mouth  28  for access to an interior space  30  for holding foodstuffs or drinks such a coffee, tea, soda, etc. The cup  20  may be provided with a lid  32  adapted to substantially close off the mouth  28  upon fitting to the cup, and which may include a relatively small port  34 , or reclosable flap (not shown) to allow for access to the liquid contained within the cup  20  when the lid  32  is mounted to the cup  20 .  
     [0023] Turning now to FIG. 4, the cup  20  is illustrated in cross-section. As shown therein, the outer wall  22  may be formed from corrugated paperboard. More specifically, the outer wall  22  may include an inner layer  36 , and outer layer  38 , and a layer  40  of corrugations or flutes  42  traveling longitudinally from the base  24  to the brim  26 . In so doing, the corrugations  42  form a plurality of voids  44 . The voids  44  may be filled with air which by itself serves as a temperature barrier or insulation layer inhibiting transfer of heat and/or cold from the interior space  30  to and from the atmosphere  46 . The voids  44  could, alternatively, be filled with some other insulative material such as, but not limited to, foam styrene, to further enhance the insulative properties of the cup  20 . The base  24  can also be formed of similar corrugated paperboard.  
     [0024] In further alternative embodiments, the outer wall  22  may include one or more additional layers of corrugated material to provide even more insulative capability. Such layers could be of various depth and spacing. The corrugations also could travel circumferentially around the cup  20 , as opposed to longitudinally. The various layers of corrugations could also be configured in differing or alternating orientations, or be provided at differing or alternating dimensions.  
     [0025] By manufacturing the cup  20  from corrugated paperboard, the cost of the cup  20  is maintained at sufficiently low level so as to be disposable. Moreover, the use of cellulosic material makes the cup easily recyclable. The use of corrugated paperboard affords a built-in insulation feature removing the need for aftermarket accessories such as coolers or slip-on protective coats.  
     [0026] As indicated above the use of corrugated paperboard is not limited to dishware according the teachings of this disclosure. Cookware and serveware are also encompassed. As illustrated in FIG. 3, the cookware may be provided as a pan  50 . While the following description will be made with reference to the pan  50 , it is to be understood that the terms cookware and serveware, and the teachings of this disclosure are applicable to many other forms including, but not limited to, pots, skillets, woks, griddles, casseroles, and the like.  
     [0027] The pan  50  may include a substantially rectangular outer wall  52  having a closed and substantially planar bottom wall  53 . The outer wall  52  may terminate at an upper end  54  with a radially outwardly extending lip  56 . The lip  56  defines a mouth  58  providing access to an interior space  60 . A lid  62  may be provided to close the pan  50  when desired. Moreover, the pan may include, while not depicted in FIG. 3, a plurality of partitions to divide the pan  50  into individual compartments. Such a feature may be particularly advantageous, for example, when heating or freezing a complete meal with an entree in one compartment and side dishes in others.  
     [0028] As shown in FIG. 4, wherein the pan  50  is depicted in cross-section, the construction of the pan  50  is similar to that of the cup  20 . More specifically, the outer wall  52  and bottom wall  53  may be constructed from corrugated paperboard. As with the cup  20 , the corrugated paperboard of the pan  50  may include an inner layer  64 , an outer layer  66 , and a layer  68  of corrugations  70  therebetween. The corrugations create voids  72  which may be filled with air or another insulative material. If the voids  72  are filled with air or some other thermally conductive material, the pan  50  is able to withstand temperatures significantly higher than normal paper products. Whereas normal paper combusts at approximately 451° F., the inventors have found that a pan  50  constructed in accordance with the teachings of the invention can withstand temperatures in excess of 500° F. In so doing, the pan  50  is able to withstand temperatures in excess of the majority of baking and cooking requirements of common dishes.  
     [0029] Not only can such a pan  50  withstand high temperatures and thus be microwavable or ovenable, such a pan  50  can also be chilled or frozen. This feature is provided, at least in part, by the additional room afforded by the voids  72  provided between the corrugations  70 . Such voids allow for the inner layer  64  to radially expand outwardly and compress the corrugations  70  into the voids  72  as the matter held within the pan  50  freezes and expands.  
     [0030] As with the dishware described above, the pan  50  may be alternatively provided with more than one layer of corrugations, or with corrugations of greater amplitude, frequency or wavelength. Moreover, the multiple layers of corrugations may be provided in alternating transverse directions, or at various degrees of out-of-phase disposition. Multiple grades of cellulosic material can also be used. In addition, if desired, the inner and/or outer layers, respectively, can be coated with liquid impervious, non-stick, or other compounds as well.  
     [0031] For example, as depicted in FIG. 7, an alternative embodiment of a dishware outer wall is depicted in cross-section. As shown therein, the outer wall  100  may include an inner layer  102 , an outer layer  104 , and an intermediate layer  106 , and first and second layers of corrugations  108  and  110  therebetween. Not only does the wall  100  include multiple layers of corrugations, but it will be further noted that the corrugations of the first and second layers  108  and  110  are provided in different dimensions. More specifically, the amplitudes, frequencies, and wavelengths of the corrugations are different. For example, the corrugations or flutes  112  of the first layer of corrugations  108  include a wavelength of β and amplitude of γ. Whereas the flutes  114  of the second layer of corrugations  110  include a much shorter wavelength of β′ and a much small amplitude of α′.  
     [0032] In order to form the shape of the cup  20  or pan  50 , a conventional thermoforming process can be used. In such a process, paperboard, which has already been corrugated to have the desired number of layers and corrugations of the desired shape and size, is subjected to a thermoforming mold. First and second dies (not shown) having a mating protrusion and cavity in the desired shape are provided, with the corrugated paperboard being positioned therebetween. The paper board is compressed between the dies under heat and pressure sufficient to deform the paperboard into a shape congruent with the dies. Upon retraction of the dies, the paperboard retains the desired shape, whereupon the edges thereof can be trimmed or otherwise finished for sale.  
     [0033] From the foregoing, one of ordinary skill in the art will readily appreciate that corrugated paperboard dishware, serveware,.and cookware can be constructed based on the teachings of the present disclosure. Moreover, one of ordinary skill in the art will understand that variations on the disclosed embodiments can be produced without departing from the scope and protection afforded by the disclosure.