Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D81/34—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D81/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D81/34—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package
  • B65D81/3446—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within the package specially adapted to be heated by microwaves
  • B65D81/3461—Flexible containers, e.g. bags, pouches, envelopes
  • B65D81/3469—Pop-corn bags
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2205/00—Venting means
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2581/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D2581/34—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
  • B65D2581/3401—Cooking or heating method specially adapted to the contents of the package
  • B65D2581/3402—Cooking or heating method specially adapted to the contents of the package characterised by the type of product to be heated or cooked
  • B65D2581/3421—Cooking pop-corn
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
  • B65D—CONTAINERS FOR STORAGE OR TRANSPORT OF ARTICLES OR MATERIALS, e.g. BAGS, BARRELS, BOTTLES, BOXES, CANS, CARTONS, CRATES, DRUMS, JARS, TANKS, HOPPERS, FORWARDING CONTAINERS; ACCESSORIES, CLOSURES, OR FITTINGS THEREFOR; PACKAGING ELEMENTS; PACKAGES
  • B65D2581/00—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents
  • B65D2581/34—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within
  • B65D2581/3437—Containers, packaging elements, or packages, for contents presenting particular transport or storage problems, or adapted to be used for non-packaging purposes after removal of contents for packaging foodstuffs or other articles intended to be cooked or heated within specially adapted to be heated by microwaves
  • B65D2581/3486—Dielectric characteristics of microwave reactive packaging
  • B65D2581/3494—Microwave susceptor

Definitions

• the present invention relates to an enhanced microwave popcorn package which achieves greater popping efficiency at less expense than predecessor packages.
• this invention relates to a highly efficient arrangement of kernels and associated oils and seasonings across a susceptor embedded in such a package. More particularly, this invention relates to the creation of a moisture and grease resistant barrier which isolates the greasy kernels and oils from the package and surrounding environment until the popping cycle is initiated.
• Popcorn has long been a favorite snack item, the popularity of which supports a large and profitable sector of the food industry.
• traditional cooking methods involving pans of hot, messy cooking oil that take relatively long to heat have steadily become less popular. Though these concerns have been somewhat addressed with healthier oils and hot air poppers, far and away the most dramatic innovation in this area was the creation of containers that enable popcorn to be prepared in a conventional microwave oven.
• Popcorn is commonly sold and stored in ready-to-use, shelf-stable, leak-proof packages which also serve as microwaveable cooking containers. These packages are designed to store a charge of popcorn kernels along with other edible ingredients such as shortening, cooking oils and seasonings/flavorings, (collectively the "slurry") in a collapsed configuration that reduces storage requirements and shipping costs.
• the material forming these packages is transparent to microwave energy so that the entire package can be placed in a microwave oven for the heating process. When microwave energy is applied to the product, the popcorn kernels rupture and assume the familiar shape of popped popcorn while the flexible package expands to accommodate the increased volume of the popped kernels.
• U.S. Patent No. 4,571,337 to Cage This is a traditional "grocery-bag" style with a flat bottom end and a crimp-sealed top end. Inwardly folded gussets provided on the sides permit the package to assume a relatively flat shape for shipping and storage.
• steam generated by the slurry and kernels is held in the bag causing the gussets to unfold and the bag to inflate.
• the corresponding pressure creates vent holes in the corners of the top seal.
• the top end of the inflated bag can be opened by pulling on diagonally opposite corners of the package.
• microwave ovens disperse microwave energy relatively evenly throughout the popcorn package. Moreover, while most microwave ovens generate enough energy to eventually pop the kernels, it is typically too low to pop them very fast. Since some variance in kernel structure is inevitable, some of the kernels will pop quite faster than others. Thus while the slower kernels absorb microwave energy toward popping, the faster kernels dry out and eventually scorch or burn.
• a susceptor is a very thin sheet of material, usually vacuum metalized polyester, that rapidly increases in temperature and radiates heat energy when subjected to microwave energy.
• a susceptor emulates the heated surface of a pan.
• the susceptor rapidly increases the temperature of the panel and adjacent kernels which in turn hastens the popping process. Since the cooking time is thereby shortened, the early popped kernels are subjected to less unnecessary energy. Moreover, since the susceptor concentrates most of the heat on the bottom surface, the lighter popped kernels can ascend to the higher, relatively cool areas in the package. Experimentation has also shown that packages employing susceptors cause kernels to pop with greater volume than packages without susceptors.
• the susceptor and kernels are placed near the middle of the package so that the popped kernels have sufficient space to escape the susceptor's heat.
• the manufacturing processes used to make these packages must position the kernels adjacent the susceptor rather than permitting gravity to pull them to either end of the package. This is currently accomplished through a vertical filling process in which the bottom portion of the package length is folded over the middle section and the kernels and slurry are poured in the open top. The top section of the package is then sealed and folded over the middle section to hold the kernels in place. This keeps the unpopped kernels from lodging in the ends, and reduces the required susceptor size. This process is illustrated and described in more detail in European Patent Application Number 88304722.7.
• the vertical filling process positions the kernels and slurry generally in the middle of the package adjacent the susceptor, it does not do so very well. Instead of distributing evenly across the susceptor, the kernels tend to collect along the fold between the bottom and middle sections. Generally, the kernels and slurry in such vertically filled packages cover approximately 25% of the available susceptor. This uneven build-up reduces popping efficiency because the kernels positioned immediately adjacent the susceptor heat much faster than the kernels that start farther from the susceptor. Thus the overall cooking time is lengthened, as is the lag time between the early and late pops.
• U.S. Patent No. 4,038,425 to Brandberg et al. teaches a popcorn package which is not filled vertically, but is in communication with a smaller exterior compartment that holds the popcorn and slurry prior to popping. The idea is that by holding the kernels in a small compartment until they pop, heat will be more easily contained and higher temperatures reached.
• This design keeps the kernels and slurry from the package folds, but at the costs of preventing the unpopped kernels from evenly dispersing across the susceptor and inhibiting the escape of the popped kernels to the cooler areas of the package.
• Another problem with the Brandberg package is that since the storage compartment communicates freely with the inside of the bag, it does not protect the popcorn slurry during shipping and storage and the kernels can spill in the package if the proper orientation is not maintained.
• the external compartment creates an irregular shape that is difficult (and expensive) to manufacture and bulky to transport and store.
• Grease-proof paper is typically made with very long, tightly interwoven fibers. The longer the fibers, and the tighter they are woven, the more grease resistant the paper will be.
• Grease resistance can also be attained by treating the paper with a fluorocarbon compound (e.g. 3M ® brand FC-807) during the papermaking process.
• a fluorocarbon compound e.g. 3M ® brand FC-807
• the degree of grease resistance is also a function of the amount of fluorocarbon compound that has been applied.
• High quality grease-proof paper can resist strike-through for six months or more, but this protection comes at a significant material and manufacturing cost. Printing on greaseproof paper can also be difficult since the paper is resistant to ink.
• dual-layered packages having grease-proof paper on the inner surfaces, and ink receptive paper on the outer surface are popular.
• the inner layer could be formed of bleached greaseproof Kraft paper of approximately 25 lbs./ream and the outer layer could be formed of plain bleached Kraft paper of approximately 30 lbs./ream.
• These layers, along with adhesive therebetween, typically provide sufficient grease resistance, but disadvantages include the relative heaviness which increases shipping costs, and stiffness which hinders the expansion of the package.
• Grease protectors that block the flow of grease along the more vulnerable folded or creased areas.
• Grease protectors are described as strips of heat seal adhesive affixed to the inner and/or outer surfaces of the package along folds or creases.
• Another problem associated with storing the slurry loose in the package is that the slurry must be relatively solid at room temperature to prevent it from flowing away from the desired position adjacent the susceptor.
• liquid slurries are shunned because the package would require very high grease-resistance to prevent strike-through, and the ends would have to be sealed particularly well to prevent leakage. Nonetheless, liquid slurries require less energy to heat and are generally understood to impart a better taste to the finished popcorn.
• Multi-purpose packages have also been introduced which provide means for converting the package into a convenient serving container after the kernels have been popped.
• One early such package is described in U.S. Patent No. 4,292,332 to McHam.
• One of the panels of the McHam package includes an "H” pattern of weaknesses that release excess vapor during popping. After the popping process is complete, the weaknesses assist the consumer in opening the package as the panel can be torn along the weaknesses to create two "flaps" (i.e. the upper and lower halves of the "H”). These flaps are then folded over to provide access to the interior of the container.
• a McHam style package risks early ruptures along the pattern of weaknesses as the expanding kernels exert pressure inside the package. If the weaknesses can withstand this pressure during popping, they will likely be too strong to permit easy tearing after the kernels are popped. Moreover, since there is no handle on the package with which to remove the panel, the consumer must initially push the flaps into the package before reaching in to pull an edge away.
• the McHam package also lacks means by which the panels and flaps can be pulled entirely off the package to create a large aperture through which the consumer can obtain the popcorn.
• This Hunt-Wesson package includes two parallel separation lines extending longitudinally down the length of the package. These separation lines are formed by reinforcing the adjacent areas with contact tape, whereby any tears initiated along the separation lines will tend not to deviate to other areas of the package. Thus after the kernels have been popped, the entire section of the panel between the separation lines can be removed. This leaves a relatively large aperture through which the consumer can access the popcorn without having his hand soiled by the greasy flaps.
• the intended tear lines can be weakened to provide added control. This product works well for its intended purpose, but the panel reinforcement, and/or weakening, to create the separation lines represent additional material and manufacturing costs that would preferably be avoided.
• the present invention pertains to a microwaveable popcorn product that addresses many of the above-described deficiencies in currently available packages. Moreover, these objectives are accomplished with a package design that is inexpensive to manufacture.
• the primary structural components of the inventive product include a package comprising multiple panels of flexible, microwave transmissive material joined together to form an inner cavity.
• a susceptor is mounted on one of the panels such that it is adjacent an inner surface of the package, and a charge of microwaveable popcorn kernels and slurry is placed on the inner surface of the cavity adjacent the susceptor.
• the susceptor is capable of converting microwave energy to heat, and the popcorn kernels are prone to pop and expand when heated.
• An important feature of this invention is that the slurry and popcorn kernels are dispersed in an even, uniform thickness relative the susceptor. Thus the heat generated by the susceptor will be evenly distributed to the kernels so that they will pop at a substantially equal rate.
• This aspect can be refined by dispersing the kernels in a single layer adjacent the susceptor such that all the kernels are as close to the susceptor as possible.
• This feature can be further refined by dispersing the charge of popcorn kernels and slurry across the entire susceptor.
• the heat generated by the susceptor will be efficiently transferred to the kernels and slurry with limited heat transfer to the surrounding package material that could cause charring.
• the charge is securely contained in an envelope located within the cavity of the package.
• the envelope is strong enough to contain the charge of unpopped kernels until the popping process begins. However, when subjected to the steam, high temperatures and expansion pressure created by the kernels during the popping process, the envelope will burst and release its contents. Thus the unpopped kernels will be protected and held in place through shipping and storage, but when the popping process is initiated the popped kernels will escape into the larger cavity of the package.
• the envelope is created from two sheets of material that are entirely independent of the package material, yet reside within the package. This embodiment is advantageous in that it permits the envelope to be manufactured separate from the package, and subsequently inserted into the package.
• an envelope is created with a cover that overlies the charge of kernels and is adhered to the inner surface of the package around the perimeter of the charge.
• the envelope is an integral part of the package which ensures that the charge will be located in the proper position and saves the cost of an additional sheet of envelope material.
• the envelope is created with only the panels that form the package. This is accomplished by compressing the inner surfaces of top and bottom package panels together against the charge, and releasably sealing the inner surfaces around the perimeter of the charge.
• the adhesive layer there are no additional materials required over that which are already part of the package.
• the package is divided into three sections: a top section, a bottom section and a middle section that resides between the top and bottom sections.
• the susceptor and charge of kernels and slurry are positioned in the middle section of the package; and, the top and bottom ends are folded over the middle section.
• the charge is retained in the middle section between the folds. This ensures that the evenly dispersed charge remains adjacent the susceptor, and in the best position for popping.
• side panels forming the package include multiple gussets and the charge is placed along the channel at the longitudinal center of the package between the innermost folds of the gussets.
• This arrangement enhances the freedom of the kernels to move about the package during the popping process and reduces the thickness of the package. This also serves to hold the kernels in the center portion of the package adjacent the susceptor.
• a susceptor is mounted directly onto one of the surfaces of the envelope adjacent the charge.
• the charge will remain immediately adjacent the susceptor no matter where the envelope is located in the package ensuring that susceptor's heat is efficiently transferred to the charge.
• This also permits the use of a smaller susceptor than if the susceptor was mounted on the package.
• the charge of popcorn kernels is displaced in an even, uniform thickness inside the envelope and adjacent the susceptor.
• heat generated by the susceptor when microwave energy is applied to the product will be evenly distributed to the kernels so that the kernels heat and pop at a substantially equal rate.
• the charge of popcorn kernels is dispersed in a single layer adjacent the susceptor.
• a panel of the package has a susceptor mounted thereon, and the envelope is placed adjacent the susceptor.
• the envelope can be used with currently available package styles.
• the envelope can be produced at less expense than if it included a susceptor.
• the envelope is secured to an inner surface of the cavity inside the package.
• the consumer can empty the popped kernels from the package without removing the empty envelope in the process.
• the envelope is substantially impervious to water.
• the moisture content of the charge and slurry will remain substantially constant from the time that the charge and slurry are sealed in the envelope until the envelope bursts.
• This aspect can be refined by lining the envelope with polyester to attain the moisture barrier.
• This aspect can be further refined by evacuating the envelope of air as this further maintains a predetermined level of moisture in the envelope.
• the envelope comprises two layers of material that are placed on either side of the charge of kernels and adhered to each other around the perimeter of the charge.
• the adhesive used to join the layers has a bonding strength that is strong enough to hold the layers together during shipping and storage, but too weak to contain the expansion pressure created within the envelope when the kernels are popped. Thus when the popping process is begun, the layers of the envelope will separate thereby releasing the kernels into the package cavity.
• the adhesive used to bond the layers of the envelope is heat sensitive such that the bonding strength diminishes as the temperature increases.
• the adhesive will be strongest when it is required to hold the envelope together (i.e. during the relative cool periods of shipping and storage); but will be weakened by the very process that requires its release.
• a susceptor is mounted to one of the layers of the envelope adjacent the charge and the adhesive.
• the package includes gusseted side panels that permit the front and back panels to converge onto the envelope prior to popping, and diverge during popping.
• Front and back layers forming the envelope are securely attached to the front and back panels such that as the front and panels diverge, the layers of the envelope will be pulled apart. This serves two functions: it opens the envelope to release the unpopped kernels, and it keeps the envelope layers from mixing with the popped kernels.
• the edges of the front panel are joined to the edges of the side panels along two lap seams, and the lap seams are bonded together with a releasable adhesive. The releasable adhesive is strong enough to hold the package together during shipping, storage and the popping process.
• the adhesive is weak enough that it will permit the front panel to be peeled from the remainder of the package without tearing the package material. This creates a large aperture in the package to provide access to the interior cavity.
• a similar arrangement can be created in which the back panel, as opposed to the front panel, is removably attached to the side panels.
• Figure 1 is a plane top view of the exterior of the package of the invention.
• Figure 2 is a cross-sectional side view of the package, taken along the line 2-2 of Figure 1, illustrating a first embodiment of the invention in which the charge of kernels is arranged in a uniform thickness.
• Figure 3 is a plane side view of the package of Figure 1 taken after the end sections have been folded over the middle section.
• Figure 4 is a cross-sectional side view of an envelope utilized in a second embodiment of the invention to contain and protect the kernels and slurry.
• Figure 5 is a cross-sectional side view, similar to that illustrated in Figure 2, of the package incorporating the envelope illustrated in Figure 4.
• Figure 6 is a cross-sectional side view, similar to that of Figure 5, in which the popping process is partially complete and the package is partially inflated.
• Figure 7 is a perspective view of the package of Figures 5 and 6 after the package has been expanded by the popped popcorn kernels.
• Figure 8 is a perspective view, similar to that of Figure 7, of the package after a panel has been partially removed along with a portion of the envelope.
• Figure 9 is a cross-sectional side view, similar to that illustrated in Figure 2, of another embodiment of the package in which a cover is draped over the kernels and attached to the inner surface of the package to envelope the kernels.
• Figure 10 is a cross-sectional side view of similar to that of Figure 9 in which the popping process is partially complete and the package is partially inflated.
• Figure 11 is a cross-sectional side view, similar to that illustrated in Figure 2, of another embodiment of the package in which the front and back panels of the package are sealed around the charge to envelope the charge.
• Figure 12 is a cross-sectional side view, similar to that of Figure 11, in which the popping process is partially complete and the package has partially inflated.
• Figure 13 is a top elevational view of the embodiment of Figures 11 and 12. A comer of the back panel has been partially removed from the remainder of the package for illustrative purposes.
• Figure 14 is a perspective view of the package of Figures 11, 12 and 13 after the package has been expanded by the popped popcorn kernels.
• Figure 15 is a perspective view, similar to that of Figure 14, of the package after a panel has been partially removed to allow access to the popped kernels within.
• Figure 16 is an illustration of the preferred manufacturing process for creating the package of this invention.
• the present invention relates to a microwave popcorn product, generally indicated as 1 in the accompanying drawings.
• the package contains a charge of popcorn kernels 2 that expand into puffed edible popcorn 3 when heated in a microwave oven.
• the primary structural components of the package include a rectangular front panel 4, a rectangular back panel 5, and two rectangular side panels 6 and 7 which connect the sides of the front and back panels to form inner cavity 8.
• the front panel 4 is the panel that is to be placed downward when the package is placed in a microwave oven.
• Various sheet materials may be used to form the panels, so long as the basic requirements of the package are met.
• the package must be stiff enough to resist tearing under the expected loads, but at the same time it must be flexible enough that the internal steam and popcorn volume can expand the package from its compressed configuration. If the kernels are loosely stored in the package, the panels should resist leaking or staining for the expected periods of shipping and storage as well as during the popcorn process.
• a two-ply construction with an inner grease-proof paper layer of 20-25 lbs./ream adhered to an outer machine finished paper layer of 25-30 lbs/ream is suitable.
• a suitable material for a single ply package is a grease-proof paper approximately 0.5 to 1.0 mils thick with a weight of about 35-60 lbs./ream Machine glazed papers are also suitable, but can be too rigid if too thick.
• the surface of the paper can also be treated with a commercially available fluorocarbon stain inhibitor such as 3M* Inc. brand FC-807.
• a commercially available fluorocarbon stain inhibitor such as 3M* Inc. brand FC-807.
• All four panels of the package 1 comprise a top end 9 and a bottom end 10. Both ends of front panel 4 and back panel 5 must be connected to close the package and fully contain the popcorn 2.
• the preferred design is the "tube” method in which the top and bottom ends 9,10 are secured directly to each other.
• a bottom panel (not illustrated) can be included to create the "grocery-bag” style described in the background section supra. The ends are closed by crimping the material or applying a heat sensitive adhesive to the inner surfaces and placing the ends in a heated press. Typical adhesives used to close the ends include polyvinyl acetate or polyethylene vinyl acetate.
• a susceptor 11 is preferably adhered to the front panel 4 to enhance popping performance.
• a susceptor consists of a thin layer of metal adhered or evaporated on to a stmctural base such as a sheet of polyester. When subjected to microwave energy the susceptor rapidly increases in temperature and radiates heat energy to its surroundings.
• the contents of the package 1 principally include a charge of unpopped kernels 2 mixed with a slurry of shortenings, cooking oils and seasonings (not illustrated) to enhance the flavor and texture of the resulting popcorn 3.
• Room temperature stable ingredients are preferable so that refrigeration is not required, and if the slurry is to be loose in the package it should be solid at room temperature. If a leak-proof envelope, discussed infra, is used, the slurry can be a liquid.
• the charge of kernels and slurry 2 is dispersed across the susceptor 11 in a uniform thickness "x,” and covers substantially the entire surface area of the susceptor.
• Popping performance can be further improved by using a susceptor 11 that is large enough to disperse all of the kernels 2 in a single layer.
• all of the kernels would preferably be laid side-by-side on the front panel 4 immediately adjacent the susceptor.
• Each kernel would thus receive the maximum amount of energy available from the susceptor from the beginning of the microwave cycle.
• at least until the kernels start to pop each would receive an equal amount of energy, thus forwarding the goal of popping all the kernels at the same time.
• the size of the susceptor, and front and back panels might have to be modified to accommodate this arrangement.
• the side panels 6, 7 each include multiple gussets 12 which allow the package 1 to maintain a collapsed configuration prior to the preparation of the popcorn kernels 2.
• These multiple gussets are formed in each side panel by creating inwardly directed folds parallel to the longitudinal axis of the package thereby giving the side panel a pleated or accordion-like configuration.
• the stiffness of the side panel material causes the gussets to remain compressed so that the package will remain relatively flat during storage and shipping.
• the side panel material must be flexible enough that the gussets will expand when subjected to the internal pressure created during the popping process. Thus the package will inflate to accommodate increased interior volume of the popped popcorn 3.
• gussets 12 do not protrude significantly into the inner cavity 8, they do not hinder the free flowing movement of kernels 3 during popping. This freedom can be further improved by placing the entire charge and slurry between the inner folds of the gussets whereby the kernels will not get stuck under the gussets (See Figure 2). Moreover, since the inner gussett edges form a barrier of sorts, the kernels will be held in the center portion of the package adjacent the susceptor. Another advantage of placing the slurry between the gussets is that the overall thickness of the package will be kept to a minimum. Depending on the number and size of the kernels used, this feature might also require modification of the package dimensions and/or susceptor size, but one skilled in the art could readily make these modifications.
• the susceptor 11 need not cover the entire front panel 4 to pop the kernels 2 efficiently, but if the susceptor covers only a portion of the panel, the kernels must be held adjacent that portion. As explained above, the gusset edges can be used to keep the kernels from spilling off the sides of the susceptor. It is also advisable to keep the unpopped kernels from the ends 9,
• the package 1 is longitudinally divided into three approximately equal sections: a top section 13, a middle section 14 and a bottom section 15; and, the susceptor and charge are placed on the middle section.
• the package is folded between the sections such that the top and bottom sections overlie the middle section (as illustrated in Figure 3). The combination of the gusset edges and these folds hold the kernels in place until the steam and expansion pressure of the popping process cause package to unfold.
• FIGS 4-8 illustrate a microwaveable popcorn package 1 similar to Embodiment 1, with the exception that the charge 2 is not loose in the package. Rather the charge is securely contained in an envelope 16 which in turn is located in the cavity 8 of the package.
• the envelope must be made of a material that is transparent to microwave energy, preferably polyester, whereby microwave energy will heat the popcorn kernels and slurry within. Since the envelope is too small to contain the kernels after they have popped, the structural constitution of the envelope is designed to burst when subjected to the heat, steam and expansion pressure created by the kernels during the popping process. After the envelope has ruptured, the kernels will escape into the surrounding package which holds the popped kernels 3 until they are removed by a consumer.
• a susceptor 11 is preferably included in Embodiment 2 to aid the popping process. The susceptor is preferably mounted to the lower surface of the envelope (as is illustrated in
• the charge 2 is preferably dispersed in a uniform thickness inside the envelope.
• the kernels will be heated at a substantially even rate and there will be little to no dry area on the susceptor.
• the heating efficiency will be further improved.
• a front layer 17 has the charge 2 positioned on the upper surface thereof, and a back layer 18 is draped over the charge.
• the edges 19 of the front and back layers are adhered together around the charge with a releasable adhesive 20.
• a releasable adhesive is used so that the envelope will split open when it is subjected to the internal expansion pressure created during the popping process.
• the bonding strength of the adhesive decreases when subjected to steam and increased temperatures.
• the adhesive will be strongest during the relatively cool periods of shipping and storage, and weakest when it is intended to release. The releasing effect is further improved if the susceptor
• the preferred adhesive for creating the envelope is DuPont Brand Selar PT 8307.
• the consumer will need to gain access to them. This is traditionally accomplished by opening an end of the package 1 and pouring the contents into a bowl (See e.g. the Burdette patent discussed supra) . Since it would be undesirable for the spent envelope pieces to be mixed with the kernels 3, the envelope 16 is securely mounted to the inner surfaces of the package cavity 8 such that it will remain attached after the popping process. This can be accomplished with a heat resistant adhesive such as a modified acrylic emulsion sold by Basic Adhesives, Inc. product no. BR-3885. Note that the adhesive used to secure the envelope to the package should be considerably stronger than the releasable adhesive used to seal the edges of the envelope. As illustrated in Figure 5, strips of heat resistant adhesive 21 secure the front layer 7 of the envelope to the inner surface of the front panel 4; and, strips of heat resistant adhesive 22 secure the back layer 18 of the envelope to the inner surface of the back panel 5.
• a heat resistant adhesive such as a modified acrylic emulsion sold by Basic Adhesives, Inc. product no. BR-3885
• Embodiment 2 also includes an improved method for allowing the consumer to access the popped kernels 3.
• a pair of lap seams 23 extend the longitudinal length of the package 1 and secure back panel 5 to side panels 6, 7.
• FIG. 7 illustrates a package of this embodiment after the popping process has been completed.
• Figure 8 illustrates the same package with the back panel partially removed. Note that if the back layer 18 of the envelope 16 is attached to the back panel 5, it too can be removed from the remainder of the package. Alternatively, if the front panel 4 was releasably attached to the side panels 6,7, the package could be turned over and the front panel and front envelope layer could be removed.
• the adhesive used along the lap seams 23 will not be subjected to as much heat, steam and internal pressure as the adhesive used to hold the envelope layers 17,18 together.
• the same releasable adhesive used for the envelope can be used for the lap seams 23.
• the width of the lap seams can be modified until the appropriate strength is reached. Applicant has found that Franklin Duracet 12 or Basic Adhesives, Inc. product no. BR-3885 works well for this application.
• the kernels 2 are preferably located in the middle section 14 of the package 1 to aid the flow of popped kernels about the package.
• the best way to accomplish this is to place the envelope in the middle section, and fold the top and bottom sections over the middle section to hold it in place during shipping and storage.
• the envelope can be made small enough to fit between the gussets, as illustrated in Figure 5, the freedom of the kernels during the popping process will be improved.
• polyester for envelope 16 has also been shown to be very effective in preserving the freshness and popping performance of the kernels 2.
• the mechanics of popping popcorn rely on moisture within the kernels to expand and rupture the exterior shell of the kernel. Preferably sufficient moisture is present to reach a very high pressure and cause a violent rupture as this creates larger, puffier kernels. If the kernels are too dry due to losee of moisture during storage, insufficient internal vapor pressure will be generated leading to smaller popped kemals and increased number of kernels that do not pop at all. However, if the moisture content is too high, the pericarp will become pliable and rubbery and will split open with little intensity. Thus it is important to maintain the moisture content within set parameters.
• the invention addresses this goal by creating the envelope 16 out of polyester, which is substantially impervious to the transmission of water. This is advantageous over the prior art polypropylene packets that covered the entire package.
• the envelope 16 is much smaller and lighter, and does not include the package material or large volume of air which can absorb moisture from the kernels and slurry. The moisture content and slurry freshness can be further controlled by drawing a vacuum in the envelope.
• an envelope 16 is beneficial in that lighter, inexpensive materials can be used for the package panels 4, 5, 6, 7. Since the envelope contains the oily charge 2 for the vast majority of the product's life, the need for expensive grease-proof panel material is drastically reduced. Strike-through protection has traditionally focused on the affected elements of the package (i.e. the panels). Rather than trying to protect the panels from the oils, Applicant contained the source of the oils. Thus the only time that the oils and shortening come in contact with the panels is during and after the popping process. By this time, the product's remaining usefulness is typically less than V2 hour (or much less if the consumer pours the contents into a separate bowl).
• the envelope 16 also provides additional flexibility for the shortenings and oils used in the slurry. It was previously impractical to use liquid oils because they tended to soak through the panels and leak through any faults in the package. Solid shortenings and oils were also used because they helped to hold the charge in the intended position. Applicant's polyester envelope eliminates this reliance on solid shortening and oils. Since the envelope is constructed of polyester, it can hold the charge and associated ingredients regardless of the whether it is in liquid or solid form. Thus it is possible to use liquid shortenings and oils which is advantageous as the liquid oils are believed to impart better taste to the popcorn.
• FIGs 9 and 10 illustrate another embodiment of the invention.
• This package is similar to Embodiment 2 with the exception that front layer 17 of the envelope 16 is an integral part of the front panel 4 of the package 1.
• a layer of polyester 24 attached to the inner surface of the front panel 4 is a layer of polyester 24 on which a susceptor 11 has been evaporated.
• a strong, heat-resistant adhesive (not illustrated) holds the front panel, susceptor and polyester a single stratified unit.
• the back layer 18 of the envelope referred to more appropriately in this embodiment as the "cover,” is draped over the charge 2 and is releasably bonded to the inner surface of the front panel to create a polyester-lined envelope.
• a releasable adhesive is used to bond the cover to the front panel as was described above for Embodiment 2.
• the mechanics of Embodiment 3 will behave much as was described for Embodiment 2.
• the susceptor 11 When subjected to microwave energy, the susceptor 11 will heat the kernels 2 and the releasable adhesive 20. Through a combination of the increased temperature of the susceptor, and the steam and expansion pressure of the kernels, the releasable adhesive will permit to cover 18 to rise from the inner surface of the front panel 4 thereby spilling the kernels into the cavity 8.
• the back panel 5 will diverge from the front panel 4 to allow the popped kernels to fill the inner cavity of the package.
• the package 1 of Embodiment 3 also preferably includes a removable panel for permitting access to the popped kernels 3. If the back panel 5 is to be removable, the popped product will operate as described above (and illustrated in Figure 8). However, for Embodiment 3 is preferable to make the front panel 4 removable.
• the package can be rotated so that the front panel is on top and the package can be opened by peeling the front panel from the side panels along lap seams 23. This in turn removes the susceptor 11 and the lower layer of the envelope 16 from the remainder of the package.
• Embodiment 4 completes the progression of the configurations described above.
• the front and back panels 4, 5 also serve as the front and back layers of the envelope 16.
• a polyester sheet with a susceptor evaporated thereon is attached to the inner surface of the front panel, and a strong, heat-resistant adhesive holds these layers in a single stratified unit.
• the back panel 5 is constructed of a moldable material such as polyester.
• the inner surfaces of the front and back panels are converged together such that they envelope the charge of kernels 2 and are in contact around the perimeter of the charge of kernels.
• Inner strips of releasable adhesive 25 surround the charge and hold the inner surfaces of the front and back panels together around the perimeter (as can seen in Figure 11).
• the envelope is created simply by bonding the inner surfaces of the package together around the charge.
• the charge will have to be positioned between the gussets so that the inner surface of the front and back panels can meet all the way around the charge.
• the apparatus Embodiment 3 will perform in the manner illustrated in Figure 12.
• the releasable adhesive strips that hold the front and back panels together to form the envelope will release, the kernels will spill into the cavity 8, and the gussets will expand to allow the package to inflate.
• Embodiment 4 also preferably utilizes a removable panel.
• the back panel 5 is the preferred choice since it will likely be of a different material than the remainder of the package 1, and will need to be attached to the side panels 6,7 anyway. To the extent that a clear material such as polyester is used for the back panel, this package will be visually interesting in that it will be possible to watch the kernels 2 pop, and the popped kernels 3 will be visible through the panel after the popping process is complete.
• the back panel is attached to the side panels along lap seams 23 with a releasable adhesive 26. Note that the back panel in Figure 13 does not extend all the way to the package.
• FIGs 14 and 15 illustrate the package of Embodiment 4 after the kernels have been popped, and the back panel has been partially removed to expose the popped kernels 3.
• any one of the above embodiments could be "preferable.”
• Embodiment 4 is ideally the best arrangement in that it does not require additional panels or layers to create the envelope.
• Preferred Manufacturing Process Figure 16 illustrates the basic elements of a preferred manufacturing method for creating the apparatus of Embodiment 4.
• the package 1 is constructed with the back panel 5 below the front panel 4.
• Roll 30 deposits a continuous layer of polyester film onto conveyor belt 31.
• a vacuum is drawn below the surface of the conveyor such that the polyester film conforms to recesses 32.
• a charge of popcorn and slurry 2 is then deposited in the recesses from popcorn hopper 33.
• a solid slurry is used, it is preferably formed into solid cakes of popcorn and slurry sized to fill the recess.
• this horizontal manufacturing technique is also well suited to the use of liquid slurry since the recesses will contain the liquid until it is sealed in the envelope 16.
• the ingredients will be depositied onto a horizontal surface, gravity will spread them evenly across the recess, and ultimately the susceptor, which contributes to efficient popping action.
• the front panel 4 and side panels 6,7 are preferably constructed of a single layer of grease resistant paper, though non-grease-resistant paper could be used to reduce material costs.
• a continuous sheet of paper from roll stock 34 is used to create both the front and side panels of the package 1.
• two separate patterns of releasable adhesive strips are required to attach the polyester film (i.e. the back panel 5) to the gusseted side panels in Embodiment 4.
• Inner pattern 25 holds the inner surface of the paper stock to the inner surface of the polyester to create the envelope 16; and, outer pattern 26 holds the polyester to both the ends of the package and the edges of the gussets 12. Both of these releasable adhesive patterns are applied to the paper stock at station 39.
• the paper is rolled onto the conveyor and attached to the polyester layer at position 40. Care must be taken to synchronize the paper stock with the polyester film such that the susceptor 11 and adhesive patterns 25,26 are properly registered.
• Each susceptor 11 must be positioned directly above the recesses 32 and popcorn charge 2, each inner adhesive pattern 25 must register with the circumference of a recess, and the outer adhesive pattern 26 must correspond with the outer edges of the polyester film.
• the adhesives (releasable and hi -temperature) are secured in heat press 41. Individual packages are then cut off at station 42.
• the above described manufacturing process has been provided for illustration purposes only. In practice, these steps will not necessarily be performed in this order, and they might not all be performed in the same process.
• the gussets and susceptor could be added to the paper stock in a separate process, and the releasable adhesive could be applied to the polyester as opposed to the paper.
• this process can be adapted to create the package/envelope combinations of Embodiments 2 and 3. For example, if the steps of applying high temperature adhesive and gussets were removed, this process could be used to create the separate envelope that is to be inseted into a package (i.e., Embodiment 2.

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• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Food Science & Technology (AREA)
• Mechanical Engineering (AREA)
• Grain Derivatives (AREA)
• Package Specialized In Special Use (AREA)
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• 1999
  • 1999-04-09 JP JP2000610744A patent/JP2003515312A/ja not_active Withdrawn
  • 1999-04-09 AU AU36387/99A patent/AU3638799A/en not_active Abandoned
  • 1999-04-09 KR KR1020017012885A patent/KR20020024816A/ko not_active Application Discontinuation
  • 1999-04-09 CN CNB998167142A patent/CN1177734C/zh not_active Expired - Fee Related
  • 1999-04-09 CA CA002369555A patent/CA2369555A1/en not_active Abandoned
  • 1999-04-09 EP EP99918479A patent/EP1257483A2/en not_active Withdrawn
  • 1999-04-09 WO PCT/US1999/007801 patent/WO2000061456A2/en not_active Application Discontinuation
  • 1999-04-09 BR BR9917255-0A patent/BR9917255A/pt not_active Application Discontinuation

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