Patent Application
20190135520
The present disclosure relates to snack packages, and in particular to a technique for sealing rigid packages, for example those used for food products.
Various container and package designs have been used in the past to contain and display snack food products. Among the many existing snack containers and packages, some have contained multiple compartments for separately holding different types of snack products in a single package. For example, U.S. Pat. No. 5,657,874, Hustad et al., describes a rigid plastic base tray having at least three compartments covered with a flexible film that hermetically seals each of the compartments. U.S. Pat. No. 5,853,105, Roman et al., discloses a circular container comprised of two compartments hermetically sealed by a film placed over the top of the two compartments. U.S. Pat. No. 5,277,920, Weaver, Jr., discloses a food package consistent of two separate compartments covered by sealing means. However, each of these conventional snack packages provide multiple compartments for holding various snack products that are downwardly formed from an upper flat surface of the rigid container. Flexible film is used them laid across this upper flat surface to provide a seal for the snacks held in the downwardly formed compartments.
Unfortunately, this conventional design of multi-compartment snack packages suffers from several disadvantages. For example, the downwardly formed compartments only permit access to the various snack products held therein from the top of each compartment. This can often make it difficult for a consumer to reach down into a compartment to grasp the product, especially if the compartment(s) are relatively deep and the quantity of remaining snack product in such compartment(s) is low. Additionally, the products held in the various downwardly formed compartments are not readily visible to consumers. Thus, if such conventional multi-compartment packages are stacked on a display shelf, consumer may have to pick up a package and turn it in various directions to ascertain exactly what is held in each downwardly formed compartment. Furthermore, such conventional packages with downwardly formed compartments typically form the compartments of flexible or semi-flexible material, which permits easier crushing of the products within the compartments should external forces, including the mere grasping of the container by a consumer, be applied to the sides of one or more of the compartments.
Still further, the peelable films laid over the top surfaces of such conventional multi-compartment packages is not typically resealable over the package once it is open. Even in packages where the film can be laid back over the top surface of the package, the consumer's view of what product(s) remain in the various downwardly formed compartments is again obscured. Moreover, the mere use of flexible films over the top surfaces of such conventional multi-compartment snack packages is a weak material, which can be easily punctured during shipping of such packages or even the stacking of multiple similar packages on a display shelf.
Even in conventional packages having both rigid trays and rigid lids, when such rigid packages are configured to be reclosable for later and repeated use, such packages do not lend themselves for use with food products. More specifically, most packages for use with food products must be closed by the packager so that the food product is not exposed to external contaminants, such as dirt or even insects. As a result, food product packages are typically hermetically sealed. One conventional approach to seal such rigid, reclosable packages is to use an adhesive between to the rigid lid and rigid tray to provide the hermetic seal. However, the use of adhesives with food products is typically undesirable since higher temperatures can potentially cause flowing of the adhesive, which could contaminate the food product within or simply lose the integrity of the hermetic seal. Even excessive age can also reduce the effectiveness of such adhesives, again leading to potential loss in seal integrity. Moreover, adhesive residue tends to remain on the sealing surfaces of either or both the rigid lid or rigid tray, which leads to sticky mating surfaces between the two. Such remaining residue can also be a magnet for unwanted dust or other debris to collect on the mating surfaces.
Another conventional approach to creating a hermetic seal between the mating surfaces of a rigid lid and tray is to weld the mating surfaces. Such welding techniques may include both heat welding or ultrasonic welding techniques. However, while such welding of the rigid lid to a rigid tray can be effective in creating a hermetic seal for the package, welding the mating surfaces of the lid and tray does not result in a peelable seal that permits the repeated reclosing of the rigid lid over the rigid package. Specifically, such welding of the mating surfaces typically results in a permanent joining of the two surfaces, creating a destructive seal between the two. This is especially the case for ultrasonic welding where the mating pieces need to be made from the same or very similar material. Ultrasonically welding like materials essentially creates a single layer of that material, which is again a destructive seal between the two pieces. Consequently, attempting to peel apart these ultrasonically welded materials destroys the welded mating surfaces. For example, of one mating surface may remain on the other and vice versa, or tearing of the package may occur in other areas around the original mating surfaces. In either situation, the connecting portions of the rigid lid and rigid tray do not maintain a smooth, uniform surface that lends itself to reclosing of the lid onto the tray.
Therefore, there is a need for an improved rigid package for holding food products, and related technique for sealing such rigid food packages, that does not suffer from these and other deficiencies found in conventional packages. The disclosed principles provide such improved package and sealing technique.
To overcome the deficiencies of the prior art, the disclosed principles provide packages having a rigid lid, which thus offers far better protection for the enclosed products. Moreover, the rigid lid in the disclosed packages is reclosable on to the rigid tray, which allows the unique disclosed packages to be reusable if desired. Also, the rigid material comprising the disclosed trays prevents crushing of food products as often occurs in downwardly formed compartments found in conventional packages, which are formed of thinner, less rigid materials. For providing the hermitic sealing of a disclosed exemplary rigid package, the disclosed principles for a unique manner for sealing the rigid lid onto the rigid tray of such packages. This sealing technique allows the packaged to be hermetically sealed when provided by the original manufacturer/packager, but where the seal is breakable so as to remove the rigid lid from the rigid tray. More specifically, in order to provide hermitic sealing of the entire package, the seal is formed entirely around the perimeter of the package, and specifically may be provided where the flange of the lid's skirt meets the flange of the tray's skirt. While providing a seal between the meeting flanges of a lid and a tray is not on its own unique, it is how that seal is provided by the disclosed principles that is.
Accordingly, the disclosed principles provide for a welding technique for use in welding the flanges of a rigid lid sealed onto a rigid tray, such that the two may be easily separated but still repeatedly reclosable such that the rigid package may be reused. For this unique and advantageous ultrasonic welding technique, the disclosed principles provide for the inclusion of a unique delamination layer between the similar rigid materials used for forming the flanges of both the lid and the tray. To ultrasonically weld two rigid plastics sufficiently to provide a hermetic seal, both rigid materials should have the same or very similar material composition or chemistry in the welding interphase area in order for a satisfactory seal to be provided between the two. The disclosed principles provide for the delamination layer to be provide on one or both of the two rigid materials, but behind the seal interphase area so that the hermitic seal may still be created. This delamination layer operates such that it peels apart (i.e., delaminates) as the ultrasonically sealed rigid material of the lid flange and rigid material of the tray flange are pulled apart while opening the package initially. Moreover, this delamination layer may be coextruded with the sealant layer on one or both of the rigid materials.
In one aspect, hermetically sealed reclosable packages having rigid lids and rigid trays are provided. In one exemplary embodiment of such a hermetically sealed package, the disclosed package comprises a first flange comprised of a rigid plastic and having a first mating surface, and a first laminated layer disposed on the first mating surface of the first flange, wherein the first laminated layer comprises a delamination layer and a sealant layer positioned as the outermost layer of the first laminated layer. In addition, such an exemplary reclosable package comprises a second flange comprised of a rigid plastic and having a second mating surface configured to be ultrasonically welded to the first mating surface, and a second laminated layer disposed on the second mating surface of the second flange, wherein the second laminated layer comprises a sealant layer positioned as the outermost layer of the second laminated layer. In such embodiments, the first and second mating surfaces with the first and second laminated stacks interposed are ultrasonically welded to one another such that the first and second sealant layers are hermetically sealed. The hermetically sealed rigid package may then be opened by peeling the lid flange from the tray flange, which delaminates the delamination layer leaving substantially smooth surfaces between remaining lid and tray flanges, which in turn allow the rigid package to be easily reclosed repeatedly without interference from a destroyed interface between the original rigid flanges.
In other aspects, methods for providing a peelable hermetic seal on a rigid package are disclosed. In one embodiment, such an exemplary method may comprise providing a first flange comprised of a rigid plastic and having a first mating surface, and forming a first laminated layer on the first mating surface of the first flange, wherein the first laminated layer comprises a delamination layer and a sealant layer positioned as the outermost layer of the first laminated layer. Such an exemplary method may further comprise providing a second flange comprised of a rigid plastic and having a second mating surface configured to be ultrasonically welded to the first mating surface, and forming a second laminated layer on the second mating surface of the second flange, wherein the second laminated layer comprises a sealant layer positioned as the outermost layer of the second laminated layer. Also, such an method includes ultrasonically welding the first and second mating surfaces with the first and second laminated stacks interposed therebetween such that the first and second sealant layers are hermetically sealed to one another.
Numerous embodiments and advantages associated with each such embodiment are discussed in further detail below.
The detailed description that follows, by way of non-limiting examples of embodiments, makes reference to the noted drawings in which reference numerals represent the same parts throughout the several views of the drawings, and in which:
In view of the foregoing, through one or more various aspects, embodiments and/or specific features, the present disclosure is intended to bring out one or more of the advantages that will be evident from the description. The present disclosure makes reference to one or more specific embodiments by way of illustration and example. It is understood, therefore, that the terminology, examples, drawings and embodiments are illustrative and are not intended to limit the scope of the disclosure.
Also visible from this top view are a lid tab 105a and tray tab 110a, which in this embodiment may be grasped by a consumer and pulled in opposite directions, with the lid tab 105a being pulled upwardly and the tray tab 110a being pulled downwardly and away from the lid tab 105a, to separate the lid 105 from the tray 110. Texture features 105b and 110b may also be provided on the respective tabs 105a, 110a, to assist the consumer in maintaining their grasp of the tabs 105a, 110a when used to open the package 100 in this manner.
In this embodiment, the dividing walls 120 are shown as tapered or sloped from the center of the tray 110 towards the outer periphery of the tray 110. The slope of the walls 120 are such that the bottom periphery of the tray 110 includes a raised lip 110c that helps secure the product 115 held on the tray 110 from sliding off of the tray 110 when the lid 105 is removed. This tapered structure for the walls 120 permits partial viewing of the product 115 within the package 100 from the side by a consumer in those embodiments having a transparent or semi-transparent lid 105. Also, the sloped walls 120 allow easier grasping of the product 115 on the tray 110 by a consumer's fingertips once the lid 105 is removed from the tray 110.
Formation of the walls 120 and the tray 110 may be done in a single, unitary piece of rigid material by any viable plastic formation technology, or the walls 120 may simply be attached to the interior, bottom surface of the tray 110. In such latter embodiments, the walls 120 may all be formed in a single piece, and then that piece attached or otherwise affixed to the interior, bottom surface of the tray 110, or one or more of the walls 120 may be formed separately, and then the two or more pieces comprising the walls 120 attached or otherwise affixed to the interior, bottom surface of the tray 110. This embodiment of the package 100 may also include walls 120 that form any number of compartments on the tray 110 for holding product(s) 115. And it should be noted that while the four compartments created on the tray 110 of
Still further, the dimensions and slope of the walls 120 can be different from those in this illustrated embodiment. For example, in this embodiment of the package 100, the walls 120 not only have a thickness that tapers upwardly, where the base of each wall 120 is thicker than the top of each wall 120, but the walls 120 also have a taper as you move from the center of the tray 110 to the periphery of the tray 110. The upward tapering of the shape of the walls 120 is typical for those trays and walls manufactured using vacuum forming or injection molding, but may also be so tapered as an ornamental feature. Also, the overall thicknesses of the walls 120, whether at the top or bottom of a wall 120, or at the center-most or outer-most portion of a wall 120, can be selected as desired for each application. And similarly, the angle of the slope of each wall 120, when moving from the center of the tray 110 to the periphery of the tray 110 may also be different from the illustrated embodiment. Such sloping may also be included on less than all of the walls 120, if desired, and the slope on one or more of the walls 120 may be formed as a straight line, a curved line, or as in this illustrated embodiment, as a combination of partially curved and partially straight when moving from the center to the periphery of the tray 110. Still further, the slope of the tops of the wall(s) 120 may be reversed so that they slope from the periphery of the tray 110 downward to the center of the tray 110. Of course, a combination of upwardly and downwardly sloping walls may also be employed in a package constructed in accordance with the disclosed principles.
Also visible from the cross-sectional view of
Additionally, for this embodiment of the package 100, the ends of the skirts 125, 130 each further include a flange 125a, 130a laterally extending outward from the bottom ends of each skirt 125,130. The flanges 125a, 130a, in this embodiment, are formed coextensive with one another, and may be used create a seal for the package 100 that may be pealed apart by the consumer. The formation of such a seal using the flanges 125a, 130a is discussed in detail below, and such a seal can be provided at the factory packaging the products 115 for sale in the package 100, and thus permits the package 100 to hold any of the types of food products requiring hermetic sealing. Also, in this embodiment, the flanges 125a, 130a extend horizontally from their corresponding skirts 125, 130; however, the disclosed principles are not so limited. Thus, similar flanges 125a, 130a may be formed to extend in other directions as well. Moreover, although the flanges 125a, 130a are flat in this embodiment, a package in accordance with the disclosed principles may also include flanges 125a, 130a having a different shape, such as curved in either an upward or downward direction.
The unique structure and features of the package 100 illustrated in
Additionally, instead of the thin flexible film used in conventional packages, the disclosed principles provide packages having a rigid lid, which thus offers far better protection for the enclosed products. Moreover, the rigid lid in the disclosed packages is reclosable on to the rigid tray, which allows the unique disclosed packages to be reusable if desired. Also, the rigid material comprising the disclosed trays prevents crushing of food products as often occurs in downwardly formed compartments found in conventional packages, which are formed of thinner, less rigid materials. Still further, the upwardly formed walls of the disclosed packages may be formed as hollow walls, as shown in
For providing the hermetic sealing of a disclosed exemplary rigid package, the disclosed principles for a unique manner for sealing the rigid lid onto the rigid tray of such packages. This sealing technique allows the packaged to be hermetically sealed when provided by the original manufacturer/packager, but where the seal is breakable so as to remove the rigid lid from the rigid tray. More specifically, in order to provide hermitic sealing of the entire package, the seal is formed entirely around the perimeter of the package, and specifically may be provided where the flange of the lid's skirt meets the flange of the tray's skirt. While providing a seal between the meeting flanges of a lid and a tray is not on its own unique, it is how that seal is provided by the disclosed principles that is. As discussed above, conventional techniques for sealing the rigid lid and rigid tray of a package comprised of plastic is to either use an adhesive of some sort or to use a welding technique to join the two together.
In those cases where adhesive are not desirable for use on reclosable packages, as discussed above, ultrasonic welding techniques may be used. But as mentioned above, welding the flanges of the two components together is also not conducive for rigid packages that are intended to be reclosable in those cases when not all of the product within has been finished, or intended to be reusable such as when the package is desirable for reuse by consumers. Specifically, when like or similar materials are welded together, the areas of welding are not easily separated when opening the package. As such, the welded areas of the lid and/or tray, such as the illustrated flanges, tend to be destroyed as the two welded flanges are separated. This result would not leave flanges of the lid and tray with a smooth surface to be reclosed when the package is used for either saving unfished product or reusing the package for the storage of new product(s) or other item(s). Thus, the disclosed principles provide for a welding technique for use in welding the flanges of a rigid lid sealed onto a rigid tray, such that the two may be easily separated but still provide substantially smooth mating surfaces that permit the lid and tray to repeatedly reclosable such that the rigid package may be reused.
For this unique and advantageous ultrasonic welding technique, the disclosed principles provide for the inclusion of a unique delamination layer between the similar rigid materials used for forming the flanges of both the lid and the tray. Of course, instead of being located on flanges, the delamination structure disclosed herein may also be included in other advantageous areas of a rigid package. To ultrasonically weld two rigid plastics sufficiently to provide a hermetic seal, both rigid materials should have the same or very similar material composition or chemistry in the welding interphase area in order for a satisfactory seal to be provided between the two. The disclosed principles provide for the delamination layer to be provide on one or both of the two rigid materials, but behind the seal interphase area so that the hermitic seal may still be created. This delamination layer operates such that it peels apart (i.e., delaminates) as the ultrasonically sealed rigid material of the lid flange and rigid material of the tray flange are pulled apart while opening the package initially. Moreover, this delamination layer may be coextruded with the sealant layer on one or both of the rigid materials.
Looking at
In exemplary embodiments, the rigid material 410 for the flange may itself be a laminated material, or it may be formed from a single layer of material. Exemplary materials for the rigid layer 410 may include compounds such as amorphous polyethylene terephthalate (APET), crystalline polyethylene terephthalate (CPET), polyethylene terephthalate glycol (PETG), polypropylene (PP), and polystyrene (PS), or even combinations of one or more of these materials. Each of these materials are safe for use in packages used for food products, and yet also provide the rigid structure for packages manufactured in accordance with the disclosed principles. However, other advantageous materials may also be employed, and no limitation to any particular material is intended or should be implied. In addition, the rigid material 410 to be ultrasonically welded may be formed to a thickness of about 15 to 30 mils, depending on the application. In exemplary embodiments, the coextruded sealant layer 420 would typically be formed as a much thinner layer, such as about only 2 mils thick. Other thicknesses may also be provided for the laminate sealant layer and the rigid layer, and the proportion in thickness between the two is determined by the composition of the rigid material 410, as well as the parameters employed for the ultrasonic welding of the two rigid materials.
Looking now at
For the specific layers in this exemplary embodiment, immediately adjacent to the rigid material 410 is an adhesive layer 510, which in this embodiment is a polyethylene (PE) layer 510. The PE layer 510 operates as an adhesive joining the rigid material 410 and the delamination layer 520 located on its opposing surface. The delamination layer 520 serves as the peelable layer for the coextruded layers. As used herein a “peelable layer” is a layer of material that can be broken along a specified direction of travel, and which is typically easy to open in that the peelable layer requires less force to destroy than a destructive seal created by one or more joined layers. In one embodiment, the delamination layer 520 is comprised of an oriented polymer layer, such an ethylene propylene peel polymer (EP) layer. Such a polymer material may be formed with long polymeric molecules aligned in a given direction, causing the material to preferentially peel along that direction. Of course, one or more other materials having a similarly advantageous molecular structure, such as butylene, polybutylenes and ionomers, may also be used as the delamination layer 520.
Next in the coextruded stacked layer 420 is a barrier layer 530, which in exemplary embodiments may be comprised of a metalized polypropylene or ethylene-vinyl alcohol copolymer (EVOH), or one or more other barrier materials having similar properties. After the barrier layer 530, a sealant layer 540 is provided as the outermost layer of the stack. The sealant layer 540 may be comprised of ethylene vinyl acetate (EVA), but one or more other materials having similar properties may also be employed. For example, linear low-density polyethylene (LLDPE), ionomers and metallocenes, or blends thereof, may also be employed as the sealant layer 540. The sealant layer 540 provides one-half of the seal interphase (i.e., either for the rigid lid flange or the rigid tray flange) used between the two flanges so that a hermetic seal may be created by the ultrasonically welded flanges. In some embodiments, sandwiched between the barrier and sealant layers 530, 540 may be another adhesive layer, such as another PE layer or other adhesive. It should also be noted that additional layers may also be included for a coextruded stacked layer 420 adhered to a rigid packaging material as disclosed herein, so long as the delamination layer is included to provide the peelable characteristic that avoid destroying the ultrasonically welded rigid materials.
Looking now at
As shown, exemplary materials are illustrated for the various layers of the coextruded sealant layers disclosed herein. But as noted previously, other exemplary materials having the same or similar properties and characteristics may alternatively or additionally be used. Specifically, APET is used as the rigid material 620, while EP is again used as the peelable delamination layer 630. In addition, EVOH is illustrated as being used for the barrier layer 640 of the coextruded stack, while EVA is provided as the sealant layer 650. For the rigid tray flange 610b, the outermost layer is also and EVA sealant layer 660 so as to properly seal with the sealant payer 650 of the rigid lid flange 610a through ultrasonic welding. In addition, the lid flange's barrier layer 670 is also formed of EVOH, and another adhesive layer 680 is used as an adhesive layer for adhering the coextruded stacked layer to the APET layer 690 used for the rigid tray flange 610b.
In one exemplary embodiment, the above-noted materials were employed for their respective layers for rigid flanges to be ultrasonically welded using the techniques as disclosed herein. Also, in this embodiment the rigid lid flange 610a was formed with a total thickness of 27 mils. More specifically, the rigid lid and its flange were formed of clear APET material to a thickness of 25 mils, and the coextruded stack having the delamination layer 630 was formed to a total thickness of 2 mils. The rigid tray flange 610b was formed with a total thickness of 20 mils. Specifically, the rigid tray and its flange were formed of a black APET material to a thickness of 18 mils, and the coextruded stack of EVA 660, EVOH 670 and the adhesive layer 680 without a delamination layer was formed to a thickness of 2 mils.
These exemplary materials were ultrasonically welded to weld and seal the two rigid flanges 610a, 610b. The welded seal should provide a hermetic seal between the two rigid flanges, but be formed as a peelable seal instead of a destructive seal. It should be noted that one or more of the ultrasonic welding parameters can be varied to affect the resulting bond between the two flanges 610a, 610b. For example, in embodiments employing these exemplary materials at the stated exemplary thicknesses, the various ultrasonically welding parameters may be selected from the parameter set forth in Table 1.
In other exemplary embodiments, the ultrasonic welding parameters may be substantially altered based on varying the thicknesses of the rigid plastic material being welded with a delamination layer in accordance with the disclosed principles. For example, a thickness of 18-28 mils for the rigid lid and its flange 610a and again formed of clear APET material, while the coextruded stack having the delamination layer 630 is formed to a total thickness of 1.5-2.5 mils. The rigid tray flange 610b in this embodiment may be formed with a thickness of also 18-28 mils, and again formed of a black APET material, while the coextruded stack of EVA 660, EVOH 670 and the adhesive PE layer 680 without a delamination layer may be formed to a thickness of 1.5-2.5 mils as well. In embodiments employing the disclosed layers of materials in these exemplary range of thicknesses, alternative ultrasonic welding parameters may be selected from the parameter set forth in Table 2.
In yet other exemplary embodiments, alternative ultrasonic welding parameters may be selected from the parameter set forth in Table 3.
The various ultrasonic welding parameters may be substantially altered based on the desired impact of the “dark line” or “wet line” area that represents the welded seal area between the flanges. More specifically, the seal area of the rigid package being sealed using the disclosed principles may be visible to consumers. In such package embodiments, a very consistent visible wet line around the perimeter of the package, or simply the welded/sealed areas, is typically desirable because of consumer visibility. Thus, a longer weld time combined with lower amplitude (e.g., the parameters of Table 2) may be employed (assuming the same or similar package materials and dimensions) to create a more visibly desirable wet line representing the seal area. However, in package embodiments where the seal area is not visible to consumers, or perhaps simply that the aesthetics of the seal area is not important, then, for example, a much faster weld time combined with a much higher amplitude (e.g., the parameters of Table 1) may be employed (again assuming the same or similar package materials and dimensions) to create seals more rapidly, regardless of the aesthetics of the wet line representing the seal area. In sum, one or more of the welding parameters may be altered as the materials are altered, the dimensions of materials are altered, and/or as the desired aesthetics of the weld area are altered, without departing from the broad scope of the disclosed principles.
Additionally, the ultrasonic welding anvil designs for use within the parameters listed in Table 1, Table 2 and Table 3 may also be selected from various advantageous designs. Exemplary designs for use with the disclosed principles include anvils with fine multilane, sharp multilane, 3 line, neural design-4-5 mm wide. Also, the dimensions and shapes of the welding anvils may be selected based on the size of the area to be ultrasonically welded, and even the reachability of the area to be welded. Moreover, the strength of the resultant seal may be adjusted by varying one or more of the amount of heat applied to the seal, the pressure applied to the seal, the length of time the heat and pressure are applied to the seal, as well as the geometry of the seal.
Looking now at
Turning to
However, as discussed above, the ultrasonic welding of the same or very similar rigid plastics creates a destructive seal between these two layers. In this embodiment, the EVA layers 650, 660 are welded together and thus become a single layer 655. Thus, if one attempts to peel these layers apart, the result is a destruction of the now-formed single layer of material, which then prevents the two separated parts from maintain a consistent shape and mating surface so that the two parts could be easily reclosed together. Thus, in accordance with the disclosed principles, the peeling apart of the two flanges 610a, 610b does not actually occur where these two parts were ultrasonically welded together. Instead, the delamination layer 630 provides the precise location where the rigid lid flange 610a may be peeled away from the rigid tray flange 610b. Accordingly, the force required to peel apart the delamination layer 630 must be significantly less than the force required to destructively peel the now-single EVA or other welded sealant layer 655 back into two separate parts.
If the two rigid flanges 610a, 610b are made from two materials with sufficient difference from one another, but still capable of being ultrasonically welded to each other, to provide an easy peelable seal, the seal between the two rigid flanges would not be sufficient to provide a hermetic seal between the lid and tray. This is because of the need for welded materials to be the same or very similar in order to provide a hermetic seal when ultrasonically welded. Thus, the disclosed principles are particularly advantageous for use in rigid packages intended for use to hold food products due to the creation of a hermetic seal between the rigid lid and rigid tray. But the disclosed principles also provide the additional advantages of providing a peelable seal, rather than a destructive seal, between the rigid lid and rigid tray so that the rigid package is actually reclosable for later use. As illustrated in
Moreover, the oriented polymer composition of the delamination layer 630 results in a smooth, uniform delamination or peeling/splitting of this layer 630 into the two remaining components 630a, 630b. This uniform delamination allows the new mating surfaces of the lid and tray flanges 610c, 610d to have a smooth finish similar to the original mating surfaces of the flanges 610a, 610b illustrated in
Looking at
For other pairs of rigid plastics having other thicknesses, which in turn employ different ultrasonic welding parameters such as those set forth in Table 2, the peel force may be slightly increased or decreased depending on the varied thicknesses. As such, the overall average range of peel force for peeling two rigid plastics having a delamination layer as disclosed herein is typically about 1.5 lbf to 4.0 lbf.
Referring now to
This embodiment of the package 900 again includes a lid tab 905a and tray tab 910a, which may be grasped by a consumer and pulled in opposite directions so that the lid tab 905a is pulled upwardly and the tray tab 910a is pulled downwardly to separate the lid 905 from the tray 910. However, this embodiment of the tabs 905a, 910a are formed in a rectilinear shape, whereas a triangular shape was used in the prior package embodiments discussed above. Texture features 905b and 910b may again be provided on the respective tabs 905a, 910a as before, to assist the consumer in maintaining their grasp of the tabs 905a, 910a. In this embodiment, the rectangular shape of the tabs 905a, 910a permits an elongated shape for the texture features 905b, 910b, whereas in prior package embodiments, the features were formed in an angular shape corresponding to the triangular shape of the prior texture features.
In some embodiments of a package as disclosed herein, grasping tabs are not provided on the flanges. Instead, inset portions along the lid flanges may be formed so as not to laterally extend as far out as the tray flanges, while the other portions of the lid flanges are formed coextensive with the tray flanges. As such, portions of the tray flange are exposed when viewing from above the package with the lid secured onto the tray. Using this non-coextensive portion of the lid flange that reveals portions of the tray flange, a consumer is able to easily separate the tray flange from the inset portion of the lid flange by simply pressing down on the exposed portion of the tray flange. By slightly pressing down this exposed area of the tray flange, the consumer can then easily separate the lid flange from the tray flange peeling the flanges apart as described herein when the rigid flanges have been hermetically sealed, or with enough force to overcome the securing feature(s) if the package has simply been reclosed after initial opening. In either case, the consumer may then pull the lid off of the tray.
Turning to
In this embodiment, the dividing walls 920 again are tapered or sloped from the center of the tray 910 towards the outer periphery of the tray 910. The slope of the walls 920 are again such that the bottom periphery of the tray 910 includes a raised lip 910c that helps secure the product 915 held on the tray 910 from sliding off of the tray 910 when the lid 905 is removed. This tapered structure for the walls 920 again permits partial viewing of the product 915 within the package 900 from the side by a consumer in those embodiments having a transparent or semi-transparent lid 905. As also mentioned above, the sloped walls 920 allow easier grasping of the product 915 on the tray 910 by a consumer's fingertips once the lid 905 is removed from the tray 910.
Formation of the walls 920 and the tray 910 can again be done in a single, unitary piece of rigid material by any viable plastic formation technology, or the walls 920 may simply be attached to the interior, bottom surface of the tray 910. In such latter embodiments, the walls 920 may all be formed in a single piece, and then that piece attached or otherwise affixed to the interior, bottom surface of the tray 910, or one or more of the walls 920 may be formed separately, and then the two or more pieces comprising the walls 920 attached or otherwise affixed to the interior, bottom surface of the tray 910. As mentioned above, the walls 920 maybe be formed to provide any number of compartments on the tray 910 for holding product(s) 915, as well as that the compartments created on the tray 910 can be or substantially equal dimensions and sizes, or may be formed in any size and shape with respect to one another. Similarly, the dimensions and slope of the walls 920 can also as before be different from those in this illustrated embodiment, in the same manner as discussed above for the prior embodiments of package constructed in accordance with the disclosed principles.
Also once again included again in this embodiment of the package 900 are a lid skirt 925 and a tray skirt 930 to be used as a closing feature for the package 900, in the manner discussed above for the prior embodiment. However, in this embodiment of the package 900, the skirts 925, 930 are now shown as being formed in an outward and upward configuration and coextensive with one another in corresponding complimentary shapes. Despite having skirts 925, 930 that are formed upwardly, this embodiment of the package 900 again includes flanges 925a, 930a laterally extending outward from the ends of each skirt 925, 930, similar to the package 200 of
Also, a securing feature 935 may also be seen on the package 900; however, in this embodiment, the securing feature 935 is formed as corresponding convex (outward) curvatures on the upward, vertical portions of the skirts 925, 930. While this securing features 935 again assists in securing the lid 905 onto the tray 910, this embodiment of the securing feature 935 is provided as a single set of corresponding curved features that are formed around the entire skirts 925, 930 of the lid 905 and tray 910. Opening the securing feature 935, however, is similar to other embodiments in that the lid tab 905a and the tray tab 910a may be pulled apart by the consumer to overcome the securing feature 935 and thus separate the lid skirt 925 from the tray skirt 930 to open the package 900. Of course, other shapes for such a securing feature 935 that circumscribes the skirts 925, 930 of the package 900 may also be employed. To provide the snap-fitting of the lid 905 onto the tray 910, the securing feature 935 in this embodiment is formed all the way around the lid and tray skirts 925, 930 of the package 900. Although this embodiment of the package 900 includes only a single securing feature 935 formed around the perimeter of the skirts 925, 930, other rigid package embodiments may include two or more such features 935 or may include multiple securing features staggered around various points of the perimeter of the package, such as those discussed in the above package embodiments. Also, the securing features 935 may be comprise of a combination of the illustrated securing feature 935 along with one or more other features, such as the capsule shaped securing features of the prior discussed package embodiments.
In some embodiments of a rigid package as disclosed herein, grasping tabs are not provided on the flanges. Instead, inset portions along the lid flanges may be formed so as not to laterally extend as far out as the tray flanges, while the other portions of the lid flanges are formed coextensive with the tray flanges. As such, portions of the tray flange are exposed when viewing from above the package with the lid secured onto the tray. Using this non-coextensive portion of the lid flange that reveals portions of the tray flange, a consumer is able to easily separate the tray flange from the inset portion of the lid flange by simply pressing down on the exposed portion of the tray flange. By slightly pressing down this exposed area of the tray flange, the consumer can then easily separate the lid flange from the tray flange peeling the flanges apart as described herein when the rigid flanges have been hermetically sealed, or with enough force to overcome the securing feature(s) if the package has simply been reclosed after initial opening. In either case, the consumer may then pull the lid off of the tray.
In the numerous embodiments of the inventive subject matter disclosed herein, such embodiments may be referred to herein, individually and/or collectively, by the term “invention” merely for convenience and without intending to voluntarily limit the scope of this application to any single invention or inventive concept if more than one is in fact disclosed. Thus, although specific embodiments have been illustrated and described herein, it should be appreciated that any arrangement calculated to achieve the same purpose may be substituted for the specific embodiments shown. This disclosure is intended to cover any and all adaptations or variations of various embodiments. Combinations of the above embodiments, and other embodiments not specifically described herein, will be apparent to those of skill in the art upon reviewing the above description.
The Abstract is provided to comply with 37 C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.
The description has made reference to several exemplary embodiments. It is understood, however, that the words that have been used are for description and illustration, rather than words of limitation. Changes may be made within the purview of the appended claims, as presently stated and as amended, without departing from the scope and spirit of the disclosure in all its aspects. Although this description makes reference to particular means, materials and embodiments, the disclosure is not intended to be limited to the particulars disclosed; rather, the disclosure extends to all functionally equivalent technologies, structures, methods and uses such as are within the scope of the appended claims.
