Abstract:
The disclosure relates to tubular, non-round composite paperboard container bodies having at least one wall portion defined by radially inverse curvature, and at least a second wall portion that is outwardly curved. In one preferred embodiment, the container body includes at least two body wall portions of inverse curvature, which are positioned in an opposed relationship. The two opposed body wall portions having inverse curvature provide an integral handle allowing easy grasping of the container body by the hand of a consumer, i.e. by the opposed thumb and fingers of a consumer.

Description:
The application is a continuation of Ser. No. 29/104,209 filed Apr. 30, 1999 now U.S. Pat. No. Des. 428,810. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to tubular, composite paperboard container bodies and to composite containers formed therefrom. More particularly, the present invention relates to tubular, composite paperboard container bodies with inverse curvature and to containers made from such bodies. 
     BACKGROUND OF THE INVENTION 
     Composite, tubular container bodies formed of paperboard in combination with other materials are widely used to package consumer food products and other products. Such container bodies generally have a curved, continuous wall formed by wrapping a plurality of plies onto a forming mandrel. For example, round composite containers are used to package food products such as orange juice, snack products, dough products, and the like, and also for packaging of other consumer and industrial products. 
     Alternative paperboard containers formed by folding and gluing flat paperboard blanks into various box-shaped configurations are also widely used to package various products including consumer food products. In order to maintain product freshness, particularly in the case of food products, paperboard box containers typically include a separate interior package formed of a flexible product wrap such as wax paper, plastic material, or the like, which is sealed and contains the food product. This interior package is inserted into the paperboard box container and maintains the food product in a fresh state until the interior package is opened by the end user. 
     In contrast, composite paperboard tubular containers typically include a lining layer or coating formed of a plastic or metal, e.g. foil, or the like which substantially reduces permeability of the paperboard material. No separate interior package is required in connection with such composite containers to maintain product freshness. In addition, because the composite paperboard tubular container bodies have a continuously curved wall formed of two or more layers, the body wall has improved strength as compared to the folded box type container. 
     Composite paperboard tubular container bodies are formed, as will be well known to the skilled artisan, on a mandrel by spiral winding processes, linear draw processes and convolute wrap processes. In such processes, a plurality of single or multi-layer plies are wrapped around the mandrel in a radially layered arrangement and are joined to each other by adhesive applied between the individual plies. Although such composite paperboard containers have found widespread use in commerce, the curved body walls which are generally responsible for various beneficial aspects of the container, including, for example, strength, integrity and the like, have also limited the choice of design and shapes for the container structure and thus have also limited the practical end uses available for the container. 
     SUMMARY OF THE INVENTION 
     The present invention provides tubular, non-round composite paperboard container bodies having at least one wall portion defined by radially inverse, i.e., inward curvature, and at least a second wall portion that is outwardly curved. The inverse curvature body wall portion substantially increases the range of designs and container configurations available to the skilled artisan for achieving numerous functional and design container body attributes, while also retaining the various beneficial attributes of composite container bodies formed by wrapping a plurality of plies around a mandrel. 
     In one preferred embodiment of the invention, the container body includes at least two body wall portions of inverse curvature, which are positioned in an opposed relationship. The two opposed body wall portions having inverse curvature provide an integral handle allowing easy grasping of the container body by the hand of a consumer, i.e., by the opposed thumb and fingers of a consumer. In one preferred aspect, this container body has a generally oblong cross-section and the opposed wall portions of inverse curvature are positioned on the elongated oblong wall portions at a location closer to one end of the oblong cross-section than to the other oblong end. This configuration provides a particularly desirable, integral handle-type configuration. The container body can be used for packaging of various consumer products and provides a particularly advantageous package for a pourable solid food product such as a crispy, breakfast cereal product. The integral handle allows the package to be easily manipulated by the end user for pouring product out of an open end of the package. At the same time, the curvature of the integral handles and of the other body wall portions of the container body, enhance the radial crush strength of the container body so that grasping of the container body is less likely to fracture or crush the fragile cereal product as it is poured out of the container body. 
     According to another preferred aspect of the invention, a container comprising the container body according to the invention includes an outwardly-curled beaded top edge portion adapted to receive a membrane closure and a snap-on overcap. Preferably, the container also includes a composite bottom closure. The membrane closure is preferably a peelable closure that can be removed by the end user upon fist use of the contents of the container while the snap-on overcap allows protection of the contents of the container between uses. The membrane closure and/or snap-on overcap can be adapted for closure of all or only a portion of the container top end. 
     The wall portions of inverse curvature in container bodies of the invention can accomplish other desirable functional aspects in packaging such as providing a divider for separating and stabilizing adjacent rows or stacks of individual product elements, i.e., stacks of crackers, potato chips or the like. The inverse curvature wall portions can also provide unique package configurations allowing packaging differentiation of products in the marketplace. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings which form a portion of the original disclosure of the invention; 
     FIG. 1 is a perspective view of one preferred container according to the present invention; 
     FIG. 2 is a front plan view of the container of FIG. 1 with portions thereof shown in cutaway to illustrate the membrane closure member and the outwardly curled beaded top edge of the container body of FIG. 1; 
     FIG. 3 is a top plan view taken along line  3 — 3  of FIG.  1  and illustrates the cross-section of the container body; 
     FIG. 4 is a greatly enlarged, exploded, front plan cross-sectional view of a front portion of the top and bottom of the container of FIG.  1  and illustrates the composite bottom closure, the outwardly curled beaded top edge of the container body; the membrane closure member, and the snap-on overcap; 
     FIG. 5 is a greatly enlarged view of a portion of the body wall cross-section illustrated in FIG. 3; 
     FIG. 6 is a schematic diagram illustrating a preferred linear draw process for forming container bodies of the invention; and 
     FIG. 7 is a schematic illustration taken along lines  7 — 7  of FIG.  6  and illustrates contoured draw rollers, which cooperate with inwardly curved portions of the mandrel on which the container bodies are formed. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will filly convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout. 
     FIG. 1 illustrates a preferred container  10  of the invention. As illustrated in FIG. 1, the container includes a container body portion  12  and a snap-on overcap  14  which includes an integral hinge  16 . As best seen in FIG. 3, the container body includes two opposed body wall portions  20  having inverse or radially inward curvature. As also seen in FIG. 3, the body wall  12  has an overall oblong shape defined by an elongate major axis  22  and a minor axis  24 , and corresponding end walls  25 ,  26 , and side walls  27 ,  28 . The inverse curvature body wall portions  20  are formed in the side walls, and are positioned symmetrically on opposing sides of the major axis  22 . Advantageously, the inverse curvature body wall portions  20  are positioned closer to one of the end walls, end wall  25 , than to the other end wall  26  of the container body. In this configuration, the two inverse curvature body wall portions  20  cooperate to form an integral handle for grasping of the container  10  by a user. 
     Returning to FIG. 3, it will be seen that each of the side walls  27 ,  28 , includes a nearly flat side body wall portion,  30 ,  32 . Preferably, such body wall portions have a slight outward curvature, which enhances the curl forming operation as discussed hereinafter. It is also preferred that the remaining body portions, including the nearly flat end wall  25 , be configured to have at least a slight outward curvature to allow curl formation using a conventional curling apparatus. 
     As best seen in FIG. 2, the container body wall  12  has a substantially uniform diameter and cross-section from top to bottom of the container body, i.e., vertically along the container body. Accordingly, the diameter and cross-section of the container body  12  at a location  40  near the top of the container body is substantially identical to the diameter and cross-section of the container body at a location  42  near the bottom of the container body. 
     The composite container body wall  12  can be constructed of a plurality of plies which usually include at least one body ply, a label ply, and a liner ply or coating. More particularly, as best seen in FIG. 5, the construction of the container body wall can include one or more paperboard body wall plies  50  and  52 , an exterior label ply  54 , and an interior liner ply or coating  56 . The liner ply or coating  56  preferably includes a polymer or metallic material of low moisture permeability, i.e., having a moisture permeability substantially less than that of the paperboard ply or plies, such as a flexible plastic film, metal foil, a plastic or metallic coating, or the like. More particularly, the liner ply  56  can be constructed of a polyethylene coated aluminum foil on a paper substrate, a polyethylene coated plastic film or metallicized film on a paper substrate, a plastic or metallicized film on a paper substrate, a hot melt adhesive sealable liner, etc. The body wall ply or plies  50 ,  52 , may comprise one or more plies of recycled or virgin paperboard. Preferably two body plies  50 ,  52 , are used. The label ply  54  can be formed from paper, an aluminum foil laminated paper layer, a polyethylene coated paper layer, a plastic film layer, etc. The composite container body wall  12  can also be constructed from a single wrap, multi-layer ply (not shown) which may be a pre-laminated coated and printed board or body layer with a polyethylene sealing layer thereon. Accordingly, the term, composite paperboard body wall, is used herein to mean a single or multi-ply body wall comprising a paperboard layer and at least one other layer formed of a paperboard or non-paperboard material. Preferably at least one layer is formed of a non-paperboard material. 
     As also illustrated in FIG. 5, the body wall is of substantially uniform thickness as a result of butt joint seams  60  and  62 . Accordingly the body wall is continuous in vertical cross-section, i.e., the body wall forming paperboard plies  50  and  52  are not overlapped substantially. A relatively thin outer label layer  54  is shown to have an overlapped outer portion seam  64 . However, the relatively thin nature of the outer label ply is such that the small overlap of seam  64  does not substantially decrease the uniform thickness of the body wall  12 . Although body wall  12  is shown to be formed from two paperboard plies  50  and  52 , it is within the scope of the invention to form the body wall from a single paperboard ply or from more than two paperboard plies as will be apparent to the skilled artisan. Advantageously, the body wall  12  can have a thickness ranging from about 0.01 inches (0.25 mm) to about 0.05 inches (1.3 mm), for example, about 0.3 inches, (0.75 mm). 
     This composite container body  12  is preferably formed by a linear draw process, discussed hereinafter, wherein plies are individually wrapped about a mandrel to create a tube having an axially extending seam. Preferably, the seams of the individual plies are staggered. As illustrated in FIG. 5, the liner layer seam  66 , the inner body ply seam  60 , the outer body ply seam  62 , and the label layer seam  64  each extend axially along the container body, parallel to one another. No two seams, however, are in circumferential alignment. Rather, according to a preferred embodiment of the invention, the liner layer seam  66  is positioned adjacent a center portion of one of the side or end walls. The position of the seam in this location is desired so as not to interfere with the curling operation of the beaded edge  72  of the composite container  10 . The inner body ply seam  62  may then be positioned in a circumferential location remote from the liner seam  66  and the outer body ply seam  60  may then be positioned in a circumferential location distant from the inner body ply seam  62 . Although the seams may be in alignment, it is preferred that they be staggered so as to avoid a particularly weakened area extending axially along the composite container  10 . The label ply seam  64  may then be positioned remote from the outer body ply seam  60  and, preferably, adjacent one of the curved corners of the container end walls. The label layer seam  64 , so positioned, will not interfere with any text or graphic design on the label layer  64 . If the composite container  10  is spirally wound or convolutely wound, it is also preferred that the seams be positioned in a staggered relationship. 
     FIGS. 2 and 4 illustrate the membrane closure member  70  and the outwardly curled beaded top edge  72  of the preferred container body construction. The membrane closure member  70  preferably has a shape corresponding to, and slightly larger than the cross-section of the container body (shown in FIG.  3 ), and is preferably hermetically sealed along the top surface  74  of the curled beaded top edge  72  to the interior liner layer or coating  56  (FIG. 5) by a heat sealing operation or the like as will be readily apparent to those of skill in the art, in order to protect the freshness of the contents of the container. The membrane closure member  70  is preferably a peelable layer that can be removed in whole or in part by peeling after removal of the snap-on overcap  14  (best seen in FIGS.  2  and  4 ). The membrane closure  70  can be constructed of any of various well known membrane closure materials including a composite material made of a plastic film layer, an aluminum foil layer, an adhesive layer, a paper layer, etc. and can be secured to the beaded top edge  72  by heat sealing, adhesive or other means. 
     In one preferred embodiment of the invention, best seen in FIG. 1, the snap-on overcap  14  includes an integral hinge  16  positioned near the end wall  26  of the. container body, that is distant from body wall portions  20  having inverse curvature and which cooperate to form an integral handle in the container body. The hinge  16  allows an end portion  82  of the snap-on overcap  14  to be opened for pouring of the contents of the container while the remaining portion  84  of the snap-on overcap  14  remains closed. 
     Returning to FIG. 4, the container body preferably includes a composite bottom closure member  78 . The bottom closure member  78  can be formed of the same composite materials utilized for the container body wall  12  or can be constructed of other materials. The bottom closure  78  can generally be cup shaped and secured to the container body wall  12  by an inwardly curled portion of the bottom of the container body wall  12 , and by heat sealing, adhesives, or other desired means. 
     The beaded top edge  72  of the container body  12  can be formed by conventional beaded or curling equipment well known to those of ordinary skill in the art to produce an outwardly beaded top edge. One particularly desirable curling apparatus is disclosed in U.S. Pat. No. 5,431,619 to Bacon et al. entitled Process and Apparatus for Forming an Outwardly Curled Lip on a Container Body which disclosure is incorporated herein by reference. 
     The snap-on overcap  14  can be injection molded from low density, linear low density, or high density polyethylene, or it can be thermoformed from a variety of plastic film materials, and can be of conventional construction, generally including a downwardly extending skirt having a configuration for snapping over and being secured around the beaded top edge  72  of the composite container body  12 . The resulting composite container  10  is suitable for packaging food or other products as described above and can be hermetically sealed. 
     FIGS. 6 and 7 illustrate a linear draw process for forming container bodies of the invention. As seen in FIG. 6, a plurality of continuous plies including two paperboard body wall plies  50  and  52 , a label ply  54  and a liner ply  56  are unwound in an unwinding zone  100  and are fed to an adhesive application zone  110  wherein interior surfaces of the plies are coated with adhesive by conventional means (not shown). In order to wrap the multiple plies around a stationary mandrel  120 , the plies are passed through a preforming zone  130  wherein curving of the plies is initiated by conventional paper folding guides or the like (not shown). 
     The multiple plies  50 - 56  are then fed to a shaped mandrel  120  and are drawn linearly along the mandrel by a plurality of drive rolls. As illustrated in FIG. 7, the drive rolls include two shaped rolls  142  having an outer contoured contact surface  144  of a curvature which matches the curvature of inversely curved portions  150  of the shaped mandrel  120 . As will be apparent to those of skill in the art, additional conventional drive rolls (not shown) are also positioned circumferentially around the mandrel  120 , to assist in the tubular body wall forming operation and to move the tubular body wall along the mandrel  120 . The continuous tubular container body is drawn along the mandrel by the drive rolls and is thereafter passed continuously from the mandrel to a conventional cutting zone (not shown) wherein the continuous container body is cut into a plurality of tubular body wall blanks by a conventional cutting operation. 
     The containers and container bodies according to the invention can be constructed and varied in numerous different ways as will be apparent to those of skill in the art. For example, a container body can include a plurality of opposed inwardly curved portions to thereby define a plurality of vertically separate container body portions or zones  200  and  210 , illustrated in FIG.  3 . The zones  200  and  210  can have different cross-sectional lengths as illustrated in FIG. 3, or a plurality of such zones can have substantially uniform cross-sectional lengths (not shown) in order to promote stacking of separate product elements such as cookies, crackers, or the like, in separate stacks in the container. Other variations and modifications of the invention will be apparent to those of skill in the art. 
     The invention has been described in detail with reference to its preferred embodiments. However, many modifications and other embodiments of the invention will come to mind to one skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the spirit and scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.