Patent Publication Number: US-8978922-B2

Title: Strengthened food container and method

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
     This application claims the benefit of U.S. Provisional Patent Application No. 61/647,144 titled “STRENGTHENED FOOD CONTAINER AND METHOD,” filed May 15, 2012, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to the field of containers. The present invention relates specifically to a metal food can having a non-cylindrical, strengthened sidewall. 
     SUMMARY OF THE INVENTION 
     One embodiment of the invention relates to a metal food can including a metal sidewall having an axial center point. The diameter of the sidewall varies at different axial positions along the sidewall. The can includes a can end coupled to an end of the metal sidewall, and a plurality of circumferential beads formed in the metal sidewall. The shape of each circumferential bead varies based upon the diameter of the section of the sidewall in which the beads are formed. 
     Another embodiment of the invention relates to a metal can for holding and storing food. The metal can includes a container end and a non-cylindrical metal sidewall. The metal sidewall includes a center section having a first diameter and an upper sidewall section located above the center section having a second diameter different than the first diameter. The upper sidewall section extends radially relative to the center section to provide the transition from the first diameter to the second diameter. The metal sidewall includes a lower sidewall section located below the center section having a third diameter different than the first diameter, and the lower sidewall section extends radially relative to the center section to provide the transition from the first diameter to the third diameter. The metal sidewall includes a plurality of circumferential beads formed in the metal sidewall each having a bead depth. At least one circumferential bead is formed in each of the center section, the upper sidewall section and the lower sidewall section. 
     Another embodiment of the invention relates to a method of forming a beaded metal food can. The method includes providing a cylindrical metal tube having an upper edge defining an upper opening and a lower edge defining a lower opening. The method includes forming a plurality of circumferential beads in the cylindrical metal tube. The method includes shaping the cylindrical metal tube to form a non-cylindrical metal sidewall, after forming the plurality of circumferential beads. 
     Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       This application will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, wherein like reference numerals refer to like elements in which: 
         FIG. 1A  is a front elevation view of a container, according to an exemplary embodiment; 
         FIG. 1B  is a top perspective view of the container of  FIG. 1A , according to an exemplary embodiment; 
         FIG. 2  is a sectional view along the longitudinal axis of the container of  FIG. 1A , according to an exemplary embodiment; 
         FIG. 3  is an enlarged view of a portion of the container shown in  FIG. 2 ; 
         FIG. 4  is a front elevation view of a container according to another exemplary embodiment; 
         FIG. 5  is a front elevation view of a container according to another exemplary embodiment; 
         FIG. 6  shows a method of making a container according to an exemplary embodiment; 
         FIG. 7  is an expanding mandrel that may be used during the manufacture of a container according to an exemplary embodiment; 
         FIG. 8  is a detailed sectional view showing an end wall attached to a sidewall via double seam according to an exemplary embodiment; 
         FIG. 9  is a sectional view taken along the longitudinal axis of the container of  FIG. 4  according to an exemplary embodiment; and 
         FIG. 10  is an enlarged view of a portion of the container shown in  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting. 
     Referring generally to the figures, various embodiments of a strengthened food container are shown. Specifically, the embodiments relate to metal food cans having a non-cylindrical sidewall and strengthening beads formed in the sidewall. In various embodiments, the containers discussed herein are configured to contain foods at a negative internal pressure (e.g., cans that have an internal vacuum) and the negative internal pressure results in an inwardly directed force on the sidewall of the can. The beads act to provide strength to the sidewall, and the beaded sidewalls discussed herein are configured to provide support to a non-cylindrical metal sidewall, particularly against the inwardly directed force. 
     Referring to  FIG. 1A  and  FIG. 1B , a container, shown as metal food can  10 , is shown according to an exemplary embodiment. Can  10  includes a first container end, shown as an upper end wall  12 , and a second container end, shown as lower end wall  14 . Can  10  also includes a sidewall  16 . Generally, upper end wall  12  is coupled to an upper end of sidewall  16 , and lower end wall  14  is coupled to a lower end of sidewall  16 . As shown, upper end wall  12  and lower end wall  14  are can ends designed to be removed using a tool, such as a can opener. 
     Sidewall  16  is a metal sidewall and is coupled to upper end wall  12  and lower end wall  14  via hermetic seams. A first seam  20  joins upper end wall  12  to sidewall  16 , and a second seam  22  joins lower end wall  14  to sidewall  16 . In the embodiment shown, seams  20  and  22  are hermetic double seams (shown in detail in  FIG. 8 ) formed of interlocked and crimped sections of the upper and lower edges of sidewall  16  and of the periphery of end walls  12  and  14 , respectively. 
     Generally, sidewall  16  is a non-cylindrical sidewall (e.g., a sidewall in which the cross-sectional shape varies at different positions along the axial length of the sidewall, a sidewall in which the cross-sectional area varies at different positions along the axial length of the sidewall, a sidewall having a generally circular cross-sectional shape, in which the cross-sectional diameter varies at different positions along the axial length of the sidewall, etc.). In the embodiments shown in the FIGS., sidewall  16  is a substantially circular shaped sidewall having different diameters at different axial positions along the length of the sidewall. Referring in particular to  FIG. 1A  and  FIG. 2 , sidewall  16  includes a center section, shown as center portion  24 , an upper sidewall section, shown as upper portion  26 , and a lower sidewall section, shown as lower portion  28 . Generally, center portion  24  is a centrally located portion of sidewall  16  in which the axial center point of the sidewall is located, upper portion  26  is a sidewall section extending from an upper end of center portion  24 , and lower portion  28  is a sidewall section extending from a lower end of center portion  24 . 
     In the embodiment shown, center portion  24  has a diameter D 1 , and in the embodiment shown, center portion  24  is a substantially cylindrical section such that D 1  remains constant, for at least a portion of the axial length of center portion  24 . Upper portion  26  extends upward from center portion  24  and extends radially outward relative to center portion  24 , and lower portion  28  extends downward from center portion  24  and extends radially outward relative to center portion  24 . Upper portion  26  includes a diameter D 2 , and lower portion  28  includes a diameter D 3 . As shown, both D 2  and D 3  are greater than D 1 . In this embodiment, upper portion  26  is outwardly angled and provides the transition from the small diameter of D 1  to the greater diameter of D 2 , and lower portion  28  is outwardly angled and provides the transition from the small diameter of D 1  to the greater diameter of D 3 . Thus, in this embodiment, the diameter of sidewall  16  increases from the upper end of center portion  24  to D 2 , and the diameter of sidewall  16  increases from the lower end of center portion  24  to D 3 . In other embodiments, D 1  may be greater than D 2  and/or D 3  such that the sidewall portions immediately above and/or below center portion  24  angle radially inward relative to the center section. In another embodiment, D 2  may be the same as D 1  such that both upper portion  26  and center portion  24  have substantially the same diameter and shape as each other, and in this embodiment, D 3  may be different from both D 2  and D 1  such that only lower portion  28  has a non-cylindrical shape. In another embodiment, D 3  may be the same as D 1  such that both lower portion  28  and center portion  24  have substantially the same diameter and shape as each other, and in this embodiment, D 2  may be different from both D 3  and D 1  such that only upper portion  26  has a non-cylindrical shape. 
     As shown in  FIG. 2 , sidewall  16  is shown prior to the attachment of upper and lower can ends  12  and  14 , and includes an upper flange  30  and a lower flange  32 . Upper flange  30  is an outwardly curled section of metal contiguous with the rest of sidewall  16  and is configured to be interlocked and crimped with an outer peripheral section of upper can end  12  to form seam  20  (shown in  FIG. 1A ). Lower flange  32  is an outwardly curled section of metal contiguous with the rest of sidewall  16  and is configured to be interlocked and crimped with an outer peripheral section of lower can end  14  to form seam  22  (shown in  FIG. 1A ). Upper section  26  continues to extend radially outward beyond the portion labeled D 2  to join to flange  30 , and lower section  28  continues to extend radially outward beyond the portion labeled D 3  to join to flange  32 . In other embodiments, both upper section  26  and lower section  28  may curve radially inward to join to flanges  30  and  32 , respectively. 
     In the embodiment shown, sidewall  16  is sized and shaped to be coupled to upper and lower can ends that have different diameters from each other. Sidewall  16  has an upper diameter D 4  and lower diameter D 5 , and upper and lower diameters D 4  and D 5  are selected such that the final, sealed can  10  has end walls of two different sizes. In the embodiment shown, D 4  is greater than D 5  such that the diameter of lower end wall  14  is smaller than the diameter of upper end wall  12 . In one embodiment, D 4  is 2.88 inches plus or minus a half inch, and in another embodiment, D 4  is 2.880 inches plus or minus 0.005 inches. In one embodiment, D 5  is 2.76 inches plus or minus a half inch, and in another embodiment, D 5  is 2.760 inches plus or minus 0.005 inches. 
     As shown in  FIG. 2 , the portion of upper sidewall section  26  extending from the upper end of center portion  24  to the location of D 2  is a substantially straight segment (e.g., non-curved, annular, etc.), and the portion of lower sidewall section  28  extending from the lower end of center portion  24  to the location of D 3  is a substantially straight segment (e.g., non-curved, annular, etc.). In other embodiments, upper sidewall section  26  and/or lower sidewall section  28  may include one or more curved sections. It should be understood, that the general shape and dimensions of sidewall  16  discussed herein refer to the shape and dimensions of the sidewall sections generally (e.g., if the shape and dimensions of the beads are ignored), and are not intended to relate to the localized shape and dimension variability introduced by the beads. For example, center portion  24  is generally cylindrical with a constant diameter if the localized variability of the beads in center portion  24  are ignored or averaged. The same applies to upper portion  26  and lower portion  28 . 
     In various embodiments discussed herein, can  10  includes a series of beads that act to strength the non-cylindrical of the can against inwardly directed forces. In the various embodiments discussed herein, beads are formed in the non-cylindrical portions of the sidewall and act to strengthen the sidewall against inwardly directed forces. In the embodiment of  FIG. 1A , can  10  includes a plurality of circumferential beads  40  formed in sidewall  16 . Generally, each bead  40  is a radially outwardly extending curved surface that extends radially outward relative to sidewall  16 . In various embodiments, can  10  includes at least two circumferential beads including at least one bead located in center portion  24  and at least one bead located in upper portion  26  and/or in lower portion  28 . Beads  40  act to strengthen sidewall  16  against radial loads that may occur due to the internal vacuum in can  10  and/or by the grip of a person holding can  10 . In various embodiments, can  10  is configured to hold contents at an internal vacuum of at least 28 pounds/square inch (gauge) or “psig,” and in another embodiment, can  10  is configured to hold contents at an internal vacuum of at least 22 psig. In other embodiments, can  10  is filled with food located with the internal cavity of can  10  and the can is sealed and has an internal vacuum of at least 22 psig, in one embodiment, and at least 28 psig, in another embodiment. In these embodiments, beads  40  are configured to strength non-cylindrical sidewall  16  against the radial inward force that results from the internal vacuum. 
     In various embodiments, sidewall  16  is made from metal of various thicknesses, and beads  40  are selected to strength non-cylindrical sidewall  16  against the radial inward force that results from the internal vacuum for the various thicknesses. According to various exemplary embodiments, sidewall  16  is formed from steel (e.g., tinplate, stainless steel, food grade tinplate, etc.) having a working gauge range of about 0.003 inches thick to about 0.012 inches thick, specifically of about 0.005 inches thick to about 0.009 inches thick, and more specifically, of about 0.0065 inches thick to about 0.0080 inches thick. In various embodiments, sidewall  16  is formed from steel having a thickness between 0.00684 inches thick and 0.00756 inches thick, specifically between about 0.00698 inches thick and 0.00756 inches thick, and more specifically is about 0.072 inches thick. 
     In various embodiments, for example as shown in  FIGS. 1A and 2 , can  10  includes a bead panel  42 . Bead panel  42  includes a plurality of continuous, radially outwardly extending beads  40 . In various embodiments, bead panel  42  is formed in the material of center portion  24 , upper portion  26  and lower portion  28 , such that bead panel  42  is a continuous beaded sidewall section extending from the non-cylindrical upper portion  26  through cylindrical center portion  24  and into non-cylindrical lower portion  28 . Thus, bead panel  42  includes beads  40  located on the cylindrical portion (e.g., center portion  24 ) and on the non-cylindrical or angled portions (e.g., upper portion  26  and lower portion  28 ) of sidewall  16 . 
     Referring to  FIG. 3 , a detailed view of center portion  24  and upper portion  26  of sidewall  16  is shown. As shown in  FIG. 3 , a radially inwardly extending curved bead  44  is located between each adjacent outwardly extending bead  40  in bead panel  42 . This configuration gives bead panel  42  a pattern of alternating outwardly extending beads  40  and inwardly extending surfaces, and in this embodiment, each outwardly extending bead  40  is contiguous with each adjacent inwardly extending bead  44 . In the embodiment shown, the outer surface of each bead  40  is a continuously curved surface that is concave relative to the longitudinal axis  34  of can  10 , and the outer surface of each inward bead  44  is a continuously curved surface that is convex relative to longitudinal axis  34 . As shown in  FIG. 1A , each inwardly extending curved bead  44  extends around the circumference of sidewall  16 . 
     In various embodiments, the shape (e.g., the depth, height, radius of curvature, the profile outline, etc.) of circumferential beads  40  varies at different axial positions along sidewall  16 . In one embodiment as shown in  FIG. 2 , the shape of at least one bead  40  located in upper sidewall portion  26  is different from the shape of at least one bead located in center portion  24 , and the shape of at least one bead  40  located in lower sidewall portion  28  is different from the shape of at least one bead located in center portion  24 . In various embodiments, the shape of beads  40  is a function of the diameter of sidewall  16  in which the beads are located. For example, in the embodiment shown in  FIGS. 2 and 3 , the shape of beads  40  is a function of the diameter of sidewall  16  at the location of the bead. 
     In various embodiments, the depth of each bead  40  (e.g., distance between the outermost point of an outward bead  40  and the inner most surface of the adjacent inwardly curved bead  44  measured in the direction perpendicular to longitudinal axis  34 ) is a function of the diameter of sidewall  16  in which the bead  40  is formed. Thus, in the embodiment shown in  FIG. 2 , the depth of beads  40  located in upper sidewall portion  26  is different than the depth of the beads  40  located in center sidewall portion  24 , and the depth of beads  40  located in lower sidewall portion  28  is different than the depth of the beads  40  located in center sidewall portion  24 . In general as shown in  FIG. 2 , the depth of at least one bead  40  in upper sidewall portion  26  is less than the depth of at least one bead  40  formed in center portion  24 , and the depth of at least one bead  40  in lower sidewall portion  28  is less than the depth of at least one bead  40  formed in center portion  24 . 
     In the embodiment shown in  FIG. 2 , both upper portion  26  and lower portion  28  are tapered sections having diameters that increase as the distance from the axial center point of can  10  increases. In this embodiment, the depth of beads  40  in both upper portion  26  and lower portion  28  decrease as the axial distance from the center point increases. Further, the depth of beads  40  in both upper portion  26  and lower portion  28  decrease as the axial distance to upper end wall  12  and lower end wall  14  decreases, respectively. In these embodiments, the depth of beads  40  decrease as the diameter of sidewall  16  at the location of the bead increases. 
     In various embodiments, the pitch of each bead  40  (e.g., the distance between the outer most points of adjacent outward beads measured in the direction parallel to longitudinal axis  34 ) is a function of the diameter of sidewall  16  in which the bead  40  is formed. Thus, in the embodiment shown in  FIG. 2 , the pitch of beads  40  located in upper sidewall portion  26  is different than the pitch of the beads  40  located in center sidewall portion  24 , and the pitch of beads  40  located in lower sidewall portion  28  is different than the pitch of the beads  40  located in center sidewall portion  24 . 
     Referring to  FIG. 3 , an enlarged view of center portion  24  and upper portion  26  is shown according to an exemplary embodiment. By way of example, outward bead  50  is a bead located in center portion  24  and outward bead  52  is a bead located in upper portion  26 . Bead  50  has a bead depth BD 1 , and bead  52  has a bead depth BD 2 . In one embodiment, depth BD 1  of bead  50  is the same before and after sidewall  16  is shaped into the non-cylindrical shape shown in  FIG. 2 , and depth BD 2  of bead  52  is less than the depth of bead  52  before shaping. 
       FIG. 3  shows a portion of a non-cylindrical sidewall in which the shape of the bead  40  varies based upon the diameter of the sidewall  16  at the location of the bead  40  according to an exemplary embodiment. In various embodiments, BD 2  is between 1% and 40% less than BD 1 , specifically between 5% and 30% less than BD 1  and more specifically is between 5% less and 20% less than BD 1 . In specific embodiments, BD 2  is between 10% and 20% less than BD 1  and more specifically is between 13% and 16% of BD 1 . 
     In various embodiments, BD 1  is between 0.015 and 0.035 inches, specifically between 0.020 and 0.030 inches and more specifically is between 0.023 and 0.027 inches. In various embodiments, BD 2  is between 0.011 and 0.031 inches, specifically is between 0.016 and 0.026 inches and more specifically is between 0.019 and 0.023 inches. 
     In various embodiments, BD 2  of bead  52  is different before and after shaping a metal tube into a non-cylindrical sidewall  16 . For example, in various embodiments, before shaping of upper portion  26  into the non-cylindrical shape, BD 2  is between 0.015 and 0.035 inches, specifically between 0.020 and 0.030 inches and more specifically is between 0.023 and 0.027 inches, and, in these embodiments, after shaping, BD 2  is between 0.011 and 0.031 inches, specifically is between 0.016 and 0.026 inches and more specifically is between 0.019 and 0.023 inches. 
     As noted above, bead pitch also varies based on the diameter of the sidewall  16  where the beads are located. By way of example, bead panel  42  includes an upper most outward bead  54  located in upper portion  26  at the uppermost end of bead panel  42 . Bead  50  has a bead pitch BP 1 , and bead  54  has a bead pitch BP 2 . In one embodiment, bead pitch BP 1  of bead  50  is the same before and after sidewall  16  is shaped into the non-cylindrical shape shown in  FIG. 2 , and pitch BP 2  of bead  54  is greater than the pitch of bead  54  before shaping. In various embodiments, BP 2  is between 0.5% and 15% greater than BP 1 , specifically between 0.5% and 10% greater than BP 1  and more specifically is between 1% and 5% greater than BP 1 . For the specific embodiment shown in  FIG. 3 , BP 2  is about 3.5% greater than BP 1  (plus or minus 0.5%). 
     In various embodiments, BP 1  is between 0.05 and 0.25 inches, specifically between 0.09 and 0.20 inches and more specifically is between 0.12 and 0.16 inches. In one specific embodiment, BP 1  is between 0.139 and 0.140 inches and more specifically is about 0.1396 inches. In various embodiments, BP 2  is between 0.05 and 0.25 inches, specifically between 0.09 and 0.20 inches and more specifically is between 0.12 and 0.16 inches. In one specific embodiment, BP 2  is between 0.140 and 0.141 inches and more specifically is about 0.1445 inches. In various embodiments, BP 2  is between 0.139 and 0.140 inches prior to shaping of upper portion  26  into the non-cylindrical shape, and BP 2  is between 0.140 and 0.0141 inches after shaping of upper portion  26  into the non-cylindrical shape. It should be noted that corresponding beads in lower portion  28  may be similarly shaped as beads  52  and  54  and the measurements, relative sizing and ratios discussed herein also relate to beads in lower portion  28 . 
     Referring to  FIG. 2 , in one embodiment, can  10  includes a bead panel  42  including 18 outwardly extending beads  40 . Further, bead panel  42  extends more than 50% of the axial length of sidewall  16 . However, in other embodiments, can  10  may include differently shaped bead panels. For example, as shown in  FIG. 4 , can  10  includes a bead panel  60  that includes eight radially outward extending beads  62 , and, as shown in  FIG. 5 , can  10  includes a bead panel  70  that includes six radially outward extending beads  72 . In various embodiments, the bead panel of can  10  may include between 4 and 24 beads, between 6 and 18 beads or between 8 and 18 beads. 
     Thus in the various embodiments, can  10  may include one or more outwardly extending beads on upper portion  26 , one or more outwardly extending beads on center portion  24  and one or more outwardly extending beads on lower portion  28 . In some embodiments, can  10  may include an unbeaded sidewall section between the beads of upper portion  26  and center portion  24 , and can  10  may include an unbeaded sidewall section between the beads of lower portion  28  and center portion  24 . In various embodiments, can  10  may include a bead panel that extends more than 25% of the axial length of sidewall  16 , and in other embodiments, can  10  may include a bead panel that extends more than 30% of the axial length of sidewall  16 . In various embodiments, can  10  may include a bead panel that accounts for between 25% to 75% of the axial length of sidewall  16 , and in other embodiments, can  10  may include a bead panel that accounts for between 30% to 60% of the axial length of sidewall  16 . 
     Referring back to  FIG. 1A , sidewall  16  of can  10  includes an alternating series of vertically positioned bands or facets. As shown, for example in  FIG. 1A , can  10  includes inwardly curved facets  46  spaced between outwardly curved facets  48 . Inwardly curved facets  46  and outwardly curved facets  48  are evenly spaced around sidewall  16  and extend substantially parallel to the vertical axis of can  10 . In one embodiment, can  10  includes ten inwardly curved facets  46  and nine outwardly curved facets  48 . In one embodiment, facets  46  and facets  48  are caused by an expanding mandrel which expands within sidewall  16  to form the noncylindrical shape of sidewall  16 . 
     Referring to  FIG. 6 , a method  100  of making can  10  is shown according to an exemplary embodiment. At step  102 , a rectangular piece of metal  104  is provided. At step  106 , a metal tube  108  is provided. In one embodiment, tube  108  is formed by rolling rectangular piece of metal  104  such that the lateral edges  110  and  112  are adjacent to each other and are welded together creating a welded seam  114  that extends vertically the axial length of tube  108 . At step  116 , tube  108  under goes a pre-shaping step in which an upper flared section  118  and a lower flared section  120  are formed such that tube  108  includes a substantially cylindrical sidewall  122  located between the upper and lower flared sections. 
     At step  124 , beads  126  are formed in the cylindrical sidewall  122 . In one embodiment, beads  126  are formed such that each bead has substantially the same bead depth and bead pitch as the other beads formed in cylindrical sidewall  122 . At step  130 , tube  108  is shaped to form non-cylindrical sidewall  16  including center portion  24 , upper portion  26  and lower portion  28 , discussed above. Thus, the shaping step that forms the non-cylindrical sidewall  16  occurs after beads  126  are formed into the material that becomes sidewall  16 . 
     In one embodiment, non-cylindrical sidewall  16  is formed using an expanding mandrel  132 , the shaped profile of which is shown in  FIG. 7 . Expanding mandrel  132  is shown in the expanded configuration in  FIG. 7 , and the expanded configuration is shaped to match the desired shape of non-cylindrical sidewall  16 . To shape the sidewall using mandrel  132 , mandrel  132  in the unexpanded stated is inserted into tube  108  shown at step  124 . Following insertion into tube  108 , mandrel  132  expands to the configuration shown in  FIG. 7  and in doing so, pushes tube  108  outward forming non-cylindrical sidewall  16 . 
     At step  140 , upper flange  30  and lower flange  32  are formed at the upper and lower ends of sidewall  16 . At step  142 , lower end wall  14  is coupled to the lower flange  32  via double seam  22 . A detailed view of double seam  22  is shown in  FIG. 8  and shows the seam formed from interlocked and crimped portions of material of both sidewall  16  and end wall  14 . Following attachment of lower end wall  14 , can  10  may be stored or shipped along with a separate upper can end  12 . Once can  10  is filled, for example filled with food at a packaging facility, upper end wall  12  is attached to sidewall  16  via double seam  22  hermetically sealing the food within can  10 . 
     Referring to  FIG. 9 , a cross-sectional view of can  10 , having bead panel  60  as shown in  FIG. 4 , is depicted according to an exemplary embodiment.  FIG. 10  shows an enlarged view of bead panel  60 . As shown in  FIG. 9  and  FIG. 10 , bead panel  60  includes eight radially outwardly curved beads  62  and nine radially inwardly curved beads  63 . Similar to the embodiment discussed above regarding  FIG. 2 , beads  62  and beads  63  extend through the center portion of the can sidewall onto the expanded upper and lower sidewall portions, and the shape, bead height and/or bead depth of beads  62  and beads  63  may vary based on the diameter of the sidewall at the location of the bead, providing increased strength to the can sidewall. 
     Referring to  FIG. 10 , bead  150  is a centrally located bead located in center sidewall portion  24  and has a bead depth BD 1  as discussed above. Bead  152  is an inwardly curved bead formed in upper sidewall portion  26 , and bead  154  is an inwardly curved bead formed in lower sidewall portion  28 . Bead  152  has a bead depth BD 3 , which is the radial distance measured between the radially innermost point of bead  152  and the upper edge of bead panel  60 . Bead  154  has a bead depth BD 4 , which is the radial distance measured between the radially innermost point of bead  154  and the lower edge of bead panel  60 . 
     In various embodiments, BD 3  is between 10% and 60% less than BD 1 , specifically between 20% and 50% less than BD 1  and more specifically is between 25% less and 40% less than BD 1 . In specific embodiments, BD 3  is between 30% and 40% less than BD 1  and more specifically is between 30% and 36% less than BD 1 . 
     In various embodiments, BD 1  is between 0.015 and 0.035 inches, specifically between 0.020 and 0.030 inches and more specifically is between 0.023 and 0.027 inches. In various embodiments, BD 3  is between 0.006 and 0.031 inches, specifically is between 0.010 and 0.020 inches and more specifically is between 0.013 and 0.019 inches. In a specific embodiment, BD 3  is about 0.016 inches. 
     In various embodiments, BD 3  of bead  152  is different before and after shaping a metal tube into a non-cylindrical sidewall  16 . For example, in various embodiments, before shaping of upper portion  26  into the non-cylindrical shape, BD 3  is between 0.015 and 0.035 inches, specifically between 0.020 and 0.030 inches and more specifically is between 0.023 and 0.027 inches, and, in these embodiments, after shaping, BD 3  is between 0.006 and 0.031 inches, specifically is between 0.010 and 0.020 inches and more specifically is between 0.013 and 0.019 inches. In a specific embodiment, BD 3  is about 0.016 inches after shaping. 
     In various embodiments, BD 4  is between 20% and 70% less than BD 1 , specifically between 30% and 60% less than BD 1  and more specifically is between 35% and 55% less than BD 1 . In specific embodiments, BD 3  is between 40% and 50% less than BD 1  and more specifically is between 43% and 46% less than BD 1 . In various embodiments, BD 4  is between 0.003 and 0.023 inches, specifically is between 0.07 and 0.019 inches and more specifically is between 0.010 and 0.016 inches. In a specific embodiment, BD 4  is about 0.013 inches. 
     In various embodiments, BD 4  of bead  154  is different before and after shaping a metal tube into a non-cylindrical sidewall  16 . For example, in various embodiments, before shaping of lower portion  28  into the non-cylindrical shape, BD 4  is between 0.015 and 0.035 inches, specifically between 0.020 and 0.030 inches and more specifically is between 0.023 and 0.027 inches, and, in these embodiments, after shaping, BD 4  is between 0.003 and 0.023 inches, specifically is between 0.07 and 0.019 inches and more specifically is between 0.010 and 0.016 inches. In a specific embodiment, BD 4  is about 0.013 inches, after shaping. 
     As shown in  FIG. 9 , bead panel  60  extends at least 20% but less than 80% of the axial length of the sidewall of can  10 . In one embodiment, bead panel  60  accounts between 30% and 40% of the axial length of the sidewall of can  10 , and more specifically accounts for about 37% of the axial length of the sidewall of can  10 . As noted above, bead panel  60  extends through center portion  24  and onto the expanded upper and lower sections of the can sidewall. 
     The containers discussed herein may be formed from any material, including metals, plastics, ceramics and glasses in various exemplary embodiments. According to an exemplary embodiment, the containers discussed herein are formed from metal, such as tin-coated steel or aluminum. In some embodiments, the containers discussed herein are formed from aluminum and the can ends are formed from tin-coated steel. In other embodiments, other metals or materials (e.g., polymers, high-temperature plastic, thermoplastics, cardboard, ceramic, etc.) are used to form some or all of the container. 
     Containers discussed herein may include containers of any style, shape, size, etc. For example, the containers discussed herein may be shaped such that cross-sections taken perpendicular to the longitudinal axis of the container are generally circular. However, in other embodiments the sidewall of the containers discussed herein may be shaped in a variety of ways (e.g., having other non-polygonal cross-sections, as a rectangular prism, a polygonal prism, any number of irregular shapes, etc.) as may be desirable for different applications or aesthetic reasons. In various embodiments, the sidewall of can  10  may include one or more axially extending sidewall sections that are curved radially inwardly or outwardly such that the diameter of the can is different at different places along the axial length of the can, and such curved sections may be smooth continuous curved sections. In one embodiment, can  10  may be hourglass shaped. Can  10  may be of various sizes (e.g., 3 oz., 8 oz., 12 oz., 15 oz., 28 oz, etc.) as desired for a particular application. 
     Further, a container may include a container end (e.g., a closure, lid, cap, cover, top, end, can end, sanitary end, “pop-top”, “pull top”, convenience end, convenience lid, pull-off end, easy open end, “EZO” end, etc.). The container end may be any element that allows the container to be sealed such that the container is capable of maintaining a hermetic seal. In an exemplary embodiment, the upper can end may be an “EZO” convenience end, sold under the trademark “Quick Top” by Silgan Containers Corp. 
     The upper and lower can ends discussed above are shown coupled to the can body via a “double seam” formed from the interlocked portions of material of the can sidewall and the can end. However, in other embodiments, the can ends discussed herein may be coupled to the sidewall via other mechanisms. For example, can ends may be coupled to the sidewall via welds or solders. As shown above, the containers discussed herein are three-piece cans having an upper can end, a lower can end and a sidewall each formed from a separate piece of material. However, in other embodiments, a two-piece can (i.e., a can including a sidewall and an end wall that are integrally formed and a separate can end component joined to the sidewall via a double seam) may be provided with an internal strainer as discussed herein. 
     In various embodiments, the upper can end may be a closure or lid attached to the body sidewall mechanically (e.g., snap on/off closures, twist on/off closures, tamper-proof closures, snap on/twist off closures, etc.). In another embodiment, the upper can end may be coupled to the container body via an internal vacuum. The container end may be made of metals, such as steel or aluminum, metal foil, plastics, composites, or combinations of these materials. In various embodiments, the can ends, double seams, and sidewall of the container are adapted to maintain a hermetic seal after the container is filled and sealed. 
     The containers discussed herein may be used to hold perishable materials (e.g., food, drink, pet food, milk-based products, etc.). It should be understood that the phrase “food” used to describe various embodiments of this disclosure may refer to dry food, moist food, powder, liquid, or any other drinkable or edible material, regardless of nutritional value. In other embodiments, the containers discussed herein may be used to hold non-perishable materials or non-food materials. In various embodiments, the containers discussed herein may contain a product that is packed in liquid that is drained from the product prior to use. For example, the containers discussed herein may contain vegetables, pasta or meats packed in a liquid such as water, brine, or oil. 
     During certain processes, containers are filled with hot, pre-cooked food then sealed for later consumption, commonly referred to as a “hot fill process.” As the contents of the container cool, a vacuum develops inside the container. In embodiments using a vacuum attached closure, the resulting vacuum may partially or completely secure the closure to the body of the container. During other processes, containers are filled with uncooked food and are then sealed. The food is then cooked to the point of being commercially sterilized or “shelf stable” while in the sealed container. During such a process, the required heat and pressure may be delivered by a pressurized heating device or retort. 
     According to various exemplary embodiments, the inner surfaces of the upper and lower can ends and the sidewall may include a liner (e.g., an insert, coating, lining, a protective coating, sealant, etc.). The protective coating acts to protect the material of the container from degradation that may be caused by the contents of the container. In an exemplary embodiment, the protective coating may be a coating that may be applied via spraying or any other suitable method. Different coatings may be provided for different food applications. For example, the liner or coating may be selected to protect the material of the container from acidic contents, such as carbonated beverages, tomatoes, tomato pastes/sauces, etc. The coating material may be a vinyl, polyester, epoxy, EVOH and/or other suitable lining material or spray. The interior surfaces of the container ends may also be coated with a protective coating as described above. 
     Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only. The construction and arrangements, shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention. 
     While the current application recites particular combinations of features in the claims appended hereto, various embodiments of the invention relate to any combination of any of the features described herein whether or not such combination is currently claimed, and any such combination of features may be claimed in this or future applications. Any of the features, elements, or components of any of the exemplary embodiments discussed above may be used alone or in combination with any of the features, elements, or components of any of the other embodiments discussed above. 
     In various exemplary embodiments, the relative dimensions, including angles, lengths and radii, as shown in the Figures are to scale. Actual measurements of the Figures will disclose relative dimensions, angles and proportions of the various exemplary embodiments. Various exemplary embodiments extend to various ranges around the absolute and relative dimensions, angles and proportions that may be determined from the Figures. Various exemplary embodiments include any combination of one or more relative dimensions or angles that may be determined from the Figures. Further, actual dimensions not expressly set out in this description can be determined by using the ratios of dimensions measured in the Figures in combination with the express dimensions set out in this description.