Abstract:
The present invention relates to a method of making a container body ( 8 ), comprising the steps of: i) providing a round container body ( 8 ); ii) forming at least one circumferential bead ( 2 ) in the container body ( 8 ); and iii) axially compressing the container body ( 8 ) to kink and axially close the kinked bead ( 10 ), and to such container body ( 8 ) and container comprising same.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is the United States national phase of International Application No. PCT/EP2012/055690 filed Mar. 29, 2012, and claims priority to European Patent Application No. 11160650.5 filed Mar. 31, 2011, the disclosures of which are hereby incorporated by reference in their entireties. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a method of making a container body, to a container body as such, and to a container comprising such container body. 
     2. Description of Related Art 
     Metal containers are used for packaging food and non-food, as well as beverages such as pressurized beverages. Such containers may have a diameter in the range of 40-150 mm, such as 96 mm and 127 mm. With an increase of diameter, the thickness of the metal walls is to be increased as well in order to allow for sufficient axial strength and for sufficient resistance to radial compression. Presently there is a high demand for using smaller thicknesses for making containers in order to cut costs for metals used. 
     Accordingly, the present invention has for its object to provide a container body for a container, which container body will have a sufficiently high axial strength and in particular a high resistance to radial compression although made from thinner metal materials. 
     SUMMARY OF THE INVENTION 
     Thereto, the present invention provides a method of making a container body, comprising the steps of:
         i) providing a round container body;   ii) forming at least one circumferential bead in the container body; and   ii) axially compressing the container body to kink and axially close the kinked bead.       

     The present invention is based on the insight, that by providing a container body with a circumferential bead, which is thereafter axially compressed such that the kinked and closed bead will impart the container body with an improved resistance to radial compression. If in addition, the bead is folded towards the wall of the container body, will result in an additional improvement of the resistance to radial compression. Such a container may be produced in an elegant manner, because it is essentially sufficient, that after the application of the circumferential bead into the wall of the container body, that axial compression of the container body will result in the desired kinking and bead closure. Preferably the kinked bead is also closed such extent that it appears that in the container wall there is present a small slit, which may be even no longer be accessible because the wall is touching at this slit. If the bead extends outwardly, then the bead is not or substantially not accessible from the interior of the container. When extending inwardly, then there is no or substantially no access from the outside. The properties of such a container body are improved such, that it is possible to produce such a container with these properties using thinner material, such as instead of material having a thickness of 0.22 mm or 0.25 mm. Use can be made of what is called bulk thicknesses for beverage cans, being a material having a thickness of 0.12 mm or 0.14 mm. 
     It is noted that the effect of the present invention is obtained irrespective the type of container body or container. Accordingly, the container body may have the form of a sleeve of which both ends are to be provided with an end wall, or the container body may have been provided with an end wall at one body end, such as by drawing and ironing or by any other suitable manner like seaming, soldering and the like. In addition, the container body and ultimate container may have a circumferential shape being circular, oval, rounded, angular like square, triangle, or polygonal, and combinations thereof. 
     The improvement in resistance to radial compression is highest in the middle section of the container body. Accordingly, it is preferred to provide the container body in its middle section with the bead which is subsequently to be kinked and closed. Still, it is possible to provide the bead or other beads in other sections in the container body, such as in a section where a picture or drawing on the outer surface of the container, is to be separated from imprinted wording, such as a manual or advertisement. Otherwise, it is possible to bring intentionally divisional lines in a picture or in a information printing on the outside, thereby attracting the attention of the consumer to specific areas on the container surface. It will be appreciated that by making one or more of these kinked beads in the container wall, the changed appearance will be improving the aesthetic properties of the container, in particular when the ultimate container has a glossy outer surface (coating). 
     When the bead is formed in the container body and extends outwardly from the container body, then according to an alternative embodiment, the kinked bead may be radially inwardly compressed to an extent that the kinked and compressed part of the container body lies within the hypothetical confinement of the container body so that the outer surface is flush and thus not comprise an outwardly extending structure. 
     It is noted that the bead is extending circumferentially of the container but it is not necessary that the bead extends over the entire circumference of the container body, so that the container body comprises alternating beaded and original container body surface. 
     Due to the axial compression, the bead will kink and thereby deform. Kinking will be initiated, when at a particular side of the bead the so called kinking point is surpassed, where after the material will fail and deform by kinking. This means, that when a symmetrical bead is used kinking may start at both sides independently or concomitantly. If it is desired to control the side of of the bead where kinking will occur and thereby the direction in which the deformation of the bead will proceed, it is preferred that when the bead has a symmetrical shape, in step iii) kinking is initiated at one side of the symmetrical bead. 
     In the alternative, when using an asymmetrical shaped bead, then the direction of kinking and folding of the kinked bead is controlled when preferably the bead has an asymmetrical shape such that the kinking force is different at both bead sides. Kinking will then occur at the side of the bead where the kinking point is first surpassed. 
     The kinked bead will project from the inside or outside of the container body wall, dependent on whether the bead was initially formed inwardly or outwardly of the container body wall. If it is desired, that the extent of projection length is to be minimized, then it is preferred that the kinked bead is radially compressed. Still, the improvement in resistance to radial compression is maintained. 
     Generally the circumferentially extending bead may have the form of a horizontally extending straight bead. However, it is also possible that the bead has the form of a serpentine bead which serpentines along the circumference around the container body in a regular (harmonic) or irregular manner. Accordingly, after kinking, the bead will show a wavy (serpentine) line extending around the circumference. In the alternative, the bead may have a wavy form, of which bead width is not constant but changes with the wavy form so that the width of the bead is increasing and decreasing (regularly or irregularly) to nearly a minimal bead width. The minimal bead width, is required such that during the kinking, at those minimal width parts of the bead will be closed or contact in between the bead walls, thereby forming a partially closed bead. However, at locations around the circumference where the width of the bead is larger than the minimal bead width, the bead will not be closed by the kinking and will show over the circumference closed bead parts and open bead parts. This is for many customers an aesthetically beneficial form. Similarly, the bead may have a so-called ornamental form, which means, that over the circumference the bead will have a structure or form which is repeating over the circumference, but in between the bead walls there is a minimal bead width, so that when the bead is kinked and (partially) closed, the result will be an ornamental presentation, such as having the form of a four leave clover. Obviously, many different ornamental type of structures may be possible within the ambit of the present invention. Relevant is, that an open bead is formed with a particular structure, such that after the kinking and (partially) closing of the bead an ornamentally appreciated form is obtained. Instead of a four leave clover form, it is also possible to provide overlapping or adjacent dimples over the circumference, such that after kinking is formed a chain of dimples which may extend inwardly and/or outwardly thereby providing a particular structure that may be sensitized by feeling from the outside. Obviously several types of beads may be present in one and the same container body within the ambit of the present invention. 
     The inwardly extending kinked bead may also form a support for an insert piece which will be snapped or connected to the inwardly kinked bead. For instance a metering structure may be formed within the interior of the container. Such a metering structure can be used for metering the amount of food, such as baby food to be taken with a spoon from the container comprising a container body according to the present invention, but also stripping paint and the like is possible. 
     When the container body is also to be radially expanded during the formation of the container, and the kinked bead is projecting inwardly from the container body wall, then it is preferred that the kinked bead is radially compressed during the radial expansion of the container body. 
     When the outer surface of the ultimate container body is to be provided with printed information, then the aesthetic properties of the container is highly improved if preferably the step of providing printed information on the outside of a perform for the container body, which printed information is separated from a container body section in which the circumferential bead is to be formed. This printed information (or illustration or picture) forming a so called field of information is extending beyond and thus divided by a bead according to the invention, then it is preferred for maintaining the highly aesthetic properties that preferably the printed information present at both sides of the closed and kinked bead is provided in a flushing (non-interrupted) manner. 
     Another aspect of the invention relates to a container, comprising a container body provided with at least one circumferential axially closed and kinked bead. As indicated before it may be advantageous that the kinked bead is radially compressed and that such compression may take place during the radial expansion of the container body. Similarly, when the container is to be provided with information printed over and separated by a kinked bead according to the invention, it is preferred that such printing has taken place in a so called flushing manner. Accordingly, the reading of the information is not optically separated by the bead. 
     In this respect it is noted that the kinked and closed bead is such that the slit in between both sides of the closed bead may be minimal or even not present anymore. In the latter situation, because for instance a coating provided on the outside of the container will ultimately close the slit. Accordingly, there is an appearance of the container of a very minor bead although inwardly there is a larger kinked and folded bead that will support the increase of the resistance to radial compression. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Mentioned and other features of the container body, container and method of making such container body will be further appreciated by a description of several embodiments of the container, of the container body and of the method of making the container, although the description is not intended to limit to any extent the scope of the present invention. In relation to the description reference will be made to drawings, wherein: 
         FIGS. 1A-E  show various stages of the method of making a container body according to the invention; 
         FIG. 2  shows a cross-section of a perform of a container according to the invention; 
         FIGS. 3A-E  show various stages of kinking and axially closing a bead present in the container body preform shown in  FIG. 2 ; 
         FIG. 4  is a cross-section of another preform for a container body according to the invention; 
         FIGS. 5A-C  show various stages of the kinking and closing of the bead formed in the perform for the container body shown in  FIG. 4 ; 
         FIG. 6  shows an alternative to the formation of two beads in different directions in the wall of a container body; 
         FIGS. 7A-C  show the radial compression of a bead shown in  FIG. 5C  or  FIG. 6 ; 
         FIGS. 8A-D  show the compression of a kink bead by radial expansion of the container wall; 
         FIG. 9  shows the use of an outwardly extending kinked and compressed bead as a part of a snapping connection with a container cap; 
         FIG. 10  shows the preform of  FIG. 2 ; 
         FIGS. 11A-D  show an alternative manner for making a closed bead. 
         FIGS. 12A and 12B  show a serpentining bead extending over the circumference in the open form ( FIG. 12A ) and in kinked form ( FIG. 12B ); 
         FIGS. 13A and 13B  show a wavy bead with increasing and decreasing bead width in the open form ( FIG. 13A ) and in kinked form ( FIG. 13B ); 
         FIGS. 14A and 14B  show an ornamental bead in the open form ( FIG. 14A ) and closed form ( FIG. 14B ) giving the impression of a four leaf clover; 
         FIGS. 15A-15C  show a bead in the form of neighbouring dimples formed after kinking and closing ( FIG. 15B ) the bead and extending inwardly, and  FIG. 15C  extending outwardly; 
         FIGS. 16A-16C  show in perspective and cross sectional views the use of an insert connected to a kinked bead; and 
         FIG. 17  shows a container comprising a container body of the invention being kinked and radially inwardly compressed. 
     
    
    
     DESCRIPTION OF THE INVENTION 
       FIG. 1A  shows a strip of metal, such as steel, tin plated steel or aluminium. The strip is printed with information fields  3 - 5  to be separated by the two beads  2  (see  FIG. 1D ). Subsequently, the strip  1  provided with the information fields  3 - 5  is formed into a cylindrical shape ( FIG. 1C ). Thereafter, the edges  6  of the cylindrically formed strip  1  are welded together and provided with a welled line  7 . 
     Thereafter, the welded and cylindrically formed container body  8  is provided with two circumferential beads  2  extending in between the information fields  3 - 5 . Finally, the container body is subjected to axial compression following the arrows  9 . This results in a kinking and axial closing of the kinked bead, thereby forming a circumferential, axially closed and kinked bead  10 . It is shown  FIG. 1E , that the closed bead  10  extends over a very minor part of the height of the container body  8 , so that the information fields  3 - 5  are now abutting and almost flushing without any separation. Still, at the inside of the container body  8  the inwardly projecting kinked and folded bead  10  is still appreciable. 
     As stated above the container body may have been produced by different manners and may have been provided with an end wall in advance, such as before the bead formation and/or the axial compression. 
     Hereafter the kinking and axial closing and folding of the kinked bead will be further described in detail by way of various embodiments according to the invention. 
       FIG. 3  shows in cross-section a container body  11  that is provided with two symmetrical beads  12  both extending at about ⅓ from either end of the container body  11 . 
       FIG. 3A  shows in more detail the symmetrical bead  12 . When axially compressing this container body  11  from both ends, the bead  12  may kink and fold towards either end of the container body dependent on whether the so called kinking point is surpassed first at one or the other side of the symmetrical bead  12 . In order to control the direction in which the kinking of the bead  12  will occur, it is shown in  FIG. 3B , that during axial compression according to the arrows  13 , before or at the same time a tool  14  is pressing against the side  15  of the bead  12  thereby surpassing the kinking point at this side  15 . This has as a result that the kinking of the bead  12  will take place in the direction of the arrow  16  so that the folded part  17  of the original bead  12  will extend in this case downwardly in that direction from which the tool  14  was approaching side  15  of the bead  12 . Retraction of the tool  14  according to the arrow  18  ( FIG. 3C ) will result in a formed closed and kinked bead  19  as shown in  FIG. 3D . The bead  19  is closed because a slit near the location  20  is almost occupied by the material of the container body wall  21 . Finally, using a tool  22 , the kinked and closed bead  19  is radially compressed thereby reducing to the extent over which the bead  19  extends to the interior of the now formed container body  23 . It is noted that the direction of folding the bead may be chosen in relation to the content of the ultimate container, and/or whether the bead may serve as a support, such as a measuring spoon, or closure part (see hereafter). 
       FIG. 4  shows in cross-section another preform  24  for a container body according to the invention. In this preform are formed asymmetrical beads  25  extending over the circumference of the perform  24 . 
     As shown in  FIG. 5A , bead  25  is asymmetrical which implies in relation to the bead  25  that at the location  26  the radius is smaller, such as 0.7 mm, than at the location  27  where the radius may be 1.25 mm. This means, that upon axial compression according to the arrow  30  the kinking point will be surpassed at a lower axial compression force for the location  26  where the bead  27  will fail or kink first. This results in a folding in the downward direction according to arrow  28  in which direction the part  29  will fold (see  FIG. 5B ). Continuation of the compression force will result in a closure of a gap  30  thereby forming the kinked and axially closed bead  31  according to the invention. As shown by the level lines  32  and  33 , the kinking and closing of the bead  25  will result in a reduction of the height of the original preform  24 . Formed is the container body  34  having a similar appearance as the container body  8  shown in  FIG. 1E . 
       FIGS. 7A-C  show a further manipulation of the bead  31  of the invention, as was shown in  FIG. 5C , and extending inwardly of the container body  34 . In the situation shown in  FIGS. 7A-C , the bead  31  extends outwardly of the container body  35 . The bead  31  is subjected to a radial compression using tools  36  and  37 . The tool  36  is provided with a cavity  38  which is intended to receive and accommodate the bead  31 .  FIG. 7B  shows the end of the radial compression operation with the tools  36  and  37  in closed position, thereby forming a compressed bead  39  substantially filling the cavity  38 . The bead  39  comprises a horizontal hairpin  40  and two layered vertical hairpins  41  and  42 . Although initially extending outwardly of the container body  35 , due to the radial compression with a tool  36  being at the inside of the container body and provided with the cavity  38 , the ultimate bead  39  is again extending inwardly of the container body  35  so that its outer surface  43  is substantially not interrupted. 
       FIGS. 8A-D  show a container body  44  comprising the bead  39  which is again extending inwardly of the container body. The container body  44  is subjected to radial expansion using an expansion tool  45 . The situation after radial expansion of the section comprising a bead  39  is shown in  FIG. 8C . The effect is that the now formed bead  46  extends radially outwardly on the outer surface of the container body  44 . 
       FIG. 9  shows the upper part of a container  47  comprising its upper section a radially outwardly extending bead  39 . This bead  39  is used for mounting and connecting via a snapping connection a cap  48  onto the container body  44 . 
       FIG. 10  shows a cross-section of the same preform  11  as shown in  FIG. 2  and comprising the bead  12 . As shown in  FIGS. 11A-D , this circumferential and symmetrical bead  12  is subjected to radial compression with the tools  49  moving in the direction of the arrows  50 . This results in a closing of a gap  51  of the bead  12  allowing a proximal head like section  52  in the ultimate bead  53 . Accordingly, it is avoided that particularly in the section  52  cracking would occur and thereby would be formed an open connection in between the inside of the container body or container  54  and the outside. 
       FIGS. 12A and 12B  show a container body  55  comprising a bead  56  having a wavy structure. The wavy form may be harmonious or irregular as desired over the circumference.  FIG. 12B  shows the same container body  55 , but the bead  56  is now in its kinked form whereby the bead  56  is closed. The result is a wavy line  57  extending over the circumference of the container body  55 . 
       FIGS. 13A and 13B  show an alternative bead  58  according to the invention which has a region  59  with a bead width W which is minimal and a region  60  with a bead width W which is maximal. Change in bead width W may be gradual but may also be abruptly, and non-harmonious.  FIG. 13B  shows, that in the region  59  the bead is closed and that the bead width W is nearly minimal or not present. In the region  60  the width of the bead  58  is now less than the bead width W of the section  60  in  FIG. 13A . Accordingly, there is formed a bead  58  with bead parts  61  that are closed and bead parts  62  that still have an inwardly open structure. Both bead parts  61  and  62  may be repeating over the circumference in a regular or irregular manner. 
       FIGS. 14A and 14B  show an ornamental bead  63  according to the invention. The bead  63  is having the form of alternating lobes  64  in combination with adjacent smaller lobes  65  which are connected via a section  66  with smallest bead width W. After kinking the bead  63  is closed in the sections  66 , the kinked bead  63  having a bend line, provides an impression of a row of four leave clovers. 
       FIGS. 15A-15C  show a container body  67  with an alternative bead  69  comprising a row of open dimples  70  formed in the upper section  71  and lower section  72  of the container body  67 . After kinking according to the arrows  68  the bead  69  is formed into a row of dimples  74  which may extend inwardly and having a bend line ( FIG. 15B ) or outwardly ( FIG. 15C ) when the initial dimples  70  extend outwardly having in cross section the form of the bead of  FIG. 3E . When extending outwardly the row of dimples  74  provides a sensation of a row of dimples. When extending inwardly the beads  74  provides the sensation of a row of indents. 
       FIG. 16A  show a container body  75  provided with a kinked and closed bead  76  with an inwardly extending free end  77  with in cross section a spherical form. A plastic insert  78  is having a cavity  79  which is complementary in cross section to the spherical form of the free end  77 . The insert  78  extends over a part of the circumference of the free end  77  and covers a part of the opening  80  thereby forming a free edge  81  which can be used for metering material taking with a spoon from the interior of the can body  75 , or stripping paint from a brush which was dipped into paint present in the container body  75 . 
     Finally,  FIG. 17  shows a container  81  comprising a container body  82 . The container body is provided with a kinked and radially compressed bead  39  (as described in relation to  FIGS. 7A to 7C ) and a bead  53  (as described in relation to  FIGS. 11A to 11D ). The bead  39  is present for increasing the strength of the container body  82 , but also for providing boundaries for different types of information printed in the sections  83 ,  84  and  85 . The bead  53  also provides strength to the upper part of the container body and provides support for a foil  86  closing of the content of the container  81  and carries a metering spoon  87 . The container  81  is closed by a cap  88 .