Blank and forming tool for forming a container
View Patent ↗A blank for being formed into a container. The blank has a marginal area that includes a plurality of score lines for facilitating forming of the blank into the container. The score lines are positioned to facilitate formation of the container. A forming tool has features to facilitate forming the blank into the container.
1. A method of forming a container from a blank, the method comprising:
obtaining a tool, the tool comprising a first tool assembly having a nose having an external surface shaped to correspond to at least a portion of the container, a second tool assembly having a cavity block having a recess shaped to correspond with at least a portion of the container and formed by an external surface of the cavity block that generally corresponds to the shape of the container, the external surface of the cavity block comprises a bottom surface, a side surface extending upwardly from the bottom surface, a flat upper surface that is parallel to the bottom surface, and a curved surface that extends between the side surface and the flat upper surface;
obtaining a circular blank comprising a plurality of radial score lines, at least one cross-direction portion along a cross-direction of the blank, and at least one machine-direction portion along a machine-direction of the blank, a different number of radial score lines of the plurality of radial score lines are arranged on the at least one cross-direction portion of the blank than a number of radial score lines arranged on the at least one machine-direction portion of the blank;
operating at least one of the first tool assembly and the second tool assembly is moved to an open position wherein the first tool assembly and the second tool assembly are spaced apart;
positioning the blank between the first tool assembly and the second tool assembly;
forming the blank into the container by operating at least one of the first tool assembly and the second tool assembly is moved to a closed position wherein the blank is pressed between the first tool assembly and the second tool assembly and the nose is at least partially received in the cavity block, the forming the blank into the container comprises forming a bottom wall of the container by pressing the blank against the bottom surface, forming a side wall of the container by pressing the blank against the side surface, forming a flange of the container by pressing the blank against the flat upper surface, the flange being parallel to the bottom wall, and forming a transition between the flange of the container formed from the blank and the side wall of the container formed from the blank by pressing the blank against the curved surface, the transition between the flange and the side wall being curved to correspond to the shape of the curved surface.
2. The method of claim 1 wherein the curved surface has a radius of at least about 0.05 inches.
3. The method of claim 1 wherein the blank comprises a central portion, an outer edge, and a marginal portion between the outer edge and the central portion.
4. The method of claim 3 wherein the blank comprises a radius extending from a center of the blank to the outer edge, the marginal portion of the blank comprises the plurality of radial score lines having an angular spacing between respective adjacent radial score lines, the plurality of radial score lines comprising a plurality of first radial score lines and a plurality of second radial score lines, the first radial score lines each having a respective first length and the second radial score lines each having a respective second length, the first length being less than the second length, the machine direction corresponds to the feed direction of the blank into the forming tool and the cross-direction is perpendicular to the machine direction, the marginal portion comprises the at least one cross-direction portion and the at least one machine direction portion and comprises a first cross-direction portion at one cross-directional end of the blank, a second cross-direction portion at a second cross-directional end of the blank, a first machine-direction portion at one machine directional end of the blank, and a second machine-direction portion at a second machine-directional end of the blank,
the blank comprises weakening features in each of the first cross-direction portion and the second cross-direction portion for weakening the blank to promote stretching of the blank in the first cross-direction portion and the second cross-direction portion, and strengthening features in each of the first machine-direction portion and the second machine-direction portion for strengthening the blank to resist stretching of the blank in the first machine-direction portion and the second machine-direction portion, the weakening features comprise the plurality of first radial score lines and at least a portion of the plurality of second radial score lines, the strengthening features comprise at least a portion of the plurality of second radial score lines, and the strengthening features are free from any of the first radial score lines in the first machine-direction portion and the second machine-direction portion.
5. The method of claim 4 wherein in each of the weakening features each of the plurality of first radial score lines are adjacent to and spaced apart from a respective one of the second radial score lines by a first angular spacing.
6. The method of claim 5 wherein each of the second radial score lines being adjacent to another of the second radial score lines and being spaced apart from a respective one of the second radial score line by a second angular spacing, the second angular spacing being greater than the first angular spacing.
7. The method of claim 4 wherein the first cross-direction portion having the same quantity of first and second radial score lines as the second cross-direction portion.
8. The method of claim 7 wherein the first machine-direction portion has the same quantity of second radial score lines as the second machine-direction portion.
9. The method of claim 4 wherein the combined quantity of first and second radial score lines in each of the first and second cross-direction portion is greater than the quantity of second radial score lines in each machine-direction portion.
10. The method of claim 4 wherein each of the first radial score line and the second radial score line extend from the outer edge of the blank to a location adjacent the central portion of the blank.
11. The method of claim 3 wherein the forming the blank into the container comprises forming the bottom wall from the central portion, forming the side wall extending upwardly from the bottom wall from at least a portion of the marginal portion of the blank, and forming the flange extending laterally outward from the side wall from at least a portion of the marginal portion of the blank.
12. The method of claim 11 wherein the bottom wall is generally circular and the container is a tray with the top surface of the flange corresponding to a top surface of the tray.
13. The method of claim 11 wherein the transition comprises an upper corner that connects the side wall to the flange, the upper corner being a curved portion of the container.
14. The method of claim 13 wherein the upper corner comprises the transition formed at the curved surface of the tool.
15. The method of claim 1 wherein the external surface of the nose has a flat surface parallel to the flat upper surface, the forming the flange of the container comprises contacting the blank with the flat surface of the nose and pressing the blank against the flat upper surface of the cavity block.
16. The method of claim 1 , wherein, the number of radial score lines of the plurality of radial score lines arranged on the at least one cross-direction portion of the blank is greater than the number of radial score lines arranged on the at least one machine-direction portion of the blank.