JPH075127B2 - Cans for canning - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a can for cans, and more particularly, it has excellent resistance to deformation under reduced pressure during the cooling process after filling and sterilizing the contents or during the subsequent storage. The present invention relates to a can for can whose material used can be made thinner.

[0002]

2. Description of the Related Art Conventionally, as a material for a can for canning, a metal plate has been mainly used in view of gas barrier property, heat resistance, pressure resistance, etc. A so-called three-piece can or metal plate formed by joining opposite end line parts by means such as welding, adhesion or soldering to form a side canned can body, and fastening both ends of the can body to the top and bottom lid. Attached to the bottomed can body for deep drawing or ironing.
A so-called two-piece can in which a lid is wound around the upper end of the bottomed can body is widely used.

In these canned cans, many efforts have been made to make the material thickness as thin as possible for the purpose of reducing the material cost of the can and reducing the weight of the can itself. However, if the material thickness is reduced,
The mechanical strength of the can body naturally lowers, and in particular, during the cooling process after the content filling and sterilization, or during the subsequent storage or transportation, the can body is significantly deformed (deformed) due to the reduced pressure inside. Further, in the case of a canned product, collision between cans may be unavoidable during handling or transportation, but the collision may cause deformation of the can body.

When such a deformation occurs in the can body of a can for canning, not only the appearance of the product is deteriorated and the commercial value is impaired, but also pinholes, cracks, peeling, etc. are formed in the inner and outer protective coating layers of the metal plate. There is a possibility that coating defects may occur, causing problems such as corrosion, metal elution, or leakage due to pitting corrosion. Conventionally, as a means for reinforcing the can body member, it is known to form a bead in the circumferential direction and a bead in the can height direction (can axis direction) on the can body member.

[0005]

When the bead is formed on the can body member, in order to prevent the above-mentioned reduced pressure deformation and the like,
Although quite effective, even if a circumferential bead is provided on the front surface of the can body member, the increase in the deformation load due to external pressure (increase in external pressure deformation strength) is about twice as high as that of a similar can without a bead. However, even when the material is significantly thinned, the purpose of completely preventing the reduced-pressure deformation is still unsatisfactory.

In addition, when a bead is formed on the can body, the printed outer surface becomes uneven, and the aesthetics and commercial value of the can are lost, and a coating defect appears on the inner surface of the can. There is a drawback that the exposure (ERV value) becomes high. For this reason, beaded can bodies currently in practical use are provided with circumferential beads only in a very limited portion of the can body.

Therefore, it is an object of the present invention to introduce a new reinforcing structure in place of the conventional bead, so that external pressure (or internal pressure reduction) can be achieved.
The object of the present invention is to provide a can for can which has a significantly improved deformation strength, good appearance characteristics, and in the case of an internally coated can, in which metal exposure on the inner surface of the can is suppressed to a relatively small range. Another object of the present invention is that the outer surface of the can has a peculiar three-dimensional appearance and aesthetics based on a polyhedron, the can body can be easily gripped when drinking the contents of the can, and also has resistance to dents. The purpose is to provide cans for canning.

[0008]

According to the present invention, a circumferential polyhedron wall is formed on at least a part of a can body, and the polyhedron wall has structural unit surfaces, and boundary ridge lines and boundary ridge lines at which the structural unit surfaces are in contact with each other. There is a crossing part where the parts intersect each other, and the boundary ridge line and the crossing part are convex to the outside of the can relative to the constitutional unit surface, and the adjacent can axial direction arrays of the constitutional unit surface form a phase difference. The number of the constituent unit surfaces in the circumferential direction is n, the inner radius of the can body is r (mm), the thickness of the can body is t (mm), and the can body material is When the elastic modulus is E (kg / mm ^ 2), the yield stress of the can body material is σy (kg / mm ^ 2), and the ratio of the height of the portion other than the polyhedral wall per can height is α, the above configuration The number of unit surfaces (n), the thickness of the can body (t), and the height ratio (α) of the portion other than the polyhedron wall per can height can be calculated using the equations "equation 1" and "equation 2".
A can for cans having excellent deformation resistance against external pressure, characterized by being set within a range that satisfies the above condition.

In the canned can of the present invention, when the maximum length of the structural unit surface in the axial direction of the can is L and the maximum width of the structural unit surface in the circumferential direction of the can is w, L and w are expressed by the formula 3 "is satisfied, and the distance between the diagonal line between the crossing points that gives the maximum width in the circumferential direction of the structural unit surface and the diagonal line between the crossing points that gives the maximum axial length of the structural unit surface (both diagonal lines are orthogonal to each other. D1) and the distance between the position where the measurement line of the distance d0 intersects the structural unit surface and the diagonal line between crossing points that gives the maximum axial length of the structural unit surface is d1. It is preferable that the value of d0 is within the range satisfying the following expression "Equation 4". Further, the boundary ridge line portion where the constituent unit surfaces contact each other is a single-point bending portion or a multiple-point bending portion having a gentle R (curvature radius), and R is relative to the plate thickness t and the can body radius r. It is preferable that the value is within the range that satisfies the expression "Equation 5".

[0010]

In the can for cans of the present invention, the circumferential polyhedron wall is formed on at least a part of the can body, and the polyhedron wall has the structural unit surfaces, the boundary ridge lines where the structural unit surfaces are in contact with each other, and the intersections where the boundary ridge lines intersect each other. The boundary ridgeline and the intersecting portion are relatively convex to the outside of the can as compared to the constitutional unit surface, and adjacent can axial direction arrangements of the constitutional unit surface are arranged with a phase difference. However, the number of structural unit faces in the circumferential direction is n (pieces), the inner radius of the can body is r (mm), the wall thickness of the can body is t (mm), and the elastic modulus of the material of the can body is E (kg / mm ^). 2), where the yield stress of the can body material is σy (kg / mm ^ 2) and the ratio of the height of the portion other than the polyhedron wall per can height is α, the above n, t, and α are expressed by the formula It is a salient feature to set so as to satisfy "" and "Equation 2".

FIG. 20 shows the inside radius of the can body r (mm), the elastic modulus of the can body material E (kg / mm ^ 2) and the yield stress σ of the can body material.
For a can body with a constant y (kg / mm ^ 2) (see the examples described later for details), the wall thickness t is changed in the range of 0.08 to 0.12 mm, and the left side and the right side of the formula "Equation 1" are equal. If (the right side can be regarded as a constant), that is, the formula

[0012]

[Equation 6] Is plotted with α as the horizontal axis and n as the vertical axis. The above formula "Equation 6" is an empirical formula derived from a number of experiments and its analysis, and may be a region below the formula "Equation 6" (that is, a region satisfying the equation "Equation 1"). For example, it has been found that it can withstand severe retort sterilization.

FIG. 18 is a plot of n and α for Examples 1 to 5 and Comparative Examples 1 to 3, and excellent retort resistance is obtained in a region satisfying the expression "Equation 1". It can be seen that a satisfactory retort resistance cannot be obtained in a region outside the formula "Equation 1". "FIG. 19" is for Examples 6 to 7 and Comparative Examples 4 to 8, and "FIG. 20" is
Regarding Examples 8 to 10 and Comparative Examples 9 to 12, “FIG. 21” is a plot of n and α for Examples 11 to 12 and Comparative Examples 13 to 14, respectively. In the area that satisfies the formula "Equation 1",
It is also clear that excellent retort resistance can be obtained, and satisfactory retort resistance cannot be obtained in a region outside the formula "Formula 1".

The above results show the following. That is, (i) it is effective to improve the retort resistance by reducing the height ratio α of the portion other than the polyhedron wall per can height, (ii) the number n of the constituent unit faces in the circumferential direction is reduced. It is effective to improve the retort resistance. (Iii) The smaller the thickness, the greater the effect of reducing the values of α and n. When α is large and n is small, the retort resistance region is narrowed. It is considered that when n is small, L is restricted and L / w becomes small, so that the resistance against external pressure becomes weak.

In the present invention, in relation to the inner radius r of the can body,
It is also important to determine the wall thickness t so as to satisfy the above-mentioned expression "Equation 2". That is, an unexpected fact was found that the corrosion resistance of the surface of the can body is significantly improved by setting the thickness of the can body wall thickness t to satisfy the equation "Formula 2". The reason for this is
When forming a circumferential polyhedron wall on the can body surface, if the wall thickness is large, the amount of compressive deformation at the boundary ridges and intersections will be large, so peeling, cracks, pinholes, etc. will occur due to compression of the coating film. On the other hand, if the wall thickness t per the inner radius r of the can is determined so as to satisfy the expression "Equation 2", it becomes possible to suppress the amount of compressive deformation at the boundary ridge line portion or the intersection portion within a small range. Therefore, it is possible to effectively prevent peeling, cracks, pinholes, and the like due to compression of the coating film. Further, by reducing the thickness of the can body, it is possible to save the material cost and to reduce the weight of the can.

In the present invention, it is desirable that the values of L and w satisfy the value of the above-mentioned "expression 3", from the viewpoint of the external pressure resistance, and L / w is outside the range of the expression "expression 3". If so, buckling deformation and the like are likely to occur.

Further, it is also preferable that d1 / d0 is in the range of the above-mentioned formula "4" from the viewpoint of corrosion resistance, and when d1 / d0 is outside the range of the above-mentioned formula "4", the can body is corroded. Will progress significantly.

Further, the radius of curvature R of the ridge portion is expressed by the above-mentioned equation "Equation 5".
It is also desirable to be in the range of from the viewpoint of the balance between corrosion resistance and pressure resistance, and if it is out of this range, the balance tends to be lost.

[0019]

Preferred Embodiment of the Invention

Basic Structure and Shape In FIG. 1 (a is a side view, b is a partial cross-sectional view) and FIG. 2 (top view) showing an example of a can of the present invention, this can is of both-end opening. It is composed of a can body 10 and top and bottom can lids 18, 18 wound on both ends. The can body 10 is formed with a polyhedral wall in a circumferential shape. The polyhedral wall has a structural unit surface 1, a boundary ridge line 2 where the structural unit surfaces are in contact with each other, and a crossing portion 3 where the boundary ridge lines intersect with each other. The boundary ridgeline 2 and the intersecting portion 3 are relatively convex to the outside of the can as compared with the structural unit surface. In this polyhedron wall, adjacent can axis direction arrays of the constituent unit surfaces 1 are arrayed with a phase difference.

In this specific example, the constitutional unit surface 1 is composed of a quadrilateral (diamond) abcd, and adjacent can axial direction arrangements of the constitutional unit surface 1 are arranged with a phase difference of exactly 1/2. ing. FIG. 3 shows an example of the quadrilateral unit surface 1 of the polyhedral wall surface used in the can body of FIG. 1, and the rhombus abcd is the constituent unit surface 1. Each side ab, bc, cd, da in the rhombus is a side corresponding to the boundary ridgeline 2 formed on the side surface of the can, and the outwardly convex vertices a, b, c, d correspond to the intersection 3.

The upper apex a and the lower apex c are located on the circumferential surface having the same diameter, and the left apex b and the right apex d are located on the circumferential surface having the same diameter. When the array has a phase difference of ½, all the vertices are located on the circumferential surface of the same diameter, and as shown in “FIG. 2”, the radii inside the can body corresponding to these vertices are The maximum radius is r. On the other hand, each ridge line ab,
Although bc, cd, and da are projected most radially outward at the ends,
The distance from the center axis of the can, that is, the diameter, decreases as it goes to the middle. When the diameter s of the midpoint of the diagonal line bd in the circumferential direction is taken, this diameter s is smaller than r, and in the case of "FIG. 2", the minimum inner radius is given. When the unit surface on the can body is projected in the axial direction, the apex ac overlaps, but the diagonal line ac in the axial direction ac
Is located radially outward of the diagonal line bd without overlapping with the diagonal line bd in the circumferential direction, it will be understood that the quadrangle abcd is a curved or bent surface.

In FIG. 3, the rhombus dimension as the structural unit surface is such that when the length of the circumferential diagonal line bd is w and the height of the axial diagonal line ac is L, w and L are respectively the structural unit surface. Maximum width in the circumferential direction and maximum length in the axial direction. It is already clear from the above description that the length ac (height L) of the axial diagonal line is different from the actual length in the ac cross section on the constituent unit surface, but the length of the circumferential diagonal line bd (w ) And the actual length of the bd cross section on the structural unit surface may differ from each other. For example, in "FIG. 2", the diagonal line bd in the circumferential direction and the bd cross section on the actual structural unit surface are the same, and their lengths are the same, but "FIG. 1"
In the case of (b) showing the AC cross section of (a), the midpoint e of the side ac in this cross section is located radially outward from the position of the diagonal line bd in the circumferential direction, and thus the side bed is in the circumferential direction. It is larger than the length (w) of the diagonal line bd. The distance between the diagonal line between the crossing points that gives the maximum width in the circumferential direction of the structural unit surface and the diagonal line between the crossing points that gives the maximum axial length of the structural unit surface (the length of the line connecting the diagonal lines at right angles) is d0 and the above. Distance d0
Assuming that the distance between the position where the measuring line intersects the structural unit surface and the diagonal line between the crossing points that gives the maximum axial length of the structural unit surface is d1, d1 is smaller than d0 in the case of (b) of "Fig. 1". ,
Conversely, d1 may be greater than or equal to d0.

In a can body having a polyhedral wall formed by combining such unit-constituting faces as described above, (b) of FIG. 1 is used.
As shown in FIG. 5, the structural unit surface appears as a curved or U-V shaped depression. With such a unit surface configuration,
The / 2 phase arrangement imparts deformation resistance to the can body, and since molding can be performed while keeping the surface area of the can body before forming the polyhedral wall and the can surface area after forming the polyhedral wall substantially equal,
Excellent corrosion resistance is maintained without causing damage to the coating film, less stress remains after processing, and effective for retort sterilization and subsequent reduction of coating film adhesion and seam adhesive strength over time. Will be resolved.

The constitutional unit surface of the polyhedral wall is constituted by a quadrangle,
It is the best to prevent the deformation of the can due to the external pressure by introducing the structural unit surface into the side wall of the can alternately and firmly. Further, in the case where the diamond-shaped unit surface is smoothly curved around the line bd and the curved portion is arranged so as to be convex inward, the strength of the can is large and the corrosion resistance is particularly excellent.

In the present invention, the number of corners n of the polyhedral wall in the circumferential cross section, the can barrel wall thickness t, and the ratio α of the height of the portion other than the polyhedral wall per can height to the inner radius r of the can barrel, the can barrel Based on the relationship between the elastic modulus E of the material and the yield stress σy of the can body material, the equations “Equation 1” and “Equation 2” are set so as to be satisfied. The number n of constituent unit surfaces existing around the circumference of the can body is at least 3 or more, and preferably 4 or more. If n is less than 3, it is not possible to form a sufficient multi-faceted wall surface on the can body, and the degree of plate bending due to bending becomes severe, so that the corrosion resistance of the coating film is significantly reduced and the appearance is also deteriorated. . On the other hand, the upper limit is set so as to satisfy the equations "Equation 1" and "Equation 2". α
The value of is given by the formula, where H0 is the can height and H1 is the height of the polyhedral wall.

[0026]

## EQU7 ## This is represented by .alpha. = 1-H1 / H0. In FIG. 1, α is not 0 but takes a value close to 0, but its upper limit value is generally 0.9 or less, particularly 0.8 or less, and in relation to n and t, the expression “number 1) and “Equation 2” are satisfied. "Fig. 4" shows the can body 1.
The polyhedron wall portion 10a is provided only in the central portion of 0, and the unprocessed portion, that is, the cylindrical portion 10b is left in the upper and lower portions.
The can body wall thickness t is firstly determined so as to satisfy the expression "Equation 2" in relation to the maximum inner radius r, but even when t is sufficiently small, the expression "Equation 1" is satisfied. So that n and α
It is the basic idea of the present invention that sufficient retort resistance can be obtained by selecting.

The relationship between w and L is important for increasing the strength of the can of the present invention, and also has a great influence on the appearance of the can. That is, it is desirable that the relationship between w and L satisfies the formula "Equation 3", and this is not limited to the quadrangular structural unit surface, and is the same for the hexagonal structural unit surface. When the L / w exceeds the above range, the outer appearance of the can is not so problematic, but the original can outer pressure resistance of the can is lowered. On the other hand, when L / w is smaller than the above range, the can body itself tends to be deformed by axial compression although the outer can pressure resistance is good. It is understood that this is not a problem if general pipe material is used, but it is an important problem for the can body. Further, when L / w is in such a range or less, the appearance is deteriorated, and the appearance of the printed image on the can surface may be deteriorated.

When the depth amount d1 of the structural unit surface is smaller than the range of the above relation, sufficient action against external pressure cannot be obtained. On the other hand, if the depth amount d1 is larger than the above range, buckling of the can from the axial direction is likely to occur, and the difference in surface area between before and after the formation of the multi-sided wall becomes large. The adhesive strength and the adhesive strength at the joint are lowered, which is not preferable. Further, the appearance on printing is also deteriorated.

Further, d0 is closely related to the maximum width w of the structural unit surface, and w is related to the above-mentioned maximum length L in the axial direction. Therefore, the depth amount d has a close relationship with these w and L, and the permissible range also changes depending on their length. For example, in the quadrangular unit plane,

[0030]

## EQU8 ## d0 = rs, and

[0031]

S = rcos (π / n),

[0032]

From w = 2rsin (π / n),

[0033]

[Equation 11] d0 = 1/2 ・ w (sin (π / n)) ^-1・ (1-cos (π / n)), and d0 is the maximum width w and the number of constituent unit faces existing in the circumferential direction. It is understood that it is determined by n, and the depth amount d1
The larger the value of w, the larger the range that can be taken, and the larger the value of n, the smaller the range that can be taken.

The above-mentioned effects of the structural unit surface can be seen also in the case of being formed in the central portion of the can body as shown in FIG. The action and effect tend to be greater than those formed. Further, in the can body of "FIG. 4", it is preferable to form the can body at a height of at least 10%, especially at least 20% of the height of the can body.

Deformation of Structure and Shape Further proceeding from the state in which the constitutional unit surface is a quadrilateral, a complete fold is formed in the central portion of the quadrilateral which is the constitutional unit surface in FIG. And “FIG. 6”. Also in this case, the repeating structural unit surface is a quadrangle (diamond), but each structural unit surface 1 is one in which two isosceles triangles ABC and BCD are connected at their bases BC and two Excluding the triangle orientation,
It can be said that the isosceles triangle ABC is the minimum surface constitutional unit (basic surface constitutional unit). The AD cross section of the structural unit surface 1 has a V shape as shown in (b) of FIG. 5, and the side of the BC cross section of the structural unit surface 1 coincides with the diagonal line BC. That is, the depth amount d1 is equal to d0.

That is, in the arrangement of this specific example, the apex 3 is at the most projecting position in the radially outer direction of the can body, the bottom side 4 is at the recessed position in the radially inner direction of the can body, and the opposite sides 2 and 2 are The polyhedron in the middle position between them can be said to be a polyhedral wall having opposite sides 2 and 2 as ridges and bottom 4 as a valley.

Further, FIG. 7 shows another modification of the structural unit surface 1. The constituent unit surface 1 is a quadrangle, and the boundary ridge line 2 where the constituent unit surfaces contact each other and the crossing portion 3 where the boundary ridge lines intersect each other.
And the boundary ridge line 2 and the intersecting portion 3 are convex to the outer side of the can relative to the constitutional unit surface, but are more common than other ones, but further than the circumferential diagonal line bc. It has a surface center portion f (the most recessed portion 6) that is recessed inward, and has a circumferential polygonal line or curved line 4 and an axial polygonal line or curved line 5 that passes through this surface central portion f. It differs from the example. In this constitutional unit surface, the depth amount d1 of the constitutional unit surface is d
It is larger than 0, and can be up to about 2d0 by ignoring some molding error. This type of can has a good geometrical appearance and corrosion resistance, and excellent grip.

Further, in the present invention, the constitutional unit surface is not limited to a quadrangle, and it is needless to say that it may be another polygon, for example, a hexagon. FIG. 8 shows an example in which the structural unit surface is a hexagon. Also in this case, the hexagonal structural unit surface 1 has a boundary ridge line 2 where the structural unit surfaces are in contact with each other and an intersecting portion 3 where the boundary ridge lines intersect with each other, and the boundary ridge line 2 and the intersecting portion 3 are compared with the structural unit surface. A point that is relatively convex outward in the radial direction and a point that the axial arrangement of the constituent unit surfaces that are adjacent to each other in the circumferential direction are arranged with a constant phase difference (in this example, approximately 1/2 phase difference) So it has something in common with others. It can be understood from the both sides of "Fig. 8" that the component unit surface is recessed toward the inside of the can body.

Further, as shown in FIGS. 9 to 10, the shape of each structural unit surface 1 is a polygon with rounded corners or a circle or an ellipse, and the boundary ridge line portion 2 and the boundary ridge lines intersect each other. It is possible to form the apex 3 so as to have a constant radius of curvature R without forming a sharp corner. R can be related based on the plate thickness t and the radius D of the can body,
R is the formula

[0040]

[Equation 12] It is desirable to satisfy t ≦ R ≦ (2/3) D. If a curve is formed along the boundary ridgeline in this range, the adhesion of the coating film applied to the surface of the processing can is sufficiently maintained, and the stress at the boundary is slow to be formed so that the film is not damaged. Further, such bending near the boundary ridge may be one curve, that is, the maximum position of the bend R near the ridge may be only one.
Further, although there is no problem even if there are a plurality of constant bends R distributed at a plurality of locations, it is desirable that the R formed near the ridgeline be within the above range.

As shown in FIG. 10, even when the structural unit surface 1 is a quadrangle, the curved portion R is formed at the intersection 3 as well.
It goes without saying that can be formed.

Furthermore, the present invention can be applied to so-called bead cans. 22. FIG. 22 shows a can with a circumferential bead 20 provided at a small distance from the winding portion 18, but as shown in FIG. 23, a polyhedral wall consisting of the structural unit surface 1 between the upper and lower circumferential beads. It is also possible to engrave.

Manufacturing Method According to the present invention, a metal plate or the like is formed into a tubular shape, and opposing end line portions are joined by means such as welding, adhesion, or soldering to form a side seamed can barrel, and the can barrel is formed. A so-called three-piece can, which is formed by winding both ends of the can with a top and bottom lid, or a metal plate is drawn into a bottomed can body or deep drawn or further ironed, and the lid is wound around the upper end of the bottomed can body. It can be applied to so-called two-piece cans.

The canned can of the present invention is manufactured by forming the polyhedron by pressing the can body before winding the lid with the inner mold and the outer mold. The inner mold used has projections corresponding to the vertices and edges of the polyhedron on the surface, while the outer mold used has projections corresponding to the valleys of the polyhedron on the surface. The polyhedron is formed by engaging the mold and the outer mold with each other through the can body.

FIGS. 12 to 16 are explanatory views showing a method of engraving a polyhedron on a can body whose constituent unit surface is a quadrangle, but the principle is applicable even when the constituent unit surface is other than a quadrangle. Is no different from this. The can body 10 includes an inner mold 11 and an outer mold 12.
It is rotated while being sandwiched between. On the surface of the inner mold 11, projections 13 corresponding to the vertices of a polyhedron and a rhombic surface 14 refracted or curved with respect to the can peripheral surface ("FIG. 12" shows only a half surface).
Further, in FIG. 12, the concave portion 15 corresponding to the bent or curved portion (valley portion or common base of the facing isosceles triangle) of the polyhedral wall is shown as a line of the central cut surface. . On the surface of the outer mold 12, a concave portion 16 corresponding to the inner protrusion 13 is formed, and a protruding portion 17 corresponding to the inner concave portion 15 is formed, and the protruding portion 17 is a recess of the polyhedral wall. Further, a refraction or curved portion (a valley portion or a common base of opposing isosceles triangles) is formed. "Figure 14" and "Figure 15"
[FIG. 8] is an enlarged cross-sectional view showing this protrusion 17 of the outer die, taken along the line V-V. In FIG. 14, the curved protrusion 17
Further, in FIG. 15, it will be understood that the protrusions 17 bent in a V shape are respectively engaged with the can body 10 to form the concave unit component surface 1. Further, in FIGS. 14 and 15, if the outer mold 12 is made of an elastic material, for example, a rubber-like material, the constituent unit surface can be easily molded without damaging the coating film or the like. be able to.

The inner mold 11 and the outer mold 12 are connected to the can body 10.
The polyhedrons are engraved on the can body by engaging them through and rotating them at a synchronized speed.
Incidentally, when a part of the meshes is misaligned during the rotation, the inner or outer rotating shaft may be slightly moved up and down.

In the specific examples shown in FIGS. 12 and 13, the inner mold 11 and the outer mold 12 have a smaller diameter than the can body 10, but the inner mold 11 and the outer mold 12 have the same surface. The number of basic surface constitutional units arranged in the circumferential direction is set to be one or plural smaller than that in the periphery of the can body, but there is no problem in forming a polyhedron in practical use. By separating the inner mold 11 and the outer mold 12, the polyhedral carved can barrel can be easily taken out.

Alternatively, as shown in FIG. 16, an inner mold 11a having a partial outer peripheral surface having a peripheral length shorter than one half of the can body and an outer mold 12a having the same inner peripheral surface are used. ,
It is also possible to engrave a polyhedron by making thickness marking a plurality of times on the entire circumference of the can body with the inner mold 11a and the outer mold 12a while the can body is positioned. Also in this case, either one or both can be used as the elastic material.

These engraving treatments can be performed on the entire surface of the can body or in the central portion thereof, and also at a plurality of locations. If neck-in processing is applied to the top and bottom of the can body,
It is advisable to engrave the polyhedron on the portion excluding the neck-in processed portion.

Although not shown, when the constituent unit surface is a hexagon, a polygon with rounded corners, or another shape, as shown in FIGS. It is possible to use different molds, and by using those having a predetermined radius of curvature R for the troughs and tops of each mold, "FIG. 8" and "FIG. 10" It is possible to manufacture one having a gentle curved portion at the boundary as shown in FIG.

Further, in the present invention, the structural unit surface may be provided on the can body by a bulge method. The bulge method is
This is a method of increasing the diameter of the can body by inserting a member having an expandable / contractible structure, for example, a synthetic rubber having a slip-like structure into the can body and expanding it. In such a system, the outer die of the structural unit surface is arranged around the can body, the can body is inflated by the expansion / contraction member, and the can body is pressure-bonded to the outer die so that the diameter of the can body is increased and processed. The thickness of the can body can be reduced, and at the same time, the excellent structural unit surface described above can be formed on the can body. In forming such a structural unit surface, the neck-in processing of both end portions of the can body can be performed in advance, and the reduction in thickness for the purpose of the present invention can be facilitated. Furthermore,
It is possible to form the constituent unit surfaces on the can body in an accurate arrangement.

Metal Material In the present invention, various surface-treated steel plates and light metal plates such as aluminum are used as the metal plate. As the surface-treated steel sheet, one or more surface treatments such as cold-rolled steel sheet or secondary cold-rolled after annealing, zinc plating, tin plating, nickel plating, electrolytic chromic acid treatment, chromic acid treatment, etc. What is done can be used. An example of a suitable surface-treated steel sheet is an electrolytic chromic acid-treated steel sheet, particularly 10 to 2
A metal chrome layer of 00 mg / m ^ 2 and a chromium oxide layer of 1 to 50 mg / m ^ 2 (metal chrome conversion) are provided,
This product has an excellent combination of coating film adhesion and corrosion resistance. Another example of surface-treated steel sheet is 0.5 to 11.2g / m ^ 2
It is a hard tin plate having the tin plating amount of. It is desirable that this tin plate has been treated with chromic acid or chromic acid / phosphoric acid of 0.5 to 100 mg / m ^ 2 in terms of metal chromium.

As the light metal plate, an aluminum alloy plate is used in addition to the so-called pure aluminum plate. Aluminum alloy sheets with excellent corrosion resistance and workability are Mn: 0.2 to
The composition is 1.5% by weight, Mg: 0.8 to 5% by weight, Zn: 0.25 to 0.3% by weight, Cu: 0.15 to 0.25% by weight, and the balance is Al. These light metal plates are also converted into metal chromium,
Chromic acid treatment or chromic acid / phosphoric acid treatment is preferably performed so that the amount of chromium is 3 to 300 mg / m ^ 2.

The thickness t of the metal in the body of the can is a thickness that satisfies the above-mentioned equations "equation 1" and "equation 2". Even when the thickness is set to be small, the number n and α of the constituent unit faces are small. It is one of the advantages of the present invention that excellent anti-retort property can be achieved by selecting the above range. The specific thickness varies depending on the maximum radius of the can body and the type of metal, but in the case of surface-treated steel sheet, 0.08 to 0.24 mm, particularly 0.12 to 0.17 mm thin steel sheet, and in the case of aluminum sheet, 0.1 to 0.4
It is possible to obtain a can having a high external pressure strength by selecting a thin aluminum plate having a predetermined thickness from a thin aluminum plate having a thickness of 0.1 mm, particularly 0.14 to 0.3 mm.

Protective coating In the present invention, the protective coating of resin is applied to the metal plate at any stage prior to engraving the polyhedron, and the protective coating layer is not damaged even when this is subjected to the polyhedral engraving operation. This is a remarkable advantage. The formation of the protective coating, by providing a protective coating,
Alternatively, it is performed by laminating a thermoplastic resin film.

As the protective coating, any protective coating composed of thermosetting and thermoplastic resins: modified epoxy coating such as phenol-epoxy coating, amino-epoxy coating, etc .: vinyl chloride-vinyl acetate copolymer, vinyl chloride. -Partially saponified vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, epoxy modified-,
Epoxyamino-modified or epoxyphenol-modified vinyl such as vinyl paint or modified vinyl paint: Acrylic resin-based paint: Styrene-butadiene-based copolymer or other synthetic rubber-based paint, etc., alone or in combination of two or more. It

These paints are used in the form of an organic solvent solution such as enamel or lacquer, or in the form of an aqueous dispersion or aqueous solution, such as roller coating, spray coating, dip coating, electrostatic coating, and electrophoretic coating. Shaped on metal material. Of course, when the resin paint is thermosetting, the paint is baked if necessary. From the viewpoint of corrosion resistance and workability, the protective coating film preferably has a thickness (dry state) of generally 2 to 30 μm, particularly 3 to 20 μm. Further, in order to improve the processability, various lubricants can be contained in the coating film.

As the thermoplastic resin film used for lamination, polyethylene, polypropylene, ethylene-
Propylene copolymer, ethylene-vinyl acetate copolymer,
Olefin-based resin films such as ethylene-acrylic ester copolymers and ionomers: Polyester films such as polyethylene terephthalate, polybutylene terephthalate, ethylene terephthalate / isophthalate copolymers: nylon 6, nylon 6,6, nylon 11, nylon 12, etc. Polyamide film: polyvinyl chloride film: polyvinylidene chloride film. These films may be unstretched or biaxially stretched. Its thickness is generally 3 to 50 μ
m, particularly preferably in the range of 5 to 40 μm.
Lamination of the film on the metal plate is carried out by a heat fusion method, dry lamination, extrusion coating method or the like. When the adhesiveness (heat fusion property) between the film and the metal plate is poor, for example, a urethane type is used. An adhesive, an epoxy adhesive, an acid-modified olefin resin adhesive, a copolyamide adhesive, or a copolyester adhesive can be interposed.

In the case of a three-piece can, the above resin-coated plate is used, and this is molded into a tubular shape, and the end line portion not covered with the resin is welded by an electric resistance welding method known per se. Coat to make a can body. Further, the end line portion can be heat-bonded with a nylon adhesive to form a can body, and when a metal tin layer is present on the end line portion, they can be joined by soldering.

Further, in the case of a two-piece can, the coated metal plate is subjected to drawing or deep drawing to produce a bottomed can barrel having a total drawing ratio in the range of 1.1 to 4.0, particularly 1.5 to 3.0. A polyhedron is engraved on the bottomed can body. Of course,
At the time of deep drawing or subsequent thereto, thinning processing by bending and stretching and ironing processing can also be performed. When performing ironing, a resin coating may be provided in advance, or a resin coating may be provided on the can body after the ironing.

[0061]

[Example] "Fig. 17" shows that the components of the can are made of TFS material (E = 210).
00Kg / mm ^ 2, σy = 60Kg / mm ^ 2), radius 26.2mm, can height 120m
When m and the plate thickness t (0.08 to 0.12) mm, the boundary line between n and α that satisfies the empirical formula “Equation 1” is shown. In FIG. 17, the can having the circumferential polyhedron wall formed in the region where n and α were smaller than the curve showed good results without deformation of the can barrel when subjected to external pressure during retort sterilization. This will be specifically described below.

Example 1 TF having a plate thickness of 0.12 mm, which is obtained by applying an epoxy-based paint to a thickness of 5 μm.
The minimum constitutional unit surface shown in "Fig. 3" is placed at the center of the can height on the can body of an adhesive can with a radius of 26.2 mm and a can height of 120 mm, which is made by stacking and joining S materials with a polyamide adhesive. , Including 9 in the circumferential direction, and 60 mm with 1/2 phase difference in the can axis direction.
The outer surface body was formed by using a pressing tool so as to have a width and an L / W of 0.98 and a depth ratio d1 / d0 of 0.95. After vacuum-wrapping the beef stew in an empty can with the lid wrapped around the can body to a vacuum degree of 25 cmHg, perform retort sterilization treatment at 125 ° C for 60 minutes, and apply a pressure of 1.3 Kg / cm ^ 2. After cooling while applying, the deformation of the body of the can was visually observed to evaluate the resistance. As a result, there was almost no deformation and it had resistance to retort sterilization.

Examples 2, 3, 4, 5 In Examples 2, 3, 4, 5, n and α satisfying the empirical formula "Equation 1" are values shown in "Table 1". A can body having a peripheral polyhedron wall was formed in the same manner as in Example 1 except that the above procedure was performed. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The result is "Table 1"
Shown in. In FIG. 18, the boundary line of the empirical formula “Equation 1” and the positions of (n, α) in Examples 1 to 5 are indicated by circles.

Comparative Examples 1, 2, and 3 Comparative Examples 1, 2, and 3 are different from each other except that n and α which do not satisfy the empirical formula "Equation 1" are set to the values shown in "Table 2". A can body having a peripheral polyhedron wall was formed in the same manner as in Example 1. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 1". In FIG. 18, the boundaries of the empirical formula “Equation 1” and the positions of (n, α) in Comparative Examples 1 to 3 are indicated by Δ numbers.

Examples 6 and 7 In Examples 6 and 7, except that n and α and plate thickness t satisfying the empirical formula "Equation 1" are set to the values shown in "Table 2", respectively. In the same manner as in Example 1, a can body having a circumferential polyhedron wall was formed. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 2". In FIG. 19, the boundary line of the empirical formula “Equation 1” and the positions of (n, α) in Examples 6 and 7 are indicated by circles.

Comparative Examples 4, 5, 6, 7, and 8 Comparative Examples 4, 5, 6, 7, and 8 show the values of n, α, and plate thickness t that do not satisfy the empirical formula "Equation 1", respectively. A can body having a circumferential polyhedron wall was formed in the same manner as in Example 1 except that the values shown in "2" were set. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 2". Empirical formula "Equation 1" in "Fig. 19"
Boundary line of and the position of (n, α) in Comparative Examples 4 to 8 are indicated by Δ numbers.

Examples 8, 9 and 10 In Examples 8, 9 and 10, the can radius was 32.7 mm and the plate thickness t was 0.1.
A can body having a peripheral polyhedron wall was prepared in the same manner as in Example 1 except that the thickness was 4 mm and the values of n and α satisfying the empirical formula "Equation 1" were respectively set to the values shown in "Table 1". Molded.
Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 1". "Figure 20"
In addition, the boundary line of the empirical formula “Equation 1” and (n,
The position of α) is indicated by a circle.

Comparative Examples 9, 10, 11, 12 Comparative Examples 9, 10, 11, 12 have a can radius of 32.7 mm and n and α that do not satisfy the empirical formula "Equation 1" are shown in Table 2 respectively. Example 1 except that the values shown in FIG.
A can body having a peripheral polyhedron wall was formed in the same manner as in. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 2". In FIG. 20, the boundaries of the empirical formula “Equation 1” and the positions of (n, α) in Comparative Examples 9 to 12 are indicated by Δ numbers.

Examples 11 and 12 In Examples 11 and 12, the values of n, α, t, and E and σy of the can body which satisfy the empirical formula "Equation 1" are shown in "Table 1", respectively. A can body having a peripheral polyhedron wall was formed in the same manner as in Example 1 except that the above was adopted. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 1". In FIG. 21, the boundary line of the empirical formula “Equation 1” and the positions of (n, α) in Examples 11 and 12 are indicated by circles.

Comparative Examples 13, 14 and 15 In Comparative Examples 13, 14 and 15, n, α, t and E, σy of the can body material which do not satisfy the empirical formula "Equation 1" are shown in Table 2, respectively. Example 1 except that the values shown in FIG.
A can body having a peripheral polyhedron wall was formed in the same manner as in. Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 2". In FIG. 21, the boundary line of the empirical formula “Equation 1” and (n, α) of Comparative Examples 13 to 14 are shown.
The position of is indicated by a triangle.

Example 13 Example 13 is the same as that of Example 1 except that a small number of beads and a peripheral polyhedral wall were formed on the can body as shown in FIG. 23.
Using this can body, the retort sterilization resistance was evaluated in the same manner as in Example 1. The results are shown in "Table 1".

Comparative Example 16 In Comparative Example 16, the same can barrel as in Example 1 was not formed with the peripheral polyhedron wall, and the retort sterilization resistance was evaluated in the same manner as in Example 1 using this can barrel. did. The results are shown in "Table 2".

Comparative Example 17 In Comparative Example 17, only a small number of beads were formed on a can body similar to that of Example 1 as shown in FIG. 22. The retort sterilization resistance was evaluated. The results are shown in "Table 2".

[0074]

[Table 1]

[0075]

[Table 2]

From Examples 1 to 7 and Comparative Examples 1 to 8, the number n of the minimum constitutional unit surfaces connected in the circumferential direction and the can height of the can body width which does not have the circumferential polyhedron wall in the axial direction are compared. Proportion α
Is the radius r of the can body, the elastic modulus E of the plate material and the yield stress σ
If the region was set to satisfy the condition of the empirical formula "Equation 1" from y and plate thickness t, good results were obtained with almost no deformation in the retort sterilization.

From Examples 8 to 10 and Comparative Examples 9 to 12, even if the can diameter r is different, it is effective if the region is set to (n, α) so as to satisfy the condition of "Equation 1". Retort sterilization resistance is obtained.

Examples 11 and 12 and Comparative Examples 13 to 15
Therefore, the elastic modulus E and the yield stress σy of the aluminum plate etc.
Also satisfies the condition of "Equation 1" (n,
If it is set in the area of α), effective retort sterilization resistance can be obtained.

Comparative Example 16 has the same constitution as the can body in Examples 1 to 5, but the peripheral polyhedron wall is not formed, and the retort sterilization resistance is not satisfied.

In Comparative Example 17, a small number of beads were formed in order to improve the external pressure resistance, but with the same can barrel structure as in Comparative Example 16, no effective result for retort sterilization resistance was obtained.

In Example 13, a peripheral polyhedral wall was formed in addition to the small number of beads of Comparative Example 17, and the result satisfying the retort sterilization resistance was obtained.

[0082]

According to the present invention, at least a part of the can body is formed with a circumferential polyhedron wall composed of constituent unit surfaces, boundary ridges where the constituent unit surfaces are in contact with each other, and intersections where the boundary ridges intersect. Then, the boundary ridge line and the intersecting portion are projected relatively to the outside of the can as compared with the constituent unit surface, and the can axial direction arrays adjacent to each other in the circumferential direction of the constituent unit surface are arranged with a phase difference,
The number of structural unit surfaces in the circumferential direction is n (pieces), and the inner radius of the can body is r (m
m), the thickness of the can body is t (mm), the elastic modulus of the can body material is E (kg / mm ^)
2), assuming that the yield stress of the can body material is σy (kg / mm ^ 2) and the height ratio of the portion other than the polyhedron wall per can height is α, the above n, t, and α are expressed by “Equation 1”. Also, by setting so as to satisfy "Equation 2", it becomes possible to remarkably improve the retort resistance while significantly reducing the wall thickness of the can body. Furthermore, it is possible to prevent residual stress from remaining in the coating film after processing, and to prevent coating film defects from occurring, thereby improving the corrosion resistance of the can, and also reducing the manufacturing cost of the can and reducing the weight. It will be possible.

Also, some of the valleys in the circumferential direction have a smooth curve, which has good reproducibility when the design is applied to the appearance, improves the appearance, and leaves the contents in the container in a conventional cylindrical can. Few as well. Furthermore, in the above structure, an unexpected improvement in the deformation strength of the can body due to the external pressure is recognized, and it is possible to improve the deformation strength due to the external pressure in an order incomparable with the conventional beat reinforcing structure.

[Brief description of drawings]

FIG. 1 is a side view (a) and a vertical sectional view (b) of an example in which a quadrilateral of a can for can according to the present invention is used as a structural unit surface.

FIG. 2 is a horizontal sectional view of FIG.

FIG. 3 is a plan view (a) and a cross-sectional view (b) of an example of constituent unit surfaces formed on the side surface of the can for can of FIG.

FIG. 4 is a side view of a can for can in which the constituent unit surface shown in FIG. 3 is applied only to the central portion.

FIG. 5 is a plan view and a cross-sectional view of a structural unit surface of another mode formed on the side surface of a can for can, that is, an isosceles triangular unit surface.

FIG. 6 is a side view (a) and a vertical sectional view (b) of a can for can using the constituent unit surface of “FIG. 5”;

FIG. 7 is a side view of a can for can using another aspect of the structural unit surface.

FIG. 8 is a partial side view of a can for can according to the present invention having a hexagonal structural unit surface.

FIG. 9 is a partial side view showing two examples of a can for can using a hexagonal structural unit surface with roundness (R).

FIG. 10 is a partial side view showing two examples of a can for can using a hexagonal structural unit surface with roundness (R).

FIG. 11 is a partial side view of a can for can using a quadrilateral structural unit surface with roundness (R).

FIG. 12 is a cross-sectional view illustrating a method of engraving a polyhedron on a can body.

FIG. 13 is a perspective view illustrating a method of engraving a polyhedron on a can body.

FIG. 14 is a cross-sectional view showing a contact portion of the outer die with respect to the component unit surface.

FIG. 15 is a cross-sectional view showing a contact portion of the outer die with respect to the constituent unit surface.

FIG. 16 is a cross-sectional view illustrating another method for engraving a polyhedron on a can body.

FIG. 17 is a diagram in which boundary values are plotted by changing the wall thickness t of the can body and plotting the ratio α of the height of the polyhedral wall per can height and the number n of constituent unit surfaces in the circumferential direction.

FIG. 18 is a diagram in which n and α are plotted for Examples 1 to 5 and Comparative Examples 1 to 3.

FIG. 19 is a diagram in which n and α are plotted for Examples 6 to 7 and Comparative Examples 4 to 8.

FIG. 20 is a diagram in which n and α are plotted for Examples 8 to 10 and Comparative Examples 9 to 12.

FIG. 21 shows Examples 11 to 12 and Comparative Examples 13 to 14.
Plotting n and α for

FIG. 22 is a side view of a can body with a circumferential bead.

FIG. 23 is a side view of a can body having a polyhedral wall formed between circumferential beads.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Structural unit surface 2 Boundary ridgeline 3 Crossing part 4 Recessed concave part 10 Can body 11 Inner mold 12 External mold.

Front page continuation (72) Inventor Sumio Takeishi 179 Oguchinaka-cho, Kanagawa-ku, Yokohama, Kanagawa Prefecture (72) Inventor Seishi Kobayashi 52-8 Inuyama-cho, Sakae-ku, Yokohama-shi, Kanagawa Prefecture (72) Noritsugu Oshima Yokohama-shi, Kanagawa Green Kamoi, 5-26-5-305 (72) Inventor Kazuhiro Sawada 2-12-1, Minamimachi, Fuchu-shi, Tokyo

Claims (4)

[Claims] 1. A circumferential polyhedron wall is formed on at least a part of a can body, and the polyhedron wall has structural unit surfaces, a boundary ridge line where the structural unit surfaces are in contact with each other, and an intersection portion where the boundary ridge lines intersect each other. Border ridges and intersections are relatively convex to the outside of the can as compared to the structural unit surface, and adjacent can axial direction arrays on the structural unit surface are canned cans that are arranged with a phase difference. , The number of structural unit surfaces in the circumferential direction is n (pieces), the maximum inner radius of the can body is r (mm), the thickness of the can body is t (mm), and the elastic modulus of the material of the can body is E (kg / mm ^). 2), where the yield stress of the can body material is σy (kg / mm ^ 2) and the ratio of the height per can height to the portion other than the polyhedron wall is α, the above n, t and α are expressed by the following formulas: Number 1] And a can for canning excellent in deformation resistance against external pressure, which is set within a range satisfying t / r ≦ 0.0125. 2. The maximum length of the constituent unit surface in the can axis direction is L
And w is the maximum width of the structural unit surface in the circumferential direction of the can,
2. The can for canning according to claim 1, wherein L and w satisfy the relationship of 0.2 ≦ L / w ≦ 4. 3. The distance between the diagonal line between the crossing points that gives the maximum width in the circumferential direction of the structural unit surface and the diagonal line between the crossing points that gives the maximum axial length of the structural unit surface (the length of the line connecting the diagonal lines at right angles to each other). ) Is d0, and d1 is the distance between the position where the measurement line of the distance d0 intersects the constituent unit surface and the diagonal line between the crossing points that gives the maximum axial length of the constituent unit surface. 4. The can for canning according to claim 1 or 2, wherein the value is within a range satisfying 0.5 ≦ d1 / d0 ≦ 2. 4. The boundary ridge line portion where the constituent unit surfaces are in contact with each other is a single-point bend or a multiple-point bend portion having a gentle and constant R (radius of curvature), and the R is the plate thickness t and the can body radius r. On the other hand, the can for canning according to any one of claims 1 to 3, characterized in that it is within a range satisfying the formula: t ≤ R ≤ (2/3) r.