JPH0457733A - Lid-sealed type plastic container and its manufacture - Google Patents

Abstract

PURPOSE:To achieve a major improvement in the strength to deformation under external pressure (or reduction in internal pressure) and add a fine characteristic appearance by juxtaposition of constituent unit planes in which the ridgeline-forming boundaries and their intersections jut out from the barrel relatively in relation to the constituent unit planes, and the constituent unit planes set contiguously in the axial direction of the barrel are ranged with a phase difference. CONSTITUTION:Quadrangles as constituent unit planes constitute a multiplane wall. In this multiplane wall, each of the constituent unit planes consists of substantially a rhombus and is gently curved in the form of an outward convex along the plane lines connecting (a)-(c) and (b)-(d) (along the plane lines connecting apexes and extending in the axial and circumferential directions). These constituent unit planes form the side of the container by their contiguous juxtaposition in the circumferential direction as well as in the axial direction with a phase difference of l/2. But the ridgeline-forming boundaries of the constituent unit planes of the multiplane wall are not arranged in the axial direction of the container. The juxtaposition of quadrangular constituent unit planes in this manner brings about an improvement much greater than is expected in their strength to deformation of the barrel under external pressure (or reduction in internal pressure).

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a plastic container with a sealed end lid, such as a heat seal container or a plastic can.
More specifically, a plastic container with an end lid that is resistant to buckling due to external pressure and has excellent resistance to deformation under reduced pressure during the cooling process after filling the contents or during subsequent storage, and the manufacture thereof. Regarding the method.

(Prior art) A plastic container that has been given sealing performance by heat sealing consists of a container body molded from thermoplastic resin and a lid made of metal foil laminated with thermoplastic resin film on both sides. It is formed into a cylindrical shape or a truncated conical tube shape, and a flange is formed at the end thereof, and the lid is peat-sealed to the flange surface. Further, the container body may be made of a layered material such as metal foil in addition to thermoplastic resin.

In addition, the engagement between the plastic container body and the metal lid
So-called plastic cans, which are made by wrapping the A parts together, have been known for a long time, as seen in Japanese Utility Model Publication No. 37-25894, and the plastic container body can be made by blow molding from a pipe or by blow molding a cup material. It is molded by ladder processing.

Examples of resins used for plastic containers include polyester, polyamide, polycarbonate, polyvinylidene chloride, acrylonitrile polymer, styrene resin, polypropylene, and ethylene vinyl alcohol.
These materials may be used alone, in a blend, or in a multilayered form depending on the purpose.

(Problem to be solved by the invention) Usually, the body of a plastic bottle (one whose end is not sealed with a lid) has beads formed in the circumferential or axial direction to provide reinforcement against external pressure. Ru. However, even if a circumferential bead or an axial bead is provided on the body, decompression deformation and press deformation due to temperature changes easily occur. Decompression deformation damages the appearance of the container, but
In the case of plastic cans, irreversible deformation may occur.

In addition, pressure deformation and depressurization deformation cause the container to buckle and cause the container to break.

In the case of plastic containers, many efforts are being made to reduce the thickness of the material in order to reduce the material cost and to make the container itself lighter. However, it is clear that if the wall thickness of the plastic container is made even thinner, the container will buckle even more than it currently does.

Furthermore, when sealing a can or the like, the can body is usually gripped from the outside while the contents are inside. If the can is made of metal or other steel, there is no problem as it has a certain level of rigidity, but if it is a plastic can, delicate training is required to grip the can, and if the can is gripped too tightly, the can body may become damaged. Unusual deformation or buckling deformation occurs, making it difficult to tighten.

Therefore, an object of the present invention is to introduce a new reinforcing structure to replace the conventional bead, which significantly improves the deformation strength due to external pressure (or internal depressurization), and has good appearance characteristics. It is an object of the present invention to provide a plastic container with a sealed end lid that is easy to operate, and to provide a method for manufacturing the same.

Another object of the present invention is that the outer surface of the plastic container has a unique three-dimensional effect and aesthetic appearance based on a polyhedron, is easy to grasp when drinking the contents, and is resistant to dents. An object of the present invention is to provide a plastic container with a closed lid.

(Means for Solving the Problem) According to the present invention, in a plastic container in which a lid or the like is sealed to an end portion by adhesion, heat sealing, or seaming, the container body has a cylindrical or conical shape, A circumferential polyhedral wall is formed in at least a portion of the container body, and the polyhedral wall has a constituent unit face, a boundary ridgeline where the constituent unit faces touch each other, and an intersection where the boundary ridgelines intersect, and the boundary 12 line and The intersecting part is relatively convex to the outside of the container body compared to the structural unit surface, and the adjacent container side unidirectional arrangement of the structural unit surface is arranged with a phase difference. Provided is an end-sealed plastic container that is resistant to deformation.

According to the present invention, there is also a method for manufacturing a plastic container in which a lid or the like is sealed to the end portion by adhesion, heat sealing, or seaming, in which the container body material is formed into a cylindrical or truncated conical shape, and the container A split mold is placed on the outside of the body,
Pressure is applied from inside the container body to press the container side wall against the inner surface of the split mold to form a circumferential polyhedral wall on at least a portion of the container body, and the polyhedral wall forms a boundary between a constituent unit surface and a boundary where the constituent unit surfaces contact each other. It has an intersection where the ridge line and the boundary I2&& intersect with each other, and the boundary ridge line and the intersection are relatively convex to the outside of the container body compared to the constituent unit plane, and the boundary ridge line and the intersection part are relatively convex to the outside of the container body compared to the constituent unit plane in the axial direction of the container body adjacent to the constituent unit plane. So that the arrays are arranged with a phase difference,
There is provided a method for manufacturing an end-lid sealed plastic container, characterized in that a circumferential polyhedral wall is formed using the split mold.

(Function) The present invention forms a polyhedral wall on a plastic container body, particularly one having a cylindrical shape or a truncated conical shape. By forming the unit surfaces so that they are convex and arranging adjacent containers in the M-axis direction with a phase, especially a phase difference of 1/2, the containers are extremely resistant to deformation against external pressure. This is based on the knowledge that In addition, we have found that when it is formed not only on the entire surface of the container body but also on a part of the container body, especially when it is formed in the center of the container body, it has sufficient deformation resistance. If the circumferential polyhedral wall accounts for 10% or more of the entire surface, sufficient effects can be obtained.

These polyhedral walls can be easily formed at multiple positions on the container body, and in the present invention, the number of constituent unit faces present around the circumference of the container body is important, and the number of constituent unit faces present around the circumference is important. The number n of unit surfaces is 3 or more, especially 3 to 1, not including those that are phased in the axial direction on the 4# side.
It is important that the value be within the range of 4. In particular, 4 to 12 is preferable for quadrilaterals, which will be described later, and 3 for hexagons.
A value between 10 and 10 is desirable.

FIG. 4 shows the relationship between the empty container external pressure resistance ratio of the plastic can body (the ratio of the case where the structural unit surface is applied and the case where it is not applied) and the number n. As shown in FIG. 4, as n increases, the effect decreases, and when n exceeds 14, the effect of the empty container's external pressure resistance is hardly seen. On the other hand, n is 3
If it is less than 100 ml, it will not be possible to form a sufficient multifaceted wall surface on the plastic can body, and the appearance will be poor because the surface will be severely bent. Note that the container body may be cylindrical or truncated conical.

Even if the constituent unit surfaces applied to the plastic tray are quadrilaterals, hexagons, or almost circular with rounded corners, as described below, the multifaceted walls are convex inward as described above. If it is formed of constituent unit planes that are in phase, especially constituent unit planes that are approximately 1/2 in phase, it will have sufficient deformation resistance.

When a conventional conventional container body is viewed from the side for a recessed capacity with such a configuration, the outline of the container body appears as an iii line in the axial direction, but the outline of the container body appears as an iii line in the axial direction. 8th
As shown in FIGS. 12-B and 18, the constituent unit surfaces appear curved in the axial direction or as V-shaped depressions. With the configuration of such a unit surface.

The half-shaped phase arrangement imparts deformation resistance to the container body, and also enables molding while keeping the surface area of the container body before the formation of the polyhedral wall substantially equal to the surface area of the container body after the formation of the polyhedral wall. Become. The body of a plastic container having such a polyhedral wall is resistant to deformation and buckling, both under pressure and under reduced pressure. Moreover, in the case of plastic cans, when such a polyhedral wall is formed around the seaming part, it becomes easier to hold the plastic can during seaming.

(Preferred Embodiments of the Invention) Hereinafter, preferred embodiments of the end lid sealed plastic container according to the present invention will be described in detail with reference to the accompanying drawings.

As shown in Figure 1, the plastic container according to the present invention is produced by stretching a pipe (Figure 1 (A)), subjecting it to plow molding (Figure 311 (B)), and performing flanging (II).
Figure 11(C)) A container body material is formed. In addition, in some cases, the injection molded cup may be squeezed as shown in Figure 92 (Figure II2 (A)) or cut (Figure 1r2 (B)).
Then, blow molding is performed (Figure 12 (C)) and flanging is performed (Figure 1r2 (D)) to form a container body material with one end closed. These can primarily be used as plastic cans.

In addition, as shown in Figure 113, a sheet of thermoplastic resin can be aged (thermoforming: vacuum forming, pressure forming, vacuum/
A truncated conical container material (FIG. 3(B)) with a trapezoidal cross section can be formed by air pressure forming). This container material has a flange formed at the end so that the lid can be heat-sealed.

A split mold (not shown) is disposed around the outside of such a container material, and the shape of the split mold is configured to match the shape of each multifaceted wall, which will be described later. After placing the tFJ mold, the inside of the container material is pressurized so that the side walls of the container come into close contact with the split molds, forming a plastic container having a polyhedral wall, which will be described later. In addition, the 10% type is II l II (B), the second! It may be placed during blow molding of ill (C). In addition, the polyhedral wall is injection molded,
It is also possible to form it by post-processing on a one-end closed type container body material formed by thermoforming, press molding, or blow molding. That is, after the container body is heated to the optimum temperature by the body material resin, a multifaceted wall is formed using the male mold/4 mold.

The characteristics of various structural unit surfaces are shown below.

First, in the present invention, the constituent unit faces of the polyhedral wall are constructed of quadrilaterals. That is, on a multifaceted wall surface, the 6th rgJ
As shown in (a) and (b), the constituent unit surfaces are approximately diamond-shaped, and along the surface line connecting a-C and b-d (along the surface line extending in the axis and circumferential direction connecting the vertices). ) forms a smoothly curved part, and this curved part is convex inward.

Such constituent unit surfaces are arranged adjacent to each other in the circumferential direction, and are arranged with a phase difference of 172 in the axial direction, so that the capacity a
forming the sides. However, the boundary ridges of the structural units of such multifaceted wall surfaces are not arranged along the axial direction of the container, and in the case of quadrilateral structural unit surfaces, this arrangement is difficult to avoid due to the external pressure (or body wall) of the container body. This results in an unexpected improvement in the deformation strength due to the decompression of Although the mechanism for this is not clear, it is understood that it is because the rhombic structural unit surfaces are alternately introduced and incorporated into the side wall of the container.

As shown in FIG. 6, the constituent unit surfaces of the multifaceted wall surface are rhombuses abcd. Each side ab, bc, c of a diamond
d and da are sides formed by the boundary ridge line formed on the side surface of the container, and their joint intersection is an outwardly convex vertex a,
b, c, d. In addition, as mentioned above, the line connecting bd is a smooth curved part, and the rhombus dimension is the length of bd is W and the height of aC is L, W and L are the constituent unit planes. The maximum width and maximum length in the axial direction.

The relationship between W and L is important in increasing the strength of the container can of the present invention, and also greatly affects the appearance of the container. That is, the relationship between W and L is 0. 2≦L/
It is desirable that w≦4, and this is true not only for quadrilateral structural unit surfaces but also for hexagonal and other structural unit surfaces. As shown in Figure 119, when L/w exceeds the above range, there is no problem with the appearance of the container, but the external pressure of the container ρ, which is the original purpose, decreases. On the other hand, if L/w is smaller than the above range, although the container has good external pressure resistance, the container itself is likely to be deformed due to axial compression.

This is not a problem if you use pipe material for boat fishing, but
It is understood that this is an important issue for container bodies.

Furthermore, if L/w is below this range, the appearance will be poor, and there is a risk that the appearance of the printed image on the surface of the container will be deteriorated.

In addition, each vertex a of the rhombic constituent unit surface shown in Figure 5-C
, b or d substantially protrudes most in the radial direction, is located approximately on the circumference of the center 0 of the container body and has a radius r, and is located at the center of the rhombus of the curved part of the constituent unit surface (between b and d). point) is located most inward of the diameter.

In the present invention, each side becomes a ridgeline connecting the vertices, and the central part of the rhombus is curved to form a trough, and when this multifaceted wall is formed on the container body, the container body surface area before and after the multifaceted wall is formed. The surface area of the container body can be kept substantially equal to the surface area of the container body.

Such a plastic container has improved resistance to reduced pressure and pressure resistance, and the metal lid can be easily sealed at the seaming portion shown in FIG. 5-B. In addition, the circumferential troughs are smoothly curved, which improves the reproducibility of external designs and improves the appearance, and there is almost no residual content inside the container, similar to conventional cylindrical containers. Although Fig. 7 shows a Nissin-like can container, the same effect can be obtained even when a polyhedral wall is formed on a truncated conical cylindrical container with a heat-sealed lid, as shown in Fig. 8. There is.

In addition, in the plastic container of the present invention, it is important that the depth fid of the central part of the constituent unit surface (which is depressed from the outer circumferential surface of the container body when it does not have a multifaceted wall) is defined as the radius of the container body. Then, the intersection point of the structural unit plane is located approximately on the radius of this container body, although there is a slight error in forming.On the other hand, the line connecting the intersection points bd in the circumferential direction (in the case of a quadrilateral, the structural unit (The maximum width of the surface is W.) Let S be the distance from the midpoint on the top to the center 0 of the container body.In this case, the radius r and S of the container body are used as an index representing the depth of the constituent unit surface.
If the difference between the It is important that 5≦d/d and ≦2.

FIG. 10 is a diagram plotting the relationship between the depth ratio d/d in the structural unit plane and the external pressure resistance of the empty container.

As shown in FIG. 10, if the depth ad of the structural unit surface is smaller than the range of the above relationship, sufficient resistance against external pressure as shown in FIG. 4 cannot be obtained. On the other hand, if the depth Ad is larger than the above range, buckling in the axial direction of the container is likely to occur. Furthermore, the printed appearance also deteriorates.

Further, d is closely related to the maximum width W of the constituent unit surface, and W is related to the maximum length L in the axial direction described above.

Therefore, the depth tel is closely related to these W and L, and its permissible range also changes depending on these lengths. For example, in the constituent unit plane of a quadrilateral, d,
= r - s, and s = r cos(π/n) + w
=2 From rsin(π/n), d, =1/2
・w (sin(π/n)) −” (1-cos(π
/n)), and it is understood that d is determined by the maximum width W and the number n of constituent unit surfaces present in the circumferential direction.

As W becomes larger, the possible range of the depth d becomes larger, and as n becomes larger, the possible range becomes smaller.

This effect of the structural unit surface can also be seen when the unit surface is formed in the center of the container body, as shown in Figure 7, and the effect of the structure formed in the center is greater than that formed only at the ends. tends to be large. Further, in the container shown in FIG. 7, it is preferable that at least 10% or more of the entire surface of the container body is formed, and the above-mentioned effects can be sufficiently observed in such a forming area.

Also, proceeding further from the state where the constituent unit surface is a quadrilateral,
The feature is that a complete fold is formed in the center of the quadrilateral which is the constituent unit plane in the above-mentioned figure jI6, so that the constituent unit plane at the end becomes an isosceles triangle as shown in figure jll-A and figure 12-A. It can be done.

In this case, the axial cross section of the constituent unit surface is V-shaped,
As shown in Figure 1112-A, the isosceles triangle ABC is the minimum surface unit (basic surface unit), and each side AB, BC, and CA of this isosceles triangle are two isosceles triangles. It is a shared relationship. The shape and dimensions of this isosceles triangle will be expressed below with the length of the base BC being W and the height of the triangle being h.

In the arrangement of the minimum surface constituent units in the present invention, the apex 2 is at the most protruding position in the radially outward direction of the container body, the base 3 is in the position concave in the radially inward direction of the container body, and the opposite sides 4 and 4 are The polyhedron composed of these can be said to be a polyhedral wall with the pair 4.4 as the ridgeline and the base 3 as the valley.

Also in such a case, 2h/w (h= 1/
It is important that the relationship of 2L) and the number n of the constituent unit planes be in the same value range as that of a quadrilateral, and in such cases the external pressure resistance of the container is fully exhibited.

In addition, in such a constituent unit surface, the depth d of the constituent unit surface is approximately equal to d, ignoring slight errors in forming, and the surface area of the container body before polyhedron formation and the polyhedron formation It is possible to keep the surface area of the subsequent container body substantially equal, and the thickness distribution within the plane of the structural unit becomes uniform, so that the container exhibits sufficient external pressure resistance.

Furthermore, the above! In order to strengthen the structural unit surface shown in FIG. 12, the structural unit surface, which is a depression, may be partially bent along the axial direction (FIG. 1113). In terms of such constituent units,
The depth d of the constituent unit surface can be reduced to approximately 2d if slight errors in molding are ignored, and the external pressure resistance of the empty container shown in Fig. 4 is greatly improved and the mechanical strength is sufficient. This has been achieved, and the stress remaining in the container body after processing is extremely small, the shrinkage rate of the container during retort sterilization and subsequent aging can be suppressed, the geometric appearance is sufficiently maintained, and the grip is excellent.

Further, in one aspect of the present invention, the constituent unit planes can be hexagonal. In this case, too! The hexagonal shape, which is the i unit surface, has a depression toward the inside with respect to the axial direction of the container body, and as shown in Figure 14 or @ 15, each constituent unit surface has approximately 172 phases in the axial direction. Placed. Also, in a container body having such a structural unit, the number n of unit surfaces present around the circumference is important, and it is desirable that the number n is 3 to 14. Even in such a configuration, the L/w ratio is important, and 0. 2≦L/w≦4
It is desirable that In addition, the maximum width of the constituent unit planes in this case is not necessarily the intersection of the constituent unit planes as shown in Figure 15, but may be the length connecting points on the boundary ridge line, and the maximum width in the axial direction. As shown in FIG. 14, the length L is not necessarily the intersection point of the constituent unit planes, but is the length that connects the points on the boundary ridge line. Further, it is desirable that the depth d of such a constituent unit surface satisfies the above range in the same manner as that of the quadrilateral. Note that the relationship of W in d is the maximum width connecting points on the ridgeline in FIG. 15 as described above.

Furthermore, as shown in FIG.
2 can be formed to have a constant radius of curvature R without having an acute corner.

Further, R can be related to the plate thickness and the radius of the volume @M, and it is desirable that R satisfies t≦R≦(2/3)D. In addition, such bending near the boundary ridgeline is one curve, that is, the maximum bending radius is 1 near the 12th line.
It may be only at one location, or there is no problem even if there are multiple fixed bending R in multiple locations, but it is desirable that the R formed near the ridge line is within the above range. .

It goes without saying that R can be formed even when the constituent unit planes are quadrilaterals as shown in FIG.

In the present invention, plastic resin or the like is molded into a cylindrical shape.

A so-called three-piece can, in which both ends of the container body are secured to a top and bottom lid, or a so-called two-piece can, in which resin is blow-molded and a lid is secured to the upper end of the bottomed container body, can be used. Furthermore, a container can be used in which a plastic resin is molded into a truncated conical tube shape, a flange surface is formed at the upper end of the container, and a lid is heat-sealed to the flange.

Container Resin In the present invention, polyester, polypropylene resin, polycarbonate, styrene resin, nylon resin, etc. can be widely used as the container resin.

Among these, thermoplastic polyester is particularly desirable. Further, in order to maintain barrier properties, the container body may be a laminate of plastic, aluminum foil, tin foil, or the like.

This is because the container body of the present invention has pressure resistance.

Physically, the rigidity of the container body that can withstand the tightening of plastic can containers can be significantly improved.

Metal lid and heat-sealed lid In the present invention, the metal lid is made of various surface-treated steel sheets such as tin-plated steel sheets and tin-free steel (electrolytic chromic acid treated @), and light metals such as aluminum, and is coated with epoxy on the surface. A coating provided with a protective coating such as a phenol paint, an epoxy-urea paint, an epoxy-acrylic paint, an epoxy-vinyl paint, or a vinyl-phenol paint is used. A circumferential groove is provided around the periphery of such a can lid for engagement with the seaming end of the container body, and this groove is lined with a sealing rubber composition. Further, the center panel portion of the can lid can be provided with a known easy-opening mechanism.

As the heat-sealing lid, a laminate in which both surfaces of a metal foil, which is known per se, are laminated with thermoplastic resin films can be used.

(Example) Examples and comparative examples are shown below.

Polyethylene terephthalate (PE) with an intrinsic viscosity of 0.95
T) was used to form a melt extrusion pipe while uniaxially stretching in the extrusion direction with a draw cone, and the inner diameter was 39.5 m + 11 mm.
．． Thickness 0.4mff1. Length 150! A lrs pipe with both ends open was molded. Next, both lN10mm of this pipe
After heating the part except for the part to about 105℃ with infrared rays, use a split mold (blow molding mold) that can hold both ends, and blow pressurized air (25 to 4/c + 1') from one end to make the radius. A pipe with an outer diameter of 50 mm and both ends open was made. Both ends of this hollow tube 10wn
Each was rapidly heated to 100°C with infrared rays, a flange was formed using a flange die, a metal lid was double-sealed to the WTM, and a plastic can with a PET body was formed - when performing the above blow molding, A fifth-A is placed in the axial center of the double-sided open hollow tube to be formed, with a width of 80+n+ over the entire circumference.
, Minimum surface structural unit shown in 5-C2 and FIG.
Example 1 is a case in which a split mold capable of forming 0.95) is used, and Comparative Example 1 is a case in which a split mold for forming a simple cylindrical tube that does not provide a minimum surface unit is used.

When external pressure was applied to the plastic cans molded in Example 1 and Comparative Example 1 and the external pressure resistance of the can body was measured, the can body of Example 1 showed 0.95 kHz/cm2, and the can body of Comparative Example 1 is 0.3J/cIl! 2 was shown.

(Effects of the Invention) According to the present invention, since a specific polyhedral wall is formed in the body of the plastic container, the plastic container has improved pressure resistance and reduced pressure resistance, and is less likely to buckle, thereby preventing the container from breaking. Prevented. Also.

Plastic cans are easy to grip when tightening, making manufacturing work easier.

[Brief explanation of the drawing]

1 and 2 are manufacturing process diagrams for a plastic can according to the present invention, Figure 113 is a manufacturing process diagram for a heat-sealing container according to the present invention, and Figure 114 is an empty container external pressure ratio of a plastic container ( The characteristic diagrams, Figure 5-A, Figure 5-B, and Figure 5-C when changing the n value and the ratio of the case where the structural unit surface is applied and the case where it is not applied are related to the present invention. An explanatory side view, vertical cross-sectional view, and horizontal cross-sectional view with a quadrilateral plane of a plastic container as a constituent unit surface, I! Figures 6 (a) and (b) are a plan view and a sectional view of the structural unit surface formed on the side surface of the plastic container according to the present invention, and Figures 1 and 7 show the structural unit surface of Figure 5 formed only in the center. Fig. II8 is a cross-sectional view of a heat-sealable container with a polyhedral wall, and Fig. JI9 is a characteristic diagram of the positive external ratio of empty containers when the L/W value of the plastic container is changed. , FIG. 10 is a characteristic diagram of the depth ratio d/d of the structural unit surface in a plastic container and the external pressure resistance strength of the empty container. FIG. 11 is an explanatory diagram of another aspect of the isosceles triangular unit surface formed on the container body of the plastic container according to the present invention, and FIGS. 12-A and 12-B show another aspect in FIG. fJ5. The explanatory side view and vertical sectional view, Figure 13 are @
A side view of another embodiment of a plastic container for cans in which the structural unit surface of FIG. 12 is further changed, and FIGS. 14 and 15 are partial side views of the plastic container for cans according to the present invention having a hexagonal hazy structure surface. Figures 16 and 17 are partial side views of a plastic container for cans according to the present invention in which the unit surface is a hexagonal unit having R, and Figure IJ18 is a partial side view of a plastic container for a can in the present invention in which the unit surface is a hexagonal unit having an R. It is a partial side view of a plastic container for cans. 1: Constituent unit surface 2: Vertex 3: Base 4: Boundary edge 20: Constituent unit surface 30: Boundary edge M 32: Vertex.

Claims (1)

[Scope of Claims] (1) A plastic container in which a lid or the like is sealed to the end portion by adhesion, heat sealing, or seaming, wherein the container body has a cylindrical or truncated conical shape, and at least one part of the container body A circumferential polyhedral wall is formed in the
The polyhedral wall has constituent unit faces, boundary edges where the constituent unit faces touch each other, and intersections where the boundary edges intersect, and the boundary edges and intersections are relatively convex to the outside of the container body compared to the constituent unit faces. It has deformation resistance against external pressure and is characterized by the fact that adjacent constituent unit surfaces are arranged in the axial direction of the container body with a phase difference. A plastic container with a sealed end. (2) The plastic can container according to claim 1, wherein a lid is attached to the end portion of the container body by seaming. (3) a flange surface is formed at the end portion of the container body;
2. The plastic container according to claim 1, wherein a lid is heat-sealed to the flange surface. (4) The number of constituent unit faces existing around the circumference of the container body and which are out of phase in the container axial direction is from 3 to 14. to the plastic container described in item 3. (5) The maximum length of the structural unit surface in the axial direction of the container body is L, the maximum width of the structural unit surface in the circumferential direction of the container side is w, and L
5. The plastic container according to claim 1, wherein: and w satisfy the relationship: 0.2≦L/w≦4. (6) The distance from the center of the container body to the line connecting the intersection points of the constituent unit surfaces or the line connecting points on the opposing boundary ridge lines to the center of the container body is s. If the distance from the intersection point or a point on the boundary line to the center is r, and the difference between r and s is d_0, then the depth d of the concave surface of the constituent unit surface is within the range of the following equation in relation to d_0. 6. The plastic container according to claim 1, wherein the plastic container is filled with a plastic container. 0.5≦d/d_0≦2 (7) The constituent unit surface is quadrilateral, each side is the boundary ridgeline, and the boundary ridgeline is arranged not along the axial direction of the container body, and is oriented toward the inside of the container. 7. The plastic container according to claim 1, wherein the plastic container is curved and convex. (8) The constituent unit surface is a quadrilateral with each side serving as the boundary ridgeline, the axial cross section is bent into a substantially V shape and becomes convex toward the inside of the container, and the constituent unit surface is further formed from two isosceles triangles. A plastic container according to any one of claims 1 to 6, characterized in that the plastic container is constructed as follows. (9) The plastic according to any one of claims 1 to 6, wherein the structural unit surface is hexagonal, each side serving as the boundary edge, and curved and convex toward the inside of the container. container. (10) The boundary ridgeline where the constituent unit surfaces touch each other is a single or multiple bent portion having a gentle constant R (radius of curvature), and the R is curved in relation to the plate thickness t and the can body radius D. 10. The plastic container according to claim 7, wherein the plastic container satisfies the range t≦R≦(2/3)D. (11) In a method for manufacturing a plastic container in which a lid or the like is sealed to the end portion by adhesion, heat sealing, or seaming, the container body material is formed into a cylindrical or truncated conical shape, and the outside of the container body is A split mold is disposed, and pressure is applied from inside the container body to press the container side wall against the inner surface of the split mold to form a circumferential polyhedral wall on at least a portion of the container body, and the polyhedral wall has a configuration with a constituent unit surface. It has a boundary ridge line where the unit surfaces touch each other and an intersection part where the boundary ridge lines intersect, and the boundary ridge line and the intersection part are relatively convex to the outside of the container body compared to the constituent unit planes, and are adjacent to the constituent unit planes. A method for manufacturing an end-lid sealed plastic container, characterized in that the divided molds form a circumferential polyhedral wall so that the matched container body axial directions are arranged with a phase difference.