Synthetic resin container and method for manufacturing the same

Abstract

To provide a superior synthetic resin container that enhances the texture, aesthetics, and other qualities that can be evoked from the entire container. [Solution] Identical outer perimeter wall irregularities 13 and inner perimeter wall irregularities 14 are formed at symmetrical positions on the inner 12A and outer 12B of the perimeter wall portion 12 of the container 1. The outer perimeter wall pattern portion 15 formed by the outer perimeter wall irregularities 13 and the inner perimeter wall pattern portion 16 formed by the inner perimeter wall irregularities 14 form an identical perimeter wall pattern on the inner 12A and outer 12B of the perimeter wall portion 12. In addition, identically shaped outer bottom surface irregularities 17 and inner bottom surface irregularities 18 are formed at symmetrical positions on the inner 11A and outer 11B of the bottom surface portion 11. The outer bottom surface pattern portion 19 formed by the outer bottom surface irregularities 17 and the inner bottom surface pattern portion 20 formed by the inner bottom surface irregularities 18 form an identical bottom surface pattern on the inner 11A and outer 11B of the bottom surface portion 11.

Description

Technical Field

[0001] The present invention relates to a synthetic resin container manufactured using a plastic material and a method for manufacturing the same.

Background Art

[0002] In recent years, even in the field of food containers, for example, using synthetic resins such as polyolefin and polystyrene, injection molding is performed between male and female molds, heated and melted within press thermoforming, and after injection, cooled by injection molding to manufacture synthetic resin containers. By such injection molding, a synthetic resin container body composed of a bottom surface portion and a peripheral wall portion rising from the bottom surface portion is manufactured in large quantities and at low cost.

[0003] As a synthetic resin container, for example, as described in Patent Document 1 above, those that enhance the aesthetic property of the container by applying a pattern to the outer surface of the container are known.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the synthetic resin container described in Patent Document 1, no pattern is formed on the inner surface, and food does not adhere to the inner surface of the container, resulting in an easy-to-use effect. On the other hand, there may be a visual mismatch between the pattern on the outer surface of the container and the patternless inner surface of the container, and as a result of trial and error, findings (concerns) such as insufficient texture or aesthetic property of the entire container have been reached.

[0006] Furthermore, it was found that if consumers perceive a lack of quality or aesthetic appeal when viewing food (e.g., meals, prepared foods, sweets, etc.) in food containers displayed in stores, they will not be inclined to purchase the food (including the food containers), and consequently, this will not stimulate demand for food containers (challenge).

[0007] This invention was made to solve the above-mentioned problems. Its purpose is to provide an excellent synthetic resin container that can enhance the texture, aesthetics, etc., resulting from the integrated front and back surfaces of the entire synthetic resin container, thereby stimulating demand for the container. Another object of this invention is to provide an excellent manufacturing method that can produce the above-mentioned excellent synthetic resin container. [Means for solving the problem]

[0008] To achieve the above objectives, the present invention has the following means. Specifically, as means 1, a synthetic resin container having a bottom portion and a peripheral wall portion rising from the bottom portion, wherein the container body is formed by injection molding, and identical outer peripheral wall irregularities and inner peripheral wall irregularities are formed at symmetrical positions on the inside and outside of the peripheral wall portion, and the outer peripheral wall pattern portion formed by the outer peripheral wall irregularities and the inner peripheral wall pattern portion formed by the inner peripheral wall irregularities form the same peripheral wall pattern on the inside and outside of the peripheral wall portion.

[0009] As a second means, in the synthetic resin container described in means 1, identical outer bottom surface irregularities and inner bottom surface irregularities are formed at symmetrical positions on the inside and outside of the bottom surface, and the outer bottom surface pattern formed by the outer bottom surface irregularities and the inner bottom surface pattern formed by the inner bottom surface irregularities form the same bottom surface pattern on the inside and outside of the bottom surface.

[0010] As a means 3, a manufacturing method for producing a synthetic resin container in which the container body having a bottom portion and a peripheral wall portion rising from the bottom portion is formed by injection molding, is characterized by comprising a preparation step of preparing one mold and another mold facing one mold for forming an outer peripheral wall portion with identically shaped outer peripheral wall irregularities and an inner peripheral wall portion with identically shaped inner peripheral wall irregularities at symmetrical positions on the inside and outside of the peripheral wall portion of the container body; a molding step of heating and melting synthetic resin between one mold and the other mold and then cooling and molding the heated and melted synthetic resin between one mold and the other mold; and a removal step of removing the container body molded in the molding step.

[0011] Means 4 is a manufacturing method for producing a synthetic resin container as described in Means 3, characterized by comprising: a preparation step of preparing one mold and another mold facing one mold for forming an outer bottom surface with irregularities and an inner bottom surface with irregularities of the same shape at symmetrical positions on the inside and outside of the bottom surface of the container body; a molding step of heating and melting synthetic resin between one mold and the other mold and then injection molding, followed by cooling and molding the heated and melted synthetic resin between one mold and the other mold; and a removal step of removing the container body molded in the molding step. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide an excellent synthetic resin container that can stimulate demand for containers by enhancing the texture, aesthetics, etc., that are induced from the entire container by the integration of the front and back surfaces. Furthermore, it is possible to provide an excellent manufacturing method that allows for the easy production of the above-mentioned excellent synthetic resin container. [Brief explanation of the drawing]

[0013] [Figure 1] This is a front view of the synthetic resin container of this embodiment. [Figure 2] Figure 1 is a plan view of a synthetic resin container. [Figure 3] Figure 1 is a bottom view of the synthetic resin container. [Figure 4](A) and (B) are cross-sectional views of the main part obtained by cutting a part of the peripheral wall of the container shown in Fig. 1, and (B) is a modified example of (A). [Figure 5] It is an explanatory view showing one type and the other type used for manufacturing the container shown in Fig. 1. [Figure 6] (A) is a front view of the main part showing a part of the film attached to the surface of one type shown in Fig. 5, and (B) is a part of the film attached to the surface of the other type.

Explanation of Reference Numerals

[0014] 1 ··· Container (container made of synthetic resin), 10 ··· Container body, 11 ··· Bottom part, 11A ··· Inside of the bottom part 11, 11B ··· Outside of the bottom part 11, 12 ··· Peripheral wall part, 12A ··· Inside of the peripheral wall part, 12B ··· Outside of the peripheral wall part, 13 ··· Outer peripheral wall concavo-convex part, 14 ··· Inner peripheral wall concavo-convex part, 15 ··· Outer peripheral wall pattern part, 16 ··· Inner peripheral wall pattern part, 17 ··· Outer bottom surface concavo-convex part, 18 ··· Inner bottom surface concavo-convex part, 19 ··· Outer bottom surface pattern part, 20 ··· Inner bottom surface pattern part

Embodiments for Carrying Out the Invention

[0015] Hereinafter, embodiments in which the synthetic resin container of the present invention is embodied will be described with reference to the drawings. The synthetic resin container refers to a container manufactured by injection molding a synthetic resin (plastic material) such as polyolefin, etc., and may be hereinafter abbreviated as "food container", "synthetic resin container", etc. The synthetic resin may be other than polyolefin, for example, polystyrene resin or other resins.

[0016] The term "parallel" (described below) used in the following description is not limited to parallel in the strict sense, but includes those that can be regarded as parallel in the technical field in which a container made of synthetic resin is manufactured (hereinafter referred to as the said technical field). Similarly, the term "horizontal" (described below) is not limited to horizontal in the strict sense, but includes those that can be regarded as horizontal in the said technical field. Similarly, the term "vertical" direction used in the present text is not limited to the vertical (up and down) direction in the strict sense, but includes those that can be regarded as the vertical (up and down) direction in the said technical field.

[0017] The vertical (up and down) direction coincides with the Z-axis direction shown in FIGS. 1 to 4. Also, the left-right direction and the front-back direction are described using the "X-axis" or "Y-axis direction" in the container shown in FIGS. 1 to 4 and the manufacturing apparatus shown in FIGS. 5 and 6. The Y-axis direction and the X-axis direction are orthogonal to each other, and the direction intersecting the Y-axis direction and the X-axis direction is referred to as the "Z-axis direction".

[0018] FIGS. 1 to 3 are the front view, plan view, and bottom view of the container 1. Further, FIG. 4(A) shows an enlarged view of the main part when a part of the peripheral wall of the container 1 in FIG. 1 is cut. FIG. 5 is an explanatory view showing the one-type and the other-type used in the manufacturing method for manufacturing the container 1 in FIG. 1. FIG. 6(A) is a main part front view showing a part of the film attached to the surface of the one-type in FIG. 5, and (B) is a main part front view showing a part of the film attached to the surface of the other-type in FIG. 5. The horizontal, vertical, and left-right directions of the container are based on the state where the food container 1 shown in FIG. 1 is placed on the horizontal plane G.

[0019] The food container 1 includes a container body 10 disposed on a high platform 9 as a leg, as shown in FIGS. 1 to 3. The container body 2 includes a storage space 1B that can store food through an opening surrounded by a mouth 1A. For example, a single serving of food can be stored in the storage space 1B, but the storage space 1B may have various other sizes (large, medium, and small storage capacities). Examples of the food include meals, side dishes, desserts, etc., but other foods may also be used.

[0020] Food container 1 may be implemented in ways other than the rice bowl shown in Figures 1 to 3, such as a lidless chawanmushi bowl, a lidless yunomi cup, a lidless donburi bowl, a soup bowl, etc., or it may be implemented with a lid, or even as a container for drinking only, not for eating. Furthermore, container 1 can be implemented in a cylindrical shape with a cylindrical bottom and surrounding walls rising from the bottom, or in other shapes.

[0021] The container described in Patent Document 1 has a pattern formed on its outer surface, but not on its inner surface. When a container has a pattern on its outer surface but not on its inner surface, as described in Patent Document 1, it can create a mismatch (a sensory inconsistency) for consumers. Such a mismatch can fail to stimulate appetite for the food placed in the container (e.g., rice, side dishes, sweets, etc.) and thus reduce the consumer's desire to purchase it.

[0022] In investigating the reasons for this, after much trial and error, a concern emerged: a lack of overall texture or aesthetic appeal in the container. In other words, when consumers see food (e.g., rice, prepared foods, sweets, etc.) placed in food containers displayed in stores, for example, it was found that if the texture or aesthetic appeal is not evoked, it does not lead to an desire to purchase the food container, and consequently does not stimulate demand for food (including food containers). Through trial and error, it was found that if the uneven pattern on the outer surface of the container and the uneven pattern on the inner surface of the container are created to form the same pattern, it is possible to prevent a lack of overall texture or aesthetic appeal in the container. Here, "texture" refers to the visual and tactile sensations of a material, but can be broadly interpreted to include the feeling (impression) received upon encountering something. It can also include positive characteristics that are subtly perceived from the object. Furthermore, "aesthetics," in addition to the aesthetics used in design law, can sometimes refer to the ability to evaluate beauty and aesthetic value.

[0023] The actual container 1 comprises a container body 10 as shown in Figures 1 to 3. The container body 10 comprises a bottom portion 11 and a peripheral wall portion 12 rising from the bottom portion 11, and is formed by an injection molding manufacturing method (described later). In this case, the peripheral wall portion 12 rises at the boundary 11C between the bottom portion 11 and the peripheral wall portion 12, but other configurations such as providing a stepped portion may also be adopted. In the container 1, identical outer circumferential wall irregularities 13 (collectively referred to as either convex or concave portions, or both) and inner circumferential wall irregularities 14 (collectively referred to as either either convex or concave portions, or both) are formed at symmetrical positions on the inner 12A and outer 12B of the circumferential wall portion 12. The outer circumferential wall pattern portion 15 (see Figure 3) formed by the outer circumferential wall irregularities 13 and the inner circumferential wall pattern portion 16 (see Figure 2) formed by the inner circumferential wall irregularities 14 form identical circumferential wall patterns on the inner 12A and outer 12B of the circumferential wall portion 12.

[0024] The symmetrical positions of the inner 12A and outer 12B of the peripheral wall 12 may be point-symmetrical with respect to the center point K2 of the peripheral wall 12 shown in Figure 4(A), or they may be line-symmetrical with respect to the center line K1. Alternatively, the symmetrical positions of the inner 12A and outer 12B may be set such that the coordinate points (X,Y,Z) of the outer 12B are separated by the thickness of the peripheral wall 12 with respect to the coordinate points (X,Y,Z) of the inner 12A.

[0025] Specifically, the outer perimeter wall protrusions 13 and inner perimeter wall protrusions 14 are formed on the inner 12A and outer 12B of the perimeter wall portion 12 shown in Figure 4(A), etc., for a few millimeters. The outer perimeter wall pattern portion 15 formed by the outer perimeter wall protrusions 13 is formed in a wood grain pattern (such as the wood grain pattern commonly found in wood) as shown in Figures 1 and 3, and the inner perimeter wall pattern portion 16 formed by the inner perimeter wall protrusions 14 is similarly formed in a wood grain pattern (such as the wood grain pattern commonly found in wood) as shown in Figure 2.

[0026] The wood grain pattern may be a pattern that imitates trees growing naturally in the wild (natural wood or unprocessed wood), or it may be a pattern that imitates unprocessed wood (including the cut surface (annual rings, etc.)) (the same applies hereafter).

[0027] Wood grain patterns encompass a variety of wood grain patterns, with representative examples including annual ring patterns, flat grain patterns, and straight grain patterns. However, the color often differs where there are knots. Therefore, even if wood grain patterns appear similar, they are subtly different, and wood grain patterns are often said to have "individuality." Just like actual wooden vessels, wood grain patterns are effective in reproducing the texture of wood well from containers made of synthetic resin materials.

[0028] Regarding wood grain patterns having such characteristics, it has been found that when the wood grain pattern formed from the inner peripheral wall irregularities 14 on the inner side 12A of the peripheral wall 12 and the wood grain pattern formed from the outer peripheral wall irregularities 13 on the outer side 12B are created to form the same peripheral wall pattern (such as the wood grain pattern generally found in wood), the overall texture or aesthetics of the container body 10 is significantly improved. Furthermore, it is important to improve the overall texture or aesthetics of the container body 10. For example, as shown in Figure 4(B), recesses 13O may be formed on the outer surface 12B as outer peripheral wall irregularities 13. A wood grain pattern may also be formed by the outer peripheral wall pattern portion 15O formed from the outer peripheral wall recesses 13O. Therefore, as a uniform pattern, recesses (protrusions) may be formed on the inner surface 12A as well as recesses (protrusions) on the outer surface 12B, or vice versa.

[0029] For example, wood grain patterns that align with consumers' preference for natural materials often attract consumer interest, and patterns of natural wood or wood grain are particularly popular. Therefore, products that evoke a sense of style by focusing on natural materials (for example, food containers for holding food) generate consumer purchasing intent. For example, if the outer peripheral wall pattern portion 15 and the inner peripheral wall pattern portion 16 consist of the above-mentioned uneven wood grain pattern, the demand for the container will be further stimulated, and the product embodying the present invention will have a significant industrial effect. The outer peripheral wall pattern portion 15 and the inner peripheral wall pattern portion 16 may also consist of concrete patterns in which uneven parts of the front and back are formed by parallel cross-sections, resulting in identical forms. If the height of the protrusions and the depth of the recesses of the uneven outer peripheral wall pattern portion 15 and the inner peripheral wall pattern portion 16 are large, the pattern will be enriched with shadows depending on the angle of light it receives, giving it a favorable texture and excellent aesthetics.

[0030] Furthermore, identically shaped outer bottom surface irregularities 17 (collectively referred to as either a convex portion or a concave portion, or both) and inner bottom surface irregularities 18 (collectively referred to as either a convex portion or a concave portion, or both) are formed at symmetrical positions on the inner 11A and outer 11B of the bottom surface 11. The outer bottom surface pattern portion 19 formed by the outer bottom surface irregularities 17 and the inner bottom surface pattern portion 20 formed by the inner bottom surface irregularities 18 form the same bottom surface pattern on the inner 11A and outer 11B of the bottom surface portion 11.

[0031] Specifically, the outer bottom surface irregularities 17 and the inner bottom surface irregularities 18 have irregularities of several millimeters. The outer bottom surface pattern 19 formed by the outer bottom surface irregularities 17 has a star-shaped pattern as shown in Figure 3, and the inner bottom surface pattern 20 formed by the inner bottom surface irregularities 18 similarly has a star-shaped pattern as shown in Figure 2.

[0032] By applying the same type of embossed pattern (star-shaped pattern on the outer bottom surface pattern 19 and the inner bottom surface pattern 20) to both the inner surface 11A and the outer surface 11B of the bottom surface 11, it becomes possible to express texture, aesthetics, etc., which are said to be difficult to express in the case of a synthetic resin container 1 made by injection molding, and improve the texture and aesthetics that are brought about by the unified front and back of the synthetic resin container 1 as a whole.

[0033] Furthermore, the outer bottom surface pattern 19 formed by the outer bottom surface irregularities 17 may be wood grain-like (wood grain patterns or other patterns commonly found on wooden vessels), similar to the outer surface 12B of the peripheral wall 12. Similarly, the inner bottom surface pattern 20 formed by the inner bottom surface irregularities 18 may be wood grain-like, similar to the inner surface 12A of the peripheral wall 12. By applying the same bottom surface irregularity pattern (wood grain pattern) to the inner surface 11A and outer surface 11B of the bottom surface 11 in this way, even a synthetic resin container 1 made by injection molding can express a texture that is not present in synthetic resin containers 1.

[0034] When the same type of uneven pattern (wood grain pattern) is applied to both the inner surface 11A and the outer surface 11B of the bottom surface 11 (inner surface and outer surface of the bottom surface), and to both the inner surface 12A and the outer surface 12B of the peripheral wall 12 (inner surface and outer surface of the peripheral wall), the same effect is achieved as when the outer peripheral wall pattern portion 15 and the inner peripheral wall pattern portion 16 are made of a wood grain pattern.

[0035] Furthermore, if the same type of uneven pattern is applied to both the inner surface 12A and the outer surface 12B of the peripheral wall portion 12, it may be possible to express texture, aesthetics, etc., that are difficult to express with synthetic resin containers made by injection molding. If it is possible to enhance either the texture or aesthetics, etc., that are derived from the entire food container 1 by the integration of the front and back surfaces, it may be possible to further stimulate demand for the food container 1.

[0036] Injection molding is a method of molding in which plastic material is heated and melted, then fed into a mold, and cooled within the mold. Because it can mass-produce parts of various shapes in a continuous manner, it is used in the manufacturing process of food containers, enabling inexpensive mass production. In injection molding dies, in order to make the front and back surfaces of an injection-molded body of a specific shape identical in relief and relief, the same in relief and relief pattern shown in Figures 6(A) and 6(B) is transferred to the symmetrical position by methods such as blasting or etching on the surfaces of one metal mold into which the resin is injected and the other mold opposite it (preparation process). Basically, it consists of two molds, a fixed side and a movable side, and employs a process of opening and closing using a mold clamping unit.

[0037] The injection molding manufacturing apparatus 30 used in this implementation will be described with reference to Figure 5. Molten synthetic resin material 34 is injected under pressure through a gate into the gap 33 between the fixed mold 31 and the movable mold 32 (injection molding). As a result, the synthetic resin material 34 is used to manufacture the container body 10 as an injection molded product, which is then removed from the fixed mold 31 and the movable mold 32 after it has cooled and solidified (removal process).

[0038] As an alternative molding method, the film shown in Figure 6(A) can be inserted into the gap 33 along the surface 31A of the fixed mold 31. When the film shown in Figure 6(A) is inserted into the gap 33 (preparation step), the outer peripheral wall pattern portion 15 (see Figure 3) formed by the outer peripheral wall irregularities 13 can be formed in the above manufacturing process. In this case, the recesses 15A (13A) of the film shown in Figure 6(A) correspond to the protrusions 15 (13) shown in Figure 1, so a consistent pattern can be formed with good reproducibility. Similar to the outer peripheral wall pattern portion 15 formed by the outer peripheral wall irregularities 13, an outer peripheral wall pattern portion 19 can be formed by the outer bottom surface irregularities 17. In this case, a consistent pattern can be formed with good reproducibility.

[0039] Furthermore, the film shown in Figure 6(B) can be inserted into the gap 33 so as to follow the surface 32A of the movable mold 32. When the film shown in Figure 6(B) is inserted into the gap 33 (preparation step), the inner peripheral wall pattern portion 16 (see Figure 2) formed by the inner peripheral wall irregularities 14 can be formed in the above manufacturing process. In this case, the recesses 16A (14A) of the film shown in Figure 6(B) correspond to the protrusions 16 (14) shown in Figure 1, so a consistent pattern can be formed with good reproducibility. In the same way as the inner peripheral wall pattern portion 16 formed by the inner peripheral wall irregularities 14, an inner peripheral wall pattern portion 20 formed by the inner bottom surface irregularities 19 can be formed. In this case, a consistent pattern can be formed with good reproducibility.

[0040] Furthermore, since the injection molding dies are manufactured separately for the male and female molds, the outer peripheral wall irregularities 13 and the inner peripheral wall irregularities 14, which have the same shape, do not perfectly match. However, this does not pose any particular problem in terms of improving texture, aesthetics, etc.

[0041] As described above, the food container 1 has a container body 10 comprising a bottom portion 11 and a peripheral wall portion 12 rising from the bottom portion 11, which is formed by injection molding. In the container 1, an outer peripheral wall uneven portion 13 and an inner peripheral wall uneven portion 14 of the same shape are formed at symmetrical positions on the inner 12A and outer 12B of the peripheral wall portion 12, and the outer peripheral wall pattern portion 15 formed by the outer peripheral wall uneven portion 13 and the inner peripheral wall pattern portion 16 formed by the inner peripheral wall uneven portion 14 form the same peripheral wall pattern on the inner 12A and outer 12B of the peripheral wall portion 12, as well as on the inner 11A and outer 11B of the bottom portion 11. At symmetrical positions, identical outer bottom surface irregularities 17 and inner bottom surface irregularities 18 are formed, and the outer bottom surface pattern 19 formed by the outer bottom surface irregularities 17 and the inner bottom surface pattern 20 formed by the inner bottom surface irregularities 18 form identical bottom surface patterns on the inside 11A, outside 11B, and outside of the bottom surface 11, thereby enhancing the texture, aesthetics, etc., that can be induced from the entire food container 1 as a unified front and back surface. If an inner peripheral wall irregularity 14 is formed on the inside 12A of the food container 1, the food may adhere to the inner peripheral wall irregularity 14, making it easier to remove the food.

[0042] Furthermore, the above-described method for manufacturing a synthetic resin container provides a manufacturing method for producing an excellent synthetic resin container 1 by providing a preparation step of preparing one mold and another mold facing one mold for forming an outer periphery wall portion 12 with identically shaped outer periphery wall irregularities 13 and an inner periphery wall portion 12 with identically shaped inner periphery wall irregularities 14 at symmetrical positions on the inner 12A and outer 12B of the periphery wall portion 12 of the container body 10, and an outer bottom surface portion 11 with identically shaped outer bottom surface irregularities 11B and an inner bottom surface portion 11A with identically shaped inner bottom surface irregularities 11 at symmetrical positions on the inner 11A and outer 11B of the bottom surface portion 11 of the container body 10; a molding step of heating and melting synthetic resin between one mold and the other mold and then cooling and molding the heated and melted synthetic resin between one mold and the other mold; and a removal step of removing the container body molded in the molding step.

[0043] Furthermore, the synthetic resin container of the present invention is not limited to the above-described embodiments, and various modifications and combinations are possible within the scope of the claims and embodiments, and these modifications and combinations are also included within the scope of the patent rights. The synthetic resin container of the present invention is not limited to synthetic resin food containers, but may also be implemented in synthetic resin containers used in daily life.

Claims

1. In a synthetic resin container in which the container body, comprising a bottom portion and a peripheral wall portion rising from the bottom portion, is formed by injection molding, Identical outer and inner perimeter wall irregularities are formed at symmetrical positions on the inner and outer sides of the perimeter wall. A synthetic resin container characterized in that the outer peripheral wall pattern formed by the outer peripheral wall irregularities and the inner peripheral wall pattern formed by the inner peripheral wall irregularities form the same peripheral wall pattern on the inside and outside of the peripheral wall.

2. In the synthetic resin container according to claim 1, Identical outer bottom surface irregularities and inner bottom surface irregularities are formed at symmetrical positions on the inner and outer sides of the bottom surface. A synthetic resin container characterized in that the outer bottom surface pattern formed by the outer bottom surface irregularities and the inner bottom surface pattern formed by the inner bottom surface irregularities form the same bottom surface pattern on the inside and outside of the bottom surface.

3. In a manufacturing method for producing a synthetic resin container in which the container body, having a bottom portion and a peripheral wall portion rising from the bottom portion, is formed by injection molding, A preparation step of preparing one mold and the other mold facing the first mold for forming an outer peripheral wall portion with identically shaped outer peripheral wall irregularities and an inner peripheral wall portion with identically shaped inner peripheral wall irregularities at symmetrical positions on the inner and outer sides of the peripheral wall portion of the container body, A molding process in which a synthetic resin is heated and melted between one mold and the other mold and then injection molded, and the heated and melted synthetic resin is cooled and molded between the one mold and the other mold, A manufacturing method for producing a synthetic resin container, characterized by comprising a removal step for removing the container body molded in the molding step.

4. In a manufacturing method for producing a synthetic resin container as described in claim 3, A preparation step of preparing one mold and another mold facing the first mold for forming an outer peripheral wall portion with identically shaped outer peripheral wall irregularities and a bottom portion with identically shaped inner peripheral wall irregularities at symmetrical positions on the inside and outside of the bottom surface of the container body, A molding process in which a synthetic resin is heated and melted between one mold and the other mold and then injection molded, and the heated and melted synthetic resin is cooled and molded between the one mold and the other mold, A manufacturing method for producing a synthetic resin container, characterized by comprising a removal step for removing the container body molded in the molding step.

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