JP2023183178A - Synthetic resin container - Google Patents

Abstract

To provide a container with increased lateral rigidity.SOLUTION: A synthetic resin container 1 includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5. The body portion 4 includes a body portion main surface portion 41, a body portion side surface portion 42, and a body portion corner portion 43. A cross-sectional shape of the body portion corner portion 43 includes a main surface side circular arc portion 43a from a diagonal position of the body portion corner portion 43 toward the body portion main surface portion 41, and a side surface side circular arc portion 43b from a diagonal position of the body portion corner portion 43 toward the body portion side surface portion 42. At the maximum body diameter of the body portion 4, when a long diameter of the body portion 4 is D1, a short diameter of the body portion is D2, and a diagonal diameter of the body portion is D3, a relation expressed by 1.13≤D1/D2≤1.23 and 1.06≤D3/D1≤1.12 is established, and when a curvature radius of the main surface side circular arc portion 43a is Ra, and a curvature radius of the side surface side circular arc portion 43b is Rb, a relation expressed by 0.65×Rb≤Ra≤1.15×Rb is established.SELECTED DRAWING: Figure 5

Description

The present invention relates to a synthetic resin container.

Traditionally, thermoplastic resins such as polyethylene terephthalate are used to create a cylindrical preform with a bottom by injection molding or compression molding, and this preform is then molded into a bottle shape by biaxial stretch blow molding. BACKGROUND ART Containers are used in a wide range of fields as containers for holding various beverages, various seasonings, and the like.

For this type of synthetic resin container, attempts have been made to make the container as thin as possible in order to reduce its weight and cost by reducing the amount of resin used. In recent years, the demand for thinner walls has become more and more severe, and as the walls become thinner, the rigidity of the container decreases, and external shocks can cause the shape of the container to deform into an irregular shape, resulting in a change in appearance. There is a risk that defects may occur.

For example, in a filling line for filling contents, containers are conveyed while being pressed against each other, so that so-called line pressure is applied to the containers from the lateral direction. Further, when the containers are transported in a boxed state, a lateral impact is applied to the containers due to vibrations during transportation that cause adjacent containers to collide with each other in the box. In response to such a lateral impact, Patent Document 1 discloses that in a rectangular cylindrical container with chamfered corners, the ridgeline portion where the corner wall surface and the body wall surface forming the column of the container intersect is In order to solve the problem of deformation and the formation of recesses and creases, vertical ribs are provided on such ridgelines.

Japanese Patent Application Publication No. 2006-327677

In view of the above-mentioned background art, the present inventors have discovered that unless the container shape is such that the ridgeline clearly appears along the axial direction, the problem of the ridgeline being deformed and the formation of recesses and creases can be avoided. Considering that this would not occur, the present invention was completed as a result of intensive studies to provide a container with increased lateral rigidity while creating a container shape in which the ridge line does not clearly appear along the axial direction.

The synthetic resin container according to the present invention is a synthetic resin container comprising a mouth, a shoulder, a body, and a bottom, wherein the body includes a body main surface, a body side surface, and a body. A body corner portion located between a main surface portion and the body side surface portion, the cross-sectional shape of the body corner portion being a main surface extending from a diagonal position of the body corner portion toward the body main surface portion. It includes a surface-side circular arc portion and a side-side circular arc portion extending from a diagonal position of the body corner portion toward the body side surface portion, and the major axis of the body portion is D1 at the maximum body diameter portion of the body portion, and the length of the body portion is D1, and the same short side is When the diameter is D2 and the diagonal diameter is D3, the relationships expressed as 1.13≦D1/D2≦1.23 and 1.06≦D3/D1≦1.12 hold, and the main surface When the radius of curvature of the side arc portion is Ra and the radius of curvature of the side arc portion is Rb, the configuration is such that a relationship expressed by 0.65×Rb≦Ra≦1.15×Rb holds true.

According to the present invention, the lateral rigidity at the maximum trunk diameter portion can be increased.

1 is a perspective view schematically showing a synthetic resin container according to an embodiment of the present invention. 1 is a front view schematically showing a synthetic resin container according to an embodiment of the present invention. 1 is a side view schematically showing a synthetic resin container according to an embodiment of the present invention. 1 is a plan view schematically showing a synthetic resin container according to an embodiment of the present invention. FIG. 3 is an end view taken along the line AA in FIG. 2; 3 is a BB end view of FIG. 2. FIG. 3 is a CC end view of FIG. 2. FIG. 5 is an end view taken along the line DD in FIG. 4. FIG. FIG. 5 is an end view taken along the line EE in FIG. 4;

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view schematically showing a synthetic resin container according to the present embodiment, FIG. 2 is a front view thereof, FIG. 3 is a side view thereof, and FIG. 4 is a plan view thereof. The container 1 shown in these figures has a container shape with many curved surfaces, and the boundaries where the radius of curvature changes are shown by lines, but the lines shown along the axial direction in the figures are , does not indicate the ridge lines clearly appearing on the surface of the container 1.
5 is an AA end view of FIG. 2, FIG. 6 is a BB end view of FIG. 2, FIG. 7 is a CC end view of FIG. 2, and FIG. 8 is a D-- D end view and FIG. 9 are EE end views of FIG. 4, and in these end views, the wall thickness appearing on the end face is omitted as appropriate.

A container 1 shown as an example in these figures includes a mouth portion 2, a shoulder portion 3, a body portion 4, and a bottom portion 5, and the body portion 4 has a container shape that is generally formed into a rectangular tube shape. There is.

Such a container 1 is made by using a thermoplastic resin to produce a preform shaped into a cylinder with a bottom by injection molding or compression molding, and then molding this preform into a predetermined container by biaxial stretch blow molding or the like. It can be manufactured by molding it into a shape.

As the thermoplastic resin used, any resin that can be blow molded can be used. Specifically, thermoplastic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, amorphous polyarylate, polylactic acid, polyethylene furanoate, or copolymers thereof can be used, and in particular, ethylene terephthalate such as polyethylene terephthalate can be used. Thermoplastic polyesters can be suitably used. Two or more of these resins may be mixed, or other resins may be blended. Polycarbonate, acrylonitrile resin, polypropylene, propylene-ethylene copolymer, polyethylene, etc. can also be used.
Furthermore, the preform is not limited to being formed into a single layer, but can also be formed into a multilayer structure including a gas barrier layer, etc., depending on the characteristics required of the container 1.

The mouth part 2 is a cylindrical part that serves as an inlet for the contents, and a screw thread 2a for attaching a lid (not shown) is provided on the side surface of the mouth part 2 on the open end side.
Furthermore, the mouth portion 2 is provided with an annular neck ring 2b that protrudes outward along the circumferential direction. A cylindrical neck portion 2c that hangs down from directly below the neck ring 2b with approximately the same diameter is referred to as the mouth portion 2, and the lower end of the mouth portion 2 extends between the mouth portion 2 and the body portion 4. It is connected to the connecting shoulder part 3.

The body portion 4 is a portion that occupies most of the height of the container 1, and has an upper end connected to the shoulder portion 3 and a lower end connected to the bottom portion 5.
Note that the height direction refers to the direction perpendicular to the horizontal plane when the container 1 is erected on a horizontal plane with the mouth 2 facing upward. The vertical, horizontal, and vertical and horizontal directions shall be specified.

In this embodiment, the body 4 has a rectangular cross-sectional shape with rounded corners (a cross-sectional shape cut along a plane perpendicular to the central axis C), and is arranged along the major axis direction. A trunk main surface part 41 having a straight cross-sectional shape, a trunk side part 42 having a straight cross-sectional shape arranged along the short axis direction, and the trunk main surface part 41 and the trunk side part 42. The cross-sectional shape located between the body portion is formed so as to include an arcuate body corner portion 43.

In making the cross-sectional shape of the body part 4 into such a rectangular shape, the major axis, the minor axis, and the diagonal diameter of the body part 4 may be constant along the height direction. In this case, the maximum trunk diameter portion extends over the entire trunk portion 4, but the major axis, minor axis, and diagonal diameter of the trunk portion 4 are set high so that the maximum trunk diameter portion is located at a specific part of the trunk portion 4. It may also be made to change along the horizontal direction. For example, as in the illustrated example, the major axis, minor axis, and diagonal diameter of the trunk 4 become smaller toward the central part of the trunk 4 in the height direction. The shape may be constricted at the center.

Further, in the illustrated example, the cross-sectional shape of the shoulder side end of the body 4 and the bottom side end of the body 4 are formed to be the same, and both the upper and lower ends of the body 4 are formed. It is the largest diameter part. In other words, the maximum trunk diameter portion of the trunk portion 4 is located on both the shoulder portion 3 side and the bottom portion 5 side, and the major axis, minor axis, and diagonal diameter of the trunk portion 4 at each maximum trunk diameter portion are as follows. Both are molded to be equal (see FIGS. 5 and 6).

Here, the position where the distance between the body corner parts 43 facing each other through the central axis C is maximum is defined as the diagonal position, and when blow molding the container 1, the parting line is set along the diagonal position. can be arranged. The length of the line segment connecting each diagonal position is defined as the diagonal diameter of the body portion 4.
In addition, in FIGS. 5 and 6, the line segment connecting the diagonal positions is shown by a dashed-dotted line.

More specifically, the cross-sectional shape of the body 4 is such that the major axis (maximum major axis) at the maximum body diameter is D1, the short axis (maximum minor axis) is D2, and the diagonal diameter (maximum diagonal When the diameter) is D3, it has a rectangular shape that satisfies the relationship expressed by 1.13≦D1/D2≦1.23, and its corners satisfy 1.06≦D3/D1≦1.12. It is rounded into an arc shape so that the expressed relationship holds true. As a result, the boundary between the body main surface 41 and the body corner 43 and the boundary between the body side 42 and the body corner 43 are prevented from appearing clearly along the axial direction. When these parts are connected smoothly, the body corner part 43 has a cross-sectional shape that is rounded into an arc with a relatively large radius of curvature relative to the major axis and minor axis. The cross-sectional shape of the body corner portion 43 which is rounded into an arc shape is the main surface side circular arc portion 43a extending from the diagonal position of the body corner portion 43 toward the body main surface portion 41, and the body corner portion 43. The radius of curvature of the main surface side circular arc portion 43a at the maximum body diameter portion of the body portion 4 is Ra, and the radius of curvature of the same side surface side circular arc portion 43b is It is shaped so that the relationship expressed as 0.65×Rb≦Ra≦1.15×Rb holds, where Rb is 0.65×Rb≦Ra≦1.15×Rb.

According to this embodiment, the body corner portion 43 has a long axis and a short axis at the maximum body diameter portion that comes into contact with an adjacent container 1 on a filling line or when transported in a boxed state. By being rounded into an arc shape with a relatively large radius of curvature, the lateral rigidity of the portion can be increased. Further, when blow molding the container 1, in many cases, a blow mold is used that has one end fixed to a support shaft and opens and closes in a fan shape, and a parting line is arranged on the body corner portion 43. At this time, if the body corner portion 43 has an arc shape with a large radius of curvature, there is a risk that problems such as the edge of the mold rubbing the body corner portion 43 when the mold is opened may occur. In this embodiment, by making the cross-sectional shape of the body corner portion 43 as described above and arranging the parting line along the diagonal position, such a shape can be achieved without impairing the lateral rigidity. It is also possible to effectively avoid problems.

Furthermore, in this embodiment, the rectangular cross section of the body part 4 is designed to have a relatively large radius of curvature with respect to the major axis and the minor axis, and to increase the lateral rigidity by rounding the body part corner part 43 into an arc shape. It is preferable to increase the ratio of the trunk corner portion 43 to the entire body portion 4 while maintaining the surface shape, so that the planar area becomes smaller. More specifically, in the maximum body diameter portion of the body portion 4, the length L1 along the circumferential direction of the body main surface portion 41 is 30.4 to 61.8% of the major axis D1 of the body portion 4, It is preferable that the length L2 of the trunk side surface portion 42 along the circumferential direction is 17.8 to 49.5% of the minor axis D2 of the trunk portion 4, and the length L2 of the trunk side portion 42 is preferably 17.8% to 49.5% of the short axis D2 of the trunk portion 4. Even if there is, it is preferable that the same is true.

In the illustrated example, when focusing on a longitudinal section including the central axis C along the circumferential center of the trunk side portion 42 (see FIG. 8), the lower end portion of the shoulder portion 3 that continues to the trunk portion 4 has a vertical cross-sectional shape. is formed to include a lower end side circular arc portion 32a formed in an arc shape with a constant radius of curvature. In this embodiment, the boundary between the trunk 4 and the shoulder 3 is defined based on the region where the radius of curvature changes toward the trunk 4 in this longitudinal cross-sectional shape, and the central axis C including the region is defined. It is assumed that the body portion 4 and the shoulder portion 3 are divided by a plane perpendicular to (corresponding to a plane including the AA end face shown in FIG. 5). Similarly, the upper end portion of the bottom portion 5 connected to the body portion 4 includes an upper end side circular arc portion 52a having a vertical cross-sectional shape formed in an arc shape with a constant radius of curvature. The boundary between the body part 4 and the bottom part 5 is defined based on the part where the radius of curvature changes toward 4. (equivalent to) into a body portion 4 and a bottom portion 5.

As in the illustrated example, when the shoulder side end portion of the body portion 4 is the maximum body diameter portion and is continuous to the shoulder portion 3, the principal surface side circular arc portion 43a at the maximum body diameter portion When the smaller radius of curvature is Rmin between the radius of curvature Ra and the radius of curvature Rb of the side surface arc portion 43b, and the radius of curvature of the lower end side surface arc portion 32a is Rd, 2.3×Rmin≦Rd≦ It is preferable that the relationship expressed by 2.7×Rmin holds true.

By doing so, it is possible to further increase the lateral rigidity at the maximum body diameter portion, and in particular, when a lateral impact is applied to the body side surface portion 42, the maximum body diameter portion It is deformed so as to flex along with the surrounding parts and the load is dispersed, thereby making it possible to suppress the maximum body diameter part from collapsing. Furthermore, even if the maximum body diameter portion is crushed, it is possible to exert a restoring force to return to the original shape when the load is removed. For example, in a filling line, the container 1 can be transported so that its major diameter direction is along the feeding direction to prevent the container 1 from falling over. The containers 1 are pressed against each other from the sides of the body side portions 42. Therefore, when a lateral impact is applied to the body side surface 42, the above effect is particularly effective in suppressing deformation of the container 1 in the filling line. be.

Furthermore, in order to more effectively exhibit the above-mentioned effects, a longitudinal section including the central axis C along the diagonal position of the trunk corner portion 43 (including the central axis C and facing each other) is required. In a cross section taken along a plane passing through each diagonal position of the body corner portion 43 (see FIG. 9), the vertical cross-sectional shape of the lower end of the shoulder portion 3 that is continuous with the body portion 4 includes the lower end side corner arc portion 33a. , when the radius of curvature of the lower end side corner arc portion 33a is Re, the relationship expressed by 1.2×Rmin≦Re≦1.7×Rmin holds between the radius of curvature Rmin and the above-mentioned radius of curvature. preferable.

In addition, the shoulder portion 3 connecting the mouth portion 2 and the body portion 4 has a cross-sectional shape that extends from the mouth portion 2 side toward the body portion 4 side (the cross-sectional shape of the mouth portion 2 (a circular cross-sectional shape). The cross-sectional shape of the body 4 changes continuously from the cross-sectional shape of the body 4. At this time, the range in which the cross-sectional shape of the shoulder part 3 is circular is made as large as possible, and a part of the body main surface part 41 side gradually becomes flat (see FIG. 7), and then, It is preferable that the cross-sectional shape of the body section 4 gradually changes to become flat, with a portion of the body side surface section 42 side gradually changing to the shape of the cross section of the body section 4.
In addition, in FIG. 7, the cross-sectional shape is assumed that a part of the body main surface 41 side does not change to become flat and that the circular shape is maintained even on the body main surface 41 side. is shown by a two-dot chain line.

By doing so, the above effects can be more effectively exhibited. For this purpose, in a longitudinal section including the center axis C along the circumferential center of the body side section 42, the longitudinal section shape of the mouth section 2 side excluding the lower end side arcuate portion 32a of the shoulder section 3 must be an upper end side arcuate section. In the longitudinal section including the center axis C along the diagonal position of the body corner section 43, the vertical section shape on the mouth section 2 side excluding the lower end corner arc section 33a of the shoulder section 3 is the upper end corner. Including the circular arc part 33b, the upper end side circular arc part 32b extends from the mouth part 2 side to near the center in the height direction of the shoulder part 3 and is connected to the lower end side side circular arc part 32a, and the upper end side corner circular arc part 33b extends from the mouth portion 2 side beyond the central portion in the height direction of the shoulder portion 3 and is connected to the lower end side corner arc portion 33a, and is equal to the radius of curvature of the upper end side side arc portion 32b and the upper end side corner arc portion 33b. It is preferable that the shoulder portion 3 and the body portion 4 are smoothly connected so that the diameter of the shoulder portion 3 increases from the mouth portion 2 side toward the body portion 4 side so that the radius of curvature becomes equal. .

In this embodiment, a preform with a weight of 28 g is used to obtain a container shape as shown in the figure, and the length along the height direction excluding the mouth part 2 is approximately 226 mm, and the internal volume is approximately 720 ml. Container 1 was manufactured as described above, and its lateral rigidity was confirmed. Specifically, two containers 1 were filled with the contents and sealed, and with the side surfaces 42 of the bodies facing each other, they were sandwiched between two flat plates and a load was applied in parallel from the lateral direction. Even when a load of 200N was applied, no permanent deformation resulting in poor appearance was observed.

Although the present invention has been described above by showing preferred embodiments, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made within the scope of the present invention. Nor.

For example, in the illustrated example, two circumferential grooves 40 are provided in a constricted area at the center of the body 4 in the height direction so as to ensure rigidity when the area is gripped. However, the circumferential groove portion 40 may be omitted if necessary. Furthermore, a recess may be provided in the circumferential center of the trunk main surface 41 so as to overlap the circumferential groove 40 so that the fingertips that grip the container 1 can fit comfortably. Furthermore, in addition to the two circumferential grooves 40, an additional circumferential groove can be provided.

1 Container 2 Mouth 3 Shoulder 32a Lower end side arcuate portion 32b Upper end side arcuate portion 33a Lower end corner arcuate portion 33b Upper end corner arcuate portion 4 Body portion 41 Main surface portion of body portion 42 Side surface portion of body portion 43 Corner portion of body portion 43a Main surface side circular arc portion 43b Side side circular arc portion 5 Bottom portion

Claims (7)

A synthetic resin container comprising a mouth, a shoulder, a body, and a bottom,
The trunk includes a trunk main surface, a trunk side, and a trunk corner located between the trunk main surface and the trunk side,
The cross-sectional shape of the trunk corner portion is a main surface side circular arc portion extending from a diagonal position of the trunk corner portion toward the trunk main surface portion, and a main surface side circular arc portion extending from a diagonal position of the trunk corner portion to the trunk side surface portion. Including the side arc portion toward
At the maximum trunk diameter portion of the trunk,
When the major axis of the body is D1, the minor axis is D2, and the diagonal diameter is D3,
1.13≦D1/D2≦1.23, and 1.06≦D3/D1≦1.12
The relationship expressed by holds true,
When the radius of curvature of the main surface side circular arc portion is Ra and the curvature radius of the side surface side circular arc portion is Rb,
0.65×Rb≦Ra≦1.15×Rb
A synthetic resin container characterized by satisfying the relationship expressed by: In a longitudinal section including a central axis along the circumferential center of the body side surface portion, a vertical cross-sectional shape of a lower end portion of the shoulder portion continuous with the body portion includes a lower end side side circular arc portion,
The shoulder side end of the body portion is the maximum body diameter portion and is continuous with the shoulder portion,
The smaller radius of curvature of the main surface side circular arc portion Ra and the curvature radius Rb of the side surface side circular arc portion at the maximum body diameter portion is Rmin, and the radius of curvature of the lower end side side circular arc portion is Rd. When you do,
2.3×Rmin≦Rd≦2.7×Rmin
The synthetic resin container according to claim 1, wherein the relationship expressed by: In a longitudinal cross-section including a central axis along a diagonal position of the body corner portion, a vertical cross-sectional shape of a lower end portion of the shoulder portion continuous with the body portion includes a lower end corner circular arc portion,
When the radius of curvature of the lower end side corner circular arc portion is Re, between the radius of curvature Rmin,
1.2×Rmin≦Re≦1.7×Rmin
The synthetic resin container according to claim 2, wherein the following relationship holds true. In a longitudinal section including a central axis along the circumferential center of the body side portion, a longitudinal cross-sectional shape on the mouth side excluding the lower end side side circular arc portion of the shoulder portion includes an upper end side side circular arc portion,
In a longitudinal section including a central axis along a diagonal position of the body corner section, a longitudinal cross-sectional shape of the mouth section excluding the lower end corner arc section of the shoulder section includes an upper end corner arc section;
The upper end side side arcuate portion extends from the mouth side to near the center in the height direction of the shoulder portion and is connected to the lower end side side circular arc portion, and the upper end side corner circular arc portion extends from the mouth side to near the center in the height direction of the shoulder portion. Extending beyond the central part in the height direction of the shoulder part and connecting to the lower corner arc part, the radius of curvature of the upper end side arc part is equal to the radius of curvature of the upper corner arc part. 4. The synthetic resin container according to claim 3, wherein the shoulder portion has a diameter increasing from the mouth side toward the body side. A claim in which the maximum trunk diameter portion of the trunk portion is located on both the shoulder side and the bottom side, and the major axis, minor axis, and diagonal diameter of the trunk portion at each maximum trunk diameter portion are all equal. The synthetic resin container according to any one of items 1 to 4. The synthetic resin container according to any one of claims 1 to 4, wherein the major axis, minor axis, and diagonal diameter of the body become smaller toward a central portion in the height direction of the body. At the maximum trunk diameter portion of the trunk,
The length along the circumferential direction of the main surface of the trunk is 30.4 to 61.8% of the major axis D1 of the trunk,
The synthetic resin container according to any one of claims 1 to 4, wherein the length along the circumferential direction of the side surface of the body is 17.8 to 49.5% of the minor axis D2 of the body. .

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