JP4958326B2 - container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a new container. <P>SOLUTION: The container defines a storing space between its bottom part and barrel part 3 and forms a flange part 2 along an opening part. The container is made of a plastic. The lower edge 2a of the flange part 2 and the starting point P<SB>1</SB>of a curve intersect on a flat cross-section passing through the axis of the container. The outer edge 3c of the barrel part 3 and the end point P<SB>2</SB>of the curve intersect. A distance from the intersection P<SB>3</SB>of a line extended of the lower edge 2a and a line extended of the outer edge 3c to the end point P<SB>2</SB>is longer than a distance from the intersection P<SB>3</SB>to the starting point P<SB>1</SB>. This makes it possible to provide the new container. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a novel container.

  Currently, a large number of plastic containers are distributed in the market. Among plastic containers, a plastic container in which a flange is provided at an opening and a lid is thermocompression-bonded to the flange is used as a container for storing desserts, fermented milk, and the like.

  Many plastic containers are recycled and reused. However, if the weight per container is large, the cost for reuse increases and the impact on the environment also increases. Therefore, efforts have been made to reduce the weight of the container by reducing the weight per container. One method for reducing the weight of a container is to reduce the thickness of the container by thinning the components of the container.

  On the other hand, plastic containers need excellent drop impact resistance. If the container is inadvertently dropped during transportation of the container or the like, if the container is easily damaged, the original purpose of reliably containing the contents cannot be achieved.

  Also, a plastic container of the type that seals the lid needs excellent sealing properties. If the seal is easily peeled off during transportation of the container, the original purpose of reliably containing the contents cannot be achieved.

  However, when the plastic container is thinned, the drop impact resistance may be deteriorated. When the thickness of the constituent parts of the plastic container is reduced, the mechanical strength against bending stress is reduced. As a result, the drop impact resistance may be deteriorated.

  Further, when the plastic container is thinned, the sealing characteristics may be deteriorated. In a plastic container of a type in which a lid is sealed to the flange portion, if the flange portion is thinned for weight reduction, the flange portion may be swelled and it may be difficult to maintain the flatness of the flange portion. If the flatness of the flange portion cannot be maintained, even if a lid is thermocompression bonded to the flange portion, uniform thermocompression bonding cannot be performed, and the unsealing strength and sealing characteristics may be deteriorated.

  There has been no technical examination yet about the possibility that the drop impact resistance may be deteriorated and the sealing characteristics may be deteriorated when the plastic container is thinned. Development of a new container that solves these technical problems is desired.

  This invention is made | formed in view of such a subject, and it aims at providing a novel container.

In order to solve the above-described problems and achieve the object of the present invention, the container of the present invention is a container made of plastic, in which a housing space is formed by a bottom part and a body part, a flange part is formed in an opening, and One or a plurality of groove portions are formed in the flange portion on a cross section by a plane passing through the central axis, and the thickness of the flange portion is in the range of 0.5 to 1.2 mm. The thickness of the flange portion The ratio of the depth of the groove to the range is 0.2 to 0.5, the length of the flange is 2 mm or more, and the ratio of the total value of the width of the groove to the length of the flange Is in the range of 0.2 to 0.5 .

Here, although not necessarily limited, a barrel thin portion is formed in the barrel portion, and the thickness of the barrel thin portion is in a range of 0.2 mm or more and less than 0.6 mm, and the manufacturing method of the container is The injection molding method is preferred. Although not limited, the plastic is preferably polyethylene, polypropylene, or polystyrene.

  The present invention has the following effects.

In the present invention, a housing space is formed by a bottom portion and a body portion, a flange portion is formed in an opening portion, and in a container made of plastic, the flange portion has 1 or 2 on a cross section by a plane passing through the central axis of the container. A plurality of groove portions are formed , the thickness of the flange portion is in the range of 0.5 to 1.2 mm, and the ratio of the depth of the groove portion to the thickness of the flange portion is 0.2 to 0.5. Since the length of the flange portion is 2 mm or more and the ratio of the total width of the groove portion to the length of the flange portion is in the range of 0.2 to 0.5, A container can be provided.

Hereinafter, the best mode for carrying out the present invention will be described.
First, the best mode for carrying out the first aspect of the invention will be described.

  The basic configuration of the container of the present invention will be described. FIG. 1 is a plan view (A), a front view (B), and a bottom view (C) of an example of a container. The container 1 includes a body portion 3, a flange portion 2, a bottom portion 4, and a thread foot 5.

The body portion 3 forms the side wall of the container 1.
A flange portion 2 is formed in the opening 9 of the container 1. The flange portion 2 is made of a disk having an inner circumference circle and an outer circumference circle, and the inside of the inner circumference circle is a space. The inner circumference of the flange portion 2 and the upper end of the body portion 3 are integrated.

  A lid (not shown) is formed on the flange portion 2. The lid is sealed to the flange portion 2. Examples of the sealing method include thermocompression bonding, ultrasonic sealing, and heat fusion.

  A bottom 4 is formed at the bottom of the container 1. The bottom part 4 has a disk shape having a gentle convex part at the center. The outer periphery of the bottom part 4 is integrated with the lower end of the body part 3. A housing space 8 is formed by the bottom 4 and the body 3.

  A thread leg 5 is formed at the lowermost end of the container 1. The thread foot 5 has a substantially cylindrical shape. The upper end of the thread foot 5 is integrated with the outer periphery of the bottom portion 4. The container 1 does not have to have the thread foot 5.

  As shown in FIG. 1B, a central axis 7 exists in the center of the container 1 in the vertical direction. As shown in FIGS. 1A and 1B, the central shaft 7 is a rotationally symmetric axis of the body portion 3, the flange portion 2, the bottom portion 4, and the thread foot 5.

Outside diameter [Phi ₁ of the upper end of the container 1 is preferably in the range of 50 to 200 mm.
The shape of the container 1 is not limited to a substantially truncated cone as shown in FIG. In addition, various shapes such as a substantially truncated pyramid and a modified shape can be adopted.

  The container 1 is made of plastic. As the plastic, thermoplastic resins such as polyethylene, polypropylene, and polystyrene can be employed.

  As a manufacturing method of the container 1, injection molding, vacuum molding, blow molding, injection blow molding, or the like can be employed.

  When the container 1 is injection molded, L / T is preferably in the range of 270 or less. When L / T is 270 or less, there are advantages that molding becomes easy and generation of waviness of the flange can be prevented.

  Specific examples and comparative examples of the container 1 of the present invention will be described. FIG. 2 is a cross-sectional view showing an example and a comparative example in the upper part of the container 1. Here, the cross-sectional view is a cross-sectional view taken along a plane passing through the central axis 7 of the container 1.

Example 1

The thickness _{T 1} of the flange portion 2 is 0.7 mm, the length _{L 1} is 3.6 mm. The thickness _{T 2} of the body thick part 3a of the body portion 3 is 0.6 mm, the length _{L 3} is 4.6 mm. The thickness T3 of the body thin portion 3b of the body portion ₃ is 0.3 mm. The inclination angle θ ₁ of the body part 3 is 6 °.

Extension of the outer edge 3c of the extension and the body portion 3 of the lower side 2a of the flange 2 intersect, forms an intersection P _3.

Radius _{R 2} of arcuate is 0.5 mm, the starting point _{P 1} of the arc is intersects with the lower side 2a. At the starting point P _1, the arc tangent coincides with the lower side 2a.

Radius _{R 3} of the arc is 1.6 mm, the end point _{P 2} of the circular arc intersects with the outer edge 3c. At the end point P _2, the arc tangent coincides with the outer edge 3c. Arc of the circular arc and the radius R ₃ of the radius R ₂ is intersect to form a contact. In this contact, the arc tangent of the arc tangent and the radius R ₃ of the radius R ₂ is consistent.

The distance L ₂ between the start point P ₁ and the intersection point P ₃ is 0.6 mm, and the distance L ₄ between the end point P ₂ and the intersection point P ₃ is 1.28 mm. The distance _{L 4} is longer than the distance _{L 2.}

Comparative Example 1

Radius _{R 1} of the arc is 0.5 mm. Start point P ₁ of the arc is intersects with the lower side 2a. At the starting point P _1, the arc tangent coincides with the lower side 2a. The end point P ₂ of the circular arc intersects with the outer edge 3c. At the end point P _2, the arc tangent coincides with the outer edge 3c. The rest is the same as in the first embodiment.

  The containers of Example 1 and Comparative Example 1 were tested for drop impact resistance. The drop impact resistance test was carried out by dropping a container filled with water up to a specified amount and sealing it so that the flange part hits vertically from a height of 80 cm and a method where the bottom face hits horizontally.

As a result of the drop impact resistance test, the occurrence of cracks 6 was observed in the container of Comparative Example 1. Crack 6 has occurred in the position of the end point P _2. The reason for the occurrence of the crack 6 is considered as follows. Processing line is present at the position of the end point P _2. Therefore, in the drop impact resistance test, the impact force concentrates on the processing line due to stress concentration. As a result, it is considered that the crack 6 is generated from the processed line.

As a result of a drop impact resistance test, no crack was observed in the container of Example 1. The reason why the crack did not occur is considered as follows. The position of the processing line (end point P ₂ ) has moved toward the bottom of the container as compared with Comparative Example 1. Therefore, it is considered that the impact force is dispersed and relaxed in the drop impact resistance test.

The dimension of the flange part 2 and the trunk | drum 3 is not limited to the value of the said Example.
The thickness _{T 1} of the flange portion 2 is preferably in the range of 0.5 to 1.2 mm. When a thick T ₁ is 0.5mm or more, there is an advantage that the flange stiffness when peeling the seal is maintained. If the thickness T ₁ is is 1.2mm or less, there is an advantage that it is possible to maintain the formability.

It is preferred length _{L 1} of the flange portion 2 is 2mm or more. If the length L ₁ is at 2mm or more, there is an advantage that a seal easily.

The thickness _{T 2} of the DoAtsu walled portion 3a is preferably in the range of 0.3 to 1.0 mm.
The length _{L 3} of DoAtsu walled portion 3a is preferably in the range of 2 to 10 mm.

Cylinder thickness _{T 3} of the thin-walled portion 3b is 0.2mm or more, and preferably in the range of less than 0.6 mm. If the thickness _{T 3} is at 0.2mm or more, there is an advantage that molding is easy. If the thickness T ₃ is less than 0.6 mm, there is the advantage that it is lighter containers by weight.

It is preferable that the inclination angle θ ₁ of the body portion 3 is in the range of 2 to 10 °. When the angle θ ₁ is 2 ° or more, there are advantages that the stack height can be reduced and the molding becomes easy.

Radius _{R 2} of the circular arc is preferably in the range of 0.3 to 1.0 mm. The radius R ₂ is a 0.3mm or more, there is an advantage that it is possible to avoid stress concentration. The radius _{R 2} is a 1.0mm or less, there is an advantage that the seal is likely to. Start point P ₁ of the arc is intersects with the lower side 2a. At the starting point P _1, the arc tangent coincides with the lower side 2a.

The radius R ₃ of the arc is preferably larger than the radius R _{2 and} within a range of 3 mm or less. The radius R ₃ is larger than the radius R _2, can be advantageously lowered position of the end point P ₂ towards the bottom. The radius R ₃ is a 3mm or less, there is an advantage that the occurrence of cracking can be prevented. The end point P ₂ of the circular arc intersects with the outer edge 3c. At the end point P _2, the arc tangent coincides with the outer edge 3c. Arc of the circular arc and the radius R ₃ of the radius R ₂ is intersect to form a contact. In this contact, the arc tangent of the arc tangent and the radius R ₃ of the radius R ₂ is consistent.

The curve existing between the lower side 2a and the outer side 3c is not limited to the circle. In addition, a quadratic curve, a cubic curve, a cycloid curve, etc. are employable as a curve.
The total number of curves is preferably in the range of 2-4.

Start point P ₁ of the curve that exists in most upwardly intersects with the lower side 2a. At the starting point P _1, the tangent of the curve coincides with the lower side 2a. Adjacent curves intersect to form a contact. At this point of contact, the tangents of adjacent curves coincide. End point P ₂ of the curve that most existing downward intersects with the outer edge 3c. At the end point P _2, the tangent of the curve coincides with the outer edge 3c.

Distance _{L 2} starting _{P 1} and the intersection _{P 3} is preferably in the range of 0.4 to 1.0 mm. If the distance _{L 2} is at 0.4mm or more, there is an advantage that the occurrence of cracking can be prevented. If the distance L ₂ is at 1.0mm or less, there is an advantage that the area corresponding to the cell plate can be secured.

The distance L ₄ between the end point P ₂ and the intersection point P ₃ is preferably larger than the distance L _{2 and} within a range of 3.0 mm or less. And the distance L ₄ is greater than the distance L _2, there is an advantage that the position of the end point P ₂ can be lowered towards the bottom. When the distance _{L 4} is a 3.0mm or less, there is an advantage that the occurrence of cracking can be prevented.
The distance _{L 4} is longer than the distance _{L 2.}

  From the above, according to the best mode for carrying out the present invention, a container having excellent drop impact resistance can be provided.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, the best mode for carrying out the second aspect of the invention will be described.

  The basic configuration of the container of the present invention will be described. FIG. 1 is a plan view (A), a front view (B), and a bottom view (C) of an example of a container. The container 1 includes a body portion 3, a flange portion 2, a bottom portion 4, and a thread foot 5. The trunk | drum 3, the flange part 2, the bottom part 4, and the thread | yarn leg 5 are the same as that of the best form for implementing 1st invention. The lid is also the same as the best mode for carrying out the first invention.

A preferable range of the outer diameter Φ ₁ of the upper end of the container 1 is the same as the best mode for carrying out the first invention. The shape, material, manufacturing method of the container 1 and the value of L / T in the case of injection molding are the same as in the best mode for carrying out the first invention.

  Specific examples and comparative examples of the container 1 of the present invention will be described. FIG. 3 is a cross-sectional view showing an example and a comparative example in the upper part of the container. Here, the cross-sectional view is a cross-sectional view taken along a plane passing through the central axis 7 of the container 1.

Example 2

The thickness _{T 3} of the trunk portion 3 is 0.3 mm. In Example 2, the thick part 3a of Example 1 does not exist. Other conditions are the same as those in the first embodiment.

Comparative Example 2

Radius _{R 1} of the arc is 0.5 mm. Start point P ₁ of the arc is intersects with the lower side 2a. At the starting point P _1, the arc tangent coincides with the lower side 2a. The end point P ₂ of the circular arc intersects with the outer edge 3c. At the end point P _2, the arc tangent coincides with the outer edge 3c.
Other than this, the second embodiment is the same as the second embodiment.

  The containers of Example 2 and Comparative Example 2 were tested for drop impact resistance. The drop impact resistance test method is the same as the test method of Example 1 and Comparative Example 1 above.

As a result of a drop impact resistance test, the occurrence of cracks 6 was observed in the container of Comparative Example 2. Crack 6 has occurred in the position of the end point P _2. The reason for the occurrence of the crack 6 is considered as follows. Processing line is present at the position of the end point P _2. Therefore, in the drop impact resistance test, the impact force concentrates on the processing line due to stress concentration. As a result, it is considered that the crack 6 is generated from the processed line.

As a result of a drop impact resistance test, no cracks were observed in the container of Example 2. The reason why the crack did not occur is considered as follows. The position of the processing line (end point P ₂ ) has moved toward the bottom of the container as compared with Comparative Example 1. Therefore, it is considered that the impact force is dispersed and relaxed in the drop impact resistance test.

Barrel thickness _{T 3} of 3 0.2mm or more, and preferably in the range of less than 0.6 mm. If the thickness _{T 3} is at 0.2mm or more, there is an advantage that it can be molded. If the thickness T ₃ is less than 0.6 mm, there is the advantage that it is lighter containers by weight.

The dimension of the flange part 2 and the trunk | drum 3 is not limited to the value of the said Example 2. FIG.
The preferred ranges for the thickness T ₁ and length L _{1 of} the flange portion 2, the inclination angle θ ₁ of the body portion 3, the radius R _{2 of} the arc, and the radius R ₃ of the arc are the best for carrying out the first invention. It is the same as the form.

Start point P ₁ of the arc intersects with the lower side 2a. At the starting point P _1, the arc tangent coincides with the lower side 2a. End point P ₂ of the circular arc intersects with the outer edge 3c. At the end point P _2, the arc tangent coincides with the outer edge 3c. Arc of the circular arc and the radius R ₃ of the radius R ₂ is intersect to form a contact. In this contact, the arc tangent of the arc tangent and the radius R ₃ of the radius R ₂ is consistent.

  The types of curves existing between the lower side 2a and the outer side 3c and the total number of curves are the same as in the best mode for carrying out the first invention.

Start point P ₁ of the curve that exists in most upwardly intersects with the lower side 2a. At the starting point P _1, the tangent of the curve coincides with the lower side 2a. Adjacent curves intersect to form a contact. At this point of contact, the tangents of adjacent curves coincide. End point P ₂ of the curve that most existing downward intersects with the outer edge 3c. At the end point P _2, the tangent of the curve coincides with the outer edge 3c.

A preferred range of the start point P ₁ and the distance L ₂ intersection P _3, and the end point P ₂ and the distance of the intersection point P ₃ L ₄ are the same as the best mode for carrying out the first invention. The distance _{L 4} is longer than the distance _{L 2.}

  From the above, according to the best mode for carrying out the present invention, a container having excellent drop impact resistance can be provided.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, the best mode for carrying out the third aspect of the invention will be described.

  The basic configuration of the container of the present invention will be described. FIG. 1 is a plan view (A), a front view (B), and a bottom view (C) of an example of a container. The container 1 includes a body portion 3, a flange portion 2, a bottom portion 4, and a thread foot 5. The trunk | drum 3, the flange part 2, the bottom part 4, and the thread | yarn leg 5 are the same as that of the best form for implementing 1st invention. The lid is also the same as the best mode for carrying out the first invention.

A preferable range of the outer diameter Φ ₁ of the upper end of the container 1 is the same as the best mode for carrying out the first invention. The shape, material, manufacturing method of the container 1 and the value of L / T in the case of injection molding are the same as in the best mode for carrying out the first invention.

  Specific examples and comparative examples of the container 1 of the present invention will be described. FIG. 4 is a cross-sectional view showing an example and a comparative example in the lower part of the container. Here, the cross-sectional view is a cross-sectional view taken along a plane passing through the central axis 7 of the container 1.

Example 3

The inner side of the trunk portion 3 and the bottom portion 4 is connected by two curves. Inner sides of the bottom portion 4 is connected to the arc having a radius R _7. The arc having the radius R ₇ and the inner side of the body 3 are connected to the arc having the radius R ₈ . Radius _{R 8} is greater than the radius _{R 7.}

The outer side of the bottom part 4 and the left side (on the drawing) of the thread foot 5 are connected by two curves. Left side of Itoashi 5 is connected to the arc having a radius R _9. Perimeter of the circular arc and the bottom 4 of the radius R ₉ is connected to the arc having a radius R _10. Radius _{R 10} is larger than the radius _{R 9.}

Comparative Example 3

Barrel 3 and the bottom 4, each inner side is connected to the arc having a radius R _5. Left side of the perimeter and Itoashi 5 of the bottom 4 (the drawing) is connected to the arc having a radius R _6. Other conditions are the same as in the third embodiment.

The container of Example 3 is superior to the container of Comparative Example 3 in drop impact resistance.
A processing line exists at a connection point between the inner side of the body portion 3 and the arc. In Example 3, the position of the processing line has moved to the upper side of the container as compared with Comparative Example 3. Therefore, it is considered that the impact force generated by the drop of the container is dispersed and alleviated.

  A machining line exists at the connection point between the outer edge of the bottom 4 and the arc. In Example 3, the position of the processing line is moved toward the center of the container as compared with Comparative Example 3. Therefore, it is considered that the impact force generated by the drop of the container is dispersed and alleviated.

The method of connecting the two arcs is not limited to the third embodiment. An arc larger than the radius R ₇ may be connected to both sides of the arc having the radius R _{7, and} an arc larger than the radius R ₇ is located at a position opposite to that in the third embodiment with respect to the arc having the radius R _7. You may connect. As a result, the same effect as in the third embodiment can be obtained.

An arc larger than the radius R ₉ may be connected to both sides of the arc having the radius R _{9, and} an arc larger than the radius R ₉ is located at a position opposite to that in the third embodiment with respect to the arc having the radius R _9. You may connect. As a result, the same effect as in the third embodiment can be obtained.

  The curved line existing between the inner side of the body part 3 and the inner side of the bottom part 4 and the music existing between the outer side of the bottom part 4 and the left side of the thread foot 5 (on the drawing) are limited to the aforementioned circles. It is not something. In addition, a quadratic curve, a cubic curve, a cycloid curve, etc. are employable as a curve. The total number of curves is preferably in the range of 2-4.

  From the above, according to the best mode for carrying out the present invention, a container having excellent drop impact resistance can be provided.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

  Next, the best mode for carrying out the fourth aspect of the invention will be described.

  The basic configuration of the container of the present invention will be described. FIG. 1 is a plan view (A), a front view (B), and a bottom view (C) of an example of a container. The container 1 includes a body portion 3, a flange portion 2, a bottom portion 4, and a thread foot 5. The trunk | drum 3, the flange part 2, the bottom part 4, and the thread | yarn leg 5 are the same as that of the best form for implementing 1st invention. The lid is also the same as the best mode for carrying out the first invention.

A preferable range of the outer diameter Φ ₁ of the upper end of the container 1 is the same as the best mode for carrying out the first invention. The shape, material, manufacturing method of the container 1 and the value of L / T in the case of injection molding are the same as in the best mode for carrying out the first invention.

  Specific examples and comparative examples of the container 1 of the present invention will be described. FIG. 5 is a cross-sectional view showing an embodiment of the flange portion of the container. Here, the cross-sectional view is a cross-sectional view taken along a plane passing through the central axis 7 of the container 1.

Example 4

The thickness _{T 1} of the flange portion 2 is 0.7 mm, the length _{L 1} is 3.6 mm.
Two grooves 2 b are formed on the lower side 2 a of the flange 2. The shape of the groove 2b is a semicircle. Depth _{T 2} of the groove 2b is 0.3mm. The ratio T ₂ / T ₁ of the depth T ₂ of the groove 2b to the thickness T ₁ of the flange 2 is 0.43. Width _{W 1} of the groove 2b is 0.5mm. The ratio (2 × W ₁ ) / L ₁ of the total value of the width W ₁ of the groove 2b to the length L ₁ of the flange 2 is 0.29.

Example 5

  The shape of the groove 2b is substantially rectangular. Other conditions are the same as in Example 4.

Comparative Example 4

  In Comparative Example 4 (not shown), the groove 2b does not exist. Other conditions are the same as in Example 4.

  For the containers of Examples 4 and 5 and Comparative Example 4, the flatness of the flange portion 2 was visually observed. In addition, a seal characteristic test was conducted. The seal characteristic test was performed by attaching a push-pull gauge to the sealing material after sealing and measuring the opening strength.

  As a result of observing the flatness of the flange portion 2, the occurrence of waviness was observed in the flange portion 2 of the container of Comparative Example 4. Generation | occurrence | production of the wave | undulation was not recognized in the flange part 2 of the container of Examples 4 and 5, and flatness was ensured.

  As a result of testing the sealing characteristics, the sealing characteristics of the containers of Examples 4 and 5 were superior to the sealing characteristics of the container of Comparative Example 4. The reason for this is that the occurrence of waviness was observed in the flange portion 2 of the container of Comparative Example 4, whereas the occurrence of waviness was not observed in the flange portion 2 of the containers of Examples 4 and 5, and the flatness This is probably because of

The containers of Examples 4 and 5 were superior in drop impact resistance compared to the container of Comparative Example 4.
In the flange portion 2 of the containers of Examples 4 and 5, the groove portion 2b is present as compared with the container of Comparative Example 4. The groove portion 2b has a thin flange portion 2 and is easily deformed flexibly with respect to bending force. Therefore, in the drop impact resistance test, even if the impact force at the time of grounding is transmitted to the flange portion 2, a part of the impact force is absorbed by the bending deformation of the flange portion 2, and the impact force to the trunk portion 3 is compared. It is considered to be smaller than Example 4.

The dimension of the flange part 2 and the groove part 2b is not limited to the value of the said Example.
The preferable ranges of the thickness T ₁ and the length L ₁ of the flange portion 2 are the same as in the best mode for carrying out the first invention.

The groove 2b is not limited to being provided on the lower side 2a of the flange 2. In addition, it may be provided on the upper side 2c, or may be provided on both the upper side 2c and the lower side 2a.
The number of grooves 2b is preferably in the range of 1 to 3.

The groove portion 2b is preferably formed in a ring shape along the flange portion 2. By forming the groove 2b in a ring shape, the flatness of the flange 2 is improved.
As the shape of the groove 2b, a semicircle, a semi-ellipse, a substantially polygon or the like can be adopted.

The ratio T ₂ / T ₁ of the depth T ₂ of the groove 2b to the thickness T ₁ of the flange 2 is preferably in the range of 0.2 to 0.5.

The ratio of the sum of the width _{W n} of the groove portion 2b to the length _{L 1} of the flange portion 2 (the number × _W n) / _{L 1} is preferably in the range of 0.2 to 0.5.

  From the above, according to the best mode for carrying out the present invention, it is possible to provide a container having excellent flatness and sealing characteristics.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

It is the top view (A), front view (B), and bottom view (C) of a container. It is sectional drawing which shows the Example and comparative example in the upper part of a container. It is sectional drawing which shows the Example and comparative example in the upper part of a container. It is sectional drawing which shows the Example and comparative example in the lower part of a container. It is sectional drawing which shows the Example in the flange part of a container.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Flange part, 2a ... Lower side, 2b ... Groove part, 2c ... Upper side, 3 ... Body part, 3a ... Body thick part, 3b ... Body thin part, 3c ... Outer side, 4 ... Bottom, 4a ... Bottom flat plate, 4b ... Bottom convex part, 5 ... Yarn foot, 6 ... Crack, 7 ... Center axis, 8 ... Storage space, 9 ... Opening , P ₁ ... start point, P ₂ ... end point, P ₃ ... intersection

Claims (3)

A storage space is formed by the bottom and the body,
Form a flange in the opening,
In containers made of plastic,
On the cross section by a plane passing through the central axis of the container, the flange portion is formed with one or a plurality of grooves ,
The flange portion has a thickness in the range of 0.5 to 1.2 mm,
The ratio of the depth of the groove to the thickness of the flange is in the range of 0.2 to 0.5,
The length of the flange portion is 2 mm or more,
The ratio of the total value of the width | variety of the said groove part with respect to the length of the said flange part exists in the range of 0.2-0.5, The container characterized by the above-mentioned. A body thin part is formed in the body,
The thickness of the thin-walled portion is in the range of 0.2 mm or more and less than 0.6 mm,
2. The container according to claim 1, wherein the method for producing the container is an injection molding method. The container according to claim 1 or 2, wherein the plastic is polyethylene, polypropylene, or polystyrene.

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