Resin lids and containers with lids

Abstract

To provide a container with a lid which can suppress liquid leakage caused by a step cavity with a simple constitution.SOLUTION: A container with a lid is composed of a paper container 100 and a resin lid 1. The paper container 1 has a paper container fitting part 103 provided in a paper container opening 104, and has a step 105 on a container body surface 102. The resin lid 1 has a lid top surface 10, and a lid fitting part 30 which is provided in the periphery of the lid top surface 10 and is fit into the paper container fitting part 103. The lid fitting part 30 has a lid fitting part outer wall 31, a lid fitting part top part 32, and a lid fitting part inner wall 33. The lid fitting part inner wall 33 faces the body part 102 of the paper container. An under projection 36 projecting in a circumferential outer direction is provided in the lid fitting part inner wall 33.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lidded container comprising a container and a lid, and more particularly to a lidded container having a step on the body or flange of the container. [Background technology]

[0002] Containers for beverages or liquid foods are preferably provided with lids. By devising a fitting structure between the lid and the container, leakage of liquid during transportation can be suppressed (for example, Patent Document 1).

[0003] Recently, paper containers have become popular from an environmentally friendly perspective. A paper container has a bottom, a body extending from the bottom, and a flange formed at the top end of the body. An opening is formed at the top end of the body. The flange is often formed with an outward curl. A lid is fitted onto the flange.

[0004] In the case of circular containers, the body is generally shaped like an inverted truncated cone. The inverted truncated cone shape is formed by overlapping both ends of a roughly fan-shaped paper blank. During this manufacturing process, minute steps are generated in the body and flange of the container, resulting in voids.

[0005] As a result, even if the adhesion of the fitting structure between the lid and the container is improved, there is a limit to how much liquid leakage can be prevented from the gap between the lid and the container. In particular, in recent years, containers with lids have been widely used for delivery and takeout of products, so the risk of the container tipping over needs to be considered. If the container is returned to its original position within a few seconds after tipping over, overall liquid leakage can be prevented, but liquid leakage from the gap between the lid and the container can still occur.

[0006] To prevent liquid leakage from the gap between the steps, it has been considered to place a buffer material made of a foam material inside the lid fitting portion (for example, Patent Document 2). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 2004-001892 [Patent Document 2] Japanese Patent Application Publication No. 2019-077475 Summary of the Invention [Problem to be solved by the invention]

[0008] The liquid leakage prevention structure described in Patent Document 2 requires a separate cushioning material made of a foam material as an essential component. Generally speaking, the more components there are, the more manufacturing steps and costs there are, which is undesirable.

[0009] Furthermore, in the liquid leakage prevention structure described in Patent Document 2, the buffer material is provided on the back of the top part of the fitting part, so there remains a risk of liquid leakage from the gap at the step in the upper part of the body part.

[0010] Therefore, it is necessary to suppress the liquid leakage from the step gap by a means different from the liquid leakage suppression structure described in Patent Document 2.

[0011] The present invention is intended to solve the above-mentioned problems, and has an object to provide a lidded container that can suppress liquid leakage caused by step gaps with a simple configuration. [Means for solving the problem]

[0012] To achieve the above object, the resin lid of the present invention includes a lid top surface and a lid fitting portion provided around the lid top surface and fitting with a container fitting portion provided at a container opening. The lid fitting portion has a lid fitting portion outer wall, a lid fitting portion top portion, and a lid fitting portion inner wall. The lid fitting portion inner wall faces the body of the container. The lid fitting portion inner wall is provided with an under-projection that protrudes circumferentially outward.

[0013] The under projections are tightly fitted to the body of the container while deforming, and deform to fill gaps in the container steps, thereby preventing liquid leakage caused by gaps in the steps.

[0014] In the above invention, preferably, the thickness of the under projection is thinner than the thickness of the top of the lid fitting portion.

[0015] The thin wall of the under projection makes it less rigid and more likely to deform.

[0016] In the above invention, preferably, the under projection has a curved shape in vertical cross section.

[0017] The curved shape of the under projection makes it less rigid and more likely to deform.

[0018] In the above invention, preferably, the taper angle of the inner wall of the lid fitting portion is equal to the taper angle of the paper container, and the inner wall of the lid fitting portion is provided with a step protrusion protruding circumferentially outward above the under protrusion.

[0019] The step protrusion presses against the body of the container, improving its sealing performance. Furthermore, by forming the step protrusion, the sheet is stretched to the step portion, further increasing the vertical distance, making the under-protrusion thinner. Furthermore, the step protrusion has higher rigidity than the under-protrusion, ensuring deformation of the under-protrusion.

[0020] In the above invention, preferably, the thickness of the under projection is thinner than the thickness of the step projection.

[0021] This makes the stepped projection more rigid than the under projection.

[0022] The lidded container of the present invention, which achieves the above object, comprises a paper container and a plastic lid. The paper container has a paper container fitting portion provided at the opening of the paper container and has a step on the container body surface. The plastic lid has a lid top surface and a lid fitting portion provided around the periphery of the lid top surface and fitting with the paper container fitting portion. The lid fitting portion has a lid fitting portion outer wall, a lid fitting portion top portion, and a lid fitting portion inner wall. The lid fitting portion inner wall faces the body of the paper container. The lid fitting portion inner wall has an under-projection that protrudes circumferentially outward.

[0023] The under projections are tightly fitted to the body of the container while deforming, and deform to fill gaps in the container steps, thereby preventing liquid leakage caused by gaps in the steps.

[0024] In the above invention, preferably, the under projection is provided at least in a part of the circumferential direction in correspondence with a step of the paper container.

[0025] The under projections may be provided all around the circumference, but if they are at least at positions corresponding to the steps, liquid leakage due to gaps caused by the steps can be suppressed.

[0026] In the above invention, the container with lid is preferably for hot beverages.

[0027] The under-projection flexibly deforms due to the heat of steam generated from the hot beverage.

[0028] In the above invention, the container with lid is preferably for use in a microwave oven.

[0029] When heated in the microwave, the under projections become flexible and deformed. [Effects of the Invention]

[0030] The lidded container of the present invention can suppress liquid leakage caused by step gaps with a simple structure. [Brief explanation of the drawings]

[0031] [Figure 1] Schematic diagram of a container with a lid [Figure 2] Schematic diagram of the lid [Figure 3] Detailed diagram of the lid [Figure 4] Schematic diagram of the fitting operation of the lid and container [Figure 5] Detailed explanatory diagram of the contact state between the inner wall of the lid fitting portion and the body of the container [Figure 6] Step rib operation diagram [Figure 7] Explanation of operation when container falls over [Figure 8] Variations [Figure 9] Variations [Figure 10] Examples of application other than round paper containers DETAILED DESCRIPTION OF THE INVENTION

[0032] ~Basic configuration~ 1 is a schematic diagram of a container with a lid. First, the basic structure will be explained. The container with a lid consists of a lid 1 and a container 100.

[0033] The container 100 is made of paper and is generally laminated. It comprises a bottom 101, a body 102, and a flange 103. The bottom 101 is circular in plan view. The body 102 is roughly in the shape of an inverted truncated cone in side view and stands upright from the bottom 101. The flange 103 is formed at the upper end of the body 102 and is curled outward from the periphery.

[0034] An opening 104 is formed at the upper end of the body 102. The lid 1 is fitted onto the flange 103 to close the opening 104.

[0035] The body 102 is formed by overlapping both ends of a roughly fan-shaped paper blank, which creates a step 105 between the body 102 and the flange 103.

[0036] The lid 1 is made of resin. For example, it is made of polypropylene. It may also be made of polyethylene, polyethylene terephthalate, polystyrene, or the like.

[0037] ~Lid composition~ Figure 2 is a schematic diagram of the lid, and Figure 3 is a detailed diagram of the lid.

[0038] The lid 1 is composed of a lid top surface 10 and a lid fitting portion 30. The lid fitting portion 30 is provided on the periphery of the lid top surface 10, and fits into a container fitting portion (flange portion 103) provided on the container opening 104.

[0039] The lid fitting portion 30 has a lid fitting portion outer wall 31, a lid fitting portion top portion 32, and a lid fitting portion inner wall 33. That is, the lid fitting portion outer wall 31 and the lid fitting portion inner wall 33 face each other, and the lid fitting portion outer wall 31 and the lid fitting portion inner wall 33 are continuous with the lid fitting portion top portion 32 at their upper ends, forming a generally gate-like shape and forming a fitting space 34 surrounded by the gate-like shape.

[0040] An under projection 36 is provided on the lower part of the lid fitting portion inner wall 33, and a step projection 37 is provided in the middle part of the lid fitting portion inner wall 33 above the under projection 36 (described in detail later).

[0041] The configuration of the lid top surface 10 will now be described. The lid top surface central portion 11 is located at the center of the lid top surface 10.

[0042] The stepped rib portion 12 is provided on the lid top surface 10 so as to be adjacent to the lid fitting portion inner wall 33. The stepped rib portion 12 consists of a width portion 13 and a height portion 14. The width portion 13 extends horizontally from the lower end of the lid fitting portion inner wall 33. The height portion 14 extends diagonally upward from the end of the width portion 13. The taper is preferably about 0 to 45 degrees.

[0043] Step rib portion 15 is provided on lid top surface 10 so as to be adjacent to step rib portion 12. Step rib portion 15 consists of width portion 16 and height portion 17. Width portion 16 extends horizontally from the upper end of height portion 14 of step rib portion 12. Height portion 17 extends diagonally upward from the end of width portion 16. The taper is preferably about 0 to 45 degrees.

[0044] Step rib portion 18 is provided on lid top surface 10 so as to be adjacent to step rib portion 15. Step rib portion 18 consists of a width portion (numbering omitted) and a height portion (numbering omitted). The width portion of step rib portion 18 extends horizontally from the upper end of height portion 17 of step rib portion 15. The height portion of step rib portion 18 extends downward from the end of the width portion of step rib portion 18 and is continuous with the peripheral edge of center portion 11 of the lid top surface.

[0045] Furthermore, a plurality of (five in the figure) stepped rib portions 19 that dig into the radial direction are provided at approximately equal intervals in the circumferential direction in the center portion 11 of the lid top surface.

[0046] ~Protrusion~ An under-projection 36 is provided on the lower part of the lid fitting portion inner wall 33, and a step-projection 37 is provided above the under-projection 36 in the middle part of the lid fitting portion inner wall 33. In the preferred example shown in the figure, one under-projection 36 and three step-projections 37 are provided, but the number is not limited thereto.

[0047] The under projection 36 is provided so as to protrude outward along the circumference. In the preferred example shown in the figure, it has a semi-elliptical shape in vertical cross section. For example, if the height of the lid fitting portion inner wall 33 is about 10 mm, it is preferable that the major axis diameter of the under projection 36 is about 1 to 3 mm and the minor axis diameter is about 0.5 to 1.2 mm. In addition to a semi-elliptical shape, a curved shape in vertical cross section, such as a semicircle or semi-oval, is preferable because it does not hinder the deformation of the under projection when the lid is fitted.

[0048] The step protrusion 37 is provided so as to protrude outward along the periphery. In the preferred example shown in the figure, it has a right-angled triangle shape in vertical cross section. The step protrusion 37 is formed so as to extend vertically downward from the upper end and horizontally from the lower end. For example, if the height of the lid fitting portion inner wall 33 is about 10 mm, the height of the step protrusion 37 is preferably about 1 to 2 mm and the width is preferably about 0.1 to 0.3 mm.

[0049] The stepped projection 37 may have any shape other than a triangle, as long as the stepped shape ensures adequate rigidity when the lid is fitted. It may also have a square shape, etc.

[0050] The above dimensions are merely examples to facilitate understanding of the invention, and the invention is not limited to these dimensions.

[0051] ~Thick~ Consider the thickness of the resin lid of the present invention. The following dimensions are examples to facilitate understanding of the invention, and are not limited to these dimensions. For example, a film with a thickness of 0.3 mm is formed.

[0052] The thickness of the lid fitting outer wall 31 is 0.17 to 0.21 mm, the thickness of the lid fitting top portion 32 is 0.25 to 0.27 mm, the thickness of the area on the upper part of the lid fitting inner wall 33 where no protrusions are formed is 0.21 to 0.24 mm, the thickness of the step protrusion 37 is 0.15 to 0.20 mm, and the thickness of the under protrusion 36 is 0.12 to 0.14 mm.

[0053] The thickness of the height portion 14 of the stepped rib portion 12 is 0.12 to 0.16 mm, and the thickness of the height portion 17 of the stepped rib portion 15 is 0.18 to 0.21 mm.

[0054] That is, the under projection 36 is the thinnest and is easily deformed due to its low rigidity.

[0055] Furthermore, by forming the step projection 37 in the middle of the inner wall 33 of the lid fitting portion, the sheet is stretched to the step portion, and the vertical distance is further increased, so that the under projection 36 can be reliably made thin.

[0056] ~Mating~ 4 is a schematic diagram showing the fitting operation of the lid 1 and the container 100. The container flange portion 103 is fitted into the fitting space 34 of the lid fitting portion 30. The lid fitting portion outer wall 31 is recessed inward to correspond to the shape of the container flange portion 103.

[0057] When fitted, the lid fitting portion inner wall 33 and the container body 102 face each other. In particular, it is preferable that the taper angle of the lid fitting portion inner wall 33 is equal to the taper angle of the paper container 102, and that the lid fitting portion inner wall 33 and the container body 102 come into contact as much as possible. This improves the sealing performance.

[0058] 5 is a detailed view of the state of contact between the lid fitting portion inner wall 33 and the container body portion 102 when fitted. The under projection 36 is provided so as to protrude outward along the periphery.

[0059] A reaction force acts on the container body 102. The under-projection 36 is easily deformed due to the combined effect of its curved shape and thin wall. The elasticity of the under-projection 36 further improves the sealing performance. In particular, the under-projection 36 deforms to fill the gap caused by the container step 105. This makes it possible to suppress liquid leakage caused by the gap caused by the step 105 with a simple configuration.

[0060] While the under-projection 36 is easily deformed, the stepped projection 37 has high rigidity (is less likely to be displaced) due to the synergistic effect of its right-angled triangular shape and relatively thick wall. The stepped projection 37 is provided so as to protrude outward along the periphery. The convex portion of the stepped projection 37 presses against the container body 102. The pressing force of the stepped projection 37 improves the sealing performance.

[0061] On the other hand, the stepped rib portion 12 functions as a rib (described in detail later). The stepped rib portion 12 has high rigidity (is less likely to be displaced) due to its rib function.

[0062] When the deformation of the under projection 36 attempts to return to its original shape, the under projection 36 is sandwiched between the container body 102 and the stepped rib portion 12, and the elastic force of the under projection 36 is maintained.

[0063] This forms a rigid 12-flexible 36-rigid 37 structure. Because the flexible structure is sandwiched between the rigid structures, the under-projections 36 cannot escape upward or toward the radial center, and the under-projections 36 are reliably deformed toward the outer periphery, thereby suppressing liquid leakage caused by gaps due to the steps 105.

[0064] The stepped rib portion 15 functions as a rib (described in detail later). The stepped rib portion 15 resists the pressing force of the stepped protrusion 37 and also assists the rib function of the stepped rib portion 12.

[0065] ~Step Rib~ The stepped rib portion 12 is provided on the lid top surface 10 so as to be adjacent to the lid fitting portion inner wall 33. The stepped rib portion 12 is composed of a width portion 13 and a height portion 14.

[0066] The height portion 14 of the stepped rib portion 12 corresponds to the position of the under-projection 36. In the illustrated example, the upper and lower ends of the under-projection 36 are included between the upper and lower ends of the height portion 14. For example, if the height of the lid fitting inner wall 33 is approximately 10 mm and the major axis diameter of the under-projection 36 is approximately 1 to 3 mm, the height of the height portion 14 is preferably approximately 1 to 4 mm. Alternatively, the height of the height portion 14 is preferably approximately 1.0 to 1.5 times the major axis diameter of the under-projection 36. More specifically, the outer end of the width portion 13 of the stepped rib portion 12 and the lower end of the under-projection 36 are continuous via another minute arc. Note that the inclusion of the minute arc makes the under-projection 36 more easily deformable.

[0067] It is preferable that the width portion 13 is within a predetermined width so that the stepped rib 12 functions as a rib. If the width portion 13 is too long, it will bend and sufficient rib rigidity will not be obtained. If the height of the height portion 14 is about 1 to 4 mm, it is preferable that the width of the width portion 13 is 2 to 6 mm. Alternatively, it is preferable that the width of the width portion 13 is about twice the height of the height portion 14. The above dimensions are examples to make the invention easier to understand, and are not limited to each dimension.

[0068] As a result, the stepped rib portion 12 functions as a rib and resists the elastic force of the under projection 36.

[0069] FIG. 6 is an explanatory diagram of the operation of the stepped rib portion 15.

[0070] The stepped rib portion 15 is provided on the lid top surface 10 so as to be adjacent to the stepped rib portion 12. The stepped rib portion 15 is made up of a width portion 16 and a height portion 17.

[0071] The height portion 17 of the stepped rib portion 15 corresponds to the position of the stepped protrusions 37. In the illustrated example, the lower end position of the height portion 17 of the stepped rib portion 15 roughly corresponds to the lower end positions of the three stepped protrusions 37. The upper end position of the height portion 17 of the stepped rib portion 15 is at a position approximately 1.5 times the total height length of the three stepped protrusions 37. For example, if the height of the lid fitting portion inner wall 33 is approximately 10 mm and the total height of the three stepped protrusions 37 is approximately 3 to 6 mm, the height of the height portion 17 is preferably approximately 2 to 8 mm. Alternatively, the height of the height portion 17 is preferably approximately 0.5 to 1.5 times the total height of the three stepped protrusions 37.

[0072] It is preferable that the width portion 16 is within a predetermined width so that the stepped rib 15 functions as a rib. If the width portion 16 is too long, it will bend and sufficient rib rigidity will not be obtained. If the height of the height portion 17 is about 2 to 8 mm, the width of the width portion 16 is preferably 2 to 6 mm. Alternatively, it is preferable that the width of the width portion 16 is about 0.5 to 1.5 times the height of the height portion 17. The above dimensions are examples to make the invention easier to understand, and are not limited to each dimension.

[0073] As a result, the stepped rib portion 15 resists the pressing force of the stepped projection 37 and also assists the rib function of the stepped rib portion 12 .

[0074] ~Fall verification~ Figure 7 is an explanatory diagram of the behavior when the container is tipped over. The lidded container of the present invention has excellent sealing properties. Therefore, if the container is put back into place within a few seconds after being tipped over, total liquid leakage can be prevented.

[0075] Furthermore, we verified whether the under-projection 36 can suppress liquid leakage caused by the gap due to the container step 105. As shown in the figure, the risk of liquid leakage is highest when the container is tipped over with the container step 105 on the bottom.

[0076] (Verification Example 1) Room temperature coffee was placed inside the container, and the time it took for the liquid to start dripping after tipping over was measured. Comparing five conventional examples without under-projections 36 with five working examples with under-projections 36, the conventional examples started dripping in an average of 4 seconds, while the working examples started dripping in an average of 13 seconds. Although it is not possible to completely prevent liquid leakage due to gaps created by the container step 105, the time it took for the liquid to start dripping was extended by nearly three times, and liquid leakage was suppressed.

[0077] According to the above verification, if the container is returned to its original position within a few seconds after being overturned, liquid leakage due to the gap caused by the step 105 of the container can be prevented.

[0078] (Verification Example 2) Pork soup was placed inside the container and heated in a microwave oven. The time it took for the liquid to start dripping after tipping over was measured. Three conventional examples without under-projections 36 were compared with three working examples with under-projections 36. The conventional examples started dripping after an average of two seconds, while the working examples did not drip even after three minutes. Leakage due to gaps in the container steps 105 was completely prevented.

[0079] The same test was conducted with Yukgaejang and ginger soup. With Yukgaejang, as with the pork soup, the example did not drip even after 3 minutes. With the ginger soup, there were cases where the dripping did not occur even after 3 minutes, cases where the dripping started after 42 seconds, and cases where the dripping started after 14 seconds.

[0080] (Discussion) We were able to confirm the effect of suppressing liquid leakage caused by the gaps created by the container step 105 even when not heated at room temperature. This effect becomes more pronounced when heated in a microwave. It can be assumed that heating the contents softens the resin, and excites the under-projections 36 to flexibly deform so as to close the gaps created by the container step 105.

[0081] It can be assumed that even when the contents are hot beverages such as hot coffee, hot pork miso soup, hot soup, etc., not limited to microwave heating, the steam heat will excite the under-protrusion 36 to flexibly deform so as to close the gap created by the container step 105.

[0082] ~Variations~ The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the above-described technical concept.

[0083] Figure 8 shows one modified example. In the above embodiment, the effect achieved by combining the under projection 36 and the stepped projection 37 has been described, but the effect of the present invention can also be achieved by simply modifying the under projection 36. In the modified example shown in the figure, the stepped projection 37 has been omitted.

[0084] 9 shows another modified example. In the above embodiment, the under-projections 36 are provided around the entire periphery, but in order to prevent liquid leakage due to gaps caused by the container step 105, it is sufficient that some of the under-projections are provided at locations corresponding to the container step 105.

[0085] Another application example is shown in Figure 10. In the above embodiment, attention was focused on the container step 105 that occurs during the manufacturing process of circular paper containers, but the present invention can be widely applied to the risk of liquid leakage caused by step gaps.

[0086] 10A shows a rectangular container formed by folding paper. Steps are generated during the container manufacturing process. The deformation of the under projections 36 can prevent liquid leakage caused by gaps in the steps.

[0087] Figure 10B shows a single-sheet paper container with a bottom, sidewalls, and flange formed from a single sheet of paper. It may also be made from materials other than paper (e.g., resin, aluminum, etc.). Because the container shape is formed from a single sheet of paper, small steps are created in the vertical direction of the body and in the radial direction (perpendicular to the periphery) of the flange. The deformation of the under-projection 36 can prevent liquid leakage caused by gaps in the steps. [Explanation of symbols]

[0088] 1 lid 10 Lid top 11 Center of the lid top 12 Step rib section 13 Width part 14 Height 15 Step rib section 16 Width part 17 Height 18 Step rib section 19 Step rib section 30 Lid fitting part 31 Lid fitting outer wall 32 Top of lid fitting part 33 Inner wall of lid fitting 36 Under projection 37 step protrusion

Claims

1. A resin lid to be used for a paper container having a step on the body, The lid is The top of the lid and A lid fitting portion is provided around the periphery of the lid top surface and fits into a container fitting portion provided on the upper part of the body surface of the container. and The lid fitting portion is The cover has an outer wall, a top portion, and an inner wall; the inner wall of the lid fitting portion faces the body surface of the container, An under-projection projecting in a circumferentially outward direction is provided on the inner wall of the lid fitting portion, at least corresponding to the step on the body surface, The thickness of the under projection is thinner than the thickness of the top portion of the lid fitting portion. Resin lid.

2. The step is made of overlapping paper. The resin lid of claim 1.

3. The under-projection has a curved shape in a vertical cross section. The resin lid of claim 1.

4. The taper angle of the inner wall of the lid fitting portion is equal to the taper angle of the container, The inner wall of the lid fitting portion is provided with a stepped protrusion that protrudes outward in the circumferential direction above the under protrusion. The resin lid of claim 1.

5. The thickness of the under projection is thinner than the thickness of the step projection. The resin lid according to claim 4.

6. A lidded container comprising a paper container and a resin lid, The lid is The container has a lid top surface and a lid fitting portion provided around the periphery of the lid top surface, The lid fitting portion is The container comprises a lid fitting outer wall, a lid fitting top portion, and a lid fitting inner wall, The container comprises: The container has a stepped body surface and a container fitting portion formed on an upper portion of the body surface into which the lid fitting portion fits, the inner wall of the lid fitting portion faces the body surface of the container, An under-projection projecting in a circumferentially outward direction is provided on the inner wall of the lid fitting portion, at least corresponding to the step on the body surface, The thickness of the under projection is thinner than the thickness of the top portion of the lid fitting portion. Container with lid.

7. The step is made of overlapping paper. The resin lid according to claim 6.

8. For hot beverages The container with lid of claim 6.

9. For microwave heating The container with lid of claim 6.

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