JP5453965B2 - The structure of the bottom of the cup container - Google Patents

Description

  The present invention relates to a structure of a bottom portion of a cup container that contains a beverage or the like.

  The cup container generally has a cylindrical body and a bottom part (bottom part) that closes the lower end of the body part, is filled with beverages and the like inside, and a lid is sealed at the upper end of the body part by heat sealing or the like. They are then packaged and shipped and sold at stores. Such a cup container is manufactured by sheet molding, for example. The shape of the bottom part of the conventional cup container is composed of an annular grounding part and an inner bottom wall part. This bottom wall is often flat (FIG. 7).

Japanese Utility Model Publication No. 02-099713 JP 2004-0511109 A JP 2004-217266 A

  However, the cup container with a flat bottom wall part is easily deformed by thermal expansion as shown in FIG. 9 during the retort sterilization process or warmer sales, etc. There is a problem that self-sustained stability may not be maintained. Therefore, it has been considered to prevent this deformation of the bottom portion (Patent Document 1, Patent Document 2).

The cup container described in Patent Document 1 is configured to increase the pressure resistance of the bottom part by forming the bottom wall part of the bottom part in a dome shape by recessing inward of the body part ( FIG. 8).
However, when the bottom portion configured in this way exceeds a pressure that can be temporarily withstood and the bottom portion is inverted and bulged by buckling, the buckling state of the bottom portion is maintained even if the pressure is released. There is a problem that it is difficult to restore the original shape.
In the cup container described in Patent Document 2, an attempt has been made to further increase the pressure resistance by providing a rib on the inside of the body part indented in the dome shape and further providing a rib. The described rib structure does not solve the above-mentioned restoration problem.

In addition, various attempts have been made to provide ribs with a dome-shaped bottom portion in PET bottles (for example, Patent Document 3). Here, the PET bottle is formed from a preform by a stretch blow molding method, and it is relatively easy to stretch the body portion thinly while leaving the bottom portion requiring strength thick.
However, since the cup container is generally formed from a sheet having a constant thickness, it is difficult to obtain the strength of the bottom part by adjusting the thickness, and the technical circumstances are completely different.

  The present invention has been made in view of the circumstances as described above, and provides a cup container that can sufficiently increase the pressure resistance of the bottom portion and can be easily restored to its original shape even if temporary buckling occurs. It is intended to do.

  Corresponding to this object, the cup container of the present invention is a bottom part that closes the lower end of the cylindrical body part of the cup container, and the bottom part is an annular grounding part continuous to the lower end of the body part, A ribbed bottom wall portion connected to the inner peripheral edge of the grounding portion and positioned inside the container relative to the grounding portion, and the ribbed bottom wall portion is warped toward the inside of the container. And a plurality of ribs that protrude radially outward from the surface of the warping wall portion and radially inward from the surface of the warping wall portion. It is characterized by being connected to other ribs in the vicinity of the center of the wall.

  In the invention described in claim 1, the bottom portion of the cup container is configured by a curved wall portion that warps in a dome shape and a ribbed bottom wall portion having ribs arranged radially, and the ribs are connected to each other at the center of the bottom portion. Therefore, it is possible to configure a bottom portion that has high pressure resistance and can be easily restored from buckling.

  In the invention described in claim 2, since the cup container is a sheet-molded container, a bottom portion having a high pressure resistance can be obtained in a container made of a flexible material.

  In the invention described in claim 3, since the rib is formed so as to be retracted inward of the container from the grounding portion of the bottom portion, the rib does not interfere with the function of the grounding portion, and the bottom portion is stable. And can be independent.

  In the invention described in claim 4, since the warped wall portion of the ribbed bottom wall portion and the rib are warped in a circular arc shape having different radii, both cooperate to exhibit a high restoring ability.

  In the invention described in claim 5, since the arc length of the warped wall portion and the rib is different, the deformation behavior when the load in the center line direction of the cup body portion is different is different. Demonstrate recovery ability.

Longitudinal section of cup container Top view of cup container Bottom view of cup container Front view of cup container Perspective view of cup container Expansive part explanatory drawing of the bottom part of the cup container It is a figure which shows the conventional cup container, (a) is a longitudinal cross-sectional view, (b) is a bottom view. It is a figure which shows the conventional cup container, (a) is a longitudinal cross-sectional view, (b) is a bottom view. Explanatory drawing which shows the deformation | transformation of the bottom of the conventional cup container

  The details of the present invention will be described below with reference to the drawings showing embodiments. 1 to 6, reference numeral 1 denotes a cup container.

  The cup container 1 has a cylindrical body portion 3 having a center line 2, the upper end of the body portion 3 forms an opening 4, and has a sealing flange 5 at the periphery thereof. The lower end of the body portion 3 is closed by the bottom portion 6.

  The cup container 1 can be manufactured by a known manufacturing method such as pressure forming, vacuum forming, or plug forming using a sheet material. The sheet material is not particularly limited as long as it is suitable for the above-described production method, and a functional material such as a thermoplastic resin such as polyolefin, polyester, and polyamide, a barrier resin, and an oxygen-absorbing resin, and a laminate thereof. It can be used suitably. The bottom portion 6 includes an annular grounding portion 7 around the center line 2 and a ribbed bottom wall portion 8 disposed on the inside thereof. The grounding portion 7 is connected to the lower end of the body portion 3 at the outer peripheral edge, and the ribbed bottom wall portion 8 is connected to the inner peripheral edge portion 12 of the grounding portion 7 at the outer peripheral edge portion 11.

  The ribbed bottom wall 8 is located inside the container in the direction of the center line 2 relative to the position of the grounding portion 7. The ribbed bottom wall portion 8 includes a curved wall portion 13 and a plurality of ribs 14a to 14h. The ribbed bottom wall portion 8 may be directly connected to the inner peripheral edge of the grounding portion 7, but may be connected via a short stepped portion. In the illustrated example, the number of the ribs 14 is 8, but the effect of the present invention is exhibited if there are 3 or more.

  The warping wall portion 13 is formed from the vicinity of the outer peripheral edge portion 11 of the ribbed bottom wall portion 8 to the vicinity of the center portion through which the center line 2 passes, and warps and protrudes toward the inside of the container in the direction of the center line 2.

  The warped wall portion 13 is formed in a fan shape with a predetermined central angle from the outer peripheral edge portion 11 to the central portion 15 of the bottom wall portion 8 with ribs, and is arranged around the center line 2 at predetermined angular intervals, with the ribs 14a to 14h interposed therebetween. Connected and configured.

  The ribs 14a to 14h project from the surface of the warped wall portion 13 from the vicinity of the outer peripheral edge 11 of the ribbed bottom wall portion 8 to the vicinity of the central portion 15 and are formed integrally with the warped wall portion 13 and formed radially. Each of the plurality of ribs 14 a to 14 h is connected to the other ribs 14 a to 14 h in the vicinity of the central portion 15.

  As shown in FIG. 6, the ribs 14 a to 14 h are formed to protrude outward from the outer surface of the warped wall portion 13 in the direction of the center line 2, or from the inner surface of the warped wall portion 13 to the inner side of the container. However, the ribs 14a to 14h do not protrude outward from the grounding portion 7 and are located inside the container from the grounding portion 7. That is, the ridge line 16 of the ribs 14 a to 14 h is located inside the container with respect to the position of the grounding portion 7 in the direction of the center line 2.

The warping wall portion 13 is formed so as to coincide with a virtual partial spherical surface having a radius r ₀ (FIG. 6). The arc length of the imaginary partial spherical surface representing the curved wall portion 13 (in the cross section including the center line 2, from one outer periphery to the other outer periphery through the intersection with the center line 2) is r ₀ · 2θ ₀ is there.
Ridgeline 16 of Riburibu 14a~h projecting outwardly of the container from the outer surface of the wall portion 13 warp coincides with the virtual part spherical surface of radius greater _{r 1} than _{r 0 (r 0 <r 1} ), warp wall 13 is formed so as to intersect with a virtual partial spherical surface representing 13 at the outer peripheral edge of the curved wall portion 13. Two lengths of the ridge line 16 (corresponding to r ₁ · 2θ ₁ in FIG. 6) are smaller than the arc length of the imaginary partial spherical surface representing the curved wall portion 13.
Ribs 14a~h may be formed so as to protrude into the container inwardly from the inner surface of the wall portion 13 warp, the ridge line 16B of case, matches the virtual part spherical surface of the small radius r ₂ than r ₀ (R ₀ > r ₂ ). Further, the length of the two ridgelines 16B (corresponding to r ₂ · 2θ ₂ in FIG. 6) is larger than the arc length of the virtual partial spherical surface representing the curved wall portion 13.
In the illustrated example, the ridgeline 16 (16B) of the warped wall portion 13 and the ribs 14a to 14h is entirely coincident with the virtual partial spherical surface, but may be partially coincident. That is, when viewed in a cross-section including the center line 2, a plurality of arcs having different radii or short straight lines may be smoothly connected.
In such a case, it is only necessary that virtual partial spherical surfaces that coincide in the longest section satisfy the above relationship.

As a form other than the above, for example, the ridge line 16 (16B) of the ribs 14a to 14h is formed so as to coincide with a virtual partial spherical surface obtained by shifting the virtual partial spherical surface representing the curved wall portion 13 as it is (or upward). (R ₀ = r ₁ (r ₀ = r ₂ )). In this case, the outer peripheral edge of the ridge line 16 (16B) of the rib 14 is curved with an appropriate curved surface so as to be smoothly connected to the outer peripheral edge of the wall portion 13.

  In the bottom portion of the cup container configured as described above, the warped wall portion 13 and the ribs 14a to 14h constituting the ribbed bottom wall portion 8 are different in shape and configuration, and are resistant to the internal pressure in the direction of the centerline 2. When the action as a beam is different and a force that deforms the ribs 14a to 14h to the outside of the container due to internal pressure is applied, the ribs 14a to 14h are pressed against and supported by the central portion 15. Even if buckling occurs, a force to easily restore the original shape is generated.

  As is apparent from the above description, according to the present invention, it is possible to obtain a cup container that can sufficiently increase the pressure strength of the bottom portion and can be easily restored to the original shape even if buckling occurs temporarily. .

  Furthermore, according to the present invention, since it is possible to cope with the conventional cup container manufacturing process only by exchanging the mold of the bottom portion, it is possible to carry out without requiring a large investment of mold equipment cost.

DESCRIPTION OF SYMBOLS 1 Cup container 2 Centerline 3 trunk | drum 4 opening 5 sealing flange 6 bottom part 7 grounding part 8 ribbed bottom wall part 11 outer peripheral part 12 inner peripheral part 13 curved wall part 14a-h rib 15 center part 16, 16B ridgeline

Claims (5)

  A bottom portion that closes a lower end of a cylindrical barrel portion of the cup container, the bottom portion being connected to an annular grounding portion that is continuous with a lower end of the barrel portion, and an inner peripheral edge of the grounding portion. A ribbed bottom wall portion located on the inside of the container, the ribbed bottom wall portion warping and projecting toward the inside of the container, and a surface of the warped wall portion A plurality of ribs formed radially and projecting outward from the container or inside the container, and the plurality of ribs are connected to each other in the vicinity of the center of the bottom wall with the ribs. The bottom part structure of the cup container characterized by the above-mentioned.   The bottom part structure of a cup container according to claim 1, wherein the cup container is a sheet forming container.   2. The bottom of the cup container according to claim 1, wherein the plurality of ribs protrude outward from the outer surface of the warped wall part and are located inside the container with respect to the grounding part. Part structure.   The warping wall portion has a portion that coincides with a virtual partial spherical surface having a predetermined radius, and the ridge line of the rib protrudes outward from the outer surface of the warping wall portion, and has a radius larger than the predetermined radius. A portion that coincides with the virtual partial spherical surface, or a portion that protrudes inward from the inner surface of the curved wall portion and coincides with the virtual partial spherical surface having a radius smaller than the predetermined radius. The bottom part structure of the cup container of Claim 1 characterized by the above-mentioned. In the cross section including the center line of the container and the ridge line of the rib, the total length of the two ridge lines of the rib is smaller or larger than the arc length of the imaginary partial spherical surface representing the warping wall part. The bottom part structure of the cup container of Claim 1 characterized by the above-mentioned.

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