JP4200296B2 - Plastic packaging container - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic packaging container in which a plurality of divided trays for storing frozen foods and the like are separably connected by perforations.
[0002]
[Prior art]
Conventionally, this type of plastic container is generally connected by a perforation provided with a plurality of subdivided trays on the flange portion. And in order to make it difficult to bend at the perforation when it is lifted, there are those in which the perforation is corrugated (see, for example, Patent Document 1) or those in which a rib is formed in the flange portion (for example, Patent Document 2). To 6). Of these, the rib-formed one has the effect of improving the strength in addition to the effect of making it difficult to bend at the perforation. When this type of plastic packaging container is manufactured, after the plastic material is molded, a perforation for separation is formed by a cutting blade for perforation (see, for example, Patent Document 6).
[0003]
[Patent Document 1]
JP-A-11-301632 [0004]
[Patent Document 2]
Japanese Patent No. 3101576 gazette
[Patent Document 3]
JP 2000-296829 A [0006]
[Patent Document 4]
Japanese Patent Laid-Open No. 11-321838
[Patent Document 5]
Japanese Patent Laid-Open No. 11-227735
[Patent Document 6]
Utility Model Registration No. 3055599 [0009]
[Problems to be solved by the invention]
However, the ribs formed as in the above prior art are excellent in shape retention and bending resistance, but have the following problems.
[0010]
When this type of plastic packaging container is manufactured, the plastic material is molded and then the perforation cutting blade is formed by the perforation cutting blade. When the perforation is formed, the perforation cutting blade is the corner of the rib. When hitting, there is a case where the ribs are deformed or out of shape at the corners of the ribs, or the perforations are not uniform.
[0011]
The perforation is for a perforation that has slits at regular intervals from above, with the receiving recess up and the flange down, on a support that is made of plastic and has slits through which the blades pass. It is formed by lowering the cutting blade.
[0012]
However, as shown in FIG. 7, when the cutting edge of the perforated cutting blade N hits the corner of the rib 10, the external force by the cutting edge concentrates on the corner vertex and exceeds the allowable stress of the material. It is considered that irregularities in the perforations (unevenness that deviates from a straight line) associated with these deformations and deformations occur. In FIG. 7, a perforated cut blade having an oblique cutting edge has been described as an example, but the same applies to the case where the cutting edges are aligned in the horizontal direction.
[0013]
Accordingly, an object of the present invention is to provide a plastic packaging container having a shape that is unlikely to be deformed, deformed, or uneven in the perforated surface even when hit with a perforated cutting blade during perforation formation.
[0014]
[Means for Solving the Problems]
The above-described object of the present invention is to provide a separation sewing machine comprising a plurality of subdividing trays each having an accommodating recess and a flange portion connected by the flange portions, and an intermittent slit in the flange portion connecting the subdivision trays. A plastic packaging container in which eyes are formed, and substantially spherical convex portions are formed at required intervals at positions where the perforations of the flange portion pass, and the perforations are formed on tops of the substantially spherical convex portions. This is achieved by a plastic packaging container in which a joint is formed and a connecting portion from the substantially spherical convex portion to the flat surface of the flange portion is formed by a smooth curved surface.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention is described below with reference to FIGS. In addition, the same code | symbol was attached | subjected to the same component through all drawings including the prior art.
[0016]
In the plastic packaging container 1, a plurality of subdivision trays 4 each having an accommodation recess 2 and a flange portion 3 are connected to each other by the flange portions 3. A separation perforation M formed by intermittent slits is formed in the flange portion 3.
[0017]
At positions where the perforation M of the flange portion 3 passes, substantially spherical convex portions 5 are formed at required intervals. As shown in an enlarged view in FIG. 3, the joint J of the perforation M is formed on the top of the substantially spherical convex portion 5. As shown in an enlarged view in the reverse direction in FIG. 4, the connecting portion 6 from the substantially spherical convex portion 5 to the flat surface of the flange portion 3 is formed by a smooth curved surface. It is important that there are no corners between the flat part of the part 3.
[0018]
In the plastic packaging container 1 having the above-described configuration, when the perforation M is formed, the conventional problems such as deformation, shape loss, and perforation irregularities are eliminated, which is considered to be due to the reason described later. .
[0019]
When forming the perforation, as shown in FIG. 4, when the perforation cutting blade N is lowered from above, the perforation cut is formed at the connecting portion 6 extending from the substantially spherical convex portion 5 to the flat portion of the flange portion 3. When the cutting edge of the blade N hits, the connecting portion 6 is formed with a curved surface and the substantially spherical convex portion 5 is also formed with a substantially spherical surface, so that the connecting portion 6 bends as shown by an imaginary line in FIG. At the same time, it is considered that the contact with the cutting edge of the perforated cutting blade N is close to line contact. For this reason, it is considered that the internal stress applied from the cutting edge of the perforated cutting blade N to the connecting portion 6 is reduced as compared with the conventional case where contact is made in a point contact manner at the corner of the rib. Further, it is considered that the cutting edge of the perforated cutting blade N and the connecting portion 6 are point contact-like contact at the beginning of contact, but are shifted to line contact-like contact due to bending, and the perforation is performed at the time of the transition. It is considered that slip occurs between the cutting edge of the cutting blade N and the connecting portion 6 and acts easily by the slip.
[0020]
The substantially spherical convex portion 5 has a maximum outer diameter L (see FIG. 5) smaller than the full width W of the flange portion 3 connected by the perforation M, that is, the flange portion 3 connected by the perforation M. It is formed in a size that can be accommodated within the width W. For example, as shown in a plan view in FIG. 6, if the maximum outer diameter L of the substantially spherical convex portion 5 ′ is larger than the width W of the flange portion 3, the flange portion 3, the substantially spherical convex portion 5, and the housing concave portion 2 This is because an acute angle K is formed at the portion where the side wall intersects, which causes deformation and the like due to stress concentration during perforation.
[0021]
Further, the curvature radius R (see FIG. 4) of the substantially spherical convex portion 5 is 1.2 to 2.0 times the half value of the maximum outer diameter L (that is, corresponding to L / 2). It is preferable to set it as the magnitude | size. When the curvature radius R is smaller than 1.2 times the half value (= L / 2) of the maximum outer diameter L, the maximum height H (FIG. 4) of the substantially spherical convex portion 5 is increased. As a result, the angle α formed between the substantially spherical convex portion 5 and the surface of the flange portion 3 is reduced, and the effect of line contact with the perforated cut blade N is reduced. On the other hand, when the radius of curvature R is larger than 2.0 times the half value (= L / 2) of the maximum outer diameter L, the maximum height H of the substantially spherical convex portion 5 becomes small. This is because the bending resistance described in the prior art is reduced.
[0022]
That is, the joint J of the perforation M is formed at the top of the substantially spherical convex portion 5 in order to provide bending resistance that makes it difficult to bend at the perforation surface M when it is lifted up.
[0023]
However, in the plastic packaging container according to the present invention, the perforated joint J is formed only at the top of the substantially spherical convex portion 5, and the joint is not formed at other portions. Accordingly, it is difficult to bend with respect to the bending moment in the X direction in FIG. 5B, and when the plastic packaging container 1 is lifted with the substantially spherical convex portion 5 facing upward, it is difficult to bend at the perforation. It has become.
[0024]
However, as shown in FIG. 2, it is easy to bend when a bending moment in the opposite direction is applied from the outside. Therefore, when the plastic packaging container 1 is lifted with the substantially spherical convex portion 5 on the lower side. It is easy to bend at the perforation M.
[0025]
This is because, when frozen food or the like is stored in the plastic container 1 and lined up in the store as a product, the substantially spherical convex portions 5 are arranged on the upper side so that the contents can be seen. Since it is normal to pick up one flange portion 3 of the subdivision tray 4 with a finger while the substantially spherical convex portion 5 is on the upper side, it is bent at the perforation M in that state. It is necessary to make it difficult.
[0026]
On the other hand, in the reverse state, if the perforation M is not cut, the perforation M may be bent, and the number of joints can be reduced. Even in the reverse state, the body itself is lightweight if it is in a state in which frozen food or the like is not stored in the storage recess, so that it does not bend at the perforation just by lifting.
[0027]
【The invention's effect】
As is clear from the above description, according to the plastic packaging container of the present invention, even when the perforation cutting blade hits at the time of perforation formation, deformation, deformation of the shape, or unevenness of the perforation surface hardly occurs.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a plastic packaging container according to the present invention.
FIG. 2 is a perspective view showing a state where the plastic packaging container of FIG. 1 is bent.
3 is an enlarged perspective view showing a part of the plastic packaging container of FIG. 1. FIG.
4 is an enlarged longitudinal sectional view showing a substantially spherical convex portion, which is a component of the plastic packaging container of FIG. 1, together with a perforated cutting blade. FIG.
5 shows the plastic packaging container of FIG. 1, in which FIG. 5 (a) is a plan view and FIG. 5 (b) is a front view.
FIG. 6 is a plan view showing a substantially spherical convex portion of an aspect different from the present invention.
FIG. 7 is a cross-sectional view showing an enlarged rib of a conventional plastic packaging container together with a perforated cutting blade.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Plastic packaging container 2 Containment recessed part 3 Flange part 4 Subdivision tray 5 Spherical surface convex part 6 Connection part S Slit M Perforation

Claims (1)

A plurality of subdivision trays having an accommodating recess and a flange portion are connected by the flange portions, and a separation perforation formed by intermittent slits is formed in the flange portion connecting the subdivision trays. A packaging container,
A substantially spherical convex portion is formed at a required interval at a position where the perforation of the flange portion passes, and a perforation seam is formed at the top of the substantially spherical convex portion, from the substantially spherical convex portion. A plastic packaging container, wherein a connecting portion reaching a flat surface of the flange portion is formed by a smooth curved surface.

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