JP4783403B2 - Container lid and packaging container - Google Patents

Description

  The present invention is obtained by molding a thermoplastic resin sheet, and includes a top surface portion and a side wall portion hanging from the periphery thereof, and a container lid used for packaging over the opening portion of the container, and the container lid being opened. The present invention relates to a packaging container comprising a container main body that can be detachably attached to a part. The container lid may be integrated with the container body or may be a separate body.

Conventionally, as a packaging container for packaging fresh fish, meat, fruits, vegetables, cooked foods, etc., the container body made by thermoforming a thermoplastic resin sheet into a desired shape and detachable at its opening A packaging container comprising a container lid attached to the container is widely used.
In many cases, this type of packaging container displays food products in a container body, the container lid is tightened, and the packaged products are stacked in multiple stages. For this reason, not only a certain level of mechanical strength is required for the container body of the packaging container, but also the container lid has a mechanical strength (particularly compression resistance) that does not crush when stacked in multiple stages as described above. It is requested that you do.

As a method for increasing the rigidity of a packaging container in which a thermoplastic resin sheet is molded, a technique for forming a thread end at the bottom of the packaging container is disclosed (for example, see Patent Documents 1 and 2).
Usually, a thread end is often provided at a position slightly inside from the boundary between the bottom and the side wall. In this case, even if the yarn bottom is formed, if the pressure is applied from above, the yarn bottom is pushed down inward, so that the effect of improving the rigidity of the bottom of the container is hardly exhibited.
JP-A-57-43807 JP 2006-334972 A

  The present invention relates to a packaging container in which the container lid is not easily deformed or crushed when the container body is covered with the container body, or when the container containing the food is stacked, the legs and ridges are depressed or stepped. It is an object of the present invention to provide a packaging container that is unlikely to slip and cause the upper and lower containers to be displaced and the container lid to be deformed by weight and not to tilt or collapse.

In order to achieve the above-mentioned object, the present invention is a container lid that is detachably attached to a container main body, is obtained by molding a thermoplastic resin sheet, and includes a top surface portion and a side wall portion that hangs down from the periphery thereof. The top surface portion has a polygonal shape in plan view, and each corner portion of the top surface portion accommodates feet provided on the bottom of the container body when another container body different from the above is stacked thereon. A thread recess is provided, and a thread bottom protrusion is provided around the boundary between the top surface, the side wall, and the foot recess , and the thread bottom protrusion is an end of the top surface. In the vertical direction from the inner wall portion and the outer wall portion folded back to the top and hanging down to a height substantially equal to the top surface portion and connected to the side wall portion and the footrest recess, in the flat portion of the top surface portion Height h from the top of the top surface to the top of the thread butt-shaped convex with respect to the thickness t 3 to 15 times t, and the total [a + b] of the inner wall thickness a and the outer wall thickness b at a height ½ h that is approximately the middle of the height h is 0.4 to 2.0 times t, and A container lid is provided in which a gap d at 1 / 2h between an inner wall portion and an outer wall portion is 13 times or less of t .

  In the container lid of the present invention, it is preferable that the outer wall portion and the side wall portion of the yarn tail-like convex portion are continuous vertically or steeply without a horizontal step.

  The present invention also provides a packaging container comprising the above-described container lid according to the present invention and a container body that can be detachably attached to the opening.

  ADVANTAGE OF THE INVENTION According to this invention, the container lid which can improve the compression resistance of a container lid, and a container lid and a packaging container which a container lid is not easily crushed when a product is piled up, or the product stacked in multiple steps cannot tilt or collapse can be provided. .

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 are views showing an embodiment of the container of the present invention, FIG. 1 is a perspective view of the container lid 1 of the present embodiment, and FIG. 2 is a packaging in which the container lid 1 and the container body 11 are combined. FIG. 3 is an enlarged cross-sectional view of a portion A in FIG. In these drawings, reference numeral 1 is a container lid, 2 is a top surface part, 3 is a side wall part, 4 is a thread-butt-like convex part, 4a is an inner wall part, 4b is an outer wall part, 5 is a rib, 6 is a recessed part for a footrest, 7 is a fitting part, 8 is a flange part, 11 is a container main body, 12 is a flange part, 13 is a leg.

  The container lid 1 of the present embodiment is obtained by molding a thermoplastic resin sheet, and includes a top surface portion 2 and a side wall portion 3 hanging from the periphery thereof, and has a thread end shape at the boundary between the top surface portion 2 and the side wall portion 3. Convex portions 4 are provided, and ribs 5 are provided on the side wall portions 3 so that one end of the ribs 5 extends downward in contact with or close to the yarn tail-like convex portions 4.

  The thermoplastic resin sheet constituting the container lid 1 is a thermoplastic resin sheet used in a conventionally known packaging container, for example, a polystyrene resin sheet, a polyethylene resin sheet, a polypropylene resin sheet, or a polyethylene terephthalate system. A thermoplastic resin sheet such as a resin sheet may be used, and is not particularly limited. Usually, a transparent thin thermoplastic resin sheet is used. The container lid 1 is produced by thermoforming (such as vacuum forming, pressure forming, vacuum pressure forming, hot plate forming) the thermoplastic resin sheet. When the container lid 1 is manufactured, the yarn tail-shaped convex portion 4 can be formed using, for example, the manufacturing apparatus and the manufacturing method disclosed in Patent Document 1 and Patent Document 2.

  In this embodiment, as shown in FIG. 3, the yarn tail-like convex portion 4 formed on the container lid 1 is folded back at the top portion with the inner wall portion 4 a raised vertically from the end portion of the top surface portion 2. It consists of an outer wall portion 4 b that hangs down to a height substantially equal to that of the top surface portion 2 and is connected to the side wall portion 3.

  A height h from the upper surface of the top surface portion 2 to the top of the thread tail-like convex portion 4 can be in the range of 3 to 15 times t with reference to the thickness t at the flat portion of the top surface portion 2. When the height h is less than 3 times the thickness t, the rigidity is insufficient, and the stacking feet 13 and the ridges provided on the bottom of the container can easily get over the thread-bottom projection 4. Even if it exceeds 15 times, the reinforcing effect against bending is not improved so much and it is useless, and a wasteful space is required in the packaging case when the container lids 1 are stacked and transported.

  The dimension of the gap d between the inner wall portion 4a and the outer wall portion 4b of the yarn tail-like convex portion 4 depends on the thickness of the sheet, but the flat portion of the top surface portion 2 considered to be closest to the thickness of the sheet before molding. The range can be 13 times or less of the thickness t. A narrow gap d is preferable because it is less likely to bend when pressure is applied from above in the vicinity of the boundary between the top surface portion 2 and the side wall portion 3 of the container lid 1. The gap d can be set to a size exceeding 13 times t, but the effect of improving the rigidity is reduced, and in this case, the ribs can be sufficiently formed by normal molding rather than the yarn tail formation.

  The sum [a + b] of the thickness a of the inner wall portion 4a and the thickness b of the outer wall portion 4b at a height ½h that is substantially the middle of the height h of the yarn tail-like convex portion 4 is the thickness t of the flat portion of the top surface portion 2. It is preferable to set it in the range of 0.4 to 2.0 times. When the total thickness [a + b] is less than 0.4 times t, the rigidity of the thread tail-like convex part 4 is not exhibited, and when it exceeds 2.0 times, the height of the thread tail-like convex part 4 is set to a predetermined value. Can not be the height of.

  In this container lid 1, the outer wall 4 b and the side wall 3 of the yarn tail-like convex portion 4 are directly continuous vertically or steeply without passing through an intervening structure such as a large bend or a horizontal step. preferable. As a result, even if pressure is applied to the yarn tail-like convex portion 4 from above, it is difficult to tilt, so that it can withstand stronger pressure.

  In the present embodiment, the yarn tail-like convex portion 4 formed on the container lid 1 is provided over the entire circumference at the boundary portion between the top surface portion 2 and the side wall portion 3. Thereby, the perimeter of the top surface part 2 and the side wall part 3 is reinforced by the yarn bottom-like convex part 4, and the compression resistance of the container lid 1 can be improved over the entire top surface part 2.

In the present embodiment, the rib 5 provided on the side wall 3 of the container lid 1 is formed of a concave portion in which a part of the side wall is recessed inward, and a plurality of (examples shown in FIG. 6 are provided at almost equal intervals. Further, in this example, the rib 5 is provided in a shape that is narrowed from the top to the bottom. By providing these ribs 5 on the side wall 3 in a state where one end is in contact with or close to the yarn tail-like convex portion 4, the container lid is combined with the compression resistance improving effect by the yarn tail-like convex portion 4. The compression resistance of 1 can be further improved.
In addition, the structure of this rib 5 is not limited to this illustration, It is good also as the convex part which bulged a part of side wall part 3 outside, and the rib which combined the recessed part and the convex part may be sufficient as it. . Further, the shape of the rib 5 is not limited to this example, and may be a rib having the same width in the vertical direction or a rib having a shape spreading from top to bottom.

  In the container lid 1 of the present embodiment, a fitting portion 7 that is fitted to the flange 12 of the container main body 11 that covers the container lid 1 is provided below the side wall portion 3. In this example, the fitting portion 7 of the container lid 1 is fitted to the outside of the flange 12 of the container main body 11, so-called an external fitting method, but the fitting structure between the container lid 1 and the container main body 11 is as follows. Without being limited to this example, an inner fitting method in which the fitting portion on the lid side is elastically press-fitted into the opening on the container body side, or a fitting method having both outer fitting and inner fitting. It may be adopted.

  The container lid 1 of the present embodiment has a quadrilateral shape in plan view, and is provided at the bottom of the container body 1 when another container body 11 is stacked on each corner of the top surface 2. A footrest recess 6 in which the foot 13 is accommodated is provided. By adopting a structure in which the foot 13 of another container body 11 is accommodated in the recess 6 for placing the foot, the contents are put in the container body 11, the container lid 1 is covered, and the packaged products are stacked in multiple stages. In addition, each product can be made stable and difficult to collapse.

  FIG. 2 is a side view showing an embodiment of the packaging container of the present invention. The packaging container according to this embodiment includes the above-described container lid 1 according to the present invention and a container main body 11 to which the container lid 1 can be detachably attached to the opening. In the present embodiment, the container main body 11 includes a bottom portion having a substantially quadrilateral shape and a side wall portion that is erected upward from the periphery of the container, and is a tray type obtained by molding a thermoplastic resin sheet. Although the container is illustrated, the shape of the container main body 11 is not limited to this example, and various kinds of containers conventionally known as packaging containers can be appropriately selected and used.

  The material of the container body 11 is a thermoplastic resin sheet used for a conventionally known packaging container, for example, a thermoplastic resin sheet such as a polystyrene resin sheet, a polyethylene resin sheet, a polypropylene resin sheet, or a polyethylene terephthalate resin sheet. There is no particular limitation as long as it is. The container body 11 is manufactured by thermoforming (vacuum forming, pressure forming, vacuum / pressure forming, hot plate forming, etc.) the thermoplastic resin sheet. The thermoplastic resin sheet may be a non-foamed sheet, a foam sheet having a low expansion ratio, or a laminated sheet obtained by laminating a plurality of types of resin sheets and resin films. Furthermore, a film on which a design of a desired color tone, a mark, a symbol, a letter, a number, or the like has been printed can be laminated on the thermoplastic resin sheet.

  Since the packaging container of this embodiment can improve the compression resistance of the container lid 1 as described above, the container lid 1 is not crushed when the products are stacked, and the products stacked in multiple stages are not easily tilted or collapsed. Become.

The above-described embodiment is merely an example, and the present invention is not limited to the description of this embodiment (and an example described later), and various modifications and changes are possible.
For example, not only the container lid 1 but also the bottom end-shaped convex part 4 may be formed on the bottom side of the container main body 11.
In FIG. 2, the container lid 1 and the container main body 11 are illustrated as separate packaging containers. However, even if the container main body and the container lid are integrally and continuously folded, It is also possible to form the thread tail-like convex portion 4 on both the container lid and the container main body bottom.
In this way, when the yarn bottom-like convex portion is formed on both the container lid and the container main body bottom, when one of the yarn bottom-like convex portion of the container lid and the yarn bottom-like convex portion of the container main body is fitted into the other, Tilts and load collapse are less likely to occur when stacking containers that contain food or the like and are closed.

FIG. 3 shows the boundary between the top surface portion and the side wall portion according to the manufacturing method disclosed in Patent Document 2, using a die having a fixed die and a moving die for forming a yarn tail, by vacuum / pressure forming. A container lid provided with a thread-like convex portion (hereinafter referred to as a thread tail) having a shape was manufactured.
As the molding sheet, a transparent A-PET resin sheet having a thickness of 0.18 mm, 0.21 mm, and 0.23 mm was used.
The container lid is composed of a top surface portion, a side wall portion, a heel portion extended by folding the side wall portion outward and a skirt portion extending the heel portion downward, and the size thereof is as follows.
-The size of the top surface is 163mm long x 107mm wide.
-The side wall portion has an internal dimension of 174 mm long by 117 mm wide at the boundary portion connected to the heel portion at its lower end portion, and a height (from the ridge upper surface to the top surface lower surface) is 23 mm.
-The outer diameter of the skirt is 188 mm long × 132 mm wide × 33 mm high to the top surface.
Moreover, the rib of the vertical direction was provided in the side wall part. The rib is an inverted trapezoidal shape having a top side of 22 mm, a bottom side of 11 mm, and a height of 22 mm, and is composed of a concave part whose surface from the top side to the bottom side is steeper than the peripheral part and whose bottom side is recessed by 3 mm in the lid inner direction. The longitudinal ribs were formed at two equal intervals on the side wall portion on the long side and at one location on the central portion of the short side.

A plurality of container lids were manufactured by using three types of molding sheets and changing the height of the yarn tail and the gap between the inner wall portion and the outer wall portion. Table 1 shows the dimensions of the prototype container lid.
For compressive strength, prepare a wooden mold with a size that fits the inside of the skirt when the entire circumference of the buttock comes into contact with the container lid, and covers the container lid of the subject over the wooden mold. A wooden board was placed on the top surface (on the thread tail), and the maximum load was read when compressed 2 mm at a speed of 400 mm / min. Tensilon (manufactured by Shimadzu Corporation, Autograph AG-1) was used as a measuring device.
The measurement method of the dimension of each part of the shape | molded container lid measured the magnification of 50 times about the cross section of the container lid using the optical microscope (the Keyence company make, VH-8000). The results are shown in Table 1.

From the results shown in Table 1, the container lid in which the yarn bottom in the range shown in claim 3 was formed showed a significant improvement in rigidity.
In Comparative Examples 1 to 3, no yarn end was formed.
In the example (Comparative Example 4) in which the yarn bottom was lowered, the compression strength was not sufficiently improved as compared with the case where there was no yarn bottom, and the difficulty of displacement when stacked was not improved.
In the example (Comparative Example 5) in which the yarn bottom was increased, the height of the yarn bottom was not stable, and the inner wall portion and the outer wall portion of the yarn bottom became too thin, and the effect of improving the compressive strength was not sufficient.
In the example (Comparative Example 6) in which the gap between the yarn ends was wide, the sheet was not stably folded and the shape was disordered.

It is a perspective view of the container lid of one embodiment of the present invention. It is a side view of the packaging container of one Embodiment of this invention. It is an expanded sectional view of the A section of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Container lid, 2 ... Top surface part, 3 ... Side wall part, 4 ... Yarn bottom-like convex part, 4a ... Inner wall part, 4b ... Outer wall part, 5 ... Rib, 6 ... Recessed part for footrest, 7 ... Fitting part, 8 ... flange part, 11 ... container main body, 12 ... flange part, 13 ... foot.

Claims (3)

In a container lid that is detachably attached to the container body, obtained by molding a thermoplastic resin sheet, and comprising a top surface part and a side wall part hanging from the periphery thereof,
The top surface portion has a polygonal shape in plan view, and a footrest provided on the bottom of the container body is accommodated in each corner of the top surface portion when a container body different from the above is stacked thereon. A recess is provided,
A thread tail-like convex part is provided so as to go around the boundary part at the boundary part of the top surface part and the side wall part and the recessed part for the footrest ,
The thread-bottom convex part consists of an inner wall part that rises vertically from the edge of the top surface part, and an outer wall that is folded back at the top part and hangs down to a height approximately equal to the top surface part, and is connected to the side wall part and the footrest concave part. The height h from the top surface top surface to the top of the thread tail-like convex portion is 3 to 15 times t, which is substantially in the middle of the height h, with reference to the thickness t in the flat portion of the top surface portion. The total [a + b] of the inner wall thickness a and the outer wall thickness b at height 1 / 2h is 0.4 to 2.0 times t, and the gap d at 1 / 2h between the inner wall portion and the outer wall portion is t. The container lid characterized by being 13 times or less . 2. The container lid according to claim 1 , wherein the outer wall portion and the side wall portion of the yarn tail-like convex portion are continuous with a vertical or steep inclination without a horizontal step. A packaging container comprising the container lid according to claim 1 and a container main body to which the container lid can be detachably attached to an opening.

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