JPH0577850A - Thin plastic lid and method for its manufacture - Google Patents

Abstract

PURPOSE:To prevent lids from sticking on one another in order to take them out easily one by one by a method wherein depressed or raised parts are formed on the matching flat surface parts between each adjacent lid in such a manner that each of the depressed or raised parts differs in its direction when they are stacked. CONSTITUTION:A plurality of circular recess parts 6 are formed on flat surface parts 2 of a thin plastic lid 1, each of the circular recess parts is provided with its own narrow depression 9 formed diametrically so as to be divided into two equal parts and each lid differs in the direction of the narrow depression 9. Because of such a structure, when the lids 1 are stacked in any number, the narrow depressions 9 prevent the lids 1 from sticking on one another with gaps left therebetween equal in height to the narrow depression 9. Therefore, the lids can be picked up from the stack easily one by one.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin plastic lid which is formed separately from a container and a method for manufacturing the lid.

[0002]

2. Description of the Related Art Conventionally, a container with a lid has a container body and a lid which are separately formed, a container body having a lid integrally formed in a bendable manner, and a container body. ,
Various proposals have been made, such as one in which the lid is pivotally supported. Figure 5
Shows an example of the container 20 in which the container body 22 and the lid 21 are separated and formed separately. In such a container, there are one in which the container body 22 and the lid 21 are formed of the same material, and the other in which they are formed separately. Among them, the lid made of thin plastic, such as the lid of a folding box (used for bento) made of transparent plastic that allows the inside to be seen through, is conventionally manufactured by press molding. Has been done. In order to accommodate a large number of such plastic lids in a small space or to provide convenient transportation, a large number of such plastic lids are usually accommodated in a laminated manner as shown in FIG.

[0003]

However, in particular,
When the thin plastic lids are stacked, they adhere to each other and it is difficult to separate them one by one. Therefore, there is an inconvenience in that the work of separating the sheets one by one from the stacked ones in actual use and covering them on the container body is inconvenient. Although the lid 21 shown in FIG. 5 has no unevenness, it is usually provided with a reinforcing ridge or a decorative unevenness in practice. Even if the lid is provided with concavities and convexities in this manner, since the lids have the same shape, they are matched with each other and overlapped with each other, so that the inconvenience described above still occurs. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object thereof is to provide a lid of thin-walled plastic that can be easily taken by separating the sheets one by one without adhering to each other when they are stacked, and a manufacturing method thereof. It is what

[0004]

In order to achieve the above-mentioned object, the present invention provides a recessed line having different directions at least between the upper and lower lids on the flat portion at the same position corresponding to the upper and lower sides when superposed. Alternatively, a structure provided with ridges and a thin-walled plastic lid provided with concave ridges or ridges having mutually different directions at least in the flat portions at the same position corresponding to the top and bottom when overlapped Using a mold in which a rotating convex piece corresponding to the concave line or the convex line is rotatably supported at a corresponding position where the concave line or the convex line having different directions is formed in the mold produced by press molding. It is configured to be press-molded.

[0005]

Since the flat portions at the same position corresponding to the upper and lower sides when superposed are provided with the ridges or ridges whose directions are different from each other at least between the upper and lower lids, when the ridges are superposed, the ridges are formed. Alternatively, the ridges are overlapped with each other with a gap corresponding to the depth of the ridges or the height of the ridges without adhering to each other. Therefore, it becomes easy to separate the lids and take them one by one.

Further, since the rotating convex piece is rotatably supported at corresponding portions where the concave or convex ridges having different directions are formed in the die manufactured by press molding, the pressing is performed once. Each time, the rotating convex piece floats and its direction changes naturally. Therefore, when the press-molding is performed using the above-mentioned mold, the concave stripes or the convex stripes formed by the rotating convex pieces at the time of press-molding are manufactured in different directions at least between the upper and lower lids. It

[0007]

Embodiments of the present invention will now be described in detail with reference to the drawings. 1 is a plan view of a thin plastic lid showing an embodiment of the present invention, FIG. 2 is a sectional end view taken along line AA of FIG. 1, and FIG.
FIG. 2 is a sectional end view taken along the line BB of FIG. 1. In the figure, the thin-walled plastic lid 1 is integrally molded in a rectangular shape with plastic, and the flat surface portion 2 has ridges 3 for reinforcement and decoration.
4, 5 and a circular convex portion 6 are provided. Also, the lid 1
An endless groove 7 is provided along the peripheral edge slightly inside the peripheral edge of the flat surface 2 of the container 1. Between the concave groove 7 and the base end 8a of the side wall 8 of the lid 1 on the back surface of the lid 1, A fitting portion 11 to the main body 10 is formed.

A circular convex portion 6 provided on the flat surface portion 2 of the thin plastic lid 1 is provided with a concave stripe 9 which divides the circular shape into half from the center. The recessed line 9 is provided in a different direction for each lid.

However, even if a plurality of thin plastic lids 1 are piled up as shown in FIG.
In addition, since the ridges 9 are provided in different directions for each lid, the ridges 9 interfere with each other and the lids do not come into close contact with each other, and the ridges 9 are overlapped with each other with a height h. Will be Therefore, even if the lids 1 are stacked in a laminated manner, they can be easily separated and picked up one by one.

In the thin plastic lid 1 in the illustrated embodiment, a circular convex portion 6 is provided at each corner of the flat surface portion 2, and a concave streak 9 is provided in the circular convex portion 6.
The present invention only needs to have a configuration in which, when superposed, at least flat portions at the same position corresponding to the upper and lower sides are provided with at least concave and convex ridges having mutually different directions between the upper and lower lids. For example, the circular convex portion 6 can be appropriately selected such as a star shape or a triangle, the circular convex portion 6 may be omitted and only the concave ridge 9 may be formed. The length of the article 9 can be freely selected as long or short. This is because at least the upper and lower lids do not come into close contact with each other when they are piled up and overlapped with each other, so that they overlap each other and have a gap, so that the object can be achieved. Therefore, in the embodiment, it is described that the recessed strips 9 are provided in different directions for each lid, but the meaning is that the directions of the recessed strips 9 may be different for each lid, but when they are polymerized. This means that at least the directions of the recesses 9 of the lids located above and below should be different.

FIG. 4 is an enlarged perspective view of a main part of a metal mold when the thin plastic lid 1 shown in the above embodiment is manufactured by press molding. In the figure, the mold 12 is provided with a circular concave portion 13 and a rotary convex piece 14 in the circular concave portion 13 which is rotatable about the center of the circular shape as an axis and has a substantially circular diameter as the entire length. .. Circular recess 1 of this mold 12
3 and the rotary convex piece 14 are press-formed to form the circular convex portion 6 and the concave ridge 9 of the lid 1, so that the circular convex portion 6 and the concave ridge 9 of the mold 13 are formed. It is provided in a shape corresponding to the location.

If the thin-walled plastic lid 1 is press-molded using the mold 13, the rotary convex piece 1
4 moves in the circular concave portion 13 and changes its direction, so that the concave stripes 9 provided on the circular convex portion 6 of the thin plastic lid 1 are manufactured in different directions for each lid. Although there may be recessed lines 9 in the same direction in a large number of sheets, considering that the thin-walled plastic lid 1 is sequentially polymerized from those manufactured by press molding,
It can be said that at least the directions of the recesses 9 of the lids located at the top and bottom are different. Although only the main part of the mold is shown in FIG. 4, it is natural that the mold is a predetermined mold provided with convex stripes and concave stripes corresponding to the lid to be manufactured, and it is conventionally known. Therefore, detailed description thereof will be omitted.

[0013]

As explained above, according to the thin-walled plastic lid of the present invention, even if they are polymerized and laminated, the lids are polymerized with a small gap, so that they can be easily separated one by one. Can be taken out. Therefore, the work of covering the container body is also easy and efficient. Further, according to the manufacturing method of the present invention, a thin-walled plastic in which concave and convex ridges having mutually different directions at least between lids located at the upper and lower sides are provided on planar portions at the same position corresponding to the upper and lower sides when superposed. The lid can be press-molded in large quantities and easily manufactured.

[Brief description of drawings]

FIG. 1 is a plan view of a thin plastic lid showing an embodiment of the present invention.

FIG. 2 is a cross-sectional end view taken along the line AA of FIG.

3 is a cross-sectional end view taken along line BB of FIG.

FIG. 4 is an enlarged perspective view of a main part of a mold used in the manufacturing method of the present invention.

FIG. 5 is a perspective view showing a conventional example.

FIG. 6 is a vertical cross-sectional front view showing a state in which the lids are stacked and laminated.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thin-walled plastic lid 2 Plane part 6 Circular convex part 9 Recessed line 12 Mold 13 Circular concave part of mold 14 Rotating convex piece

Claims (2)

[Claims] 1. A lid of thin-walled plastic, characterized in that, when overlapped, a flat portion at the same position corresponding to the upper and lower sides is provided with at least concave and convex ridges whose directions are different from each other between the upper and lower lids. .. 2. A thin plastic lid is provided by press-molding a flat portion at the same position corresponding to the upper and lower portions when they are overlapped with each other, and at least upper and lower lid portions are provided with concave or convex ridges having mutually different directions. Press-molding using a mold in which a rotating convex piece corresponding to the concave line or the convex line is rotatably supported at a corresponding position where a concave line or a convex line having different directions is formed in the mold to be manufactured. The method for producing a thin plastic lid according to claim 1, wherein