JP3964599B2 - Folded ruled plastic sheet and packaging case - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plastic sheet having a structure corresponding to assembly in an automatic box making machine.
[0002]
[Prior art]
As a plastic sheet that is bent into a packaging case, as shown in a cross-sectional view in FIG. 8, along the length direction, at the bottom of the concave groove 12 that forms a ruled line provided on the surface of the sheet 11. There is known a structure in which irregularities are formed (FIG. (A)) or intermittent holes are formed (FIG. (B)), and deep grooves 13 and shallow grooves 14 are alternately provided. Yes.
[0003]
[Problems to be solved by the invention]
Although the conventional structure has better bendability than the structure with no irregularities at the bottom of the ruled line, depending on the conditions such as the material and thickness of the sheet when assembling the sheet using a box making machine The case cannot be assembled due to insufficient bending, and the case may be deformed even if it can be assembled. On the other hand, if it bends more than necessary, the case could be deformed.
In addition, as the sheet is bent, the uneven portions exposed from the concave grooves are raised up, and the touch may be deteriorated or cracks and tears may be formed.
[0004]
[Problems to be solved by the invention]
In view of such problems with the prior art, the present invention assembles robustly and cleanly without causing poor processing such as insufficient bending or excessive bending when a plastic sheet with bent ruled lines is automatically assembled. The challenge is to be able to.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the plastic sheet with a folded ruled line according to the present invention is a plastic sheet with a folded ruled line formed by alternately forming deep concave grooves and shallow concave grooves along the length direction of the concave grooves to be the folded ruled lines. In addition, the shallow groove portion is provided so that the cross section in the length direction is a mountain shape, and a concave groove as viewed from the back surface side of the sheet is formed at each position where the shallow groove portion is formed on the back surface side of the sheet. It is characterized by providing .
According to this, since the bottom part of the ruled line is uneven in the length direction by the deep groove part and the shallow groove part, both the flexibility and rigidity of the sheet can be maintained, and good bendability can be obtained. Since the shallow groove portion has a mountain-shaped cross section, sharp irregularities are hardly generated in the ruled line when the sheet is bent, and the texture is improved.
[0006]
The shape of the chevron appearing in the cross section of the shallow groove part includes an asymmetrical shape in which the central part is high and both sides are lowered at an equal rate, and the top part is biased to one side and both sides are gradually lowered. It is. Further, a plurality of small chevron shapes may be connected to an integral chevron shape so that there are a plurality of top portions, or the surfaces may be provided step by step so that the heights are different in steps. In short, it is only necessary to have at least one top portion and to be continuously different in height from both sides of the top portion to the deep groove portion.
[0007]
In any shape, it is preferable that the top portion has a curved surface shape or a flat shape . If the top portion is provided in a curved shape or a flat shape, the resin in this portion is compressed and the strength is increased. Therefore, when the sheet is folded, it does not stand up, and no crack or tear occurs.
[0008]
The shape of the chevron depends on the material and thickness of the sheet, the width and length of the groove, and the dimensional ratio of the deep groove to the shallow groove so that no processing defects occur when the sheet is bent along the ruled line. It can be selected as appropriate. For example chevron portion or elliptical, shaped as a part of a parabola shape including a parabolic point, semicircular, Ru can be, eg oval. In order to improve the bendability of the sheet, when the mountain shape is provided in a semicircular shape or an oval shape, it is preferable to set the center of the surface arc to be located inside the sheet.
[0009]
Incidentally, the deep groove portion arranged alternately shallow groove portion includes a case having an appropriate thickness from the sheet back surface, there Ru if the opening by penetrating the rear surface side. When the deep groove is an open hole, the strain and elastic force generated when it is bent are dispersed in the length direction of the groove and it is easier to bend than when the deep groove has a thickness. As described above, the hole or the thickness may be selected according to the material and thickness of the sheet, the molding condition of the concave groove, etc. so as not to cause processing defects.
[0010]
Further, the concave grooves serving as ruled lines can be provided on both sides of the sheet in addition to being provided on one side of the sheet. When providing on both surfaces of a sheet | seat, the recessed groove of the surface of one side should just be comprised as mentioned above.
[0011]
Furthermore, the packaging case of the present invention, stamping the sheet of each component to a predetermined contour, bent along this to borders, it is possible to obtain by assembling.
[0012]
In addition, as a plastic sheet to which the present invention is applied, a single or composite sheet such as polyvinyl chloride, polyethylene, polypropylene, polyester, or polycarbonate can be used. The thickness of the sheet is usually about 0.1 to 1.0 mm, but is not limited thereto.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In the plastic sheet of the present invention, the concave groove serving as the folding ruled line is provided with a deep concave groove portion (hereinafter referred to as a deep groove portion) and a shallow concave groove portion (hereinafter referred to as a shallow groove portion) alternately along the length direction. It has a structure formed such that the cross section in the length direction is a mountain shape.
Hereinafter, an example of an embodiment of a ruled line formed on a sheet will be described with reference to the drawing showing a cross section of a ruled line part. In the figure, reference numeral 1 denotes a sheet, 2 denotes a ruled line, 3 denotes a deep groove portion, and 4 denotes a shallow groove portion.
[0014]
FIG. 1 shows a form in which a ruled line 2 is formed by providing a thickness in the deep groove portion 3.
In FIG. 6A, the shallow groove portion 4 is provided in a curved surface shape in which the cross section in the ruled line direction forms a part of an elliptical shape (CD).
In FIG. 5B, the shallow groove portion 4 is provided in a curved surface shape in which the cross section in the ruled line direction forms a part of a parabolic shape (H) including a parabolic point (OH).
[0015]
In the figure, the lengths (L3, L4) in the ruled line direction of the deep groove portion 3 and the shallow groove portion 4 are substantially the same length, and the thickness (D3) of the deep groove portion 3 is substantially 1 / th of the sheet thickness (D1). However, the present invention is not limited to this, and can be appropriately set according to the material and thickness of the sheet. The thickness (D4) of the shallow groove part 4 is also the same.
[0016]
FIG. 2 shows a form in which the ruled line 2 is formed by providing the deep groove portion 3 in an opening penetrating the back surface side of the sheet 1 on the back surface side. In this embodiment, the deep groove portion 3 has a thickness (D3) of 0 mm.
In FIG. 2A, the shallow groove portion 4 is provided in a curved surface shape in which the cross section in the ruled line direction forms a part of an elliptical shape.
FIG. 4B shows the shallow groove portion 4 having a curved surface shape in which the cross section in the ruled line direction forms a part of a parabolic shape including a parabolic point.
FIG. 6C shows the shallow groove portion 4 having a curved surface shape in which the cross section in the ruled line direction forms a semicircular shape. In this embodiment, the center (O) of the surface arc of the shallow groove portion 4 is set so as to be positioned at the back side edge of the sheet 1.
FIG. 4D shows the shallow groove portion 4 provided with a curved surface shape in which the cross section in the ruled line direction forms an oval shape. In this embodiment, the center (O) of the surface arc of the shallow groove portion 4 is set so as to be located closer to the inner side of the sheet than the edge on the back surface side of the sheet 1.
[0017]
FIG. 3 shows a form in which the shallow groove portion 4 is formed in a curved surface shape in which a mountain shape appearing in a cross section in the ruled line direction is a combination of two arcs having a center point inside the sheet.
FIG. 4A shows the ruled line 2 formed with the deep groove 3 having a thickness, and FIG. 4B shows the deep groove 3 formed with the opening. Is increased from the deep groove 3 to the sheet surface side with a constant radius of curvature, and the arcs of the surface at the center part are provided so as to be slightly lower than the apex.
[0018]
The chevron cross section of the shallow groove portion 4 can be provided in a shape appropriately combining the elliptical shape, the parabolic shape, the semicircular shape, the elliptical shape, and other curved surface shapes and planar shapes, and FIG. 4 shows an example of the combination. ing.
3A, in the same way as FIG. 3, the cross section of the shallow groove portion 4 is provided in a curved surface shape combining two arcs having a center point inside the seat. Is designed to be almost the same as the height on both sides.
FIG. 5B shows the shallow groove section 4 having a cross section formed by arranging two trapezoidal shapes.
FIG. 4C shows a cross section of the shallow groove portion 4 in which two trapezoidal shapes are arranged, the side surfaces are curved, and the upper surface is substantially flat.
FIG. 4D shows a cross section of the shallow groove portion 4 having a curved surface shape in which three curved surfaces are arranged at substantially the same height.
FIG. 5 (E) shows a cross section of the shallow groove portion 4 having a curved surface shape composed of three curved surfaces, with the curved surfaces on both sides being the same height and the curved surface at the center being higher than that. It is provided in the shape of a cocoon.
FIG. 8F shows a curved surface shape in which the central curved surface shown in FIG. 8E is further divided by a curved surface having a smaller arc, and four arcs are combined as a whole.
[0019]
FIG. 5 shows the deep groove portions 3 in each of the above figures provided with a constant thickness in the ruled line direction, whereas the thicknesses are gradually different along the ruled line direction.
FIG. 6A shows that when the cross section of the ruled line 2 is viewed, the portion where the deepest groove portion 3 has the smallest thickness and the top portion where the shallowest groove portion 4 has the largest thickness are connected by a straight line, and the entire ruled line has a triangular waveform. The cross-section is provided.
FIG. 5B shows the top portion of the shallow groove portion 4 shown in FIG.
(C) in FIG. 2 is provided so that the deepest groove portion 3 shown in FIG. 4A has the smallest thickness portion and the top portion of the shallow groove portion 4 so that the entire ruled line has a curved waveform cross section. .
[0020]
FIG. 6 shows a form in which concave grooves to be ruled lines are provided on both surfaces of the sheet 1. In FIG. 2A, a ruled line 2 including a deep groove portion 3 and a shallow groove portion 4 having an elliptical cross section is formed from the front surface side of the sheet 1, and a predetermined depth along the ruled line 2 is formed on the back surface side of the sheet 1. A concave groove 5 is provided. The concave groove 5 is provided at a depth smaller than the thickness of the deep groove portion 3 in order to prevent damage when the sheet 1 is bent. FIG. 2B shows the formation of the ruled line 2 composed of the deep groove portion 3 and the shallow groove portion 4 formed of a part of an elliptical cross section from the front surface side of the sheet 1, and the formation position of the shallow groove portion 4 on the back surface side of the sheet 1. Is provided with a concave groove 5 made of a part of an elliptical cross section. In this case, the concave groove 5 may be provided with a cross-sectional shape similar to that of the shallow groove portion 4 or may have a different cross-sectional shape.
[0021]
In each of the drawings, the orientation of the deep groove portions 3 and the shallow groove portions 4 that are alternately provided inside the ruled line may be such that the boundary line between the two parts is perpendicular or inclined with respect to the ruled line direction. .
For example, FIG. 7A is a plan view of the sheet 1 including the ruled line 2, and FIG. 7B shows a cross section along the ruled line 2. As shown in the figure, the deep groove portion 3 and the shallow groove portion 4 of the ruled line 2 are shown. The boundary line can also be provided inclined with respect to the ruled line direction.
[0022]
The configuration of the ruled line 2 shown in each drawing is an example, and the plastic sheet of the present invention is not limited to the illustrated form. The ruled line 2 is appropriately formed by combining the deep groove part 3 and the shallow groove part 4 in each drawing, or combining these with a known ruled line structure.
[Brief description of the drawings]
FIGS. 1A and 1B are cross-sectional views of a ruled line portion showing an embodiment of the present invention in which a deep groove is provided with a thickness.
FIGS. 2A to 2D are cross-sectional views of a ruled line portion showing an embodiment of the present invention in which a ruled line is formed by providing an opening in a deep groove portion.
3A and 3B are cross-sectional views of a ruled line portion showing an embodiment of the present invention in which a cross section of a shallow groove portion is formed by combining two curved surfaces.
4A to 4F are views showing a cross section of a shallow groove portion formed by combining a plurality of surfaces. FIG.
5A to 5C are cross-sectional views of a ruled line portion showing an embodiment of the present invention in which the thickness of the deep groove portion is continuously changed.
6A and 6B are cross-sectional views of a ruled line portion showing an embodiment of the present invention in which concave grooves are provided on both front and back surfaces of a sheet.
7 shows an embodiment of the present invention in which the boundary line between the deep groove portion and the shallow groove portion is inclined with respect to the ruled line direction. FIG. 7 (A) is a plan view of the main part of the sheet, and FIG. It is sectional drawing along the BB line.
8A and 8B are cross-sectional views of a ruled line portion of a plastic sheet having a conventional structure.
[Explanation of symbols]
1 Plastic Sheet 2 Ruled Line 3 Deep Groove 4 Shallow Groove 5 Groove

Claims (3)

A concave groove to be a folding ruled line is a plastic sheet with a folding ruled line formed by alternately providing deep concave grooves and shallow concave grooves along the length direction thereof,
A structure in which the shallow groove portion is provided so that a cross section in the length direction is a mountain shape, and a concave groove as viewed from the back surface side of the sheet is provided at each position where the shallow groove portion is formed on the back surface side of the sheet. equipped with a folding ruled plastic sheet. The plastic sheet with a folded ruled line according to claim 1, wherein the shallow groove portion is formed to be a part of an elliptical cross section or a part of a parabolic shape including a parabola. A packaging case in which the plastic sheet according to claim 1 or 2 is punched into a predetermined contour and is folded along a ruled line.

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