JP2006231925A - Creased plastic sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve touch at a crease section after folding of a creased plastic sheet. <P>SOLUTION: The creased plastic sheet is made by preparing a crease-forming concave channel, which has a deep concave channel and a shallow concave channel alternately along its longitudinal direction. The deep concave channel is prepared as an open hole, and the shallow concave channel is prepared so that its sectional view across the longitudinal direction of the crease thickens toward surface side in respectively fixed radii of curvature starting from both ends, wherein curves from both ends meet at the center with each circular arc slightly lowered from respective vertices. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a plastic sheet having a structure corresponding to assembly in an automatic box making machine.

  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.

  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.

  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.

In order to solve the above-mentioned problem, the plastic sheet with a folded ruled line of 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. The deep concave groove portion is provided as an opening, and the shallow concave groove portion has a shape that appears in a cross-section in the length direction of the folding ruled line, and has a thickness on the sheet surface side with a certain radius of curvature from both ends thereof. It is characterized in that it is provided so that the arcs on the surface are slightly lower than the apex at the center.
According to this, since the bottom portion of the ruled line is uneven in the length direction due to the deep groove portion and the shallow groove portion, both the flexibility and rigidity of the sheet can be maintained, and good bendability can be obtained. Since the shallow groove portion is provided in such a manner that the cross-sectional mountain shape, specifically, the thickness increases from the both ends to the sheet surface side with a constant radius of curvature, and the arcs of the surface slightly lower than the apex at the center portion, When the sheet is folded, sharp irregularities are less likely to occur in the ruled line, and the texture is improved.

  When the deep groove portion is an opening, distortion and elastic force generated when the groove is bent are dispersed in the length direction of the groove, and the bending becomes easier than when the deep groove portion is thick.

  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.

  Moreover, the packaging case of this invention can be obtained by punching the sheet | seat of each said structure to a predetermined outline, bending this along a ruled line, and assembling.

  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.

BEST MODE FOR CARRYING OUT THE INVENTION

  The plastic sheet 1 has a concave groove serving as a folding ruled line 2 provided alternately with deep concave groove portions (hereinafter referred to as deep groove portions) 3 and shallow concave groove portions (hereinafter referred to as shallow groove portions) 4 along the length direction. 4 has a structure formed such that the cross section in the lengthwise 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.

  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).

  In the drawing, 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.

  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.

  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.

  The chevron cross section of the shallow groove portion 4 can be provided in a shape appropriately combining the elliptical shape, parabolic shape, semicircular shape, oval shape, other curved shape or planar shape, and FIG. 4R> 4 is an example of the combination. Is shown. 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 at 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.

  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. .

  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 a ruled line 2 including a deep groove portion 3 and a shallow groove portion 4 having an elliptical cross section formed from the front surface side of the sheet 1 and an elliptical cross section at the formation position of the shallow groove portion 4 on the back surface side of the sheet 1. The concave groove 5 is provided. 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.

  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.

  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.

(A), (B) is sectional drawing of the ruled line part which shows embodiment of this invention which provided thickness in the deep groove part. (A)-(D) are sectional drawing of the ruled line part which shows embodiment of this invention which provided the opening in the deep groove part and formed the ruled line. (A), (B) is sectional drawing of the ruled line part which shows embodiment of this invention which formed the cross section of the shallow groove part combining two curved surfaces. (A)-(F) is a figure which shows the cross section of the shallow groove part formed combining the some surface. (A)-(C) are sectional drawing of the ruled line part which shows embodiment of this invention which made the thickness of the deep groove part differ continuously. (A), (B) is sectional drawing of the ruled line part which shows embodiment of this invention which provided the groove on both the front and back of the sheet | seat. The embodiment of this invention which inclined the boundary line of a deep groove part and a shallow groove part with respect to the ruled line direction is shown, (A) is a principal part top view of a sheet | seat, (B) is the BB line of (A). FIG. (A), (B) is sectional drawing of the ruled line part of the plastic sheet of a conventional structure.

Explanation of symbols

1 Plastic Sheet 2 Ruled Line 3 Deep Groove 4 Shallow Groove 5 Groove

Claims (2)

A concave groove that is 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,
The deep concave groove portion is provided as an opening, and the shallow concave groove portion has a shape appearing in a cross section in the length direction of the folding ruled line, and the thickness increases from the both end sides to the sheet surface side with a certain radius of curvature, respectively. A plastic sheet with folded ruled lines, characterized in that the arcs on the surface are provided so that they intersect slightly lower than the top.   A packaging case in which the plastic sheet according to claim 1 is punched into a predetermined contour and is folded along a ruled line.

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