JP5990076B2 - Plastic sheet with bent ruled line, ruled line blade for plastic sheet and packaging container - Google Patents

Description

  The present invention relates to a plastic sheet with a folded ruled line assembled in a packaging container for display and sale by folding the sheet along a folded ruled line provided on the surface, and a ruled line blade for attaching the ruled line to the sheet.

2. Description of the Related Art As containers for storing articles such as cosmetics and daily necessities for display and sales, packaging containers that are assembled into a box shape by folding a transparent plastic sheet are used.
A plastic sheet assembled in a box-shaped container is formed by providing a folding ruled line on the surface, and this bent ruled line is deep in the thickness direction of the plastic sheet with a substantially V-shaped cross section substantially corresponding to the edge of a sharp ruled line blade. When formed, when the plastic sheet is bent along the folding ruled line, the cracks and holes are likely to occur in the acute angle part of the bottom part where the thickness of the ruled line is thin, while on the other hand, when the plastic sheet is formed shallowly, The folding property of the plastic sheet is lowered, making it difficult to assemble the container, and the bent portion along the folding ruled line is likely to be warped and wavy, so that the assembled container is not good in appearance.

  Therefore, in order to satisfy both the bending strength that does not cause a crack and the bending property that does not hinder the assembly operation, as shown in FIG. 20, a fine rope-like ridge is formed on the bottom surface portion 102 of the folding ruled line 101 as shown in FIG. The present inventors have developed a plastic sheet 100 provided with a so-called “rope pattern ruled line” provided with a shape in which 103 is arranged on the entire bottom surface 102 (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2003-292203

The folding ruled line 101 shown in FIG. 20 provides sufficient bending strength even when formed on a sheet having a low elongation rate, such as biodegradable plastic, and can be folded into a plastic sheet with a light force. As a result, the spring back property of the plastic sheet folded along the folding ruled line may deteriorate.
In that case, if the plastic sheet is stored along the folding ruled line before being assembled into the packaging container, it becomes difficult to perform the work that causes the plastic sheet folded in a flat shape three-dimensionally, When an external force is applied to the packaging container assembled in a box shape and deformed, it is difficult to restore the original shape. Further, the durability of the bent portion of the plastic sheet 100 provided with the bent ruled line 101 is low, and cracks are likely to occur along the bent ruled line 101 when the assembly and deployment of the plastic sheet 100 are repeated.

  In view of such problems of the prior art, the present invention provides a folded creased plastic sheet having both good foldability and folding strength without deteriorating the springback property of the plastic sheet folded along the creased ruled line. It is a problem to obtain.

In order to solve the above problems, the present invention provides a plastic sheet with a folded ruled line having a concave folded ruled line on the surface thereof, wherein the concave folded ruled line is curved and inclined opposite to each other, and both side parts. The bottom surface portion is formed of a convex portion extending from the bottom surface and extending in a direction inclined by a predetermined angle with respect to the attaching direction of the bent ruled line. And having a configuration in which a cross section between adjacent convex portions is provided in a cross-sectional shape that is curved continuously with the both side surface portions.
Further, the present invention is used when a concave bent ruled line is attached to a bent part of a plastic sheet, and in the ruled line blade for a plastic sheet having a tip portion provided in a curved cross-sectional shape, the tip of the ruled line blade A configuration in which concave blade portions extending in a direction inclined at a predetermined angle with respect to the direction in which the bent ruled line is attached are arranged on the top surface portion, and curved surfaces are provided on both sides of the concave blade portion at the tip of the ruled line blade. It is characterized by having.
The packaging container of this invention is a thing of the structure assembled using the bending ruled line plastic sheet of the said structure, bend | folding along the said bending ruled line.

  The plastic sheet is formed of, for example, a biodegradable plastic such as polypropylene (PP), polyester (PET), or polylactic acid (PLA), or a single or composite plastic of other resin materials. It is composed of a transparent or translucent sheet formed to a predetermined thickness included in the range of about 1 mm. That is, when a folding ruled line is attached to a plastic sheet, a single sheet or plural sheets of ruled blades are applied to each bent part of the plastic sheet with a pressure according to the material, thickness, strength, hardness, etc. of the plastic sheet. Press to form.

As an embodiment, the bent ruled line is formed by arranging a plurality of convex portions protruding from the bottom surface portion at appropriate intervals, or by arranging the convex portions continuously over the entire bottom surface portion. The dimension of each part of the folding ruled line including the convex part can be set to a dimension included in a predetermined range suitable for folding the plastic sheet.
Further, the ruled line blade is formed by arranging a plurality of concave blade parts at an appropriate interval at the tip part of the curved ruled line blade, or the concave blade part is continuously provided over the entire tip part of the ruled line blade. The dimensions of each part of the ruled line blade including the concave blade part are included in a predetermined range suitable for forming a bent ruled line attached to the plastic sheet. Can be set to dimensions.

In the plastic sheet with a bent ruled line and the ruled line blade for plastic sheet having the above-mentioned configuration, the bent ruled line of the plastic sheet and the blade part of the ruled line blade can be formed with a size and an angle included in the following predetermined range.
That is, as shown in FIGS. 4 to 8 for the bent ruled line and FIGS. 10 to 15 for the ruled line blade, the depth (a1) of the convex part of the bent ruled line and the edge of the ruled line blade are shown. For example, the height (a2) is set to a dimension (for example, about 0.1 mm) included in a range of about 0.01 mm to about 0.3 mm, and the width (b1) of the convex portion and the width (b2) of the blade portion are set to, for example, It is set to a dimension (for example, approximately 0.5 mm) included in a range of approximately 0.05 mm to approximately 0.8 mm, and the trough pitch (c1) of the convex portion and the cutting edge pitch (c2) of the blade portion are, for example, approximately 0.1 mm. To a dimension (approximately 0.3 mm, for example) included in the range of approximately 1.0 mm, and the curvature radius (d1) of the bottom surface of the bent ruled line and the curvature radius (d2) of the tip of the ruled line blade are set to, for example, Radius within the range of 1 to 1.5 mm (for example, plastic Set to approximately 0.4 mm depending on the thickness of the tick sheet), and the angle (e1) of the convex portion and the angle (e2) of the concave blade portion that are inclined or intersected at a predetermined angle with respect to the ruled line attachment direction (f), For example, an angle included in a range of approximately 10 degrees to approximately 90 degrees (for example, approximately 30 degrees) is set, and a thickness (g) of the ruled line blade is a predetermined thickness included in a range of approximately 0.5 mm to approximately 2.0 mm. Set to.
Further, the width (h) of the folded ruled line is set to a dimension (for example, approximately 0.6 mm) included in the range of about 0.05 mm to about 0.8 mm, and the convex portion is about 80% or more of the width dimension of the folded ruled line. It is preferable to set so as to occupy the width of.

  If the dimensions are within the above range (for example, depth, height, width, angle, radius of curvature, etc.), change the dimensions of the bent ruled line projections and ruled line blades to the desired combination can do. In addition, each shape is combined with any specific cross-sectional shape such as a substantially semicircular shape, a substantially arc shape, a substantially trapezoidal shape, a substantially square shape, a substantially triangular shape, etc. having a smooth curved surface when viewed from the side, for example. It can be provided in a shape.

  If the depth (a1) and width (b1) of the convex part of the bent ruled line and the depth (a2) and width (b2) of the ruled line blade are larger than the set range, they are attached to the plastic sheet. Since the feel and bending characteristics of the bent ruled line are deteriorated, and if it is set to be smaller than the setting range, the strength of the blade edge is lowered, and a sufficient effect for attaching the bent ruled line cannot be obtained. It is preferable to provide the dimensions within the range.

Also, if the radius of curvature (d2) and angle (e2) of the blade of the ruled line blade are set larger than the above setting range, a large pressing force is required when attaching a bent ruled line, making it difficult to process, and plastic The sheet is warped, corrugated, etc., making it difficult to bend mechanically, and the plastic sheet has poor folding characteristics. On the other hand, if each is smaller than the set range, the strength of the cutting edge is lowered and the life is shortened. Therefore, it is preferable to provide each at a value included in the set range.
Further, if the radius of curvature (d1) of the bottom surface of the bent ruled line and the angle (e1) of the convex part with respect to the ruled line attaching direction are set larger than the set range, the folding characteristic of the plastic sheet is deteriorated. While the plastic sheet is easily bent along the folded ruled line, cracks are likely to be generated in the ruled line.
Furthermore, the angle (e1) of the convex portion and the angle (e2) of the blade portion of the ruled line blade with respect to the ruled line attaching direction of the bent ruled line are set to an inclination angle of about 15 degrees within the range of about 10 degrees to about 90 degrees. Preferably it is set. If the angle is set to 15 degrees, the plastic sheet can be easily bent along the folding ruled line, and even if the folding is repeated, the ruled line breaks or the sheet breaks along the ruled line. The bending characteristics and durability can be improved.

  Moreover, if the width (b1) of the convex part and the width (b2) of the blade part are set larger than the set range, the bending characteristic of the plastic sheet is deteriorated. On the other hand, if the width is set smaller than the set range, Since the strength is lowered and a sufficient effect for attaching the bent ruled line cannot be obtained, it is preferable to provide the dimensions within the set range.

  Further, if the ratio of the width (b1) of the convex portion to the width (h) of the folding ruled line is less than 80%, the plastic sheet is further improved in bending properties, but the spring back property is lowered and flattened. Therefore, it is difficult to perform the three-dimensional operation of the plastic sheet folded into a shape, and the durability when the assembly and deployment of the plastic sheet are repeated is also reduced. Therefore, the width of the convex portion (b1 ) Is preferably provided in the dimension of the ratio of the set range.

  According to the present invention, the folded ruled line attached to the plastic sheet has a plurality of shallow convex parts arranged in a substantially rope pattern on the bottom part of the ruled line, and each convex part is inclined with respect to the ruled line attaching direction. Even if the hand touches along the folded portion of the plastic sheet, there is almost no roughness, and the packaging container assembled by folding the plastic sheet is comfortable to touch, Even if fibers such as clothes come into contact with the surface of the packaging container, they do not get caught, and the fibers are not frayed or part of the packaging container is not damaged by the contact.

  When the bent ruled line having the above structure is attached to a plastic sheet, the part to which the convex part in the ruled line is attached is formed by being pushed and spread obliquely with respect to the ruled line attaching direction. Even when a bending force is applied to a thin part (deep part) without increasing the density, it becomes difficult to tear, and even a plastic sheet with a low elongation rate, such as biodegradable plastic, can be easily and easily folded. Can be processed. Also, for example, even if cracks, holes, etc. occur in the folding ruled line, or the bent ruled line is formed so deeply that the bent ruled line is generated, when the plastic sheet is bent along the folded ruled line, the convex portion is deformed into a flat state. Therefore, foreign matter such as dust and moisture is difficult to invade from the bent ruled line in which the crack or the like has occurred, and the articles stored in the packaging container are prevented from being contaminated by the intrusion of foreign matter, and the quality and commercial value are improved. Can keep.

  In addition, the bent ruled line is formed on both sides of the bottom part when the convex part arranged on the bottom part is thick and the part on both sides of the convex part is thin, and the plastic sheet is bent along the bent ruled line. Since the two thin portions are bent at the center, the plastic sheet has good folding characteristics and can be bent smoothly. In addition, the bent ruled line is formed by arranging convex parts on the bottom surface thereof, so that the volume and thickness of the part provided with the convex parts are more than double those of the folded ruled line formed on the conventional plastic sheet, and Since the cross section between the convex parts is provided in a curved cross-sectional shape, even when it is formed on a plastic sheet with a low elongation rate such as biodegradable plastic, it has an appropriate spring back property while improving the folding characteristics. Even if the assembly to the packaging container and the development to the sheet are repeated, the plastic sheet and the packaging container obtained by assembling the plastic sheet are more durable.

It is an expanded view which shows the plastic sheet with a bending ruled line of one Embodiment of this invention. It is a perspective view which shows the assembly state of the plastic sheet of FIG. It is a principal part fracture perspective view of the sheet | seat which expands and shows the folding ruled line formed in the plastic sheet | seat of FIG. FIG. 4 is an enlarged plan view of a sheet showing a groove shape of a bent ruled line shown in FIG. 3. FIG. 5 is a cross-sectional view taken along line A1-A1 of FIG. FIG. 5 is an enlarged sectional view taken along line B1-B1 of FIG. It is an expanded sectional view along the C1-C1 line of FIG. FIG. 5 is an enlarged cross-sectional view taken along line D1-D1 of FIG. It is a principal part fracture perspective view of the ruled line blade for plastic sheets which attaches the bending ruled line of FIG. It is a side view which shows the blade shape of the ruled line blade of FIG. FIG. 10 is a plan view of the blade edge side showing the blade shape of the ruled line blade of FIG. 9. It is sectional drawing along the A2-A2 line | wire of FIG. FIG. 12 is an enlarged sectional view taken along line B2-B2 of FIG. It is an expanded sectional view along the C2-C2 line of FIG. FIG. 12 is an enlarged cross-sectional view taken along line D2-D2 of FIG. It is a figure for demonstrating the method of producing the ruled line blade of FIG. It is a principal part fracture | rupture perspective view of the sheet | seat which is the plastic sheet of other embodiment of this invention, and expands and shows the bending ruled line which arranged the several convex part group at predetermined intervals. FIG. 18 is an enlarged plan view of a sheet showing a groove shape of a bent ruled line shown in FIG. 17. It is a principal part fracture perspective view of the ruled line blade for plastic sheets which attaches the bending ruled line of FIG. It is a principal part fracture perspective view of a sheet which expands and shows a folding ruled line formed in the conventional plastic sheet.

Preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a folded ruled plastic sheet used for assembling a packaging container in which articles are stored. The plastic sheet 1 is transparent or translucent having a thickness of about 0.1 mm to about 1 mm, for example. 2 on both sides of the front portion 1a having a substantially rectangular shape when viewed from the front when the sheet is punched or punched into a shape in which the packaging container in the assembled state shown in FIG. Left and right side surface portions 1b, a rear surface portion 1c continuous to the right edge portion of one side surface portion 1b, a joint portion 1d continuously connected to the right edge portion of the rear surface portion 1c, and upper and lower edges of the side surface portion 1b. A fold portion 1e... Continuous with the upper surface portion, an upper surface portion 1f continuous with the upper edge portion of the front surface portion 1a and a lower surface portion 1g continuous with the lower edge portion, and an upper surface portion 1f and lower surface portion 1g Folded part with the folded part 1h , It is formed by attaching a concave bent border 2 by ruled line blade 4 to be described later.
Moreover, you may provide the hole (illustration omitted) for suspending the plastic sheet 1 assembled in the container form in the support part (illustration omitted) connected with the upper edge part of the rear surface part 1c.

As shown in FIGS. 3 to 8, the folding ruled line 2 attached to the bent portion of the plastic sheet 1 includes a pair of side portions 2a facing each other while being curved with a predetermined curvature, and the side portions 2a. 2a is formed in a substantially curved cross-sectional shape at one end side and a continuous bottom surface portion 2b, and the convex portion 3 is raised from the surface of the bottom surface portion 2b by a predetermined ratio than the maximum depth of the folding ruled line 2, and A plurality of the convex portions 3 are continuously arranged in the length direction along the bottom surface portion 2b of the bent ruled line 2, and substantially the same as the ruled line attaching direction f of the bent ruled line 2 as shown in FIG. It is inclined at a predetermined angle e1 in a direction (a direction different from the bending direction) and arranged so as to have a substantially rope pattern when viewed from the plane side.
The bent ruled line 2 is formed so that the thickness of the bottom surface portion 2b becomes a predetermined thickness included in a range of about 0.08 mm to about 0.3 mm, for example.

  The convex portion 3 is formed so that the depth of the folding ruled line 2 on the convex portion 3 gradually increases from the central portion to both end portions, and exhibits a smooth curved surface when the convex portion 3 is viewed from the side. It is formed in a semicircular shape, the depth a1 of the convex portion 3 is set to about 0.1 mm (see FIG. 5), the width b1 is set to about 0.5 mm (see FIG. 4), and the valley pitch c1 is set to approximately 0.3 mm, and the inclination angle e1 with respect to the ruled line attachment direction f is set to approximately 30 degrees. Further, the curvature radius d1 of the bottom surface 2b of the bent ruled line 2 is set to about 0.4 mm (see FIG. 7).

  In addition, when the assembly operation of the plastic sheet 1 having the above-described configuration is mechanically performed, the curvature of the folding ruled line 2 formed at the bent portion of the front surface portion 1a, the side surface portion 1b, the rear surface portion 1c, and the joint portion 1d. The radius d1 is set to a value (approximately 0.3 mm) in which bending is allowed in a predetermined direction, and the curvature of the folded ruled line 2 formed at the bent portion between the folded portion 1e, the upper surface portion 1f, and the lower surface portion 1g. The radius d1 is preferably set to a value (approximately 0.4 mm) that allows bending to the inside and outside.

  On the other hand, as shown in FIGS. 9 to 15, the plastic sheet ruled blade 4 used when attaching the bent ruled line 2 is a pair of side portions facing each other while being curved with a predetermined curvature. 4a and a top surface portion 4b that is continuous with one end side of the side surface portions 4a and 4a are formed into a curved cross-sectional shape, and a blade portion 5 that exhibits a concave cross-sectional shape when viewed from the side surface is formed along the top surface portion 4b of the ruled line blade 4. As shown in FIG. 11, a plurality of rows are provided in the longitudinal direction, and as shown in FIG. 11, a predetermined angle e <b> 2 toward substantially the same direction (a direction different from the sheet folding direction) with respect to the ruled line attaching direction f of the ruled line blade 4. The concave blade portions 5 are arranged so as to have a substantially rope pattern when viewed from the blade edge side.

The blade portion 5 is formed in a groove shape that gradually becomes shallower from the center portion to both end portions, and is formed in a substantially semicircular border so as to exhibit a smooth curved surface when viewed from the side surface. The height a2 of the part 5 is set to about 0.1 mm (see FIG. 12), the width b2 is set to about 0.5 mm (see FIG. 11), the cutting edge pitch c2 is set to about 0.3 mm, and the inclination angle e2 is formed at an angle inclined at approximately 30 degrees with respect to the ruled line attachment direction f.
Further, the radius of curvature d2 of the blade portion 5 is set to about 0.4 mm (see FIG. 14), and the thickness g of the ruled line blade 4 is set to a predetermined thickness included in a range of about 0.5 mm to about 2.0 mm. By doing so, the bent ruled line 2 attached to the plastic sheet 1 using the ruled line blade 4 is formed such that the width (b1) of the convex portion with respect to the width (h) is 80% or more. ing.

  For example, as shown in FIG. 16, the ruled line blade 4 continuously cuts the curved tip of the ruled line blade 4 at a predetermined inclination angle and depth using a cutting means 6 such as a cylindrical file or a wire. Can be produced. Depending on the material, thickness, strength, hardness, etc. of the plastic sheet 1, each dimension (for example, depth, height, width, etc.) of the convex part 3 constituting the folded ruled line 2 and the blade part 5 constituting the ruled line blade 4 is described. The angle, the radius of curvature, etc.) may be changed as appropriate.

  Next, a method of attaching the bent ruled line 2 to the plastic sheet 1 using the ruled line blade 4 having the above configuration and an assembling method of the plastic sheet 1 provided with the bent ruled line 2 will be described.

  First, when the bent ruled line 2 is attached, the single or plural ruled line blades 4 shown in FIGS. 9 to 14 are punched into a shape of a predetermined form shown in FIG. Bending of the front part 1a, the side part 1b, the rear part 1c, the joined part 1d, the folded part 1e, the upper part 1f, and the lower part 1g of the plastic sheet 1 that has been punched or punched The bent ruled lines 2 shown in FIGS. 3 to 8 are formed by pressing the bent portions with the portions with pressure according to the material, thickness, strength, hardness, and the like of the plastic sheet 1. Alternatively, it may be formed by pressing while heating to a predetermined temperature.

  On the other hand, when assembling the plastic sheet 1 with the folding ruled line 2 into a substantially rectangular container shape when viewed from the side surface shown in FIG. 2, the front surface portion 1a, the side surface portion 1b, the rear surface portion 1c, and the joint portion 1d , The folded portion 1e, the upper surface portion 1f and the lower surface portion 1g are bent in a predetermined direction and angle along the folding ruled line 2, and the joint portion 1d continuously provided on one side surface portion and the other side surface portion 1b. Are bonded and fixed with an adhesive, and the plastic sheet 1 can be assembled to the packaging container by a processing procedure in which the folded portion 1e on the lower edge side, the upper surface portion 1f and the lower surface portion 1g are folded inward and closed.

  When the packaging container is assembled and the article is stored, the folding part 1e on the upper edge side, the upper face part 1f and the lower face part 1g are once folded outward to open and closed after the article is stored. Assembly by a machine (not shown) and storage of articles by an automatic storage machine (not shown) can be easily performed by simple operations and operations. Note that the bonding portion 1d may be bonded and fixed by, for example, welding or high-frequency welding.

  According to this embodiment, the bent ruled line 2 attached to the plastic sheet 1 has a plurality of shallow convex parts 3 arranged in a substantially rope pattern on the bottom surface part 2b of the ruled line, and each convex part 3 is provided with a ruled line. Since it is provided in a shape that is inclined with respect to the direction, there is almost no roughness even if a hand touches along the bent portion of the plastic sheet 1, and the packaging container that is assembled by folding the plastic sheet 1 is touchable. It will be comfortable and will not get caught even if clothes or other fibers come into contact with the surface of the packaging container, and the fibers will not fray or damage the packaging container due to the contact. .

  When the bent ruled line 2 is attached to the plastic sheet 1, the part of the ruled line to which the convex part 3 is attached is formed so as to be spread obliquely with respect to the ruled line attaching direction. Even if it is a plastic sheet 1 having a low elongation rate, such as a biodegradable plastic, the folding ruled line 2 can be easily formed even when the bending force is applied to the thin part (deep part) without increasing the density. And it becomes possible to process easily. Further, for example, even if a crack or a hole is generated in the folding ruled line 2 or the bent ruled line 2 is formed so deeply as to occur, the convex portion 3 is formed when the plastic sheet 1 is folded along the folded ruled line 2. Is deformed into a flat state and adheres, so that foreign matters such as dust and moisture are less likely to enter from the bent ruled line 2 where the crack or the like has occurred, and the articles stored in the packaging container are prevented from being contaminated by the intrusion of foreign matter, The quality and commercial value can be maintained.

  Further, the bent ruled line 2 has a thick portion of the convex portion 3 arranged on the bottom surface portion 2b and a thin portion on both sides of the convex portion 3, and when the plastic sheet 1 is bent along the bent ruled line 2, Since it bends centering on the two thin parts formed in the both sides of the bottom face part 2b, the bending characteristic of the plastic sheet 1 becomes favorable and can be bent smoothly. Furthermore, the folding ruled line 2 has the volume and thickness of the portion provided with the convex part 3 doubled as compared with the folding ruled line formed on the conventional plastic sheet by arranging the convex part 3 on the bottom surface part 2b. In addition, since the cross section between the convex portions 3 is provided in a curved cross-sectional shape, even when formed on a plastic sheet 1 having a small elongation such as a biodegradable plastic, the bending characteristics are improved. However, moderate springback is ensured, and even if the assembly to the packaging container and the development to the sheet are repeated, the plastic sheet 1 and the packaging container obtained by assembling the plastic sheet 1 are not easily damaged along the folding ruled line 2. Improves.

  As another method of processing the bent ruled line 2, for example, the ruled line blade 4 heated to a predetermined temperature is pressed against the bent part of the plastic sheet 1 or processed, or a substantially disc-shaped or substantially loop-shaped rotating ruled line blade (illustrated). (Omitted) can be rotated and processed while being pressed against the plastic sheet 1.

FIGS. 17 and 18 show another embodiment of the plastic sheet 1 of the present invention, in which the bent ruled lines 2 are arranged on the bottom surface portion 2b, and a plurality of rows of convex portions 3 are arranged at predetermined intervals. Is formed.
As shown in FIG. 19, the bending formation 2 uses a ruled line blade 4 in which a plurality of sets of blade portions 5... Are arranged at predetermined intervals corresponding to the arrangement of the convex portions 3. It is attached to the plastic sheet 1 and can exhibit the same operations and effects as the plastic sheet 1 of the above-described form.

〔Example〕
In order to confirm how much the protrusions 3 arranged in a rope pattern in the bent ruled line 2 are practically preferable, a ruled line blade 4 having a different inclination angle e2 of the blade part 5 is used. 1 was formed, and a folding ruled plastic sheet 1 shown in FIG. 1 was formed. Each sheet was subjected to an evaluation test of bendability and durability, and the appearance (appearance) when assembled in the case of FIG. 2 was evaluated.

Example 1
A plastic sheet 1 with a bent ruled line was formed using a plastic sheet made of polylactic acid resin having a thickness of 1 mm.
The ruled line blade 4 having the shape shown in FIGS. 9 to 15 was used. That is, the ruled line blade 4 is formed in a groove shape in which the blade portion 5 gradually becomes shallower from the center portion to both end portions, and is formed in a substantially semicircular border so as to exhibit a smooth curved surface when viewed from the side surface. The height a2 is set to about 0.1 mm, the width b2 is set to about 0.5 mm, the cutting edge pitch c2 is set to about 0.3 mm, and the inclination angle e2 is inclined at about 15 degrees with respect to the ruled line attachment direction f. What was formed and set was used.
The bent ruled line 2 of the formed plastic sheet 1 with the bent ruled line has an inclination angle e1 of the convex part 3 with respect to the ruled line attaching direction f of approximately 15 degrees.

(Example 2)
Using the same material and the same thickness plastic sheet as in Example 1, and using the ruled line blade 4 under the same conditions as in Example 1 except that the inclination angle e2 of the blade part 5 of the ruled line blade 4 is approximately 40 degrees A plastic sheet 1 was formed.
The bent ruled line 2 of the formed plastic sheet 1 with the bent ruled line has an inclination angle e1 of the convex part 3 with respect to the ruled line attaching direction f of approximately 40 degrees.

(Example 3)
Using a plastic sheet of the same material and thickness as in Example 1, and using the ruled line blade 4 under the same conditions as in Example 1 except that the inclination angle e2 of the blade part 5 of the ruled line blade 4 is approximately 10 degrees, A plastic sheet 1 was formed.
The bent ruled line 2 of the formed plastic sheet 1 with the bent ruled line has an inclination angle e1 of the convex part 3 with respect to the ruled line attaching direction f of approximately 10 degrees.

(Evaluation results)
About the plastic sheet 1 formed in each Example, the touch at the time of bending along the bending ruled line 2 by manual work was evaluated.
The plastic sheets 1 of Example 1 and Example 3 could be bent easily and smoothly along each folding ruled line 2 without feeling the repulsive force of the sheet. In the plastic sheet 2 of Example 2, the repulsive force of the sheet was slightly felt during the bending operation.
Next, with respect to the plastic sheet 1 formed in each embodiment, an operation for folding both side portions along a long side folding ruled line 2 that divides the side surface portion 1c and the rear surface portion 1c, and an unfolding operation that opens 180 degrees therefrom. The durability of the folded ruled line 2 was evaluated.
Although the plastic sheet 1 of Example 1 and Example 2 did not break or break the sheet even when the above operation was repeated several tens of times, the plastic sheet 1 of Example 3 was bent and creased 2 when the above operation was repeated. Cracking occurred.
Moreover, when the plastic sheet 1 formed in each Example was bent along each folding ruled line 2 and assembled into the form of the container shown in FIG. 2, the plastic sheets 1 of Example 1 and Example 3 were assembled. In the container, however, the corner of the container was clean and the appearance was good. On the other hand, in the container in which the plastic sheet 1 of Example 2 was assembled, it was confirmed that the row of the convex portions 3 forming the rope pattern in the folded ruled line 2 was thinly whitened along the corner portion of the container. .
As a result of the evaluation, it was confirmed that, in each example, the plastic sheet 1 of Example 1 was excellent in bendability and durability, and the appearance when the container was assembled was also good.

The present invention is not limited to the configuration of the illustrated embodiment.
For example, a plurality of the bent ruled lines 2 may be formed parallel to the bent portion of the plastic sheet 1. Further, the folding ruled line 2 may be attached to a plastic sheet constituting various containers such as a pillow type packaging container or a substantially triangular shape or a substantially elliptical shape, for example, only on the plastic sheet assembled in the illustrated container form. The application is not limited. The arrangement of the convex portions 3 and the blade portions 5 is not limited to the arrangement in the form shown in the drawing, and the convex portions 3 and the blade portions as long as the dimensions are included in the predetermined angle and the predetermined range. The depth, height, width, length, angle, curvature radius, etc. of 5 may be changed for each pitch.

DESCRIPTION OF SYMBOLS 1 Plastic sheet, 2 Bending ruled line, 2b Bottom surface part, 3 Convex part, 4 Ruled line blade, 4b Top surface part, 5 Blade part, 6 Cutting means

Claims (6)

A plastic sheet having a concave bent ruled line on the surface,
The concave bent ruled line is formed with both side surface portions facing each other that are inclined while being curved, and a bottom surface portion that is continuous with one end side of both side surface portions,
The bottom surface portion includes protrusions that are raised from the surface of the bottom surface portion and extend in a direction inclined by a predetermined angle with respect to the attaching direction of the bent ruled line, and a cross section between adjacent protrusions is formed. A plastic sheet with a bent ruled line, having a configuration provided in a cross-sectional shape that is continuously curved with the both side surface portions.   2. The plastic sheet with a bent ruled line according to claim 1, wherein the convex part is inclined by approximately 10 to 90 [deg.] With respect to the ruled line attaching direction.   The plastic sheet with a bent ruled line according to claim 2, wherein the convex part is inclined by approximately 15 ° with respect to the direction in which the ruled line is provided.   The plastic sheet with a folded ruled line according to any one of claims 1 to 3, wherein the bent ruled line has a configuration in which convex portions are provided at a width of 80% or more of the ruled line width dimension of the surface of the folded ruled line. A plastic sheet ruled line blade that is used when a concave bent ruled line is attached to a bent part of a plastic sheet, and the tip part is provided in a curved cross-sectional shape,
Concave blades extending in a direction inclined at a predetermined angle with respect to the direction in which the bent ruled line is attached are arranged on the top surface of the front end of the ruled line blade, and on both sides of the concave blade part at the front end of the ruled line blade. A ruled line blade for a plastic sheet having a configuration in which a curved surface is provided . Packaging container assembled with a bent ruled plastic sheet according to claim 1, 2, 3 or 4.

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