JP2023117441A - folding structure - Google Patents

Abstract

To form a three dimensional shape from a two dimensional sheet shape by controlling a folding angle to be self-folded.SOLUTION: A folding structure includes a set of: a substrate being shrinkable; an ink layer formed on a first face of the substrate; and an ink layer formed on a second face on an opposite side of the first face of the substrate interposing a fold area to be folded and separated in a ridge-like manner or in a valley-like manner at a prescribed folding angle. The set is continuously formed with the fold area connected in a plane view. The fold area exposes the substrate and a prescribed folding angle is adjustable by changing a width of the fold area.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to folding structures and folding structures, and more particularly to structures that self-fold upon chemical stimulation or heat.

A plastic origami having a plastic film and a colored layer, and having a folding retention angle of 80 degrees or less after being stored in an environment of 20°C for 24 hours. A plastic origami paper having a shrinkage ratio of 25% or more and 55% or less in both the shrinkage direction and the direction perpendicular to the main shrinkage direction is known (Patent Document 1).

A base film made of a foldable resin or metal that can form folds and maintain a bending angle, and a thermochromic ink that changes color according to temperature, and is provided on one side of the base film. Origami with layers is also known (Patent Document 2).

JP 2019-165833 A JP 2015-208376 A

The present invention creates a three-dimensional shape from a two-dimensional sheet shape by controlling the self-folding folding angle.

In order to solve the above problems, the folding structure according to claim 1 is
a shrinkable substrate;
The ink layer formed on the first surface of the base material and the second surface of the base material opposite to the first surface are spaced apart from each other with a crease region that is mountain-folded or valley-folded at a predetermined folding angle. The ink layer formed by the
It is characterized by

The invention according to claim 2 is the folding structure according to claim 1,
wherein the fold area exposes the substrate;
It is characterized by

The invention according to claim 3 is the folding structure according to claim 2,
The predetermined fold angle is adjustable by changing the width of the fold area.
It is characterized by

The invention according to claim 4 is the folding structure according to claim 3,
The predetermined folding angle and the width of the folding region have a linear relationship,
It is characterized by

The invention according to claim 5 is the folding structure according to claim 1,
An ink layer having a concentration, density, or number of layers smaller than that of the ink layer is formed in the crease region.
It is characterized by

The invention according to claim 6 is the folding structure according to claim 5,
The concentration, density, or number of layers varies smoothly,
It is characterized by

The invention according to claim 7 is the folding structure according to claim 5,
the ink layer having a small concentration, density, or number of layers is formed extending entirely or partially;
It is characterized by

The invention according to claim 8 is the folding structure according to claim 7,
The ink layer with a small concentration, density, or number of layers is formed extending wholly or partially in the folding direction,
It is characterized by

The invention according to claim 9 is the folding structure according to claim 7,
The ink layer with a low concentration, density, or number of layers is formed extending wholly or partially along a direction intersecting the folding direction,
It is characterized by

The invention according to claim 10 is the folding structure according to claim 5,
The fold area is formed by extending the ink layer in a broken line,
It is characterized by

The invention according to claim 11 is the folding structure according to claim 5,
The fold region is formed by extending the ink layer in a discrete pattern along a direction intersecting the folding direction.
It is characterized by

The invention according to claim 12 is the folding structure according to claim 1,
An ink layer having a hardness different from that of the ink layer is formed in the fold area.
It is characterized by

The invention according to claim 13 is the folding structure according to any one of claims 1 to 12,
An ink layer is formed in the fold area to cover the exposed substrate.
It is characterized by

The invention according to claim 14 is the folding structure according to any one of claims 1 to 13,
An ink layer harder than the ink layer is formed on the surface of the ink layer except for the area corresponding to the fold area.
It is characterized by

The invention according to claim 15 is the folding structure according to any one of claims 1 to 14,
The ink layer is formed with a decorative layer containing a plurality of types of process color inks.
It is characterized by

The invention according to claim 16 is the folding structure according to any one of claims 1 to 15,
The ink layer is laminated by an inkjet method,
It is characterized by

In order to solve the above problems, the folding structure according to claim 17 is
Self-folding by applying a chemical stimulus to the fold region or the entire fold structure of the fold structure according to any one of claims 1 to 16,
It is characterized by

In order to solve the above problems, the folding structure according to claim 18 is
Self-folding by heating the folding structure according to any one of claims 1 to 16,
It is characterized by

According to the first aspect of the present invention, the fold area is self-folded, so that the two-dimensional sheet shape can be made into a three-dimensional shape.

According to the second aspect of the invention, the folding can be self-folded in the fold area.

According to the third aspect of the invention, the folding angle of self-folding can be controlled.

According to the fourth aspect of the invention, the folding angle of self-folding can be controlled.

According to the fifth aspect of the invention, the folding angle of self-folding can be controlled by changing the density of the ink layer.

According to the sixth aspect of the present invention, it is possible to reduce the load on the ink layer formed in the fold area during self-folding.

According to the seventh aspect of the invention, the folding angle of self-folding can be controlled by continuously or discretely changing the concentration, density, or the number of layers of the ink layer in the folding region.

According to the eighth aspect of the invention, the folding angle of self-folding can be controlled by continuously or discretely changing the ink layer concentration, density, or the number of layers in the folding direction.

According to the ninth aspect of the invention, the self-folding folding angle is controlled by continuously or discretely changing the ink layer concentration, density, or the number of layers along the direction intersecting the folding direction. can be done.

According to the tenth aspect of the invention, the folding angle of self-folding can be controlled by changing the density of the broken lines.

According to the eleventh aspect of the invention, the folding angle of self-folding can be controlled by changing the pattern.

According to the twelfth aspect of the invention, the folding angle of self-folding can be controlled by changing the hardness of the ink layer.

According to the thirteenth aspect of the invention, damage to the shrinking base material can be suppressed.

According to the fourteenth aspect of the present invention, it is possible to protect the ink layer and suppress deformation of the regions other than the crease region.

According to the fifteenth aspect of the invention, full-color printing and decoration such as structural colors can be performed.

According to the sixteenth aspect of the invention, the folding structure can be obtained at low cost.

According to the seventeenth aspect of the invention, a three-dimensional folded structure can be obtained by chemically stimulating the entire folded structure.

According to the eighteenth aspect of the invention, a three-dimensional folded structure can be obtained by heating the folded structure.

It is a figure which shows an example of the folding structure which concerns on this embodiment. It is an enlarged cross-sectional schematic diagram which shows the cross-sectional structure of a part of folding structure shown in FIG. It is a cross-sectional schematic diagram which shows an example of multilayering in the case of making a printing ink layer into a full color. (a) is a cross-sectional schematic diagram for explaining the self-folding of the folding structure, and (b) is a cross-sectional schematic diagram showing the folding structure that is self-folded at the folding region by heating. FIG. 11 is a perspective view showing a fold region including a partial cross section of a folding structure in which a fold region is formed according to Modification 1; FIG. 10A is a perspective view showing a fold region including a partial cross section of a folding structure in which the fold region is formed according to Modification 2, and (a) is an ink formed extending wholly or partially in the folding direction; 6(b) is a perspective view showing an example of a layer, and 6(b) is a perspective view showing an example of an ink layer formed extending wholly or partially along the direction intersecting the folding direction. FIG. 12A is a perspective view showing a fold region including a partial cross section of a folding structure in which a fold region is formed according to Modification 3, and FIG. FIG. (b) is a perspective view showing an example of an ink layer extending so that the density of the dashed lines is high. FIG. 12A is a perspective view showing the fold region including a partial cross section of the folding structure in which the fold region is formed according to Modification 4, and FIG. , (b) is a perspective view showing an example of an ink layer in which a pattern extends densely. It is a cross-sectional schematic diagram which shows as a model the folding structure which self-folds in a fold|fold area|region. FIG. 10 is a diagram showing the results of measuring folding angles when self-folding is performed by changing the width of the folding line region; It is a perspective view which shows an example of a folding structure.

Next, specific examples of embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments.
It should be noted that in the following description using the drawings, the drawings are schematic, and the ratio of each dimension is different from the actual one. Illustrations other than members are omitted as appropriate.

(1) Overall Configuration of Folding Structure FIG. 1 is a diagram showing an example of the folding structure according to the present embodiment, FIG. 1 is a perspective view showing an example of a folding structure 10; FIG.
Hereinafter, the configuration of the folding structure according to this embodiment will be described with reference to the drawings.

The folding structure 1 according to this embodiment includes a shrinkable substrate 2, a printed ink layer 3 formed on a first surface 2a of the substrate 2, and a second fold on the opposite side of the substrate 2 from the first surface 2a. The printed ink layer 3 formed on the second surface 2b with a space therebetween with the fold region 4 folded at a predetermined fold angle θ between the fold regions 4 forms a pair, and the fold regions 4 are connected in a plan view. It is a two-dimensional sheet body that is repeatedly formed by

The folding structure 1 configured in this manner is exposed to visible light, infrared light, acid, or other chemical stimulation to the entire folding structure 1, or, for example, the folding structure 1 is immersed in hot water from 70°C. By heating at 100° C., a self-folded three-dimensional folded structure 10 as shown in FIG. 11 can be obtained.

(1-1) Base material The base material 2 may be any material that shrinks a certain amount by chemical stimulation or heating at 70°C to 100°C. Polyethylene sheets or polypropylene sheets are preferably used. If the thickness of the base material 2 is less than 10 μm, the stiffness required for a two-dimensional sheet body cannot be obtained, and if the thickness exceeds 100 μm, it may be difficult to self-fold the folding structure.
In this embodiment, as the base material 2, a Vilene iron-shrink sheet (thickness: 85 μm, shrinkage rate: 30%), HAKKO shrink film (thickness: 15 μm, shrinkage rate: 5.9%), etc., which are polyethylene fabrics, are used.

(1-2) Ink layer In the folding structure 1 of the present embodiment, as shown in FIG. A printing ink layer 3 that is a layer of printing ink (printing ink) for drawing is formed through an adhesive ink layer 31 that is a layer of adhesive ink (adhesive ink). In addition, a protective ink layer 32 that is a layer of ink harder than the printing ink is formed on the surface of the printing ink layer 3 .

The printing ink is a pigment-based ink. Also, the printing ink is a solvent UV ink. That is, the printing ink is obtained by diluting a UV-curable resin (ultraviolet-curable resin) that is cured by being irradiated with ultraviolet rays with an organic solvent. This printing ink is a soft ink that does not cause cracks or cracks in the printing ink layer 3 even when the printing ink layer 3 is stretched by 140%. 150”, “LUS-170”, and “LUS-200”.

The printing ink is colored in a color different from the color of the surface of the substrate 2 . In addition, the printing ink contains a plurality of types of process color inks for drawing an image on the surface of the substrate 2 . The UV curable resin contained in the printing ink is, for example, one of the types that are cured by radical polymerization or cationic polymerization, or a mixture thereof.

The adhesive ink is a solvent UV ink for adhering the printing ink layer 3 to the substrate 2 . This adhesive ink is a soft ink that does not cause cracks or cracks in the adhesive ink layer 31 even when the adhesive ink layer 31 is stretched by 140%. 200” diluted with an organic solvent. Also, the adhesive ink is a translucent ink. Note that the adhesive ink may be colored in the same color as the surface of the substrate 2 . Also, the UV curable resin contained in the adhesive ink is, for example, one of the types that are cured by radical polymerization or cationic polymerization, or a mixture thereof.

The protective ink layer 32 has hardness in the ink film after UV curing, and has high abrasion resistance and chemical resistance, protects the printing ink layer 3, and enhances the design by giving the printing ink layer 3 a glossy feeling. For example, a UV ink specified by the model number “LH-100” manufactured by Mimaki Engineering Co., Ltd. can be mentioned.
As shown in FIG. 2, the protective ink layer 32 is applied to the printed ink layer 3 formed on the first surface 2a of the base material 2 in a region corresponding to the crease region 4 that self-folds, such as by folding or bending. Deformation of the area other than the crease area 4 is suppressed by being formed except for the .

Such an ink layer consists of a printed ink layer 3 formed on the first side 2a of the substrate 2 and a second side 2b opposite the first side 2a of the substrate 2 with the crease region 4 interposed therebetween. A set of printing ink layers 3 formed at intervals is repeatedly formed so that fold regions 4 are formed on the first surface 2a and the second surface 2b of the base material 2 and are connected in a plan view.

(1-3) Formation of ink layer Such an ink layer is formed by ejecting ink from the print head of an inkjet printer arranged above the substrate 2 and applying the ink onto the substrate 2. be done.
When forming the printing ink layer 3, first, the adhesive ink is ejected to form the adhesive ink layer 31 on the first surface 2a or the second surface 2b of the substrate 2 (adhesive ink application step).
In the adhesive ink application step, the adhesive ink is applied so as to cover the entire region where the printing ink layer 3 is to be formed. Thereafter, the applied adhesive ink is irradiated with ultraviolet rays from, for example, an LED light source to cure the adhesive ink.

Next, the printing ink is discharged onto the first surface 2a or the second surface 2b of the substrate 2 on which the adhesive ink layer 31 is formed, and the printing ink is applied onto the first surface 2a or the second surface 2b of the substrate 2. Layer 3 is formed (printing ink application step). In the printing ink application step, the printing ink is cured by irradiating ultraviolet rays while the printing ink is being discharged.
Then, a protective ink layer 32 is formed on the surface of the hardened printing ink layer 3 . Here, the protective ink layer 32 is not formed in the area corresponding to the crease area 4 formed on the substrate 2 .

The printing ink layer 3 formed in this manner is formed in multiple layers as required. As for the number of layers of the printed ink layer 3, if it is too small, the shrinkage of the base material 2 cannot be sufficiently inhibited when it self-folds (deforms) at the crease region 4, and a large folding angle cannot be obtained. On the other hand, if the number of layers is too large, the printing time increases, the accuracy of the folding angle decreases, and the thickness of the printed ink layer 3 interferes with self-folding, which may limit the folding angle. . In this embodiment, black (K) ink is used as the printing ink to form the five printing ink layers 3 .

FIG. 3 shows an example of multi-layering when the printing ink layer 3 is full color. As shown in FIG. 3, a base layer 33 is formed using white ink on the surface of the printing ink layer 3 formed in multiple layers with black ink, and CMYK (C: cyan, M: magenta, Y: yellow) is formed thereon. , K: black), the full-color layer 34 is formed by irradiating ultraviolet rays and curing the process color ink while ejecting it. Incidentally, the white ink and the process color ink may be discharged at the same time. Then, if necessary, a protective ink layer 32 is formed on the surface.

(1-3) Folding area FIG. 4(a) is a cross-sectional schematic diagram explaining the self-folding of the folding structure 1, and (b) is a cross-sectional schematic diagram showing the folding structure 1 self-folding at the folding area 4 by heating. be.
The fold region 4 is a region where the printed ink layer 3 is not formed on the surface of the substrate 2 (the first surface 2a and the second surface 2b on the opposite side), and at least a part of the surface of the substrate 2 is exposed to the outside. exposed to
The printing ink layer 3 is formed in multiple layers on the first surface 2a of the base material 2 via the adhesive ink layer 31, and the printing ink layer 3 formed in multiple layers is formed on the second surface 2b of the base material 2. A fold area 4 is formed as an area where the printing ink layer 3 is not formed.

When heat is applied to the entire folding structure 1, as shown in FIG. In the region where the printed ink layer 3 is formed, the printed ink layer 3 inhibits the shrinkage of the base material 2, and only the crease region 4 where the printed ink layer 3 is not formed shrinks, as shown in FIG. 4(b). , a valley fold (indicated by V1 in FIG. 4(b)) and a mountain fold (indicated by V2 in FIG. 4(b)) at the crease region 4 (self-folding).

"Modification 1"
FIG. 5 is a perspective view showing the fold region 4A including a partial cross section of the folding structure 1A in which the fold region 4A according to Modification 1 is formed.
An ink layer 41 having a density, density, or number of layers smaller than that of the printed ink layer 3 is formed in the crease region 4A according to Modification 1. As shown in FIG.

As the ink forming the ink layer 41 , pigment-based solvent UV ink having a lower concentration than the printing ink forming the printing ink layer 3 can be used. Examples of low-density inks include model numbers "LUS-120", "LUS-150", "LUS-170", and "LUS-200" manufactured by Mimaki Engineering Co., Ltd., which are used as printing inks. For example, the UV ink is diluted with an organic solvent to a low concentration.
Further, the ink layer 41 may be printed by using the same ink as the printing ink forming the printing ink layer 3 and reducing the density of droplets ejected from the print head. It may be formed so that the height is smaller than that of the printing ink layer 3 by reducing the number of layers. Also, concentration, density, and number of layers may be changed singly or in combination.

The ink layer 41 may be formed so as to change gently. The ink layer 41 whose density, density, or number of layers changes smoothly is formed by controlling the ejection of a print head that ejects ink droplets.
By gently changing the concentration, density, or the number of layers of the ink layer 41 formed in the fold area 4A, the load on the ink layer 41 during self-folding can be reduced, and self-folding can be facilitated.

When such a folded structure 1A in which the ink layer 41 having a density, density, or number of layers smaller than that of the printed ink layer 3 is formed in the fold region 4A is heated, the shrinkage of the fold region 4A is partially inhibited by the ink layer 41. By adjusting the concentration, density, or the number of layers of the ink layer 41, the folding angle of the self-folding of the folding region 4A can be controlled.

Moreover, the ink layer 41 may be formed using an ink having a hardness different from that of the printing ink layer 3 . Inks having different hardnesses can be made to have different hardnesses when cured and fixed to the substrate 2 by appropriately selecting binder resins and pigments.
If the hardness of the ink layer 41 is increased, the folding angle of self-folding in the fold area 4A becomes small, and if the hardness of the ink layer 41 is decreased, the folding angle of self-folding becomes large. can control the self-folding folding angle of the folding region 4A.

"Modification 2"
FIG. 6 is a perspective view showing the fold region 4B including a partial cross section of the folding structure 1B in which the fold region 4B according to Modification 2 is formed.
An ink layer 41 having a density, density, or number of layers smaller than that of the printed ink layer 3 is formed extending entirely or partially in the crease region 4B according to Modification 2. FIG. Here, as schematically shown in FIG. 6(a), the ink layer 41 may be formed so as to extend entirely or partially in the folding direction (the X direction in the figure). ), it may be formed so as to extend wholly or partially along the direction intersecting the folding direction (the Y direction in the figure).

Such an ink layer 41 that extends wholly or partially and has a small density, density, or a small number of layers is formed by performing ejection control of a print head that ejects ink droplets.
The folding angle of self-folding can be controlled by continuously or discretely changing the concentration, density, or the number of layers of the ink layer 41 in the folding region 4B.

"Modification 3"
FIG. 7 is a perspective view showing the fold region 4C including a partial cross section of the folding structure 1C in which the fold region 4C according to Modification 3 is formed.
In the crease region 4</b>C according to Modification 3, an ink layer 41 having a density, density, or number of layers smaller than that of the printed ink layer 3 is formed extending in a broken line shape.

FIG. 7A shows an example of the ink layer 41 extending so that the density of the dashed lines is low, and FIG. 7B shows an example of the ink layer 41 extending so that the density of the dashed lines is high.
By controlling the ejection of the print head that ejects the ink droplets, the ink layer 41 formed in the fold area 4C can be formed in the shape of a broken line. By adjusting the dashed line density of the formed ink layer 41, the folding angle of the self-folding of the folding region 4C can be controlled.

"Modification 4"
FIG. 8 is a perspective view showing the fold region 4D including a partial cross section of the folding structure 1D in which the fold region 4D according to Modification 4 is formed.
In the crease region 4</b>D according to Modification 4, an ink layer 41 having a density, density, or number of layers smaller than that of the print ink layer 3 is formed extending in a discrete pattern.

FIG. 8(a) shows an example of an ink layer 41 in which the pattern extends sparsely, and FIG. 8(b) shows an example of the ink layer 41 in which the pattern extends densely.
The ink layer 41 formed in the fold area 4D can be formed as a discrete pattern by controlling the ejection of the print head that ejects the ink droplets. By adjusting the pattern of the formed ink layer 41, the folding angle of the self-folding of the folding region 4D can be controlled.

(2) Self-Folding FIG. 9 is a schematic cross-sectional view showing a folding structure 1 that self-folds at the fold area 4 as a model.
In the folding structure 1 according to the present embodiment, by applying a chemical stimulus or heat to the entire folding structure 1, the fold region 4 is mountain-folded or valley-folded at a predetermined folding angle θ. At this time, the folding angle θ and the width W of the folding region 4 have a proportional relationship, particularly a linear relationship, and the folding angle θ can be adjusted by changing the width W of the folding region 4 .

In FIG. 9, the fold angle θ and the width W of the fold area 4 are formulated by the formula (1).
θ=(180×ε/π×t)×W (1)
where ε is the shrinkage rate of the substrate 2, t is the thickness of the substrate 2, and W is the width of the fold area.

"Example"
FIG. 10 is a diagram showing the results of measuring the fold angle θ when the fold area 4 is self-folded while changing the width W of the fold area 4 .
In the examples, an A5 size (210 mm × 148 mm) Vilene iron-shrinkable sheet (thickness: 85 µm, shrinkage rate: 30%) and HAKKO shrink film (thickness: 15 µm, shrinkage rate: 5.9%) were prepared as the base material 2. A plurality of fold regions 4 extending in the short side direction with a width W of . Then, the folding structure 1A in which the width W of the fold area 4 was changed in the range of 0.1 mm to 0.8 mm was heated and self-folded for each base material 2, and the folding angle θ was measured. Self-folding was repeated with eight samples for the width W of each textured region 4, and the standard deviation of the fold angle θ was also confirmed.

FIG. 10(a) shows the fold angle θ measured with respect to the width W of the fold region 4 of the self-folding structure 1A using the Vilene iron-shrinkable sheet (thickness 85 μm, shrinkage rate 30%) as the base material 2. , and FIG. 10(b) shows the fold angle θ measured with respect to the width W of the fold region 4 of the self-folding structure 1A using a HAKKO shrink film (thickness: 15 μm, shrinkage rate: 5.9%) as the base material 2. is shown.

As shown in the plots of FIGS. 10(a) and 10(b), a strong linearity was confirmed in the width W and the folding angle θ of the fold region 4 for both substrates 2 (coefficient of determination R ² >0.98). Moreover, the standard deviation was 6°/mm for the Vilene iron shrink sheet and 9°/mm for the HAKKO shrink film for any width W of the crease region 4, confirming that the folding angle θ was controlled with high accuracy. was done.

The inclination of the fold angle θ with respect to the width W of the fold area 4 was θ/W=203 for the Vilene iron-shrink sheet and θ/W=204 for the HAKKO shrink film.
Here, if the thickness t and the shrinkage rate ε of the Vilene iron-shrink sheet and the HAKKO shrink film are substituted into the equation (1) that formulates the relationship between the folding angle θ and the width W of the fold area 4, the Vilene iron-shrink sheet yields θ/ W = 202, θ/W = 225 for the HAKKO shrink film, and when compared with the inclination of the folding angle θ with respect to the width W of the folding region 4 confirmed in the example, the relationship between the folding angle θ and the width W of the folding region 4 It was confirmed that the formula (1) formulating is suitable as a model for estimating the fold angle θ.

In the folding structure 1 of this embodiment, the folding angle θ and the width W of the fold region 4 have a linear relationship, and by changing the width W of the fold region 4, the deformation into a three-dimensional shape is controlled with high accuracy. be able to.
Further, by forming an ink layer 41 having a density, density, or number of layers smaller than that of the printing ink layer 3 in the crease region 4, and adjusting the density, density, or number of layers of the ink layer 41, the self-folding folding angle θ can be controlled.
In particular, the ink layer 41 is laminated by an inkjet method, and by controlling the discharge of the print head, it is possible to laminate so that the density, density, or the number of layers changes gently, and the ink layer 41 when self-folding. It is possible to control the folding angle θ of the self-folding while reducing the load of .

1, 1A, 1B, 1C, 1D... folding structure 2... base material, 2a... first surface, 2b... second surface 3... printing ink layer, 31... adhesive ink layer, 32... protective ink layer,
33... Base layer, 34... Full color layer 4, 4A, 4B, 4C, 4D... Crease area 41... Ink layer

In order to solve the above problems, the folding structure according to claim 1 is
A folding structure capable of forming a three-dimensional folded structure by being self-folded,
A first ink layer formed on a predetermined area on the first surface of a shrinkable substrate, and a second surface of the substrate opposite to the first surface corresponding to the predetermined area at a predetermined folding angle. A second ink layer formed separately with the fold area sandwiched therebetween is paired, and the fold area is connected in plan view and repeatedly formed,
An ink layer having a concentration, density, or number of layers smaller than that of the first ink layer and the second ink layer is formed in the crease region.
It is characterized by

The invention according to claim 2 is the folding structure according to claim 1 ,
The concentration, density, or number of layers varies smoothly,
It is characterized by

The invention according to claim 3 is the folding structure according to claim 1 ,
the ink layer having a small concentration, density, or number of layers is formed extending entirely or partially;
It is characterized by

The invention according to claim 4 is the folding structure according to claim 3 ,
The ink layer with a low concentration, density, or number of layers is formed so as to extend wholly or partially in a direction intersecting with the direction in which the fold region extends ,
It is characterized by

The invention according to claim 5 is the folding structure according to claim 3 ,
The ink layer having a low concentration, density, or number of layers is formed to extend wholly or partially along the direction in which the fold region extends .
It is characterized by

The invention according to claim 6 is the folding structure according to claim 1 ,
The crease region is formed by extending the ink layer with a small density, density, or number of layers in a broken line.
It is characterized by

The invention according to claim 7 is the folding structure according to claim 1 ,
The crease region is formed such that the ink layer having a low density, density, or number of layers extends in a discrete pattern along a direction intersecting the direction in which the crease region extends .
It is characterized by

The invention according to claim 8 is the folding structure according to claim 1,
An ink layer having a hardness different from that of the first ink layer and the second ink layer is formed in the crease region.
It is characterized by

The invention according to claim 9 is the folding structure according to any one of claims 1 to 8 ,
An ink layer that is harder than the first ink layer and the second ink layer is formed on the surfaces of the first ink layer and the second ink layer except for the area corresponding to the crease area. ,
It is characterized by

The invention according to claim 10 is the folding structure according to any one of claims 1 to 9 ,
The first ink layer and the second ink layer are formed with a decorative layer containing a plurality of types of process color inks.
It is characterized by

The invention according to claim 11 is the folding structure according to any one of claims 1 to 10 ,
The first ink layer , the second ink layer, and the ink layer with a small concentration, density, or number of layers are laminated by an inkjet method,
It is characterized by

According to the second aspect of the invention, it is possible to reduce the load on the ink layer formed in the fold area during self-folding.

According to the third aspect of the invention, the folding angle of self-folding can be controlled by continuously or discretely changing the concentration, density, or the number of layers of the ink layer in the folding region.

According to the fourth aspect of the invention, the folding angle of self-folding can be controlled by continuously or discretely changing the concentration, density, or the number of layers of the ink layer in the folding direction.

According to the fifth aspect of the invention, the self-folding folding angle is controlled by continuously or discretely changing the ink layer concentration, density, or the number of layers along the direction intersecting the folding direction. can be done.

According to the sixth aspect of the invention, the folding angle of self-folding can be controlled by changing the density of the broken lines.

According to the seventh aspect of the invention, the folding angle of self-folding can be controlled by changing the pattern.

According to the eighth aspect of the invention, the folding angle of self-folding can be controlled by changing the hardness of the ink layer.

According to the ninth aspect of the present invention, it is possible to protect the ink layer and suppress deformation of the region other than the crease region.

According to the tenth aspect of the invention, full-color printing and decoration such as structural colors can be performed.

According to the invention of claim 11 , the folding structure can be obtained at low cost.

TECHNICAL FIELD The present invention relates to a folding structure, and more particularly to a structure that self-folds under chemical stimulation or heat.

Claims (18)

a shrinkable substrate;
The ink layer formed on the first surface of the base material and the second surface of the base material opposite to the first surface are spaced apart from each other with a crease region that is mountain-folded or valley-folded at a predetermined folding angle. The ink layer formed by the
A folding structure characterized by: wherein the fold area exposes the substrate;
The folding structure according to claim 1, characterized in that: The predetermined fold angle is adjustable by changing the width of the fold area.
The folding structure according to claim 2, characterized in that: The predetermined folding angle and the width of the folding region have a linear relationship,
The folding structure according to claim 3, characterized in that: An ink layer having a concentration, density, or number of layers smaller than that of the ink layer is formed in the crease region.
The folding structure according to claim 1, characterized in that: The concentration, density, or number of layers varies smoothly,
The folding structure according to claim 5, characterized in that: the ink layer having a small concentration, density, or number of layers is formed extending entirely or partially;
The folding structure according to claim 5, characterized in that: The ink layer with a small concentration, density, or number of layers is formed extending wholly or partially in the folding direction,
The folding structure according to claim 7, characterized in that: The ink layer with a low concentration, density, or number of layers is formed extending wholly or partially along a direction intersecting the folding direction,
The folding structure according to claim 7, characterized in that: The fold area is formed by extending the ink layer in a broken line,
The folding structure according to claim 5, characterized in that: The fold region is formed by extending the ink layer in a discrete pattern along a direction intersecting the folding direction.
The folding structure according to claim 5, characterized in that: An ink layer having a hardness different from that of the ink layer is formed in the fold area.
The folding structure according to claim 1, characterized in that: An ink layer is formed in the fold area to cover the exposed substrate.
13. The folding structure according to any one of claims 1 to 12, characterized in that: An ink layer harder than the ink layer is formed on the surface of the ink layer except for the area corresponding to the fold area.
14. The folding structure according to any one of claims 1 to 13, characterized in that: The ink layer is formed with a decorative layer containing a plurality of types of process color inks.
15. The folding structure according to any one of claims 1 to 14, characterized in that: The ink layer is laminated by an inkjet method,
16. The folding structure according to any one of claims 1 to 15, characterized in that: Self-folding by applying a chemical stimulus to the fold region or the entire fold structure of the fold structure according to any one of claims 1 to 16,
A folding structure characterized by: Self-folding by heating the folding structure according to any one of claims 1 to 16,
A folding structure characterized by:

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