JP6839018B2 - Calculation system, calculation method, and winding method - Google Patents

Description

The present invention, calculation system, calculation method, and relates to a winding method.

Conventionally, in a capacitive touch panel, a glass plate or an acrylic plate as a top plate is usually laminated on the visible side of the conductive pattern layer via a hard coat film. At this time, in order to bond the hard coat film to the conductive pattern layer or the like, an adhesive layer is provided only on the outer peripheral portion of the laminated surface from the viewpoint of reworkability and ease of bonding, and the hard coat film and the conductive pattern layer are bonded. An air gap is often formed between the layers. When such an air gap causes a difference in refractive index between the hard coat film and the conductive pattern layer, the brightness and contrast are lowered due to light scattering, and the visibility of the screen is likely to be lowered. It was seen. Therefore, there is a technique of providing a thick film layer made of an optical transparent adhesive on the entire surface of the laminated surface of the hard coat film and the conductive pattern layer. According to Patent Document 1, even when a thick pressure-sensitive adhesive layer is formed, a pressure-sensitive adhesive layer having excellent uniformity of component distribution can be stably obtained. This makes it possible to effectively suppress the local concentration of stress in the pressure-sensitive adhesive layer, and by extension, a solvent-free pressure-sensitive adhesive composition capable of stably obtaining a pressure-sensitive adhesive layer having excellent blister resistance. A pressure-sensitive adhesive obtained by curing the pressure-sensitive adhesive and a method for producing the pressure-sensitive adhesive are disclosed.

Japanese Unexamined Patent Publication No. 2015-193842

By the way, the thick film layer composed of such an adhesive layer (hereinafter referred to as "adhesive layer") is a product in the form of a long sheet (hereinafter referred to as "sheet") sandwiched between the release layers. It is often converted. By sandwiching the adhesive layer between the release layers, the quality of the adhesive layer can be maintained. Further, in general, a sheet product is wound around a tubular winding core or the like along the longitudinal direction of the sheet, and is stored in the form of a winding roll body having a substantially cylindrical shape. As a result, the space required for storing the sheet can be kept compact. In addition, the sheet is conveyed in the form of a take-up roll body. As a result, the place required for transportation can be kept compact, and at the transportation destination, the wound sheet can be pulled out as much as necessary for processing or use, which facilitates handling. In this way, the sheet can be handled efficiently by storing or transporting the sheet in the form of a take-up roll body. However, in the sheet as described above, due to the increased film thickness, wrinkles are likely to occur in the sheet when the sheet is wound around the winding core in the production of the winding roll body, and once wrinkles occur, the sheet product The quality of the product may be significantly impaired.

Some aspects of the present invention provide a calculation system and a calculation method capable of calculating the degree of wrinkles generated when a sheet is bent, and wrinkles calculated using the calculation system and the calculation method. It is an object of the present invention to provide a winding method for winding a sheet so that wrinkles do not occur on the sheet in consideration of the degree of occurrence of the sheet.

In order to solve the above-mentioned problems, the calculation system according to the embodiment of the present invention has a long web formed by three layers in which an inner layer, an intermediate layer, and an outer layer are laminated in this order, and the web is formed into a columnar shape. This is a calculation system that calculates the degree of wrinkles in the inner layer, which is the inside of bending when the roller is held on the body surface of the roller, as the degree of wrinkles. The calculation system is based on the Young's modulus of the inner layer and the thickness of each of the three layers, which is the wavelength of wrinkles generated in the inner layer when the web is held on the body surface of the columnar roller. The first calculation means for calculating the wavelength, the neutral axis position of the web, the thickness of the web, the thickness of the inner layer, the Young's modulus of the inner layer, and the web were held on the body surface of the columnar roller. The web is provided based on the second calculation means for calculating the bending compressive stress acting on the inner layer based on the curvature, the wrinkle wavelength, the Young's modulus of the inner layer, and the thickness of each of the three layers. Based on the third calculation means for calculating the wrinkle-generating stress, which is the compressive stress that causes wrinkles in the inner layer when the columnar roller is held on the body surface, and the bending compressive stress and the wrinkle-generating stress. A fourth calculation means for calculating the degree of wrinkle occurrence.

Further, in the above-mentioned calculation system, the first calculation means is a means for calculating the wrinkle wavelength λ shown in the formula (4) by using the formulas (1) to (4) described later, and the first calculation means. _{The 2 calculation means is a means for calculating the bending compressive stress σ r} shown in the equation (7) by using the equations (5) to (7) described later, and the third calculation means is the means for calculating the bending compressive stress σ r described later in (8). ) Is a means for calculating the wrinkle generation stress σ _cr shown in the formula (), and the fourth calculation means is a means for calculating the wrinkle occurrence degree A shown in the formula (9) described later.

Further, in the calculation method of one embodiment of the present invention, in a long web formed by three layers in which an inner layer, an intermediate layer, and an outer layer are laminated in this order, the web is held on the body surface of a columnar roller. This is a calculation method for calculating the degree of wrinkling in the inner layer, which is the inside of bending when squeezed, as the degree of wrinkling. The calculation method is based on the Young's modulus of the inner layer and the thickness of each of the three layers, which is the wavelength of wrinkles generated in the inner layer when the web is held on the body surface of the columnar roller. The first calculation step of calculating the wavelength, the neutral axis position of the web, the thickness of the web, the thickness of the inner layer, the Young's modulus of the inner layer, and the web were held on the body surface of the columnar roller. Based on the second calculation step of calculating the bending compressive stress acting on the inner layer based on the curvature, the wrinkle wavelength, the Young's modulus of the inner layer, and the thickness of each of the three layers, the web is formed. The degree of wrinkle generation is based on the third calculation step of calculating the wrinkle generation stress in which wrinkles are generated in the inner layer when the columnar roller is held on the body surface, and the bending compressive stress and the wrinkle generation stress. A fourth calculation step for calculating the above.

Further, in the winding method of one embodiment of the present invention, the wrinkle occurrence degree calculated by the above calculation system satisfies a predetermined determination criterion determined to wind the web so that the web does not have wrinkles. As described above, the design process of designing the radius of the winding core, the thickness of each of the three layers forming the web, and the Young ratio of each of the three layers forming the web, and the winding of the radius adjusted by the design process. The core is provided with a winding step of winding the web to generate a winding roll body.

According to one aspect of the present invention, the degree to which wrinkles occur when the sheet is bent can be calculated.

It is a block diagram of the calculation system 10 of an embodiment. It is a figure for demonstrating the relationship between a stiffness parameter and a wrinkle wavelength λ. It is a figure for demonstrating the neutral axis position. It is a figure for demonstrating the state of the sheet 2 when the sheet 2 is bent. It is a figure for demonstrating the wrinkle wavelength λ. It is a flowchart which shows the flow of the process performed by the calculation system 10 of an embodiment. It is a figure which shows the 1st table which corresponded with the calculation result performed by the calculation system 10 of embodiment, and the result of visually confirming the presence or absence of the occurrence of wrinkles. It is a figure which shows the 2nd table which corresponded with the calculation result performed by the calculation system 10 of embodiment, and the result of visually confirming the presence or absence of the occurrence of wrinkles.

Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the inventions that fall within the scope of the claims. Also, not all combinations of features described in the embodiments are essential to the means of solving the invention. In the drawings, the same or similar parts may be designated by the same reference numerals to omit duplicate explanations. In addition, the shape and size of elements in the drawings may be exaggerated for a clearer explanation.

When a part of the specification is to "include", "have", or "provide" a component, this does not exclude other components unless otherwise stated. It means that it can further include the components of.

Hereinafter, the calculation system 10 and the take-up roll body 3 of the embodiment will be described with reference to the drawings.

(About sheet 2)
First, the sheet 2 will be described. The sheet 2 is a long sheet composed of three layers, an outer layer, an intermediate layer, and an inner layer.

In the present embodiment, the thickness of the intermediate layer is preferably 200 to 3000 [μm], particularly preferably 250 to 1000 [μm]. The material of the outer layer and the inner layer is preferably a thermoplastic resin, but may be made of a metal foil such as iron, copper, or aluminum, or paper. Examples of the thermoplastic resin include polypropylene (PP), polyethylene (PE), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polystyrene (PS), polyimide (PI), and polycarbonate (PC). The materials of the outer layer and the inner layer may be the same material or different materials from each other. The outer layer and the inner layer may or may not be peeled from a silicone-based resin, a fluororesin, a long-chain alkyl-based resin, or the like. Further, the thicknesses of the outer layer and the inner layer are not particularly limited. The thickness of the outer layer and the inner layer may be the same as each other, or the thickness of the outer layer and the inner layer may be different from each other.
The intermediate layer may be made of the same material as the outer layer and the inner layer, or may be rubber or an adhesive. Examples of the rubber include natural rubber, isoprene rubber, styrene-butadiene rubber, butadiene rubber, chloroprene rubber, butyl rubber, nitrile rubber, ethylene propylene rubber, acrylic rubber, urethane rubber, silicone rubber, and fluororubber. Examples of the pressure-sensitive adhesive include acrylic type, silicone type, polyester type, epoxy type, urethane type, and rubber type.

FIG. 4 is a diagram for explaining a state of the sheet 2 when the sheet 2 is bent. 4 (a) and 4 (b) are views of the bent state of the sheet 2 as viewed from a cross section perpendicular to the sheet surface. As shown in FIG. 4A, the sheet 2 is formed of three layers in which the release layer 20, the adhesive layer 22, and the release layer 24 are laminated in this order. That is, the sheet 2 is formed by sandwiching the adhesive layer 22 between the release layers 20 and 24.
As shown in FIGS. 4A and 4B, the sheet 2 is bent by being wound around the winding core 1 so as to be curved along the body surface (side surface) of the cylindrical winding core 1, for example. Be done. When the sheet 2 is bent in this way, as shown in FIG. 4B, wrinkles may occur in the release layer 24 which is inside the bending of the sheet 2 when the sheet 2 is bent.

In the present specification, "bending the sheet 2" and "bending the sheet 2" mean that when a long web is held on the body surface of a columnar roller (also referred to as a winding core 1), the body surface is covered. Refers to bending along a curved surface.

In this way, the long sheet 2 formed by the three layers in which the outer layer, the intermediate layer, and the inner layer are laminated in this order is curved along the body surface of the winding core 1 so as to be held by the winding core 1. When wound around the winding core 1, wrinkles are likely to occur in the inner layer inside the winding. The calculation system 10 of the present embodiment calculates the degree of wrinkle occurrence, which indicates the degree of wrinkle occurrence. Here, Sheet 2 is an example of the "web". One of the peeling layers 20 and 24 is an example of the "outer layer", and the other is an example of the "inner layer". The adhesive layer 22 is an example of an “intermediate layer”. In the following description, when the sheet 2 is wound around the winding core 1, the release layer 24 will be described as an inner layer that comes inside.

(About calculation system 10)
Here, the calculation system 10 will be described.
FIG. 1 is a configuration diagram of the calculation system 10 of the embodiment. As shown in FIG. 1, the calculation system 10 includes a wrinkle wavelength calculation means 11 (an example of a "first calculation means"), a bending compressive stress calculation means 12 (an example of a "second calculation means"), and a wrinkle generation stress. A calculation means 14 (an example of a "third calculation means") and a wrinkle occurrence degree calculation means 16 (an example of a "fourth calculation means") are provided.
Parameters such as the thickness of each of the three layers (peeling layers 20, 24 and the adhesive layer 22) forming the sheet 2, the Young's modulus of each, the radius of the winding core 1, and the critical value k are input to the calculation system 10. .. These parameters are input to the calculation system 10 from the external input device, for example, by the user operating an external input device (not shown). The external input device is, for example, a mouse, a keyboard, or the like.
The wrinkle wavelength calculating means 11 calculates the wavelength λ of wrinkles generated in the peeling layer 24 based on the Young's modulus of the peeling layer 24 and the thicknesses of each of the three layers of the peeling layers 20 and 24 and the adhesive layer 22. The wrinkle wavelength calculating means 11 can output the calculated wrinkle wavelength λ to the bending compressive stress calculating means 12.

The wrinkle wavelength calculating means 11 first calculates the flexural rigidity EI of the peeling layer 24. The flexural rigidity EI of the release layer 24 is represented by the following equation (1). _{Here, E in} the Young's modulus of the release layer _24, the _{t in} showing the thickness of the release layer 24.

Flexural rigidity as shown in equation (1) EI is a value obtained by multiplying the cube of the thickness t _in the peeling layer 24 to the Young's modulus E _in the release layer 24. The Young's modulus is a value determined for each material, and the Young's modulus of a easily bendable material (for example, a rubber material) is lower than that of a hard-to-bend material (for example, a glass material). Further, in the flexural rigidity EI, the width of the sheet 2 is not considered because it does not affect the occurrence of wrinkles.

Further, the wrinkle wavelength calculation means 11 next calculates the thickness ratio ν. The thickness ratio ν is expressed by the following equation (2). Here, t _mid indicates the thickness of the adhesive layer 22, and to _out indicates the thickness of the release layer 20.

As shown in the equation (2), the thickness ratio ν is a value obtained by dividing _{the thickness t mid of the adhesive layer 22 by the thickness to out} of the peeling layer 20.

Further, the wrinkle wavelength calculating means 11 calculates the rigidity parameter G. The rigidity parameter G is represented by the following equation (3). Here, the flexural rigidity EI is the value shown by the above equation (1), and the thickness ratio ν is the value shown by the above equation (2).

As shown in the equation (3), the rigidity parameter G is a value obtained by multiplying the thickness ratio ν and the flexural rigidity EI.

Then, the wrinkle wavelength calculating means 11 calculates the wrinkle wavelength (wrinkle wavelength) λ generated in the peeling layer 24. The wavelength λ of the wrinkles generated in the peeling layer 24 is represented by the following equation (4). Here, the rigidity parameter G is a value represented by the above equation (3).

As shown in Eq. (4), the wrinkle wavelength λ is a function of the stiffness parameter G.
As described above, the wrinkle wavelength calculating means 11 calculates the wavelength λ of the wrinkles generated in the peeling layer 24 based on the Young's modulus of the peeling layer 24 and the thicknesses of each of the three layers of the peeling layers 20, 24, and the adhesive layer 22. ..

In the present embodiment, the wavelength λ of the wrinkles generated inside when the sheet 2 is bent is the Young's modulus E _{in of the inner release layer 24, and the thickness (t out} , t _{mid) of} each of the three layers forming the sheet 2. It is related to _tin). Thus, wrinkles wavelength calculating unit 11 has a Young's modulus _{E in} the inner release layer 24, three layers each of thickness to form a sheet _{2 (t out, t mid,} t in) is used to calculate the wrinkles wavelength λ ..
As shown in equation (1), bending rigidity EI is proportional to the cube of the thickness _{t in} the Young's modulus _{E in,} and release layer 24 of release layer 24. Further, as shown in the equation (2), the thickness ratio ν is _{proportional to the thickness t mid} of the adhesive layer 22 and inversely proportional to the thickness to _{out of the peeling layer 20.} Further, as shown in the equation (3), the rigidity parameter G is proportional to each of the thickness ratio ν and the flexural rigidity EI. Further, as shown in Eq. (4), the wrinkle wavelength λ is a function of the rigidity parameter G.
That is, (1) to (3) as shown in equation stiffness parameter G, the thickness _{t mid} of the adhesive layer 22, the Young's modulus _{E in} the peeling layer 24, and to the cube of the thickness _{t in} the peeling layer 24, respectively Proportional. Further, the stiffness parameter G is inversely proportional to the thickness _{t out} of the release layer 20. Stiffness parameter G is adhesive layer 22, the larger the thickness of each of the release layer 24, and as the Young's modulus E _in the peeling layer 24 is high (hard deformed), a large value. Further, the stiffness parameter G, the more the thickness _{t out} of the release layer 20 is small, a large value.
On the other hand, the ^{function represented by y = x a} (a is a positive constant) is a monotonically increasing function in which y increases as x increases when x is a positive real number. That is, in the equation (4), the wrinkle wavelength λ becomes larger as the rigidity parameter G becomes larger (for example, the thickness of the adhesive layer 22 becomes larger). The Young's modulus E _in the peeling layer 24 increases, wrinkles wavelength λ increases. Further, as the thickness t _in the peeling layer 24 becomes thick, wrinkles wavelength λ increases. Further, the thinner the release layer 20, the larger the wrinkle wavelength λ.

Here, the relationship between the rigidity parameter G and the wrinkle wavelength λ will be described with reference to FIGS. 2 and 5. FIG. 2 is a diagram for explaining the relationship between the rigidity parameter G and the wrinkle wavelength λ. FIG. 5 is a diagram for explaining the wrinkle wavelength λ. In FIG. 2, the horizontal axis shows the rigidity parameter G, and the vertical axis shows the wrinkle wavelength λ. The points shown in FIG. 2 are plots of the wrinkle wavelength λ generated in each sheet 2 when the material and thickness of the sheet 2 are changed for each rigidity parameter G of the sheet 2. The curve L shown in FIG. 2 is an approximate curve obtained from the plotted point cloud.

In the present embodiment, data obtained by actually measuring the wrinkle wavelength λ is collected, and a curve L that approximates the relationship between the rigidity parameter G and the wrinkle wavelength λ indicated by the collected data is calculated. As a result, the wrinkle wavelength calculation means 11 obtains the relationship between the rigidity parameter G and the wrinkle wavelength λ from the curve L.
As shown in FIG. 5, the wrinkle wavelength indicates the wavelength of a sine wave when the shape of the cross section of the wrinkle generated in the peeling layer 24 inside the bending is regarded as a curve and this curve is used as a sine waveform. The wrinkle wavelength λ is measured by observing the cross section of the sheet 2 with, for example, a microscope or the like.
As shown by the point cloud in FIG. 2, the wrinkle wavelength λ with respect to the rigidity parameter G has a constant tendency for the wrinkle wavelength λ to increase as the rigidity parameter G increases. By showing this constant tendency with an approximate curve, the wrinkle wavelength calculation means 11 can calculate the wrinkle wavelength λ for an arbitrary rigidity parameter G. Approximate curve in the present embodiment, (4) as shown in the expression but is approximated by a power function, shown in the form of y = x ^a, is not limited to this. The approximate curve may be approximated by a linear function, an exponential function, or another function. Further, the wrinkle wavelength calculation means 11 may recalculate the approximate curve, for example, when data obtained by actually measuring the wrinkle wavelength λ is added. Further, the wrinkle wavelength calculation means 11 may be used as the wrinkle wavelength λ calculated by actually measuring the wrinkle wavelength λ generated on the calculation target sheet 2 for calculating the wrinkle wavelength λ without using the approximate curve. Good.

Returning to FIG. 1, the bending compressive stress calculating means 12 includes the neutral axis position m of the sheet 2, the thicknesses of each of the three layers of the release layers 20 and 24, and the adhesive layer 22, and the Young's modulus E _in of the release layer 24. _{The bending compressive stress σ r} is calculated based on the radius r of the winding core 1. The bending compressive stress σ _r is a force that compresses the release layer 24 generated by bending the sheet 2. Here, when a force for compressing the release layer 24 acts on the release layer 24, the force that the release layer 24 resists compression (change) may be used as a bending compressive stress, but the release layer 24 is compressed. Since the force to be compressed and the bending compressive stress are balanced, in the present embodiment, the force to compress the release layer 24 is referred to as bending compressive stress.

The bending compressive stress calculating means 12 calculates the neutral axis position m of the sheet 2.
First, the neutral axis position m will be described with reference to FIG. FIG. 3 is a diagram for explaining the neutral axis position m. When the sheet 2 is bent along the winding core 1, a force acts on the outer layer (release layer 20) of the sheet 2 in the pulling direction, while the inner layer (release layer 24) of the sheet 2 is subjected to a force. Force acts in the direction of compression. That is, when the sheet 2 is bent, a force in the opposite direction acts on the outside (release layer 20) and the inside (release layer 24) of the sheet surface. Further, on the line perpendicular to the sheet surface between the peeling layer 20 and the peeling layer 24, there is an equilibrium position of forces in which neither the pulling force nor the compressing force acts. Such a balanced position of force is called a neutral axis position m.
The neutral axis position m is represented by the following equation (5). Here, h ₁ is the thickness of the release layer 20, h ₂ is the sum of the thicknesses of the _{release layer 20 and the adhesive layer 22, and h 3} is the sum of the thicknesses of the release layer 20, the adhesive layer 22, and the release layer 24. Are shown respectively.

Further, the bending compressive stress calculating means 12 calculates the distance y'. As shown in FIG. 3, the distance y'is the distance from the neutral axis position m to the intermediate position of the peeling layer 24. It is represented by the equation (6) below the distance y'.

In the above (6), as an intermediate position of the release layer 24, is used the position of t _{in / 2} from the upper surface of the release layer 24 is not limited thereto. The intermediate position of the release layer 24 may be a position representing a position where a force in the compression direction acts on the release layer 24. Thus, for example, if a thin release layer 24 relative to the thickness of the adhesive layer 22, the formula (6) _{t in} / 2, the position indicating the boundary between the adhesive layer 22 of the release layer 24 (release layer 24 The position of the upper surface of the peeling layer 24) may be used, or the position of the bottom surface of the release layer 24 may be used.

Further, the bending compressive stress calculating means 12 calculates the bending compressive stress σ _r . The bending compressive stress σ _r is expressed by the following equation (7). Here, E _in indicates the Young's modulus of the release layer 24, y'indicates the distance from the neutral axis position m to the intermediate position of the release layer 24, and r indicates the radius of the winding core 1.

As shown in the equation (7), the bending compressive stress σ _r is proportional to the Young's modulus E _in of the peeling layer 24 and the distance y ′, and is inversely proportional to the radius r of the winding core 1.

Here, the relationship between the distance y'shown in the above equation (6) and the bending compressive stress σ _r will be described with reference to FIG. 4 (a) and 4 (b) are views of the bent state of the sheet 2 as viewed from a cross section perpendicular to the sheet surface. FIG. 4A shows an example in which the thickness of the adhesive layer 22 is smaller (thinner) than that of FIG. 4B, and FIG. 4B shows the adhesive layer 22 as compared with FIG. 4A. Examples of cases where the thickness of is large (thick) are shown.

As shown in FIG. 4A, when the sheet 2 is bent, the peeling layer 24 inside the bending has a force for compressing the peeling layer 24, bending compressive stresses σ _r -1, σ _r −. 2 works. In the following description, when the bending compressive stress σ _r -1 and σ _r -2 are not particularly distinguished, it is simply referred to as “bending compressive stress σ _r ”.
The magnitude of the bending compressive stress σ _r of the release layer 24 is proportional to the amount of compression of the release layer 24 (strain amount ε) in the elastic range (the range in which the release layer 24 returns to its original state even if it is deformed by tension or compression). Specifically, the bending compressive stress σ _r can be expressed by the product (E × ε) of the constant E (Young's modulus) determined for each material and the strain amount ε. This indicates that the larger the amount of compression in the release layer 24, the larger _{the bending compressive stress σ r acting on the release layer 24.}

As shown in FIG. 4B, when the adhesive layer 22 is thick, when the sheet 2 is bent, bending compressive stresses σ _r -3 and σ _r -4 that try to compress the release layer 24 act. In the following description, when σ _r -1, σ _r -2, σ _r -3, and σ _r -4 are not particularly distinguished, it is simply referred to as “bending compressive stress σ _r ”.

_{The bending compressive stresses σ r} -3 and σ _r -4 applied to the peeling layer 24 in FIG. 4 (b) are compared _{with the bending compressive stresses σ r} -1, σ _r -2 applied to the peeling layer 24 in FIG. 4 (a). And big. This is because the amount by which the release layer 24 is compressed and the length is changed (strain amount ε) is larger than that when the adhesive layer 22 is thin. For example, when the upper surface of the sheet 2 having a length L and a thickness T is bent with a radius of curvature r, the bottom surface of the sheet 2 is bent with a radius of curvature (r−T). The strain amount ε generated on the bottom surface of the sheet 2 in this case can be indicated by L × T / r. That is, it can be seen that the strain amount ε is proportional to the thickness T. Therefore, since the bending compressive stress σ _r is proportional to the product (E × ε) of Young's modulus E and the strain amount ε, the bending compressive stress σ _r is proportional to the thickness T. Therefore, the thicker the adhesive layer 22, the larger _{the bending compressive stress σ r acting on the peeling layer 24.} Further, the strain amount ε is inversely proportional to the radius of curvature r, and the smaller the radius of curvature r of the peeling layer 24 or the larger the distance y ′, the larger the bending compressive stress σ _r acting on the peeling layer 24.

Then, the calculation of the bending compressive stress σ _r will be described. The bending compressive stress calculation means 12 calculates the bending compressive stress σ _r using the equation (7). As described above, the bending compressive stress σ _r is proportional to the thickness and proportional to the distance y ′. Further, the radius r of the winding core 1 can be said to be the radius of curvature of the bottom surface of the release layer 24. In this case, the radius of curvature at neutral axis position m is _{r + t in / 2 + y'} . As described above, the bending compressive stress σ _r is inversely proportional to the radius of curvature of the upper surface of the bent sheet 2 (here, the surface passing through the neutral axis position m and parallel to the sheet surface). Thus, the bending compressive stress sigma _r is inversely proportional to the radius of curvature _{r + t in / 2 + y'} . Then, half the thickness _{t in} the peeling layer 24 _(t in / 2) is smaller enough to be negligible compared with the radius r of the winding core 1, r _{+ t in} / 2 is, be approximated is regarded as equivalent to r Can be done. Further, when the distance y'is negligibly small as compared with the radius r of the winding core 1, r + y'can be regarded as equivalent to r and approximated. In the above equation (5), the bending compressive stress σ _r is inversely proportional to the radius of curvature r of the winding core 1, but the present invention is not limited to this. To r of equation _(5), may be used _{r + t in / 2 + y'} , may be used r _{+ t in} / 2, may be used r + y '.

Returning to Figure 1, wrinkling stress calculating means 14, wrinkles wavelength wrinkle wavelength calculating unit 11 is calculated lambda, the Young's modulus E _in the peeling layer _24, on the basis of the thickness t _in, the peeling layer 24, bending the sheet 2 _{The wrinkle-generating stress σ cr} that causes wrinkles in the peeling layer 24 is calculated. The wrinkle-generating stress σ _cr is a force that causes wrinkles on the peeling layer 24 when a force for compressing the peeling layer 24 (bending compressive stress σ _{r) is applied by bending the sheet 2.} That is, when the bending compressive stress σ _r exceeds the wrinkle generation stress σ _cr , wrinkles are generated on the sheet 2. Therefore, when the sheet 2 is wound around the winding core 1, wrinkles do not occur on the sheet 2 _{if the bending compressive stress σ r} does not exceed the wrinkle generation stress σ _cr. The wrinkle generation stress calculation means 14 _{can output the calculated wrinkle generation stress σ cr} to the wrinkle generation degree calculation means 16.

As described above, when the sheet 2 is bent, wrinkles do not occur in the release layer 24 unless _{the bending compressive stress σ r} exceeds the wrinkle generation stress σ _cr. The wrinkle generation stress σ _cr is expressed by the following equation (8). Here, EI is (4) the bending stiffness, lambda wrinkle wavelength shown in (1), t _in the peeling layer 24 in the expression indicating the thickness of the release layer 24, k is a critical value, respectively.

As shown in the above equation (8), the wrinkle generation stress σ _cr is proportional to the flexural rigidity EI of the peeling layer 24. That is, the higher the flexural rigidity EI (difficult to bend), the larger the _{force required to generate wrinkles (wrinkle generation stress σ cr).} Further, the wrinkle generation stress σ _cr is inversely proportional to the square of the wrinkle wavelength λ, and the smaller the wrinkle wavelength λ _{, the larger the wrinkle generation stress σ cr} as a square function. Also, wrinkles generated stress _{sigma cr} is inversely proportional to the thickness _{t in} the peeling layer 24, as the thickness _{t in} the peeling layer 24 is large (thick), wrinkling stress _{sigma cr} decreases.

Here, the critical value k will be described. The critical value k is a proportional constant indicating the degree of influence _{of the peeling layer 24 on the wrinkle generation stress σ cr} due to being laminated together with the adhesive layer 22 and the peeling layer 20. When the release layer 24 is not a part of the sheet 2 and is compressed by itself, the release layer 24 is not laminated with the adhesive layer 22 and the release layer 20. In this case, the critical value k is 4π ² ≈ 36. That is, in the above equation (8), when the critical value k is 4π ² _{, the wrinkle generation stress σ cr} when the peeling layer 24 is compressed by itself is shown.
In the present embodiment, the release layer 24 is in contact with the adhesive layer 22. Therefore, when the release layer 24 is compressed, the release layer 24 is in contact with the adhesive layer 22 and is affected by the adhesive layer 22, and the wrinkle generation stress σ is different from that when the release layer 24 is a single body. _It is considered to be cr. _{That is, it is considered that the wrinkle generation stress σ cr} is different between the single peeling layer 24 and the peeling layer 24 laminated on the adhesive layer 22 and the peeling layer 20.
That is, in the above equation (8), the wrinkle generation stress σ _{cr of the} peeling layer 24 laminated together with the adhesive layer 22 and the peeling layer 20 is k / (4π ² ) times that of the single peeling layer 24. Is shown.

The critical value k is a constant value regardless of the material and thickness of the release layers 20 and 24 forming the sheet 2 and the adhesive layer 22.

Returning to FIG. 1, the wrinkle occurrence degree calculation means 16 has wrinkle occurrence degree based on the bending compressive stress σ _{r calculated by the bending compressive stress calculation means 12 and the wrinkle generation stress σ cr} calculated by the wrinkle generation stress calculation means 14. Calculate A. The wrinkle occurrence degree A indicates the degree of wrinkle occurrence in the release layer 24 due to the bending of the sheet 2. The wrinkle occurrence degree A is expressed by the following equation (9). Here, lambda wrinkle wavelength shown in (4), y 'denotes each distance, r of the winding core 1 radius, t _in the thickness of the release layer 24 shown in (6).

In the above equation (9), the wrinkle occurrence degree A indicates that the larger the value of the wrinkle occurrence degree A is, the more wrinkles are likely to occur in the peeling layer 24 as compared with the case where the wrinkle occurrence degree A is small. The degree of wrinkle occurrence A is proportional to the square of the wrinkle wavelength λ. That is, as the wrinkle wavelength λ of the wrinkles generated in the peeling layer 24 increases, the wrinkle occurrence degree A increases in a square function. Since the wrinkle occurrence degree A is proportional to the distance y', the larger the intermediate position between the release layer 24 and the neutral axis position m (for example, the thicker the adhesive layer 22), the larger the wrinkle occurrence degree A. Since the wrinkle occurrence degree A is inversely proportional to the radius r of the winding core 1, it increases as the radius of the winding core 1 becomes smaller. Wrinkling degree A is inversely proportional to the square of the thickness t _in the peeling layer 24, increases the square functionally as the thickness of the release layer 24 becomes thinner.

The wrinkle occurrence degree calculation means 16 calculates the wrinkle occurrence degree A based on _{the bending compressive stress σ r} and the wrinkle generation stress σ _cr. As described above, the bending compressive stress σ _r is a force acting on the release layer 24 when the sheet 2 is bent. Further, the wrinkle generation stress σ _cr is a force required to cause wrinkles in the peeling layer 24. From this, it is considered that when the bending compressive stress σ _r exceeds the wrinkle generation stress σ _cr , wrinkles are generated in the peeling layer 24. Specifically, the wrinkle occurrence degree calculation means 16 calculates the wrinkle occurrence degree A based on the wrinkle occurrence condition shown in the following equation (10). Here, σ _r indicates the bending compressive stress shown in Eq. (7), and σ _cr indicates the wrinkle-generating stress shown in Eq. (8).

σ _r > σ _cr ... (10)

_{Substituting the bending compressive stress σ r} shown in the equation (7) _{and the wrinkle generation stress σ cr} shown in the equation (8) into the above equation (10), the variables (wrinkle wavelength λ, distance y ′, radius r, thickness) are substituted. and t _in), and solving to organize the constant (critical value k or the like), and shown below (11).

The term on the left side of the above equation (11) is defined as the wrinkle occurrence degree A.

Here, the flow of processing performed by the calculation system 10 will be described with reference to FIG. FIG. 6 is a flowchart showing a flow of processing for calculating the wrinkle occurrence degree A performed by the calculation system 10.
First, as a premise, parameters used when calculating the wrinkle occurrence degree A (thickness, Young's modulus, Young's modulus, critical value of each of the three layers forming the sheet 2) are input to the calculation system 10.

Wrinkle wavelength calculating unit 11 on the basis of the thickness _{t in} the peeling layer 24 and the Young's modulus _{E in} the peeling layer 24, to calculate the flexural rigidity EI of the release layer 24 shown in (1) (step S1). Further, the wrinkle wavelength calculating means 11 calculates the thickness ratio ν represented by the equation (2) based on the thickness to _{out of the peeling layer 20 and the thickness to mid of the adhesive layer 22 (step S2).} Then, the wrinkle wavelength calculating means 11 calculates the rigidity parameter G shown in the equation (3) using the calculated bending rigidity EI and the thickness ratio ν of the peeling layer 24 (step S3). The wrinkle wavelength calculation means 11 calculates the wrinkle wavelength λ represented by the equation (4) from the calculated rigidity parameter G (step S4).

The bending compressive stress calculating means 12 calculates the neutral axis position m represented by the equation (5) based on the Young's modulus and the thickness of each of the peeling layers 20 and 24 and the adhesive layer 22 (step S5). Then, the bending compressive stress calculating means 12 calculates the distance y'expressed in Eq. (6) based on the calculated neutral axis position m and the thicknesses of the peeling layers 20, 24, and the adhesive layer 22 (step S6). ). The bending compressive stress calculating means 12 uses the Young's modulus E _in of the peeling layer 24, the calculated distance y', and the radius r of the winding core 1 to calculate the bending compressive stress σ _r of the peeling layer 24 shown in Eq. (7). Calculate (step S7).

Creasing stress calculating means 14, (1) the flexural rigidity EI of the release layer 24 shown in the expression (4) wrinkles wavelength λ wrinkles wavelength calculating unit 11 is calculated in the expression, the thickness of the release layer 24 t _in, and the critical Based on the value k, the wrinkle generation stress σ _cr shown in Eq. (8) is calculated (step S8).

The wrinkle generation degree calculation means 16 is based on the bending compressive stress σr calculated by the bending compressive stress calculation means 12, the wrinkle generation stress σcr calculated by the wrinkle generation stress calculation means 14, and the wrinkle generation conditions shown in the equation (10). 9) The wrinkle occurrence degree A shown in the equation is calculated (step S9). Then, the process shown in this flowchart is terminated.
In the above-mentioned flowchart, the calculation system 10 performs the calculation of the wrinkle wavelength λ by the wrinkle wavelength calculation means 11 and the bending compression stress σ _r by the bending compression stress calculation means 12, respectively. It may be calculated in. For example, the wrinkle wavelength λ may be calculated by the wrinkle wavelength calculating means 11 after the process of calculating the _{bending compressive stress σ r} by the bending compressive stress calculating means 12. Further, when calculating the wrinkle wavelength λ, the wrinkle wavelength calculating means 11 calculates the thickness ratio ν and the flexural rigidity EI in this order, but any of them may be calculated first. For example, the wrinkle wavelength calculating means 11 may calculate the thickness ratio ν after calculating the flexural rigidity EI.

As described above, in the calculation system 10 of the present embodiment, the release layer 24 (an example of the “inner layer”), the adhesive layer 22 (an example of the “intermediate layer”), and the release layer 20 (an example of the “outer layer”). When winding the long sheet 2 (an example of "web") formed by the three layers laminated in the order of) around the winding core 1 (when holding it on the body surface of the columnar roller). Example) A calculation system that calculates the degree of wrinkles on the peeling layer 24 inside the bending as the degree of wrinkling, based on the Young's modulus of the peeling layer 24 and the thickness of each of the three layers. With the wrinkle wavelength calculation means 11 (an example of the "first calculation means") for calculating the wrinkle wavelength λ (an example of the "wrinkle wavelength which is the wavelength of the wrinkle") generated in the peeling layer 24 when the winding core 1 is wound around. , The neutral axis position m of the sheet 2, the thickness of the sheet 2, the thickness of the release layer 24, the Young's modulus of the release layer 24, and the curvature r when the sheet 2 is wound around the winding core 1 (that is, the radius r of the winding core 1). ), The bending compressive stress calculating means 12 (an example of the "second calculating means") for calculating _{the bending compressive stress σ r} acting on the peeling layer 24, the wrinkle wavelength λ, the bending rigidity of the peeling layer 24, and the peeling. Wrinkle generation stress calculation means 14 (“third calculation”) for calculating _{wrinkle generation stress σ cr} , which is a compressive stress that causes wrinkles in the release layer 24 when the sheet 2 is wound around the winding core 1 based on the thickness of the layer 24. An example of the "means") and a wrinkle occurrence degree calculation means 16 (an example of the "fourth calculation means") for calculating the wrinkle occurrence degree A based on the bending compressive stress and the wrinkle generation stress σ _cr.

As a result, the calculation system 10 of the embodiment calculates the wavelength λ of the wrinkles generated in the peeling layer 24 when the sheet 2 is bent, thereby generating the force required to generate the wrinkles of the wavelength λ in the peeling layer 24. (Wrinkle generation stress σ _cr ) can be calculated. Further, the calculation system 10 calculates the force (bending compressive stress σ _r) acting on the peeling layer 24 when the sheet 2 is bent, and obtains the relationship between the bending compressive stress σ _r and the wrinkle generation stress σ _cr. The degree of wrinkling in the peeling layer 24 when the sheet 2 is bent (wrinkle occurrence degree A) can be calculated.

Further, in the calculation method of the present embodiment, the release layer 24 (an example of the "inner layer"), the adhesive layer 22 (an example of the "intermediate layer"), and the release layer 20 (an example of the "outer layer") are laminated in this order. When winding a long sheet 2 (an example of a "web") formed by three layers around a winding core 1 (an example of "holding it on the body surface of a columnar roller"), bending This is a calculation method for calculating the degree of wrinkles on the inner peeling layer 24 as the degree of wrinkles.
In the calculation method of the present embodiment, the release layer 24 is formed when the sheet 2 is wound around the winding core 1 based on the Young's modulus of the release layer 24 and the thickness of each of the three layers by the steps shown in steps S1 to S4. It has a first calculation step for calculating the wrinkle wavelength λ (an example of “wrinkle wavelength which is the wavelength of wrinkles”) generated in.
Further, in the calculation method of the present embodiment, the neutral axis position m of the sheet 2, the thickness of the sheet 2, the thickness of the release layer 24, the Young's modulus of the release layer 24, and the sheet 2 are determined by the steps shown in steps S5 to S7. It has a second calculation step of calculating the _{bending compressive stress σ r} acting on the peeling layer 24 based on the curvature r when winding around the winding core 1 (that is, the radius r of the winding core 1).
Further, in the calculation method of the present embodiment, when the sheet 2 is wound around the winding core 1 based on the wrinkle wavelength λ, the flexural rigidity of the peeling layer 24, and the thickness of the peeling layer 24 by the step shown in step S8. It has a third calculation step of calculating the _{wrinkle generation stress σ cr} , which is the compressive stress that causes wrinkles in the peeling layer 24.
Further, the calculation method of the present embodiment includes a fourth calculation step of calculating the wrinkle occurrence degree A based on _{the bending compressive stress and the wrinkle generation stress σ cr by the step shown in step S9.}

Thereby, the calculation method of the embodiment calculates the wavelength λ of the wrinkles generated in the peeling layer 24 when the sheet 2 is bent, thereby generating the force (force) required to generate the wrinkles of the wavelength λ in the peeling layer 24. The wrinkle generation stress σ _cr ) can be calculated. Further, the calculation system 10 calculates the force (bending compressive stress σ _r) acting on the peeling layer 24 when the sheet 2 is bent, and obtains the relationship between the bending compressive stress σ _r and the wrinkle generation stress σ _cr. The degree of wrinkling in the peeling layer 24 when the sheet 2 is bent (wrinkle occurrence degree A) can be calculated.

7 and 8 are diagrams showing Tables 1 and 2 in which the calculation results performed by the calculation system 10 and the results of visually confirming whether or not wrinkles have occurred are associated with each other. In FIGS. 7 and 8, the columns are the numbers of the take-up roll body 3 composed of the sheet 2 and the winding core 1 (hereinafter, simply referred to as “sheet numbers”), and the rows are the parameters related to the take-up roll body 3 corresponding to the numbers. be written. From the left side, the parameters related to the take-up roll body 3 are the parameters used by the calculation system 10 to calculate the wrinkle occurrence degree A (thickness of each of the three layers forming the sheet 2 and Young's modulus), and the wrinkle wavelength calculated by the calculation system 10. λ, the distance y', the diameter 2r of the winding core 1 for winding the sheet 2, the wrinkle occurrence degree A calculated by the calculation system 10, and the "visual result" are shown, respectively. The "visual result" shows that the sheet 2 is wound around the outer circumference of the winding core 1 for one round, the end of the sheet 2 when the sheet 2 is wound around the winding core 1 is fixed to the winding core 1, and one minute has passed. This is the result of visually confirming the presence or absence of wrinkles. In the "visual result", "x" is shown when wrinkles are generated on the entire sheet 2, and "○" is shown when wrinkles are not generated on the sheet 2.
As shown in FIG. 7, the sheet numbers "1" and "2" are a 75 μm-thick polyethylene terephthalate film in which an adhesive layer having a thickness of 250 μm is subjected to a peeling treatment on one side of the outer peeling layer and the inner peeling layer. The same sheet 2 sandwiched between the two is used. In the sheet number "1", when the diameter 2r of the winding core 1 is 50 [mm], the wrinkle occurrence degree A is "9.09", and the visual result shows "x", that is, wrinkles occur in the entire sheet 2. It was confirmed that it was done. On the other hand, in the sheet number "2", when the diameter 2r of the winding core 1 is 100 [mm], the wrinkle occurrence degree A is "4.59", and the visual result is "○", that is, the sheet 2 has wrinkles. It was confirmed that it did not occur. This indicates that wrinkles do not occur when the value is less than "4.5", but wrinkles may occur on the sheet 2 when the value of the degree of wrinkle occurrence A exceeds "9.1". ..

Further, for the sheet numbers "3" and "4", the thickness of the adhesive layer was doubled and the thickness of each of the outer and inner peeling layers was halved as compared with the case of the sheet number "1". The material is used. In the sheet number "3", when the diameter 2r of the winding core 1 was set to 300 [mm], the wrinkle occurrence degree A was "10.02", which was "x" in the visual result. Further, in the sheet number "4", when the diameter 2r of the winding core 1 was 350 [mm], the wrinkle occurrence degree A was "8.52", which was "x" in the visual result. This indicates that wrinkles may occur on the sheet 2 when the value of the wrinkle occurrence degree A exceeds "8.6".

Further, in the sheet numbers "5" and "6", a material in which the thickness of each of the outer and inner release layers is thicker than that of the sheet number "3" is used. In the sheet number "5", when the diameter 2r of the winding core 1 was 325 [mm], the wrinkle occurrence degree A was "6.93", which was "x" in the visual result. Further, in the sheet number "6", when the diameter 2r of the winding core 1 was 350 [mm], the wrinkle occurrence degree A was "6.44", which was "◯" in the visual result. This means that wrinkles do not occur when the value of wrinkle occurrence degree A is less than "6.4", but wrinkles may occur on the sheet 2 when it exceeds the vicinity of "6.9". Shown.

Further, in the sheet numbers "7" and "8", a material having twice the thickness of the adhesive layer is used as compared with the case of the sheet number "1". In the sheet number "7", when the diameter 2r of the winding core 1 was 250 [mm], the wrinkle occurrence degree A was "7.31", which was "x" in the visual result. Further, in the sheet number "8", when the diameter 2r of the winding core 1 was set to 300 [mm], the wrinkle occurrence degree A was "6.09", which was "◯" in the visual result. This is because wrinkles do not occur when the value of wrinkle occurrence degree A is less than "6.0", but wrinkles start to occur on the sheet 2 near "6.65", and around "7.31". It is shown that wrinkles may occur on the sheet 2 when the amount is exceeded.

Further, in the sheet numbers "9" and "10", a material in which the thickness of each of the outer and inner release layers is thicker than that of the sheet number "7" is used. In the sheet number "9", when the diameter 2r of the winding core 1 was set to 200 [mm], the wrinkle occurrence degree A was "6.71", which was "x" in the visual result. Further, in the sheet number "10", when the diameter 2r of the winding core 1 was set to 225 [mm], the wrinkle occurrence degree A was "5.97", which was "◯" in the visual result. This indicates that wrinkles do not occur when the value of the wrinkle occurrence degree A is less than "5.9", but wrinkles may occur on the sheet 2 when the value exceeds "6.7". .. This result is consistent with the previous results described above.

Further, in the sheet numbers "11" and "12", a material in which the thickness of each of the outer and inner peeling layers is thicker than that of the sheet number "9" is used. In the sheet number "11", when the diameter 2r of the winding core 1 was 150 [mm], the wrinkle occurrence degree A was "7.16", which was "x" in the visual result. Further, in the sheet number "12", when the diameter 2r of the winding core 1 was set to 175 [mm], the wrinkle occurrence degree A was "6.13", which was "◯" in the visual result. This result is consistent with the previous results described above.

Further, in FIG. 8, in the sheet numbers "13" and "14", a material having a thickness of the inner peeling layer thinner than that of the sheet number "11" is used. In the sheet number "13", when the diameter 2r of the winding core 1 was 150 [mm], the wrinkle occurrence degree A was "7.62", which was "x" in the visual result. Further, in the sheet number "14", when the diameter 2r of the winding core 1 was set to 200 [mm], the wrinkle occurrence degree A was "5.72", which was "◯" in the visual result. This result shows that even when the thickness of the outer and inner release layers is different, it is consistent with the above-mentioned previous results.

Further, in the sheet numbers "15" and "16", a material in which the thickness of the inner peeling layer is made thinner than that of the sheet number "13" is used. In the sheet number "15", when the diameter 2r of the winding core 1 was set to 200 [mm], the wrinkle occurrence degree A was "7.48", which was "x" in the visual result. Further, in the sheet number "16", when the diameter 2r of the winding core 1 was 250 [mm], the wrinkle occurrence degree A was "5.99", which was "◯" in the visual result. This result is consistent with the previous results described above.

Further, in the sheet numbers "17" and "18", a material in which the thickness of the adhesive layer is double the thickness of the sheet number "11" is used. In the sheet number "17", when the diameter 2r of the winding core 1 was set to 300 [mm], the wrinkle occurrence degree A was "13.07", which was "x" in the visual result. Further, in the sheet number "18", when the diameter 2r of the winding core 1 was 350 [mm], the wrinkle occurrence degree A was "11.20", which was "x" in the visual result. This result is consistent with the results described above.

Further, in the sheet numbers "19" and "20", a polyethylene film having a thicker inner release layer and a smaller Young's modulus (soft) than in the case of the sheet number "7" is used. In the sheet number "19", when the diameter 2r of the winding core 1 was 60 [mm], the wrinkle occurrence degree A was "8.33", which was "x" in the visual result. Further, in the sheet number "20", when the diameter 2r of the winding core 1 was set to 100 [mm], the wrinkle occurrence degree A was "5.00", which was "◯" in the visual result. This result is consistent with the results described above.

Further, in the sheet numbers "21" and "22", the material in which the inner peeling layer and the outer peeling layer are replaced with those in the case of the sheet number "19" is used. In the sheet number "21", when the diameter 2r of the winding core 1 was set to 50 [mm], the wrinkle occurrence degree A was "8.23", which was "x" in the visual result. Further, in the sheet number "22", when the diameter 2r of the winding core 1 was 75 [mm], the wrinkle occurrence degree A was "5.48", which was "◯" in the visual result. This result is consistent with the results described above.

As described above, as described in FIGS. 7 and 8, even when the thickness and Young's modulus of the material forming the sheet 2 are changed, when the wrinkle occurrence degree A calculated by the calculation system 10 of the embodiment is large. Wrinkles are generated on the sheet 2, and when it is small, wrinkles tend not to occur. Therefore, in the calculation system 10 of the embodiment, it is possible to estimate whether or not wrinkles actually occur from the value of the wrinkle occurrence degree A without actually bending the sheet 2 and confirming the occurrence of wrinkles.

(Winling roll body)
Here, the take-up roll body 3 will be described.
The take-up roll body 3 includes a take-up core 1 and a sheet 2 taken up by the take-up core 1 into a roll shape.
Here, the radius of the winding core 1, the thickness of each of the three layers forming the sheet 2, and the Young's modulus of each of the three layers forming the sheet 2 are determined by the wrinkle occurrence degree A calculated by the calculation system 10 as a predetermined criterion. It is a relationship that satisfies. The predetermined determination criterion is a value corresponding to the degree of wrinkle occurrence A in which wrinkles do not occur when the sheet 2 is wound around the winding core 1. For example, based on the results of FIG. 7, the Young's modulus of the release layers 20 and 24 is 4.00E + 09 [Pa], the thickness of the release layers 20 and 24 is in the range of 50 to 125 [μm], and further. The Young's modulus of the adhesive layer 22 is 1.10E + 05 [Pa], the thickness of the adhesive layer 22 is in the range of 250 to 500 [μm], and the radius of the winding core 1 is in the range of 50 to 350 [mm]. In this case, if the wrinkle occurrence degree A is lower than the reference value B (about 6.50), wrinkles do not occur when the sheet 2 is wound around the winding core 1.

In the take-up roll body 3, the radius r of the winding core 1, the thickness of each of the three layers forming the sheet 2, and the Young's modulus of each of the three layers forming the sheet 2 may be determined in any way. For example, when the three-layer material forming the sheet 2 and the thickness of the adhesive layer 22 are determined, the wrinkle occurrence degree A is less than the reference value B = 6.50, so that the thicknesses and windings of the release layers 20 and 24 are formed. The radius r of the core 1 can be selected from the viewpoint of manufacturing the sheet 2 and manufacturing cost. Specifically, based on the results of FIG. 7, it is necessary to increase the radius of the winding core 1 when the thickness of each of the release layers 20 and 24 is thin, and conversely when the thickness of the release layer is thick. The radius of the winding core 1 can be reduced. More specifically, the relationship of (thickness of each of the release layers 20 and 24, diameter of the winding core 1 2r) is (50 [μm], 350 [mm]), (75 [μm], 300 [mm]. ), (100 [μm], 225 [mm]), (125 [μm], 175 [mm]). For example, if the winding core 1 having a large radius cannot be used due to the manufacturing space of the sheet 2, the thicknesses of the release layers 20 and 24 of the sheet 2 are increased. If the manufacturing cost is high when the release layer is thickened, the thickness of the release layer is reduced and the radius of the winding core 1 is increased. In this way, by selecting the thickness of each of the three layers forming the sheet 2 and the radius of the winding core 1 so that the wrinkle occurrence degree A is lower than the reference value B, the winding roll body 3 of the present embodiment is selected. In, the occurrence of wrinkles on the sheet 2 can be suppressed.

The reference value B is not limited to the above-mentioned value (6.50), and may be a value smaller than 6.50. If the reference value B is smaller than 6.50, the take-up roll body 3 can more reliably suppress the occurrence of wrinkles on the sheet 2.
Based on FIGS. 7 and 8, the reference value B is 6.50 or 6.50 in consideration of a predetermined margin, but is not limited thereto.

Further, since the reference value B is a uniform value regardless of the combination of materials and the like, it is possible to predict the degree of wrinkle occurrence to some extent in advance before actually bending the sheet.

As described above, the winding roll body 3 of the present embodiment includes a winding core 1 and a sheet 2 (an example of a “web”) wound around the winding core 1, and has a winding core radius r and a sheet. Regarding the thickness of each of the three layers forming 2 and the Young's modulus of each of the three layers forming the sheet 2, the wrinkle occurrence degree A calculated by the calculation system 10 is based on the reference value B (an example of a "predetermined determination standard"). It is a satisfying relationship. As a result, in the winding roll body 3 of the present embodiment, when the sheet 2 is wound by the winding core 1, wrinkles can be prevented from occurring on the sheet 2.

The calculation system 10 in the above-described embodiment may be realized by a computer. In that case, the program for realizing this function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by the computer system and executed. The term "computer system" as used herein includes hardware such as an OS and peripheral devices. Further, the "computer-readable recording medium" refers to a portable medium such as a flexible disk, a magneto-optical disk, a ROM, or a CD-ROM, or a storage device such as a hard disk built in a computer system. Further, a "computer-readable recording medium" is a communication line for transmitting a program via a network such as the Internet or a communication line such as a telephone line, and dynamically holds the program for a short period of time. It may also include a program that holds a program for a certain period of time, such as a volatile memory inside a computer system that serves as a server or a client in that case. Further, the above program may be for realizing a part of the above-mentioned functions, and may be further realized for realizing the above-mentioned functions in combination with a program already recorded in the computer system. It may be realized by using a programmable logic device such as FPGA (Field Programmable Gate Array).

Although the embodiments of the present invention have been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs and the like within a range that does not deviate from the gist of the present invention.

The execution order of each process such as operation, procedure, step, and step in the device, system, program, and method shown in the claims, the specification, and the drawing is particularly "before" and "prior to". It should be noted that it can be realized in any order unless the output of the previous process is used in the subsequent process. Even if the scope of claims, the specification, and the operation flow in the drawings are explained using "first", "next", etc. for convenience, it means that it is essential to carry out in this order. It's not a thing.

1 ... Winding core, 2 ... Sheet, 20 ... Peeling layer, 22 ... Adhesive layer, 24 ... Peeling layer, 3 ... Winding roll body, 10 ... Calculation system, 11 ... Wrinkle wavelength calculation means, 12 ... Bending compressive stress calculation means , 14 ... Wrinkle generation stress calculation means, 16 ... Wrinkle occurrence degree calculation means.

Claims (4)

When a long web formed by three layers, which are laminated in the order of an inner layer, an intermediate layer, and an outer layer, is held on the body surface of a columnar roller, wrinkles occur in the inner layer, which is the inner layer of bending. It is a calculation system that calculates the degree of wrinkles as the degree of wrinkles.
Based on the Young's modulus of the inner layer and the thickness of each of the three layers, the wrinkle wavelength, which is the wavelength of the wrinkles generated in the inner layer when the web is held on the body surface of the columnar roller, is calculated. First calculation means and
The inner layer is based on the neutral axis position of the web, the thickness of the web, the thickness of the inner layer, the Young's modulus of the inner layer, and the curvature when the web is held on the body surface of the columnar roller. A second calculation means for calculating the bending compressive stress acting on the
A wrinkle that is a compressive stress that causes wrinkles in the inner layer when the web is held on the body surface of the columnar roller based on the wrinkle wavelength, the flexural rigidity of the inner layer, and the thickness of the inner layer. The third calculation means for calculating the generated stress and
A fourth calculation means for calculating the degree of wrinkle generation based on the bending compressive stress and the wrinkle generation stress, and
Calculation system with. The first calculation means is a means for calculating the wrinkle wavelength λ shown in the formula (4) by using the following formulas (1) to (4).

The second calculation means is a means for calculating the _{bending compressive stress σ r} shown in the formula (7) by using the following formulas (5) to (7).

The third calculation means is a means for calculating the _{wrinkle generation stress σ cr} shown in the following equation (8).

The fourth calculation means is a means for calculating the wrinkle occurrence degree A shown in the following equation (9).

The calculation system according to claim 1. When a long web formed by three layers, which are laminated in the order of an inner layer, an intermediate layer, and an outer layer, is held on the body surface of a columnar roller, wrinkles occur in the inner layer which is the inner side of bending. It is a calculation method that calculates the degree of wrinkles as the degree of wrinkles.
Based on the Young's modulus of the inner layer and the thickness of each of the three layers, the wrinkle wavelength, which is the wavelength of the wrinkles generated in the inner layer when the web is held on the body surface of the columnar roller, is calculated. The first calculation process and
The inner layer is based on the neutral axis position of the web, the thickness of the web, the thickness of the inner layer, the Young's modulus of the inner layer, and the curvature when the web is held on the body surface of the columnar roller. The second calculation process for calculating the bending compressive stress acting on
A wrinkle that is a compressive stress that causes wrinkles in the inner layer when the web is held on the body surface of the columnar roller based on the wrinkle wavelength, the flexural rigidity of the inner layer, and the thickness of the inner layer. The third calculation process for calculating the generated stress and
A fourth calculation step of calculating the degree of wrinkle generation based on the bending compressive stress and the wrinkle generation stress, and
Calculation method including. The winding core so that the wrinkle occurrence degree calculated by the calculation system according to claim 1 or 2 satisfies a predetermined criterion determined to wind the web so that the web does not wrinkle. A design process for designing each of the radius, the thickness of each of the three layers forming the web, and the Young's modulus of each of the three layers forming the web.
A winding method comprising a winding step of winding the web on a winding core having a radius adjusted by the design process to generate a winding roll body.

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