Processing equipment for punching

Abstract

To provide a processing device for punching that reduces the frequency of replacing a resin sheet used as an underlay for a workpiece. [Solution] The processing device 1 for punching comprises a punching die 3 having a punching blade 32, a self-repairing sheet 5 on which the workpiece 2 is placed, and a receiving die 4 for supporting the self-repairing sheet 5 and receiving the punching die 3, and the self-repairing sheet 5 has a sheet-like resin substrate 50 and a self-repairing layer 51 provided on the surface of the resin substrate 50 facing the punching die 3, and the breaking elongation of the self-repairing layer 51 in both the MD and TD directions is 15% or more.

Description

[Technical Field]

[0001] The present invention relates to a processing device for punching. [Background technology]

[0002] Patent Document 1 discloses a film trimming die attached to a press machine for punching out a synthetic resin product (workpiece) into a predetermined punching shape (paragraph 0023 of the specification and figures 1 and 2). The film trimming die is composed of a punching die (punching part), which is an upper die attached to the upper platen of the press machine, and a receiving die (receiving part), which is a lower die attached to the lower platen of the press machine. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-27591 Summary of the Invention [Problem to be solved by the invention]

[0004] One issue with this type of technology is that when the workpiece is difficult to punch, the cross section of the punched workpiece becomes rough, which causes problems with aesthetics and processing efficiency.By placing a resin sheet on the receiving part as an underlay for the workpiece, the cross section of the punched workpiece becomes beautiful and processing efficiency is improved.

[0005] However, the resin sheet needs to be replaced because it is damaged by the punching blade, but if it is replaced frequently, it takes time and effort, and processing becomes inefficient. The object of this invention is to reduce the replacement frequency of the resin sheet used as an underlay for the workpiece. [Means for solving the problem]

[0006] The present disclosure relates to a processing device for punching, which includes a punching unit with a punching blade, a self-repairing sheet on which the workpiece is placed, and a receiving unit for supporting the self-repairing sheet and receiving the punching unit, the self-repairing sheet having a sheet-like resin substrate and a self-repairing layer provided on the surface of the resin substrate facing the punching unit, and the self-repairing layer having a breaking elongation of 15% or more in both the MD and TD directions. [Effects of the Invention]

[0007] In the processing apparatus according to the present disclosure, a self-repairing sheet having a self-repairing layer is used as an underlay for the workpiece, and since the breaking elongation of the self-repairing layer in both the MD and TD directions is 15% or more, the frequency of replacement of the self-repairing sheet can be reduced. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a processing device according to a first embodiment. [Figure 2] FIG. 2 is a cross-sectional view showing the self-repairing sheet. [Figure 3] FIG. 3 is a schematic view showing a processing device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments of the present disclosure are described below.

[0010] (First embodiment) The processing device 1 according to the first embodiment is used to punch out the workpiece 2, and is, for example, a press machine equipped with an upper surface plate and a lower surface plate. The workpiece 2 may be made of, for example, resin or paper, and may be in a sheet form. When the workpiece 2 is in a sheet form, there is no particular limitation on the thickness. The workpiece 2 may be in a rectangular sheet form. The workpiece 2 may also be in a long sheet form wound on a roll.

[0011] As shown in FIG. 1, the processing device 1 includes a punching die 3 (punching section), a receiving die 4 (receiving section) disposed below the punching die 3 for receiving the punching die 3, and a self-repairing sheet 5 disposed on the receiving die 4. The punching die 3 includes a punch holder 30, a punch plate 31 disposed below the punch holder 30, and a punching blade 32 protruding downward from the punch plate 31. The punch holder 30 is fixed to an upper surface plate. Examples of the punching blade 32 include an engraving blade type, a Thomson type, and an erosion blade type. The shape of the punching blade 32 is not particularly limited. The punching blade 32 may have any shape that matches the shape to be punched.

[0012] The receiving die 4 has a receiving plate 40 on the upper side of which the self-repairing sheet 5 is placed, a die plate 41 that supports the receiving plate 40 from the lower side, and a die holder 42 that supports the die plate 41 from the lower side. The die holder 42 is fixed to the lower surface plate. The distance (gap amount) between the upper surface of the receiving plate 40 and the tip of the punching blade 32 when the punching die 3 is lowered may be set to an appropriate value depending on the type of workpiece 2 and punching blade 32, the hardness of the self-repairing sheet 5, etc.

[0013] 2, the self-repairing sheet 5 has a sheet-like resin base material 50 and a self-repairing layer 51 provided on the upper surface (the surface facing the punching die 3) of the resin base material 50. The self-repairing sheet 5 is, for example, a rectangular sheet.

[0014] The resin substrate 50 is preferably made of a material selected from the group consisting of polyester resins such as polyethylene terephthalate (PET), polystyrene (PS), polyethylene (PE), and polypropylene. The resin substrate 50 may be a single-layer resin sheet made of these resins or other materials. The resin substrate 50 may also be a laminated resin sheet having multiple layers made of these resins or other materials.

[0015] The self-repairing layer 51 has the function of naturally recovering to its original state due to, for example, elasticity, intermolecular interactions, etc. Therefore, even if the self-repairing layer 51 is scratched, the scratch will naturally repair itself over time. The self-repairing layer 51 is a layer composed of, for example, a so-called self-healing material or a self-restoring material. The self-repairing layer 51 is preferably formed of a urethane resin, a cured product of a UV-curable resin, or a cured product of a solventless resin. The self-repairing layer 51 can be formed, for example, by drying or curing a paint containing the above-mentioned resin. The paint may contain a solvent or may be solventless. Solventless paint is preferable because it is environmentally friendly since the organic solvent does not volatilize. UV-curable paint is preferable because it is less likely to foam during film formation and the self-repairing layer 51 can be formed relatively easily.

[0016] The self-repairing layer 51 has a breaking elongation of 15% or more in both the MD and TD directions. Therefore, the self-repairing layer 51 has the property of stretching when subjected to stress from the punching blade 32. As a result, the self-repairing layer 51 is less likely to be damaged or scratched even when the punching blade 32 bites into it. The self-repairing layer 51 may or may not be stretched during film formation.

[0017] From the viewpoint of making it easier to punch out the workpiece 2, the self-repairing layer 51 preferably has a breaking elongation in the MD and TD directions of 200% or less, more preferably 100% or less, and even more preferably 50% or less.

[0018] The breaking elongation in the MD direction of the self-repairing layer 51 is preferably smaller than the breaking elongation in the MD direction of the resin base material 50. The breaking elongation in the TD direction of the self-repairing layer 51 is preferably smaller than the breaking elongation in the TD direction of the resin base material 50. The thickness of the self-repairing layer 51 is preferably 10 μm or more and 500 μm or less.

[0019] The breaking strength in the MD direction of the self-repairing sheet 5 is not limited, but is, for example, 50 MPa or more, and preferably 70 MPa or more. The breaking strength in the TD direction of the self-repairing sheet 5 is, for example, 70 MPa or more, and preferably 90 MPa or more. If at least one of the resin substrate 50 and the self-repairing layer 51 is formed from a stretched film and is therefore less stretchable in the TD direction than in the MD direction, for example, the breaking strength of the self-repairing sheet 5 may be greater in the TD direction than in the MD direction.

[0020] The breaking elongation and breaking strength can be measured by a method in accordance with JIS K 7127: 1999. More specifically, they can be measured by the method used in the examples described below.

[0021] The self-repairing sheet 5 may be transparent or colored. When the self-repairing sheet 5 is colored, it is easier to visually recognize that the self-repairing sheet 5 has peeled off and adhered to the workpiece 2.

[0022] The thickness of the self-repairing layer 51 is not particularly limited, but from the viewpoint of making it difficult to be completely cut during punching, it is preferably 10 μm or more, more preferably 20 μm or more, and even more preferably 50 μm or more. The thickness of the self-repairing layer 51 is preferably 500 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less, from the viewpoint of concentrating the stress applied by the punching blade 32 at the cut point in order to make the cut surface of the workpiece 2 as beautiful as possible.

[0023] -Processing method- In the processing device 1 according to this embodiment, the workpiece 2 is placed on top of the self-repairing sheet 5, and the punching die 3 is lowered from above, and the workpiece 2 is cut by the punching blade 32. At this time, by lowering the punching die 3 to a position where the punching blade 32 bites into the self-repairing layer 51, it becomes easier to completely cut the workpiece 2. When cutting, the workpiece 2 may be placed stationary on top of the self-repairing sheet 5, or may be transported at a constant speed by a belt or the like. If the workpiece 2 is wound on a roll, it may be unwound from the roll and cut while being transported.

[0024] When punching, the workpiece 2 is punched continuously at regular time intervals. During this process, the self-repairing layer 51 is damaged when the punching blade 32 bites into it, but the damaged portion is repaired by the self-repair function. As such, the processing device 1 according to this embodiment uses the self-repairing sheet 5 having the self-repairing layer 51 as an underlay for the workpiece 2, so that punching can be repeated for a longer period of time, significantly improving productivity.

[0025] In particular, because the breaking elongation of the self-repairing layer 51 in both the MD and TD directions is 15% or more, it is possible to reduce the frequency of replacing the self-repairing sheet 5 when repeatedly punching the workpiece 2. As a result, the workpiece 2 can be processed more efficiently than when the resin base material 50 alone is used as an underlay for the workpiece 2, and productivity can be significantly improved.

[0026] (Second embodiment) A rotary die-cut type processing device 100 will be described below as a second embodiment of the present disclosure. The following mainly describes only the configuration that differs from the first embodiment.

[0027] As shown in FIG. 3, the processing device 100 includes a first roller 102 (punching unit) having a punching blade 101 on its circumferential surface, and a pair of second rollers 103a, 103b (receiving units) that support the self-repairing sheet 5 on their circumferential surfaces. The self-repairing sheet 5 is formed in a ring shape that surrounds the circumferential surfaces of the pair of second rollers 103a, 103b. One second roller 103a is provided with its circumferential surface close to the circumferential surface of the first roller 102 so that the punching blade 101 bites into the self-repairing layer 51 on the circumferential surface. In this way, the one second roller 103a is configured to receive the punching blade 101. The circumferential surface of the first roller 102 is made of a hard material, such as metal.

[0028] The workpiece 2 is in the form of a long sheet, and is wound up to form a roll 2a. The processing device 100 is equipped with conveying rollers 104a, 104b, and 104c for conveying the workpiece 2. The workpiece 2 is driven to rotate by the first roller 102, the second rollers 103a and 103b, the conveying rollers 104a, 104b, and 104c, etc., and is unwound from the roll 2a and conveyed. The workpiece 2 is sandwiched between the first roller 102 and the second roller 103a and is punched by the punching blade 101.

[0029] 3, the two arrows shown near the workpiece 2 indicate the direction in which the workpiece 2 is transported. In FIG. 3, the first roller 102 rotates counterclockwise, and the second rollers 103a and 103b rotate clockwise.

[0030] (Other embodiments) In the first embodiment, a press machine is given as an example of a processing device according to the present disclosure, but the present disclosure is not limited to this. The processing device may include a receiving part, a punching part, and a self-repairing sheet.

[0031] The self-repairing sheet 5 and the workpiece 2 may both be formed in a long shape and wound up to form a roll. In this case, the self-repairing sheet 5 and the workpiece 2 may be punched while being simultaneously unwound from the roll. [Example]

[0032] - Creation of self-repairing sheets - In Example 1, a paint was applied to the adhesive surface of a resin substrate composed of a commercially available 125 μm-thick biaxially oriented PET film (Cosmoshine (registered trademark) A4360 manufactured by Toyobo Co., Ltd.), dried, and then irradiated with UV light to form a 50 μm-thick self-repairing layer, thereby producing a self-repairing sheet. Hereinafter, the paint used in Example 1 will be referred to as "Paint A." Paint A is a commercially available one-component UV-curable urethane-based self-repairing paint (a type that does not require the addition of additional additives, etc.), contains MEK (methyl ethyl ketone) as a solvent, and has a resin solids content of 40%.

[0033] In Examples 2 to 6, self-repairing sheets were produced in the same manner as in Example 1, except that the type of paint was changed and the thickness of the self-repairing layer was 100 μm. Hereinafter, the paints used in Examples 2 to 6 will be referred to as "paints B to F," respectively. Paints B to F were commercially available one-component UV-curable urethane-based self-repairing paints (types that do not require the addition of additional additives, etc.). Paints B to F were solvent-free. Paints E and F each contained the same urethane-based resin as the main component, but had different additives.

[0034] -Measurement of breaking elongation and breaking strength- The breaking elongation and breaking strength of the self-repairing layer in the self-repairing sheets produced in Examples 1 to 6 were measured according to a method in accordance with JIS K 7127:1999. Specifically, strip-shaped test pieces measuring 2 mm wide and 30 mm long were cut from each of the self-repairing sheets produced in Examples 1 to 6, and tensile tests were performed on these test pieces using a universal testing machine (TENSILON (registered trademark) RTI-1225, manufactured by A&D Co., Ltd.) under conditions of a temperature of 23°C, a relative humidity of 50%, a grip spacing of 10 mm, and a pulling speed of 300 mm / min. This tensile test was performed in both the MD and TD directions of the test pieces.

[0035] When a crack occurs in the self-repairing layer due to the tensile test, the length of the test piece at the time when the crack occurs (L1) and the length of the test piece before the tensile test (L0) are calculated. 100×(L1-L0) / L0 (1) The elongation was calculated by the following formula (1): The elongation calculated by the formula (1) was defined as the breaking elongation of the self-repairing layer.

[0036] If the resin substrate breaks before a crack occurs in the self-repairing layer in the tensile test, the length of the test piece at the time when the resin substrate breaks (L2) and the length of the test piece before the tensile test (L0) are calculated. 100×(L2-L0) / L0 (2) The elongation rate was calculated by the following.

[0037] In addition, the stress applied to the test piece at the point when a crack occurred in either the resin substrate or the self-repairing layer, or when either the resin substrate or the self-repairing layer broke, was defined as the breaking strength (unit: MPa) of the self-repairing sheet.

[0038] - Punching processing test - A punching test was performed using a hand press (processing device) equipped with a lower surface plate, a metal receiving die fixed to the upper side of the lower surface plate, and a punching die. The punching die had a corrosion-resistant blade with a depth of 0.4 mm and a blade angle of 40 degrees. The self-repairing sheet produced in Example 1 was attached to the upper side of the receiving die with the self-repairing layer facing upward. The attached self-repairing sheet had an area larger than the punching area of ​​the punching die.

[0039] A 0.025 mm thick polyimide film was placed on the self-repairing sheet as the workpiece, and punching was performed in an environment of 23°C. The polyimide film was replaced after each punching. Punching was performed at a speed of approximately once per second. Punching was repeated until the polyimide film could no longer be cut (specifically, cut along the shape of the punching blade). Whether the polyimide film had been cut was confirmed visually. The gap amount during punching was 0.12 mm.

[0040] In addition, as Comparative Example 1, a 125 μm thick PET resin substrate (Cosmoshine (registered trademark) A4360 manufactured by Toyobo Co., Ltd.) without a self-repairing layer was attached to a receiving mold, and a polyimide film was punched out in the same manner.

[0041] -result- For the self-repairing sheets according to Examples 1 to 6, the appearance of the self-repairing layer was visually inspected, and the results of measuring the breaking elongation and breaking strength are shown in Table 1.

[0042] [Table 1]

[0043] As shown in Table 1, foaming was observed throughout the self-repairing layer of the self-repairing sheet of Example 1. No foaming was observed in the self-repairing layer of the self-repairing sheets of Examples 2 to 6, but rough surfaces (yellow peel) were observed.

[0044] In the self-repairing sheet according to Example 1, the flexibility of the self-repairing layer was so high that the resin substrate broke before the self-repairing layer in both the MD and TD directions. Therefore, when the elongation was calculated using formula (2), it was 180.8% in the MD direction and 74.9% in the TD direction. The actual breaking elongation of the self-repairing layer was greater than these measured values. In all of Examples 1 to 6, the breaking elongation was 15% or more in both the MD and TD directions.

[0045] In Example 1, the elongation at break of the resin substrate was greater in the MD direction than in the TD direction, which is presumably because the resin substrate was a biaxially stretched PET film and the physical properties were less likely to be uniform in the TD and MD directions.

[0046] In Example 1, the breaking strength in the MD direction of the self-repairing sheet was 122.4 MPa, which was the stress applied to the self-repairing sheet at the time the resin substrate broke. In contrast, when the self-repairing sheet of Example 1 was pulled in the TD direction, it did not break even when a tensile stress was applied to the self-repairing sheet up to the upper limit of the testing machine, so the breaking strength of the self-repairing sheet was considered to be greater than 150.4 MPa.

[0047] In the self-repairing sheets of Examples 2 to 6, cracks occurred in the self-repairing layer in both the MD and TD directions without the resin substrate breaking. In all of Examples 2 to 6, the breaking elongation of the self-repairing layer was smaller than the breaking elongation of the resin substrate. The elongation of the self-repairing layer at the time when a crack occurred in the self-repairing layer was calculated using formula (1) to determine the breaking elongation. In all of Examples 2 to 6, the breaking elongation was 15% or more and 50% or less in both the MD and TD directions. In all of Examples 2 to 6, there was no significant difference in the breaking elongation of the self-repairing layer between the MD and TD directions.

[0048] It was confirmed that the breaking strength of the self-repairing sheets of Examples 2 to 6 was in the range of about 70 MPa to 90 MPa in the MD direction and about 90 MPa to 135 MPa in the TD direction. The reason why the breaking strength is higher in the TD direction than in the MD direction is presumed to be because the resin substrate is less likely to stretch in the TD direction.

[0049] Below, we will explain the results of the punching processing test for Example 1 and Comparative Example 1. In Comparative Example 1, in which only the resin substrate was placed on the receiving mold, only 12 punchings were possible, whereas when the self-repairing sheet of Example 1 was placed on the receiving mold, repeated processing was possible 81 times (6.75 times that of Comparative Example 1). This is thought to reflect the fact that the breaking elongation of the self-repairing layer is at least 15% or more. [Explanation of symbols]

[0050] 1,100 Processing equipment 2 Workpiece 2a Roll (workpiece) 3 Punching die (punching part) 4. Ukegata (Ukebe) 5 Self-repair sheet 30 punch holder 31 Punch Plate 32,101 Punching blade 40 Receiving plate 41 Die Plate 42 Die holder 50 Resin substrate 51 Self-healing layer 102 First roller (punching section) 103a, 103b Second roller (receiving part) 104a, 104b, 104c Conveyor rollers

Claims

1. A processing device for punching, a punching unit having a punching blade; a self-repairing sheet on which the workpiece is placed; a receiving portion for supporting the self-repairing sheet and receiving the punching blade; Equipped with The self-repairing sheet includes a sheet-like resin substrate and a self-repairing layer provided on a surface of the resin substrate facing the punched portion, A processing device for punching, wherein the self-repairing layer has a breaking elongation of 15% or more in both the MD direction and the TD direction.

2. The breaking elongation in the MD direction of the self-repair layer is smaller than the breaking elongation in the MD direction of the resin substrate, The punching processing device according to claim 1 , wherein the self-repairing layer has a breaking elongation in the transverse direction that is smaller than a breaking elongation in the transverse direction of the resin substrate.

3. The processing device for punching according to claim 1 , wherein the thickness of the self-repairing layer is 10 μm or more and 500 μm or less.

4. The punching device according to claim 1 , wherein the self-repairing layer is made of a urethane resin.

5. The punching processing device according to claim 1 , wherein the self-repairing layer is formed of a cured product of a UV-curable resin.

6. 2. The punching processing device according to claim 1, wherein the self-repairing layer is formed of a cured product of a solvent-free resin.

7. 7. The punching processing device according to claim 1, wherein the resin substrate is made of at least one material selected from the group consisting of polyester resin, polystyrene, polyethylene, and polypropylene.

Images