Side trimming method and side trimming device

Abstract

To provide a side trimming method and a side trimming device which can suppress, in a trimming of a sheet material coated with resin whose melting temperature is 200°C or less, adhesion and accumulation of resin on a surface of a cutting tool thereby achieving long life of the cutting tool.SOLUTION: A side trimming method which trims a metal strip side part of a metal strip while transferring the metal strip coated with resin whose melting temperature is 200°C or less on one surface thereof. In the method, a first cutting tool that is a rotary cutter is adjacent to the metal strip side part on the one surface and arranged at a position on the inside of the metal strip in a width direction, a second cutting tool that is a rotary cutter is arranged at the metal strip side part as an outer side of the metal strip in the width direction than the first cutting tool on the other surface of the metal strip, and the second cutting tool is relatively guided into the metal strip in a vertical direction while rotating the first cutting tool and the second cutting tool so as to trim the metal strip side part of the metal strip.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a side trimming method and a side trimming apparatus for trimming a side portion of a target material such as a metal plate coated with a resin.

Background Art

[0002] In recent years, in order to shorten the processing time of the coating process and the baking process and reduce the discharge of a large amount of solvents, a resin-coated metal plate in which a resin such as a thermoplastic film is coated on the surface of a target material such as a metal plate has been developed. The resin-coated metal plate is mainly widely used industrially as a material for beverage cans. Similar to a general cold-rolled steel strip, the resin-coated metal plate is trimmed at a side portion (edge portion) in the width direction in order to be processed into a predetermined width. Trimming is mainly performed by shearing by inserting the target material between a pair of rotatable round blades (trimmer blades).

[0003] Since the surface of the resin-coated metal plate is coated with a resin, resin adheres to the surface of the blade during trimming. Due to the deposition of the resin on the surface of the blade, the trimming performance deteriorates. Further, when the resin deposited on the surface of the blade falls off onto the surface of the target material which is the processing object, surface defects of the target material are induced. Therefore, a number of techniques for suppressing the deterioration of the trimming performance of the blade have been disclosed.

[0004] Patent Document 1 discloses a method for reducing the friction between a steel strip and a trimming round blade by applying a grinding oil to impart lubricity in order to improve the operating rate of the trimming round blade and improve the service life of the trimming round blade. Patent Document 2 discloses a technique for extending the life of a trimmer blade by adjusting the surface roughness of the trimmer blade to reduce the friction of the trimmer blade.

[0005] Furthermore, as a technique to suppress resin deposition on cutting tools, Patent Document 3 discloses a technique to prevent chips from adhering to the cutter by cooling the slitter when cutting thermoplastic resin. Patent Document 4 discloses a technique to prevent the generation of chips by blowing cooling gas when processing polyethylene resin with a laser cutter. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2003-245817 [Patent Document 2] Patent No. 4747555 [Patent Document 3] Japanese Patent Application Publication No. 53-6988 [Patent Document 4] Japanese Patent Publication No. 2014-76503 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, as disclosed in Patent Document 1, applying grinding oil to maintain trimming performance is difficult to apply to resin-coated metal sheets used for food and beverages. Furthermore, as disclosed in Patent Document 2, even if the surface roughness of the trimmer blade is adjusted, the deterioration of the trimmer blade is caused by the adhesion and accumulation of resin, so the effect on maintaining trimming performance is small. The technologies in Patent Documents 3 and 4 are technologies intended for cutting resin alone and are not suitable for trimming materials that are laminated with different materials such as resin-coated metal sheets.

[0008] In the case of resin-coated metal plates, resins such as polyethylene with a melting point of 200°C or lower are sometimes used as the resin coating on the surface of the metal plate. When trimming a resin with a melting point of 200°C or lower, the resin melts due to the frictional heat generated between the resin and the blade, and the melted resin adheres to the surface of the blade. When trimming a resin-coated metal plate, the shear resistance is greater than when trimming resin alone, resulting in greater frictional heat and making the resin more prone to melting.

[0009] This invention has been made in view of the above circumstances, and aims to provide a side trimming method and a side trimming apparatus that can suppress the adhesion and accumulation of resin on the surface of a cutting tool when trimming a target material coated with a resin having a melting point of 200°C or lower, thereby extending the lifespan of the cutting tool. [Means for solving the problem]

[0010] The gist of the present invention, which solves the above problems, is as follows. [1] A side trimming method for trimming the metal strip side portion of a metal strip while conveying a metal strip coated with a resin having a melting point of 200°C or less on one side, wherein a first cutting tool, which is a rotating blade, is positioned adjacent to the metal strip side portion on one side and on the inside in the width direction of the metal strip, and a second cutting tool, which is a rotating blade, is positioned on the other side of the metal strip on the metal strip side portion, which is on the outside in the width direction of the metal strip than the first cutting tool, and the side trimming method is performed by rotating the first cutting tool and the second cutting tool while relatively moving the second cutting tool in the vertical direction relative to the metal strip. [2] A side trimming method for trimming the side portion of a metal strip while conveying the metal strip, wherein one of the two surfaces of the metal strip is coated with a resin having a melting point of 200°C or less, a first cutting tool which is a rotating blade is positioned on the side of the metal strip adjacent to the side portion of the metal strip and on the inside in the width direction of the metal strip on the surface where the resin is detected, and a second cutting tool which is a rotating blade is positioned on the side of the metal strip on the other surface of the metal strip, outside in the width direction of the metal strip compared to the first cutting tool, and while rotating the first and second cutting tools, the second cutting tool is brought relatively into the metal strip in the vertical direction to trim the side portion of the metal strip. [3] A side trimming device for trimming the side portion of a metal strip while conveying a metal strip coated with a resin having a melting point of 200°C or less on one side, comprising: a first rotating blade positioned adjacent to the side portion of the metal strip on one side and on the inside in the width direction of the metal strip; and a second rotating blade positioned on the side portion of the metal strip on the other side of the metal strip, on the outside in the width direction of the metal strip compared to the first blade, and rotating together with the rotation of the first blade, and entering the metal strip relatively in the vertical direction to trim the side portion of the metal strip. [4] A side trimming device for trimming the side portion of a metal strip while conveying the metal strip, comprising: a resin surface detector for detecting a surface of the metal strip coated with a resin having a melting point of 200°C or less; a first rotating blade positioned adjacent to the side portion of the metal strip and on the inner side in the width direction of the metal strip on one side where the resin is detected by the resin surface detector; and a second rotating blade positioned on the other side of the metal strip, on the side portion of the metal strip which is further out in the width direction of the metal strip than the first blade, and which rotates together with the rotation of the first blade and enters the metal strip relative to the metal strip in the vertical direction to trim the side portion of the metal strip. [5] A side trimming method for trimming the sheet side portion of a sheet material having a resin with a melting point of 200°C or less on one side, wherein a first blade is positioned adjacent to the sheet side portion on the one side and on the inside in the width direction of the sheet material, and a second blade is positioned on the other side of the sheet material on the sheet side portion which is further outside in the width direction of the sheet material than the first blade, and the second blade is moved in the vertical direction in the direction of the first blade to trim the sheet side portion of the sheet material. [6] A side trimming method for trimming the sheet side portion of a sheet material, comprising: detecting one of the two surfaces of the sheet material that is coated with a resin having a melting point of 200°C or less; positioning a first blade adjacent to the sheet side portion on the surface where the resin is detected and on the inside in the width direction of the sheet material; positioning a second blade on the other surface of the sheet material that is on the sheet side portion further out in the width direction of the sheet material than the first blade; and moving the second blade in the vertical direction in the direction of the first blade to trim the sheet side portion of the sheet material. [7] A side trimming device for trimming the sheet side portion of a sheet material having a resin with a melting point of 200°C or less on one side, comprising: a first blade positioned adjacent to the sheet side portion on the one side and on the inside in the width direction of the sheet material; and a second blade positioned on the other side of the sheet material, on the sheet side portion which is further out in the width direction of the sheet material than the first blade, and which moves in the vertical direction in the direction of the position of the first blade to trim the sheet side portion of the sheet material. A side trimming device for trimming the side portion of a sheet material, comprising: a resin surface detector for detecting a surface of the sheet material coated with a resin having a melting point of 200°C or lower on both sides of the sheet material; a first cutting tool disposed at a position adjacent to the side portion of the sheet material and inside in the width direction of the sheet material on one surface where the resin is detected by the resin surface detector; and a second cutting tool disposed on the other surface of the sheet material at the side portion of the sheet material outside in the width direction of the sheet material than the first cutting tool, and moving in a direction in which the first cutting tool is located in the vertical direction to trim the side portion of the sheet material.

Advantages of the Invention

[0011] According to the present invention, in trimming a target material coated with a resin having a melting point of 200°C or lower, adhesion and deposition of the resin on the surface of the cutting tool can be suppressed, and the long life of the cutting tool can be achieved.

Brief Description of the Drawings

[0012] [Figure 1] It is a schematic cross-sectional view showing the state of a cross-section when trimming a target material coated with polypropylene or polyethylene terephthalate. [Figure 2] It is a schematic side view showing an example of the side trimming device of the first embodiment. [Figure 3] It is a schematic front view showing an example of the side trimming device of the first embodiment. [Figure 4] It is a schematic enlarged front view showing the positional relationship between the metal strip and the cutting tool during trimming in the first embodiment. [Figure 5] It is a schematic front view showing an example of the side trimming device of the second embodiment. <​​​​​​​​Referring to FIG. 1, matters considered by the present inventor will be described. The present inventor focused on the relationship among the position where burrs (flash) occur during trimming, the surface coated with resin, and the melting point (° C) of the coated resin in a target material such as a metal plate coated with resin. Then, a technique for suppressing the adhesion and deposition of resin on the surface of a cutting tool such as a round blade was studied.

[0014] After trimming a target material coated with polyethylene terephthalate having a melting point exceeding 200° C as the resin and a target material coated with polypropylene having a melting point of 200° C or less as the resin, the present inventor observed the surface of the cutting tool used for trimming. Resin adhesion and deposition were confirmed on the surface of the cutting tool that trimmed the target material coated with polypropylene. On the other hand, almost no resin adhesion and deposition on the surface were observed for the cutting tool that trimmed the target material coated with polyethylene terephthalate.

[0015] Next, observation of the cross-sections of both target materials after trimming was carried out. As shown in FIG. 1(a), it was observed that in the target material V coated with polypropylene M, the resin (polypropylene M) greatly invaded in the direction (shearing direction) where the burr E appears. On the other hand, as shown in FIG. 1(b), almost no invasion of the resin (polyethylene terephthalate N) into the cross-section was observed in the target material V coated with polyethylene terephthalate N.

[0016] From these results, it was presumed that the adhesion and deposition of resin on the cutting tool were caused by the fact that, as shown in FIG. 1(a), the resin having a melting point of 200° C or less softened and melted due to the frictional heat generated by contact with the cutting tool during trimming, and the melted resin invaded the cross-section and adhered to the cutting tool.

[0017] Therefore, when a resin with a melting point of 200°C or less (hereinafter also referred to as "low-melting-point resin") is coated on one side of the target material V, it was found that the penetration of the low-melting-point resin into the shear surface can be suppressed by performing trimming while avoiding contact between the blade and the low-melting-point resin, which would cause the resin to soften and melt. Furthermore, even when both sides of the target material V are coated with resin, and one side is coated with low-melting-point resin, it was found that the penetration of the low-melting-point resin into the shear surface can be suppressed by performing trimming while avoiding contact between the blade and the low-melting-point resin, which would cause the resin to soften and melt. In addition, it was found that if the penetration of the low-melting-point resin into the shear surface can be suppressed during trimming, the adhesion and accumulation of resin on the surface of the blade can be suppressed.

[0018] Based on these findings, a low-melting-point resin (e.g., "Polypropylene M") was coated on one side of the target material V, and the trimming was performed while avoiding contact between the blade and the low-melting-point resin, which would cause softening and melting of the resin. The results are shown in Figure 1(c). As shown in Figure 1(c), it was confirmed that softening and melting of the low-melting-point resin caused by contact (friction) between the blade and the low-melting-point resin were avoided, and the penetration of the low-melting-point resin into the shear surface was significantly suppressed.

[0019] <First Embodiment> The present invention will be described below through embodiments of the present invention. Referring to Figures 2 and 3, the configuration of the side trimming device 20, which is the first embodiment of the present invention, will be described. Figure 2 shows a schematic side view of the side trimming device 20. Figure 3 shows a schematic front view of the side trimming device 20. The metal strip F described below is an example of the target material V mentioned above. The metal strip F is conveyed along the metal strip conveying direction W by conveying rolls or the like. In the first embodiment, the method of applying the metal strip F as the target material V to be trimmed will be described, but as the target material V to be trimmed, sheet materials such as aluminum plates or mild steel plates, which are metal plates widely used as container materials, may also be applied.

[0020] As shown in Figure 2, the side trimming device 20 has an upper blade 11 and a lower blade 12. The upper blade 11 and the lower blade 12 may be rotating blades that rotate when trimming the metal strip F. The upper blade 11 and the lower blade 12 are fixed in their vertical positions when trimming the metal strip F. As shown in the schematic side view in Figure 2, the upper blade 11 and the lower blade 12 have a region that partially overlaps in the vertical direction. The overlapping region of the upper blade 11 and the lower blade 12 begins at position X along the metal strip conveying direction W, and the vertical overlap is maximized at position Y.

[0021] The metal strip F is transported along the metal strip transport direction W and fed into the upper cutting tool 11 and the lower cutting tool 12, which have overlapping areas and whose vertical positions are fixed. Then, trimming is performed by the upper cutting tool 11 and the lower cutting tool 12.

[0022] Figure 3(a) shows the state in the side trimming device 20 for trimming a metal strip F coated with a low-melting-point resin R, where the metal strip F being transported along the metal strip transport direction W has reached position X where the vertical overlap of the upper blade 11 and the lower blade 12 begins, and trimming of the metal strip F has begun (hereinafter also referred to as the "start time"). Figure 3(b) shows the state in the side trimming device 20 immediately after the metal strip F being transported along the metal strip transport direction W has reached position Y where the vertical overlap of the upper blade 11 and the lower blade 12 is maximum, and the metal strip F has been trimmed by the pair of blades (upper blade 11 and lower blade 12) (hereinafter also referred to as the "end time").

[0023] As shown in Figures 3(a) and 3(b), when trimming is performed with the upper blade 11 and the lower blade 12, the metal strip F is divided into a metal main body portion F1 that is used as a product and a metal strip side portion F2 that is discarded. The metal strip side portion F2 is the portion that occupies a range of approximately 5 to 15 mm in the width direction A of the metal strip F, extending inward from the edge of the metal strip F.

[0024] In the embodiment shown in Figure 3, the low-melting-point resin R is applied to the upper surface of the metal strip F, and then trimming is performed. As mentioned earlier, the low-melting-point resin R (a resin with a melting point of 200°C or less) softens and melts due to frictional heat generated by contact with the blade during trimming. Therefore, this embodiment has a distinctive positional relationship between the surface (upper or lower surface) of the metal strip F to which the low-melting-point resin R is applied and the upper blade 11 and the lower blade 12, which will be explained in detail below.

[0025] As shown in Figure 3(a), at the start of trimming, the metal strip F is first brought into the side trimming device 20 so that the upper surface of the metal strip F is coated with the low-melting-point resin R. Then, in the width direction A of the metal strip F, the lower blade 12 is positioned below the metal strip side portion F2 to be trimmed. In addition, above the metal body portion F1 which will be used as a product after trimming, the upper blade 11 is positioned adjacent to the metal strip side portion F2 to be trimmed and on the inside of the width direction A of the metal strip F.

[0026] Then, as shown in Figure 3(b), which is the end of the trimming process, the lower blade 12 enters the metal strip F relative to it in the vertical direction, trimming the metal strip F and dividing it into the metal body portion F1 and the metal strip side portion F2. In other words, although the upper blade 11 is fixed in the vertical direction, as the metal strip F is transported in the metal strip transport direction W, the upper cutting edge of the lower blade 12 enters the metal strip F relative to it.

[0027] Here, the metal body F1 is kept on a conveying line such as a belt conveyor (not shown), so its vertical position is fixed during trimming by the upper blade 11 and the lower blade 12. On the other hand, the metal strip side portion F2 being trimmed is in contact only with the lower blade 12 during trimming, so it moves upward simultaneously with the trimming and is completely separated at the end of trimming, as shown in Figure 3(b).

[0028] As mentioned above, low-melting-point resins (resins with a melting point of 200°C or less) are affected by frictional heat when in contact with a blade, causing them to soften and melt. However, in this embodiment shown in Figure 3, contact between the lower blade 12, which enters relatively in the vertical direction, and the low-melting-point resin R is avoided. In other words, during trimming, by positioning the blade (lower blade 12 in this embodiment) that enters relatively in the vertical direction on a surface (lower surface) other than the surface (upper surface) covered with the low-melting-point resin R, softening and melting of the low-melting-point resin R can be suppressed. Consequently, the penetration of softened and melted resin into the shear surface is suppressed, and the adhesion and accumulation of resin on the blade can also be suppressed.

[0029] In other words, when trimming the metal strip F, first, on one side coated with the low-melting-point resin R, the first cutting tool (upper cutting tool 11) is positioned adjacent to the side portion F2 of the metal strip F and on the inside in the width direction A of the metal strip F, while on the other side of the metal strip F, the second cutting tool (lower cutting tool 12) is positioned on the side portion F2 of the metal strip F, which is outside the width direction A of the metal strip F compared to the first cutting tool (upper cutting tool 11). Then, while rotating the first cutting tool (upper cutting tool 11) and the second cutting tool (lower cutting tool 12), the second cutting tool (lower cutting tool 12) is brought relatively into the metal strip F in the vertical direction to trim the side portion F2 of the metal strip F, thereby suppressing the adhesion and accumulation of resin on the cutting tools.

[0030] Next, we will explain in detail, using Figure 4(a), the positional relationship between the metal body F1, the metal strip side F2, and the pair of blades (upper blade 11 and lower blade 12) during the period from the start of trimming shown in Figure 3(a) to the end of trimming shown in Figure 3(b) (hereinafter referred to as the "intermediate point").

[0031] As shown in Figure 4(a), it can be confirmed that the lower cutting tool 12, positioned on the other side (bottom surface) of the metal strip F that is not coated with the low-melting-point resin R, suppresses resin adhesion and accumulation at the intermediate point of trimming. Furthermore, the trimming process generates burrs on the side (top surface) coated with the low-melting-point resin R, suppressing the penetration of the low-melting-point resin R into the shear surface.

[0032] Next, we will explain the case where a metal strip F coated with resin on both sides is trimmed, using Figures 4(b) and 4(c) which show the state at an intermediate point in the trimming process. Figure 4(b) shows the state where the trimming has been completed without the resin penetrating the shear surface, and Figure 4(c) shows the state where the resin has penetrated the shear surface.

[0033] Figure 4(b) shows a metal strip F coated with a resin T (hereinafter also referred to as "high-melting-point resin") having a melting point exceeding 200°C on its lower surface and a low-melting-point resin R on its upper surface, being trimmed using a pair of blades (upper blade 11 and lower blade 12). In Figure 4(b), contact between the lower blade 12, which enters relatively in the vertical direction, and the low-melting-point resin R is avoided. As a result, softening and melting of the low-melting-point resin R is suppressed, penetration of the softened and melted resin into the shear surface is suppressed, and adhesion and accumulation of resin on the blades are also suppressed. Furthermore, as a result of the trimming, burrs are generated on one of the surfaces (upper surface) coated with the low-melting-point resin R, which suppresses penetration of the low-melting-point resin R into the shear surface.

[0034] On the other hand, Figure 4(c) shows a metal strip F coated with a low-melting-point resin R on its lower surface and a high-melting-point resin T on its upper surface being trimmed using a pair of blades (upper blade 11 and lower blade 12). As shown in Figure 4(c), during trimming, the lower blade 12, which enters relatively in the vertical direction, comes into contact with the low-melting-point resin R, and the frictional force resulting from this contact causes the low-melting-point resin R to soften and melt. As a result, the softened and melted resin penetrates the shear surface, inducing the adhesion and accumulation of resin on the surface of the blades.

[0035] Therefore, as explained using Figures 4(b) and 4(c), even when trimming a metal strip F coated with resin on both sides, the adhesion and accumulation of resin on the blade can be suppressed in the same manner as described above using Figures 3 and 4(a). In other words, when trimming the metal strip F, first, on one side coated with the low-melting-point resin R, the first blade (upper blade 11) is positioned adjacent to the side portion F2 of the metal strip F and on the inside in the width direction A of the metal strip F, while on the other side of the metal strip F, the second blade (lower blade 12) is positioned on the side portion F2 of the metal strip F, which is outside the width direction A of the metal strip F compared to the first blade (upper blade 11). Subsequently, while rotating the first blade (upper blade 11) and the second blade (lower blade 12), the second blade (lower blade 12) is brought relatively into contact with the metal strip F in the vertical direction, thereby trimming the metal strip side portion F2 of the metal strip F, and thus preventing resin from adhering to and accumulating on the blades.

[0036] Here, the configuration of the side trimming device 20 in Figure 3 is described as follows: during trimming, a first blade (upper blade 11) is positioned adjacent to the side portion F2 of the metal strip F on one side (upper surface) covered with the low-melting-point resin R, and on the inner side in the width direction A of the metal strip F; and a second blade (lower blade 12) is positioned on the other side (lower surface) of the metal strip F on the side portion F2, which is further out in the width direction A of the metal strip F than the first blade (upper blade 11).

[0037] Furthermore, by arranging the material as described above during trimming, contact between the lower blade 12, which enters relatively in the vertical direction, and the low-melting-point resin R is avoided, thereby suppressing the softening and melting of the low-melting-point resin R. This also prevents the softened and melted resin from entering the shear surface, and suppresses the adhesion and accumulation of resin on the blade. In other words, as long as contact between the blade, which enters relatively in the vertical direction, and the low-melting-point resin R is avoided, the same effect can be obtained.

[0038] Therefore, when the low-melting-point resin R is loaded onto the underside of the metal strip F and then brought into the side trimming device 20, a similar effect can be obtained by adjusting the position of the pair of blades (upper blade 11 and lower blade 12) relative to the metal strip F.

[0039] Specifically, first, on one side (bottom surface) coated with the low-melting-point resin R, the first cutting tool (lower cutting tool 12) is positioned adjacent to the metal strip side portion F2 and on the inside in the width direction A of the metal strip F. Simultaneously, on the other side (top surface) of the metal strip F, the second cutting tool (upper cutting tool 11) is positioned on the metal strip side portion F2, which is further out in the width direction A of the metal strip F than the first cutting tool (lower cutting tool 12). Then, while rotating the first cutting tool (lower cutting tool 12) and the second cutting tool (upper cutting tool 11), the second cutting tool (upper cutting tool 11) is brought relatively into the metal strip F in the vertical direction to trim the metal strip side portion F2 of the metal strip F, thereby suppressing the adhesion and accumulation of resin on the cutting tools.

[0040] In other words, when trimming a metal strip F coated with a low-melting-point resin R on its upper surface, as shown in Figure 3, the upper blade 11 is positioned adjacent to the side portion F2 of the metal strip and inside the width direction A of the metal strip F, and the lower blade 12, which enters relatively in the vertical direction, is positioned on the side portion F2 of the metal strip. On the other hand, when trimming a metal strip F coated with a low-melting-point resin R on its lower surface, the lower blade 12 is positioned adjacent to the side portion F2 of the metal strip and inside the width direction A of the metal strip F, and the upper blade 11, which enters relatively in the vertical direction, is positioned on the side portion F2 of the metal strip.

[0041] In other words, based on the surface (upper or lower surface) of the metal strip F coated with the low-melting-point resin R, the upper cutting tool 11 and the lower cutting tool 12 can be moved in opposite directions in the width direction A of the metal strip F to correspond to each other.

[0042] Therefore, regardless of whether the metal strip F is coated with a low-melting-point resin R on its upper surface or on its lower surface, a separately provided resin surface detector can detect the surface coated with the low-melting-point resin R, and based on the detection result, the positions of the upper blade 11 and the lower blade 12 in the width direction A of the metal strip F can be adjusted.

[0043] In this case, more specifically, a mechanism is provided to adjust the axial length of the upper and lower spindle motors (not shown) that hold the upper cutting tool 11 and the lower cutting tool 12, and by adjusting the axial length, the positions of the upper cutting tool 11 and the lower cutting tool 12 in the width direction A of the metal strip F can be adjusted.

[0044] In this embodiment, the upper cutting tool 11 and the lower cutting tool 12 are preferably a pair of rotary blades arranged opposite each other in the vertical direction, which are trimmer blades that enable trimming of the metal strip that is the workpiece.

[0045] Furthermore, as described using Figure 4(a), the size of burrs that occur on one side (the upper surface) coated with the low-melting-point resin R due to trimming can be adjusted by adjusting the gap (clearance) between the upper cutting tool 11 and the lower cutting tool 12 in the horizontal direction (width direction A).

[0046] <Second Embodiment> Next, the configuration of the side trimming device 10, which is a second embodiment of the present invention, will be described with reference to Figure 5. Figure 5 shows a schematic front view of the side trimming device 10. The sheet material S described below is an example of the target material V mentioned earlier.

[0047] In the second embodiment, the side trimming device 10 trims the sheet material S placed (sandwiched) between a pair of blades (upper blade 1 and lower blade 2) by having one blade (upper blade 1 or lower blade 2) move toward the other blade (upper blade 1 or lower blade 2).

[0048] Figure 5(a) shows the state of a side trimming device 10 for trimming a sheet material S coated with a low-melting-point resin R, immediately before trimming the sheet material S, with a pair of blades (upper blade 1 and lower blade 2) positioned relative to the sheet material S. Figure 5(b) shows the state of the side trimming device 10 immediately after trimming the sheet material S with the pair of blades (upper blade 1 and lower blade 2).

[0049] As shown in Figure 5(a), when trimming is performed with the side trimming device 10, the upper blade 1 and the lower blade 2 are positioned on the sheet material S so as to sandwich the sheet material S from above and below. Then, as shown in Figure 5(b), when trimming is performed by the upper blade 1 and the lower blade 2, the sheet material S is divided into the sheet body portion S1 which is used as a product and the sheet side portion S2 which is discarded. The sheet side portion S2 is the part that occupies a range of, for example, about 5 to 15 mm in the width direction A of the sheet material S, extending inward from the edge of the sheet material S.

[0050] In the embodiment shown in Figure 5, the low-melting-point resin R is applied to the upper surface of the sheet material S, and then trimming is performed. As mentioned earlier, the low-melting-point resin R (a resin with a melting point of 200°C or less) softens and melts due to frictional heat generated by contact with the blade during trimming. Therefore, this embodiment has a distinctive positional relationship between the surface (upper or lower surface) of the sheet material S to which the low-melting-point resin R is applied and the upper blade 1 and lower blade 2, which will be explained in detail below.

[0051] As shown in Figure 5(a), immediately before trimming, the sheet material S is first inserted into the side trimming device 10 so that the upper surface of the sheet material S is covered with the low-melting-point resin R. Then, in the width direction A of the sheet material S, the lower blade 2 is positioned below the sheet side portion S2 to be trimmed. Furthermore, above the sheet body portion S1 which will be used as a product after trimming, the upper blade 1 is positioned adjacent to the sheet side portion S2 to be trimmed and on the inside of the width direction A of the sheet material S.

[0052] Then, as shown in Figure 5(b), the pair of blades move closer together so that the distance between the upper blade 1 and the lower blade 2 decreases in the vertical direction, thereby trimming the sheet material S and dividing it into the sheet body portion S1 and the sheet side portion S2.

[0053] Here, the sheet body S1 is kept on a conveyor belt or other transport line (not shown), so its vertical position is fixed during trimming by the upper blade 1 and lower blade 2. On the other hand, the sheet side portion S2 being trimmed is in contact only with the lower blade 2 during trimming, so it moves upward simultaneously with the trimming.

[0054] As mentioned earlier, low-melting-point resins (resins with a melting point of 200°C or less) are affected by frictional heat when in contact with a blade, causing them to soften and melt. However, in this embodiment shown in Figure 5, contact between the moving lower blade 2 and the low-melting-point resin R is avoided. In other words, during trimming, by positioning the moving blade (lower blade 2 in this embodiment) on a surface (lower surface) separate from the surface (upper surface) covered with the low-melting-point resin R, softening and melting of the low-melting-point resin R can be suppressed. Consequently, the penetration of softened and melted resin into the shear surface is suppressed, and the adhesion and accumulation of resin on the blade can also be suppressed.

[0055] In other words, when trimming the sheet material S, first, on one side coated with the low-melting-point resin R, the first blade (upper blade 1) is positioned adjacent to the sheet side portion S2 and on the inside in the width direction A of the sheet material S, while on the other side of the sheet material S, the second blade (lower blade 2) is positioned on the sheet side portion S2, which is outside the width direction A of the sheet material S than the first blade (upper blade 1). Then, by moving the second blade (lower blade 2) in the direction of the first blade (upper blade 1) to trim the sheet side portion S2 of the sheet material S, the adhesion and accumulation of resin on the blades can be suppressed.

[0056] Next, the positional relationship between the sheet body S1, the sheet side portion S2, and the pair of blades (upper blade 1 and lower blade 2) in the state immediately after trimming shown in Figure 5(b) will be explained in detail using Figure 6(a).

[0057] As shown in Figure 6(a), it can be confirmed that the lower cutting tool 2, positioned on the other side (bottom surface) of the sheet material S that is not coated with the low-melting-point resin R, showed suppressed resin adhesion and accumulation after trimming. Furthermore, the trimming process generated burrs on the side (top surface) coated with the low-melting-point resin R, suppressing the penetration of the low-melting-point resin R into the shear surface.

[0058] Next, we will explain the case where a sheet material S coated with resin on both sides is trimmed, using Figures 6(b) and 6(c). Figure 6(b) shows the state after trimming without the resin entering the shear surface, and Figure 6(c) shows the state after the resin has entered the shear surface.

[0059] Figure 6(b) shows a sheet material S, which is coated on the lower surface with a resin T having a melting point exceeding 200°C (hereinafter also referred to as "high-melting-point resin") and on the upper surface with a low-melting-point resin R, being trimmed using a pair of blades (upper blade 1 and lower blade 2). In Figure 6(b), contact between the moving lower blade 2 and the low-melting-point resin R is avoided. As a result, softening and melting of the low-melting-point resin R is suppressed, the penetration of softened and melted resin into the shear surface is suppressed, and the adhesion and accumulation of resin on the blades is also suppressed. Furthermore, as a result of the trimming, burrs are generated on one of the surfaces (upper surface) coated with the low-melting-point resin R, which suppresses the penetration of the low-melting-point resin R into the shear surface.

[0060] On the other hand, Figure 6(c) shows a sheet material S coated with a low-melting-point resin R on its lower surface and a high-melting-point resin T on its upper surface, trimmed using a pair of blades (upper blade 1 and lower blade 2). As shown in Figure 6(c), during trimming, the moving lower blade 2 comes into contact with the low-melting-point resin R, and the frictional force resulting from this contact causes the low-melting-point resin R to soften and melt. As a result, the softened and melted resin penetrates the shear surface, inducing the adhesion and accumulation of resin on the surface of the blades.

[0061] Therefore, as explained using Figures 6(b) and 6(c), even when trimming a sheet material S coated with resin on both sides, the adhesion and accumulation of resin on the blade can be suppressed in the same way as described above using Figures 5 and 6(a). In other words, when trimming the sheet material S, first, on one side coated with low-melting-point resin R, the first blade (upper blade 1) is positioned adjacent to the sheet side portion S2 and on the inside in the width direction A of the sheet material S, and on the other side of the sheet material S, the second blade (lower blade 2) is positioned on the sheet side portion S2, which is outside the width direction A of the sheet material S than the first blade (upper blade 1). Then, by moving the second blade (lower blade 2) in the direction of the first blade (upper blade 1) and trimming the sheet side portion S2 of the sheet material S, the adhesion and accumulation of resin on the blade can be suppressed.

[0062] Here, the configuration of the side trimming device 10 in Figure 5 is described as follows: during trimming, a first blade (upper blade 1) is positioned adjacent to the sheet side portion S2 and on the inside of the width direction A of the sheet material S on one side (upper surface) covered with the low-melting-point resin R, and a second blade (lower blade 2) is positioned on the other side (lower surface) of the sheet material S, on the sheet side portion S2 which is outside the width direction A of the sheet material S compared to the first blade (upper blade 1).

[0063] Furthermore, by arranging the material as described above during trimming, contact between the moving lower blade 2 and the low-melting-point resin R is avoided, suppressing the softening and melting of the low-melting-point resin R. This also prevents the softened and melted resin from penetrating the shear surface, and suppresses the adhesion and accumulation of resin on the blade. In other words, as long as contact between the moving blade and the low-melting-point resin R is avoided, the same effect can be obtained.

[0064] Therefore, when the sheet material S is inserted into the side trimming device 10 with the low-melting-point resin R covering its lower surface, a similar effect can be obtained by adjusting the position of the pair of blades (upper blade 1 and lower blade 2) relative to the sheet material S.

[0065] Specifically, first, on one side (bottom surface) coated with the low-melting-point resin R, the first cutting tool (lower cutting tool 2) is positioned adjacent to the sheet side portion S2 and on the inside in the width direction A of the sheet material S. Simultaneously, on the other side (top surface) of the sheet material S, the second cutting tool (upper cutting tool 1) is positioned on the sheet side portion S2, which is further out in the width direction A of the sheet material S than the first cutting tool (lower cutting tool 2). Subsequently, the second cutting tool (upper cutting tool 1) is moved in the direction of the first cutting tool (lower cutting tool 2) to trim the sheet side portion S2 of the sheet material S, thereby suppressing the adhesion and accumulation of resin on the cutting tools.

[0066] In other words, when trimming a sheet material S coated with a low-melting-point resin R on its upper surface, as shown in Figure 5, the upper blade 1 is positioned adjacent to the sheet side portion S2 and on the inside of the width direction A of the sheet material S, and the lower blade 2, which moves toward the upper blade 1, is positioned on the sheet side portion S2. On the other hand, when trimming a sheet material S coated with a low-melting-point resin S on its lower surface, the lower blade 2 is positioned adjacent to the sheet side portion S2 and on the inside of the width direction A of the sheet material S, and the upper blade 1, which moves toward the lower blade 2, is positioned on the sheet side portion S2.

[0067] In other words, based on the surface (top or bottom) of the sheet material S covered with the low-melting-point resin R, the upper cutting tool 1 and the lower cutting tool 2 can be moved in opposite directions in the width direction A of the sheet material S to correspond to each other.

[0068] Therefore, regardless of whether the sheet material S is coated with low-melting-point resin R on its upper surface or on its lower surface, a separately provided resin surface detector can detect the surface coated with low-melting-point resin R, and based on the detection result, the positions of the upper blade 1 and lower blade 2 in the width direction A of the sheet material S can be adjusted.

[0069] In this case, more specifically, a mechanism is provided to adjust the axial length of the upper and lower spindle motors (not shown) that hold the upper cutting tool 1 and the lower cutting tool 2, and by adjusting the axial length, the positions of the upper cutting tool 1 and the lower cutting tool 2 in the width direction A of the sheet material S can be adjusted.

[0070] In this second embodiment, it is preferable to use shear blades that enable trimming of the sheet material, which is the workpiece, as the upper cutting tool 1 and the lower cutting tool 2.

[0071] Furthermore, as described using Figure 6(a), the size of burrs that occur on one side (the top surface) coated with the low-melting-point resin R due to trimming can be adjusted by adjusting the gap (clearance) between the upper cutting tool 1 and the lower cutting tool 2 in the horizontal direction (width direction A).

[0072] Here, the low-melting-point resin R (resin with a melting point of 200°C or less) in the first and second embodiments will be described. The low-melting-point resin R is not particularly limited, and polyester-based, polyolefin-based, etc., can be used. The polyester resin may be copolymerized with various dicarboxylic acid components and glycol components as long as the processability, corrosion resistance, etc. are not impaired. Examples of dicarboxylic acid components include aromatic dicarboxylic acids such as isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfondicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodium sulfisophthalic acid, and phthalic acid; aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, and fumaric acid; alicyclic dicarboxylic acids such as cyclohexanedicarboxylic acid; and oxycarboxylic acids such as p-oxybenzoic acid. Examples of glycol components include aliphatic glycols such as ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, and neopentyl glycol; alicyclic glycols such as cyclohexanedimethanol; aromatic glycols such as bisphenol A and bisphenol S; and diethylene glycol. Furthermore, to improve processability, polyolefin resins may include layers using polypropylene resins and even propylene-ethylene block copolymers. Additionally, to enhance adhesion to metal plates, a mixed resin primarily composed of adhesive polypropylene and adhesive polyethylene may be used in the lower layer.

[0073] Next, the sheet material S in the second embodiment will be described. The sheet material S is a metal plate, and can be an aluminum plate or mild steel plate, which are widely used as container materials. In addition, steel plates such as tinplate or tin-free steel can be used for surface treatment. For tinplate, the plating amount is 0.5 g / m². 2 More than 15g / m 2 The following ranges are preferred: Tin-free steel with an adhesion amount of 50 mg / m². 2 More than 200g / m 2 The metallic chromium layer is within the following range, and the amount of metallic chromium deposited is 3 mg / m². 2 More than 30g / m 2It is preferable that the surface has a chromium oxide layer within the following range. The type of steel sheet is not particularly limited as long as it can be formed into the desired shape. [Examples]

[0074] The following describes the results of trimming a target material coated with a low-melting-point resin using the side trimming device 20 of the first embodiment as an example.

[0075] The target material is 0.22 mm thick TFS (Tin-Free Steel, metal Cr layer: 120 mg / m²). 2 Cr oxide layer: 10 mg / m² in terms of metallic Cr 2 A resin with a temper degree of T3CA was used. As described in Table 1 as an example of the present invention and a comparative example, both sides or one side (top or bottom) of the target material were coated with resin by a film lamination method (film heat fusion method). The target material was then heated, and a biaxially oriented film of resin was heat-pressed onto the target material with a laminating roll. After 1 second had elapsed since heat pressing, the material was water-cooled to prepare a sample in which both sides or one side of the target material was coated with resin.

[0076] Subsequently, the prepared samples were trimmed using the side trimming device 20 shown in Figure 3, and the state of resin adhesion and accumulation on the blades was examined. The results of the examination are shown in Table 1.

[0077] [Table 1]

[0078] In Table 1, under "Resin Coating Composition," "PP" refers to polypropylene. "PE-dispersed PP" refers to polyethylene-dispersed polypropylene. "Isophthalic acid copolymer PET" refers to isophthalic acid copolymer polyethylene terephthalate. "PP" and "PE-dispersed PP" are low-melting-point resins (resins with a melting point of 200°C or less). "Isophthalic acid copolymer PET" is a high-melting-point resin (resins with a melting point exceeding 200°C).

[0079] Furthermore, in the "Adhesion or accumulation of resin on the blade" column of Table 1, the evaluation was as follows: if no adhesion or accumulation of resin was observed on the surface of the blade after trimming the sample, it was marked as "○ (Good)," and if adhesion or accumulation of resin was observed on the surface of the blade, it was marked as "× (Poor)."

[0080] Examples 1 to 3 of the present invention were configured with a low-melting-point resin, either "PE-dispersed PP" or "PP," coated on the upper surface. Based on this, the upper cutting tool was positioned on the upper surface of the target material adjacent to the side of the metal strip to be trimmed and on the inside in the width direction of the target material. Furthermore, on the lower surface of the target material, the lower cutting tool, which enters the target material relatively in the vertical direction, was positioned on the side of the metal strip and trimming was performed. As a result, contact between the lower cutting tool, which enters the target material relatively in the vertical direction, and the low-melting-point resin was avoided, suppressing softening and melting of the low-melting-point resin, preventing resin adhesion and accumulation on the cutting tool, and yielding good results.

[0081] Example 4 of the present invention uses a configuration in which the lower surface is coated with a low-melting-point resin, "PP". Based on this, the lower cutting tool was positioned on the lower surface of the target material adjacent to the side portion of the metal strip to be trimmed and on the inside in the width direction of the target material. Furthermore, on the upper surface of the target material, the upper cutting tool, which enters the target material relatively in the vertical direction, was positioned on the side portion of the metal strip and trimming was performed. As a result, contact between the upper cutting tool, which enters the target material relatively in the vertical direction, and the low-melting-point resin was avoided, suppressing the softening and melting of the low-melting-point resin, preventing resin from adhering to or accumulating on the cutting tool, and resulting in good results.

[0082] Comparative Examples 1-3 were constructed with a low-melting-point resin, either "PE-dispersed PP" or "PP," coated on the upper surface. On the lower surface of the target material, the lower cutting tool was positioned adjacent to the side of the metal strip to be trimmed and on the inner side in the width direction of the target material. Furthermore, on the upper surface of the target material, the upper cutting tool, which entered the target material relatively in the vertical direction, was positioned on the side of the metal strip and trimming was performed. As a result, contact occurred between the upper cutting tool, which entered the target material relatively in the vertical direction, and the low-melting-point resin, causing softening and melting of the low-melting-point resin. The low-melting-point resin penetrated the shear surface, resulting in adhesion and accumulation on the surface of the cutting tool.

[0083] From the above, by using the side trimming method and side trimming apparatus according to the present invention, even when trimming a target material coated with a low-melting-point resin, it is possible to suppress the adhesion and accumulation of resin on the cutting tool used for trimming, thereby suppressing the deterioration of the trimming performance of the cutting tool and extending the lifespan of the cutting tool. Furthermore, productivity in the processing line can be maintained. [Explanation of Symbols]

[0084] 1. 11 Upper blade 2.12 Lower blade 10, 20 Side trimming device A (of the target material V) width direction E Bari (return) F Metal strip F1 Metal body F2 Metal strip side section M Polypropylene N Polyethylene terephthalate R Low melting point resin S sheet material S1 Seat Body S2 Seat Side Section T High melting point resin W Metal strip conveying direction V Target material X,Y position

Claims

1. A side trimming method for trimming the metal strip side portion while transporting a metal strip in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, On one of the aforementioned surfaces, a first cutting tool, which is a rotating blade, is positioned adjacent to the side portion of the metal strip and on the inner side in the width direction of the metal strip, and on the other surface of the metal strip, a second cutting tool, which is a rotating blade, is positioned on the side portion of the metal strip, which is on the outer side in the width direction of the metal strip than the first cutting tool. A side trimming method comprising rotating the first and second cutting tools while relatively inserting the second cutting tool into the metal strip in the vertical direction to trim the side portion of the metal strip.

2. A side trimming method for trimming the metal strip side portion of a metal strip while conveying a metal strip in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, Of the two surfaces of the aforementioned metal strip, the surface coated with a resin having a melting point of 200°C or less is detected. On the one surface where the resin is detected, a first blade, which is a rotating blade, is positioned adjacent to the side portion of the metal strip and on the inside in the width direction of the metal strip; and on the other surface of the metal strip, a second blade, which is a rotating blade, is positioned on the side portion of the metal strip, which is on the outside in the width direction of the metal strip than the first blade. A side trimming method comprising rotating the first and second cutting tools while relatively inserting the second cutting tool into the metal strip in the vertical direction to trim the side portion of the metal strip.

3. A side trimming device that trims the side portion of a metal strip while conveying a metal strip in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, The first cutting tool of the rotating blade is positioned adjacent to the side portion of the metal strip on one of the aforementioned surfaces and on the inner side in the width direction of the metal strip, A rotating blade is positioned on the other side of the metal strip, on the metal strip side portion which is outside the width direction of the metal strip compared to the first blade, and a second blade rotates together with the rotation of the first blade and enters the metal strip relative to the metal strip in the vertical direction to trim the metal strip side portion of the metal strip. A side trimming device having the following features.

4. A side trimming device for trimming the metal strip side portion of a metal strip while conveying a metal strip in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, A resin surface detector that detects the side of the metal strip that is coated with a resin having a melting point of 200°C or less, The resin surface detector detects the resin on one of the surfaces, and the first cutting tool of the rotating blade is positioned adjacent to the side portion of the metal strip and on the inner side in the width direction of the metal strip. A rotating blade is positioned on the other side of the metal strip, on the metal strip side portion which is outside the width direction of the metal strip compared to the first blade, and a second blade rotates together with the rotation of the first blade and enters the metal strip relative to the metal strip in the vertical direction to trim the metal strip side portion of the metal strip. A side trimming device having the following features.

5. A side trimming method for trimming the sheet side portion of a sheet material in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, On one of the aforementioned surfaces, the first cutting tool is positioned adjacent to the sheet side portion and on the inner side in the width direction of the sheet material, and on the other surface of the sheet material, the second cutting tool is positioned on the sheet side portion which is on the outer side in the width direction of the sheet material than the first cutting tool. A side trimming method comprising moving the second blade in the vertical direction in the direction of the first blade to trim the sheet side portion of the sheet material.

6. A side trimming method for trimming the sheet side portion of a sheet material in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, Of the two surfaces of the sheet material, the surface coated with a resin having a melting point of 200°C or less is detected. The first blade is positioned on one side of the sheet material where the resin is detected, adjacent to the sheet side portion and on the inner side in the width direction of the sheet material, and the second blade is positioned on the other side of the sheet material, on the sheet side portion which is further out in the width direction of the sheet material than the first blade. A side trimming method comprising moving the second blade in the vertical direction in the direction of the first blade to trim the sheet side portion of the sheet material.

7. A side trimming device for trimming the sheet side portion of a sheet material in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, A first cutting tool is positioned adjacent to the sheet side portion on one of the aforementioned surfaces and on the inner side in the width direction of the sheet material, A second blade is positioned on the other side of the sheet material, on the sheet side portion which is outside the width direction of the sheet material compared to the first blade, and moves in the vertical direction in the direction of the first blade to trim the sheet side portion of the sheet material. A side trimming device having the following features.

8. A side trimming device for trimming the sheet side portion of a sheet material in which one side is coated with a resin having a melting point of 200°C or less and the other side is coated with a resin having a melting point exceeding 200°C, A resin surface detector that detects the side of the sheet material that is coated with a resin having a melting point of 200°C or less, A first cutting tool is positioned adjacent to the sheet side portion on one of the surfaces where the resin is detected by the resin surface detector, and on the inner side in the width direction of the sheet material, A second blade is positioned on the other side of the sheet material, on the sheet side portion which is outside the width direction of the sheet material compared to the first blade, and moves in the vertical direction in the direction of the first blade to trim the sheet side portion of the sheet material. A side trimming device having the following features.

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