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 device for trimming a side portion of a workpiece such as a resin-coated metal plate. [Background technology]

[0002] In recent years, resin-coated metal sheets have been developed in which the surface of a target material such as a metal plate is coated with a resin such as a thermoplastic film in order to shorten the processing time of the painting and baking processes and reduce the large amount of solvent emissions. Resin-coated metal sheets are widely used industrially, mainly as materials for beverage cans. Like general cold-rolled steel strips, resin-coated metal sheets are trimmed at the sides (edges) in the width direction in order to process them to a specified width. Trimming is mainly performed by inserting the target material between a pair of rotatable circular blades (trimmer blades) and shearing it.

[0003] Since the surface of the resin-coated metal plate is coated with resin, the resin adheres to the surface of the blade during trimming. The trimming performance of the blade deteriorates due to the accumulation of resin on the surface. Furthermore, if the resin accumulated on the surface of the blade falls off onto the surface of the target material, which is the object to be processed, it will induce surface defects in the target material. For this reason, many technologies have been disclosed for suppressing the deterioration of the trimming performance of the blade.

[0004] Patent Document 1 discloses a method for improving the operating rate of a trimming blade by applying a grinding oil to provide lubrication to reduce friction between a steel strip and the trimming blade and thereby improving the service life of the trimming blade. Patent Document 2 discloses a technology for extending the life of a trimmer blade by adjusting the surface roughness of the trimmer blade to reduce friction of the trimmer blade.

[0005] As a technique for suppressing the accumulation of resin on a blade, Patent Document 3 discloses a technique for cooling a slitter to prevent chips from adhering to a cutter when cutting thermoplastic resin. Patent Document 4 discloses a technique for preventing 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] JP 2003-245817 A [Patent Document 2] Patent No. 4747555 [Patent Document 3] Japanese Patent Application Publication No. 53-6988 [Patent Document 4] JP 2014-76503 A Summary of the Invention [Problem to be solved by the invention]

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

[0008] Here, in resin-coated metal sheets, a resin such as polyethylene with a melting point of 200°C or less may be used as the resin that coats the surface of the metal sheet. When trimming a resin with a melting point of 200°C or less, the resin melts due to frictional heat generated between the resin and the blade, and the molten resin adheres to the surface of the blade. When trimming a resin-coated metal sheet, the shear resistance is greater than when trimming a resin alone, and therefore the frictional heat is also greater, making the resin more likely to melt.

[0009] The present invention has been made in consideration of the above circumstances, and aims to provide a side trimming method and side trimming device that can suppress the adhesion and accumulation of resin on the surface of a blade and extend the life of the blade when trimming a target material coated with resin having a melting point of 200°C or less. [Means for solving the problem]

[0010] The gist and configuration of the present invention to solve the above problems are as follows. [1] A side trimming method for conveying a metal strip coated on one side with a resin having a melting point of 200°C or less, and trimming a side portion of the metal strip, comprising: arranging a first blade which is a rotary blade adjacent to the metal strip side portion on the one side and on the inside in the width direction of the metal strip; and arranging a second blade which is a rotary blade on the other side of the metal strip on the metal strip side portion which is on the outside of the first blade in the width direction of the metal strip; and rotating the first blade and the second blade while advancing the second blade relatively in the vertical direction toward the metal strip to trim the metal strip side portion of the metal strip. [2] A side trimming method for trimming a side portion of a metal strip while transporting the metal strip, comprising the steps of: detecting one of both sides of the metal strip which is coated with a resin having a melting point of 200°C or less; positioning a first blade which is a rotating blade adjacent to the side portion of the metal strip on one side where the resin is detected and in a position inside in the width direction of the metal strip; and positioning a second blade which is a rotating blade on the other side of the metal strip on the side portion of the metal strip which is outside the first blade in the width direction of the metal strip; and rotating the first blade and the second blade while advancing the second blade relatively in the vertical direction toward the metal strip to trim the side portion of the metal strip. [3] A side trimming device which conveys a metal strip coated on one side with a resin having a melting point of 200°C or less and trims a side portion of the metal strip, the side trimming device comprising: a first blade of a rotary blade which is arranged adjacent to the metal strip side portion on the one side and in a position inside in the width direction of the metal strip; and a second blade which is a rotary blade which is arranged on the other side of the metal strip on the metal strip side portion which is outside the first blade in the width direction of the metal strip, the second blade rotating together with the first blade and entering relatively in the vertical direction against the metal strip to trim the metal strip side portion of the metal strip. [4] A side trimming device that trims a side portion of a metal strip while transporting the metal strip, the side trimming device comprising: a resin surface detector that detects which of both sides of the metal strip is coated with a resin having a melting point of 200°C or less; a first blade of a rotary blade that is adjacent to the metal strip side portion on one side where the resin is detected by the resin surface detector and is positioned inward in the width direction of the metal strip; and a second blade that is a rotary blade that is positioned on the other side of the metal strip at the metal strip side portion that is outward in the width direction of the metal strip than the first blade, and that rotates together with the rotation of the first blade and advances relatively in the vertical direction against the metal strip to trim the metal strip side portion of the metal strip. [5] A side trimming method for trimming a sheet side portion of a sheet material having one surface coated with a resin having a melting point of 200°C or less, comprising: arranging a first blade on the one surface adjacent to the sheet side portion and on the inside in the width direction of the sheet material; and arranging a second blade on the other surface of the sheet material in the sheet side portion that is on the outside of the first blade in the width direction of the sheet material; and moving the second blade in the vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material. [6] A side trimming method for trimming a sheet side portion of a sheet material, comprising: detecting one of both sides of the sheet material which 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 one side where the resin is detected and on the inside in the width direction of the sheet material; and positioning a second blade on the other side of the sheet material in the sheet side portion which is on the outside of the first blade in the width direction of the sheet material; 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 a sheet side portion of a sheet material having one surface coated with a resin having a melting point of 200°C or less, the side trimming device having: a first blade arranged adjacent to the sheet side portion on the one surface and at a position inside in the width direction of the sheet material; and a second blade arranged on the other surface of the sheet material in the sheet side portion that is outside the first blade in the width direction of the sheet material, and moving in the vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material. [8] A side trimming device for trimming a sheet side portion of a sheet material, comprising: a resin surface detector for detecting the surface of both sides of the sheet material which is coated with a resin having a melting point of 200°C or lower; a first blade arranged adjacent to the sheet side portion on one side where the resin is detected by the resin surface detector and positioned inside in the width direction of the sheet material; and a second blade arranged on the other side of the sheet material in the sheet side portion which is outside the first blade in the width direction of the sheet material, and moving in the vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material. Effect of the Invention

[0011] According to the present invention, when trimming a target material coated with resin having a melting point of 200° C. or less, adhesion and accumulation of resin on the surface of a blade can be suppressed, thereby enabling the blade to have a longer life. [Brief description of the drawings]

[0012] [Figure 1] 1 is a schematic cross-sectional view showing the state of a cross section when a target material coated with polypropylene or polyethylene terephthalate is trimmed. FIG. [Diagram 2] FIG. 2 is a schematic side view showing an example of the side trimming device according to the first embodiment. [Diagram 3] FIG. 2 is a schematic front view showing an example of the side trimming device according to the first embodiment. [Figure 4] 4 is an enlarged schematic front view showing the positional relationship between a metal strip and a blade during trimming in the first embodiment. FIG. [Diagram 5] FIG. 11 is a schematic front view showing an example of a side trimming device according to a second embodiment. [Figure 6] 13 is an enlarged schematic front view showing the positional relationship between a sheet material and a blade during trimming in the second embodiment. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] The present inventors' investigations will be described with reference to Fig. 1. The present inventors focused on the relationship between the position where burrs are formed during trimming of a target material such as a resin-coated metal plate, the surface coated with the resin, and the melting point (°C) of the coated resin. They then investigated a technique for suppressing the adhesion and accumulation of resin on the surface of a cutting tool such as a round blade.

[0014] The inventors trimmed a target material coated with polyethylene terephthalate resin having a melting point of over 200°C, and a target material coated with polypropylene resin having a melting point of 200°C or less, and then observed the surface of the blade used for trimming. The blade used to trim the target material coated with polypropylene had adhesion and accumulation of resin on the surface. On the other hand, the blade used to trim the target material coated with polyethylene terephthalate had almost no adhesion or accumulation of resin on the surface.

[0015] Next, the shear surfaces of both target materials were observed after trimming. As shown in Figure 1(a), it was observed that target material V coated with polypropylene M had a large amount of resin (polypropylene M) penetrating in the direction of burr E (shear direction). On the other hand, as shown in Figure 1(b), almost no resin (polyethylene terephthalate N) was observed penetrating into the shear surface of target material V coated with polyethylene terephthalate N.

[0016] From these results, it was inferred that the adhesion and accumulation of resin on the blade was caused by the frictional heat generated by contact with the blade during trimming, which softened and melted the resin with a melting point of 200°C or less, and the molten resin penetrated the sheared surface and adhered to the blade, as shown in Figure 1(a).

[0017] Therefore, when one side of the target material V is coated with a resin having a melting point of 200°C or less (hereinafter also referred to as "low melting point resin"), it has been found that the low melting point resin can be prevented from penetrating the sheared surface by performing trimming while avoiding contact between the blade and the low melting point resin, which causes the resin to soften and melt. In addition, when both sides of the target material V are coated with resin and only one side of the resin is coated with a low melting point resin, it has been found that the low melting point resin can be prevented from penetrating the sheared surface by performing trimming while avoiding contact between the blade and the low melting point resin, which causes the resin to soften and melt. It has also been found that if the low melting point resin can be prevented from penetrating the sheared surface during trimming, adhesion and accumulation of the resin on the surface of the blade can be prevented.

[0018] Based on these findings, one side of the target material V was coated with a low-melting resin (for example, "polypropylene M"), and the result of trimming while avoiding contact between the blade and the low-melting resin, which would cause the resin to soften and melt, is shown in Figure 1(c). As shown in Figure 1(c), it was confirmed that the softening and melting of the low-melting resin caused by contact (friction) between the blade and the low-melting resin was avoided, and the penetration of the low-melting resin into the shear surface was significantly suppressed.

[0019] First Embodiment The present invention will be described below through the embodiments of the present invention. The configuration of a side trimming device 20 according to a first embodiment of the present invention will be described with reference to Figs. 2 and 3. Fig. 2 shows a schematic side view of the side trimming device 20. Fig. 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 described above. The metal strip F is transported along the metal strip transport direction W by a transport roll or the like. Note that, although the first embodiment describes a method of using the metal strip F as the target material V to be trimmed, the target material V to be trimmed may be a sheet material such as an aluminum plate or a mild steel plate that is a metal plate and is widely used as a container material.

[0020] As shown in FIG. 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 rotary blades that rotate when trimming the metal strip F. The upper blade 11 and the lower blade 12 are fixed in position in the vertical direction when trimming the metal strip F. As shown in FIG. 2, which is a schematic side view, the upper blade 11 and the lower blade 12 have a region where they partially overlap in the vertical direction. The overlapping region of the upper blade 11 and the lower blade 12 starts at position X along the metal strip conveying direction W, and reaches a maximum overlap in the vertical direction at position Y.

[0021] The metal strip F is transported along the metal strip transport direction W and is introduced into an upper blade 11 and a lower blade 12 that are fixed in position in the vertical direction and have an overlapping area. Then, trimming is performed by the upper blade 11 and the lower blade 12.

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

[0023] 3(a) and 3(b), when trimming is performed by 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 a portion that occupies a range of, for example, about 5 to 15 mm from the edge end of the metal strip F toward the inside in the width direction A of the metal strip F.

[0024] 3, the low melting point resin R is coated on the upper surface of the metal strip F, and then trimming is performed. As described above, the low melting point resin R (resin having a melting point of 200° C. or less) softens and melts due to frictional heat caused by contact with the blades during trimming. For this reason, this embodiment is characterized by the positional relationship between the surface (upper or lower surface) of the metal strip F coated with the low melting point resin R and the upper blade 11 and lower blade 12, which will be described in detail below.

[0025] 3(a), at the start of trimming, first, the metal strip F is carried into the side trimming device 20 so that the upper surface of the metal strip F is coated with low-melting point resin R. Then, in the width direction A of the metal strip F, a lower blade 12 is placed below the metal strip side portion F2 to be trimmed. Also, an upper blade 11 is placed 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, above the metal main body portion F1 that will be used as a product after trimming.

[0026] 3(b), which shows the end of trimming, the lower blade 12 advances vertically relative to the metal strip F, thereby trimming the metal strip F and dividing it into a metal main body portion F1 and a metal strip side portion F2. That is, although the upper blade 11 is fixed in position in the vertical direction, the upper cutting edge of the lower blade 12 advances relatively to the metal strip F as the metal strip F is transported in the metal strip transport direction W.

[0027] Here, the metal main body portion F1 is maintained on a conveyor belt or other such transport line (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 to be trimmed is in contact only with the lower blade 12 during trimming, so it moves upward simultaneously with trimming, and is completely cut off when trimming is completed as shown in Fig. 3(b).

[0028] As described above, low-melting-point resin (resin with a melting point of 200° C. or less) is affected by frictional heat due to contact with the blade and softens and melts, but in this embodiment shown in FIG. 3, contact between the lower blade 12, which advances relatively in the vertical direction, and the low-melting-point resin R is kept avoided. In other words, by arranging the blade (lower blade 12 in this embodiment), which advances relatively in the vertical direction during trimming, on a surface (lower surface) different from the surface (upper surface) coated with the low-melting-point resin R, it is possible to suppress softening and melting of the low-melting-point resin R. Furthermore, it is possible to suppress the penetration of the softened and melted resin into the sheared surface, and also to suppress adhesion and accumulation of the resin on the blade.

[0029] That is, when trimming the metal strip F, first, a first blade (upper blade 11) is placed on one surface coated with the low melting point resin R, adjacent to the metal strip side portion F2 and at a position inside in the width direction A of the metal strip F, and a second blade (lower blade 12) is placed on the other surface of the metal strip F at the metal strip side portion F2 that is outside the first blade (upper blade 11) in the width direction A of the metal strip F. Thereafter, while rotating the first blade (upper blade 11) and the second blade (lower blade 12), the second blade (lower blade 12) is advanced relatively in the vertical direction into the metal strip F to trim the metal strip side portion F2 of the metal strip F, thereby suppressing adhesion and accumulation of resin on the blades.

[0030] Next, the positional relationship between the metal main body portion F1, the metal band side portion F2, and the pair of blades (upper blade 11 and lower blade 12) in the state between the start point of trimming shown in FIG. 3(a) and the end point of trimming shown in FIG. 3(b) (hereinafter referred to as the "intermediate point") will be described in detail using FIG. 4(a).

[0031] As shown in Fig. 4(a), it can be seen that the lower blade 12 arranged on the other surface (lower surface) of the metal strip F that is not coated with the low melting point resin R suppresses adhesion and accumulation of resin at the midpoint of trimming. In addition, by performing trimming, burrs were generated on the one surface (upper surface) coated with the low melting point resin R, and the intrusion of the low melting point resin R into the sheared surface was suppressed.

[0032] Next, trimming of a metal strip F coated with resin on both sides will be explained with reference to Figures 4(b) and 4(c), which show the state at the middle of trimming. Figure 4(b) shows the state where the resin is trimmed without penetrating the sheared surface, and Figure 4(c) shows the state where the resin has penetrated the sheared surface.

[0033] FIG. 4(b) shows a state where a metal strip F, the lower surface of which is coated with a resin T (hereinafter also referred to as "high melting point resin") having a melting point exceeding 200°C, and the upper surface of which is coated with a low melting point resin R, is trimmed using a pair of blades (upper blade 11 and lower blade 12). Also in FIG. 4(b), the lower blade 12, which relatively advances in the vertical direction, and the low melting point resin R are prevented from contacting each other. This makes it possible to suppress the softening and dissolution of the low melting point resin R, and to suppress the intrusion of the softened and dissolved resin into the sheared surface, and also to suppress the adhesion and accumulation of the resin on the blades. Furthermore, by performing the trimming, burrs are generated on one surface (upper surface) coated with the low melting point resin R, and the intrusion of the low melting point resin R into the sheared surface is suppressed.

[0034] On the other hand, Fig. 4(c) shows a state in which a metal strip F, the lower surface of which is coated with a low melting point resin R and the upper surface of which is coated with a high melting point resin T, is trimmed using a pair of blades (upper blade 11 and lower blade 12). As shown in Fig. 4(c), during trimming, the lower blade 12, which advances 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 sheared surface, inducing the adhesion and accumulation of the resin on the surface of the blades.

[0035] 4(b) and 4(c), even when trimming a metal strip F coated with resin on both sides, adhesion and accumulation of resin on the blades can be suppressed by the same method as described above with reference to Fig. 3 and 4(a). That is, when trimming the metal strip F, first, a first blade (upper blade 11) is placed on one side coated with low melting point resin R, adjacent to the metal strip side portion F2 and on the inside in the width direction A of the metal strip F, and a second blade (lower blade 12) is placed on the other side of the metal strip F, on the metal strip side portion F2 that is on the outside of the first blade (upper blade 11) in the width direction A of the metal strip F. Thereafter, while rotating the first blade (upper blade 11) and the second blade (lower blade 12), the second blade (lower blade 12) is advanced relatively in the vertical direction toward the metal strip F to trim the metal strip side portion F2 of the metal strip F, thereby preventing the adhesion and accumulation of resin on the blades.

[0036] Here, the configuration of the side trimming device 20 in Figure 3 has been described as a case in which, during trimming, a first blade (upper blade 11) is placed on one surface (upper surface) coated with low-melting point resin R, adjacent to the metal strip side portion F2 and at a position inside in the width direction A of the metal strip F, and a second blade (lower blade 12) is placed on the other surface (lower surface) of the metal strip F, at the metal strip side portion F2 which is outside the first blade (upper blade 11) in the width direction A of the metal strip F.

[0037] The above arrangement during trimming avoids contact between the lower blade 12, which advances relatively in the vertical direction, and the low-melting point resin R, suppressing softening and dissolution of the low-melting point resin R, suppressing penetration of the softened and dissolved resin into the sheared surface, and suppressing adhesion and accumulation of the resin on the blade. In other words, as long as contact between the blade, which advances relatively in the vertical direction, and the low-melting point resin R is avoided, the same effect can be obtained.

[0038] Therefore, when the metal strip F is coated on its underside with low melting point resin R and transported into the side trimming device 20, the same effect can be obtained by adjusting the positions of the pair of blades (upper blade 11 and lower blade 12) relative to the metal strip F.

[0039] Specifically, first, a first blade (lower blade 12) is placed on one surface (lower surface) coated with the low melting point resin R, adjacent to the metal strip side portion F2 and at a position inside in the width direction A of the metal strip F, and a second blade (upper blade 11) is placed on the other surface (upper surface) of the metal strip F at the metal strip side portion F2 that is outside the first blade (lower blade 12) in the width direction A of the metal strip F. Thereafter, while rotating the first blade (lower blade 12) and the second blade (upper blade 11), the second blade (upper blade 11) is advanced relatively in the vertical direction into the metal strip F to trim the metal strip side portion F2 of the metal strip F, thereby suppressing adhesion and accumulation of resin on the blades.

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

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

[0042] Therefore, regardless of whether a metal strip F having a low melting point resin R coated on its upper surface or a metal strip F having a low melting point resin R coated on its lower surface is brought into the side trimming device 20, the surface coated with the low melting point resin R can be detected by a separately provided resin surface detector, and 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 based on the detection result.

[0043] In this case, more specifically, a mechanism is provided to adjust the axial length of upper and lower spindle motors (not shown) that hold the upper blade 11 and the lower blade 12, and by adjusting the axial length, 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.

[0044] Here, the upper blade 11 and the lower blade 12 in the first embodiment are preferably trimmer blades capable of trimming a metal strip, which is the workpiece, and are preferably a pair of rotary blades arranged opposite each other in the vertical direction.

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

[0046] <Second embodiment> Next, the configuration of a side trimming device 10 according to a second embodiment of the present invention will be described with reference to Fig. 5. Fig. 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 above.

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

[0048] Fig. 5(a) shows a state immediately before trimming the sheet material S in a side trimming device 10 that trims a sheet material S coated with a low melting point resin R, with a pair of blades (upper blade 1 and lower blade 2) positioned relative to the sheet material S. Fig. 5(b) shows a state immediately after the sheet material S has been trimmed by the pair of blades (upper blade 1 and lower blade 2) in the side trimming device 10.

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

[0050] 5, the low melting point resin R is applied to the upper surface of the sheet material S, and then the sheet material S is trimmed. As described above, the low melting point resin R (a resin having a melting point of 200° C. or less) is softened and melted by frictional heat generated by contact with the blade during trimming. Therefore, this embodiment is characterized by the positional relationship between the surface (upper or lower surface) of the sheet material S that is covered with the low melting point resin R, and the upper blade 1 and the lower blade 2, which will be described in detail below.

[0051] 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 coated with low melting point resin R. Then, in the width direction A of the sheet material S, a lower blade 2 is placed below the sheet side portion S2 to be trimmed. Also, an upper blade 1 is placed above the sheet main body portion S1 that will be used as a product after trimming, 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 FIG. 5(b), the pair of blades approaches each other so that the distance between the upper blade 1 and the lower blade 2 in the vertical direction becomes smaller, whereby the sheet material S is trimmed and divided into a sheet main body portion S1 and a sheet side portion S2.

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

[0054] As described above, low-melting-point resin (resin with a melting point of 200° C. or less) is affected by frictional heat due to contact with the blade and softens and melts, but in this embodiment shown in FIG. 5, contact between the moving lower blade 2 and the low-melting-point resin R is kept avoided. In other words, by arranging the moving blade (lower blade 2 in this embodiment) on a different surface (lower surface) from the surface (upper surface) coated with the low-melting-point resin R during trimming, it is possible to suppress softening and melting of the low-melting-point resin R. This in turn suppresses the penetration of the softened and melted resin into the sheared surface, and also suppresses adhesion and accumulation of the resin on the blade.

[0055] That is, when trimming the sheet material S, first, a first blade (upper blade 1) is placed on one surface coated with the low melting point resin R, adjacent to the sheet side portion S2 and on the inside in the width direction A of the sheet material S, and a second blade (lower blade 2) is placed on the other surface of the sheet material S, on the sheet side portion S2 that is on the outside of the first blade (upper blade 1) in the width direction A of the sheet material S. After that, the second blade (lower blade 2) is moved in the direction in which the first blade (upper blade 1) is positioned to trim the sheet side portion S2 of the sheet material S, thereby preventing the resin from adhering to and accumulating on the blade.

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

[0057] As shown in Fig. 6(a), it can be confirmed that the adhesion and accumulation of resin was suppressed after trimming on the lower blade 2 arranged on the other surface (lower surface) of the sheet material S that is not coated with the low melting point resin R. In addition, by performing trimming, burrs were generated on the one surface (upper surface) coated with the low melting point resin R, and the low melting point resin R was prevented from entering the shear surface.

[0058] Next, the case where a sheet material S coated with resin on both sides is trimmed will be explained with reference to Fig. 6(b) and Fig. 6(c). Fig. 6(b) shows the state where the resin has entered the sheared surface after trimming, while Fig. 6(c) shows the state where the resin has entered the sheared surface.

[0059] FIG. 6(b) shows a state where a sheet material S, the lower surface of which is covered with resin T (hereinafter also referred to as "high melting point resin") having a melting point exceeding 200°C, and the upper surface of which is covered with low melting point resin R, is trimmed using a pair of blades (upper blade 1 and lower blade 2). Also in FIG. 6(b), contact between the moving lower blade 2 and the low melting point resin R is avoided. This makes it possible to suppress softening and dissolution of the low melting point resin R, and to suppress the softened and dissolved resin from penetrating the sheared surface, and also to suppress adhesion and accumulation of the resin on the blades. Furthermore, by performing the trimming, burrs are generated on one surface (upper surface) covered with the low melting point resin R, and the low melting point resin R is prevented from penetrating the sheared surface.

[0060] On the other hand, Fig. 6(c) shows a state in which a sheet material S, the lower surface of which is coated with low melting point resin R and the upper surface of which is coated with high melting point resin T, is trimmed using a pair of blades (upper blade 1 and lower blade 2). As shown in Fig. 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 sheared surface, inducing the adhesion and accumulation of the 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 by the same method as that described above using Figures 5 and 6(a). That is, when trimming the sheet material S, first, a first blade (upper blade 1) is placed on one side coated with the low melting point resin R, adjacent to the sheet side portion S2 and at a position inside the width direction A of the sheet material S, and a second blade (lower blade 2) is placed on the other side of the sheet material S at the sheet side portion S2 that is outside the width direction A of the sheet material S from the first blade (upper blade 1). Then, the second blade (lower blade 2) is moved in the direction where the first blade (upper blade 1) is located to trim the sheet side portion S2 of the sheet material S, thereby suppressing the adhesion and accumulation of resin on the blade.

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

[0063] Moreover, by adopting the above-mentioned arrangement during trimming, contact between the moving lower blade 2 and the low melting point resin R is avoided, softening and dissolution of the low melting point resin R can be suppressed, the softened and dissolved resin is prevented from penetrating the sheared surface, and adhesion and accumulation of the resin on the blade can be suppressed. 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 coated on the underside thereof, the same 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, a first blade (lower blade 2) is placed on one surface (lower surface) coated with low melting point resin R, adjacent to the sheet side portion S2 and on the inside in the width direction A of the sheet material S, and a second blade (upper blade 1) is placed on the other surface (upper surface) of the sheet material S, on the sheet side portion S2 that is outside the first blade (lower blade 2) in the width direction A of the sheet material S. After that, the second blade (upper blade 1) is moved in the direction in which the first blade (lower blade 2) is positioned to trim the sheet side portion S2 of the sheet material S, thereby preventing the resin from adhering to and accumulating on the blade.

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

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

[0068] Therefore, regardless of whether a sheet material S having a low melting point resin R coated on its upper surface or a sheet material S having a low melting point resin R coated on its lower surface is inserted into the side trimming device 10, the surface coated with the low melting point resin R can be detected by a separately provided resin surface detector, and the positions of the upper blade 1 and the lower blade 2 in the width direction A of the sheet material S can be adjusted based on the detection result.

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

[0070] Here, as the upper blade 1 and the lower blade 2 in the second embodiment, it is preferable to apply a shear blade that enables trimming of a sheet material that is the workpiece.

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

[0072] Here, the low melting point resin R (resin having 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, and the like can be used. The polyester resin may be copolymerized with various dicarboxylic acid components and glycol components within a range that does not impair processability, corrosion resistance, and the like. Examples of the dicarboxylic acid component include aromatic dicarboxylic acids such as isophthalic acid, naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, 5-sodiumsulfoisophthalic 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. In addition, the polyolefin resin may contain a layer using a polypropylene-based resin or even a propylene-ethylene block copolymer to improve processability. In addition, in order to improve adhesion to the metal plate, a mixed resin containing adhesive polypropylene and adhesive polyethylene as the main component resins may be used in the lower layer.

[0073] Next, the sheet material S in the second embodiment will be described. As the sheet material S, a metal plate, such as an aluminum plate or a mild steel plate, which is widely used as a material for containers, can be used. Furthermore, as for the surface treatment, a steel plate such as tinplate or tin-free steel can be used. As for tinplate, a plating amount of 0.5 g / m 2 More than 15g / m 2 The following range is preferable: Tin-free steel has a coating weight of 50 mg / m 2 More than 200g / m 2 A metal chrome layer within the following range and a metal chrome layer equivalent coating weight of 3mg / m 2 More than 30g / m 2It is preferable that the steel sheet has a chromium oxide layer on the surface thereof within the following range: The type of steel sheet is not particularly limited as long as it can be formed into a desired shape. EXAMPLES

[0074] Hereinafter, as an example, a result of trimming a target material coated with a low melting point resin using the side trimming device 20 in the first embodiment will be described.

[0075] The target material was a 0.22 mm thick TFS (tin free steel, metal Cr layer: 120 mg / m 2 Cr oxide layer: 10mg / m2 in terms of metallic Cr 2 , temper: T3CA) was used. As shown in Table 1 as examples of the present invention and comparative examples, both sides or one side (upper or lower side) 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 stretched film-like resin was thermocompression-bonded to the target material by a lamination roll, and one second after thermocompression bonding, the target material was cooled with water to prepare a sample in which both sides or one side of the target material was coated with resin.

[0076] Thereafter, the prepared sample was trimmed using a side trimming device 20 shown in Fig. 3, and the state of adhesion and deposition of the resin on the blade was examined. The examination results are shown in Table 1.

[0077] [Table 1]

[0078] In the "Resin Coating Structure" section of Table 1, "PP" refers to polypropylene. "PE-dispersed PP" refers to polyethylene-dispersed polypropylene. Additionally, "PET-isophthalic acid copolymerized" refers to polyethylene terephthalate-copolymerized with isophthalic acid. Additionally, "PP" and "PE-dispersed PP" are low-melting-point resins (resins with a melting point of 200°C or less). "PET-isophthalic acid copolymerized" is a high-melting-point resin (resin with a melting point of over 200°C).

[0079] In addition, in the column of "Resin adhesion or deposition on the blade" in Table 1, if no resin adhesion or deposition was found on the surface of the blade after trimming the sample, it was evaluated as "○ (good)", and if resin adhesion or deposition on the surface of the blade was found, it was evaluated as "× (bad)".

[0080] In the present invention examples 1 to 3, the upper surface was coated with a low melting point resin, "PE-dispersed PP" or "PP". Based on this, an upper blade was placed on the upper surface of the target material, adjacent to the side of the metal strip to be trimmed, and on the inner side of the width of the target material. Furthermore, a lower blade was placed on the side of the metal strip on the lower surface of the target material, which relatively advances into the target material in the vertical direction, and trimming was performed. As a result, contact between the lower blade, which relatively advances into the target material in the vertical direction, and the low melting point resin was avoided, suppressing softening and dissolution of the low melting point resin, and no adhesion or accumulation of resin was observed on the blade, resulting in good results.

[0081] In Example 4 of the present invention, the lower surface was coated with "PP", a low melting point resin. Based on this, a lower blade was placed on the lower surface of the target material, adjacent to the side of the metal strip to be trimmed, and on the inner side of the width of the target material. Furthermore, an upper blade that advances relatively to the target material in the vertical direction was placed on the side of the metal strip on the upper surface of the target material, and trimming was performed. As a result, contact between the upper blade that advances relatively to the target material in the vertical direction and the low melting point resin was avoided, and softening and dissolution of the low melting point resin was suppressed, and no adhesion or accumulation of resin was observed on the blade, resulting in good results.

[0082] In Comparative Examples 1 to 3, the upper surface was coated with a low melting point resin, "PE-dispersed PP" or "PP". A lower blade was placed on the lower surface of the target material adjacent to the side of the metal strip to be trimmed and on the inner side of the width of the target material. Furthermore, an upper blade was placed on the side of the metal strip to relatively advance against the target material in the vertical direction on the upper surface of the target material, and trimming was performed. As a result, contact occurred between the upper blade, which relatively advances against the target material in the vertical direction, and the low melting point resin, causing softening and melting of the low melting point resin, and the low melting point resin penetrated into the sheared surface, causing adhesion and accumulation on the surface of the blade.

[0083] As described above, by using the side trimming method and side trimming device according to the present invention, even when trimming a target material coated with a low melting point resin, it is possible to prevent the adhesion and accumulation of resin on the blade used for trimming, prevent deterioration of the trimming performance of the blade, and extend the life of the blade, thereby maintaining the productivity of the processing line. [Explanation of symbols]

[0084] 1, 11 Upper blade 2, 12 Lower blade 10, 20 Side trimming device A (of target material V) width direction E Burr F Metal strip F1 Metal body F2 Metal strip side M Polypropylene N Polyethylene terephthalate R Low melting point resin S Sheet material S1 Seat body S2 Seat side part T High melting point resin W Metal strip conveying direction V Target material X,Y position

Claims

1. 1. A side trimming method for trimming a side portion of a metal strip, the side portion being coated with a resin having a melting point of 200° C. or less, while conveying the metal strip, the side portion being trimmed, the method comprising the steps of: a first blade which is a rotary blade is disposed on the one surface adjacent to the side portion of the metal strip and on the inside in the width direction of the metal strip, and a second blade which is a rotary blade is disposed on the other surface of the metal strip on the side portion of the metal strip which is on the outside of the first blade in the width direction of the metal strip, A side trimming method comprising rotating the first blade and the second blade while relatively inserting the second blade in a vertical direction toward the metal strip to trim a side portion of the metal strip.

2. 1. A side trimming method for trimming a side portion of a metal strip while transporting the metal strip, comprising the steps of: Detecting the surface of the metal strip that is coated with a resin having a melting point of 200° C. or less; a first blade, which is a rotary blade, is disposed adjacent to the side portion of the metal strip on one surface where the resin is detected and at a position inside in the width direction of the metal strip, and a second blade, which is a rotary blade, is disposed on the other surface of the metal strip on the side portion of the metal strip that is outside the first blade in the width direction of the metal strip; A side trimming method comprising rotating the first blade and the second blade while relatively inserting the second blade in a vertical direction toward the metal strip to trim a side portion of the metal strip.

3. 1. A side trimming device for trimming a side portion of a metal strip, the side portion being coated with a resin having a melting point of 200° C. or less, while conveying the metal strip, the side trimming device comprising: a first blade of a rotary blade that is adjacent to the metal strip side portion on the one surface and is located at an inner position in the width direction of the metal strip; a second blade which is a rotary blade arranged on the other surface of the metal strip at a side portion of the metal strip that is on the outer side of the first blade in the width direction of the metal strip, and which rotates together with the rotation of the first blade while advancing relatively into the metal strip in the vertical direction to trim the side portion of the metal strip; A side trimming device having

4. 1. A side trimming device for trimming a side portion of a metal strip while transporting the metal strip, comprising: a resin surface detector for detecting a surface of the metal strip that is coated with a resin having a melting point of 200° C. or less; a first blade of a rotary blade that is adjacent to the metal strip side portion on one surface on which the resin is detected by the resin surface detector and is disposed at an inner position in the width direction of the metal strip; a second blade which is a rotary blade arranged on the other surface of the metal strip at a side portion of the metal strip that is on the outer side of the first blade in the width direction of the metal strip, and which rotates together with the rotation of the first blade while advancing relatively into the metal strip in the vertical direction to trim the side portion of the metal strip; A side trimming device having

5. 1. A side trimming method for trimming a sheet side portion of a sheet material having one surface coated with a resin having a melting point of 200° C. or less, comprising the steps of: A first blade is disposed on the one surface adjacent to the sheet side portion and on the inner side in the width direction of the sheet material, and a second blade is disposed on the other surface of the sheet material on the sheet side portion that is on the outer side of the first blade in the width direction of the sheet material, A side trimming method comprising: moving the second blade in a vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material.

6. A side trimming method for trimming a sheet side portion of a sheet material, comprising the steps of: Detecting the surface of the sheet material that is coated with a resin having a melting point of 200° C. or less; a first blade is disposed adjacent to the sheet side portion on one surface where the resin is detected and located on the inner side in the width direction of the sheet material, and a second blade is disposed on the other surface of the sheet material on the sheet side portion that is on the outer side of the first blade in the width direction of the sheet material; A side trimming method comprising: moving the second blade in a vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material.

7. A side trimming device for trimming a sheet side portion of a sheet material having one surface coated with a resin having a melting point of 200° C. or less, comprising: a first blade disposed adjacent to the sheet side portion on the one surface and at an inner position in a width direction of the sheet material; a second blade that is disposed on the other surface of the sheet material at a sheet side portion that is on the outer side of the sheet material in the width direction of the sheet material than the first blade and moves in the vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material; A side trimming device having

8. A side trimming device for trimming a sheet side portion of a sheet material, comprising: a resin surface detector for detecting a surface of the sheet material that is coated with a resin having a melting point of 200° C. or less; a first blade disposed adjacent to the sheet side portion on one surface on which the resin is detected by the resin surface detector and at an inner position in a width direction of the sheet material; a second blade that is disposed on the other surface of the sheet material at a sheet side portion that is on the outer side of the sheet material in the width direction of the sheet material than the first blade and moves in the vertical direction toward the position of the first blade to trim the sheet side portion of the sheet material; A side trimming device having

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