Method for manufacturing a sheet product with eyelets

Abstract

To provide a method for manufacturing a sheet product having grommets. [Solution] The method includes providing a sheet having one or more perforations, positioning the grommet such that the grommet contacts the sheet around the one or more perforations, and ultrasonically fusing the grommet to the sheet under a predetermined pressure. In one embodiment, ultrasonically fusing the grommet to the sheet under a predetermined pressure may include applying ultrasonic waves to the grommet and sheet for a first time while applying a predetermined pressure to the grommet and sheet to bond the grommet to the sheet, ceasing the ultrasonic waves and continuing to apply a predetermined pressure to the grommet and sheet for a second time.

Description

[Technical field]

[0001] The present invention relates to a method for producing a sheet product having grommets and to the grommets. [Background technology]

[0002] In recent years, synthetic resin grommets have been increasingly used instead of aluminum grommets due to the ease of disposal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4716849 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional sheet products equipped with synthetic resin grommets had problems with the strength of the grommets because, when the area around the grommets was pulled with great force, the grommets would come apart from the sheet or the grommets themselves would become deformed.

[0005] An object of the present invention is to provide a sheet product having synthetic resin grommets with sufficient strength. [Means for solving the problem]

[0006] In one aspect of the invention, a method of the invention is a method of producing a sheet product having grommets, the method including providing a sheet having one or more perforations, positioning the grommets such that the grommets contact the sheet around the one or more perforations, and ultrasonically fusing the grommets to the sheet under a predetermined pressure.

[0007] In one embodiment of the present invention, fusing the eyelet to the sheet using the ultrasonic waves under the predetermined pressure may include bonding the eyelet to the sheet by oscillating the ultrasonic waves to the eyelet and the sheet for a first time while applying the predetermined pressure to the eyelet and the sheet, and ceasing the oscillation of the ultrasonic waves and continuing to apply the predetermined pressure to the eyelet and the sheet for a second time.

[0008] In one embodiment of the present invention, the first period of time may be between about 0.15 seconds and about 0.4 seconds.

[0009] In one embodiment of the present invention, the first period of time may be between about 0.2 seconds and about 0.3 seconds.

[0010] In one embodiment of the present invention, the second period of time may be between about 0.2 seconds and about 0.3 seconds.

[0011] In one embodiment of the present invention, the second period of time may be between about 0.23 seconds and about 0.28 seconds.

[0012] In one embodiment of the present invention, the eyelet may have a circular ring shape, an outer diameter of the eyelet may be about 28 mm to about 40 mm, and an inner diameter of the eyelet may be about 11 mm to about 20 mm.

[0013] In one embodiment of the present invention, the eyelet is composed of a first eyelet member and a second eyelet member, and positioning the eyelet so that the eyelet contacts the sheet around the one or more perforations includes sandwiching the sheet around the one or more perforations between the first eyelet member and the second eyelet member, and fusing the eyelet to the sheet using the ultrasonic wave under the predetermined pressure may include oscillating the ultrasonic wave to the first eyelet member, the second eyelet member, and the sheet under the predetermined pressure with the sheet around the one or more perforations sandwiched between the first eyelet member and the second eyelet member.

[0014] In one embodiment of the present invention, the second eyelet member has one or more protrusions, and the first eyelet member has one or more recesses corresponding to the one or more protrusions, and fusing the eyelet to the sheet using the ultrasonic waves under the predetermined pressure may include oscillating the ultrasonic waves to the one or more protrusions, the one or more recesses, and the sheet under the predetermined pressure, so that the sheet around the one or more protrusions and the one or more recesses becomes integrated with the one or more protrusions and the one or more recesses, and adheres the eyelet to the sheet.

[0015] In one embodiment of the present invention, the eyelet may be made of a synthetic resin, and the sheet may be made of a synthetic resin.

[0016] In one embodiment of the present invention, in a JIS L1096 trapezoid method strength test, the strength of the grommets in the sheet product may be approximately 100% or more of the strength of a sheet without the grommets.

[0017] In one aspect of the present invention, the eyelet of the present invention is an eyelet for reinforcing one or more perforations provided in a sheet of a sheet product, the eyelet being composed of a first eyelet member and a second eyelet member, the first eyelet member and the second eyelet member being fused to the sheet in a state in which they are arranged to sandwich the sheet of the sheet product around the one or more perforations, and in a JIS L1096 trapezoid method strength test, the strength of the eyelet in the sheet product is approximately 100% or more of the strength of a sheet without the eyelet.

[0018] In one embodiment of the present invention, in the strength test, the strength of the grommets in the sheet product may be about 110% to about 200% of the strength of a sheet without the grommets.

[0019] In one embodiment of the present invention, the eyelet may have a circular ring shape, an outer diameter of the eyelet may be about 28 mm to about 40 mm, and an inner diameter of the eyelet may be about 11 mm to about 20 mm.

[0020] In one embodiment of the present invention, the eyelet may be made of a synthetic resin, and the sheet may be made of a synthetic resin. Effect of the Invention

[0021] According to the present invention, it is possible to provide a sheet product having sufficient eyelet strength by fusing the eyelets to the sheet. [Brief description of the drawings]

[0022] [Figure 1] 1 is an exploded perspective view showing an example of the configuration of a sheet 100 and an eyelet 200 in a sheet product 10 around the eyelet. FIG. [Diagram 2] An example of the configuration of an apparatus 300 for fusing the eyelets 200 to the sheet 100 is shown. [Diagram 3] 3 shows an embodiment of an apparatus 300. [Figure 4] An example of a method for producing a sheet product 10 having grommets 200 fused to a sheet 100 is shown. [Figure 5A] The test specimen used in the JIS L1096 trapezoid method strength test is shown. [Figure 5B] This shows the state in which a test piece used in the trapezoid method strength test of JIS L1096 is held by a holding member. [Figure 5C] This shows the state in which a test piece used in the trapezoid method strength test of JIS L1096 is pulled by a gripping member. [Figure 6A] The test results of Examples 1 to 6 based on the JIS L1096 trapezoid method strength test are shown. [Figure 6B] The test results of Examples 7 to 11 based on the strength test of the trapezoid method of JIS L1096 are shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The applicant proposes to manufacture a sheet product with high eyelet strength by fusing the eyelet to the sheet using ultrasonic waves under a certain pressure. For example, if the ultrasonic oscillation time is too long, the eyelet and the sheet may be burned. Conversely, if the ultrasonic oscillation time is too short, the eyelet and the sheet may not be sufficiently fused. Therefore, the applicant has realized the manufacture of a sheet product with high eyelet strength by devising a method and conditions for fusing the eyelet to the sheet.

[0024] The terms used in this specification are defined below.

[0025] "Sheet product" refers to a product in which grommets are provided on the sheet.

[0026] The "strength of a grommet" in a sheet product refers to the maximum tensile force recorded over time in a trapezoid method strength test according to JIS L1096 by continuously pulling on the area around the grommet of a sheet product having a grommet.

[0027] "Sheet without grommets" refers to a sheet portion of a sheet product that has grommets and is 10 cm or more away from the grommets, or a sheet identical to that sheet but that does not have grommets.

[0028] "Strength of sheet without grommets" refers to the maximum tensile force recorded over time when a sheet without grommets is continuously pulled in a trapezoid method strength test according to JIS L1096.

[0029] The term "about" refers to ±10% of the value immediately preceding it, unless expressly stated otherwise.

[0030] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0031] FIG. 1 is an exploded perspective view showing an example of the configuration of a sheet 100 and an eyelet 200 in a sheet product 10, and the surrounding area of ​​the eyelet.

[0032] The sheet 100 has one or more perforations 110. A long object such as a rope can be passed through the one or more perforations 110 of the sheet 100.

[0033] The eyelet 200 is positioned so that the eyelet 200 contacts the sheet 100 around one or more perforations 110. In the embodiment shown in Fig. 1, the eyelet 200 is composed of a first eyelet member 210 and a second eyelet member 220. In the embodiment shown in Fig. 1, the first eyelet member 210 and the second eyelet member 220 are positioned so as to sandwich the sheet 100 in the sheet product 10 around the one or more perforations 110.

[0034] With the first eyelet member 210 and the second eyelet member 220 arranged to sandwich the sheet 100 around one or more perforations 110, a predetermined pressure is applied to the sheet 100 and the eyelet 200, and ultrasonic waves are applied under the predetermined pressure. This causes a part of the eyelet 200 to fuse with a part of the sheet 100, so that the eyelet 200 can be fused to the sheet 100.

[0035] 1, the second eyelet member 220 includes one or more protrusions 221, and the first eyelet member 210 includes one or more recesses (not shown) corresponding to the one or more protrusions of the second eyelet member 220. With this, by oscillating ultrasonic waves to the one or more protrusions 221 of the second eyelet member 220, the one or more recesses of the first eyelet member 210, and the sheet 100 under a predetermined pressure, the sheet 100 around the one or more protrusions 221 of the second eyelet member 220 and the one or more recesses of the first eyelet member 210 becomes integrated with the one or more protrusions 221 of the second eyelet member 220 and the one or more recesses of the first eyelet member 210, and the eyelet 200 can be bonded to the sheet 100.

[0036] The thickness of the sheet 100 may be about 0.08 mm to about 0.4 mm. The thickness of the sheet 100 may be, for example, about 0.4 mm to about 0.3 mm, about 0.3 mm to about 0.2 mm, or about 0.2 mm to 0.1 mm, specifically, any of 0.35 mm, 0.22 mm, and 0.15 mm. The sheet 100 may be made of, for example, a synthetic resin, but the present invention is not limited thereto. The sheet 100 may be made of, for example, polyethylene, polypropylene, or polyvinyl chloride (PVC).

[0037] In the embodiment shown in Fig. 1, the eyelet 200 has a circular ring shape. In this case, the outer diameter of the eyelet 200 may be about 28 mm to about 40 mm, and the inner diameter of the eyelet 200 may be about 11 mm to about 20 mm. The eyelet 200 may be made of, for example, a synthetic resin, but the present invention is not limited thereto. The eyelet 200 may be made of, for example, polyethylene, polypropylene, or polycarbonate.

[0038] 1, for convenience, one perforation of the one or more perforations 110 is shown on the sheet 100. Also, in the embodiment shown in FIG. 1, for convenience, one grommet 200 is shown adjacent to the sheet 100, but the invention is not limited thereto. The number of grommets 200 on the sheet 100 may be any number equal to or greater than one.

[0039] In the embodiment shown in Fig. 1, a combination of the second eyelet member 220 having one or more protrusions 221 and the first eyelet member 210 having one or more recesses corresponding to the one or more protrusions of the second eyelet member 220 has been described, but the present invention is not limited thereto. For example, the second eyelet member 220 may have one or more protrusions 221, and the first eyelet member 210 may have one or more protrusions corresponding to the one or more protrusions of the second eyelet member 220. Alternatively, the second eyelet member 220 may have one or more protrusions 221, and the first eyelet member 210 may have a flat surface. Alternatively, the second eyelet member 220 may have a flat surface, and the first eyelet member 210 may have one or more protrusions.

[0040] 1, an example has been described in which the second eyelet member 220 includes one or more protrusions 221 that are independent of each other, but the present invention is not limited to this. For example, the first eyelet member 210 and / or the second eyelet member 220 may include one or more protrusions that extend continuously in the circumferential direction.

[0041] 1, the pressure and ultrasonic waves are applied from the side of the first eyelet member 210, but the present invention is not limited to this. The pressure and ultrasonic waves may be applied from any direction as long as they can be applied to the sheet 100 and the eyelet 200.

[0042] 1, an example in which the eyelet 200 is composed of the first eyelet member 210 and the second eyelet member 220 has been described, but the present invention is not limited to this. As long as the eyelet 200 can be fused to the sheet 100, the eyelet 200 may be configured to be arranged on both sides of the sheet 100 so as to sandwich the sheet 100 as shown in FIG. 1, or may be configured to be arranged on only one side of the sheet 100.

[0043] In a JIS L1096 trapezoid strength test, the strength of the grommets 200 in the sheet product 10 is about 100% or more, preferably about 110% or more, and more preferably about 120% or more, of the strength of a portion of the sheet product 10 without the grommets.

[0044] In the sheet product 10 of the present invention in which the sheet 100 is provided with the eyelets 200, the strength of the eyelets 200 in the sheet product 10 in a strength test by the trapezoid method of JIS L1096 can be about 120 N or more, preferably about 140 N or more, and particularly preferably 160 N or more. In a preferred embodiment, in the sheet product 10 in which the sheet 100 having the eyelets 200 is provided with a thickness of about 0.4 mm to about 0.3 mm, the strength of the eyelets 200 in the sheet product 10 in a strength test by the trapezoid method of JIS L1096 can be about 140 N or more, preferably about 160 N or more, and particularly preferably 180 N or more. In another preferred embodiment, in a sheet product 10 having eyelets 200 provided in a sheet 100 having a thickness of about 0.3 mm to about 0.2 mm, the strength of the eyelets 200 in the sheet product 10 in a strength test by the trapezoid method of JIS L1096 may be about 120 N or more, preferably about 140 N or more, and particularly preferably about 160 N or more. In a sheet product 10 of the present invention having eyelets 200 provided in a sheet 100, the strength of the eyelets 200 in the sheet product 10 in a strength test by the trapezoid method of JIS L1096 may be about 250 N or less, or about 220 N or less. The area of ​​the sheet product 10 may be at least 180 cm × at least 180 cm or more.

[0045] FIG. 2 shows an example of the configuration of an apparatus 300 for fusing the eyelets 200 to the sheet 100. As shown in FIG.

[0046] 2, the apparatus 300 includes a processor portion 310, a memory portion 320, an ultrasonic source 330, and a pressure source 340. The apparatus 300 may further include a processing area 350 for receiving the grommets and applying ultrasonic waves and pressure to the grommets.

[0047] The memory unit 320 stores programs required to execute processing, data required to execute the programs, and the like. Here, there is no restriction on how the programs are stored in the memory unit 320. For example, the programs may be pre-installed in the memory unit 320. Alternatively, the programs may be installed in the memory unit 320 by being downloaded via a network such as the Internet, or may be installed in the memory unit 320 via a storage medium such as an optical disk or USB.

[0048] The processor unit 310 controls the overall operation of the device 300. The processor unit 320 reads a program stored in the memory unit 320 and executes the program, so that the device 300 can function to execute desired steps, and the processor unit 320 of the device 300 can operate as a means for achieving a desired function.

[0049] The ultrasonic source 330 is configured to be capable of emitting a desired ultrasonic wave. For example, the ultrasonic source 330 is configured to be capable of emitting a desired ultrasonic wave toward the processing area 350. The frequency of the desired ultrasonic wave is, for example, about 15 kHz to about 30 kHz, about 15 kHz to about 25 kHz, about 15 kHz to about 20 kHz, about 20 kHz to about 30 kHz, about 20 kHz to about 25 kHz, or about 17 kHz to about 23 kHz, but is not limited thereto.

[0050] The pressure source 340 is configured to be capable of applying a desired pressure. For example, the pressure source 340 is configured to be capable of applying a desired pressure toward the processing area 350. The magnitude of the desired pressure is, for example, but not limited to, about 0.6 MPa to about 0.8 MPa, about 0.6 MPa to about 0.7 MPa, or about 0.7 MPa to about 0.8 MPa.

[0051] FIG. 3 shows an embodiment of an apparatus 300 .

[0052] 3, the apparatus 300 further comprises an elongated member 360 for inducing and directing pressure and ultrasound onto a processing area 350 of the apparatus 300. The elongated member 360 is configured to communicate with an ultrasound source 330, such that ultrasound waves from the ultrasound source 330 can be emitted onto the processing area 350 through the elongated member 360. The elongated member 360 is also configured to communicate with a pressure source 340, such that pressure from the pressure source 340 can be applied onto the processing area 350 through the elongated member 360.

[0053] 3, the apparatus 300 may further include a transport means 370 (not shown) for transporting the eyelets 200 (e.g., the first eyelet member 210, the second eyelet member 220) to a processing area 350 of the apparatus 300. The apparatus 300 may further include a switch 380 (not shown) for starting the generation of ultrasonic waves from the ultrasonic source 330 and the application of pressure from the pressure source 340.

[0054] For example, after the eyelets 200 are transported to the processing area 350 by the transport means 370, the user of the apparatus 300 places the sheet 100 on the processing area 350 so that the perforations 110 of the sheet 100 are aligned with the eyelets 200, and presses the switch 380. This enables the pressure source 340 to apply pressure to the eyelets 200 on the processing area 350, and the ultrasonic source 330 to oscillate ultrasonic waves to the eyelets 200 on the processing area 350. In this manner, by applying pressure and ultrasonic waves to the eyelets 200 on the processing area 350, the eyelets 200 can be fused to the sheet 100 around the perforations 110 to obtain the sheet product 10 of the present invention.

[0055] Alternatively, for example, after the second eyelet member 220 is transported to the processing area 350 by the transport means 370, a user of the apparatus 300 places the sheet 100 on the processing area 350 so that the perforations 110 in the sheet 100 are aligned with the second eyelet member 220 and presses the switch 380. As a result, the conveying means 370 conveys the first eyelet member 210 over the perforation 110 in the sheet 100 so that the first eyelet member 210 is aligned with the perforation 110 and the second eyelet member 220 in the sheet 100, and the sheet 100 around the perforation 110 is sandwiched between the first eyelet member 210 and the second eyelet member 220, the pressure source 340 is capable of applying pressure to the first eyelet member 210 and the second eyelet member 220 on the processing area 350, and the ultrasonic source 330 is capable of oscillating ultrasonic waves to the first eyelet member 210 and the second eyelet member 220 on the processing area 350. In this manner, by applying pressure and ultrasound to the first eyelet member 210 and the second eyelet member 220 on the treatment area 350, it is possible to fuse the first eyelet member 210 and the second eyelet member 220 to the sheet 100 around the perforation 110.

[0056] Fig. 4 shows an example of a method for manufacturing a sheet product 10 in which eyelets 200 are fused to a sheet 100. Note that steps S402 and S403 shown in Fig. 4 can be performed using the apparatus 300 shown in Fig. 2. Each step shown in Fig. 4 will be described below.

[0057] Step S401: A sheet 100 with one or more perforations 110 is provided.

[0058] Step S402: The grommet 200 is positioned such that the grommet 200 contacts the sheet 100 around the one or more perforations 110. This is accomplished, for example, by aligning the grommet 200 with the perforations 110 of the sheet 100 on the processing area 350. For example, if the grommet 200 is composed of a first grommet member 210 and a second grommet member 220, step S402 is accomplished by sandwiching the sheet 100 around the one or more perforations 110 between the first grommet member 210 and the second grommet member 220.

[0059] Step S403: Under a predetermined pressure, the eyelet 200 is fused to the sheet 100 using ultrasonic waves. The predetermined pressure may be generated by a pressure source 340. The predetermined pressure may be, for example, about 0.6 MPa to about 0.8 MPa. The ultrasonic waves may be generated by an ultrasonic wave source 330. The frequency of the ultrasonic waves may be, for example, about 15 kHz to about 30 kHz.

[0060] For example, when the eyelet 200 is composed of a first eyelet member 210 and a second eyelet member 220, step S403 is achieved by sandwiching the sheet 100 around one or more perforations 110 between the first eyelet member 210 and the second eyelet member 220 and oscillating ultrasonic waves to the first eyelet member 210, the second eyelet member 220 and the sheet 100 under a predetermined pressure.

[0061] Also, for example, in the case where the second eyelet member 220 has one or more protrusions 221 and the first eyelet member 210 has one or more recesses corresponding to the one or more protrusions 221 of the second eyelet member 220, step S403 includes oscillating ultrasonic waves to the one or more protrusions 221 of the second eyelet member 220, the one or more recesses of the first eyelet member 210, and the sheet 100 under a predetermined pressure, so that the sheet 100 around the one or more protrusions 221 of the second eyelet member 220 and the one or more recesses of the first eyelet member 210 becomes integrated with the one or more protrusions 221 of the second eyelet member 220 and the one or more recesses of the first eyelet member 210, thereby adhering the eyelet 200 to the sheet 100.

[0062] For example, fusing the eyelet 200 to the sheet 100 is (a) applying a predetermined pressure to the eyelet 200 and the sheet 100 while oscillating ultrasonic waves to the eyelet 200 and the sheet 100 for a first time period, thereby bonding the eyelet 200 to the sheet 100; (b) stopping the ultrasonic oscillation and continuing to apply a predetermined pressure to the eyelet 200 and the sheet 100 for a second period of time; This can be achieved by performing the following:

[0063] The first time in step (a) is a melting time for fusing the eyelet 200 and the sheet 100 by oscillating ultrasonic waves to the eyelet 200 and the sheet 100 while pressing the eyelet 200 and the sheet 100 together at a predetermined pressure. The first time (melting time) is, for example, about 0.15 seconds to about 0.4 seconds, and preferably about 0.2 seconds to about 0.3 seconds. The second time in step (b) is a solidification time for further pressing the fused eyelet 200 and the sheet 100 together at a predetermined pressure. The second time (solidification time) is, for example, about 0.2 seconds to about 0.3 seconds, and preferably about 0.23 seconds to about 0.28 seconds. EXAMPLES

[0064] Using the apparatus 300 shown in FIG. 3, the eyelets 200 were fused to various sheets 100 under various melting time and solidification time conditions, and sheet products 10 provided with the eyelets 200 were manufactured.

[0065] <Manufacturing conditions> The conditions common to all of Examples 1 to 9 described below are as follows. Device 300 voltage: AC200V Device 300 current: 10A Output of device 300: approx. 1400W Frequency of ultrasonic waves from ultrasonic source 330: Approximately 20 kHz Pressure from pressure source 340: Approximately 0.6MPa to approximately 0.8MPa Sheet: Polyethylene Eyelets: Polyethylene Test room temperature: 22℃

[0066] The melting time, solidification time, and sheet conditions for each of Examples 1 to 9 are as follows. In Table 1, the sheet with a thickness of 0.35 mm is designated as "Type 1," and the sheet with a thickness of 0.22 mm is designated as "Type 2." [Table 1]

[0067] <Strength test method> In this specification, "JIS L1096 trapezoid method strength test" refers to a test carried out according to the following procedure.

[0068] procedure As shown in FIG. 5A, a test piece of a sheet product 10 of 200 mm×50 mm is prepared. In the test piece, the eyelet is located at approximately the center in the longitudinal direction and adjacent to one edge in the lateral direction. A cut is made several centimeters (for example, 3 cm) from one edge in the lateral direction to the eyelet. Next, a gripping line is drawn on the test piece so as to form a trapezoid with an upper base of 40 mm and a lower base of 70 mm, so that the line connecting the center of the upper base and the center of the lower base of the trapezoid is aligned with the center of the eyelet 200. Next, as shown in FIG. 5B, the test piece is gripped along the gripping line using a gripping member, and the test piece is pulled in the longitudinal direction of the test piece. As shown in FIG. 5C, the strength test is completed when the test piece breaks to approximately the center in the lateral direction. The measuring device used in the "JIS L1096 Trapezoid Method Strength Test" is, for example, the AG-10kNG manufactured by SHIMADZU.

[0069] The strength of the eyelets 200 in the sheet products 10 manufactured in each of Examples 1 to 9 was measured by a trapezoid strength test of JIS L1096. For comparison, the strength of sheets without eyelets was also measured as Examples 10 and 11. The test method of the JIS L1096 trapezoid strength test in Examples 10 and 11 was the same as that in Examples 1 to 9, except for the presence or absence of eyelets. In addition, in each Example, the same JIS L1096 trapezoid strength test was performed three or four times, taking into account the variation in the state of the sheet product 10 due to the manufacturing process. For example, in Example 1, four sheet products were manufactured under the conditions of Example 1, and the JIS L1096 trapezoid strength test was performed on each of the four sheet products. For example, in Example 2, three sheet products were manufactured under the conditions of Example 2, and the JIS L1096 trapezoid strength test was performed on each of the three sheet products.

[0070] <Strength test results> 6A and 6B show graphs of the strength of the grommets 200 in the sheet products 10 produced in each of Examples 1 to 9, and the strength of the sheets without grommets in Examples 10 and 11. In each of the graphs for Examples 1 to 11, the magnitude of the load (i.e., strength) is shown on the vertical axis, and the amount of movement of the gripping members due to the gripping members pulling the sheet product is shown on the horizontal axis.

[0071] In each example, the average value of the strengths of the eyelets 200 measured multiple times is shown in Table 2 as the "strength of the eyelets in the sheet product," and the average value of the strengths of the sheet without eyelets is shown in Table 2 as the "strength of the sheet without eyelets." [Table 2]

[0072] Comparing the test results of Example 1 and Example 10, in the sheet product 10 having the Type 1 sheet, the strength of the grommets 200 in the sheet product 10 was 140.9 / 120.3=approximately 117% of the strength of a sheet without grommets.

[0073] Comparing the test results of Example 4 and Example 10, in the sheet product 10 having the Type 1 sheet, the strength of the grommets 200 in the sheet product 10 was 192.5 / 120.3=approximately 160% of the strength of a sheet without grommets.

[0074] Comparing the test results of Example 8 and Example 11, in the sheet product 10 having the type 2 sheet, the strength of the grommets 200 in the sheet product 10 was 140.3 / 109.9=approximately 128% of the strength of a sheet without grommets.

[0075] <Strength test evaluation> From the test results of Examples 1 & 10, 4 & 10, and 8 & 11, it was found that the strength of the eyelets 200 in the sheet product 10 was approximately 100% or more of the strength of a sheet without eyelets. Furthermore, from the test results of Examples 4 & 10 and 8 & 11, the increase rate of the strength of the eyelets in the sheet product was 160%÷128%=1.25, so in the case of a sheet product having a sheet with a sheet thickness of 0.35 mm, it can be estimated that the strength of the eyelets in the sheet product is 160×1.25=approximately 200% of the strength of a sheet without eyelets. From the above, it was found that, even though the sheet 100 and the eyelets 200 were partially melted, the strength of the eyelets 200 in the sheet product 10 was approximately 100% or more (specifically, approximately 110% to approximately 200%) compared to the strength of a sheet without eyelets, regardless of the sheet type, and in particular, in sheet products having type 1 or type 2 sheets, the strength was approximately 110% to approximately 160%.

[0076] Comparing the test results of Examples 1 & 10 with the test results of Examples 8 & 11, it was found that only the sheet type was different, and the strength of the eyelets 200 in the sheet product 10 relative to the strength of a sheet without eyelets was approximately 120% in both cases, indicating that the strength of the eyelets 200 in the sheet product 10 relative to the strength of a sheet without eyelets has a similar tendency regardless of the sheet type.

[0077] It was found that when the melting time was 0.43 seconds, the sheet 100 and the eyelet 200 were burnt regardless of the length of the solidification time, and when the melting time was 0.1 seconds or less, the eyelet 200 was not sufficiently adhered to the sheet 100 regardless of the length of the solidification time, so that the melting time is preferably from about 0.15 seconds to about 0.4 seconds, and more preferably from about 0.2 seconds to about 0.3 seconds.

[0078] It was found that when the solidification time was less than 0.2 seconds, the eyelet 200 did not adhere sufficiently to the sheet 100 regardless of the length of the melting time, and therefore the solidification time is preferably at least about 0.2 seconds, more preferably from about 0.2 seconds to about 0.3 seconds, and even more preferably from about 0.23 seconds to about 0.28 seconds.

[0079] In this manner, by fusing the eyelets 200 to the sheet 100 using both the melting time and the solidification time at appropriate lengths, it is possible to manufacture a sheet product 10 with eyelets that has sufficient strength greater than the strength of the sheet 100 without eyelets.

[0080] As described above, the present invention has been illustrated using the preferred embodiment of the present invention, but the present invention should not be interpreted as being limited to this embodiment. It is understood that the scope of the present invention should be interpreted only by the claims. It is understood that a person skilled in the art can implement an equivalent scope based on the description of the present invention and technical common sense from the description of the specific preferred embodiment of the present invention. [Industrial Applicability]

[0081] INDUSTRIAL APPLICABILITY The present invention is useful for providing a sheet product or the like having sufficient eyelet strength by fusing eyelets to a sheet. [Explanation of symbols]

[0082] 10 Sheet products 100 sheets 110 One or more perforations 200 Eyelets 210 First eyelet member 220 Second eyelet member 300 equipment 310 Processor Section 320 Memory section 330 Ultrasonic Source 340 Pressure Source 350 Processing Area 360 Slender Members 370 Means of transport 380 Switch

Claims

1. 1. A method for manufacturing a sheet product having grommets, the method comprising: Providing a sheet having one or more perforations; Positioning the grommet such that the grommet contacts the sheet around the one or more perforations; fusing the eyelet to the sheet using ultrasonic waves under a predetermined pressure; Including, Fusing the eyelet to the sheet using the ultrasonic wave under the predetermined pressure the ultrasonic waves are oscillated to the eyelet and the sheet for a first time while applying the predetermined pressure to the eyelet and the sheet, thereby bonding the eyelet to the sheet, the first time being 0.15 seconds to 0.4 seconds; stopping the oscillation of the ultrasonic wave and continuing to apply the predetermined pressure to the eyelet and the sheet for a second time period, the second time period being 0.2 seconds to 0.3 seconds; Including, The frequency of the ultrasonic wave is 15 kHz to 25 kHz, The predetermined pressure is 0.6 MPa to 0.8 MPa, The eyelet is made of polyethylene, and the sheet is made of polyethylene, The method of claim 1, wherein in a strength test by the trapezoid method of JIS L1096, the strength of the eyelets in the sheet product is 110% to 200% of the strength of a sheet without the eyelets.

2. 2. The method of claim 1, wherein the first time period is between 0.2 seconds and 0.3 seconds, and the second time period is between 0.23 seconds and 0.28 seconds.

3. The eyelet has a circular ring shape, 2. The method of claim 1, wherein the outer diameter of the eyelet is between 28 mm and 40 mm and the inner diameter of the eyelet is between 11 mm and 20 mm.

4. The eyelet is constituted by a first eyelet member and a second eyelet member, Positioning the grommet such that the grommet contacts the sheet around the one or more perforations includes sandwiching the sheet around the one or more perforations between the first grommet member and the second grommet member; 2. The method of claim 1, wherein fusing the eyelet to the sheet using ultrasonic waves under the predetermined pressure comprises: oscillating the ultrasonic waves to the first eyelet member, the second eyelet member, and the sheet under the predetermined pressure while the sheet around the one or more perforations is sandwiched between the first eyelet member and the second eyelet member.

5. The second grommet member has one or more protrusions, The first grommet member has one or more recesses corresponding to the one or more protrusions, Fusing the eyelet to the sheet using the ultrasonic wave under the predetermined pressure By applying the ultrasonic waves to the one or more protrusions, the one or more recesses, and the sheet under the predetermined pressure, the sheet around the one or more protrusions and the one or more recesses is integrated with the one or more protrusions and the one or more recesses, and the eyelet is bonded to the sheet. The method of claim 4 , comprising:

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