Method for manufacturing fiber-reinforced resin material processed product and laser processing device

Abstract

To provide a method for manufacturing a fiber-reinforced resin material processed product in which fraying of reinforcing fibers and delamination between layers are suppressed even when laser processing is performed at a relatively high scanning speed, and a laser processing device usable therefor.SOLUTION: In one aspect, a method for manufacturing a fiber-reinforced resin material processed product according to the present invention includes a step of removing a fiber-reinforced resin material containing a plurality of reinforcing fibers and resin using laser light, and in the fiber-reinforced resin material, the reinforcing fibers are entangled with other reinforcing fibers.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a fiber-reinforced resin material product and a laser processing device. [Background technology]

[0002] Fiber reinforced plastics (FRP), which use fibers such as glass fiber as reinforcing materials, are lightweight, high-strength, and highly elastic materials, and are widely used in components for small ships, automobiles, railway vehicles, etc. Furthermore, carbon fiber reinforced plastics (CFRP), which use carbon fiber as a reinforcing material, have been developed with the aim of achieving even greater weight reduction, strength, and elasticity, and are used in components for aircraft, automobiles, etc.

[0003] Such fiber-reinforced plastics are known to be difficult to process because the matrix resin and reinforcing fibers have different properties. [Patent Document 1] proposes a laser processing method for laser processing an object made of a fiber-reinforced composite material containing a base material and fibers having a thermal conductivity and processing threshold higher than those of glass fiber, the method including: processing the object by irradiating the object with pulsed laser light from the processing head while moving the object and a processing head relative to each other in a predetermined cutting direction, thereby forming a plurality of through holes that penetrate the object; the pulsed laser light has a pulse width of less than 1 ms and an energy density sufficient to form the through holes with one pulse. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2020 / 115797 Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, from the viewpoint of productivity, it is preferable to process a member in a short time. In particular, in laser processing, the cost can vary depending on the irradiation time of the laser beam, so it is preferable to be able to scan the laser beam at high speed.

[0006] However, when the inventors performed laser processing on fiber-reinforced plastic at a high scanning speed, they encountered the problem that fraying of the fibers and peeling between the layers that make up the fiber-reinforced plastic were likely to occur near the cross section of the processed fiber-reinforced plastic.

[0007] Therefore, in view of the above problems, an object of the present invention is to provide a method for manufacturing a fiber-reinforced resin material processed product in which fraying of reinforcing fibers and delamination are suppressed even when laser processing is performed at a relatively high scanning speed, and a laser processing device that can be used for this method. [Means for solving the problem]

[0008] As a result of intensive research to achieve the above-mentioned object, the inventors have discovered that by entangling the reinforcing fibers in the fiber-reinforced resin material to be processed, it is possible to suppress fraying and delamination of the reinforcing fibers in the processed portion of the fiber-reinforced resin material product, even when laser processing is performed at a relatively high scanning speed. As a result of further intensive research, they have arrived at the present invention.

[0009] The gist of the present invention is as follows. [1] A method for manufacturing a fiber-reinforced resin material including a plurality of reinforcing fibers and a resin, comprising: The method for manufacturing a fiber-reinforced resin material processed product, wherein the reinforcing fibers in the fiber-reinforced resin material are entangled with other reinforcing fibers. [2] The laser beam is a pulsed laser beam, [1] A method for manufacturing a fiber-reinforced resin material processed product according to [1], wherein in the step, the removal processing is performed by irradiating the fiber-reinforced resin material with the pulsed laser light to form a plurality of through holes in the fiber-reinforced resin material, and each through hole is formed by irradiating the pulsed laser light once. [3] The method for producing a fiber-reinforced resin material processed product according to [1] or [2], wherein the reinforcing fibers in the fiber-reinforced resin material are entangled with each other by needle punching. [4] The method for producing a fiber-reinforced resin material processed product according to any one of [1] to [3], wherein the fiber-reinforced resin material is molded using a needle-punched nonwoven fabric containing the reinforcing fibers as a reinforcing fiber substrate. [5] The method for producing a fiber-reinforced resin material processed product according to any one of [1] to [4], wherein the reinforcing fibers include recycled reinforcing fibers. [6] The method for producing a fiber-reinforced resin material product according to any one of [1] to [5], wherein the reinforcing fibers include carbon fibers. [7] A laser processing device used in the method for producing a fiber-reinforced resin material product according to any one of [1] to [6]. [Effects of the Invention]

[0010] As described above, according to the present invention, it is possible to provide a method for manufacturing a fiber-reinforced resin material processed product in which fraying of the reinforcing fibers and delamination between layers are suppressed even when laser processing is performed at a relatively high scanning speed, and a laser processing device that can be used for this method. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional schematic view of a fiber reinforced resin material used in a method for producing a fiber reinforced resin material product according to one embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram showing an example of the functional configuration of a laser processing device used in a method for producing a fiber-reinforced resin material product according to one embodiment of the present invention. [Figure 3] FIG. 3 is a schematic diagram showing an example of a hardware configuration of the laser processing apparatus shown in FIG. [Figure 4] FIG. 4 is a block diagram showing a hardware configuration for realizing the functions of the control unit of the laser processing apparatus shown in FIG. [Figure 5] FIG. 5 is a schematic diagram for explaining a laser processing method in a method for producing a fiber-reinforced resin material product according to one embodiment of the present invention. [Figure 6] FIG. 6 is a graph showing an example of an output waveform of a pulse laser, which is a pulse laser beam outputted in the laser processing apparatus shown in FIG. [Figure 7] FIG. 7 is a schematic diagram for explaining the relationship between the overlap ratio of the holes that overlap each other in laser processing using a pulsed laser beam and the number of times of irradiation with the pulsed laser beam. [Figure 8] FIG. 8 is a schematic diagram for explaining the relationship between the overlap ratio of the holes that overlap each other in laser processing using a pulsed laser beam and the number of times of irradiation with the pulsed laser beam. [Figure 9] FIG. 9 is a schematic diagram for explaining the relationship between the overlap ratio of the holes that overlap each other in laser processing using a pulsed laser beam and the number of times of irradiation with the pulsed laser beam. [Figure 10] FIG. 10 is a photographic image of a fiber reinforced resin material product manufactured by the method for manufacturing a fiber reinforced resin material product according to the embodiment. [Figure 11] FIG. 11 is a partially enlarged photographic image of the fiber-reinforced resin material processed product shown in FIG. [Figure 12] FIG. 12 is an enlarged photographic image of a fiber reinforced resin material product manufactured by a method for manufacturing a fiber reinforced resin material product according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method for manufacturing a fiber-reinforced resin material product and a laser processing apparatus according to the present invention will be described in detail below with reference to the drawings.

[0013] FIG. 1 is a cross-sectional schematic diagram of a fiber-reinforced resin material used in a manufacturing method for a fiber-reinforced resin material product according to one embodiment of the present invention. FIG. 2 is a block diagram showing an example of the functional configuration of a laser processing apparatus used in a manufacturing method for a fiber-reinforced resin material product according to one embodiment of the present invention. FIG. 3 is a schematic diagram showing an example of the hardware configuration of the laser processing apparatus shown in FIG. 2. FIG. 4 is a block diagram showing a hardware configuration for realizing the functions of the control unit of the laser processing apparatus shown in FIG. 2. FIG. 5 is a schematic diagram for explaining the laser processing method in the manufacturing method for a fiber-reinforced resin material product according to one embodiment of the present invention. FIG. 6 is a graph showing an example of the output waveform of a pulsed laser, which is the pulsed laser light output by the laser processing apparatus shown in FIG. 2. FIGS. 7 to 9 are schematic diagrams for explaining the relationship between the overlap ratio of holes machined with pulsed laser light and the number of irradiations of the pulsed laser light during laser processing using pulsed laser light. Note that, for ease of explanation, components that do not require explanation have been omitted from the figures. Furthermore, the dimensions of the illustrated components have been appropriately enlarged or reduced for ease of explanation and do not represent the actual size of each component.

[0014] The method for manufacturing a fiber-reinforced resin material product of the present invention includes a process (processing process) of removing a fiber-reinforced resin material containing a plurality of reinforcing fibers and a resin using a laser beam, and in the fiber-reinforced resin material, the reinforcing fibers are entangled with other reinforcing fibers. Furthermore, in this embodiment, the method includes a preparation process of preparing a fiber-reinforced resin material containing reinforcing fibers and a resin material prior to the processing process. Each process will be described in detail below.

[0015] <1. Preparation process> First, in this process, a fiber-reinforced resin material containing a plurality of reinforcing fibers and a resin material is prepared. Such a fiber-reinforced resin material is not particularly limited as long as the reinforcing fibers are entangled with each other. Specific examples of fiber-reinforced resin materials that can be used in this embodiment and their manufacturing methods are described below.

[0016] (1.1. Fiber-reinforced resin materials) The fiber-reinforced resin material that can be used in this embodiment is a resin material that is reinforced by embedding reinforcing fibers in a matrix resin (also simply referred to as "resin"). Such fiber-reinforced resin materials are not particularly limited, and examples thereof include carbon fiber reinforced plastics (CFRP), glass fiber reinforced plastics (GFRP), long glass fiber mat reinforced thermoplastics (GMT), aramid fiber reinforced plastics (AFRP), Kevlar fiber reinforced plastics (KFRP), Dyneema fiber reinforced plastics (DFRP), basalt fiber reinforced plastic, boron fiber reinforced plastic, hemp fiber reinforced plastic, kenaf fiber reinforced plastic, bamboo fiber reinforced plastic, palm fiber reinforced plastic, wood fiber reinforced plastic, and cotton fiber reinforced plastic.

[0017] An example of a fiber-reinforced resin material is shown in Figure 1. Figure 1 is a cross-sectional schematic diagram of a fiber-reinforced resin material that can be used in this embodiment. As shown in Figure 1, the fiber-reinforced resin material 1 includes a reinforcing fiber layer 10 including a plurality of laminated sheet-like substrates 11, and a matrix resin 20.

[0018] In this embodiment, each substrate 11 is a nonwoven fiber web. As shown in the enlarged view of Fig. 1, the reinforcing fibers 13 in the substrate 11 are entangled with each other at random positions, thereby fixing the reinforcing fibers 13 in the substrate 11 to each other.

[0019] Furthermore, since both a certain substrate 11 and an adjacent substrate 11 are nonwoven fiber webs, the reinforcing fibers 13 of the adjacent substrates 11 are entangled with each other during press molding, and the substrates 11 are fixed together.

[0020] Methods for entangling the reinforcing fibers 13 include needle punching, water jet, air jet, fibrid, etc. Among these, the reinforcing fibers 13 have relatively high rigidity, so it is preferable that the base material 11 includes a needle punched nonwoven fabric in which the reinforcing fibers 13 are entangled by needle punching.

[0021] The reinforcing fibers 13 contained in the substrate 11 are not particularly limited, but examples thereof include carbon fibers, glass fibers, aramid fibers, Kevlar fibers, Dyneema fibers, basalt fibers, and boron fibers, and one of these can be used alone or two or more can be used in combination. Examples of carbon fibers include PAN (polyacrylonitrile)-based carbon fibers, pitch-based carbon fibers, and rayon-based carbon fibers, and one or both can be used.

[0022] Among the above, the reinforcing fibers 13 contained in the substrate 11 preferably include one or more types selected from the group consisting of carbon fibers and glass fibers, more preferably carbon fibers. Each of these reinforcing fibers 13 has appropriate flexibility, and by using such reinforcing fibers 13, the reinforcing fibers 13 can be more easily entangled with each other.

[0023] Furthermore, the reinforcing fibers 13 contained in each substrate 11 preferably account for 10 mass % or more, more preferably 25 mass % or more of the above-described preferred reinforcing fibers. More preferably, the reinforcing fibers 13 contained in each substrate 11 are substantially composed of the above-described preferred reinforcing fibers, and particularly, the reinforcing fibers 13 contained in each substrate 11 are composed of the above-described preferred reinforcing fibers. This allows the reinforcing fibers 13 to be more easily entangled with each other.

[0024] The reinforcing fibers 13 may be unused, i.e., virgin reinforcing fibers, recycled reinforcing fibers that have been recycled from reinforcing fibers already used in fiber-reinforced plastics, or a mixture of these. In many cases, recycled reinforcing fibers are collected in a random orientation, making them suitable as the reinforcing fibers 13 of the fiber-reinforced resin material 1 of this embodiment.

[0025] In the illustrated embodiment, the reinforcing fiber layer 10 is formed of a laminated sheet-like substrate 11, but the present invention is not limited to this. For example, all or some of the substrates may be chip-shaped, and the chip-shaped substrates may be arranged regularly or irregularly to form the reinforcing fiber layer as a whole. The reinforcing fiber layer may also be formed of a single substrate. The shape of the reinforcing fiber layer is not limited to the plate shape shown in the figure, and may be any shape as long as it can be laser-machined.

[0026] Furthermore, not all of the substrates 11 in the reinforcing fiber layer 10 need to be nonwoven fabrics as described above. For example, some of the substrates 11 in the reinforcing fiber layer 10 may be in the form of fiber bundles (tows) in which a plurality of reinforcing fibers are aligned in one direction, or in the form of a woven or nonwoven fabric in which fiber bundles of reinforcing fibers are used as warp and weft threads, or in which the reinforcing fibers are arranged in random positions and directions. Furthermore, without being limited to the illustrated embodiment, the reinforcing fiber layer 10 does not need to have a nonwoven fabric as described above as long as the reinforcing fibers 13 are entangled with each other.

[0027] The matrix resin (hereinafter also simply referred to as "resin") 20 in the fiber reinforced resin material 1 fills the gaps in the reinforcing fiber layer 10 (gaps between the reinforcing fibers 13) and embeds the reinforcing fiber layer 10. The resin 20 in the fiber reinforced resin material 1 is not particularly limited and may be, for example, either a thermosetting resin or a thermoplastic resin. Furthermore, the thermosetting resin may be uncured or cured.

[0028] The thermosetting resin is not particularly limited, but examples thereof include epoxy resins, unsaturated polyester resins, vinyl ester resins, phenolic resins, cyanate resins, polycarbonate resins, polyacetal resins, etc., and one of these can be used alone or two or more can be used in combination.

[0029] The thermoplastic resin is not particularly limited, but examples thereof include polyolefin, polyester, polycarbonate, acrylic resin, acrylonitrile-butadiene-styrene copolymer, polyether ketone, polyphenylene sulfide, etc., and one of these can be used alone or two or more can be used in combination.

[0030] (1.2. Manufacturing of Fiber-Reinforced Resin Materials) Next, we will explain an example of a method for manufacturing the above-mentioned fiber reinforced resin material 1. The fiber reinforced resin material 1 can be obtained, for example, by molding one or more base materials 11 containing reinforcing fibers 13 together with resin 20.

[0031] In this embodiment, first, a nonwoven fiber web of reinforcing fibers 13 to which resin 20 has been added is formed. Examples of nonwoven fiber webs to which resin 20 has been added include those in which the resin 20 is used as resin fibers and a nonwoven web is formed using the resin fibers and reinforcing fibers 13. By forming a nonwoven web using resin fibers and reinforcing fibers 13 in this way, when producing a fiber-reinforced resin material 1, the resin 20 can be more reliably filled between the reinforcing fibers 13. Furthermore, the step of liquefying the resin 20 and impregnating the reinforcing fibers 13 can be omitted. Furthermore, the content of resin 20 in the fiber-reinforced resin material 1 can be easily adjusted.

[0032] Specifically, for example, a nonwoven fiber web can be formed by mixing reinforcing fibers 13 and resin fibers. The method for forming the nonwoven fiber web is not particularly limited, and either a dry method or a wet method, such as carding, can be used. That is, the nonwoven fiber web can include a dry nonwoven fabric and / or a wet nonwoven fabric, such as a carded fiber web. Alternatively, a resin fiber web can be formed by a spunbond method or a meltblown method, and then combined with a carbon fiber web formed by a wet method or a dry method.

[0033] Then, if necessary, a plurality of nonwoven fiber webs may be appropriately laminated to obtain a desired basis weight of the reinforcing fibers 13. The nonwoven fiber webs may be laminated using any of a unidirectional web, a cross-lay web, and a criss-cross web.

[0034] Furthermore, fibers in a nonwoven fiber web may be bonded to each other in order to bond multiple stacked nonwoven fiber webs or to adjust the thickness of a single nonwoven fiber web. Examples of bonding methods include impregnation, spraying, or application of an emulsion or solution containing an adhesive resin, or heating and fusing the nonwoven fiber web. Alternatively, the above-mentioned objectives may be achieved by placing a resin sheet on the nonwoven fiber web and pressing it.

[0035] Next, the reinforcing fibers 13 in the nonwoven fiber web are entangled with each other to obtain the substrate 11. Examples of entanglement methods include needle punching, water jetting, air jetting, and fibrid. Among the above methods, it is preferable to entangle the fibers in the nonwoven fiber web with each other by needle punching, because the reinforcing fibers 13 themselves do not melt and have rigidity.

[0036] The substrate 11 does not have to be produced by the method described above, and may be obtained, for example, by forming a substrate 11 in which reinforcing fibers 13 that do not contain resin 20 are entangled, and then applying a solution of resin 20 to the substrate by immersion, spraying, etc. Alternatively, the substrate 11 may be obtained by applying a solution of resin 20 to a nonwoven fiber web that does not contain resin 20 by immersion, spraying, etc. to obtain a nonwoven fiber web that contains resin 20, and then performing an entanglement treatment on the nonwoven fiber web.

[0037] Next, the substrate 11 to which one or more resins 20 have been applied is molded to obtain the fiber-reinforced resin material 1. The molding method is not particularly limited, but press molding, for example, can be used. The press molding device can be appropriately selected depending on the type of resin 20 and reinforcing fiber 13 and the fiber-reinforced resin material 1 to be produced, and for example, a heat and cool press molding device can be used.

[0038] The pressing conditions can be changed as appropriate depending on the type of resin constituting the fiber reinforced resin material 1, but the pressing temperature can be, for example, 150°C or higher and 500°C or lower, preferably 180°C or higher and 400°C or lower, and more preferably 200°C or higher and 350°C or lower. The pressing pressure can be, for example, 5.0 kgf / cm. 2 More than 2,500Kgf / cm 2 Less than 50 kgf / cm 2 More than 1,000Kgf / cm 2 Less than or equal to 100 kgf / cm 2 More than 500Kgf / cm 2 The pressing time can be, for example, from 30 seconds to 3,600 seconds, preferably from 60 seconds to 1,800 seconds, and more preferably from 180 seconds to 600 seconds.

[0039] Although an example of a method for manufacturing the fiber reinforced resin material 1 has been described above, the method for manufacturing the fiber reinforced resin material 1 according to this embodiment is not limited to this, and the fiber reinforced resin material 1 may be manufactured by any manufacturing method. Furthermore, the fiber reinforced resin material 1 may be prepared by purchasing a commercially available fiber reinforced resin material 1 without manufacturing the fiber reinforced resin material 1.

[0040] <2. Processing process> In this step, the fiber reinforced resin material 1 is removed using laser light. First, an example of a laser processing device used in this step will be described, and then a laser processing method will be described.

[0041] (2.1. Laser processing equipment) The laser processing apparatus 100 shown in FIGS. 2 to 4 has a function of irradiating a workpiece W with pulsed laser light PL to perform removal processing (e.g., cutting processing) of the workpiece W. In this embodiment, the workpiece W is a fiber-reinforced resin material 1. The laser processing apparatus 100 also has a laser oscillator 111, an optical path 112, a processing head 113, a drive unit 114, a nozzle 115, a nozzle moving mechanism 116, a detection unit 117, and a control unit 118.

[0042] The laser oscillator 111 oscillates and emits pulsed laser light PL. The laser oscillator 111 used in the laser processing apparatus 100 is not particularly limited, but a CO2 laser oscillator is preferable. That is, the pulsed laser light PL used in the laser processing apparatus 100 is not particularly limited, but a CO2 laser beam is preferable. For example, laser light emitted from a fiber laser is not absorbed by resin. Therefore, when laser light emitted from a fiber laser is used, the resin is heated and removed by heat transferred from the reinforcing fiber to the resin. In contrast, CO2 laser light has a higher absorption rate in resin than laser light emitted from a fiber laser. Therefore, since there is no need for heat transfer time, it is possible to process a through hole in a shorter time and with a smaller heat input. Therefore, using a CO2 laser beam in the laser processing apparatus 100 enables cutting processing that is more efficient and less affected by heat.

[0043] The pulsed laser light PL emitted from the laser oscillator 111 is supplied to the processing head 113 via an optical path 112. The optical path 112 is a path for transmitting the pulsed laser light PL emitted from the laser oscillator 111 to the processing head 113, and may be a path for propagating the pulsed laser light PL in the air or a path for transmitting the pulsed laser light PL through an optical fiber. The optical path 112 is designed in accordance with the characteristics of the pulsed laser light PL.

[0044] The processing head 113 has an optical system that focuses the pulsed laser light PL on the work-piece W. The processing head 113 focuses the supplied pulsed laser light PL and irradiates one side of the work-piece W, which is the surface to be processed of the work-piece W. It is desirable that the processing head 113 has an optical system that focuses the light near the surface of the work-piece W.

[0045] The drive unit 114 can control and change the relative positional relationship between the processing head 113 and the workpiece W. In the laser processing apparatus 100, the drive unit 114 changes the position of the processing head 113 to change the relative positional relationship between the processing head 113 and the workpiece W, but is not limited to the illustrated embodiment, and the drive unit 114 may change the position of a table on which the workpiece W is placed, or may change the positions of both the processing head 113 and the table on which the workpiece W is placed. In other words, the drive unit 114 only needs to have the function of changing the position of at least one of the processing head 113 and the workpiece W.

[0046] The drive unit 114 changes the relative positional relationship between the processing head 113 and the workpiece W, and the processing head 113 irradiates the workpiece W with pulsed laser light PL, thereby cutting the workpiece W.

[0047] The nozzle 115 is a gas injection nozzle that injects gas 123 onto a portion of the work-piece W that is irradiated with the pulsed laser beam PL from the processing head 113. The nozzle 115 injects the gas 123 from outside the optical axis PLa of the pulsed laser beam PL that is irradiated from the processing head 113 onto the work-piece W toward the optical axis PLa. More specifically, the nozzle 115 injects the gas 123 from outside the optical axis PLa of the pulsed laser beam PL that is irradiated from the processing head 113 onto the work-piece W toward a processing point on the work-piece W that is to be processed by the pulsed laser beam PL. The position of the nozzle 115 is changed by a nozzle moving mechanism 116. The position of the nozzle 115 can be moved to any position under the control of a control unit 118 while the work-piece W is being processed.

[0048] 2, the nozzle 115 is a side flow nozzle, which supplies the gas 123 from the side with respect to the optical axis PLa of the pulsed laser beam PL. When the workpiece W is cut in the laser processing apparatus 100, the ejection direction of the decomposition products 130 tends to coincide with the optical axis PLa. Therefore, by employing a side flow nozzle, it is possible to prevent a blind hole, which is a hole in the middle of forming a through hole, from obstructing the flow of the gas 123.

[0049] The detection unit 117 is a sensor that detects the state of the workpiece W or the state of the laser processing apparatus 100. The detection unit 117 measures, as time-series signals, the position of the workpiece W being processed, the intensity and wavelength of light generated during processing, sound waves, ultrasonic waves, and other physical quantities. The detection unit 117 is, for example, a capacitance sensor, a photodiode, a CCD (Charge Coupled Device) sensor, a CMOS (Complementary Metal Oxide Semiconductor) sensor, a spectrometer, an acoustic sensor, an acceleration sensor, a gyro sensor, a distance sensor, a position detector, a temperature sensor, or a humidity sensor. The detection unit 117 inputs the time-series signals indicating the measurement values ​​to the control unit 118.

[0050] The control unit 118 controls each unit of the laser processing apparatus 100, such as the laser oscillator 111, the drive unit 114, and the nozzle moving mechanism 116, so that the pulsed laser beam PL scans a processing path on the workpiece W in accordance with the set processing conditions and measurement values ​​transmitted from the detection unit 117. The processing conditions include, for example, the material, thickness, and surface condition of the workpiece W. The processing conditions further include the laser output intensity, laser output frequency, laser output duty ratio, mode, waveform, and wavelength of the laser oscillator 111. The processing conditions may include the focal position of the pulsed laser beam PL, the focused diameter of the pulsed laser beam PL, the type of gas ejected from the nozzle 115, the gas pressure, the nozzle hole diameter, the processing speed, and the like. The processing conditions may also include measurement values ​​input from the detection unit 117, such as the distance between the workpiece W and the processing head 113, temperature, and humidity.

[0051] FIG. 4 is a diagram showing a hardware (control device) configuration for realizing the functions of the control unit 118 shown in FIG. 2. As shown in FIG. 4, the functions of the control unit 118 of the laser processing apparatus 100 are realized by a control device including a CPU (Central Processing Unit) 201, a memory 202, a storage device 203, a display device 204, and an input device 205. The functions executed by the control unit 118 are realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a computer program and stored in the storage device 203. The CPU 201 reads the software or firmware stored in the storage device 203 into the memory 202 and executes it to realize the functions of the control unit 118. That is, the control device includes the storage device 203 for storing programs that result in the execution of steps that perform the operations of the control unit 118 when the functions of the control unit 118 are executed by the CPU 201. These programs can also be said to cause the control device to execute the processes realized by the functions of the control unit 118. The memory 202 corresponds to a volatile storage area such as a RAM (Random Access Memory). The storage device 203 may be a non-volatile or volatile semiconductor memory such as a ROM (Read Only Memory) or a flash memory, or a magnetic disk. Specific examples of the display device 204 include a monitor and a display. Specific examples of the input device 205 include a keyboard, a mouse, a touch panel, a microphone, etc.

[0052] The optical unit 122 shown in FIG. 3 includes a condenser lens 121 that condenses the pulsed laser light PL onto the processing point, and is a part of the processing head 113 shown in FIG.

[0053] The laser processing apparatus 100 irradiates one surface of the workpiece W with pulsed laser light PL to perform removal processing on the workpiece W. For example, it performs cutting processing to separate the workpiece W into a workpiece 129 and scrap material 128. The position at which the pulsed laser light PL is irradiated on the workpiece W is controlled by the control unit 118, and the workpiece moves along a processing path.

[0054] (2.2. Removal processing) Using the laser processing apparatus 100 as described above, removal processing is performed on a fiber-reinforced resin material 1 (work-piece W). Specifically, in removal processing of the work-piece W, the pulsed laser beam PL is focused on the surface of the work-piece W by the focusing lens 121 as shown in FIGS. 3 and 5. The pulsed laser beam PL is scanned and irradiated on the surface of the work-piece W in a predetermined cutting direction. That is, the pulsed laser beam PL is irradiated while changing the irradiation position of the pulsed laser beam PL on the work-piece W by changing the relative positional relationship between the processing head 113 and the work-piece W.

[0055] In this embodiment, the reinforcing fibers 13 in the fiber-reinforced resin material 1 are entangled with each other as shown in Fig. 1. Therefore, in this step, even when laser processing is performed at a relatively high scanning speed, fraying and delamination of the reinforcing fibers 13 are suppressed.

[0056] More specifically, when laser processing is performed using a laser processing device, heat is generated in the workpiece due to the laser irradiation. Fiber-reinforced resin materials are generally composed of reinforcing fibers and resin, and their physical properties, particularly thermal characteristics, differ significantly. Reinforcing fibers tend to have higher melting points and decomposition temperatures than resins, and also have higher thermal conductivity. In particular, when the reinforcing fibers contain carbon fiber, the melting point and decomposition temperature of carbon fiber is approximately 3500°C, while the melting point and decomposition temperature of resin is in the range of 200–400°C. In this case, the processing point temperature during laser processing is adjusted to match the reinforcing fiber's high melting point and decomposition temperature. Therefore, when laser processing fiber-reinforced resin materials, the heat generated during processing is transferred through the reinforcing fibers to the resin surrounding the processing area, potentially causing thermal damage to the resin. This can result in reduced adhesion at the interface between the reinforcing fibers and the resin, or physical separation between the reinforcing fibers and the resin due to the rapid generation and expansion of gas caused by material decomposition and thermal damage to the resin during laser processing, potentially damaging the processed area of ​​the workpiece. In particular, increasing the scanning speed inevitably increases the amount of heat input per pulsed laser beam during laser processing, which can lead to increased peeling between the reinforcing fibers and the resin, as well as increased damage to the processed area of ​​the workpiece. In particular, when the substrate is a woven fabric of reinforcing fibers, the reinforcing fibers may increase or decrease unevenly in the processed area, resulting in uneven processing conditions depending on the density difference. This can result in fraying of the reinforcing fibers and delamination of the fiber-reinforced resin material.

[0057] In contrast, in this embodiment, the reinforcing fibers 13 are entangled in the substrate 11, and therefore the entangled reinforcing fibers 13 are fixed to each other even during laser processing, making it less likely that the reinforcing fibers 13 will fray or that the fiber-reinforced resin material 1 will delaminate. Also, in this embodiment, the substrate 11 is a nonwoven fiber web, and therefore unevenness in the density of the reinforcing fibers 13 and the resin 20 will be relatively unlikely to occur in the processed area, making it easier to achieve a uniform processed state in the processed area. This results in a more consistent processed state, further reducing the likelihood of fraying of the reinforcing fibers 13 or delamination of the fiber-reinforced resin material 1.

[0058] Furthermore, the scanning speed (set speed) of the pulsed laser light PL during laser processing is not particularly limited, but is, for example, 0.5 m / min or more and 30 m / min or less, preferably 2.0 m / min or more and 20 m / min or less, and more preferably 3.0 m / min or more and 15 m / min or less for the fiber reinforced resin material 1.

[0059] As described above, generally, increasing the scanning speed tends to cause fraying and delamination of the fiber-reinforced resin material. However, in this embodiment, because the reinforcing fibers 13 are entangled in the substrate 11, fraying of the reinforcing fibers 13 and delamination of the fiber-reinforced resin material 1 can be sufficiently suppressed even when the scanning speed is increased. Furthermore, increasing the scanning speed can shorten the processing time, thereby reducing the energy used and the associated costs. In other words, the effects of the present invention are more pronounced at such high scanning speeds.

[0060] It should be noted that the above scanning speed (set speed) is the maximum scanning speed set in the laser processing apparatus 100 during laser processing, and the actual scanning speed (actual scanning speed) of the pulsed laser beam PL during laser processing is accelerated or decelerated according to the processing situation, with the set speed being the maximum speed. For example, at the start of laser processing, the initial speed of the actual scanning speed of the pulsed laser beam PL is 0 mm / min, and it accelerates to approach the set speed. Furthermore, the actual scanning speed of the pulsed laser beam PL is decelerated as necessary when cutting a curved surface or a corner. Furthermore, at the end of laser processing, the actual scanning speed of the pulsed laser beam PL is decelerated as it approaches the end position.

[0061] Furthermore, the appropriate range of the scanning speed of the pulsed laser beam PL can also vary depending on the thickness of the substrate 11 to be processed. That is, when the thickness of the substrate 11 is large, the scanning speed of the pulsed laser beam PL needs to be relatively small in order to cut the substrate 11 without problems such as delamination. On the other hand, when the thickness of the substrate 11 is small, problems are less likely to occur even if the scanning speed of the pulsed laser beam PL is relatively large.

[0062] Furthermore, when the thickness of the substrate 11 is t [mm] (where t≦3.3 [mm]) and the set speed of the pulsed laser beam PL is V [m / min], the set speed V of the pulsed laser beam PL and the thickness t of the substrate 11 satisfy the relationship of, for example, 0.2V≦14.3−3.85t≦3.0V, preferably 0.3V≦14.3−3.85t≦2.5V, and more preferably 0.5V≦14.3−3.85t≦2.0V. The present inventors have found from their experience that by satisfying the above relationship, the substrate 11 can be cut while suppressing problems such as delamination while increasing the scanning speed.

[0063] Furthermore, in this embodiment, cutting is performed as removal processing using pulsed laser light PL. In this case, the fiber reinforced resin material 1 is cut by forming continuous holes (through holes) 141 in the fiber reinforced resin material 1 with the pulsed laser light PL. Preferably, each through hole is formed by irradiating the fiber reinforced resin material 1 with a single pulse of pulsed laser light PL. This allows the fiber reinforced resin material 1 to be laser processed while suppressing the thermal influence on the resin 20 of the fiber reinforced resin material 1, and further improves the processing speed and processing quality of the fiber reinforced resin material 1 in laser processing.

[0064] This will be described in detail below. In the following description, a case will be described in which a fiber reinforced resin material 1 is scanned at a scanning speed v and cut to a cutting length L with a pulsed laser beam PL having a pulse number N, as shown in Fig. 5. N is a positive number of 2 or more.

[0065] 6 is a diagram showing the output waveform of the pulsed laser light PL outputted in the laser processing apparatus 100 shown in FIG. 1, and is a diagram showing the output waveform of a pulsed laser having enough energy to form, in a single irradiation, a processed hole 141, which is a through hole penetrating the fiber reinforced resin material 1 in the thickness direction. For example, when the irradiation position of the pulsed laser light PL is moved at a scanning speed v while the pulsed laser is repeatedly irradiated at a frequency f as shown in FIG. 6 to cut the fiber reinforced resin material 1 in a single scanning, the number of pulses N of the pulsed laser light PL irradiated onto the fiber reinforced resin material 1 is expressed by the following equation (1).

[0066] N=L×f / v (1)

[0067] When the diameter of a processed hole 141 processed by one pulse of the pulsed laser beam PL in the cutting direction of the fiber reinforced resin material 1 is defined as the processed hole diameter d, the overlap ratio ro of two processed holes adjacent to each other in the cutting direction, i.e., the degree of overlap of the processed holes in the cutting direction, is expressed by the following formula (2). The cutting direction of the fiber reinforced resin material 1 is the same as the scanning direction of the pulsed laser beam PL. The overlap ratio ro is the ratio of the overlap length of two processed holes adjacent to each other in the cutting direction to the processed hole diameter d. The processed hole diameter d is the same as the focused diameter of the pulsed laser beam PL. In other words, the processed hole diameter d can be expressed as the focused diameter d of the pulsed laser beam PL in the cutting direction of the fiber reinforced resin material 1. Note that in Figure 5 and other figures, the processed hole diameter d is illustrated as being larger than the focused diameter of the pulsed laser beam PL to make it easier to understand the overlapping state of the processed holes.

[0068] ro=(dL / N) / d (2)

[0069] In this embodiment, it is preferable that laser processing be performed with the overlap ratio ro set to a range greater than 0 and less than 0.5, as shown in the following formula (3).

[0070] 0 <ro=(d-L / N) / d<0.5···(3)

[0071] Next, it will be explained how the pulsed laser light PL irradiated so as to satisfy the condition of the above formula (3) can penetrate and cut the fiber reinforced resin material 1 in one pulse.

[0072] 7 to 9 are schematic diagrams showing the processing state of a fiber reinforced resin material 1 with the pulsed laser beam PL when the overlap ratio ro is changed. FIG. 7 is a schematic diagram showing the processing state when the processing conditions of the fiber reinforced resin material 1 with the pulsed laser beam PL do not satisfy the condition of formula (3), i.e., when the overlap ratio ro is less than 0. FIG. 8 is a schematic diagram showing the processing state when the processing conditions of the fiber reinforced resin material 1 with the pulsed laser beam PL satisfy the condition of formula (3). FIG. 9 is a schematic diagram showing the processing state when the processing conditions of the fiber reinforced resin material 1 with the pulsed laser beam PL do not satisfy the condition of formula (3), i.e., when the overlap ratio ro is 0.5 or more. Note that the nozzle 115 is not shown in FIGS. 6 to 9.

[0073] 7, when the processing conditions of the fiber reinforced resin material 1 with the pulsed laser light PL do not satisfy the condition of formula (3), and the overlap ratio ro is less than 0, this means that the processing holes 141 adjacent to each other in the cutting direction do not overlap, i.e., do not overlap. Therefore, the fiber reinforced resin material 1 cannot be cut by the processing shown in FIG.

[0074] As shown in Figure 9, when the processing conditions of the fiber reinforced resin material 1 with the pulsed laser beam PL do not satisfy the condition of formula (3), that is, when the overlap ratio ro is 0.5 or more and the overlap between two adjacent processed holes 141 in the cutting direction is greater than the condition of formula (3), the pulsed laser beam PL is irradiated two or more times over the entire cutting length L. In this case, the amount of excess heat input to the fiber reinforced resin material 1 that does not contribute to cutting increases, causing unnecessary thermal effects on the surrounding resin from the inner surface of the processed hole 141. Furthermore, the number of irradiations of the pulsed laser beam PL required to cut the cutting length L increases, and the laser energy used increases.

[0075] On the other hand, in the case shown in Fig. 8, the processing conditions of the fiber reinforced resin material 1 with the pulsed laser beam PL satisfy the condition of formula (3), and only the energy of one pulse of the pulsed laser beam PL enters the processing region 142, which is hatched in Fig. 8, in the cutting length L. The fact that the fiber reinforced resin material 1 can be cut over the cutting length L in this state indicates that the energy of one pulse of the pulsed laser beam PL is used to form a processing hole 141 that penetrates the fiber reinforced resin material 1 in the thickness direction and perform the cutting.

[0076] That is, in the case shown in Fig. 8, in the region where a processed hole is formed and cut, the region irradiated twice with the pulsed laser in the scanning direction of the pulsed laser beam PL is smaller than in the case shown in Fig. 9, and the cutting length L is cut. In other words, when the processing conditions for the fiber reinforced resin material 1 with the pulsed laser beam PL satisfy the condition of formula (3) as shown in Fig. 8, in the laser processing method in which one pulsed laser is repeatedly irradiated while moving the pulsed laser beam PL to cut, a processed hole 141 that is a through hole penetrating the fiber reinforced resin material 1 is formed by one pulsed laser irradiation, and the fiber reinforced resin material 1 is cut. This makes it possible to cut the fiber reinforced resin material 1 while suppressing the thermal influence on the resin of the fiber reinforced resin material 1.

[0077] In FIG. 8 , a processed hole 141 having a semicircular opening shape is formed by irradiation with pulsed laser light PL when n = 0. Furthermore, a processed hole 141 having a circular opening shape is formed by irradiation with pulsed laser light PL when n = N. Here, in the processed hole 141 formed when n = N, the portion necessary for cutting the cutting length L is the semicircular opening portion on the processed hole 141 formed when n = N-1. Therefore, the portion of the processed hole 141 having a semicircular opening shape formed when n = 0 and the portion of the processed hole 141 having a semicircular opening shape formed when n = N can be considered to be a single circular processed hole 141. Therefore, in the case shown in FIG. 8 , the number of pulses of the pulsed laser light PL irradiated onto the fiber reinforced resin material 1 to cut the fiber reinforced resin material 1 to the cutting length L is considered to be N.

[0078] In the cutting process of the fiber reinforced resin material 1 by the laser processing apparatus 100, it is preferable that the control unit 118 controls the drive unit 114 so as to satisfy the conditions of the above formula (3), and controls and changes the relative positional relationship between the processing head 113 and the fiber reinforced resin material 1. That is, when performing the cutting process of the fiber reinforced resin material 1, the control unit 118 preferably controls the relative positional relationship between the irradiation position of the pulsed laser light PL and the fiber reinforced resin material 1 so as to satisfy the conditions of the above formula (3).

[0079] As described above, it is preferable that the overlap ratio ro is in the range of "0 < ro < 0.5". However, it is more preferable that the overlap ratio ro is as small as possible, that is, close to 0, even in the range of "0 < ro < 0.5". By making the overlap ratio ro as small as possible, the pulsed laser light PL irradiated again on the portion of the through hole that has already penetrated can be reduced, and the excessive heat input that does not contribute to the cutting of the fiber reinforced resin material 1 can be reduced.

[0080] The optimum value of the overlap ratio ro is 0.2. When the overlap ratio ro is 0.2, the cutting speed does not decrease, and the smoothness of the cut end face also increases. That is, when the overlap ratio ro is 0.2, even if the processing holes 141 are overlapped, the decrease in the processing speed can be suppressed, and high smoothness can be obtained on the cut end face.

[0081] Next, the pulse width in the laser processing method using pulsed laser light as described above will be described. As described above, in the laser processing method, the time when the bottom of the hole exists during the formation of the through hole is approximated by the processing time Tp. Therefore, the pulse width of the pulsed laser of the pulsed laser light PL in the laser processing method is preferably as short as possible. When the pulse width of the pulsed laser light PL becomes 1 ms or more, the heat affected layer damaged by the heat caused by the pulsed laser light PL in the fiber reinforced resin material 1 becomes large. Therefore, the pulse width of the pulsed laser light PL is preferably less than 1 ms.

[0082] On the other hand, if the peak output of the pulsed laser light PL exceeds 150 kW, a phenomenon known as air breakdown, in which the atmosphere turns into plasma, may occur depending on the processing environment. The plasma-like atmosphere absorbs and scatters the pulsed laser light PL, degrading the cutting quality. Therefore, while a shorter pulse width is preferable, setting the lower limit of the pulse width of the pulsed laser light PL to 1 μs makes it possible to cut without degrading the cutting quality.

[0083] In this embodiment, in addition to the irradiation of the pulsed laser beam PL, gas 123 is supplied from the side of the optical axis PLa through the nozzle 115, which serves as a side flow nozzle. This removes decomposition products 130 generated during laser processing from the processed portion on the optical axis PLa. Furthermore, when cutting the fiber reinforced resin material 1 with the laser processing apparatus 100, the direction of ejection of the decomposition products 130 tends to coincide with the optical axis PLa. Therefore, by employing a side flow nozzle, it is possible to prevent blind holes, which are holes in the middle of forming through holes, from obstructing the flow of the gas 123. As a result, it is possible to prevent a decrease in the processing speed of the fiber reinforced resin material 1 due to the decomposition products 130 remaining on the optical axis PLa.

[0084] As a result, the laser processing device 100 can prevent deterioration of the mechanical strength characteristics of the fiber reinforced resin material 1 after cutting and can efficiently cut the fiber reinforced resin material 1, enabling high-quality, efficient laser cutting of the fiber reinforced resin material 1 in a short time.

[0085] Furthermore, the type of gas 123 is not particularly limited since its purpose is to remove decomposition products 130, and gases such as nitrogen, helium, and oxygen can be used. The pressure of the gas 123 blown is preferably 0.1 MPa or higher. When the pressure of the gas 123 blown is 0.1 MPa or higher, the effect of removing decomposition products 130 is sufficient, and the processing quality can be sufficiently high.

[0086] The present invention has been described in detail above based on a preferred embodiment, but the present invention is not limited to this, and each component can be replaced with any component that can perform a similar function, or any component can be added.

[0087] For example, in the above-described embodiment, the laser oscillator oscillates a pulsed laser beam, but the present invention is not limited to this, and a laser oscillator that oscillates a continuous wave may also be used.

[0088] Furthermore, for example, in the above-described embodiment, a CO2 laser oscillator is used as the laser oscillator, but the present invention is not limited to this. For example, any of a gas laser oscillator other than a CO2 laser oscillator, a solid-state laser oscillator, and a liquid laser oscillator may be used. [Example]

[0089] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples.

[0090] Example 1 1. Production of nonwoven fiber web pieces and fiber web sheets First, recycled carbon fiber (fiber length: 50 mm) and polyamide fiber (fiber length: 51 cm, fineness: 6.6 dtex) as resin fiber were defibrated using an opener. Next, the defibrated recycled carbon fiber and polyamide fiber were mixed in a weight ratio of 34:49 to obtain a mixed fiber.

[0091] The mixed fibers were then fed into a wire carding machine to obtain a fiber web 35 cm wide. The obtained fiber web was then laminated while being wound up to obtain a laminated fiber web having a width of approximately 35 cm and a length of approximately 70 cm, in which multiple fiber webs were laminated.

[0092] Next, the laminated fiber web was placed in a needle punch machine, and the fibers in the laminated fiber web were entangled to obtain a first fiber web sheet 35 cm wide and 70 cm long. Two of these first fiber web sheets were stacked so that they intersected at angles of 0° and 90°, and placed in a double press belt machine. They were pressed together at 270°C and a pressure of 6 MPa for about 30 seconds while melting the nylon resin, and then cooled to obtain a laminated fiber web sheet. The laminated fiber web sheet was cut to a length of 24 cm and a width of 16 cm to fit the size of the mold, and used as a second fiber web sheet.

[0093] 2. Press molding A mold capable of producing a plate-shaped molded product was prepared and placed in a heat and cool press molding device. The mold measured 24 cm in length and 16 cm in width. A mating mold was placed over the mold containing the second fiber web sheet, closed, and heated to 270°C. Next, the mold placed on top was opened and closed several times by moving the mold up and down several times to degas the laminate.

[0094] Next, while maintaining the mold temperature at 270°C, a pressure of 10 MPa was applied to the mold surface and maintained for 180 seconds. The mold was then cooled to 90°C with water, and the molded product was removed from the mold to obtain a flat carbon fiber reinforced resin molded product measuring 24 cm in length, 16 cm in width, and 1.2 mm in thickness.

[0095] 3. Laser processing A carbon fiber reinforced resin molded product was set in a laser processing machine (ML1515CV-12XM, manufactured by Mitsubishi Electric Corporation) having the configuration shown in Figure 1, and laser processing was performed to obtain the outline shown in Figure 10, thereby obtaining a carbon fiber reinforced resin processed product according to the example.

[0096] The processing speed (set scanning speed) was 10 m / min. The processing length (circumferential length) during processing was 337.799 mm.

[0097] A photograph of the vicinity of the edge of the carbon fiber reinforced resin product according to the example is shown in Figure 11. As shown in Figure 11, no fraying of fibers or delamination was observed in the processed portion (edge) of the carbon fiber reinforced resin product according to the example.

[0098] (Comparative Example) A carbon fiber reinforced resin processed product according to a comparative example was obtained by laser processing in the same manner as in the example, except that the production of a carbon fiber reinforced resin molded product was omitted and a commercially available carbon fiber reinforced resin molded product was used instead of the carbon fiber reinforced resin molded product according to the example. The commercially available carbon fiber reinforced resin molded product used a carbon fiber woven fabric as the substrate and polyamide 6 as the resin. The commercially available carbon fiber reinforced resin molded product had a thickness of 1.0 mm.

[0099] A photograph of the vicinity of the edge of the carbon fiber reinforced resin product according to the comparative example is shown in Fig. 12. As shown in Fig. 12, fraying of the fibers and delamination were observed in the processed portion (edge) of the carbon fiber reinforced resin product according to the comparative example. [Explanation of symbols]

[0100] 1. Fiber-reinforced resin materials 10 Reinforcement fiber layer 11 Base material 13 Reinforcing Fiber 20 Resin (matrix resin) 100 Laser processing equipment 111 Laser oscillator 112 Light path 113 Processing head 114 Drive unit 115 nozzles 116 Nozzle movement mechanism 117 Detection unit 118 Control Unit

Claims

1. The method includes a step of removing a fiber reinforced resin material containing a plurality of reinforcing fibers and a resin by using a laser beam, The method for manufacturing a fiber-reinforced resin material processed product, wherein the reinforcing fibers in the fiber-reinforced resin material are entangled with other reinforcing fibers.

2. the laser beam is a pulsed laser beam, 2. The method for manufacturing a fiber-reinforced resin material processed product according to claim 1, wherein in the step, the removal processing is performed by irradiating the fiber-reinforced resin material with the pulsed laser light to form a plurality of through holes in the fiber-reinforced resin material, and each through hole is formed by irradiating the fiber-reinforced resin material with the pulsed laser light once.

3. The method for manufacturing a fiber-reinforced resin material processed product according to claim 1 , wherein the reinforcing fibers in the fiber-reinforced resin material are entangled with each other by needle punching.

4. The method for producing a fiber-reinforced resin material processed product according to claim 1 , wherein the fiber-reinforced resin material is molded using a needle-punched nonwoven fabric containing the reinforcing fibers as a reinforcing fiber substrate.

5. The method for producing a fiber-reinforced resin material processed product according to claim 1 , wherein the reinforcing fibers include recycled reinforcing fibers.

6. The method for manufacturing a fiber-reinforced resin material product according to claim 1 , wherein the reinforcing fibers include carbon fibers.

7. A laser processing device used in the method for manufacturing a fiber-reinforced resin material product according to any one of claims 1 to 6.

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