Laser cutting process and apparatus for composite materials

Abstract

The application relates to the technical field of industrial material cutting, in particular to a laser cutting process method and equipment for composite materials, which comprises the following steps: running cutting software in a cutting equipment, and importing a cutting file into the cutting software; placing a composite material to be cut on a workbench of the cutting equipment; and cutting the composite material to be cut in a non-contact manner by using a laser on the workbench based on the cutting file. Since the laser is used to cut the composite material to be cut in a non-contact manner according to the method, compared with a traditional composite material cutting method, the laser cutting process method for the composite material provided by the application has small heat influence on the cut composite material, and the cut composite material has no burr on the edge, so that the deformation and poor precision of the composite material caused by the traditional physical contact (such as using a cutter wheel, a grinding wheel and the like) cutting method are avoided, and the quality of the cut composite material is improved.

Description

Technical Field

[0001] This invention relates to the field of material cutting technology, and in particular to a laser cutting process and equipment for composite materials. Background Technology

[0002] Multilayer composite optical sheets are a type of multilayer composite lens material, developed as a process technology to further enhance brightness based on optical brightening sheets. Compared to the brightness enhancement method of traditional prism films, multilayer optical sheets enhance brightness without affecting the viewing angle, and are therefore widely used in large-size products such as LCDs and TVs that have high brightness requirements. However, with the increasing demands of users, the shape requirements for multilayer composite optical sheets (such as irregular polygons, perforated polygons, etc.) are becoming increasingly diverse. Therefore, how to cut multilayer composite optical sheets to meet specific needs has become a key research focus in the industry.

[0003] Traditionally, multilayer composite optical sheets are cut using consumables such as cutting wheels and grinding wheels. However, since multilayer composite optical sheets are based on a resin-based citric acid polymer (with PET film covering both the top and bottom layers), the melting points and heat distortion temperatures of each layer differ significantly. This results in insufficient processing precision and a high number of defective products when using the traditional method.

[0004] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0005] The main objective of this invention is to provide a laser cutting process and equipment for composite materials, which aims to solve the technical problems of insufficient processing accuracy and high defect rate of multilayer composite optical sheets processed by traditional cutting processes.

[0006] To achieve the above objectives, the present invention provides a laser cutting process for composite materials, the method comprising the following steps:

[0007] Run the cutting software in the cutting equipment, and import the cutting drawing file through the cutting software;

[0008] Place the composite material to be cut on the worktable of the cutting equipment;

[0009] Based on the cutting pattern, the composite material to be cut is cut in a non-contact manner using a laser on the worktable.

[0010] Optionally, before the step of running the cutting software in the cutting device and importing the cutting drawing file through the cutting software, the method further includes:

[0011] Turn on the main power switch, chiller switch, laser switch, industrial computer switch, and electrical control box switch of the cutting equipment in sequence to start the cutting equipment;

[0012] Confirm whether the cutting equipment has been started, and when the cutting equipment has been started, execute the steps of running the cutting software in the cutting equipment and importing the cutting drawing file through the cutting software.

[0013] Optionally, the step of placing the composite material to be cut on the worktable of the cutting equipment includes:

[0014] The light reflectance of the front side of the composite material to be cut is compared with that of the back side to obtain the comparison results;

[0015] The target placement method of the composite material to be cut is determined based on the comparison results.

[0016] The composite material to be cut is placed on the worktable of the cutting equipment based on the target placement method.

[0017] Optionally, the step of determining the target placement method of the composite material to be cut based on the comparison result includes:

[0018] If the light reflectance of the front side is greater than that of the back side, then the placement method with the back side up and the front side down will be the target placement method.

[0019] Optionally, determining the target setting method for the composite material to be cut based on the comparison result further includes:

[0020] If the light reflectance corresponding to the front side is less than or equal to the light reflectance corresponding to the back side, then the placement method with the back side down and the front side up is taken as the target placement method.

[0021] Optionally, the step of cutting the composite material to be cut using a laser on the worktable in a non-contact manner based on the cutting pattern includes:

[0022] The cutting software converts the cutting drawing into a laser path diagram, which is used to indicate the propagation path of the laser emitted by the laser in the cutting equipment.

[0023] The laser is controlled according to the laser path diagram to cut the composite material to be cut in a non-contact manner.

[0024] Optionally, the step of controlling the laser to cut the composite material to be cut in a non-contact manner according to the laser path diagram includes:

[0025] The laser is controlled according to the laser path diagram, and the beam diameter and diffusion angle of the laser emitted by the laser are changed by the beam expander so that the laser propagates into the galvanometer.

[0026] The laser is controlled to move in the X and Y directions by the galvanometer, and the laser is focused by the field lens;

[0027] The composite material to be cut is cut in a non-contact manner using a focused laser following the movement direction controlled by the galvanometer.

[0028] Optionally, the applicable wavelength of the beam expander is 355nm, the light-gathering aperture of the galvanometer is 10mm, the applicable wavelength is 355nm, and the scanning speed is less than 10000mm / s, and the applicable wavelength of the field lens is 355nm and the focal length is 100mm.

[0029] Optionally, the laser is an ultraviolet picosecond laser;

[0030] The ultraviolet picosecond laser has a power of 2.5W and a frequency of 100kHz.

[0031] The ultraviolet picosecond laser emits a laser with a wavelength of 355nm, a pulse width of 6-15ps, and a speed of 500mm / s.

[0032] In addition, the present invention also provides a laser cutting process equipment for composite materials, the laser cutting process equipment for composite materials including: a laser, a beam expander, a galvanometer, a field lens and a worktable;

[0033] The laser emitting end of the laser is directed toward the incident end of the beam expander, the emitting end of the beam expander is directed toward the incident end of the galvanometer, the emitting end of the galvanometer is directed toward the incident end of the field lens, and the emitting end of the field lens is directed toward the worktable.

[0034] This invention involves running cutting software in a cutting device and importing a cutting drawing file through the software. The composite material to be cut is placed on the worktable of the cutting device. Based on the cutting drawing file, a laser on the worktable is used to cut the composite material in a non-contact manner. Because this invention uses a laser to cut the composite material in a non-contact manner, compared to traditional composite material cutting methods, the laser cutting process provided by this invention results in less heat-affected zone and burr-free edges on the cut composite material. This avoids the deformation and poor precision caused by traditional physical contact cutting methods (such as using cutting wheels or grinding wheels), thereby improving the quality of the cut composite material. Attached Figure Description

[0035] Figure 1This is a schematic flowchart of the first embodiment of the laser cutting process for composite materials of the present invention;

[0036] Figure 2 This is a schematic flowchart of the second embodiment of the laser cutting process method for composite materials of the present invention;

[0037] Figure 3 This is a schematic flowchart of the third embodiment of the laser cutting process for composite materials of the present invention;

[0038] Figure 4 This is a schematic diagram of the structure of the laser cutting equipment for the composite material of the present invention.

[0039] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0040] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0041] This invention provides a laser cutting process for composite materials, with reference to... Figure 1 , Figure 1 This is a schematic flowchart of the first embodiment of the laser cutting process for composite materials of the present invention.

[0042] In this embodiment, the laser cutting process for the composite material includes the following steps:

[0043] Step S10: Run the cutting software in the cutting equipment and import the cutting drawing file through the cutting software.

[0044] It should be noted that the aforementioned cutting equipment may include accessories such as lasers, beam expanders, galvanometers, field lenses, and worktables.

[0045] It should be understood that the format of the above-mentioned cut drawing file can be any of DXF, DWG, or PLT, and this embodiment does not limit it.

[0046] It is understood that the cutting software is a preset software built into the cutting equipment. The cutting software can be used to set relevant parameters of the cutting equipment, such as the wavelength of the laser, the magnification of the beam expander, and the focal length of the field lens, so that the cutting equipment can cut the composite material to be cut according to the predetermined parameters.

[0047] Step S20: Place the composite material to be cut on the worktable of the cutting equipment.

[0048] It should be noted that the aforementioned composite material to be cut is a multilayer composite lens material, which can be composed of a resin substrate, a citric acid ester polymer, and a PET film (polyester film). Specifically, the citric acid ester polymer can be tributyl citrate or acetylated tributyl citrate. The composite material to be cut can be divided into four layers: the first layer can be a 50µm PET film, the second layer can be a 15µm citric acid ester polymer, the third layer can be a 20µm resin substrate, and the fourth layer can be a 50µm PET film. Of course, the above description of the composition of the composite material to be cut is for illustrative purposes only and not for limitation. Other composite materials with similar compositions are also applicable to this embodiment, and will not be elaborated upon here.

[0049] It should be understood that the aforementioned workbench is a platform that can maintain the composite material to be cut in a horizontal state during the working process. The material of the workbench can be marble or any other material that can be used as a cutting platform for multi-layer composite lens materials, such as stainless steel, aluminum alloy, etc. This embodiment does not limit this.

[0050] In practice, since the composite material to be cut is often used in large-size LCD and TV products, it may be quite heavy. In this case, the composite material to be cut can be placed on the worktable of the cutting equipment by using mechanized equipment (such as fully automatic robotic arms or semi-automatic fixtures).

[0051] Step S30: Based on the cutting drawing, use the laser on the worktable to cut the composite material to be cut in a non-contact manner.

[0052] It should be noted that due to the material properties of the composite material to be cut (i.e., the melting points and heat distortion temperatures of each layer are significantly different), using traditional contact cutting methods (such as using consumables like cutting wheels or grinding wheels) would cause deformation of the composite material, resulting in low precision and a high number of defective products after cutting. Therefore, in this embodiment, a laser can be used to cut the composite material in a non-contact manner.

[0053] In practical implementation, the process of cutting the composite material using the laser emitted by the aforementioned laser can be divided into: material thermal absorption, material heating, material surface melting and vaporization, and cooling and solidification. Laser processing and cutting is essentially the interaction between the laser and the composite material to be cut. When the laser beam is projected onto the surface (or interior) of the composite material, some energy is reflected, some is absorbed, and some is transferred. Light energy is absorbed in the form of vibrational excitation of electrons and atoms, resulting in energy transfer and transmission. This energy transfer and transmission causes various physical, chemical, and biological effects and processes. The optical effects of lasers mainly fall into two categories: photochemical reactions and photothermal effects. In this embodiment, laser cutting actually utilizes the photothermal effect of the laser.

[0054] In this embodiment, cutting software is run in the cutting equipment, and a cutting drawing is imported through the software. The composite material to be cut is placed on the worktable of the cutting equipment. Based on the cutting drawing, a laser on the worktable is used to cut the composite material in a non-contact manner. Because the method described in this embodiment uses a laser to cut the composite material in a non-contact manner, compared to traditional composite material cutting methods, the laser cutting process for composite materials provided by this invention results in less heat-affected zone and burr-free edges after cutting. This avoids the deformation and poor precision of the composite material caused by traditional physical contact cutting methods (such as using cutting wheels, grinding wheels, etc.), thereby improving the quality of the cut composite material.

[0055] refer to Figure 2 , Figure 2 This is a schematic flowchart of the second embodiment of the laser cutting process for composite materials of the present invention.

[0056] Furthermore, to ensure that the cutting equipment starts cutting under normal operating conditions, thereby avoiding product scrap due to the use of abnormal equipment, the following steps may be included before step S10:

[0057] Step S01: Turn on the main switch of the cutting equipment, the chiller switch, the laser switch, the industrial control computer switch, and the electrical control box switch in sequence to start the cutting equipment.

[0058] It should be noted that the above-mentioned chiller switch is used to control the opening or closing of the chiller equipment. The chiller equipment is a cooling water device that can provide constant temperature, constant flow and constant pressure. The chiller equipment can be a screw chiller unit, a scroll chiller unit or a centrifugal chiller unit. This embodiment does not limit it.

[0059] Step S02: Confirm whether the cutting equipment has been started, and when the cutting equipment has been started, execute the step of running the cutting software in the cutting equipment and importing the cutting drawing file through the cutting software.

[0060] It should be understood that the status of the cutting equipment's startup can be confirmed based on its indicator lights. For example, the colors of the indicator lights can be predefined, such as green representing startup completion and red representing incomplete startup. In actual production, when the indicator light is green, the steps of running the cutting software on the cutting equipment and importing the cutting drawing file through the software can be executed. Of course, the above description of preset colors is for illustrative purposes only and is not intended to limit the scope. Other preset colors that can distinguish whether the cutting equipment has started up are also applicable to this embodiment, and will not be elaborated here.

[0061] Furthermore, in order to reduce the thermal impact of the composite material being cut during the cutting process, in this embodiment, step S20 may include:

[0062] Step S201: Compare the light reflectance of the front side of the composite material to be cut with the light reflectance of the back side to obtain the comparison result.

[0063] It should be noted that the above-mentioned light reflectance can be the ratio of the luminous flux of the reflected light to the luminous flux of the incident light.

[0064] In practice, the light reflectance of the front and back sides of the composite material to be cut can be detected by photoelectric measurement.

[0065] Step S202: Determine the target placement method of the composite material to be cut based on the comparison results.

[0066] It should be noted that the above target placement method refers to whether the composite material to be cut is facing up (i.e., facing the laser's light inlet) or facing down (i.e., facing the laser's light inlet).

[0067] Step S203: Place the composite material to be cut on the worktable of the cutting equipment based on the target placement method.

[0068] Furthermore, in order to determine the placement method based on the material properties of the composite material to be cut, thereby reducing the thermal impact of laser cutting on the composite material to be cut, in this embodiment, step S202 may include:

[0069] Step S2021: If the light reflectance of the front side is greater than that of the back side, then the placement method with the back side up and the front side down is taken as the target placement method.

[0070] It should be understood that for the aforementioned composite material to be cut, the greater the light reflectivity of the surface in contact with the laser, the greater the heat-affected zone (HAZ); and the greater the HAZ, the lower the precision of the cut composite material. Therefore, if the light reflectivity of the front side of the composite material is greater than that of the back side, the composite material can be placed on the worktable of the cutting equipment with the back side facing up and the front side facing down, thereby reducing the HAZ during laser cutting.

[0071] Step S2022: If the light reflectance corresponding to the front side is less than or equal to the light reflectance corresponding to the back side, then the placement method with the back side down and the front side up is taken as the target placement method.

[0072] Understandably, based on the discussion in step S2021 above, if the light reflectance of the front side of the composite material to be cut is less than or equal to the light reflectance of the back side, the composite material to be cut can be placed on the worktable of the cutting equipment with the front side facing up and the back side facing down, thereby reducing the heat impact during the laser cutting process.

[0073] This embodiment starts the cutting equipment by sequentially turning on the main power switch, chiller switch, laser switch, industrial computer switch, and electrical control box switch. It then confirms that the cutting equipment has started successfully and, upon successful startup, executes the steps of running the cutting software within the equipment and importing the cutting drawing file. The reflectivity of the front and back sides of the composite material to be cut is compared. If the reflectivity of the front side is greater than that of the back side, the placement with the back side up and the front side down is chosen as the target placement. If the reflectivity of the front side is less than or equal to that of the back side, the placement with the back side down and the front side up is chosen as the target placement. Based on the target placement, the composite material to be cut is placed on the worktable of the cutting equipment. Because this embodiment determines that the side with lower reflectivity faces upwards (i.e., towards the laser inlet) during the cutting process based on the reflectivity of the front and back sides of the composite material, compared to existing composite material cutting methods, this method can reduce the negative impact of reflected light on the cutting effect, thereby reducing the thermal impact of the composite material during laser cutting and improving cutting accuracy.

[0074] refer to Figure 3 , Figure 3 This is a schematic flowchart of the third embodiment of the laser cutting process for composite materials of the present invention.

[0075] In order to accurately control the laser, in this embodiment, step S30 above may include:

[0076] Step S301: The cutting drawing is converted into a laser path diagram by the cutting software. The laser path diagram is used to indicate the propagation path of the laser emitted by the laser in the cutting device.

[0077] It should be noted that the aforementioned laser can be an ultraviolet picosecond laser. Specifically, the power of the ultraviolet picosecond laser can be 2.5W, and the frequency can be 100kHz. The wavelength of the laser emitted by the aforementioned ultraviolet picosecond laser can be 355nm, the pulse width can be 6-15ps, and the velocity can be 500mm / s.

[0078] Step S302: Control the laser to cut the composite material to be cut in a non-contact manner according to the laser path diagram.

[0079] In practice, the surface corresponding to the cutting pattern can be decomposed into several points of the same size as the laser spot. Then, the cutting software can be used to optimally connect these points, and the path corresponding to this connection is the laser path diagram. This allows the cutting equipment to control the laser to cut the composite material in a non-contact manner according to the laser path diagram.

[0080] Furthermore, in order to improve the cutting accuracy of laser cutting, in this embodiment, step 302 above may include:

[0081] Step S3021: Control the laser according to the laser path diagram, and change the beam diameter and diffusion angle of the laser emitted by the laser through the beam expander so that the laser propagates into the galvanometer.

[0082] It is understood that the laser beam diameter mentioned above is the diameter along a specified line perpendicular to and intersecting the laser beam axis; the laser diffusion angle mentioned above is the angle between the center and the boundary of the effective illumination area of ​​the laser. The applicable wavelength of the beam expander mentioned above is 355nm, and the magnification is 2-10 times.

[0083] Step S3022: Control the movement of the laser in the X and Y directions using the galvanometer, and focus the laser using a field lens.

[0084] It should be noted that the aforementioned galvanometer, also known as the scanning head, contains two motors with reflectors to control the movement of the laser in the X and Y directions, thereby enabling the processing of complex patterns. The galvanometer has an aperture of 10mm, an applicable wavelength of 355nm, and a scanning speed of less than 10000mm / s.

[0085] Understandably, the applicable wavelength for the above field lens is 355nm and the focal length is 100mm.

[0086] Step S3023: Use the focused laser to cut the composite material to be cut in a non-contact manner according to the moving direction controlled by the galvanometer.

[0087] This embodiment converts the cutting drawing into a laser path diagram using cutting software. The laser path diagram indicates the propagation path of the laser emitted by the laser in the cutting equipment. The laser is controlled according to the laser path diagram, and the beam diameter and diffusion angle of the emitted laser are changed by a beam expander to ensure the laser propagates into the galvanometer. The galvanometer controls the movement of the laser in the X and Y directions, and a field lens focuses the laser. The focused laser is then used to cut the composite material to be cut in a non-contact manner according to the movement direction controlled by the galvanometer. Because this embodiment uses a laser to cut the composite material in a non-contact manner, compared to traditional composite material cutting methods, the laser cutting process for composite materials provided by this invention results in less heat-affected zone and burr-free edges after cutting. This avoids the deformation and poor precision of the composite material caused by traditional physical contact cutting methods (such as using cutting wheels or grinding wheels), thereby improving the quality of the cut composite material.

[0088] In addition, such as Figure 4 As shown, Figure 4 This is a schematic diagram of the cutting device of the present invention.

[0089] This invention also proposes a laser cutting process apparatus for composite materials, which can be applied to the laser cutting process method for composite materials described above. The laser cutting process apparatus for composite materials includes: a laser, a beam expander, a galvanometer, a field lens, and a worktable; wherein the laser emitting end of the laser faces the incident end of the beam expander, the emitting end of the beam expander faces the incident end of the galvanometer, the emitting end of the galvanometer faces the incident end of the field lens, and the emitting end of the field lens faces the worktable.

[0090] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0091] The sequence numbers of the above embodiments of the present invention are merely for description and do not represent the superiority or inferiority of the embodiments. Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0092] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A laser cutting process for composite materials, characterized in that, The method includes the following steps: Run the cutting software in the cutting equipment, and import the cutting drawing file through the cutting software; Place the composite material to be cut on the worktable of the cutting equipment; Based on the cutting pattern, the composite material to be cut is cut in a non-contact manner using a laser on the worktable; The first layer of the composite material to be cut is a 50µm PET film, the second layer is a 15µm citric acid ester polymer, the third layer is a 20µm resin substrate, and the fourth layer is a 50µm PET film. The laser is an ultraviolet picosecond laser with a power of 2.5W and a frequency of 100kHz. The wavelength of the laser emitted by the ultraviolet picosecond laser is 355nm, the pulse width is 6-15ps, and the speed is 500mm / s. The step of placing the composite material to be cut on the worktable of the cutting equipment includes: The light reflectance of the front side of the composite material to be cut is compared with that of the back side to obtain the comparison results; If the light reflectance of the front side is greater than that of the back side, then the placement method with the back side up and the front side down will be the target placement method. If the light reflectance corresponding to the front side is less than or equal to the light reflectance corresponding to the back side, then the placement method with the back side down and the front side up is taken as the target placement method. The composite material to be cut is placed on the worktable of the cutting equipment based on the target placement method.

2. The laser cutting process method for composite materials as described in claim 1, characterized in that, Before the step of running the cutting software in the cutting equipment and importing the cutting drawing file through the cutting software, the method further includes: Turn on the main power switch, chiller switch, laser switch, industrial computer switch, and electrical control box switch of the cutting equipment in sequence to start the cutting equipment; Confirm whether the cutting equipment has been started, and when the cutting equipment has been started, execute the steps of running the cutting software in the cutting equipment and importing the cutting drawing file through the cutting software.

3. The laser cutting process method for composite materials as described in claim 1, characterized in that, The step of cutting the composite material to be cut using a laser on the worktable in a non-contact manner based on the cutting pattern includes: The cutting software converts the cutting drawing into a laser path diagram, which is used to indicate the propagation path of the laser emitted by the laser in the cutting equipment. The laser is controlled according to the laser path diagram to cut the composite material to be cut in a non-contact manner.

4. The laser cutting process method for composite materials as described in claim 3, characterized in that, The step of controlling the laser to cut the composite material to be cut in a non-contact manner according to the laser path diagram includes: The laser is controlled according to the laser path diagram, and the beam diameter and diffusion angle of the laser emitted by the laser are changed by the beam expander so that the laser propagates into the galvanometer. The laser is controlled to move in the X and Y directions by the galvanometer, and the laser is focused by the field lens; The composite material to be cut is cut in a non-contact manner using a focused laser following the movement direction controlled by the galvanometer.

5. The laser cutting process method for composite materials as described in claim 4, characterized in that, The beam expander has an applicable wavelength of 355nm, the galvanometer has an aperture of 10mm, an applicable wavelength of 355nm, and a scanning speed of less than 10000mm / s, and the field lens has an applicable wavelength of 355nm and a focal length of 100mm.

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