Laser cutting machine introduction
Laser cutting is to focus the laser light emitted from the laser into a high-power density laser beam through the optical path system. The laser beam irradiates the surface of the workpiece to make the workpiece reach the melting point or boiling point, and the high-pressure gas coaxial with the beam blows away the molten or vaporized metal. As the relative position of the beam and the workpiece moves, the material will eventually form a slit, so as to achieve the purpose of cutting.
Laser cutting processing is to replace the traditional mechanical knife with an invisible beam. It has the characteristics of high precision, fast cutting, not limited to the cutting pattern, automatic typesetting, saving material, smooth cutting, and low processing cost. It will gradually improve or replace it. Traditional metal cutting process equipment. The mechanical part of the laser cutter head has no contact with the work, and will not scratch the work surface during work; the laser cutting speed is fast, the incision is smooth and flat, and generally does not need subsequent processing; the cutting heat affected zone is small, the plate deformation is small, and the slit is narrow ( 0.1mm~0.3mm); The incision has no mechanical stress, no shearing burr; high processing accuracy, good repeatability, and no damage to the surface of the material; CNC programming, can process any plan, and can cut large-format whole plates without Opening the mold saves time and economy.
As a new type of tool, laser equipment is increasingly used in various industries, including laser cutting machines, laser engraving machines, laser marking machines, laser welding machines, etc.
As a new type of tool, laser cutting machine equipment is currently being used more and more maturely in various industries, including laser cutting machines, laser engraving machines, laser marking machines, laser welding machines, etc.
Features of laser cutting machine
1. 64MB high-capacity memory, fast transmission, and can work offline
2. Digital electronic control Z-axis adjustment, fully automatic focusing mode
3. Large workbench and built-in lighting
4. American original special air-cooled closed metal pipe
5. Red light module, CCD automatic positioning
6. Work platform with complete functions and easy to learn
7. Modular design, easy maintenance
8.U.S. metal laser radio frequency tube, with a lifespan of 45,000 hours
9. Upper air blowing and lower air exhaust system to ensure processing quality
10. Probe type auto focus, effectively guarantee the cutting depth
11. Open space, reserved expansion ports can easily add auxiliary automation equipment, very expandable
12. The product is mature and stable, highly integrated, and complete selection of accessories
13. Comply with CDRH Clas1 safety regulations, CE certification and RoSH certification
14. Ball screw drive
15. Servo drive system to ensure accuracy.
First, the energy of the laser is concentrated into a high-density beam in the form of light, and the beam is transmitted to the working surface to generate enough heat to melt the material. In addition, the high-pressure gas coaxial with the beam directly removes the molten metal, so as to achieve the purpose of cutting. This shows that laser cutting is essentially different from the machining of machine tools.
It uses the laser beam emitted from the laser generator to focus into a high-power density laser beam irradiation condition through the optical path system. The laser heat is absorbed by the workpiece material, and the temperature of the workpiece rises sharply. After reaching the boiling point, the material begins to vaporize and form holes. , Accompanied by the high-pressure airflow, as the relative position of the beam and the workpiece moves, the material will eventually form a slit. The process parameters (cutting speed, laser power, gas pressure, etc.) and motion trajectory during slitting are controlled by the numerical control system, and the slag at the slit is blown away by a certain pressure of auxiliary gas.
In the carbon dioxide laser cutting machine technology, carbon dioxide gas is the medium that generates the laser beam. However, fiber lasers are transmitted through diodes and fiber optic cables. The fiber laser system generates a laser beam through multiple diode pumps, and then transmits it to the laser cutting head through a flexible fiber optic cable instead of transmitting the beam through a mirror. This has many advantages, the first is the size of the cutting bed. Unlike the gas laser technology, the reflector must be set within a certain distance. Unlike fiber laser technology, there is no range limit. Moreover, the fiber laser can even be installed next to the plasma cutting head of the plasma cutting bed. There is no such option for CO2 laser cutting technology. Similarly, when compared with a gas cutting system of the same power, the system is more compact due to the ability of the fiber to bend.
Generally speaking, the quality of laser cutting can be measured by the following 6 standards.
1. Cutting surface roughness Rz
2. Cutting slag size
3. Cutting edge perpendicularity and slope u
4. Cutting edge round corner size r
5. Drag after stripes n
6. Flatness F
Laser is a kind of light, like other luminous bodies in nature, it is produced by the transition of atoms (molecules or ions, etc.), and it is caused by spontaneous radiation. Although the laser is light, it is obviously different from ordinary light in that the laser only relies on spontaneous emission for a very short period of time, and the subsequent process is completely determined by the excitation radiation, so the laser has a very pure color and almost no divergent directivity. , Very high luminous intensity. The laser also has high coherence, high intensity, and high directivity. After the laser is generated by the laser, it is transmitted by the reflecting mirror and irradiated on the processed object through the focusing mirror, so that the processed object (surface) is subjected to strong heat and the temperature increases sharply. The point is quickly melted or vaporized due to high temperature, and the operation track of the laser head is matched to achieve the purpose of processing. The application of laser processing technology in the advertising industry is mainly divided into two working methods: laser cutting and laser engraving. For each working method, we have some differences in the operation process.
It is mainly carried out on the surface of the object, which is divided into two types: bitmap carving and vector carving:
Bitmap engraving: We first carry out the screen processing of the graphics we need to engrave in PHOTOSHOP and convert them into monochrome BMP format, and then open the graphics file in the dedicated laser engraving and cutting software. According to the material we are processing, we can set the appropriate parameters, and then click Run, the laser engraving machine will engrave according to the dot matrix effect produced by the graphic file.
Vector engraving: use vector software such as Coreldraw, AutoCad, Illustrator and other typesetting design, and export the graphics to PLT, DXF, AI format, marking machine, and then use the special laser cutting and engraving software to open the graphic file and send it to laser engraving Processing in the machine.
In the advertising industry, it is mainly suitable for the processing of wood, two-color boards, plexiglass, colored paper and other materials.
We can understand it as the separation of edges. For such processing purposes, we should first make the graphics in the form of vector lines in CORELDRAW, AUTOCAD, pneumatic marking machine, and then save it in the corresponding PLT, DXF format, and open the file with the laser cutting machine operating software. According to our The processed material can be run after setting the parameters such as energy and speed. The laser cutting machine will automatically cut according to the flight path generated by the software after receiving instructions from the computer. For example, the existing laser cutting machine can draw a template according to the computer, and then directly input it into the computer to automatically cut the graphics. Existing laser cutting machines generally have their own hard disk, which can input massive data sources.
Laser melting and cutting
In laser melting and cutting, the workpiece is partially melted and the molten material is sprayed out with the help of airflow. Because the transfer of the material only occurs in its liquid state, the process is called laser melting and cutting.
The laser beam is matched with a high-purity inert cutting gas to drive the melted material away from the slit, and the gas itself does not participate in the cutting. Laser melting cutting can get a higher cutting speed than gasification cutting. The energy required for gasification is usually higher than the energy required to melt the material. In laser melting and cutting, the laser beam is only partially absorbed. The maximum cutting speed increases with the increase of the laser power, and decreases almost inversely with the increase of the thickness of the sheet and the increase of the melting temperature of the material. In the case of a certain laser power, the limiting factor is the air pressure at the slit and the thermal conductivity of the material. Laser melting and cutting can obtain oxidation-free incisions for iron materials and titanium metals. The laser power density that produces melting but not gasification is between 104 W/cm2 and 105 W/cm2 for steel materials.
Laser flame cutting
The difference between laser flame cutting and laser melting cutting is that oxygen is used as the cutting gas. With the help of the interaction between oxygen and the heated metal, a chemical reaction is generated to further heat the material. Due to this effect, for structural steel of the same thickness, the cutting rate that can be obtained by this method is higher than that of melting cutting.
On the other hand, this method may have worse cut quality compared to fusion cutting. In fact, it will produce wider kerf, obvious roughness, increased heat-affected zone and worse edge quality. Laser flame cutting is not good when processing precision models and sharp corners (there is a danger of burning off the sharp corners). A pulsed laser can be used to limit the thermal influence, and the power of the laser determines the cutting speed. In the case of a certain laser power, the limiting factor is the supply of oxygen and the thermal conductivity of the material.
Laser gasification cutting
In the process of laser gasification and cutting, the material gasifies at the kerf. In this case, very high laser power is required.
In order to prevent material vapor from condensing on the slit wall, the thickness of the material must not greatly exceed the diameter of the laser beam. This process is therefore only suitable for applications where the removal of molten material must be avoided. This processing is actually only used in areas where iron-based alloys are very small.
This process cannot be used for materials such as wood and certain ceramics that are not in a molten state and therefore are unlikely to allow the material vapor to recondense. In addition, these materials usually require thicker cuts. In laser gasification cutting, the optimal beam focus depends on the material thickness and beam quality. The laser power and the heat of vaporization have only a certain influence on the optimal focus position. In the case of a certain thickness of the sheet, the maximum cutting speed is inversely proportional to the vaporization temperature of the material. The required laser power density is greater than 108W/cm2 and depends on the material, cutting depth and beam focus position. In the case of a certain sheet thickness, assuming sufficient laser power, the maximum cutting speed is limited by the gas jet speed.
The laser cutting machine is a technological revolution in sheet metal processing, and it is the 'processing center' in sheet metal processing. The laser cutting machine has high flexibility, fast cutting speed, high production efficiency, and short product production cycle. It has won a wide range of customers In the market, this technology has a long effective lifespan. Most foreign plates with a thickness of more than 2 mm use laser cutting machines. Many foreign experts agree that the next 30-40 years will be the golden period for the development of laser processing technology.
Generally speaking, it is recommended to use a laser cutting machine for cutting metal materials such as carbon steel plates within 12mm and stainless steel plates within 10mm. The laser cutting machine has no cutting force, no deformation in processing: no tool wear, good material adaptability: no matter it is simple or complex parts, it can be cut with precision and rapid prototyping at one time: its slit is narrow, the cutting quality is good, and the degree of automation is high. Easy to operate, low labor intensity, no pollution: It can realize automatic cutting and nesting, improve the utilization rate of materials, low production costs, and good economic benefits.
There are many factors to consider when choosing a laser cutting machine. In addition to considering the maximum size of the workpiece, the material, the maximum thickness to be cut, and the size of the raw material format, more considerations need to be given to the future development direction, such as the product The size of the largest workpiece to be processed after the technical transformation, the breadth of the material provided by the steel market, which is the most economical for its products, and the loading and unloading time.