EN
In the modern manufacturing arena, laser cutting technology has occupied a pivotal position, with its high efficiency, precision and many other advantages, widely used in aerospace, electronics, machinery and many other fields. In the many characteristics of laser cutting, precision is undoubtedly a key element of concern, the following we will discuss the precision of laser cutting related issues.
In laser cutting, different types of lasers have a significant impact on cutting accuracy. Common types of lasers include CO2 lasers, fiber lasers and crystal lasers. Fiber lasers, for example, are able to achieve a tighter focus and demonstrate a higher level of accuracy, especially when cutting thin materials. In contrast, different types of lasers have their own unique optical properties and energy distribution, which can lead to different precision results for the same cutting task.
Laser power is a key variable that affects accuracy. Generally speaking, higher power lasers have more cutting power and can be used to cut thicker materials, but this is often at the expense of a certain degree of accuracy. This is because the energy distribution and effect of the laser beam can become difficult to finely control at high power. On the contrary, lower power lasers, although limited in their ability to cut thick materials, are able to better ensure accuracy when cutting thin materials, resulting in neater cutting edges and more precise dimensions. Therefore, in practical application, according to the specific material thickness and precision requirements, the choice of laser power should be reasonably weighed to find a balance between precision and cutting ability.
The thickness of the material is not a small challenge to the laser cutting accuracy. When cutting thicker materials, the laser beam in the process of penetrating the material, with the increase in propagation distance, there will be a certain degree of diffusion phenomenon, which leads to the cutting edge of the precision is difficult to maintain at a high level, prone to cutting surface is not flat enough, dimensional deviations and other issues. As for thin materials relatively speaking, the laser beam can act more accurately, which is more conducive to the realization of high-precision cutting effect.
Different materials have different characteristics, which have different effects on laser cutting accuracy. Among metals, stainless steel has high hardness, good cutting detail accuracy, and dimensional accuracy of ±0.002 – ±0.005 inches, which is commonly used in high-precision manufacturing. Aluminum is soft, high reflectivity, cutting accuracy of about ±0.003 – ±0.006 inches, mostly used in aerospace, automotive parts field.
Plastic materials, acrylic cuts with smooth edges and accuracy of ±0.004 inches, suitable for signage and other manufacturing. Polycarbonate is prone to discoloration and burrs, and accuracy fluctuates from ±0.005 – ±0.010 inches, depending on the situation. In wood, hardwoods are accurate to about ±0.005 inches, and softwoods are affected by a variety of factors, with accuracy ranging from ±0.005 – ±0.010 inches. Glass and ceramics are more difficult to cut, with accuracies of about ±0.007 inches and ±0.006 inches, respectively, each corresponding to application scenarios.
Cutting speed plays a critical role in laser cutting accuracy. If the cutting speed is too fast, the laser will not have enough time to act on the material in each design element, and will not be able to provide enough energy, resulting in a cut pattern that may be incomplete, or the depth of cut is not up to the required level, which affects the final precision results. On the contrary, if the cutting speed is too slow, the laser stays on the material for too long, which will cause excessive heat accumulation, which may not only damage the workpiece, but also greatly reduce the precision of processing. Therefore, in actual operation, it is necessary to determine the appropriate cutting speed through repeated tests to guarantee the cutting accuracy.
High-quality laser cutting machine and regular maintenance is an important guarantee to ensure that the cutting accuracy is always stable. A machine with good performance, the manufacturing precision and assembly precision of its internal components are higher, which can provide a more stable working environment for laser cutting. If some key components of the machine are worn out, or there is a deviation in the alignment of the machine as a whole, then in the laser cutting process, it will have a serious negative impact on the accuracy, resulting in cutting out the workpiece does not meet the accuracy requirements.
Environmental factors should not be ignored, such as environmental temperature, humidity, etc., will have an impact on the laser cutting machine and the material to be cut. For example, too high or too low temperature may change the laser energy transmission characteristics, humidity changes may affect the physical properties of the material, which in turn affects the cutting accuracy. Therefore, maintaining a relatively stable and suitable cutting environment is necessary to realize high-precision laser cutting.
Operator experience and expertise also play a key role in controlling the accuracy of laser cutting. Skilled operators are able to accurately adjust the cutting parameters according to the material, machine status and other factors, and find and solve some minor problems in the cutting process in time, so as to maximize the guarantee of cutting accuracy. While inexperienced operators may be due to improper parameter settings, operation is not standardized and other reasons, resulting in cutting accuracy greatly reduced.
Compared with the traditional sheet metal cutting technology, laser cutting is undoubtedly an efficient, safe and highly accurate processing method. In the laser cutting process, through the precise control of the computer operation program, the cutting of materials can be controlled within an acceptable high precision range. Laser cutting technology can even be combined with CAD software to achieve precision cutting under the guidance of the software. In general, laser cutting can be focused to an accuracy of about 25 microns, which is about a quarter of the width of a strand of human hair, and the width of the slit can be as small as less than 0.001 inches, and the dimensional accuracy is usually about ±0.0005 inches, which demonstrates the advantages of the high precision of laser cutting.
Laser cutting tolerance refers to the maximum permissible deviation between the actual measured value of the cut part and the original design, which directly determines the accuracy of the part, and plays a crucial role in determining whether the cut part can be assembled with other parts smoothly.
Tolerances can be subdivided into dimensional and geometric tolerances. Dimensional tolerances reflect the allowable range of variation in the size of the part, for example, a hole designed to be 10mm wide, the dimensional tolerance may be set to ±0.1mm, which means that the actual width of the hole machined out between 9.9mm and 10.1mm are in line with the requirements. Geometric tolerances are mainly concerned with the shape, orientation and positional accuracy of each feature, such as flatness, roundness, parallelism, etc. They are all covered by geometric tolerances.
In the manufacturing industry, general manufacturing tolerances usually follow some established standards, for example, ISO 2768 is such a common standard, which provides a standardized guideline for the setting of dimensional tolerances in technical drawings, to ensure that the dimensional accuracy of the product can be maintained in different manufacturing methods, and that good coordination and universality can be achieved between various components.
Stainless Steel: Stainless steel has excellent performance in the field of laser cutting, by virtue of its hardness advantage, under the action of the laser beam, it can accurately present a variety of complex design shapes, and maintain a high level of detail accuracy. As mentioned above, its dimensional accuracy ranges from ±0.002 inches to ±0.005 inches, which makes stainless steel one of the preferred materials in many industrial applications, especially in the manufacture of precision parts that require high accuracy, such as the core components of some high-end machinery and the housings of precision instruments.
Aluminum：Although aluminum is a relatively soft metal, it has a wide range of applications in the aerospace and automotive industries due to its lightweight properties. However, due to the high reflectivity of aluminum, careful adjustment and precise control of the laser parameters by the operator is required during laser cutting to ensure cutting accuracy. Typically, the accuracy of laser cutting of aluminum materials is about ±0.003 inches to ±0.006 inches, through a reasonable cutting process, can still meet the relevant parts for the accuracy requirements.
Acrylic：Acrylic material in the laser cutting to show unique advantages, after cutting the edges show a smooth and flame-polished effect, visually very beautiful, and its accuracy can be controlled at ± 0.004 inches or so. It is based on such precision and appearance advantages, acrylic in the sign making, display rack manufacturing and other fields are very widely used, such as shopping malls display signs, store signs, etc., most of them will choose the acrylic material through the laser cutting to produce, in order to achieve both beautiful and accurate results.
Polycarbonate：Polycarbonate is a versatile plastic, but in the laser cutting process, it is prone to some problems such as discoloration, burrs, etc., which will have a certain impact on its accuracy. Its dimensional accuracy will vary according to the thickness of the material itself and the specific settings of the laser cutting, roughly in the range of ±0.005 inches to ±0.010 inches, in the actual application, according to the specific accuracy requirements and product characteristics, careful choice of whether to use polycarbonate and the corresponding laser cutting parameters.
Hardwoods (e.g. oak, maple)：Hardwoods, like oak and maple, have better consistency in laser cutting, thanks to their relatively tight wood structure and more uniform density. Generally speaking, their laser cutting accuracy can be maintained at around ±0.005 inches, so these hardwoods are often prioritized for laser cutting to create exquisite shapes in woodworking applications that require a high level of attention to detail, such as beautifully carved wood crafts and decorative components for high-end wood furniture.
Softwoods (e.g. pine)：Softwoods such as pine, due to its relatively low density and loose wood structure, the accuracy of laser cutting is affected by a number of factors, such as the moisture content of the wood, the direction of the wood grain, etc. will make its accuracy fluctuations. Typically, its accuracy range is about ± 0.005 inches to ± 0.010 inches between, so in the use of softwood for laser cutting, you need to pay more attention to the pretreatment of the material as well as the cutting parameters of the adjustment, in order to try to protect the cutting accuracy.
Glass：The brittleness of glass makes it a greater challenge in the laser cutting process, in order to avoid cracking and other problems in the cutting of glass, it is often necessary to use low power, high speed cutting, but this cutting method will also have a certain impact on the accuracy of the accuracy of about ± 0.007 inches or so. Nevertheless, glass by virtue of its transparent, beautiful and other characteristics, in some decorative applications, such as glass crafts, decorative glass partitions, etc., will still use laser cutting technology to achieve a unique shape design.
Ceramics：Ceramics is also a difficult material to cut, because it is easy to fracture, in the laser cutting needs to be extraordinarily careful control of the cutting process to ensure that the parameters of the precise settings. With this in mind, ceramics can be cut with an accuracy of around ±0.006 inches, which makes them irreplaceable for specific specialized industrial applications, such as electronic ceramic components and specialty ceramic products.
Many people have the misconception that all laser cutting machines are the same in terms of accuracy. But in fact, different types (such as CO2, fiber, crystal, etc.) of laser cutting machine, its own design features, laser generation and transmission of the way there are differences, coupled with the power settings and other factors, will lead to their respective advantages and disadvantages in cutting accuracy. For example, fiber laser cutting machines are more accurate in cutting certain thin materials, while CO2 laser cutting machines may be unique in their handling of specific materials, so it is not possible to generalize that all laser cutting machines are equally accurate.
While laser cutting technology has significant advantages in terms of accuracy, it cannot be absolutely said that it is the most accurate method in every situation. The accuracy of laser cutting can be affected by a variety of factors such as the type of material, the thickness of the material, and the maintenance of the machine. In some specific processing scenarios, such as the processing of certain special shapes and materials, other cutting methods such as CNC machining may instead be able to achieve higher accuracy and better meet production requirements.
Some people mistakenly believe that thick materials can be laser cut with the same level of accuracy as thin materials, but this is actually not in line with the actual situation. As mentioned earlier, thick materials in the laser cutting process, the laser beam is prone to diffusion, heat dispersion and other issues, which will have an impact on the flatness of the cutting edge, the accuracy of the size and other precision indicators, making it difficult for thick materials to achieve a high level of cutting accuracy as thin materials.
The scope of application of laser cutting technology is far beyond metal cutting, it can also be effectively used in plastics, wood, glass and ceramics and other materials cutting processing. Only, different materials due to their own characteristics are different, in the laser cutting needs to be targeted to set up different parameters, in order to ensure that the best precision effect. Therefore, laser cutting cannot simply be considered to be limited to the field of metal cutting.
Before carrying out laser cutting operations, the first thing to do is to carefully select the material to ensure that the selected material is the current laser cutting machine can be effectively processed. This is because even seemingly similar materials, such as different types of wood, can have very different material properties. Alder is a softer, less resinous wood, while cherry is relatively hard and highly resinous, which results in a very different machine setup for laser cutting of cherry than alder. Therefore, after selecting the material, be sure to refer to the laser machine’s operation manual to accurately calibrate the machine’s settings according to the material characteristics.
Adjustment of cutting speed and laser power intensity is critical to laser cutting accuracy. If the cutting speed is too fast, the laser acts on the material for too short a period of time and cannot provide enough energy for each design element, and the final presentation may be an incomplete pattern or insufficient cutting depth. On the contrary, if the cutting speed is too slow, the laser stays on the material for a long time, the excessive heat generated will damage the workpiece, which in turn will seriously affect the cutting accuracy. Therefore, before formal cutting, it is recommended to test with a small piece of material.
The spot size of a laser beam is directly related to the length of the laser’s focal lens. As the laser beam passes through the focal lens, it is focused and forms a spot, and a shorter focal lens allows the laser beam to become more focused, resulting in a smaller spot size. The smaller spot size is like using a finer paintbrush tip, which makes it easier to cut patterns with intricate designs and fine details, and has a significant advantage over larger spot sizes in terms of cutting accuracy. Therefore, when conditions permit, the spot size of the laser beam can be reduced by selecting the appropriate focal length lens to improve cutting accuracy.
The laser cutting machine generates a laser beam through the laser tube, which is then reflected sequentially by multiple mirrors inside the machine and finally projected from the laser head to the workpiece for cutting. In the seemingly complex optical path, the positional deviation of any mirror may affect the propagation path of the laser beam, which in turn affects the cutting accuracy. Therefore, calibrating the laser beam reflector is a very important task.
As the basic support part of the laser cutting operation, the stability of the worktable should not be underestimated for its impact on the cutting accuracy. Imagine, if in the laser cutting machine work, the worktable shaking, vibration or its own structural instability on the verge of collapse, then no matter how high the precision of the laser cutting machine itself, how reasonable the parameter settings, the final cut out of the product accuracy will be seriously damaged. Therefore, it is necessary to ensure that the use of the table has good stability, to avoid problems caused by the table cutting precision decline.
The precision of laser cutting is a complex issue affected by many factors, from the type and power of the laser itself, to the various characteristics of the cutting material, to the quality of the machine, environmental factors and the skills of the operator, etc., are closely related to it. At the same time, we also need to correctly understand the common misconceptions about the accuracy of laser cutting, to master the practical skills to improve the accuracy.
In the actual application of laser cutting, fully understand and control these accuracy-related points, for the realization of high-quality cutting processing, to meet the production needs of different industries is essential. Hope that through the introduction of this article, can help you better understand and use of laser cutting technology, in production practice to continuously improve the accuracy and quality of laser cutting.
