LASER TREE
15-05-2023
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Here, we'll explore the features, benefits, and applications of Lasertree laser module, as well as provide tips, tutorials, and project ideas to inspire your creativity. Let's dive into the world of Lasertree laser modulecutting and engraving, and discover what you can create!
How To Identify A Good Laser Cutting Module
A laser cutting module is a high-precision integrated device which consisting of semiconductor laser diode, optical lens, a heat sink and a drive circuit. The optical solution and production process determine the core optical performance of the laser module - power and beam quality. Thermal design and drive circuit performance have a significant impact on product reliability. For engraving and cutting applications, the specific parameters of beam quality are the beam size at focus and Rayleigh length. In this way, optical power, beam size and Rayleigh length are the core optical parameters that determine the cutting performance of the laser module.
So, what kind of laser cutting module is a good laser cutting module?
Content
- Cutting Performance
- Engraving Performance
- Reliability
- Convenience
- Maintainability
- Compatibility
- Safety
Let’s start checking the factors one by one
Cutting Performance
- Cutting Depth
- Cutting Speed
- The Degree Of Carbonization In Cutting Section
- The Degree Of Carbonization On The Cutting Surface
- Variety Of Cutting Materials
- Size Of Cutting Port
- Durability Of Cutting Ability
Cutting Depth
1.Optical Power
Optical power is an important factor affecting the cutting depth, the greater the optical power, the deeper the cutting; the smaller the optical power, the shallower the cutting.
For example, our 30W+ optical power LaserTree K30 laser cutting module can cut a 20mm thick pine board at a time at 120mm/min. As comparison, with 20W optical power LT-4LDS-V2 to cut, the same parameters will take 2 passes to complete the cut.
The optical power can be measured directly with an optical power meter as showed in below.
2.Focus Position
The focus position of laser beam will affect the cutting ability of laser module, 1/4~1/2 thickness of the material below the surface of the material is the best position to get max cutting ability
3.Cutting Speed
The faster the speed, the shallower the cut; on the contrary, the slower the speed, the deeper the cut.
Cutting speed affects the cutting depth, we can use lasertree K30(30W+) laser module cutting data to do explanation as below
From the table we can see that when cutting 20mm pine boards, only 1pass is needed at the speed of 100mm/min, 2 passes is needed when the speed is increased to 130mm/min
Airflow Intensity Of Air Assistance
Why do we need air assistance during laser cutting?
During the cutting process, high temperature smoke is generated, which burns the material and increases the carbonization of the material surface and cross-section, which makes the cut material look black. At the same time, the increased carbonization makes the cutting process more susceptible to get fire.
1.Air assistance can blow away the high-temperature smoke generated during the cutting process in time, it is helpful to minimize the smoke stains and carbonization caused by high-temperature smoke, it can beautify cutting effect on material surface.
2.Air assistance can blow away the high-temperature smoke generated during the cutting process to reduce the carbonization effect caused by high temperature smoke on the cut section of the wood panel, it is helpful to improve the cutting depth.
3.In addition, the high-pressure gas in the air nozzle can effectively stop the smoke polluting lens, it is very helpful to improve the usage time of the lens.
4.Increasing the airflow strength of the air assist can increases the depth of cutting.
5.Beam Size At Focus
Beam size of the laser module is not square at focus actually, even it looks square at far field. Below is the beam size of laser tree LT-4LDS-V2 measured by beam analyzer, the beam size of focus at X and Y direction is different.
The beam size is shorter on the Y-axis and longer on the X-axis, and the laser beam energy stonger than the Y-axis per unit time. As a result, we can find that the X-axis can be cut through, and the Y-axis can not be cut through.
6.Rayleigh Length
In optics and laser science, Rayleigh length is defined as the distance of a beam along its direction of travel from its waist to a cross section whose area is twice the area of the waist, when the radius of the cross section is about twice the waist radius. Another relevant parameter is the confocal parameter (confocal parameter) b, which is exactly twice the Rayleigh distance.
From the above equation we can learn that the smaller the angle of clamping, the longer the Rayleigh length. The longer the Rayleigh length, the more suitable for cutting thicker materials.
Cutting Speed
The factors affecting the cutting speed are as follows:
1. Laser Power
The greater the optical power, the higher the energy, the faster the cutting speed.
Professional Laser Module for Laser Engraver
2. Focus Position
When focus position located at 1/4~1/2 thickness of material from material surface, the fastest cutting speed we can get.
3. Air Assist
Increasing the airflow intensity of air assist can speed up our cutting speed
4.Rayleigh Length
The energy distribution of laser beam in space is relevant with Rayleigh length, the thickness of material should be matched well with Rayleigh length, and then, the fastest cutting speed can be found.
5. Beam Size
The smaller the beam size, the higher the energy contacted per unit area, the faster the cutting speed.
The Degree Of Carbonization In Cutting Section
1.Cutting Speed
The laser has two effects on the material during the cutting process, namely carbonization and vaporization.
The ideal cutting effect is to maximize the effect of gasification and minimize the effect of carbonization.
The faster the cutting speed, the stronger the gasification effect and the weaker the carbonization effect.
The slower the cutting speed, the weaker the gasification effect and the stronger the carbonization effect.
2.Air Assist
Air assist can blow away the high temperature smoke generated during the cutting process in time to reduce the carbonization effect.
Degree Of Carbonization On The Cutting Surface
The degree of carbonization on the cutting surface is related to whether air assist is on or off. The air assist can blow away the high temperature smoke generated during the cutting process in time, which greatly reduces the carbonization on the surface of material, beautify the surface cutting effect
Variety Of Cutting Materials
1.Wavelength
Different materials have different absorption rates for different wavelengths of laser energy. 450nm blue light has a high absorption rate for wood, leather, metal and other materials; the absorption rate for glass, transparent acrylic and other materials is very low.
2. Material Thermal Conductivity
The stronger the thermal conductivity of the material, the greater the thermal energy loss, the worse the cutting effect; the weaker the thermal conductivity, the smaller the thermal energy loss, the stronger the cutting effect.
3. Laser Power
The greater the optical power, the higher the energy. Some materials need to absorb a certain energy intensity to achieve cutting, such as stainless steel.
Incision Size
1. Rayleigh Length
The longer the Rayleigh length the smaller the incision size.
2. Beam Size
The smaller the beam, the smaller the kerf when cutting.
3. Cutting Times
With the increasing number of cuts, carbonization will also be strengthened, which will lead to bigger incision size.
4. Focus Position
There is the smallest beam size at the focus, the suitable location of the focus position is helpful to reduce the size of the incision.
5. Air-Assistance
Air-assistance can timely blow away the high temperature smoke generated during the cutting process, greatly reducing the carbonization, which is helpful to reduces the size of the cut.
Continuous Cutting Ability
1. Heat Dissipation
Laser module is a photoelectric product, part of the input electrical power is converted into optical power, and the other part is converted into heat. The photoelectric conversion efficiency of blue semiconductor laser diodes is about 40%, which means that about 60% input power will be converted into heat during the working process.
This part of the heat will raise the working temperature of the laser module, and then reduce the photoelectric conversion efficiency of the laser diode, which makes the optical power of the laser module after stabilization lower than the initial working power, and this difference depends on the heat dissipation performance of the laser module. A poor heat dissipation means lower output optical power of the laser module after stabilization, the continuous cutting ability of the laser module will be decreased.
2. Air-Assistance
Air-assistance airflow can form positive pressure inside the air nozzle to stop the smoke from entering the air nozzle and contaminating the lens, lens contamination will affect the output optical power, and affects the continuous cutting ability.
3. The Reliability Of Laser Core
The long-term life of the semiconductor laser diode and the working temperature has a great relationship, high working temperature and over-drive of laser diode will accelerate the degradation of laser diode, and affects the continuous cutting ability.
4. Ambient Temperature
The ambient temperature will affect the laser module working temperature, the higher the ambient temperature, the higher the laser module working temperature, the lower the output optical power, the worse the continuous cutting ability.
Engraving Performance
1. Engraving Efficiency
The beam size at focus is the smallest, so we make the focus located on the surface of material to realize engraving. If you want to improve the engraving efficiency, you need to improve the power density at focus. There is only two ways to improve the power density at focus: improve the optical power and reduce the beam size at focus.
We can understand the engraving speed through the grayscale test board.
LT-K30(30W)
LT-80W-AA-PRO(10W)
By comparison, we can see that when the speed comes to 21000mm/min, K30 still has better color layering, while LT-80W-AA can only go to about 8000mm/min. So the greater the light power, the faster the engraving speed, the higher the engraving efficiency.
2. Resolution
The beam size at focus affects the resolution of engraving. The smaller the beam size, the higher the engraving accuracy; the larger the beam size, the lower the engraving accuracy.
3. Variety Of Engraving Materials
Different materials have different absorption rates for different wavelengths of laser energy. 450nm blue light on wood, leather, metal and other materials have a high absorption rate; on glass, transparent acrylic and other materials have a low absorption rate. The variety of engraving materials is limited accordingly.
Reliability
The laser cutting & engraving module contains three parts: driver board, heat sink and laser core. The reliability of each part can impact the overall reliability of the laser module. A good laser driver needs to meet the following requirements: low ripple, good surge protection and ESD protection. A good heat dissipation helps to improve the photoelectric conversion efficiency of laser module and slow down the degradation of laser diode. The reliability of the production process of the light source module itself, such as the material and coating types of lens, volatility and stability of glue can affect the reliability of the module.
Convenience
A good laser cutting module should be easy for customers to use. For example, positioning bar: it can help customers to adjust the focus position quickly; Red Cross alignment: it is helpful for user to place the materials you want to cut or engrave. Good features can make it easier for us to finish the work quickly and efficiently, saving time.
Maintainability
When users encounter predictable but unavoidable problems in the use of laser modules, it is especially important that they can quickly solve the problems themselves through simple operations. For example, the window protective lens at front of the laser emitter is easily contaminated by smoke, it will impact the cutting performance sharply, the window protective lens needs to be easily cleaned and replaced become very essential.
Compatibility
If you want to upgrade your laser module, you have to consider compatibility between your machine and new laser module, otherwise, you cannot use the new module well.
To realize the compatibility, you need to realize the electric and installation compatibility respectively. For electric compatibility, you need to enable the power supply and signal respectively. To enable power supply, you can use power adapter and adapter board, so that you can provide enough power to the laser module by power adapter & adapter board combination. To enable PWM signal input, you can use adapter board to realize the signal transmission be different interfaces. For installation compatibility, module seller always provide sliding plate which integrated mounting holes from different laser engraving machines in the market, and it can support lifting function also.
Safety
Laser module produce high intensity blue light during working, this light is very unfriendly to the human eye, the appropriate optical glass can effectively filter blue light, to protect the human eye.
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