1. Operation
1.1 Laser marking machine startup sequence
Emergency stop switch – Control switch – Computer – Laser switch
1.2 Laser marking machine shutdown sequence
Laser Switch – Control Switch – Emergency Stop Switch – Computer
1.3 Focal length adjustment and optical parameter calibration
Prepare a flat metal plate – Place the plate evenly on the work table – Start the marking software – Add and select pattern text – Select processing and continuous processing options, then start marking – Adjust the lever to up and down, find the strongest laser point on the metal plate – Stop marking and manually align the outer red dot with the inner red dot
2. Process control requirements for laser marking stations
2.1 Determine the font style according to the drawing requirements (including font shape, font size, stroke weight and text art)
2.2 Laser interaction with the part surface
The high energy density laser converges on the surface of the part, causing changes due to the different surface characteristics of the part. This includes surface etching of the part and oxidation of the part surface. Therefore, during marking, the characteristics of the material must be fully considered to achieve the best effect.
2.3 Laser beam quality
2.3.1 When observing with an upconversion plate, if the laser beam emitted under the field lens forms a regular circle and the internal distribution of the green halo is uniform, it indicates that the beam quality is good. If the light spot forms an ellipse and the inner green halo is defective, this suggests that the beam quality is poor, requiring adjustment by the correct method.
2.3.2 If the light spot is elliptical, you can precisely adjust the total reflection and frame of the output film to make it a regular circle.
2.3.3 If there are obvious defects within the light spot, the film surface is contaminated and needs cleaning.
2.3.4 By installing a small aperture diaphragm with suitable diameter at both ends of the laser rod sleeve, the laser output energy will decrease but the beam quality will be improved.
2.4 Influence of focal point position
The surface of the workpiece should be within the focal depth range of about 1mm to 2mm. At this time, the laser power density is the highest and the laser engraving effect is the best. This is usually identified by adjusting the lifting platform to observe the laser glow and sound on the metal plate to determine if the part surface is within the focal depth range. Sometimes, to achieve special marking effects, this can be achieved through positive blurring and negative blurring.
2.5 Impact of acousto-optical frequency and pulse width
Under a constant output current of the laser power supply, the peak power can be increased (although the average power decreases) by reducing the modulation frequency and pulse width of the acousto-optical switch. When the peak power of the laser is high, it easily forms an engraving effect on the surface of the workpiece. Likewise, by increasing frequency and pulse width, peak power can be reduced. When the average laser power is high, it tends to create a burning effect on the surface of the part.
2.6 Influence of Galvanometer Scanning Parameters on Marking
The marking parameters set in the marking software have a great impact on the marking results. Unreasonable parameter settings can lead to problems such as excessively heavy or lost strokes at the beginning or end of markup characters, excessively heavy curves or arc-shaped curves, and exceeding the limit during high-speed graph filling. For instructions on parameter adjustments, see the software manual.
3. Laser marking machine operation
3.1 Pre-Operation Preparations
3.1.1 To ensure safety, read this manual carefully.
3.1.2 The laser system employs a water-cooling method and the power supply uses an air-cooling method. If a malfunction occurs in the refrigeration system, do not operate the machine.
3.1.3 The internal circulating cooling water is deionized water (distilled water). For new equipment, the water should be changed once a month and, after half a year of use, it can be changed every two months.
3.1.4 Ensure the cleanliness of the work environment and that the ambient temperature meets requirements.
3.1.5 Remember not to look directly into the laser beam while operating the machine. Always wear laser safety glasses when working.
3.1.6 During machine operation, the circuit is in a high voltage and high current state. Non-professionals should not perform maintenance or repairs while the machine is turned on to avoid electric shock. The power supply and laser must be well grounded.
3.1.7 Except for adjusting the laser output power and overall optical path, troubleshooting should be done with the power supply turned off.
3.1.8 In case of machine failure, such as water leakage, electric arc, fuse problems or abnormal laser noise, immediately cut off the power supply.
3.1.9 If the overvoltage or overcurrent protection indicator lights up, immediately turn off the machine.
3.1.10 This machine is not suitable for use in flammable or explosive environments. Avoid using it in places with volatile solvents such as alcohol and gasoline.
3.1.11 Do not disassemble this machine at will. For significant failures, notify the manufacturer.
3.2 Machine Operation
3.2.1 Close the main pneumatic switch on the rear of the machine cabinet.
3.2.2 Insert the key, turn it on and connect the main circuit of the system by turning it 90 degrees clockwise.
3.2.3 Press the water pump switch to operate the cooling system and connect the water pump.
3.2.4 Close the laser power supply air switch, press the RUN button and the krypton lamp will automatically light up after (5-10) seconds, with the ammeter displaying about 7A.
3.2.5 Adjust the knob to change the krypton lamp output current, 17A is appropriate. (The current is set within (7-25)A internally in the power supply, the IGBT will shut down if it exceeds 33A and the main relay will cut off if it exceeds 40A).
3.2.6 Switch on the computer, scanner and acousto-optic indicator buttons sequentially.
3.2.7 Enter the WINDOWS operating system, open the laser marking software, set the appropriate parameters, and proceed with the laser marking work (refer to the software operation manual for software operation).
3.3 Normal Shutdown
3.3.1 After completing the task, sequentially turn off the indicator, scanner, computer and laser power switch.
3.3.2 Finally, wait one minute before turning off the water pump switch. Then pull the pneumatic switch to disconnect power to the entire machine.
4. Safety, environmental protection and occupational prevention in the operation of laser marking machines
The laser used in the laser marking machine is a Class 4 laser. The output laser is invisible infrared light, which can cause third-degree burns even when out of focus.
The output beam contains visible and invisible radiation, harmful to the human eye, and direct viewing of the laser beam is prohibited. To prevent accidental exposure of the human eye to the output beam or its reflected beam, all personnel near the equipment must wear specialized safety protective glasses.
Direct viewing of the indicator beam (laser used for indication) is also prohibited and must not be directed into the eyes of other people. Although the power of the indicator beam is low, direct vision is still harmful to the human eye.
5. Issues to be observed in the daily operation and maintenance of the machine
5.1 Daily Operation Precautions
a) Avoid direct visual contact with the laser.
b) Use the laser within a controllable area and display warning signs.
c) Unauthorized use is prohibited; only professionally trained personnel may operate the machine.
d) Strive to keep the height of the laser head unequal to eye level.
e) Pay attention to ventilation or exhaustion in the laser processing environment.
f) It is expressly prohibited for non-professionals to disassemble the machine due to the presence of lasers and high voltage components.
g) Field lenses should be cleaned with professional lens paper, using 99% pure alcohol, and only reinstalled after the alcohol has completely evaporated.
h) Protect the laser output field lens from smoke produced during operation, preventing the lens surface from being contaminated. Provide smoke extraction equipment. If the field lens becomes dirty, power may decrease; At this time, gently clean the surface with degreasing cotton or lens paper soaked in anhydrous alcohol.
i) Strictly prohibit placing any unrelated full or diffuse reflective objects inside the equipment to avoid laser reflections on humans or flammable materials.
j) The machine must be supervised during operation, especially when marking flammable materials, to avoid anomalies or fires. Unauthorized or untrained personnel must not operate the machine. Any damage caused by improper operation is not the responsibility of our company. Operators must always observe the operating conditions of the machine. As this type of laser is invisible, safety is paramount and flammable/explosive materials should not be placed within 2 meters of the device.
k) In case of machine malfunction or fire, immediately cut off the electrical supply.
l) Do not operate the machine when the relative humidity exceeds 80%, as this may affect the life of the machine or damage the electronic circuit.
5.2 Maintenance and Care
a) Cleaning the optical lens
b) Remove the field lens, blow off the dust from the surface and gently wipe it with degreasing cotton dipped in alcohol. Reinstall it as it was before after cleaning. Handle the lens carefully, gently cleaning it and positioning it to prevent it from falling out. Do not rub back and forth or use harsh materials for cleaning, as the special metallic coating on the surface of the lens may be damaged, leading to a significant reduction in laser energy. Check for leftover fibers or residue after cleaning and only turn on the machine after the alcohol has evaporated.
c) Checking the optical path
d) Perform a marking test before each startup to ensure that the optical path and other components are functioning properly.
6. Equipment maintenance and repair
6.1 Daily Maintenance of the Whole Machine
6.1.1 When the machine is not in operation, the machine cover must be sealed to prevent dust from entering the laser and optical system.
6.1.2 In case of malfunction (such as leaks, arcing, blown fuses, unusual noises, etc.), the power supply must be immediately cut off.
6.1.3 Internal circulating cooling water should be replaced regularly as needed, with a standard replacement period of once per quarter. If the equipment is used more frequently, the replacement period should be reduced.
6.1.4 For equipment that has not been used for a long time, the internal cooling water must be drained. In winter, the temperature of the cooling water must be above zero degrees to avoid the risk of breaking the glass tubes inside the chamber.
◆ Danger: Machine tool circuits have high voltage during operation. Non-professional personnel should not carry out maintenance while the machine is turned on to avoid electrical accidents.
6.2 Maintenance of the Optical System
6.2.1 Due to prolonged use of the device, dust in the air may adhere to the focusing lens, resonator diaphragm, mirror reflective film, and crystal end faces. This can reduce the laser power to a minimum or cause the optical lens to overheat and, in the worst case, burn out or burst.
6.2.2 Cleaning optical lenses: Mix anhydrous alcohol and ether in a 3:1 ratio. Dip a soft cotton swab or lens paper into the mixture and gently wipe the surface of the lens in a spiral motion from the center to the edges. Replace the cotton swab or lens paper after each cleaning.
6.2.3 Chamber cleaning: After prolonged use of one year, the inner wall of the purple filter glass tube in the chamber may develop a layer of scale due to problems with the quality of the cooling water, affecting the light output efficiency . It needs to be cleaned (this cleaning must be done under the manufacturer's guidance).
6.3 Regularly clean dust from the mesh cover and fan blades. The fan operation must be observed during the process.
6.4 In summer, when the indoor temperature and humidity are relatively high, condensation may form on the surfaces of the cooled laser crystal and acousto-optical crystals. Use must be stopped at this time, otherwise the laser film may be damaged.
6.5 Laser processing of parts may generate a small amount of spatter and smoke. Prolonged use may cause dirt to adhere to the surface of the field lens protective lens, thereby affecting the laser output energy. At this point, the protective lens needs to be cleaned.
7. Fault analysis and troubleshooting
7.1 If the “Protection” light comes on after the laser power is energized, check whether the water pump is on and whether the water cooling machine is working properly.
7.2 If the “Current” light turns on after the laser power supply is energized, you can turn off and restart the laser power supply. If the problem persists, this indicates an internal laser failure that requires specialist repair.
7.3 Misalignment of the optical path can weaken the laser energy. This can be corrected by adjusting the diaphragm rack and observing the laser beam output from the field lens using an upconversion plate, making the green laser spot on the upconversion plate round and large.
7.4 If light leakage occurs during the marking process, it may be due to incorrect positioning of the acousto-optic crystal or a reduction in power due to a malfunction in the acousto-optic power supply.
7.5 If the laser spot moves only in the horizontal or vertical direction during marking, remove the field lens. With the galvanometer system turned on, gently touch the edge of the galvanometer window. If a lens is not locked, it means a failure in the single-axis galvanometer system, which requires professional repair.
