I. What is a laser marking machine?
A laser marking machine employs high-energy density lasers to locally irradiate portions of a workpiece, causing the surface material to vaporize or undergo color-changing chemical reactions, thus leaving a permanent mark.
II. Types of laser marking machines
1. Based on the material absorption characteristics of lasers, lasers can be divided into two main categories. One type uses lamp-pumped YAG (solid state) lasers, while the other uses CO2 (carbon dioxide) lasers.
2. Based on different types of lasers, we can categorize into: CO2 laser marking machines, semiconductor laser marking machines, YAG laser marking machines and fiber laser marking machines.
3. Classification according to laser visibility can be: ultraviolet laser marking machines (invisible), green laser marking machines (visible laser) and infrared laser marking machines (invisible laser).
4. According to different laser wavelengths, they can be grouped as: deep ultraviolet laser marking machines (266nm), green laser marking machines (532nm), YAG laser marking machines with pump lamp (1064 nm), YAG semiconductors with side pumping. laser marking machines, end-pumped semiconductor YAG laser marking machines (1064 nm), fiber laser marking machines (1064 nm) and CO2 laser marking machines (10.64 um).
III. Working principle
1. Lamp Pump YAG Laser Marking Machine:
It uses a krypton lamp as the energy source (excitation source) and ND:YAG as the medium to produce the laser.
Emission of a specific wavelength can induce the work material to produce an energy level transition and release a laser. After amplifying the laser energy, a laser beam is formed for processing the material.
2. CO2 laser marking machine:
Using CO2 gas as the working substance, the machine fills the discharge tube with CO2 gas, which serves as the laser production medium.
When a high voltage is applied to the electrode, the discharge tube generates a luminous discharge, freeing the laser from the gas molecules. After amplifying the laser energy, a laser beam is formed for processing the material.
3. Semiconductor side pumping YAG laser marking machine:
This machine employs a semiconductor laser diode with a wavelength of 808nm to pump the Nd:YAG medium, leading to the formation of a large number of inverted particles.
Under the effect of Q-switch, a giant pulse laser output with a wavelength of 1064 nm is produced. This machine has high electro-optical conversion efficiency and is capable of marking metallic and non-metallic materials.
4. Fiber laser marking machine: This machine emits the laser directly through the fiber.
4. Scope of Marking and Technical Parameters
1. CO2 laser marking machine:
This machine can engrave a wide variety of non-metallic materials, such as paper, leather, wood, plastic, plexiglass, fabric, acrylic, bamboo, rubber, crystal, jade, ceramics, glass and artificial stone.
It employs a CO2 gas laser tube, an expanding focus optical system and a high-speed galvanometer scanner. It is stable in performance, long-lasting, maintenance-free and economical.
Technical parameters:
- Laser wavelength: 10.64μm
- Laser repetition frequency: 20-100kHz
- Standard engraving range: minimum 2.5mm x 2.5mm, maximum 500mm × 500mm
- Engraving depth: ≤2mm or ≤8mm
- Engraving line speed: ≤7000mm/s
- Minimum line width: ≤ 0.05 mm or ≤ 0.15 mm
- Repeatability Accuracy: ±0.001mm
- Machine power: Minimum 300W, Maximum 4KW
- Laser power: 10W, 30W, 50W, 100W
2. YAG Galvanometer Laser Marking Machine:
Suitable for a variety of materials including metals, metal oxides, glass and plastics. Its high-speed scanning mirror can complete image scanning in a very short time, resulting in exquisite markings.
The design is rational, the craftsmanship refined, and the appearance is premium. It can be equipped with CNC rotary head, automatic accessories and loading/unloading production line according to user needs.
3. Green laser marking machine, ultraviolet laser marking machine:
Mainly used for ultra-thin IC products and other high-end applications. These machines are more expensive and usually customized.
4. Fiber Laser Marking:
Mainly used in fields where high requirements for depth, smoothness and precision are required.
V. Advantages of laser marking
1. The marking remains intact over time because the surface material is peeled off. Information can be preserved permanently.
2. Lasers can mark products with unique serial numbers, facilitating product identification and traceability. The special effects of laser marking are difficult to imitate with traditional processes.
3. Laser processing is non-toxic and harmless, without the disadvantages of processes such as screen printing corrosion.
SAW. Comparison between one-dimensional and two-dimensional codes
1. One-dimensional barcode:
A one-dimensional barcode expresses information in only one direction (usually horizontal) and does not express any information in the vertical direction. Its height is generally to facilitate reader alignment.
Disadvantages:
- Small data capacity: About 30 characters.
- Can only contain letters and numbers.
- The size of the barcode is relatively large (low space utilization).
- The barcode cannot be read if it is damaged.
2. Two-dimensional barcode:
A barcode that stores information in a two-dimensional space, both horizontally and vertically. It uses a particular geometric shape arranged according to certain rules in a plane (two-dimensionally). The alternating black and white shapes record the data symbol information.
Commonly used codes include Data Matrix, Maxi Code, Aztec, QR Code, Vericode, PDF417, Ultracode, Code 49, Code 16K, etc.
Benefits:
- High-density coding, large information capacity.
- Wide coding range.
- Strong error correction ability.
- Reliable decoding.
- Encryption measures can be introduced.
- Low cost, easy to make and durable.
