In industrial manufacturing, laser marking technology is increasingly replacing traditional marking methods due to its advantages of high precision, efficiency, and non-contact operation. However, with numerous laser marking machines available in the market, selecting the most suitable equipment has become a challenge for many businesses. This article provides an in-depth analysis of the three mainstream laser marking technologies—fiber laser, ultraviolet laser, and CO2 laser—comparing their principles, performance, and applications to offer professional guidance for equipment selection.
Laser marking machines can be categorized in various ways based on different classification standards:
This article focuses on the three mainstream laser marking technologies classified by laser source.
Fiber laser marking machines are currently the most widely used laser marking equipment in the market. They utilize fiber lasers as the light source and employ high-speed scanning galvanometer systems for marking. The working principle involves transmitting and amplifying light emitted by semiconductor lasers through optical fibers, which is then focused on the material surface for marking.
Working Principle: Fiber lasers use rare-earth-doped fibers (such as erbium or ytterbium) as the gain medium. When pumped by a semiconductor laser, stimulated emission occurs within the fiber, resulting in laser amplification and output. The laser beam is then shaped and focused onto the workpiece surface for marking.
Key Advantages:
Suitable Materials: Various metals and some non-metallic materials including stainless steel, carbon steel, aluminum, copper, gold, silver, and plastics.
Typical Applications: Fields requiring high precision in depth, smoothness, and fineness such as mobile phone components, watches, molds, integrated circuits, and mobile phone buttons. Fiber lasers can also mark bitmap patterns on metal and plastic surfaces at speeds 3-12 times faster than traditional lamp-pumped or semiconductor marking machines.
Ultraviolet (UV) laser marking machines, also called cold marking technology, use UV lasers as the light source and employ photochemical ablation for marking. Compared to fiber and CO2 lasers, UV lasers have shorter wavelengths and higher energy, enabling finer and clearer markings.
Working Principle: UV laser marking machines use high-energy ultraviolet beams to directly break molecular bonds in materials, causing vaporization or peeling to create surface marks. The short wavelength allows for smaller focused spots and higher energy density, resulting in finer markings with minimal heat-affected zones.
Key Advantages:
Suitable Materials: Heat-sensitive materials like plastics, glass, ceramics, and paper, as well as metals requiring high-precision marking.
Typical Applications: Electronic components, integrated circuits, mobile phone casings, LCD screens, food packaging, and pharmaceutical packaging—particularly for fine marking on non-metallic materials.
CO2 laser marking machines use carbon dioxide gas as the working medium, featuring CO2 metal lasers, beam expansion focusing optical systems, and high-speed galvanometer scanners. These machines offer stable performance, long lifespan, and maintenance-free operation. CO2 lasers operate at 10.64μm wavelength in the mid-infrared range, providing high power and electro-optical conversion efficiency.
Working Principle: CO2 lasers generate laser beams through electrical discharge excitation of CO2 gas. The output beam is expanded and focused onto the workpiece surface, causing rapid heating, vaporization, and ablation to create marks.
Key Advantages:
Suitable Materials: Primarily non-metallic materials including wood, leather, paper, plastic, glass, and acrylic.
Typical Applications: Handicrafts, leather goods, clothing, food packaging, pharmaceutical packaging, and electronic components—particularly for large-area and deep marking on non-metallic materials.
When choosing a laser marking machine, consider the following factors:
Fiber laser, ultraviolet laser, and CO2 laser marking technologies each offer distinct advantages for different materials and applications. Selecting the appropriate equipment requires careful consideration of specific needs and operational requirements. This comprehensive analysis aims to provide valuable insights for making informed decisions in laser marking technology adoption.
