Laser Marking Systems / Laser Markers
CO2 Laser Marking
What is a CO2 Laser?
CO2 lasers use CO2 gas as their medium. CO2 gas is enclosed in a tube with electrodes used for electrical discharge. An electrical discharge generates plasma within the gas, and the generated light is amplified as it travels back and forth between the total reflective mirror and the output coupler. This light is eventually output as the laser.
CO2 laser markers feature a wavelength that's 10x longer than that of conventional fibre systems. They're great at marking plastics, paper, resins, wood, rubber, and transparent materials (like glass and PET).
CO2 Laser Feature: Commonly Used in Cutting Applications
CO2 laser markers rely on heat to mark parts, making them perfect for cutting applications. In fact, CO2 lasers are commonly used for cutting holds, gate cutting, and sticker half-cutting applications.
Compared to mechanical cutting tools, CO2 laser markers are fully automatable, flexible, and almost entirely maintenance free.
Wire sheathing cutting
CO2 Laser Feature: Synthetic Rubber Marking
Synthetic rubber has high heat and chemical resistance properties, meaning some marking methods are not strong enough to mark it. However, CO2 laser marking has very high heat absorption, allowing it to etch marks onto synthetic rubber.
CO2 laser marking synthetic rubber applications:
- Wiper blades
- Rubber gloves
- Car tyres
Rubber gasket - Head lamp
CO2 Laser Feature: Marking on Glass
Glass has high heat resistance and is commonly transparent. Standard Fibre wavelength systems are unable interact with glass due to these properties; however, incorporating a CO2 laser makes the marking process seamless. CO2 lasers engrave white marks into glass by gently generating tiny cracks, micro-fractures, using low power. The micro-fractures make up the mark or design.
CO2 laser marking glass applications:
CO2 Laser Feature: Marking on Cardboard and Wood
Using a CO2 laser for cardboard and wood marking ensures permanent marks that never smudge. The CO2 laser burns designs, logos, barcodes, or characters onto the wood or cardboard surface. CO2 laser marking is used for either white marking or dark marking.
CO2 laser marking cardboard and wood applications:
- Drink carton
- Decorative wood sign
- Shipping box
Wood label replacement
World's first 3-axis control 3-Axis CO2 Laser Marker ML-Z Series
KEYENCE's unique 3-axis control incorporated into the ML-Z CO2 laser marking machine ensures distortion-less marking over the entirety of its field of view. It allows the focal distance to be adjusted over a 42 mm range. This enables precise marking on 3D part shapes and reduces tooling costs. The ML-Z CO2 laser uses the 3-axis control to mark uniformly across step, inclined, cylinder, and circular cone targets and can even use CAD data of non-standard shapes to map its focal path and retain focus.
300 mm wide area
The wide-area models in the ML-Z Series CO2 laser have a marking area of 300 x 300 mm, which greatly simplifies installation costs and reduces processing time.
Variable Beam Spot and Defocusing
The ML-Z CO2 laser marking machine uses focal point and beam spot adjustment to mark various character types. The variation allows marking thin, thick, shallow, or deep characters in the same motion and allows for variability of power density to achieve perfect marks over a wide range of materials.
Conventional Laser Marker
With conventional models, marking is limited to a fixed area.
3-Axis Control ML-Z Series
With the ML-Z Series, high quality marking is possible over a wider area using 3-Axis control.
Improving Quality with Short-Wavelength and Thin Laser Types
9.3 μm vs. 10.6 μm wavelength
ML-Z Series laser markers feature two distinct wavelengths: 9.3 μm and 10.6 μm. The slightly shortened wavelength has a higher absorptivity in transparent materials like resin and glass. As a result, the shorter wavelength model allows for precision marking, shallower engraving, and less surface swelling.
Thin laser type
ML-Z Series laser markers also feature different spot sizes. Smaller spot diameters enable fine-print marking and greater power density, which in turn allows for more efficient processing like cutting and drilling.
9.3 μm Short Wavelength Model
10.6 μm laser
Deep engraving with extensive damage.
9.3 μm laser
Sharp, shallow engraving with minimal damage.
Relationship between wavelength and transmission ratio (PET)
The wavelength of the ML-Z Series’ laser is available at 10.6 μm as well as a shortened 9.3 μm to better suit the heat absorption characteristics of various resins. With a higher absorption rate in resin, this shorter wavelength allows for more precise marking with shallower engraving and less surface swelling.
Thin Beam Model
Compared with standard models, the laser spot diameter is smaller, enabling even finer marking. The smaller spot diameter allows for greater power density, which in turn allows for more efficient processing such as cutting and drilling.
Comparison of Laser Spot Diameter and Power Density
|Standard mode||Thin beam mode|
Thin beam mode
Thin beam mode
* These are representative values
Thin beam model
Thin laser beam models provide greater power density with a narrower spot diameter.
Introducing CO2 Laser Marking to Your Manufacturing Process
Do you process ceramics, glass, rubber, or cardboard? Are you looking for an efficient and precise marking process that standard fibre lasers struggle with? Test KEYENCE's CO2 laser marking machine for your cutting and marking needs.
Our expert team offers you a free demo, trial equipment, and after-sales support if you buy. Contact KEYENCE today to start processing with the ML-Z CO2 laser marker.