How a CO₂ marker works
A CO₂ laser marking machine uses a sealed tube filled with a gas mixture based on carbon dioxide, which emits infrared light at 10.6 µm. Organic and non-metallic materials absorb this long wavelength very well. In a galvo CO₂ marker, two scanning mirrors steer the beam through an f-theta lens over a fixed field. This is the same layout as a fiber marker, and it makes the machine fast for text and codes on parts that sit still or move past on a conveyor.
Marking sources are commonly in the 30 to 60 W range. Industrial markers usually use RF-excited metal tubes, which are compact and give a stable beam, while glass tubes are more common on flatbed engraving and cutting machines. Lower-power tubes are often air-cooled, and higher-power ones may need water cooling.
What CO₂ marks and what it does not
The CO₂ wavelength suits wood, MDF, bamboo, leather, paper, cardboard, cast acrylic, rubber, fabric and many painted or coated surfaces. On wood and leather it darkens the surface to give a contrasting mark, and on cast acrylic it leaves a frosted white engraving. On glass it produces a frosted mark by creating fine micro-cracks at the surface.
Typical jobs include wood products, leather wallets, acrylic trophies, kraft gift boxes and rubber stamps. Garment makers use CO₂ for denim fading and for garment labels and hang tags.
CO₂ does not mark bare metal. The 10.6 µm beam reflects off steel and aluminium, so a CO₂ machine can remove paint or powder coat from metal but cannot mark the metal itself. For bare metal, use a fiber laser marking machine. CO₂ marks on thin or curved glass can chip, and there a UV laser marking machine gives finer, cleaner results. PVC and vinyl must never be laser marked or cut, because they release hydrogen chloride gas.
Galvo markers and flatbed CO₂ machines
Galvo CO₂ markers keep the part still and move the beam with mirrors. They are fast and suit repeated marks on batches of parts or packs, over a field that depends on the lens and is often 100 x 100 mm or larger.
Flatbed CO₂ machines move the laser head on a gantry over a large bed. They are slower for small marks but can engrave and cut full sheets of acrylic and MDF, which makes them the usual tool for signage and plaques. The laser engraving machine page compares the two formats in more detail, including when a flatbed is worth the floor space.
CO₂ laser coders on packaging lines
On production lines, CO₂ is widely used as a coder rather than a stand-alone marker. A coder head sits beside the conveyor and marks batch numbers and expiry dates on labels, cartons, PET bottles and some films as products pass, with no ink or solvent to replace. NMB deals with Markem-Imaje coding and marking systems, and the Markem-Imaje laser coders page covers these. Where a substrate does not take a laser mark well, the Markem-Imaje CIJ printers page describes the inkjet alternative.
Line marking depends on conveyor speed and on the substrate. A label with a printed panel designed for laser coding marks quickly, while bare board needs more energy for a readable mark. The online laser marking machine page explains the sensor and encoder setup used on conveyors.
What to check before you buy
- Material list. List every material you will mark. A CO₂ laser marking machine covers most non-metals, but if even one product is bare metal, that job needs a fiber source.
- Galvo or flatbed. Choose galvo for fast, repeated marks on parts or packs, and flatbed for large sheets, cutting and full-area engraving.
- Source power. Around 30 W is commonly enough for marking wood and leather. Higher power helps line speed and deeper engraving in wood or acrylic.
- Field size. Match the lens to the largest single mark. A bigger field gives a larger spot and softer detail.
- Fume extraction. Wood and leather produce smoke, and acrylic gives off strong odours. A filtered extractor is essential, especially in shops close to homes or offices.
- Fire watch. Paper and wood can catch fire if the beam dwells too long. Do not leave a running machine unattended, and keep an extinguisher nearby.
- Laser safety. Use an enclosure with an interlock, or a controlled area with eyewear rated for 10.6 µm in an open setup.
NMB's CO₂ options
NMB Enterprises is an authorised distributor of IndoForeign Technologies laser systems, and the UV & CO₂ Specialised Markers in that range cover non-metal marking. NMB can look at your material and the mark you need, and say which source suits the job. For packaging lines, NMB also deals with Markem-Imaje CO₂ laser coders. The full IndoForeign range is on the products page.
CO₂ laser marking machine in Tamil Nadu
Interest in a CO₂ laser marking machine in Tamil Nadu comes from factories as well as small businesses. In the Vellore and Ambur leather belt, around Vellore, CO₂ suits logos and patterns on leather belts and bags. For knitwear units in Tiruppur, it suits labels and hang tags. The printing and packaging trade in Sivakasi works with paper and board, which CO₂ marks and cuts well.
In Chennai, gift and signage shops use CO₂ for wood and acrylic work such as wooden plaques and shields or name boards. Buyers outside Chennai can phone or WhatsApp NMB on 098417 60722 with photos of the product and details of the material, and NMB will suggest whether a CO₂ laser marking machine or a line coder fits. NMB is based at Poonamallee, Chennai 600056.