As a core piece of equipment in the field of industrial marking and processing, CO₂ laser marking machines have achieved wide application across multiple industries due to their unique technical characteristics. Below is a systematic overview and optimized explanation of such machines from four key dimensions: core definition, working principle, core advantages, and typical applications.
I. What is a CO₂ Laser?
A CO₂ laser is a type of gas laser that uses carbon dioxide (CO₂) gas as its core laser medium. It is also one of the most widely used laser types in industrial marking and cutting. Its core structure consists of three key components: a "discharge tube for enclosing CO₂ gas", a "total reflection mirror for light reflection", and an "output coupler for controlling laser output". Through the processes of gas discharge excitation and light amplification, a stable laser beam is ultimately emitted.
II. Working Principle of CO₂ Laser Marking Machines
The working process of a CO₂ laser marking machine can be divided into three core steps: **gas excitation → light amplification → laser output**. The specific process is as follows: 1. Gas Excitation: Plasma Generation The CO₂ gas enclosed in the discharge tube undergoes a discharge reaction under the action of a high-voltage electric field generated by the energized electrodes. Gas molecules are excited to a high-energy state and then converted into high-energy plasma, while releasing initial light signals. 2. Light Amplification: Enhancement via Reciprocal Reflection** The initial light signals reflect back and forth within the resonant cavity composed of the "total reflection mirror" and "output coupler". During each reflection, the light signals interact with the high-energy plasma in the cavity, continuously absorbing energy and being enhanced, thus achieving the "amplification effect" of light. 3. Laser Output: Formation of Directional Beam** When the energy of the light signal reaches a threshold, part of the beam is emitted directionally through the "output coupler" with a specific transmittance, forming a CO₂ laser beam with a wavelength of **10600 nm** (far-infrared band). This beam can be focused through subsequent optical systems for material marking or cutting.
III. Core Advantages of CO₂ Laser Marking Machines
Compared with traditional fiber laser marking systems (with a wavelength of approximately 1060 nm), CO₂ laser marking machines possess four core advantages—"versatility, high durability, low loss, and high efficiency"—thanks to their technical characteristics: "Wide Range of Applicable Materials and Strong Compatibility" Due to the relatively long wavelength (10600 nm) of the emitted laser, its energy is more easily absorbed by organic materials. Therefore, it can be efficiently applied to organic materials such as plastics, paper, wood, resin, and rubber, while also accurately acting on transparent materials like glass and PET. This addresses the issue of "difficult marking" for certain materials and demonstrates strong compatibility across multiple industries. Durable Markings to Meet Compliance Requirements The high-energy CO₂ laser beam causes physical or chemical modification on the material surface through "thermal action". The marked patterns/information (such as serial numbers and barcodes) are "resistant to fading, wear, and corrosion", and can remain clear for a long time. This advantage enables it to meet the strict "traceability" and "compliance" requirements of industries such as medical care and automotive—for example, permanent marking on medical device packaging and the application of traceability codes on automotive parts. Non-Contact Process to Reduce Loss and Costs. During the marking process, the laser beam has no direct contact with the material. This not only avoids physical extrusion or scratches on the marked material (especially suitable for fragile glass and thin paper) but also eliminates the "consumable wear" issue of traditional contact marking equipment, significantly reducing material waste and equipment maintenance costs. High Marking Efficiency to Improve Production Capacity** The CO₂ laser beam has concentrated energy and stable output, enabling high-speed scanning and marking (some equipment can achieve a marking speed of several meters per second). Even in high-speed production lines (such as assembly line operations in the packaging industry), it can maintain accurate marking effects, directly improving the production efficiency and capacity of enterprises. IV. Typical Industrial Applications of CO₂ Laser Marking Machines Relying on the above advantages, CO₂ laser marking machines have been deeply integrated into five core industries: "medical care, automotive, electronics, consumer goods, and packaging". The specific application scenarios are as follows:
| Application Industry | Core Application Scenarios | Application Value |
| Automotive Industry | Barcode/serial number marking on engine parts and wire harnesses; identification printing on rubber seals | Meets the strict compliance requirements of the medical industry, ensures product traceability, and avoids confusion or misuse |
| Electronics Industry | Model marking on circuit boards (PCBs); parameter marking on electronic components (e.g., resistors, capacitors) | Features high marking precision (capable of micron-level marking), adapts to the miniaturization needs of electronic components, and ensures the readability of marks in harsh environments |
| Consumer Goods Industry | Brand logo marking on daily necessities (e.g., plastic water cups, wooden tableware); custom pattern printing for personalization | Enhances the brand recognition of products, meets consumers' personalized needs, and improves market competitiveness |
| Packaging Industry | Production date/batch number marking on cardboard boxes; recycling mark printing on plastic packaging (e.g., PET bottles) | Adapts to high-speed packaging production lines, enables "real-time dynamic marking", ensures the accurate transmission of product information, and meets the efficiency requirements of the packaging industry |
| Medical Industry | Permanent marking on medical devices (e.g., syringes, surgical instruments); traceability code marking on pharmaceutical packagin | Meets the strict compliance requirements of the medical industry, ensures product traceability, and avoids confusion or misuse |
In addition, due to the strong controllability of the "thermal action" of the CO₂ laser beam, it is not only used for marking but also can be extended to "cutting scenarios"—such as cutting micro-holes on circuit boards in the electronics industry, cutting product gates in the injection molding industry, and achieving "half-cutting (for easy peeling)" of stickers in the packaging industry. This further enhances the multi-functional utilization of the equipment.
