Currently, the two most commonly used laser types for engraving are fiber lasers and CO2 lasers. When it comes to engraving acrylic, the choice between them depends on specific needs. Below is a detailed comparison:

Working Principles and Wavelengths

• CO2 Lasers: CO2 lasers generate laser beams using a gas mixture of CO2, nitrogen, helium, etc., excited by electricity. They operate at a wavelength of 10.6 microns, which falls within the mid-infrared band. This wavelength is highly effective for engraving and cutting acrylic. The laser beam is absorbed by the acrylic material, causing localized heating and vaporization, thereby achieving engraving.
• Fiber Lasers: Fiber lasers produce laser light through fiber-optic cables doped with rare-earth elements such as ytterbium. They operate at a wavelength of 1.06 microns, which is better suited for metals, plastics, and some coated materials. However, when engraving acrylic, the absorption rate of this wavelength by acrylic is relatively low. The laser beam tends to penetrate the acrylic material, making it difficult to achieve the desired engraving depth and quality.

Material Compatibility

• CO2 Lasers: CO2 lasers are versatile for non-metallic materials, including wood, acrylic, glass, leather, fabric, paper, and rubber. They are particularly effective for engraving and cutting acrylic. They can produce smooth edges on acrylic and achieve high-quality engraving results. Whether it is cast acrylic or extruded acrylic, CO2 lasers can handle them well.
• Fiber Lasers: Primarily used for engraving metals such as steel, aluminum, brass, and titanium, they struggle with non-metallic materials like wood, acrylic, and glass. When engraving acrylic, fiber lasers may cause burning or charring rather than precise engraving.

Engraving Quality

• CO2 Lasers: CO2 lasers excel in engraving acrylic, offering fine details and smooth edges. They can produce clear and sharp markings on acrylic surfaces without causing significant heat stress or burn marks. The engraved areas typically exhibit a frosted or translucent appearance, enhancing the visual appeal of the acrylic. Additionally, CO2 lasers can achieve varying engraving depths by adjusting parameters such as power and speed, making them suitable for creating rich textures and patterns on acrylic.
• Fiber Lasers: Due to their limited compatibility with non-metallic materials like acrylic, fiber lasers may not achieve the same level of engraving quality as CO2 lasers. The engraved edges may appear rough or uneven, and the surface may develop heat-affected zones, which could affect the overall aesthetic and usability of the acrylic.

Engraving Speed

• CO2 Lasers: Moderate engraving speed, capable of efficiently engraving acrylic within a reasonable timeframe. For example, a 60W CO2 laser can engrave a 1mm-thick acrylic sheet at a speed of 10-20 mm/s.
• Fiber Lasers: While fiber lasers are fast for metal marking, their engraving speed on non-metallic materials like acrylic is relatively slow. Compared to CO2 lasers, they may require more time to complete the same engraving task on acrylic.

Maintenance

• CO2 Lasers: Require regular maintenance, such as cleaning mirrors and lenses, replacing gas, and calibrating the laser tube. The mirrors and lenses may accumulate dust or become misaligned during use, affecting laser performance. The gas inside the laser tube may also degrade over time, necessitating periodic replacement. The lifespan of the laser tube is typically around 10,000–30,000 hours.
• Fiber Lasers: Nearly maintenance-free, with no mirrors or gas to replace. They have a solid-state design, fewer moving parts, and minimal wear and tear. The lifespan of fiber laser diodes can reach up to 100,000 hours.

Operational Costs

• CO2 Lasers: Higher operational costs due to factors such as gas consumption, electricity usage, and consumables. The gas used to produce the laser beam needs to be replenished periodically, and the power consumption of CO2 lasers is relatively high. Additionally, frequent maintenance increases operational expenses.
• Fiber Lasers: Lower operational costs, with high electrical efficiency (30-50%) and minimal consumables. They consume less electricity and have no gas consumption. Over the long term, operational costs are significantly reduced.

Initial Investment Costs

• CO2 Lasers: Lower initial cost, with entry-level models starting at approximately $500. They are relatively affordable for hobbyists and small businesses.
• Fiber Lasers: Higher upfront cost, with entry-level models typically starting at around $3,000.

Application Scenarios

• CO2 Lasers: Widely used in industries such as signage, woodworking, acrylic crafts, leather engraving, and textile cutting. For example, they are suitable for engraving acrylic signs, decorative panels, awards, and trophies.
• Fiber Lasers: Primarily used for engraving metals in industrial part marking, QR codes, barcodes, jewelry, medical devices, and electronics. They are less commonly used for acrylic engraving.

In summary, if the primary focus is on acrylic engraving, CO2 lasers are generally the preferred choice. They offer better compatibility with acrylic, produce higher-quality engraving results, and provide smooth edges. Fiber lasers, on the other hand, are more suitable for metal engraving. However, advancements in hybrid laser technologies are emerging. Some advanced machines combine CO2 and fiber laser modules, offering flexibility for projects involving mixed materials. But these are typically high-end systems suited for commercial use.