Laser cutting is a method that uses a laser, a concentrated beam of light, to cut materials. It's mainly used in industrial work, but small businesses and hobbyists use it too. Laser cutting is versatile and precise, making it useful for big projects and small custom jobs alike.
How does laser cutting work?
In laser cutting, a machine generates a laser beam and aims it at a sheet or block of material. The laser beam is so focused and strong that it melts, burns, or vaporises the material's surface, allowing for marking or cutting through. The machine doesn't touch the material. Instead, the laser beam does all the work. That's why laser cutting is known as a non-contact process, and it comes with its own set of advantages.
How is the laser generated?
The laser in a laser cutting machine is created by using power to excite atoms. Regardless of the type of laser cutting machine, the process generally goes like this:
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Excitation: Energy, from electricity or light, is applied to a material known as the lasing medium. This could be a gas, a crystal, or a special kind of fibre. This energy excites the atoms in the lasing medium, causing them to rise to a higher energy state.
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Population inversion: After the energy is applied, more atoms are in a higher energy state than in a lower one. This unusual state is called population inversion.
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Stimulated emission: When an excited atom gets hit by a light particle (photon), the atom drops back down to a lower energy state, releasing another photon. This new photon is identical to the original one. This is how the laser makes more light of the same kind.
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Feedback mechanism: The laser has two mirrors that bounce the photons back and forth, stimulating the emission of more light. One of the mirrors lets a bit of light out, which forms the laser beam.
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Laser beam creation: The light that escapes through the mirror becomes a very focused beam of light. This laser beam is guided and focused using mirrors and a lens before it cuts the material.
How does the laser cut the material?
The laser doesn't physically cut the material. Instead, it heats the material to a very high temperature.
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Absorbing energy: The material absorbs the laser's energy, which turns into heat.
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Melting or vaporising: If the laser's energy is strong enough, it heats the material until it melts or vaporising, creating a small hole or gap in the material.
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Removing the material: An "assist gas" blows away the molten or vaporised material from the cutting area, leaving a clean cut.
What are the different types of laser cutting?
There are many types of laser cutting, each with its own benefits and drawbacks. Some of the most common include:
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Fibre laser cutters: These machines use a clear optical fibre coated with rare earth elements as the lasing medium. This is the most technologically advanced method of laser cutting due to its high cutting speed, increased precision, and its flexibility. We at FSM extensively use them in our sheet metal fabrication services.
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CO2 laser cutters: These machines use a tube of gases, including CO2, as the lasing medium. They are often used to cut non-metallic materials like wood, plastic, and textiles.
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Crystal laser cutters: Also known as Nd:YAG or Nd:YVO cutters, these machines use a crystal coated with an element called neodymium as the lasing medium. They are less common and can be costly to maintain.
What is fibre laser cutting?
In fibre laser cutting, the lasing medium is a clear optical fibre coated with rare earth elements. The energy and light in the laser creation process pass through the fibre and excite the atoms, similar to other cutting methods. Fibre laser cutting machines provide reliable, long-lasting service for projects involving metal.
Benefits of fibre laser cutting
There are many benefits to using a fibre laser cutting machine. These include:
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High precision and quality: Fibre lasers are usually more precise and accurate than other types of lasers. They produce a smaller "kerf" (width of the cut or groove), and the heat-affected zone is usually smaller, resulting in smoother edges and less need for post-processing.
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Speed: Fibre laser cutters are incredibly fast and efficient when working with thin materials, like sheet metal. They are also more energy-efficient, leading to less energy wastage overall.
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Versatility: Although we mainly focus on metal laser cutting, fibre laser cutters can work with a wide range of materials in various thicknesses.
Fibre Laser Cutting from FSM
With over twenty-five years of experience in laser cutting, FSM is an excellent choice if you're looking for a high-quality, efficient fibre laser cutting service for your next project. We use a cutting-edge Trumpf fibre optic laser cutting machine to deliver perfect results with impressively short lead times. We also save you money by cutting tooling costs and programming charges. For more information, contact us by phone (01440762651), email ([email protected]), or through our online enquiry form, and discover how we can help make your project a reality.