What is the laser cutter?
Laser cutting is one of the thermal cutting processes. It employs a focused high-energy laser beam to irradiate and heat the blank piece and makes the heated materials quickly melt or vaporize, and then shapes them into the desired geometry by movement of the beam.
An almost parallel laser beam is generated in the laser source; a mirror is used to direct the laser beam towards the cutting head; and a lens is used at the cutting head to focus the laser beam. The focused, high-energy laser beam shines on the surface of the workpiece, rapidly heating the workpiece and melting the material. Auxiliary gas is used to protect and cool the focusing lens as well as clear molten metal.
Categories of laser cutter
Laser cutting machines can be classified into three types based on the sort of lasers they utilize:
Fiber laser cutter: The fiber laser machine utilizes the SPI/IPG laser to turn electricity into light, which is then directed onto the surface of the blank piece through the cutting head. This high-energy laser beam rapidly vaporizes the material it comes into contact with. The primary application of a fiber laser cutter is the processing of metals such as stainless steel, carbon steel, and aluminum alloys.
CO2 laser cutter: It is a machine that utilizes CO2-based gas to produce a laser beam for the purpose of cutting or engraving materials. During this cutting procedure, supplementary gases like oxygen or argon are employed to enhance cutting velocity and purify the surface of the material. The primary application of a CO2 laser cutter is for non-metallic materials such as plastics and glass.
Crystal laser cutters: It utilize Nd:YAG (neodymium-doped yttrium aluminum garnet) and Nd:YVO (neodymium-doped yttrium vanadate) to produce laser beams for the purpose of cutting and engraving various materials. Typically, Nd:YAG is the more often employed option.
How does a laser cutter work?
The Laser cutter utilizes a high-energy laser beam to thermally alter the material, resulting in the cutting and shaping of the pieces. The workflow can be succinctly divided into four distinct parts:
1. Produce a laser: A laser beam is produced by a laser generator, which is a procedure similar to activating a flashlight.
2. Facilitates laser focusing: The laser beam traverses a sequence of optical components, such as lenses and mirrors, that concentrate it onto a minuscule area with exceptionally high energy density.
3. Fabricate the material: The concentrated laser beam impacts the surface of the material, causing it to undergo either melting or vaporization, resulting in the formation of a minute aperture. The laser cutter follows a predetermined trajectory to shape the intended form.
4. Remove excess material: The laser cutter commonly employs an “auxiliary gas,” such as oxygen or nitrogen, to eliminate any surplus material within the cutting region, ensuring cleanliness and enhancing the cutting speed.
Appropriate Materials
The suitability of a material for laser cutting techniques is contingent upon its inherent physical and chemical characteristics. Laser cutting can be used to process materials that have low reflectance, thermal conductivity, and chemical stability. The common materials used for laser cutting include metals, plastics, and wood.
Metals: Metals are the predominant materials utilized in laser cutting. Due to the high absorption rate of laser beams by metal materials, it is possible to get high-quality cutting results. Laser cutting of metal materials has the benefits of rapid speed, exceptional accuracy, and minimal heat-affected zone. Consequently, it finds extensive application in automotive manufacture, industrial production, aerospace, and related industries. The common metals used for laser cutting include aluminum, stainless steel, copper, carbon steel, and titanium.
Plastics: Not every type of plastic is compatible with laser cutting procedures. The material must possess the capability to efficiently absorb laser energy without undergoing excessive melting or emitting hazardous substances. The commonly used plastics for laser cutting are acrylic, PEEK, nylon, and PE.
Wood: Laser cutting is well-suited for wood prototyping and the fabrication of intricate furniture components and creative patterns.
Inappropriate materials
As previously stated, certain materials pose challenges for laser cutting due to their high reflectivity, propensity for combustion, and emission of poisonous substances. Some examples of improper materials include carbon fiber, ABS (Acrylonitrile Butadiene Styrene), PVC (Polyvinyl Chloride), PTFE (Polytetrafluoroethylene), HDPE (High-Density Polyethylene), Fiberglass, PC (Polycarbonate), PP (Polypropylene).
Benefits
The benefits of laser cutting technology are evident. Below, we will explain some of these advantages.
Exceptional precision and accuracy: The precision of laser cutting is contingent upon both the laser itself and the accuracy of the motion mechanism. The standard tolerances for laser cutting often fall within the range of 0.003mm to 0.006mm, while other cutting instruments may have tolerance levels ranging from 1mm to 3mm or even more. Contemporary, top-of-the-line laser cutting machines employ linear motors and optical scales to attain positioning accuracy of ±0.001mm in certain instances.
Non-contact processing: Laser cutting is a non-contact technique, indicating that there is no direct physical interaction between the cutting tool and the substance being cut. This minimizes the abrasion on the cutting apparatus and mitigates the likelihood of contamination. The outcome is more pristine, with negligible alteration of the substance. Laser cutting is capable of processing delicate or malleable materials due to its non-contact nature.
Rapid cutting velocity: With a laser power of 2KW, the cutting speed for carbon steel that is 8mm thick is 1.6m/min. For stainless steel that is 2mm thick, the cutting speed is 3.5m/min, resulting in a tiny heat-affected zone and low deformation.
A diverse assortment of materials: Laser cutting offers a wider range of materials that can be cut compared to oxyacetylene cutting and plasma cutting. It is capable of cutting metals, non-metals, composite materials, leather, wood, fiber, and more. Nevertheless, the laser cutting compatibility of various materials varies based on their thermophysical properties and laser absorption rates.
Drawback
Laser cutting is constrained by the laser’s power and the equipment’s size, thereby limiting its ability to cut plates and tubes of only small to medium thickness.
As the thickness of the material grows, there is a substantial drop in cutting speed.
Laser cutting equipment is costly and necessitates a significant initial investment.
