A laser engraver is a machine that uses a laser to engrave images, text, graphics on materials. Laser engraving is the process of evaporating material into smoke to engrave permanent deep marks. The laser beam acts as a chisel, cutting the mark by removing layers from the surface of the material. The laser irradiates a localized area with a large amount of energy to generate the high heat required for vaporization. Today, most laser engraving machines are CNC machines, which use a computer and CNC controller to control the movement of the laser or workpiece. Some laser engravers also do laser marking, which is a broader category of methods of leaving marks on objects, which also includes color due to chemical/molecular changes, charring, blistering, melting, ablation, etc. Variety.
A laser engraver consists of three main parts: the laser, the controller, and the surface. A laser is a drawing tool: it emits a beam of light that allows the controller to draw patterns on the surface. The controller determines the direction, intensity, speed of movement and spread of the laser beam aimed at the surface. Select the surface to match the type of material the laser can act on.
The point at which the laser beam touches the surface should be in the focal plane of the laser optics, which is usually synonymous with its focal point. This point is usually small, possibly less than a fraction of a millimeter. When the laser beam passes through the surface, only the area within that focal point is significantly affected. The energy delivered by the laser changes the surface of the material at the focal point. It may heat the surface and subsequently vaporize the material, or the material may crack and peel off the surface. Paint for cut metal parts is often the way the material is laser engraved. Types of materials that laser engraving machines can process:
1. One of the most commonly used materials for laser engraving machines is natural materials, especially wood. The laser power required to engrave wood is typically less than 10 watts. Hardwoods such as walnut, mahogany, and maple produce good results. Cork can be carved judiciously, but tends to evaporate at a less consistent depth. Laser marking cork requires a minimum power level. If you want to work on cork with strong laser power, active cooling, such as a fan with enough airflow to suppress ignition, is recommended. Cardboard and fiberboard can also be engraved.
2. Most types of plastic can be engraved. Laser irradiation can produce direct chemical modification, melting or evaporation of materials. Pure plastic is rarely seen due to the use of several additives such as colorants, UV blockers, mold release agents, etc. These additives can affect the results of laser marking. Standard cast acrylic, acrylic sheet and other cast resins usually laser well. A common engraved medallion is a cast acrylic shape designed to be laser engraved from the back. Styrene and many thermoforming plastics tend to melt around the edges of the engraving point. The result is usually "soft" and no "etched" contrast.
3. Metal is a heat-resistant material, and marking metal requires high-density laser irradiation. For uncoated metals, especially those with reflective surfaces, the laser may reflect off the engraved point, leaving enough energy to evaporate the metal, and painting the surface black can significantly prevent laser reflection. On the other hand, with coated metal, clean and impressive detail can be easily sculpted without black paint.
4. Stone and glass don't easily become gaseous, but when a laser hits glass or stone, something else interesting happens: it breaks. Pores on the surface expose natural grains and crystalline "slugs" that, when heated rapidly, can separate a microscopically sized "chip" from the surface as the heat block is expanding relative to its surroundings. So lasers are indeed used to engrave on glass, and if the power, speed, and focal length are just right, they can achieve excellent results.
5. Like ordinary etched mirrors, the initial focus of the laser engraver is to etch the image onto the glass surface of the mirror. Similar results to sandblasting or chemical etching can be achieved when power, focus and speed are optimized. In a new form of mirror engraving, a laser pulses through a reflective silver layer behind the mirror. Therefore, the glass side of the laser engraved mirror remains intact, maintaining the total reflection quality of the original mirror.