Brief introduction of laser marking technology
Laser marking is a marking method which USES high-energy density laser to illuminate the workpiece to make the surface material vaporize or produce discolored chemical reactions, thus leaving a permanent mark.Laser marking can produce a variety of text, symbols and patterns, with characters ranging in size from millimeters to microns.
The basic principle of laser marking is that high energy continuous laser beam is produced by laser generator.The focusing laser ACTS on the base material and makes the surface material melt and even evaporate instantaneously.By controlling the path of the laser on the material surface, the desired image and text markers are formed.Laser marking is characterized by non-contact processing. It can be marked on any surface of any shape without deformation or internal stress. It is suitable for marking metal, plastic, glass, ceramic, wood, leather and other materials.Laser can mark almost all parts, and marks wear resistance, production process is easy to realize automation, marking parts deformation is small.Laser marking machine adopts scanning marking method.The laser beam is incident on two mirrors, and the scanning motor is controlled by a computer, which drives the mirror to rotate along the X axis and the Y axis respectively.After focusing the laser beam, it falls on the marked workpiece, forming the marking mark
Advantages of laser marking:
The focused ultrafine laser beam ACTS as a tool for removing material from an object's surface bit by bit.Its advantage is that the marking process is non-contact processing, no mechanical extrusion or mechanical stress, so it will not cause damage to the processed object.Due to the small size after laser focusing, small heat-affected area and fine processing, it can complete some processes that cannot be completed by traditional methods.
Laser machining is based on a focus and does not require additional equipment or materials.As long as the laser can work normally, it can be processed continuously for a long time.Laser processing speed and low cost.Laser machining is automatically controlled by a computer.
The projection marking system consists of a laser, an optical mask and an imaging lens.The system works by uniformly projecting the expanded laser beam of the telescope onto the prefabricated optical mask, and the light passes through the cavity.The figure on the mask is imaged onto the workpiece through a lens.Usually each pulse forms a mark.The surface of the material radiated by the laser is rapidly heated and vaporized or subjected to a chemical reaction, which causes the color to change, forming a clear, distinguishable mark.Generally, CO2 laser and YAG laser are used for projection labeling.The main advantage of projection marking is that a laser pulse can produce a complete mark, including several symbols, so the marking speed is fast.
An array of tag
The array standard USES several small lasers to emit pulses at the same time.After passing through a mirror and a focusing lens, several laser pulses ablate (melt) at the surface of the marked material, creating small pits of uniform size and depth.Each character and pattern is made up of these small circles and black pits.
Scanning scoring system by computer, laser and x-y scanning mechanism of three parts, its working principle is the need to hit the bottom input information into the computer, the computer according to the preliminary design of program control laser and x-y scanning mechanism, make a special optical system of the transformation of high energy laser spot scanning movement, form the processing surface markers., the following are two scanning methods:
1) Mechanical scanning
The mechanical scanning marking system does not move the beam by changing the rotation Angle of the mirror, but by translating the x-y coordinate of the mirror mechanically, so as to change the position of the laser beam reaching the workpiece.The X-Y scanning mechanism of the marking system is usually modified by a plotter.
2) Scanning mode of galvanometer
Galvanometer scanning marking system is mainly composed of laser, XY deflection mirror, focusing lens, computer and so on.Its working principle is the incident laser beam two reflector (galvanometer), using computer control specular reflection Angle, two reflectors along the X, Y axis scanning respectively, so as to achieve a laser beam deflection, with certain power density of laser focus on marking material movement, according to the requirements of the permanent marks on the surface material, which focus the light can be circular or rectangular.