This article mainly analyzes the application of new laser marking technology, introduces the technique characteristics of nameplate laser marking and wire laser marking, and also describes the safety protection issues of laser marking technology.
Overview of marking technology
Traditional marking technology
In traditional manufacturing, marking technology has always been an important link.
This process can directly reflect product information on industrial products, such as the equipment nameplate reflects the basic parameters of the product, the wire label reflects the company name and model, and the beverage label reflects the production date.
These codes are convenient for users to have a basic understanding of the product.
There are several traditional marking technologies, namely:
- Inkjet marking
- Steel needle engraving and marking
- Sticker logo, etc.
But these methods have corresponding process defects.
- Consumables are needed for inkjet marking. After spraying, the ink does not dry and maybe discolored in other processes.
- The engraving speed of steel needles is slow and the processing efficiency is low.
The new technology that came into being is laser marking technology.
Figure 1 Laser marking system
Laser marking technology
Principle of laser marking technology
Laser marking technology uses a short-wavelength laser to change the molecular structure of the outer surface of the material, so that the set information content is displayed at the corresponding marking position without causing mechanical deformation and thermal deformation of the processed material.
Laser marking technology is used to change the properties of the surface of the material. The marking information is not easy to scrape. It only needs to be plugged in without special consumables, and the processing efficiency is very high. The maximum linear marking speed can reach more than 10000mm / s.
This technology perfectly compensates for various process defects of traditional marking technology and has been favored by various light and heavy industrial enterprises in recent years.
Two applications of laser marking technology
Nameplate laser marking technology
Nameplate laser marking technology is widely used in nameplate processing in various industries.
Its laser generation methods are mostly carbon dioxide and fiber optic materials.
Laser beams are used to permanently mark various surfaces.
The effect of marking is to expose deep substances through the evaporation of surface substances, or to make traces by chemical and physical changes of surface substances through light energy, or to burn away some substances by light energy, showing the pattern, text, barcode and other graphics to be etched.
The nameplate laser marking technology uses laser instead of traditional steel needle engraving, and the surface material of stainless steel nameplate is changed by fiber laser to engrave the corresponding setting information.
The processing speed of laser marking on nameplates is more than 10 times that of traditional steel needle engraving, and traditional steel needle engraving is only applicable to materials with softer materials, such as aluminum nameplates.
For high hardness materials such as stainless steel, the engraving effect is poor, the handwriting clarity is low, and it is difficult to identify with the naked eye, and laser marking solves this process defect, and the operation can be completed with high definition on the stainless steel nameplate (Figure 2).
Figure 2 Marking of stainless steel nameplate
The characteristics of the nameplate laser marking machine are summarized as follows:
(1) The laser power output is stable and the marking clarity is high;
(2) High processing efficiency, marking speed is 10 times or higher than traditional engraving machine;
(3) No operating system limitation, convenient operation and programming, fully closed and stable optical path, no maintenance required;
(4) Only electricity is needed, no other consumables are needed, and the equipment has a long life. The laser marking machine on the market has a life of more than 100,000 hours given by the manufacturer;
(5) Low noise, can be used in the office, and the power consumption is lower than traditional models;
(6) Super high precision, the resolution of the laser marking machine on the market reaches about 2500dpi;
(7) Compared with traditional equipment, since laser marking is used, there is no need to have any mechanical contact with the nameplate, so there is no need to set pneumatic nameplates or mechanical fixtures to fix the nameplate;
(8) Suitable for most metal materials (Figure 3).
Figure 3 Aluminum nameplate marking
The nameplate laser marking technology also has a new application feature than traditional engraving technology – bar code / two-dimensional code marking.
Because the laser marking technology programming software can receive BMP, JPG, DXF, PLT, AI and other format files and automatically generate various serial numbers, production dates, one-dimensional codes, two-dimensional codes, etc., the image processing capabilities are advanced, so adding barcodes, QR codes and other images on the nameplate can facilitate the management of the outbound, inbound and outbound of production materials, shelves, turnaround vehicles, etc., so that the information on the nameplate is improved from text to comprehensive reflection of text and images.
Marking technology programming
Compared with traditional programming software for engraving and marking steel needles, laser marking software is more simplified and easier to operate.
In terms of information positioning, a laser frame display is added. The user can directly open the laser frame, directly observe the position of the programmed information on the nameplate, and directly operate the arrow keys on the keyboard to adjust the information position. Compared with the positioning of traditional software, it’s much more convenient and quick.
At the same time, the software also adds a lot of functions, such as the insertion of images, the conversion of bar codes, two-dimensional codes, and can also receive BMP, JPG, DXF, PLT, AI and other format files.
These software upgrades also give the device more space and possibilities.
Wire laser marking technology
Figure 4 Laser marking of wire
As shown in Figure 4, the wire laser marking technology mainly uses a UV laser to directly interrupt the molecular chain of the material on the surface of the material through a short-wavelength laser, thereby displaying information on the corresponding trajectory.
Moreover, it is suitable for fine marking on the curved surface of the wire, which will not damage the wire core and will not cause mechanical deformation and thermal deformation of the wire itself.
Wire laser marking technology uses laser instead of traditional inkjet marking, and it can be seen in various comparisons that laser marking is better than inkjet marking.
Laser marking vs inkjet marking
Due to resolution and color contrast, laser marking has higher definition than inkjet marking, and inkjet printing needs to select different inks for different wire colors to highlight the contrast, and it is more troublesome to replace and operate;
(2) Processing efficiency.
Laser marking speed is much faster than inkjet marking, because the maximum linear speed of laser marking can reach more than 10000mm/s, and the marking time on the wire is within 1s.
For mass production of wire processing, the speed advantage of laser marking is particularly obvious;
(3) Process adaptability.
Laser marking is suitable for fine marking on the surface of the wire surface or marking on special materials that cannot be adhered by inkjet coding ink, and laser marking equipment can be used with automatic cutting equipment to form a wire processing line.
And inkjet coding can not be connected to automatic cutting equipment, because the wire is cut immediately after inkjet, and need to go through the mechanical structure of the guide wheel, straightening wheel, etc., which will wipe off the ink.
In terms of process applicability, laser marking is also better;
(4) Process costs.
The price of laser marking equipment on the market is slightly higher than that of inkjet marking equipment, but inkjet marking requires the purchase of ink.
For such large-scale workpieces as wire processing, the annual cost of ink consumables is also an expensive price.
In all aspects, the applicability of laser marking on wire coding is much higher than inkjet marking.
In recent years, major electrical companies have also continuously bought laser marking machine to replace traditional process equipment.
Laser marking equipment safety protection issues
Although laser marking technology has many process advantages, most of this technology is applied to industrial lasers.
Industrial lasers belong to the fourth category of laser products, which have certain damage to the eyes and skin. Therefore, safety precautions must be taken during use to avoid exposure to radiation from direct light scattered by the optical output mirror.
At the same time, appropriate precautions should be taken to prevent the output beam or reflected beam from directly hitting the human body.
Both scattered and reflected light can cause damage to the skin and eyes.
Always wear appropriate protective eye shields during operation. You can also install shielding tools within the scope of laser processing to isolate the radiant light and prevent the radiation light from causing damage to the eyes and skin.
Laser marking machine belongs to high-power Class IV laser equipment.
Most of the equipment emits light with a wavelength of about 1060nm above 10W, 20W, 30W, and 50W.
This level of light can cause damage to eyes and skin.
This emitted light is invisible, and the beam may cause irreparable damage to the cornea of the eye.
Always wear goggles when working with smart lasers.
(1) Do not install the sight when the laser marking equipment is working;
(2) When operating the equipment, do not look directly at the output head and ensure that you always wear goggles;
(3) Except for the controls, adjustments, or performance mentioned in the equipment, other operations may cause radiation exposure hazards.
External environment and preventive measures
Environmental protection measures for laser marking equipment can effectively avoid safety problems during use.
The specific measures are as follows:
(1) Laser equipment always works on a properly grounded and nominal voltage power source;
(2) This device has an output optical head connected via an optical cable, so you need to handle the output head carefully;
(3) When using the sight (such as when the sight is mounted on a fixture or when using the end face of an optical instrument), it is necessary to ensure that the smart laser is turned off;
(4) Do not expose the device to high humidity environments;
(5) Ensure that the ambient temperature and humidity are within the specified ranges before opening the equipment;
(6) It is forbidden to look directly at the output head, and ensure that laser goggles are worn when operating the product;
(7) When marking on high-reflection materials, use defocus marking, otherwise the smart laser will be directly damaged;
(8) The interruption of the supply voltage is very dangerous for the equipment, and it is necessary to provide a continuous and uninterrupted power supply;
(9) Except for the controls, adjustments or performance mentioned in the equipment manual, other operations may cause radiation exposure risks;
(10) For collimating lens output, keeping the output lens clean is the most basic. After use, replace the protective cover of the sight, do not touch the output lens, and do not use any solvent to clean, you can use lens tissue paper to clean.
Laser marking technology optimizes many process defects of traditional marking processes.
The comprehensive expansion of hardware and software makes the application of marking technology more and more widely, but its security protection issues should also be further improved.
After continuous development and R&D of this technology, I believe it will definitely bring more surprises to the manufacturing industry.