Although there are many existing laser sources for decorating plastics, sealed carbon dioxide lasers are currently the most widely used, followed by lamp-pumped solid-state nd:yag lasers and diode pumped nd:yag devices in recent years. .
Most laser devices use high-speed beam-controlled galvanometer marking technology. This control device scans the laser beam with two computer-controlled mirrors or galvanometers that can move in the y-direction. “When the programmed laser path is completed, the new part is in place and repeats this cycle. Because the laser mode is completely in software, tools or masks are not required.”
Software for plastic marking with rotating beam control is also available from several laser equipment suppliers. This equipment is essentially the same technology but it is suitable for continuous rotary production such as Conveyor Belt or substrate conversion. Barbero explained that "the advantage of this equipment is that it can be easily retrofitted to existing production lines, The productivity is maximized. The code is fed back to the computer and the computer makes the appropriate adjustments to track the moving target in real time." Schlather went on to say, "The current device uses simple and straightforward graphics generation software that is easy to program and Single data is printed on each and every rotating part."
In recent years, the proceduralization, standardization and troubleshooting of laser marking have become easier and the speed of marking has also been greatly improved. Barbero said: "Today's software is suitable for more than 400 printings per second, and only 40 per second were printed 10 years ago." Most laser machine software has the ability to print serial and multi-models. Bar code and text of any model (including company logo). With the n1ndow-based "Help" option, laser marking suppliers added service and standardization techniques as well as fault clearing software.
Another development is the use of a laser light source to simultaneously print two parts. In addition to a deformation head and a programmed beam splitter, with the same information, a laser machine can print two parts at the same time. Schlather pointed out that this type of equipment can be used to print large areas or large quantities of parts that do not move parts.
Cost is a key factor in the ever-popular CO2 laser equipment. A complete set of CO2 turnkey equipment sells for between $25,000 and $35,000, while a tube-pumped or diode-pumped nd:yag device costs between $60,000 and $75,000.
The CO2 laser etched the plastic surface and cleaned the material by evaporation, resulting in a contrasting mark but with little or no real color change. Plastics suitable for printing on carbon dioxide lasers are pvc, abs and most polyesters. Mica-filled commercial resins, such as instant CO2 lasers, produce a frosty grey marking. Although the CO2 output power can reach 200W, the most common range for printing plastics is 10-25W, sometimes 50W (due to its high output), but the output power is also 30-50W devices. The yag laser is generally used for high quality marking of parts such as electronic connectors, hood components, lock caps, and surgical equipment. The rofin-baasel schlather advises processors to consider the required production volume and the aesthetic requirements for printing when considering a solid-state laser. For example, if you want a high-contrast, out-of-measured off-scale mark, the high-frequency laser performs best. However, this depends on whether the device's low output power suits your productivity requirements.
There is also a new type of diode, with a power between 3-loow, that can use a diode as a laser light source instead of the electron tube of the vacuum pump device. Diodes are said to be 50% more compact than electron tubes and energy efficiency is increased by 20% to 30%. Tube equipment needs water cooling, and the diode type needs water or air cooling. The electron tube generally needs to be replaced every 1000 hours, and the lifetime of the diode is 10,000 hours.
The disadvantage is that diodes are relatively new and expensive. For example, the diode pump laser of the foba50w is 10% more expensive than the 100W tube device but foba expects that the price of the diode device may drop in the next few months and they will eventually replace the tube pump device.
“Environmental issues are another driving force for the development of laser marking. Laser marking does not use inks or solvents, nor does it require high-intensity energy drying processes like ink marking technology.” Schlather of Rofin-Baasel sums up the choice of yag types : "If maintenance is required every 600-800 hours, then the pump investment is minimal, but maximum productivity can be achieved. If a 3-60 watt diode pump device can be used to complete the desired marking, the cost of the diode pump device will be within 5 years. Less than tube pump equipment."
