The current background of glass drilling
Glass has good transparency and chemical stability, and is very widely used in life. In the fields of special glass such as medical, chemical, and photovoltaic, with the development of science and technology, the demand is also increasing year by year. Here are some common classifications of glass and their processing characteristics:
1. Soda-lime glass, ultra-clear glass and K9 glass
● Soda-lime glass (ordinary glass)
● Ultra-clear glass (low iron glass)
● K9 glass
This type of glass has good toughness and hardness, and is suitable for drilling holes with a thickness of 0-20mm.
2. High borosilicate glass and quartz glass
● High borosilicate glass: excellent light transmittance and very low coefficient of thermal expansion.
● Quartz glass: often used in optical lenses, it has extremely high hardness.
In the processing of this type of glass, thermal expansion and contraction or laser lobes are usually used. With the continuous development of laser technology, laser glass drilling has gradually become a new processing option. For the processing of high-hardness glass, lasers with high peak power are required.
3. Tempered glass
Tempered glass is a type of prestressed glass that forms compressive stress on the surface by chemical or physical methods, thereby improving the strength and load-bearing capacity of the glass. Its resistance to wind pressure, cold and heat, and impact has been enhanced. However, tempered glass can no longer be cut after processing. When the tempered glass is broken, the fragments are honeycomb-like obtuse particles, which reduces the harm to the human body.
Different glass types have their own advantages and processing requirements in different application scenarios, and choosing the right processing method and tool is the key to ensure the quality of processing.
Advantages of laser glass drilling
Glass drilling is a key link in glass production and further processing, and its importance is self-evident. At present, the traditional glass cutting process mainly includes two ways: knife CNC cutting and waterjet CNC cutting. For small businesses or those with limited budgets, these two traditional cutting methods are difficult to promote due to their high cost.
Laser glass drilling is a non-contact process that uses a focused laser beam with high energy density to melt or even vaporize the glass. The laser uses the light transmission of the glass to focus on the bottom layer of the glass, and uses the 2.5D galvanometer to scan at high speed, removing the glass layer by layer from the bottom to the top, and can process different thicknesses and types of glass. In addition to the initial cost investment, laser cutting glass does not require subsequent consumables costs, and has gradually become an important choice in the glass processing industry.
This time, the YDFLP-M8-200-S-W-V2 laser, with 2.5D galvanometer, and three-dimensional cutting software and hardware system were used for experiments, which can realize the perforation and cutting of conventional round holes or special-shaped glass. Compared with traditional mechanical drilling, this system has high processing efficiency, low maintenance costs and low thermal impact.
01 Influence of laser parameters on glass drilling
(1) The influence of pulse width on glass drilling
The following is a drilling experiment for ultra-clear glass, the diameter of the circle is 10mm, the thickness is 3mm, and the cut-off frequency corresponding to the 6ns mode, 9ns mode and 12ns mode is used to test the influence of pulse width on glass cutting.
Fig.1 Effect of cleavage at different pulse widths and frequencies
Fig.2 Measurement of the average (left) and maximum (right) edge collapse
Through experiments, it can be concluded that the average and maximum value of 9ns are the best controlled, followed by 6ns, which also has good edge collapse, and the average and maximum values of 12ns are slightly larger, and the analysis is due to the heat accumulation at 12ns. The appropriate single pulse energy and peak power have an important impact on the control of the collapse edge, and the higher the single pulse energy and the higher the peak power under the same pulse duration, the better processing effect.
(2) The effect of repetition rate on glass drilling
Through experiments, it can be concluded that when the repetition frequency is the cut-off frequency, the processing efficiency is the highest, the processing time is reduced to reduce the heat accumulation, the collapse edge is the smallest compared with 90% and 110%, the output average power is low when the cut-off frequency is low, and the efficiency is low due to the decrease of single pulse energy and peak power above the cut-off frequency.
(3) The influence of power on glass drilling
In order to further explore the considerable influence of laser power on efficiency, the same parameter was tested by changing only the power percentage. The parameter is selected 9ns mode 280k frequency, the power percentage is set to 70%, 80%, 90%, and the efficiency of drilling a 10mm diameter hole in 3mm thick white glass is tested.
Through experiments, it can be concluded that with the increase of average power, the peak power of the laser increases, and the time required to drill holes of the same thickness and the same hole diameter decreases.
02 Laser special-shaped drilling experiment
The laser outputs the laser beam, and the galvanometer motor realizes the high-speed movement of the laser beam through high-speed movement, and then focuses to the working range through the F-Theta lens, which is convenient, controllable and adjustable, and provides a competitive solution for the automatic processing and integration of the equipment.
Fig.3 The working principle of the galvanometer
The figure below shows the special-shaped drilling effect using the YDFLP-200-M8-S-W-V2 laser, and the chipping edge is less than 400 microns, and the edge effect is excellent.
Fig.4. Effect of special-shaped drilling
03 Drilling experiments on glass of different thicknesses
In the glass drilling industry, increasing efficiency and reducing costs are a common pursuit. Solving the pain points and difficulties of the industry is the goal of Jieput's unremitting development. The higher single pulse energy and higher peak power significantly increase the processing efficiency. The following is the use of YDFLP-200-M8-S-W-V2 to test the processing efficiency of different thicknesses and drilling diameters, for reference only.
Machining time corresponding to drill thickness/diameter
04 JPT M8 series lasers
Since its launch in 2021, the JPT M8 series lasers have been upgraded and optimized for multiple power levels for different applications. Low- to medium-power lasers (e.g., 20 watt, 50 watt) are suitable for surface treatment and etching of heat-sensitive materials. Medium to high power lasers (100 watts to 300 watts) excel in high-efficiency, demanding applications such as deep cutting, deep engraving, and glass frosting.
图5 YDFLP－200－M8－S－W－V2 外观图
On the basis of maintaining the function of independent adjustment of pulse frequency of JPT M7 series, the M8 series has focused on optimizing the pulse peak power and beam quality. The series can maintain excellent beam quality under high-power operating conditions, with a peak power of up to 300KW. The high-efficiency M8 series lasers bring a new and efficient processing method to the field of industrial automation processing.
Fig.6 YDFLP-200-M8-S-W-V2 performance index and peak power curve
05 Application of complex material properties
According to the characteristics of the M8 series of high-peak lasers, some effects that cannot be achieved with ordinary infrared fiber lasers can be achieved, such as marking on plastics. There are many common types of plastics, usually 1064nm infrared fiber lasers are considered unsuitable for marking on plastic materials, and ultraviolet solid-state lasers or CO2 lasers are commonly used. However, the low-heat nature of high-peak lasers makes this marking possible.
Fig.7. High-contrast color effect of POM plastic and ABS plastic
Compared with the various problems existing in traditional contact processing, the non-contact processing method of high-peak and high-power lasers has significant advantages. Although the initial investment is larger, the subsequent processing is more stable and requires less continuous investment. In applications with complex material properties and physical properties, the JPT M8 series of high-peak lasers can be easily handled and completed with high quality thanks to their excellent beam quality and adjustable parameter selection.