Construction technology for laser micro-plate – plate making, laser – printing industry

Product Information

In the industrial production of gravure printing plates, the large surface area required a high degree of spatial resolution. The printed roll fast workflow requirements in a very short period of time, to micron-level precision effectively carving a number of square meters. Laser applications in this field has the following characteristics: processing high precision and focus with the advantages of digital modulation. As the precision, repeatability, flexibility and productivity gains, direct laser micro-structure technology is replacing traditional gravure plate-making technologies (such as chemical etching with a diamond pen or mechanical sculpture).

Rotary gravure printing plate by a uniform copper or galvanized steel roll formed. Image information is carved into a layer of copper or zinc in the small network of caves to ink transferred to the substrate (see Figure 1). A thin layer of chromium layer ensures presses remain under severe grinding a long service life. Through the use of scraper, to ensure that only delivery network point size to determine the amount of ink.

Gravure cylinder length of 0.3 to 4.4 meters, the circumference length of 0.3 ~ 2.2 m, surface area of up to 10 square meters. When the Screen resolution is 60 to 400 lines / cm, the cylinder number of points on the network is usually 108 ~ 1010. In order to make the most economical time image processing require a high laser pulse repetition rate and high average power.

Light for heat ablation for the way to large-scale micro-sculpture, the most effective way is: use a bunch of pulsed laser beam, the single laser pulse to create a complete network of point. A working focused 500 watts average power, repetition rate of 70 kHz tone QNd: YAG laser system (see Figure 3) make the zinc volume ablation rate 1cm3 / minute, an area of ablation rate of 0.1m2 / min . Net hole the shape of the waveform by the laser beam intensity of the decision.

Half-autotypical net points (in gray scale on the depth and diameter can be changed) can be Gaussian laser beam waveform generation, the traditional network points (gray value of each change on the depth of the same diameter) through the use of flat waveform generation (see Figure 2). Net hole depends on pulse energy, through the use of acousto-optic modulator controlled by the digital image data sets. The range of 25 meters to 150 meters in diameter, can be defined image Screen resolution; the range of 1 meter to 40 meters in depth, you can define the gray value of the printing point.

Melt thermal conductivity and thermal convection must be kept to a minimum. Therefore, Daetwyler has developed a fringe of organic Additive Special electro-galvanized material, its thermal conductivity lower compared with normal zinc structure. This special zinc ablation by vaporization, melting region and burrs can be reduced to a thin layer of sediment (network points around the 2 to 3 meters).

The drum surface by a continuous spiral track to turn carving cave network. When the rotational speed of 20 rev / sec, the processing of the first 15 to 150 microns / turn of the traverse feed rate, moving parallel to the cylinder axis (depending on Screen resolution). Net hole wall thickness between the net value of the maximum tone with only 4 to 6 microns. This requires precision aiming beam irradiation drum to about 1 micron.

Another method is to use pulse modulation of high power fiber laser (average power of 500 watts), the pulse repetition frequency range of 30-100 kHz modulation. When the frequency is 35 kHz, each pulse have more energy, allowing a single firing point can be drilled large network (such as the Screen of 70 lines / cm when the diameter of 140 microns). When the frequency of 100 kHz, the energy per pulse on fewer, thus carving out a small network of points (such as the Screen of 400 lines / cm when the diameter of 25 microns).

Laser beam operating a non-contact, and electrical and mechanical engraving with diamond pen than it is a key advantage. As long as the printing process with predictable and repeatable, and can guarantee the full width of the drum carved uniformity. It can be repeated because of the high rate of single-point single laser engraving process about 10 times faster than electromechanical.

Beam intensity modulation waveform

Printing market, there are many different substrate materials (such as paper or flexible foil), each with different surface characteristics of materials.

We are high quality suppliers, our products such as Bare Projector Lamps , China Projector Lens for oversee buyer. To know more, please visits Replacement projector lamp.

Find More Wood Plates ArticlesFollow Me on Pinterest
Be Sociable, Share!
Website Apps