Six-color printing iron machine structure features, computer direct plate making and UV technology

Six-color printing iron machine structure features, computer direct plate making and UV technology

I. Introduction to the structural characteristics of the six-color printing iron machine
The following picture shows the NETER STAR2 six-color printing machine introduced by our company. It mainly includes feeding raceway, feeder, printing unit, glazing unit, UV ink curing system, online inspection device, receiving device and central control system. The technical parameters of the device are as follows:
Iron sheet thickness: 0.12-0.40 mm
Iron sheet width: 710-1200 mm
Iron piece length: 510-1000 mm
Maximum production speed: 10.000/hour
Its main features are:
1. High precision of overprinting, the precision can reach 5um.
2. High degree of automation, production speed up to 10,000 sheets / hour
3. Replacement time is short
4. The equipment runs smoothly
figure 1:
The following is a brief introduction to the structural characteristics of each part of the METER STAR2 six-color printing machine.
1. Feida: It is similar to the paper machine Feida, independent motor servo drive, high-precision synchronization guarantee, automatic control of the arrival time of the iron; KUNZIMATIC positioning device: pre-adjusting the sheet, front and side positioning using a pneumatic nozzle device, fast Replace the side gauges on both sides (running the corrugated iron) and replace the side gauges in less than one minute. It uses a unique iron sheet conveying method. Vacuum power supply, precision control below 15um, with patented technology.
figure 2:
2, VARISPEED positioning roller: intelligent tooth transfer device, extend the sheet transfer time, to ensure accurate transfer of the sheet at the highest speed. With the shifting drum unit, B+K uses two accelerations at the feed to ensure smooth transitions, and the oscillating jaws accelerate to 66% for the first time, and then accelerate to 100% by the shifting drum.
3, the unit: the replacement of the workpiece using fully automatic technology, the process only takes 45 minutes; the working speed can reach 10.000 sheets / hour; equipped with six printing units and a glazing unit; high-precision quality inspection and control facilities; The drum arrangement adopts the current 7 o'clock method in the world; the positioning accuracy of the feeding process is less than 15um, the registration error between each unit is less than 5um; the double-diameter impression cylinder and the transfer roller design; the plate monitoring and positioning device; The power transmission of the unit is free from the previous horizontal axis transmission mode, and the precision gear transmission can better ensure the overprinting accuracy. Newly designed guide assembly, integral cast iron frame, drum pre-tension and high-precision roller bearings to avoid gear tooth gaps, reduce vibration and ensure high print quality at maximum speed. (Figure 4)
Automatic drum cleaning device: The cleaning of three rollers (imprint roller, rubber roller, plate cylinder) adopts combined cleaning device, which can automatically clean six sets of rollers at the same time when changing orders, which takes about 10 minutes; two traditional metal When the printing press cylinder is changed, each group must be manually cleaned for about 10-15 minutes/time; in contrast, the preparation time is greatly saved.
5, automatic plate changing device: the traditional metal color printing equipment uses manual or semi-automatic plate changing device, and the equipment introduced this time uses a fully automatic plate changing device, which can automatically change the plate at the same time, this is a general It can increase the efficiency by about 5 times and reduce the labor intensity of employees.
6. Cavity scraper system: plate positioning and on-line glazing ensure partial glazing at high speed; on-line glazing unit adopts cavity scraper and anilox roller device to ensure quantitative supply of varnish, which can save The amount of varnish used.
7, iron film ejection detection configuration: design to reach 10.000 sheets / hour; iron tablets can be re-entered into the machine; can collect up to 200 iron pieces.
8, UV ink curing system: 4 UV lamps, each can only reach 160W / cm; energy to achieve stepless adjustment; can save energy.
9. Receiving device: The speed reaches 10.000 sheets/hour, and the independent iron plate reduction device.
10, the central control system: ERGOTRONTC central console, all control keys can be digitally controlled, the parameters of the work can be easily replaced, and through the job call function, can greatly shorten the printing preparation time (can store 10,000 sets of print jobs); The electronic standard components can be used all over the world. The positioning system consists of radial, axial, and diagonal registration. The ink zone control consists of each 30 mm wide ink zone, and each ink zone does not interfere with each other. Online color control includes density and chromatic aberration. Based on standardized and convenient operation, fully automatic iron plate size setting and pressure control. Controls and adjusts all basic printing parameters (such as ink volume adjustment, dampening fluid volume, registration accuracy, sheet size, cleaning program, etc.) with remote diagnostics; CTP3 connectivity and computer direct and j-version systems ( CIF); shorten the ink pre-adjustment time. It can be integrated with PRET CHECK3000 real-time quality monitoring system: single color registration, color classification, color difference and other issues can be monitored by Print Check 300 system, monitor the color and registration of the entire sheet, and display diagnostic fault information, so that the printer can appear Take precautionary measures before a large number of waste products.
Second, the introduction of UV printing iron ink printing operation points
Because UV printing ink has the characteristics of environmental protection, reducing pollution and increasing production speed, it has the incomparable advantages of traditional printing iron ink. Therefore, most developed countries in the world have adopted this technology. In China, UV printing iron ink printing technology has just started in China. Shanghai Baoyin Metal Color Coating Co., Ltd. has introduced an international advanced high-speed six-color UV printing machine from abroad, which has created a precedent for China's UV printing ink printing iron technology. Due to the late start of the technology in China, there has not been a complete set of process operations, and it can only be explored while producing. By summarizing the problems in production, and learning the experience of foreign UV-printed iron counterparts and consulting equipment, ink coating suppliers, the author draws the following points for the industry to discuss.
1. Ensure that the machine settings and pressures meet the normal requirements, and the glue, blanket and car wash water match the UV ink.
Since the binder of the UV printing ink is composed of an unsaturated acrylic monomer or a top polymer, the dissolution property of the conventional heat curing ink (mainly an alkyd) is different. Unsaturated acrylic monomers are highly aggressive, which can cause erosion and expansion of the rubber in the rubber and blanket, and damage the photosensitive layer on the surface of the PS plate, causing the image to fall off. Therefore, when printing with tin-printed UV-printed iron ink, it is necessary to use a special ink, blanket and car wash water for UV-printed iron ink. The PS plate must be baked at a high temperature to enhance the corrosion resistance of the graphic layer. The relevant adhesive and blanket material properties are described below.
Ink roller: 25 - 40 Shore hardness EPDM rubber or PVC Nitrile rubber roller
Dampening roller: 25 Shore hardness EPDM rubber or PVC Nitrile rubber roller
Blanket: >70 Shore Epoxy EPDM or PVC Nitrile Blanket (Quick Release) Note: Use EPDM rubber with extreme care not to use aromatic solvents ( Stone brain mooring, petroleum refining) cleaning
2. Ensure that the fountain solution meets the technical specifications.
Whether it is the traditional iron printing process or the UV printing iron process, it is the key to control the ink and water balance. The industry has a saying, "Whoever masters the dampening solution, who controls the printing" shows the importance of ink balance on printing. In the same way, we should master the principle of less water and less ink. However, due to the special composition and curing characteristics of UV printing ink, it has stricter requirements on ink balance control than traditional printing iron, and the range is narrower. See the following requirements for details:
A. The dampening solution has a pH of 4.8-5.2. If the acidity of the dampening solution is too strong or too weak, it will cause printing problems, such as ink emulsification, stenciling, dirty, faint color, and dullness.
B. Set and control the level of isopropyl alcohol content to 5-12%, depending on the water quality and additives used. In special cases, the use of isopropyl alcohol is even less than 5% when using an alcohol-reducing printing system and a highly sensitive refining system. Note: The most suitable wetting agent component is to reduce the consumption of isopropanol and to minimize the concentration of isopropyl alcohol in the workshop near the press.
C. Set the dosage of the dampening additive and ensure that the dampening plate has a lower and stable calcium mineral content through the conductivity test. Ideally, the index is 140-175 mg/L total hardness (deionized water or anti-recommended is highly recommended) Permeate water plus 100-150 mg/L minerals that are beneficial for printing (eg 0.50/o Emidamp dampening solution).
Reference correction icon table
D. Dampening solution temperature should be controlled at 8 to 12 deg C inspection sequence:
(1) Each class passes the (thermometer) to test the temperature.
(2) Test the isopropanol content by (liquid pycnometer),
(3) then test the conductivity (in this order);
If the temperature is outside the specification, you need to adjust the "cooler" setting before measuring the conductivity, as the temperature will affect the conductivity reading.
The isopropanol content should also be measured and adjusted before the conductivity is measured. (We recommend 7-10% for standard dampening additives (Emifount ULX). (Although different presses are slightly different)
If the conductivity is too low, you need to add more dampening additives (see figure) and resetting feeders to compensate (note: most dosing feeders rely on a stable water pressure supply to ensure accurate feeding).
If the conductivity is too high but the dampening is relatively fresh, use water and alcohol to dilute and re-set the feeder to compensate.
If the fountain solution is old, the conductivity will increase due to contamination of the ink and substrate, and in most cases a new fountain solution will be dispensed once a week.
3. Ensure that the achievable film weight is consistent with the color of the target.
Using the spectrophotometer, the target color (customer template) can be used as a reference, and the excellent ΔE is calculated by software. After the maximum value of ΔE is set (say, <5), it is used for quality control. (Note: the opacity and hue of the white primer will affect the hue of light/light drift, so it must be considered). The four-color and six-color ink film weight should be controlled by measuring the solid density on the color control strip. The film weight should not exceed the corresponding ink density value too much, otherwise it may cause malfunctions such as large ink size, dirty plate, and poor curing. The color separation ink density reference values ​​are as follows (for reference only. The ink density values ​​may be different for different ink systems or manufacturers, and also related to matching printers):
The density of yellow ink is: 1.2
Magenta ink density is: 1.4
The density of blue ink is: 1.4
Black ink density is: 1.6
Orange red ink density is 1.5
Green ink density is 1.2
4. Perform the correct preparation procedure.
Maintain a lower ink film weight and dampening solution setting for each printing unit prior to positioning registration.
Once all the plates have been properly registered, slowly increase the film weight of the ink to achieve the recommended reference density value or color target.
Be especially careful where the ink hiding power is low to avoid loss of control due to too fast and too fast setting.
The dampening solution is still set to a lower level and then gradually increased to achieve just enough water to ensure that the non-image portion of the plate is clean.
When the test print is acceptable, the machine can speed up and the dampening solution should be optimized.
5. Ensure good adhesion of the UV printing ink to the primer.
Since the UV printing ink is inconsistent with the curing mechanism of the traditional printing ink, most of the primers suitable for the traditional printing iron (white butyl/base oil) are not suitable for UV printing. UV printing iron must be selected for the primer of UV printing iron ink to ensure its good adhesion with UV printing ink to meet the needs of subsequent processing of printed iron products. The method of checking the adhesion is the same as the traditional printed iron, using the tape method or the nail scratching method.
6. Strictly perform maintenance and maintenance procedures.
(1) Strictly carry out the maintenance and maintenance work of the printing press indicated in the manual.
(2) Replace the old dampening solution at least every week.
(3) Check the output power of the UV lamp regularly and replace it according to the manufacturer's recommendation. When replacing the UV lamp, clean the reflector at the same time.
a) Note: The replacement time of the staggered lamp ensures the most stable output.
b) It is recommended to check the UV lamp output power every few weeks to avoid curing problems (more advice on UV lamp monitoring can be obtained from the ink supplier).
(4) Remove the calcium citrate deposit with a suitable rubber roller cleaning paste every four to six weeks.
Third, the application of computer direct plate making technology in Baoyin Company
With the development of science and technology in the pre-press field, the application of the direct plate-making machine has brought a qualitative leap to the printing and plate-making industry. Direct plate making system is a comprehensive multidisciplinary technology industry, which includes intimate mechanical and optical technology, electronic technology, color digital image technology, computer and software technology, new printing plate and material technology, automation technology and network technology. Automatic production system.
Our prepress prepress has not used the traditional plate making process since the beginning of the factory, but all adopt CTcP direct plate making technology. This is one of the few in the printing industry, and it is the boldest in the printing industry in the country.
<1> Our pre-press workflow customer original - text, image processing - color separation settings - spell large version - stored as EPS file - RIP into 1-Bit Tiff raster file - CTcP plate making The plate is developed.
<II) Working principle and imaging characteristics of CTcP The working principle of CTcP is as follows: In the CTcP process, UV is irradiated onto DMD (Digital Micromirror Element), which has about 1 million micromirrors, each of which is digitally For control, the micromirror is like a pixel (Pixel), which forms a screened image on the plate. The CTcP system's exposure head is extremely accurate, ensuring seamless image stitching after several exposures with an accuracy of 2 microns and an exposure speed of 10 exposures per second.
CTcP has another feature. It uses an exposure technique that is very small square dots (pixels). The size of the dots is between 10 and 28 microns, and the edge of the dots obtained by the printing plate is excellent. Even with lower resolution, CTcP can be used to obtain high quality images. The latest digital dot imaging technology ensures the synchronization of print plate exposure and exposure head movement. Thanks to the US DSI2 technology, the exposure head allows continuous movement while the plate is exposed. This "continuous movement" technology prevents exposure pauses (when the head moves) and ensures the efficiency of the plate exposure.
<3) Advantages of CTcP: CTcP has many advantages, the most obvious being to improve production efficiency, save time and reduce production costs.
1. The traditional printing plate makes both parties satisfied that CTcP means "computer-made traditional printing plate". Our CTcP platesetter works at a wavelength range of 360-450nm, so we can use traditional plates with good quality and durability for exposure. Plate making. The traditional printing plate manufacturing technology is mature and the quality is stable, which not only guarantees the image quality, meets the requirements of customers, but also reduces the cost of our company. This is something that both parties are happy with.
2. Improve the quality of plate making
After direct plate making, images and dots are not affected by the quality degradation in the traditional prepress process, the print quality of the prints is significantly improved, and the positioning is more accurate. Through technical tests, we compared the comparison of imaging effects on different platesetters in the past: the square pixels produced by our CTcP have clear lines and sharp edges at the FM points and 50% AM screens. Other platesetters, such as the thermal and violet laser types, show signs of edge blur due to difficulty in controlling dot gain, which can result in loss of quality during final printing.
3. Higher work efficiency
The computer-to-plate technology completely abandons the film-making process, and the possibility of human error is greatly reduced, which avoids the loss of the traditional film printing network, making the pre-press work more convenient and quick. Our CTcP platemaking machine can be flexibly combined with prepress equipment to provide a personalized solution. For traditional printing plates from different manufacturers, including UV plates, we can adjust the corresponding exposure parameter settings in advance. This process is simple and convenient, easy to operate, and it is almost impossible to adjust the settings of these parameters in the future. The exposure of the edition really realizes "once and for all."
4. The printing customer is more satisfied that the customer is more satisfied with the quality of the printed matter, the printing production time is shorter, the delivery is more timely, the factory operation cost is reduced, and the printing company takes the lead in the fierce market competition.