The hottest CTP system and its influence on printi

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CTP system and its impact on printing quality (Part 2)

question 2: what point sizes do you recommend for imaging and FM printing

creo: according to different CTP systems, all point sizes can be imaged (10~70 μ m)。 For reliable printing, the point size is adjusted according to the printing conditions, paper and its surface roughness according to the different uses of the extruder and the different auxiliary equipment. For sheet fed and web commercial printing, we recommend 20 or 30 μ Point of M. For high-grade printing or special purposes, 10 μ Point of M

esko graphics: all printing plates can achieve the best effect with 20xm dots. Our CTP system can reduce the point to 10 μ M (2540dpi), even 7 μ M (3200dpi), but the whole process needs to be continuously monitored when printing FM

fujifilm: too small a dot will lead to uneven ink absorption of the printing plate, a large number of enlarged printing points, unstable printing process, and it will take more time to calibrate the machine. A 1% fluctuation in the printing process will cause a 5% change in eye tone. Too many dots will produce roughness in the fine level and brightness of the image. Fujifilm recommends a point size of 21 μ m。

Heidelberg: replace the sealing ring or combined gasket in time according to the size; According to the use of the machine and the limited test of the service life of the oil, Heidelberg recommends a point size of 20 μ m。 Printing experiments show that point reduction does not bring visual improvement on the printing sheet, but in order to stabilize the printing process, it needs to increase the cost, so it also greatly increases the risk

krause: for frequency stabilized imaging, Krause recommends the following point sizes: 30lm for silver halide Version (10% at 2540dpi resolution μ 3 of point m × 3 pixels); Polymer printing plate is 20~30 μ m(2 × 2 or 3 × 3 pixels), which depends on the laser intensity and printing endurance

question 3: what are the advantages and disadvantages of the inner drum CTP system and the CTP system that uses only one purple laser diode (405nm) as the light source to image the silver halide plate and the photopolymer plate compared with the outer drum system that uses many infrared diodes (830nm) as the heat source to image the thermal plate

creo: this question involves three printing plate technologies, two CTP structures and two imaging light sources, which cannot be answered in detail here due to space reasons. Therefore, only one aspect is involved: the inner drum and outer drum systems with only one diode have no reliability in terms of diode failure. External drum system with multiple diodes shall have at least 50% reliability. The square point technology using TLV (transmission light valve) can provide 100% reliability due to the built-in redundant components

esko graphics: the inner drum system with purple laser diode is more flexible than the outer drum system with infrared diode. It can better meet the requirements of printing plants by imaging silver halide and polymer plates with six resolutions. For example, 1200dpi is used for printing pocket books, 1800dpi is used for printing local newspapers, 2400 or 2540dpi is used for printing parts, and 3200dpi is used for high-end and safe printing

fujifilm: about the advantages of inner drum/Purple laser diode/polymer printing plate: compared with the investment amount, the productivity is high, the diode replacement price is cheap, and the version replacement is fast. Disadvantages: it is processed under yellow light, and the system stops working when the diode is damaged. Fujifilm's system provides dual lasers, so 50% production can be guaranteed in case of diode failure

advantages of external drum type/multiple infrared diodes/thermal printing plate: the printing plate has a large gradient range and can be processed in sunlight. Disadvantages: high investment cost; Its productivity is low when compared with the investment cost of other systems; The cost of using multiple diodes is high; Due to the different aging degree of diodes, the energy emission is also different

advantages of external drum/GLV technology/thermal version: the printing plate has a large gradient range. It is processed in sunlight, and the energy distribution of all points is uniform. Disadvantages: compared with other systems, which are mainly invested in the middle and low end of developed countries' exports, its productivity is low, the cost of heat source is high, and the production stops in case of laser failure

Heidelberg: infrared (thermal) technology has a wide range of advantageous properties. Violet laser has different properties due to the restriction of silver halide and polymer printing plate. In this way, many manufacturers make thermal plates. Other standards: sunlight (infrared) or yellow light (violet laser) can be used for manual plate processing; Heat sensitive and polymer plates are printed and baked with UV ink; Frequency modulation and fine imaging are available on thermal and silver halide plates. Thermal technology is not suitable for waterless offset printing and processing free plate imaging

L? Scher: advantages of 405nm single beam recorder: the printing plate is static, the imaging time is short, usually only one light source is used, and the focusing range is large. Disadvantages of single beam recorder at 405nm: there is only one diode manufacturer, and the diode service life is 5000~10000h; When the diode is damaged, the system will shut down, which limits the use of large size. The silver salt plate cannot be baked. There are few plate manufacturers. The cleaning cost of the developing processor is about 4 coefficients higher, and the price of chemicals is about 3 coefficients higher. With limited sunlight treatment, the printing plate resolution is low

advantages of the 830am thermal recorder: the printing plate is static (only on the xpose model), there are many manufacturers of diodes and printing plates, the printing plate is processed in sunlight, the printing plate price is low, the chemicals are environmentally friendly, some positive and negative plates can be baked, and the system does not stop when the diodes are damaged. Disadvantages of 830nm thermal recorder: high laser energy and multi beam lens group are required, and the focusing range is small. The future belongs to processing free printing plate

question 4: how to evaluate the point sharpness and imaging quality of inner drum and outer drum systems with light source or heat source

creo: the structure of CTP system is different whether it is fixed focusing according to plate thickness or continuous automatic focusing. Only auto focusing ensures accurate and stable point formation. Poor focusing or large focal depth can not reach the quality of continuous auto focusing. Because only a few manufacturers integrate continuous auto focusing in their systems

esko graphics: CTP plates can be imaged equally well with both system structures. In the inner drum, both single beam and double beam can be imaged with flexible resolution and point size. The outer drum type rotates slowly, requires many diodes, and the point size is fixed

fujifilm: the point definition of thermal system is slightly higher than that of polymer system. The difference between the two lies in the resolution of the printing plate, not in the light source or heat source

krause: the combination of CTP system with violet laser diode and good beam focusing and photopolymer printing plate can present outstanding image quality in printing plate and printing

lithotech: on the external drum system, due to the short spacing between the imaging light source lens group and the printing plate, this technology is homogeneous and insensitive to vibration and oscillation. This produces excellent imaging quality. The inner drum system will produce large errors due to misalignment and mechanical wear after long-term use. There is no significant difference for new systems with good regulation and standards

L? Scher: because the thermal printing plate has dual properties, its point definition and resolution are much higher than those of silver salt plate and photopolymer plate

fujifilm: the price difference mainly lies in the laser technology, not in the inner drum or the outer drum. Restricted by high-power laser, the price of thermal system is 20%~30% higher than that of polymer system

question 5: how long is the service life (imaging hours) of purple laser diode and infrared diode

creo: infrared diode about H

esko graphics: about 25000h for purple laser diode and 8000h for infrared diode. The cost of GLV (grating light valve) technology is quite high, because the entire optical system needs to be replaced

fujifilm: about 5000h for purple laser diode and about 1000~5000h for infrared diode

Heidelberg: violet laser diode about 10000h, infrared diode about 5000h

krause: our violet laser diode guarantees 10000h imaging, which is equivalent to 70cm × There are about 240000 printing plates with the size of 100cm

L? Scher: our xpose system works with 1W laser diode, and its service life will reach 25000~50000h

question 6: what is the price for replacing purple laser diode or infrared diode and a full set of imaging head

creo: the imaging head or optical system is not only composed of diodes, power supply components and some other components, but also integrates other important components, such as continuous automatic focusing system or redundant diodes, so the price is certainly higher. It is recommended that a maintenance contract be concluded to solve the replacement problem, so that the problem of asking the price can be eliminated

esko graphics: the complete laser/mirror unit includes violet laser diode, about 7000 euros; The complete imaging head of the external drum system is about 25000 euros

fujifilm: the purple laser diode plus installation cost is about 13750 euros, and the infrared diode is about 1350 euros (including installation). The thermal system uses 16~64 infrared diodes. Some systems require replacement of the full imaging head

Heidelberg: the violet laser diode is about 9000~10000 euros (the whole lens), the infrared diode is about 1000 euros on the 32 channel head, and about 1500 euros on the 64 channel head

question 7: how much time does it take to calibrate, check and adjust each week

creo: as far as the square point imaging system is concerned, Creo's CTP system actually does not need to spend time to calibrate and check

esko graphics: the platedriver CTP system can output and inspect test strips for the global medical device market in 30min per natvar factory in China

Heidelberg: after installing the recorder for the first time, it is not necessary to spend time on calibration, inspection and control for imaging. Silver halide plate development takes time to clean up. In order to visually assess the quality of the whole process, we recommend using our measurement and control strip on each printing plate

krause: a sensor is installed in the optical path to collect diode power and adjust automatically. According to different environmental conditions, we recommend cleaning the unidirectional mirror every week

lithotech: our recorders are automatically adjusted. Only when the plate is changed, the sensitivity changes by 10%, requiring laser power matching. It takes about 10min

L? Scher: weekly test focus is recommended (not mandatory). In addition, the measurement and control strip is imaged on each printing plate and inspected regularly

question 8: what technological innovations will drupa demonstrate? For example, can GLV (grating light valve technology) crowd out the external drum system

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