CD printing quality control points and operating experience (below)

At present, China's CD-ROM printing has not yet introduced CTP (computer-to-plate) technology. Therefore, the pre-press link still uses the traditional pattern-making method. If the customer provides an electronic file, the film needs to be output by a laser photosetter. Therefore, the quality of the film will directly affect the final print quality of the optical disc. Depending on the type of printing used, prepress staff should make appropriate adjustments and handling.

According to Mr. Wang Guokang, director of printing technology of Shanghai Xinsuo Music Co., Ltd., the requirements for quality of film production are: the number of screens for screen printing film is controlled at 133 lines/inch or less, and the reproduction scale of screen tone is 10%. ~90%, text, thin line width is not less than 50mm; waterless offset film with the number of lines in the control of 200 lines / inch or less, dot reproduction range of 2% to 98%.

In order to ensure the production quality, Guangdong Weiya put forward some specific requirements for the film provided by customers (for example, screen printing).

1 film requirements are Zhengyang tablets, film on the top.

2 In the main pattern of figures or scenery and some non-solid patterns with dark and light colors, the number of screens should be controlled at 80 to 120 lines/inch.

3 The printed graphic must be within the outer diameter of 117mm and the inner ring diameter of 20mm.

4 There must be an alignment crosshair on each film. It must be marked outward at a distance of 3mm from the outer diameter of the disc (126mm diameter) with a tolerance of 0.1mm. The alignment line is at the top, bottom, left, and right positions of the center of the pattern. The alignment line length is 15mm. The width is 0.1mm.

5 Attach the plate number and printing color number (PANTONE color code) or C, M, Y, K color code to the film surface.

3. working environment

The reasonable control of the working environment with temperature, humidity, and cleanliness can not only reduce the printing of dirty spots, but also reduce the generation of printed static electricity, especially in waterless offset printing. In order to ensure the quality of the optical discs, general optical disc manufacturers require the indoor temperature of the printing shop to be 24°C ± 3°C, relative humidity at 50%, and air cleanliness of 100,000. Enterprises that have passed the international quality standard system certification will also regularly record temperature, humidity and cleanliness.

4. Play against white

In recent years, the powerful optical disc manufacturers in China have launched combined printing equipment that combines screen printing with waterless offset printing, and then use screen printing to achieve white background. Afterwards, four-color offset printing and UV curing are completed on one printing press. Thus, the respective advantages of screen printing and offset printing are exerted. At present, most optical disc printing equipment that adopts the waterless offset printing process must first use screen printing to fight against white backgrounds, such as Henderson and Crown Printing in Taiwan Province. Lei Ming and other optical disc printing equipment suppliers offset press. In addition, the fight against white defects also masks some of the defects in the production process. At present, DVD-based optical discs are printed using waterless offset printing. Since the ink layer is thin, in order to improve the adhesion of the surface of the optical disc to ink, it is necessary to use white ink that is dedicated to the white background before printing.



Source: Printing Technology