Mechanism Behind Silk-Screening a CD

The process of printing with screens was first patented by Samuel Simon in the year 1907 and later the design was modified by John Pilsworth to introduce multicolor prints. This marked the development of various new applications that are in use now.

An example of one of these applications is the silk-screening seen in a CD or DVD. The art work on the face of the CD is a type of silk-screening. And the process of silk-screening a CD differentiates an original from a duplicated CD. The silk-screening used is very similar to that used in shirts or other consumer items. Colored UV ink is passed over the screens for each color component that is needed.

The process of silk-screening a CD involves screening devices that have circular spaces on a table top surface where the discs to be screened are placed automatically. The whole process is under the control of a robotic CNC. All movements like placing, screening and removing the disc are done by the robotic arm, which is manned by an operator.

The ink that is to be used is pre measured in a controlled dispenser and it is then spread on the screen by a squeegee. The entire movement is done smoothly and the ink gets evenly spread on the disc. Though the silk-screening (in items like T-shirts) is done by hand, in case of silk-screening a CD the whole process is automated by using the CNC robotic devices.

The table is automated and once color application is over in a particular disc, the table rotates for the next disc to be colored allowing the colored one to dry before the next coat. Thus two sets of CDs can be screened by the skipping process of the automated table, with the system wheel equipped with various sets of colors and screens.

The ink used in silk-screening a CD is specifically designed for the process and while applying the ink only a specific measured amount is spread on the disc surface so that it is not wasted during the application process.

Once the ink application is over, the disc is subjected to curing by UV lamps placed on the table. After the curing is complete, the disc is passed from the UV lamp station to the spindle packing or bundling station.

To give the CD or DVD a polished and sophisticated look, silk-screening is the best option. The CD looks like it is bought from a store and the quality is superior when compared to the one that is done using an inkjet or thermal printing method. In some cases of art works used in discs the inside ring, which is depressed, needs to be filled fully with the ink. This gives the end product a total even surface which cannot be reproduced in a duplicated disc. Silk-screening process is more popular due to the ability of doing complex printing work on the disc surface.

source: Simple Screenprinting: Basic Techniques & Creative Projects by Annie Stromquist