High-speed rail EMU communication crystal button

The communication crystal buttons of high-speed EMUs are manufactured using the P+R process, where the pre-fabricated crystal buttons are bonded to the silicone panel. The characters on these crystal buttons are printed with colors at the bottom through layer-by-layer silk-screen printing: first, a layer of characters is printed, followed by a layer of background color. By utilizing the permeability of the button surface to display the characters at the bottom, it effectively prevents possible wear and tear of the character marks caused by long-term pressing.