This is a great visual of the molding of silicone rubber. Think of the compression mold as a giant waffle maker. The top and bottom half compress a carefully cut and weighed portion of silicone material. Once the mold is preheated to the correct temperature, the mold is then closed under extreme pressure (150 - 250 tons).
During the molding and compression time, when the tool is closed, the silicone fills up the entire mold cavity and is then vulcanized.
To learn more, visit our Rubber Keypad page:
https://www.rspinc.com/capabilities/silicone-keypad/