Described is a ultrasonic welding of laminates, more particular to the use of ultrasonic energy to create stable perforations in a laminate, in particular a laminate that includes a silicone gel. Specifically, a perforation element is provided, that is optionally part of array of perforation elements, which perforation element or array of perforation elements is advantageously used in an ultrasonic welding device and in a process for continuously introducing perforations into a laminate.