Abstract: The invention relates to a gathered tubular film (12), especially consisting of artificial sausage skin, which is concertinaed to form a tubular caterpillar-type element. Until now, in order to gather as large a length as possible of the tubular film (12) to form a tubular caterpillar-type element of a certain length, methods have involved increasing the compression of the tubular caterpillar-type element. The aim of the invention is to achieve the same objective by providing a tubular caterpillar-type element having an outside diameter which is at least 10% larger than the outside diameter of the tubular film (12). In order to achieve this, the tubular film (12) is caught at certain points by suction nozzles on the gathering tool, and is pulled radially outwards.