Abstract: A method is disclosed of making a component consisting of a substantially cylindrical support through which there is a substantially coaxial orifice and a membrane welded to one end of the cylinder substantially perpendicularly to a longitudinal axis of the support. A substantially plane membrane is welded to one end of a support substantially perpendicularly to a longitudinal axis of the support and, after cooling, the support is torn off the membrane in a direction substantially perpendicular to the plane of the membrane so that a portion of the membrane substantially corresponding to the end of the cylinder remains welded to the support. The method can be applied to making two-part stoppers for straws, in which case the membrane is microporous, hydrophobic, impervious to liquids and permeable to gases and the support is an insert made from a material chosen from an elastomer material, a thermoplastics material and a thermoplastics elastomer material.