Method of fabricating and devices employing vents

摘要

Vents for containers include a perforated substrate portion (20) of polymer material over which is thermally bonded a gas permeable membrane (30). The thermal bond (31) is direct and adhesive-free so that there is no adhesive available for chemical attachment by materials within the containers (58) and no opportunity for an adhesive to interfere with or block perforations through the substrate.