via shaking the flask or may require that the contents be kept inside the flask and prevented from leaking out. In all cases, the bung keeps the experimentation environment sealed so that liquids or gases cannot escape (or enter). For applications that place higher demands on the bung in terms of temperature and mechanical stability or solvent resistance, standardized glass stoppers and connectors are preferred. Bottle stoppers made from gutta-percha, a natural rubber that is both chemically resistant and thermoplastic, were the first product of the Gutta Percha Company, better known for making submarine telegraph cables. See also Bunghole Cork borer Closure (container) Hutchinson Patent Stopper References Yam, K.L., "Encyclopedia of Packaging Technology", John Wiley & Sons, 2009, Soroka, W, Illustrated Glossary of Packaging Terminology Institute of Packaging Professionals, Laboratory equipment Seals (mechanical) Wine packaging and storage Containers es:Tapón he:פקק la:Embolus new:बुङ