A laboratory rubber stopper or a rubber bung or a rubber cork is mainly used in chemical laboratories in combination with flasks and test tube and also for fermentation in winery.[1][2][3] Generally, in a laboratory, the sizes of rubber stoppers can be varied up to approximately 16 sizes and each of it is specific to certain type of container. As the rubber stopper is used in many experiments, some specific experiment requires a specific material. For example, the M35 Green neoprene stopper is for chemical resistance. For food fermentation, M18 white natural gum is preferred. For high temperature application, red or white silicone rubber stoppers should be used.
- ^ US 2196785, Takiguchi, Ei, "Rubber stopper for bottles, jars, vessels, and like containers", published 1940-04-09
- ^ US 2289677, Perelson, Harold N., "Rubber stopper", published 1942-07-14
- ^ US 2669370, Royall Jr., Ivey G., "Rubber stopper", published 1954-02-16, assigned to Goodyear Tire and Rubber Company